Abstract: The project has determined that the cogeneration of energy with a four-stroke internal combustion engine utilizing a Rankine cycle is technically feasible. Although technically feasible, much more system design optimization is required to make the system economically feasible. This paper outlines the circuit design and modeling of a Rankine cycle cogeneration system for a Kohler Power Systems 800kw Diesel generator set.
To design the cogeneration system, two software models were generated using a Engineering Equation Solver (EES) computer program. EES is a software package used to solve engineering problems and has fluid property query functionality which makes it ideal for thermodynamic system modeling applications. The primary EES cogeneration simulation model was used to simulate and optimize the system. The secondary EES heat transfer coefficient model was used to determine the heat transfer coefficients for the waste heat recovery heat exchangers. Results from the heat transfer coefficient model were entered into the cogeneration simulation model to size the waste heat recovery heat exchangers based on the desire performance requirements. The simulation model results were then utilized to determine the economic feasibility of the system through the use of a net present value (NPV) and internal rate of return (IRR) model.
A percent increase in net output of up to 21% was possible, but resulted in a NPV of negative $2,700,000. More economical design scenarios were explored, but no options resulted in a positive NPV. Further heat exchanger design is required to increase the compactness of the waste heat recovery heat exchangers while decreasing the associated cost. In addition, utilizing steam as the working fluid results in very low boiler and condenser operating pressures. This resulted in an application where the turbine required was not commercially available. A specially developed turbine is needed if steam is selected as the working fluid. If R-134a was selected as the working fluid, a turbine is commercially available. However, with R-134a as the waste heat recovery efficiency is much lower, resulting in an extremely large heat exchanged and low NPV. Additional heat exchanger design optimization and turbine development will help to deliver the economic benefits of Rankine cycle cogeneration. A pre-engenered skid encompassing all the design improvements can be developed and provided by the generator manufacturer. The pre-engineered skid would reduce reoccurring engineering costs and potentially deliver an economically feasible cogeneration system, while providing all the environmental benefits of reduced net fuel consumption.
Abstract: This project created an automated mechanism for review and approval of content for the gemedicalsystems.com website. Existing manual processes for paper and written product information were inconsistent, difficult and inefficient for generating web content. There was an opportunity to develop automated and streamlined processes for review and approval of web content. The MarComm, Legal, and Safety teams, along with content authors needed to participate in a standardized review and approval process for content deployment on the gemedicalsystems.com website. This project made review and approval by various teams within GE Medical Systems an automated process.
This project followed the Six Sigma quality methodology approach. This is the engineering methodology adopted by the Information Technology group at GE Medical Systems. The methodology is standardized in GE and was deployed in this project using the Define, Measure, Analyze, Improve and Verify phases of Six Sigma. The application was placed into operation using the production system in a controlled environment.
This project resulted in an automated content review process that supported the business needs. Review Cycle times were reduced from 115 hours to 45 hours. Business needs of documentation were satisfied. All business units of GE Medical Systems were supported. Marketing, Safety and Regulatory Engineering, and Legal reviewers are supported in the new process.
Abstract: The purpose of this project is to determine the effect of changes in testing parameters such as the magnitude and direction of electric and magnetic fields, and gas composition (helium gas) when using the Penning discharge for the testing of vacuum interrupters. This paper seeks to determine how these parameters influence the discharge vs. pressure curves for different types of vacuum interrupter designs. Several references were analyzed and then used to examine the basic fundamentals of gaseous discharges, the basic theory behind the Penning discharge, and charged particle motion in crossed fields. Experimental data was then taken to verify the effects of changes in various testing parameters for the pressure testing of vacuum interrupters.
A theoretical model was developed based on a particle balance within the vacuum interrupter under steady state conditions. In conjunction with the theoretical model, the potential distribution, electric field distribution, and electron trajectories for each vacuum interrupter configuration were evaluated using finite element analysis software. The results of the software analysis indicate that the electrons produced by the discharge move in complex helical paths. The electrons tend to become confined in specific regions of the vacuum interrupter due to the combination of the effects of crossed fields and the electrical repulsion that is imparted to an electron that is constrained between two negatively charged surfaces.
The results of the experimental data, when combined with calculations based on the theoretical model, indicate that the electron density tends to remain constant in the regions of electron confinement due to effects caused by the buildup of space change. In addition, the non-linear characteristics that were measured for the discharge current versus pressure curves can be explained by effects due to secondary ionization caused by electrons that escape from the confinement region.
Test results indicate that the Penning discharge has a reduced sensitivity to helium. Due to the smaller molecular cross-section and the higher ionization potential of the helium atom, the magnitude of the discharge current that is produced at any given pressure is reduced by a factor of 0.18 that of air. Because of this, the upper test limit when testing vacuum interrupters processed in a helium atmosphere should be adjusted to account for this reduced sensitivity.
Abstract: The purpose of this project was to investigate a typical engineering problem by developing a thermal model for predicting the surface temperature for a subsystem (the patient opening) of a Magnetic Resonance Imaging (MRI) system. The inputs to the model were a randomized series of high current switching waveforms that were derived from a statistical analysis of the daily imaging sequences performed at an MRI imaging clinic. The purpose of the investigation was to understand if existing limits for a system safety parameter could be exceeded. The safety parameter that was examined is the average surface temperature of the patient bore of the MRI system. The methodology that was employed for this project was the collection and statistical analysis of operational logs from several MRI sites, and the development of a Monte Carlo type simulation for the heat inputs generated from the operation of the MRI scanner. These inputs were then fed to a block simulation model, which in turn predicts the MRI bore temperature. For completeness, two simulations were run simultaneously to reflect both actual operating conditions (power input and intersequence delays), and worst-case conditions (power inputs without intersequence delays).
The end result of this simulation and analysis was the determination that, in the absence of other mitigating factors (heating due to parasitic currents in antenna structures), the MRI system under study, operating at specified ambient temperature conditions, can tolerate an increase of 1.5kW and 2.0kW average power before the risk of exceeding the thermal limits for the surface of the patient bore exceeds 1 failure per 10 years of operation. Ten years is the estimated life cycle of the MRI system. During that time, a scanner is expected to perform an average of approximately 365,000 scans.
In addition to this simulation and analysis, the model developed in this project will be utilized to evaluate future modifications to the MRI system. For example, determining the effects of increasing gradient RMS current limits, or evaluating the thermal effect of new imaging sequences prior to deployment to Customers. The use of this model will ensure patient safety, and compliance with regulatory agency guidelines.
Abstract: This capstone project is intended to provide an economic model for the design of a biodiesel refining facility using the Biox Process developed by Dr. David Boocock of the University of Toronto. The capacity of the facility is designed for four million liters of biodiesel fuel annually; however, the process is scaleable, and a capacity of up to ten million liters annual production rate is reasonable. The plant design is not intended to be feedstock specific; however, feedstocks with free fatty acid (FFA) contents between 0-5% are recommended. A feedstock with greater than 5% FFA may require pretreatment.
Several aspects of the plant were analyzed including thermo-fluids, chemistry, equipment and economics. Thermo-fluid principles were utilized to develop a theoretical model of how a biodiesel plant of this size might operate. This entails equipment analysis and chemical, mass, and energy balances.
Several pieces of equipment were researched during the course of this project in order to optimize equipment to produce biodiesel as efficiently as possible. The equipment includes: lobe pumps, plug flow reactors, tanks, centrifuges, and flash chambers. To determine if the design of the biodiesel plant was economically viable, a spreadsheet was developed. Using data from the utilities that serve the Milwaukee area, a biodiesel plant would achieve a net loss of $213.70 per hour at a diesel competitive price of $2.55 per gallon for biodiesel and an open market price for feedstock of $1.29 per gallon. However, a profit can be made if the feedstock is a negative cost or the price of petrol-diesel approaches $4.00 per gallon. Note: a negative cost for the feedstock implies that a restaurant or cafeteria would normally have to pay for the feedstock to be removed. Graphs have been included in the results section, which show a sensitivity analysis for the economic data. Furthermore, due to the nature of commodities, the economic analysis can vary based on chemical prices, utility rates, cost of labor and other factors. The calculations from the model should be used as a guide to determine if it is cost effective to build a biodiesel refinery, not as a final conclusion. Economic conditions can improve with respect to biodiesel production and technological advances may improve the economics as well.
Abstract: This project is an investigation of optimization techniques for music-signal compression algorithms. More specifically, the details of the MP3 algorithm and similar compression algorithms have been researched and ways to alter and expand on those characteristics, the filter bank decomposition in particular, have been identified. The primary focus is compressing audio signals for downloading music off the Internet.
The principal hypothesis tested for this project was that replacing the filter bank used in the MP3 algorithm with a discrete wavelet transform would be beneficial to the coding process and help to increase the compression ratio. To test the hypothesis, a working testable audio codec (coder/decoder) has been built and implemented in MATLAB using the Wavelet Toolbox and originally designed MATLAB source codes. In addition, a subjective sound-quality test has been performed on human listeners following the hypothesis test model, borrowed from classical statistics. Bit rate estimates were calculated in MATLAB to gain knowledge of the codec and used to make further hypotheses regarding the tradeoffs between signal distortion and bit rate. It was found that the wavelet transform is a powerful tool that should be utilized in the signal compression world.
Abstract: The purpose of this study is to design, simulate and validate the design of a non-contact current measuring sensor and filter circuit that could be the basis of a self-calibrating medium voltage capacitor switch control. The closing of a medium voltage capacitor switch, and the subsequent insertion of shunt capacitance onto an electrical distribution line, results in the generation of disruptive transients. A sensor and filter circuit that is capable of properly detecting and measuring the transient may allow a controller to precisely time the closure of the switch in order to reduce the transient to acceptable levels. The existing products in the marketplace are functional at transient reduction but are not universally applied because of the product costs. One of the major cost challenges of such a design is the sensing of current on electrical lines running up to 38,000 volts. The proposed system would reduce the severity and occurrence of damaging transients by providing sensor, filter, and feedback timing correction scheme at minimal cost.
An inductive sensor and filter circuit is proposed and is shown to be effective as a sensor capable of measuring current flow in a conductor with adequate clearance to be added to a standard switch design. The sensor output requires conditioning to be compatible with standard microprocessor inputs. A filter design for this purpose is proposed and is shown to be adequate to condition the signal and obtain the desired signals needed for switch timing feedback. The filter was analyzed with simulation software and shown to perform the desired function. Finally, validation of the sensor and filter system are presented using a transient generation test fixture.
Abstract: The project involves serial digital multi-gigabit communication systems that are emerging for use in chip-to-chip applications in digital systems. These systems communicate data using very high speed point-to-point serial links in a switch fabric architecture between processors and peripherals in digital systems. The major purpose of this project is to develop two reusable building blocks for use on projects containing serial digital multi-gigabit communication systems. The reusable building blocks are an error correcting code (ECC) encoder and decoder appropriate for these systems and a bit-error-rate-tester (BERT). Both of these building blocks are designed using digital logic in Very High Speed Integrated Circuit Hardware Description Language (VHDL) to be implemented in a field programmable gate array (FPGA) that contains multi-gigabit serial transceivers.
The project includes a detailed investigation of serial digital multi-gigabit communication systems that was required to determine an appropriate ECC design. Elements of the investigation include the communication channel and bandwidth, random and deterministic noise sources and effects, characteristics of the transmitted data, and a comparison of different types of ECCs. The ECC designed in this project consisted of a maximum run length code state inside of a w-error correcting primitive BCH code. The overall code word size is 63 bits. A detailed description of the logic design for this code is provided.
The project also includes some investigation into bit-error-rate test methodologies. Some information on the statistical nature of bit-error-rate measurements is developed as well as discussion of different types of data patterns. Three bit-error-rate test patterns are implemented in the BERT block and they are a programmable data word pattern, a 211 – 1 pseudorandom bit sequence (PRBS) pattern, and a 231 – 1 PRBS pattern. A detailed description of the logic design for the BERT block is provided. The design of the BERT block is efficient enough to support data rates up to the maximum of the Altera Stratix GX FPGA.
In the project, the ECC block is implemented in an Altera Stratix GX FPGA. The BERT block is used as the data source and also to measure the bit error rate. The bit error rate performance is compared for the coded data and the uncoded data running at approximately the information data rate of the coded data. Two physical channels are used in the comparison, one 10-inch backplane channel and one 40-inch backplane channel. The ECC block design of this project is not effective in the 40-inch backplane channel and results in a higher bit error rate than uncoded data. The ECC block is effective in the 10-inch backplane channel, but the bit error rate without coding is already much lower than the target rate. The test results indicate that the ECC block may be more effective when used with equalization. They also indicate that a code with similar error correcting capabilities but a higher code rate may also improve performance, but detailed investigation of this is left as future work.
Abstract: For this project, different models for chiller plants and cooling towers were explored in an effort to develop an optimization algorithm that would control the systems to meet specific loads while using the lowest amount of energy possible. The Gordon-Ng universal chiller model and a biquadratic regression model were examined for three chillers connected in parallel, while Braun’s NTU-effectiveness model and Lu and Cia’s universal cooling tower models were examined for controlling three cooling towers.
The biquadratic regression model for chillers was selected and solved as a mixed integer linear programming, using a slack variable to approximate the quadratic elements. An alternative control scheme was created for comparison featuring two chillers for loads exceeding 400 tons, and three chillers turned on for loads exceeding 900 tons, with the loads divided equally among the chillers in each scenario. A simulation was created to show the load profile for a week. The optimization control resulted in a 4.9% power savings over the week over the alternative scheme.
The cooling towers were arranged such that each tower was dedicated to one chiller. The fan affinity law prevents using biquadratic models to find the optimum power consumption for towers directly. Instead, Braun’s and Lu and Cia’s models can be employed to find the optimum air flow from the towers, which can then be used in the fan affinity law to find the amount of power needed by the fan. Braun’s model was used for a variable speed fan and compared to a fixed-speed fan with the same designated air flow and designed power. Braun’s model saved 65.8% power over the course of a week.
Abstract: The main objective of the Master of Science in Engineering (MSE) capstone project was to determine the feasibility of achieving signal interoperability between the two principal third generation (3G) terrestrial wireless cellular systems, namely Wideband-Code Division Multiple Access (W-CDMA) and Code Division Multiple Access2000 (CDMA2000). In order to study the feasibility of achieving signal interoperability between the two 3G systems, the evolutionary path developed for the migration of second generation (2G) Global System for Mobile Communications (GSM) and 2G IS-136 to the intermediate 2.5G system was studied so that the concepts that were used to allow the two dissimilar 2G systems to interoperate with each other, resulting in a defined intermediate 2.5G system, could potentially aid in the efforts to have the two dissimilar 3G systems interoperate with each other.
It was determined that, analogous to the 2G systems, there is no signal or network interoperability between W-CDMA and CDMA2000, and it would be difficult to achieve interoperability between the two 3G systems without forcing one system to adopt the characteristics of the other system. However, unlike the 2G case in which the 2G GSM system was clearly the superior system compared to the 2G IS-136 system and therefore it was justifiable to force 2G IS-136 to migrate towards 2G GSM, neither 3G system displays marked superiority over the other. Therefore, it would be difficult to conclude which 3G system should remain stationary and which should adopt the signaling and networking protocols of the other. Consequently, forcible modifications to either one of the 3G systems is not likely and interoperability between the two systems is not feasible.
However, due to the inherent nature of CDMA, which is an interference-limited system, whereby the introduction of each active mobile user increases the overall level of interference at a particular cell in a gradual manner, it is feasible for W-CDMA and CDMA2000 to coexist with each other albeit with predictable degradation in performance.
This paper shows that signal interoperability between W-CDMA and CDMA2000 can coexist and quantified the degradation in performance both theoretically as well as using Matrix Laboratory (MATLAB) based simulations.
Abstract: The purpose of this project was to develop a linear optical absolute-position encoder for electro-hydraulic systems operating in uncontrolled environments that can meet the specifications for a magnetic position encoder. The system must be able to provide a resolution of position of 0.1 mm, a resolution of velocity of 0.1 mm/s, and an accuracy of velocity of ± 2 mm/s. Several optical absolute-position encoder system designs already exist which can meet these performance requirements; but their effectiveness in uncontrolled environments is unknown.
Large symbols were used for the code pattern so that obstructions and blemishes from dirt and debris would not significantly affect the reading of the individual sensor. Gray code was selected as the coding scheme to allow for simple error correction. Photodiodes were used to read the code pattern in an analog manner to allow for very high resolution in measurements. The analog signals were then converted to their digital equivalents to determine the position of the sensor assembly. The use of fuzzy logic as a means of error correction was also investigated.
The system was determined to be capable of calculating position with a resolution better than 0.01 mm. Fuzzy logic was demonstrated to be capable of inferring the sensor signal for the ‘high-frequency analog track’ so long as the other signals were ideal.
Abstract: Objective: The objective of this project is to research and design a system for detecting leaks in an automated animal drinking system using neural networks. Detecting a leak using a rule-based algorithm when a mouse drinks 3-6 ml per day is a daunting challenge. Neural networks have the ability to train on patterns, detect those patterns and thus discern anomalies that occur. It is the intention of this project to implement Artificial Neural Networks to detect leaks in an automated animal watering system.
Methodology: Research was conducted with 58 mice on an Edstrom Automatic Watering System using an Alicat L-series flowmeter. The flowmeter was monitored, collecting flow rates every minute for over six months. Collected data were used to train two neural networks in series. First, an unsupervised, self-organizing map clustered the input data. Second, a supervised, back propagation network was trained to detect leaks greater than one milliliter per minute. Neural network algorithms were designed and written with the application program Matlab.
Major findings: Testing proved that the system could detect a leak over one milliliter per minute. A leak was artificially created to test the system. Output from the network displayed, with 100% accuracy, that this artificially created flow was a leak. The system also detected, with 100% certainty, an actual leak that had occurred during the course of this research.
Abstract: Camless engines require independent gas-valve actuators which can provide accurate control, sufficient force, and require only a small percentage of engine output power. A valve actuation system concept with apparent advantages in these areas over existing systems is proposed. A potential design of required system components is presented and dynamic simulation included which make feasibility conclusions from the standpoint of performance, packaging, and power efficiency. Trends toward downsized gas and diesel engines with high fuel efficiency and high specific power output fully warrant this research.
Based on consideration of valve actuation cycles and hydraulic power efficiency, an open-center hydraulic system schematic with series valves is the baseline of this project. Compact valve actuation and hydraulic spool-valve components were designed which would be suitable for typical engine layouts. With this potential design, hydraulic system simulation models were developed to predict the dynamic performance, power consumption, and tolerance to the temperature range of the application. Operating conditions and performance specifications were determined from technical paper references and consultations with Motorola engineers.
The modeling results presented in this report conclude that the proposed system is feasible from an engineering standpoint. Further development and testing would be required to determine this completely. It was confirmed that it may require as little as 1-2% of engine output power to operate this considered system. Technical journals estimated the power input for comparable prior systems at 4-7% of engine output. This input power affects the overall fuel efficiency and net gain of camless engines. Additionally fluid temperature variation was found to have a reduced impact on this system compared to a dynamic model the author created representative of prior-art metering systems.
Simulation results indicate the system may lend itself well to open-loop control, which would improve cost and reliability significantly by eliminating position sensors on each valve. Building on the results of this project, development of microprocessor control algorithms and laboratory testing of a prototype would be significant next steps.
Abstract: Infection control enclosures are used in hospitals and healthcare facilities to enable construction and maintenance workers to access the area above the ceiling grid while allowing no dust or airborne particles to escape into the healthcare environment, where patients with immunocompromised systems are present. The purpose of this project was to improve upon the present infection control enclosure concept in the areas of ease of use and human factors, including the safety of the individual utilizing the enclosure, while also keeping an effective negative pressure between the unit and the surrounding space with the use of a HEPA (high efficiency particulate air) filtration unit.
One main goal in improving on the human factors of this project included designing a system that no longer required the user to utilize a ladder within the enclosure. This involved evaluating different design options for wall types, connection of enclosure walls to the ceiling grid, mobility of the enclosure, and easy HEPA filtration unit access.
Upon completing the building of a prototype of the new enclosure, ease of use tests and surveys were administered to ten individuals for rating purposes, as well as determination of further improvements. Overall, of the sixteen line items ranked between one and ten, the mean value of fourteen of them ranged between 9.0 and 10.0. The remaining two items ranked at 8.9. These values indicated that definite improvements had been made in the areas of ease of use, safety, and the use of the HEPA filtration unit in the new infection control enclosure.
Abstract:The purpose of this project is to understand and control motion of a CT gantry to minimize degradation of the CT image throughout a product’s life. This project quantifies the relationship of gantry imbalance, structural stiffness, and motion. Gantry imbalance was predicted with a Monte Carlo simulation of mass and CG differences in the replaced components. The motion due to imbalance was predicted using analyzed values of structural stiffness. The predicted motion was confirmed experimentally by varying imbalance and measuring the motion. Motion artifacts were validated by adding imbalance to a CT scanner and showing that the added motion created an image artifact.
The results of this study show the relationship between imbalance, motion, and artifacts. Gantry motion is a linear function of imbalance. The type of imbalance determines the type of motion. These motions can create image artifacts. Imbalance (and motion) can be controlled by implementing a balancing process and/or controlling the component variations that cause imbalance. These results can be applied to prevent motion related artifacts.
Abstract: The main purpose of this MSE Graduate Capstone Project is to design and simulate a pneumatic/hydraulic test stand circuit in which the output conforms to the American National Standards Institute (ANSI) and National Fluid Power Association (NFPA) recommended standard T2.6.1 R2-2001.
The reason this project was undertaken was to determine if a pneumatic power source, could be used as the main driving force to test hydraulic components. Therefore the author is using an air over oil liquid pump to convert the air pressure (input) to oil pressure (output) thus feeding the circuit. This would be beneficial for companies involved in the fluid power industry since testing of their components would be easily facilitated by connecting the test circuit to an air-line and a 120V power source. This would allow test stand portability since the pneumatic and electrical power sources needed are readily available in most organizations.
This project will describe the necessary components used in the circuit, their mathematical models and assumptions the author made. The mathematical models of each component will be represented by block diagrams and subsequently simulated on Simulink software. The validation method employed will be to use Simulink software to simulate the test circuit (non-linear) thus determining if the output conforms to the specified criteria represented in ANSI/(NFPA) T2.6.1 R2-2001.
Results from the calculations, mathematically modeling and test circuit simulation conclude that the final output does conform to NFPA standards. The test circuit can test components at using an input air-pressure of 105 psi at test pressures ranging from 3,000 to 3,400 psi and test volumes up to 80 in3 (44.33 oz.). At these maximum test values the cyclic frequency reaches 3.33 Hz and the accumulator is active approximately four times as long as that of the pump.
Abstract: In triaxial compression, the forward strain path in the evolution of the contact distribution, or evolving fabric, has been established in the Jenkins-Strack (1993) continuum model. Arbitrary, alternate reverse paths have not been studied. The focused area of research is confined to tracking the evolving fabric in the reverse “loading” strain path. We then postulate the effects of the fabric on average stress. An introduction on the forward “loading” straining equation and the solution of Jenkins-Strack’s equation 42 is presented. Dr. V.C. Prantil, Department of Mechanical Engineering at MSOE, has numerically solved this transcendental function in terms of material parameters described as being proportional to the hoop strain and pure shear strain. He has modeled the applied strain to a granular material in triaxial compression as a manageable quadratic function of pure shear strain. This quadratic relation, key to this area of research, expresses the volumetric strain as a direct function of pure shear strain.
We reasonably resolve how the probable contact distribution evolves about a central reference sphere when the load is removed and reverse “loading” straining is applied. The Jenkins-Strack (1993) formulation for particle deletion angle is applied along with a description of the evolving fabric as a function of contact angle theta, where a region of loss-of-contacting, deleting particles develop along the forward strain path. Particle contacts become re-initiated while following arbitrary, alternate reverse strain paths. Our solution uses relatively simple vector mechanics to track a contact point on a chosen reverse path within a naturally developed strain field. We ultimately take both the changing forward path deletion angle and the reverse-path-dependent re-initiation angle results and cast the evolving contact distribution as a complete strain circuit.
Abstract: If realized, the camless internal combustion engine offers significant advantages over the engines on the market today in the areas of efficiency, fuel economy, and emissions reduction. One barrier to development is the amount of power consumed by the camless valvetrains when compared to standard valvetrains. In previous work completed, a model of a system that exhibited much lower power consumption was created in AMESim.
As a next step, this paper details the development and simulation of a control system for the model. A method of linking Matlab/Simulink with AMESim, each used to simulate the controller and physical system respectively, was proven and used. The controller developed for the simulation utilized a position feedback signal from the actuator. A second reference signal, engine crank angle, was also used to generate the crank angle and crank speed of the engine. Both signals, in the simulation, were sampled at a rate of 1E-5 seconds.
The simulation results showed that the controller developed is capable of adjusting to changes in engine speed, operating temperature, and flow rates. Errors resulting from changes in residual cylinder pressure were not acceptable and on the order of 5 degrees for valve opening angle at 5000 RPM with a one bar change in residual cylinder pressure. Possible system design changes and controller upgrades to reduce this error are discussed. Changes in input displacement were also examined with the worst case error identified as less than 0.75 millimeters after a single cycle. Using the outlet valve of the system as a means to control seating velocity and closing angle was also investigated. The results showed that, as currently designed, it is not possible and other possible solutions to control these parameters are discussed.
Abstract: Project Objective: This thesis presents the development and simulation of position-velocity PID control algorithm for a numerically stiff non-linear hydraulic XY axis gantry system.
Methodology: The tuning of the control system and sensitivity analysis of the bulk modulus, supply pressure, and tank pressure on the non-linear system equations was performed with the use of an integrate time-squared error-squared per sample (ISTE/S) performance index.
Conclusions: Several major conclusions were obtained from the study. 1) In general, the higher operating supply pressure the less error, as measured by the ISTE performance index, occurs for both the position and velocity control loops. 2) Performance is improved when the tank pressure is minimized for any fixed supply pressure. 3) The first two conclusions are valid if and only if the systems bulk modulus is maintained within an acceptable operating range of 88,000 to 220,000 PSI. 4) The use of ISTE/S performance index is an effective method to perform sensitivity analysis of simulation models. 5) The system’s ISTE/S performance remains essentially constant (with fixed supply, tank pressures, and controller gains) until the change in bulk modulus reduces the system’s natural frequency and damping ratio to the point the PID controller parameters need to be adjusted. Typically, only the integration term of the PID controller is required to be retuned to account for the change in system’s natural frequency and damping ratio. 6) Trajectory planning algorithms are necessary to specify time based motion laws.
Abstract: The objective of this project was to complete the redesign and analysis of a human powered vehicle (HPV) called the Heliocycle, which is an existing tricycle (also referred to as trike). The Heliocycle was a Senior Design Project that was completed at the Milwaukee School of Engineering (MSOE) by Bradley Helm, Kelly Bauserman, Michael Caelwaerts, and Nicholas Weis from September 2014 through May 2015. Since the Heliocycle’s debut in May 2015, it has been showcased and ridden, gaining exposure and feedback. In addition, a company (Omnium Cycles, LLC) was formed around the Heliocycle, and the Heliocycle received a provisional patent. This redesign was completed to improve the original design, based on knowledge gained through fabricating the initial prototype and feedback gathered during showcases. A brief market analysis determined a need for this trike and defined the target audience who would be most likely to buy and use this product.
In order to complete this project, a five-stage design process was followed. Throughout these stages, this project involved engineering design and analysis, which included the selection of materials, mechanics of materials, and finite element analysis, as well as some minor business aspects. The analysis was completed to confirm the design would be safe and withstand the stated maximum load established during the design. There was communication with the potential fabrication team (FT) to ensure that the design is feasible to build. After the completion of this project, Omnium Cycles may build and test the second prototype of the Heliocycle. Note: the fabrication of the redesign was out of scope for this project.
Abstract: This report provides a literature review of existing electromagnetic pulse generating devices and the methods by which these pulses are produced. More focused research is performed into the theory behind magnetic flux compression generators with the goal of providing a basis of knowledge with which to analyze a patented electromagnetic pulse generator design.
The design of a proposed electromagnetic pulse generator is analyzed. Design elements of this generator include an energized solenoid producing a magnetic field to be compressed and a series of folded parallel plate capacitor banks which discharge the solenoid rapidly via a travelling spark. Analysis and experiment indicate that the design transfers an electromagnetic pulse to a low-impedance load, but magnetic field compression does not occur. The design differs fundamentally from flux compression generators in that it achieves a pulse through energy conservation, not flux conservation. As a result, the current increases as a factor of N loops in the coil, whereas with flux compression the current increases by a factor of N2. Experimental results indicate the device functions as the magnetic analog of a Marx generator.
An experiment and results are presented which simulate the travelling spark concept using semiconductor switches in a low current, low voltage, reusable, small desktop model. Electromagnetic pulse characteristics include 50-60 ns risetimes, 4 microns decay time constant, and current multiplication of a factor of five, into a 10 omega non-inductive load.
Abstract: Because of their inherent complexity, including many possible variables and many possible outcomes, projects carried out by companies typically require that some amount of risk be assumed by involved parties prior to the project start. When a company begins to accumulate a large number of projects with high risk, it is important to compare the probability of project award to the probability of detrimental impact to the company. Westinghouse Electric Company currently analyzes risk on a per-project basis; however, the company has no method of tracking and comparing multiple projects and their associated risks. This report describes and explains a capstone design project, whose fundamental purpose was to identify an appropriate risk analysis software package, and then to use the software in conjunction with Microsoft Excel to design and to produce a project proposal risk analysis and risk management software simulation system, enabling Westinghouse to assess the individual and total risk associated with multiple projects.
Project risk analysis is typically complex, and as a result, Monte Carlo simulation is increasingly being employed to assess risk. The demands associated with Monte Carlo simulation invariably entail the use of risk analysis software. Three risk analysis software packages were selected for comparison, including @Risk, Risk Solver, and Crystal Ball. The software packages were compared, and both customer and functional requirements were identified, using quantitative and qualitative techniques and methods, including a Pugh Matrix and a House of Quality (HOQ) Matrix. This methodology identified Palisade’s @Risk as the most applicable risk analysis software. Next, a risk analysis simulation model was built using the @Risk software. The model was then verified in two ways; first, by comparing simulation results with actual historical Westinghouse project data, and second, by constructing a similar model with Frontline System’s Risk Solver, and then comparing the results from both simulation models. Both of these verification methods proved that the simulations produced by @Risk were accurate and repeatable. These results demonstrate that @Risk can be employed in conjunction with Microsoft Excel to produce a feasible project risk simulation system capable of assessing multiple-project risk. This report recommends that the system should be implemented. Accordingly, an implementation plan is featured, which details the resource requirements for the software system, including a $480,200 budget over a 24-month schedule.
Abstract: This MSE Graduate Capstone project describes the design, development, and validation of a software tool-set for the automated data collection and analysis of the American College of Radiology (ACR) Magnetic Resonance Imaging (MRI) Phantom Accreditation testing criteria. ACR accreditation is becoming increasingly more important in the MRI clinical community as well as in the health care insurance industry. ACR accreditation assures that clinical MRI scanners meet a set of minimum quality standards and that those standards are maintained over the operating life of the MRI scanner. The software tool designed and developed for this project is called the American College of Radiology – Phantom Analysis (ACR-PA) tool. The ACR-PA tool was designed to allow any knowledgeable user of the General Electric (GE) MRI scanner to automatically collect and analyze ACR phantom test data in an automated reliable manner in a reasonable amount of time. The data generated from this software can be used to “pre-qualify” a GE MRI scanner for ACR accreditation or could be used for Daily Quality Assurance (DQA) testing. The ACR-PA tool was designed to replace a very manual, tedious, and operator dependent / subjective testing procedure for acquiring and analyzing ACR phantom test data. The ACR-PA tool automates the data acquisition (scanning) and image analysis portions of the ACR phantom test procedure.
Literature research was done to search for any similar software tool set and to get historical information on the ACR MRI Accreditation Program. The ACR-PA tool was designed using OOD-UML techniques and used the rapid prototyping software development approach. The milestone accomplishments for this project were as follows: 1. Requirements Gathering and Critical to Quality parameter identifications. 2. Top-level software design using UML practices and methods. 3. Design and assembly of a prototype ACR phantom holder. 4. Design and implementation of the GUI interface and workflow. 5. Design and implementation of the data acquisition software. 6. Design and implementation of the image analysis software modules: a) Geometric Distortion Test b) High Contrast Spatial Resolution Test c) Slice Thickness Accuracy Test d) Slice Position Accuracy Test e) Image Intensity Uniformity Test f) Percent Image Ghosting Test g) Low Contrast Object Detectability Test. 7. Verification testing and data collection.
Data were collected and analyzed on a number of GE MRI systems at GE Medical Systems headquarters in Waukesha, Wisconsin and at hospitals and clinics in the local Milwaukee metro area. The data show that the ACR-PA tool is a fast and reliable method for collecting and analyzing ACR phantom image quality data. Total execution time of the ACR-PA tool is approximately 20 minutes as compared to several hours for the currently existing manual measurement method. Data generated by the ACR-PA tool were verified against independent manual testing via a formal Verification Test Plan and showed good correlation between the automated image analysis results and manual measurement techniques.
Abstract: This project addresses an existing issue in the water filtration industry regarding the installation of tube settlers in sedimentation basins. The tube settlers are commonly used during the purification process. However, the short-circuiting of, and the necessity to support, tube settlers has led to the creation of a complicated support frames system and distributor-collector infrastructure. This project was performed as a proof of concept proposed by Roberts Water Technologies to combine influent distributors and effluent collectors with a support frame for tube settles. The concept should end up as a cost-effective and easy-to-install alternative to existing tube settler structures.
The model was designed and developed with the principles of water filtration flow and structural analysis. Manufacturing options were evaluated and successfully implemented into the fabrication of the final model. Vishay Micro-Measurement rosette-type gauges and indicators were used to conduct the tests. Visual observation of the model under static load conditions was performed as well.
The results of the project proved the model is able to carry the expected loads, and to have the required flow during operation stage. It is also an easy-to-install, light-weight system. Additional hydraulic calculations or tests would be beneficial for further development of the prototype.
Abstract: Project objective: Energy conservation is an important topic in the 21th century since the energy consumption is on the rise and the natural resources are in decline. Saving energy that is normally wasted is an attractive topic. Control of the vehicle’s engine and transmission and recapturing braking energy, normally wasted, can result in improved vehicle fuel efficiencies and a cleaner environment. A normal internal combustion engine powered vehicle with a hydrostatic transmission offers the possibility to incorporate energy storage (accumulator), four-wheel-drive, and an infinitely variable transmission. While the hydrostatic transmission is known for low efficiencies due to the combined hydraulic and mechanical losses, careful computer control can lead to attractive overall fuel efficiency and lower emissions. The computer controls the engine throttle and the displacements of the engine pump and wheel pump-motors. The engine is turned on during high power driving and to recharge the accumulator which intermittently drives the vehicle and captures energy normally lost during braking.
Methodology: Objected Oriented Software, 20-Sim, is utilized to model and simulate the vehicle driving through the Federal Urban Drive Cycle (FUDC). The engine operating map, the engine pump, wheel pump-motors, and accumulators and the vehicle body are modeled. The engine pump and wheel pump-motors are modeled using Bond Graph representation. The vehicle body and the accumulator are modeled with equation models. Block diagram representation is used to represent the engine operating map and the FUDC.
Conclusions: In order to obtain the best fuel efficiency, the engine needs to be operated along the line of lowest fuel consumption. Also the engine needs to be turned off while the vehicle is stationary. The task of the internal combustion engine is to charge the accumulator and to drive the vehicle only if full power is desired. Driving the vehicle with lower system pressures leads to more than 30% fuel savings.
Abstract: This project examines the feasibility of expanding electrohydraulic slip control to Magnum tractors operating with a trailing implement. Currently, slip control is only available on Magnum tractors operating with the three point hitch option. The Electrohydraulic Draft Control (EDC) system controls hitch operation and provides the operator with position, draft, and slip control for implements mounted on the hitch. Benefits of the system include: minimized load to the tractor; constant depth for pinpoint farming; maximized horsepower utilization; and reduced operator fatigue.
Currently nine percent of Magnum tractors are sold without the hitch option. The number of these “Western Specials,” named after the region most likely to purchase them, is predicted to increase in the next five years due to an increase in the number of large corporate farms. These farms will be operating with larger, heavier implements in order to reduce the number of passes required to complete work in a field. The three point hitch will not have the capacity to operate these implements. Consequently, none of the aforementioned benefits of the EDC system will be available to this customer class. An electrohydraulic slip control system for trailing implements will preserve these benefits. Slip control is the only control scheme from the EDC system that can be transferred to trailing implements since they lack the geometry required for draft sensing and have gauge wheel stops that provide depth control.
Abstract: A database on the Web was implemented to manage defective inventory shipped to a warehouse. The database provides the desired visibility of the defects and the communication links between responsible parties for the effective management of defective inventory. Methodology used throughout this project includes numerous customer interviews, as well as organized brainstorming sessions amongst team members. A customer, in this project, is anyone who relies on the process in some way to perform his or her daily job. This methodology is used to design process flows, procedures, and custom software tools.
The technical aspects of this project are related to software engineering, industrial engineering, and engineering economics. Software engineering was used to design and create a custom Microsoft Access database on the Web, industrial engineering was used to design detailed workflows and procedures to document the process, and engineering economics was used to calculate the financial impact of the process to measure its success. The power of electronic and Internet tools (such as Microsoft Access, electronic mail, and Lotus QuickPlace) to instantaneously share data between people many miles apart was a major finding in this project. The use of such tools has drastically reduced the amount of time that defective inventory is stored at the company’s warehouse. The end result is lower inventory costs to the company.
Abstract: The purpose of this project was to reduce the weight of a domestic freight locomotive’s radiator hood, so that it could be fully assembled and loaded onto a truck for shipping without exceeding the crane capacity in the area where the structure was build. PATRAN/NASTRAN finite element analysis software was used to determine the best ways in which to reduce the weight while maintaining structural integrity. The results of the analysis were validated through sample calculations and by comparing the results to a previous analysis that was run for the original design by an outside supplier. In addition to removing material by varying the thickness and grades of steel used to make the hood structure, alternative materials like aluminum and composites were also reviewed to see if they should be incorporated in the design.
Based on the results of the analysis, the weight of the structure could not be reduced enough to fully assemble the hood before lifting it onto the truck for shipping, but could be reduced enough to lift the structure onto the truck with only a few bolt on items that still needed to be attached. This was done by using higher grades of steel and by reducing the thickness of the steel in a number of areas in the structure. It was also determined that it was not cost effective or practical to change from steel to either aluminum or composites for the majority of the structure, but the potential to use composites in portions of the structure was suggested as a means to reduce labor costs.
Abstract: In the spring of 2003, a 60-kW microturbine with heat recovery was installed at the Anderson Municipal Building in Milwaukee, Wisconsin. The heat recovery is used for building heating. The intent of the project was to take advantage of the energy efficiency of cogeneration while also providing a standby generator for the building. The equipment was heavily instrumented in order to verify efficient operation and act as a demonstration facility for the community.
The goal of this project was to produce an automatic sequence that will only dispatch the microturbine when it is financially advantageous. Real run-time data was used to determine what conditions, both outside (weather, thermal load) and inside (energy demand), resulted in cost savings, using current utility rates to credit the energy produced by the microturbine.
Currently the building can only consume both types of energy produced by the microturbine (thermal and electrical) in the winter. This project also analyzed the addition of an absorption chiller, which would absorb thermal energy in the summer.
Due to relatively high natural gas cost compared to electricity cost, the operation of the microturbine was not found to be cost effective at any time. Also, the absorption chiller was not found to be cost effective over the existing vapor-compression chiller.
Abstract: The purpose of this graduate capstone project was to design a current feedback based audio amplifier which meets a specific set of design specifications. Current feedback is a type of amplifier topology which is in contrast to voltage feedback. Current feedback has the properties of high slew rate, wide bandwidth, low distortion, and gain/bandwidth independence. Voltage feedback has limitations in those respects. The only points where current feedback is limited by comparison is in its levels of gain and stability, which are addressed in the project development.
The design of the amplifier was approached through extensive research on the subjects of current feedback topology and audio amplification. It was determined that the most important aspect of designing the amplifier is analyzing it in terms of major sections, and then further analyzing those major sections on a sub-section basis. Specific components can then be selected and incorporated into a basic, but essential circuit layout. Iterative testing and design alteration then allows the circuit performance to be developed.
Testing of the amplifier circuit in simulation (Multisim) provided several key results. The specified bandwidth, total harmonic distortion, and signal-to-noise ratio were achieved, but the slew rate, closed-loop gain, and RMS power output fell short. It is believed that these shortcomings were due to the way frequency compensation was implemented, and is discussed further in detail in this report.
Abstract: The research presented in this paper provides a thorough analysis of a technique that standardizes and justifies the cost process for fabricating a part in the rapid prototyping (RP) industry. Stereolithography (SLA) and Selective Laser Sintering (SLS) are the focus of the study because they are the two most commonly used RP technologies. The techniques are applied to the SLA-250/50 and the Sinterstation 2000 systems located in the Rapid Prototyping Center (RPC) at the Milwaukee School of Engineering (MSOE).
The study incorporates all the cost variables associated with operating each RP machine. It also evaluates these variables based on hours of complete build time. Finally, it includes accurate build time estimation and premium factors for each machine, which are vital for determining the final cost of a prototype.
The rapid prototyping industry has not adopted a standard method for projecting the cost of a prototype. The innovative industry is affected by the nonexistent standards, which make the process of estimating cost quotes very difficult and unclear. Some commercial RP providers attribute build time for cost, while others use complex algorithms to determine their cost. Ultimately, there is no right or wrong method but obviously something is missing.
Abstract: The purpose of this project is to create a computer program to simplify the design and analysis of concrete-filled metal-pan stairs. In addition to the stress and deflection of each member, the program calculates the amount of welding required at each joint of the stair to make a proper connection. The program should help standardize the design and reduce the cost of stairs by providing a consistent analysis, proper member and weld sizes, and by reducing the drafting time required by determining the layout dimensions of the stair. The stair program is written in code for Matlab.
The scope of the project and computer program is limited to a straight stair that is rigidly supported at both ends with no intermediate supports or landings. Inputs into the program include the stair loadings, material properties, and a minimum number of dimensions to define the components of the stair.
The effects of the concrete were ignored for the stair analysis due to the uncertainty of the concrete properties, the purpose of the concrete, and the manufacturer of the stair bearing the majority of the responsibility of providing a structurally sound stair. The stair was analyzed by breaking the stair into three major components: the stringer, the riser, and the tread. Equations were then determined to separately calculate the stress and deflection of each component of the stair for a uniform and concentrated load. The required weld for the connection of the riser to the stringer and the connection between the stair pans was determined by analyzing the weld as a line with no area. A comparison of the Matlab program results to the FEA results indicates that the results strongly agree with each other over a wide range of input values for both the uniform and concentrated loads.
Abstract: The purpose of this project was to develop a hydraulic control system for a regenerative hydraulic assisted turbocharger (RHAT) system. The RHAT system consists of a hydraulic pump and turbine mounted on a turbocharger shaft between the exhaust driven turbine and intake compressor, an accumulator, and oil control valve. The hydraulic turbine provides supplemental power at low exhaust energy levels to reduce turbocharger lag during acceleration events. During engine breaking, the hydraulic pump sends oil into an accumulator to store the hydraulic energy. The regenerative aspect is what makes this technology unique over previous hydraulic assisted turbocharger designs.
The main focus of this project was to build a one-dimensional simulation model for a medium duty diesel truck engine, including the RHAT system, and oil control valve. It was necessary to characterize the valve through experimental testing and then complete a magnetic FEA model of the solenoid and a CFD model of the poppet to generate the look-up tables for the simulation model. Once the simulation models were verified, they were incorporated into the engine model to demonstrate the performance improvements.
The results from the engine model showed approximately 30% faster turbocharger response and engine response. The model also showed that a regeneration cycle was sufficient to recharge the accumulator after a discharge cycle.
Abstract: The purpose of this MSE Capstone Project is to prevent further damage to the lower back by educating the user about everyday hazards. Thus improving that person’s quality of life since occupational health and sports injuries have an expanding impact so a wiser or more informed community is needed.
The process was to define the parameters of the intervertebral disc, run the analysis of the force, compare the results and then formulate the mathematical equation that represents the compressive force acted upon the L5/S1 disc. The activities tested were standing, sitting, lifting with and without twisting at various weights and heights. Since body weight is a factor, the Body Mass Index (BMI) is calculated and then its respective body strength is computed to determine the offset of the force from the object moved. This allows for a full range of forces evaluated for each unique person. These activities are further defined in the parameters table. It is assumed that the user is a healthy person that has correct posture and the load weight is uniform. This makes the spine and the ground perpendicular to each other.
After checking the compressive forces calculated from the individual standing, sitting, and lifting with and without twisting, the force formula was within two percent of the results from the proven lifting equations such as NIOSH and the Manual Lifting Task equations. The maximum force was evaluated by the upper limit of 45° for twisting, 60° for bending, 30 kilograms for the object’s weight and a BMI of 35. The average height of Americans of 168 centimeters was collected via the census over a 40 year period.
Abstract: The purpose of this Master of Science in Engineering (MSE) Capstone Project was to design a flexible, extendable, and robust software-based Fuzzy Logic Engine (FLE) using the Unified Modeling Language (UML) to communicate the design and software design patterns as a basis for an object-oriented design. The design features included: Interfacing with any input/output subsystem used as data-sources or data-sinks, capturing system events and statistical information for debugging and analysis, describing fuzzy logic system models using a simple grammar and text files, and offering easily interchangeable algorithms, like defuzzification algorithms.
The design utilized the Composite design pattern when parent-child hierarchies were needed, while an Observer-like pattern applied to a notification subsystem automatically communicating data and events between objects. The Builder and Visitor patterns were utilized in converting user-defined fuzzy logic system models into executable software objects, while the Strategy pattern was applied to make families of interchangeable algorithms. Finally, the Facade design pattern was utilized to provide a simple, single, public interface for clients, thus hiding the subsystem details.
The technical, mathematical understandings of fuzzy logic theory were replaced with simpler, graphical understandings to communicate design information to implementers lacking a detailed background in fuzzy logic theory. Furthermore, the report discusses a functional prototype successfully demonstrating a simplified implementation of the notification subsystem lending confidence in aspects of the design. The purpose of this Master of Science in Engineering (MSE) Capstone Project was to design a flexible, extendable, and robust software-based Fuzzy Logic Engine (FLE) using the Unified Modeling Language (UML) to communicate the design and software design patterns as a basis for an object-oriented design. The design features included: Interfacing with any input/output subsystem used as data-sources or data-sinks, capturing system events and statistical information for debugging and analysis, describing fuzzy logic system models using a simple grammar and text files, and offering easily interchangeable algorithms, like defuzzification algorithms.
Abstract: The purpose of this document is to describe a capstone project for the Milwaukee School of Engineering’s (MSOE) Master of Science in Engineering program. The goal of this project was to produce a thermal modeling technique for high-power, high-frequency transformers, such as those used in gradient driver power supplies for Magnetic Resonance Imaging (MRI) scanners.
Analysis tools such as computational fluid dynamics (CFD), and finite element analysis (FEA) were used to develop both a three-dimensional steady-state thermal model as well as a two-dimensional thermal model, which was used to tune the three-dimensional model. Optimization techniques were used to fit the two-dimensional model to the three-dimensional model. Thermal measurement data were collected from physical transformers and used to tune the model parameters and verify the validity of the modeling technique. It was determined that the measurement techniques employed were susceptible to noise and require further study. In addition, it was determined that the input assumption of transformer losses may have been incorrect and requires more understanding. The value of this modeling technique is to allow the design engineer to predict the thermal margin on a given transformer design, which ultimately will drive the reliability of the product. If the inputs are correct, then this technique should be able to achieve that goal.
Abstract: The Falk 405 ABRCM gearbox was designed to save the customer time and money. The customer would not have to set up a foundation for the gearbox and also the customer would not have to frequently align couplings.
The purpose of the torque-arm is to support the gearbox assembly and give the required five degrees of freedom to the system. Torque-arm misalignment has been proven to cause low-speed shaft failures and torque-arm pin failures. Redesigning the torque-arm assembly would allow for correction of torque-arm misalignment errors without equipment modification.
The criteria used for selection of the new assembly were as follows: first, alignment correction in the radial direction (30 degrees) and Z-direction (10 degrees); second, stronger torque-arm pins were required because of the pin failures that have occurred. Calculations were performed to determine the possible loads applied to the torque-arm. The loads were then used to determine stresses so each component could be sized and designed properly.
The new torque-arm assembly consists of a two-piece mounting bracket for alignment correction. The torque-arm was changed from a single piece design to a two-piece rod end assembly. The two-piece rod-end assembly allows for easy lubrication and for a larger and stronger pin design.
Abstract: Objective: An ambulatory electrocardiograph, better known as a Holter recorder, is a powerful tool in fighting heart disease. A Holter recorder provides long term monitoring of the electrical activity of the heart, helping physicians treat heart disease. Advances in integrated circuitry and inexpensive memory cards present an opportunity to design a low cost Holter recorder. The objective of this project is to design, build, and test software and hardware for a low cost Holter recorder.
Methodology: A specifications list was generated that meets the requirements of long term ECG monitoring. The specifications reflect the “Ambulatory electrocardiograph” standard developed by the Association for the Advancement of Medical Instrumentation (AAMI). The Holter recorder design was broken down into modules to simplify the design process. Each module was developed independently and then integrated to complete the design. Design alternatives were selected based on how well they met design specifications.
Major Findings: The prototype Holter recorder was constructed and tested against the specifications list and was found to meet all its design goals with the exception of the compression ratio specification. The project has shown that a low cost Holter recorder is possible. The use of a high integration microcontroller was the major contributor in the achievement of this goal. The microcontroller reduced part count, size, power consumption, cost, and greatly simplified the design.
Abstract: To make electrical or electrohydraulic gas exchange valve actuators more economically feasible for the production of camless engines, it is desirable to achieve valve position information from existing engine sensors. Time and frequency domain characteristics of sensor signals were analyzed using both cross-correlation and Fourier analyses to determine characteristics that indicate valve position.
The time-domain signatures for valve events were found to be inconsistent from cycle to cycle and thus difficult to identify using cross-correlation techniques. Frequency content of the engine vibration as it varied with crankshaft angle was analyzed to find valve position dependent patterns. Analysis revealed a wideband signal that correlated to intake and exhaust valve closure. A variety of filtering schemes were implemented in an attempt to maximize the coherence of the valve close signal. It was found that the best signal is contained in the 50 kHz component — which is the resonant frequency of the sensor. A narrow bandpass filter centered at this frequency provides a good means of valve closure detection using a reasonable number of engine cycles. This was determined for a specific knock sensor. The spectral effects of various knock sensors are illustrated to show the dependence on sensor characteristics in valve event detection.
The manifold-air-pressure (MAP) sensor and the mass-air-flow (MAF) sensor signals were investigated for correlations to intake valve open and intake valve close. No correlations were found in this investigation for the particular engine and sensors studied.
Abstract: Objective: The Teflon coated, machined brass, piston is one of the most critical components in Pentair Water Treatment’s water softener and filter control valves. It is also one of the most costly to manufacture. The objective of this project is to identify all the important properties and requirements the piston must meet, research alternative materials and processes that meet those requirements, and identify which might be less costly to procure and manufacture.
Methodology: A design checklist was created, which specifies the critical characteristics of the valve piston. The list defines physical, mechanical, environmental, and regulatory agency requirements. These specifications are guidelines for searching for alternate materials and manufacturing methods. Initial material research was done utilizing the Internet, Pentair’s component suppliers, and material suppliers. Manufacturing methods available for different material choices will also be researched using the same resources. Material choices were narrowed down to those that best fit the critical characteristics. Manufactured costs were estimated. Finally, prototype pistons are to be made of materials, and functional testing conducted to evaluate performance.
Major Findings: The best candidate materials are thermoplastics, which offered the widest range of material properties, economical cost, and more than one economical manufacturing method. The manufacturing method best fitting the requirements is machining.
Abstract: Objective: The objective of this project is to design and build a portable pulse rate meter. The device will be used to measure a person’s heart rate while at rest or during exercise. A prototype device will utilize low cost components and the circuitry will be fabricated on a printed circuit board. The device will use a non-invasive measuring technique using a finger probe.
Methodology: The pulse rate meter will be designed in hardware and software. The device is designed to meet the documented project specifications. The hardware modules include a power supply, detection circuit, high-pass filter, signal low-pass filter, reference low-pass filter, signal phase delay, comparator, microcontroller, and output device circuits. The software modules include a Main Routing and an Interrupt Service Routing. A verification section documents the design’s performance to the given specifications.
Major findings: The prototype pulse meter designed in this project met all product specifications. This project proved a low cost portable pulse rate meter could be designed. The hardware signal filtering created a signal a microcontroller could analyze and calculate a pulse rate. Utilizing the microcontroller’s peripherals allowed the design to be highly integrated at low cost and small size.
Abstract: The purpose of this report is twofold. The first is to partially fulfill the requirements for the degree of Master of Science in Engineering at the Milwaukee School of Engineering. The secondary purpose is to educate the reader in the topic of design automation in the field of Solid Modeling and Computer Aided Engineering. The method used to achieve this purpose is to develop the steps necessary to automate the design of a marine propeller based on its fundamental features. These steps include: 1) The development of a Graphical User Interface (GUI) used to gather the design intent from the propeller design. 2) The modeling of a marine propeller in solid modeling software whose design is robust enough to be modified into numerous various shapes. 3) The development of the interface software to be used to enable the user to control the propeller solid model with the GUI. The methods used to automate this design include the use of three main tools. 1) Microsoft Visual C++ MFC programming tools are used to develop the GUI. 2) Parametric Technologies Corporation’s (PTC) solid modeling package Pro/ENGINEER is used to develop the propeller solid model. 3) PTC’s Pro/TOOLKIT is used in conjunction with Visual C++ to develop the interface software. Pro/TOOLKIT is a collection of C function calls used to control the Pro/ENGINEER environment.
It was concluded that a propeller designer, using the tools and methods described in this report, can successfully automate the design of a marine propeller, cutting time and money out of the engineering process.
Abstract: This project involves the modeling, design, and analysis of a heat exchanger system using the concepts of conduction, convection, thermal capacitance, conservation of energy, and numerical techniques. In this work, the heat transfer process for the heat exchanger roll system is analyzed in one dimension based on the “simplified transient conduction into a semi-infinite medium model.” Numerical techniques are used to develop and construct a software program with a graphical user interface (GUI). Using Visual Basic (version 6.0), the developed software program calculates the temperatures, the direction of heat transfer, and internal fluid flow rates. The end-user first needs to specify the required numerical inputs based on the application in order to properly perform a heat transfer analysis.
This paper discusses the testing apparatus, its significance in gathering accurate temperature data, and how the experimental temperature was obtained. It also details the high correlation that exists between the simulated predictions with the experimental trials replicating real web converting conditions. Finally, this work concludes with recommendations for future work.
This main purpose of this project was to assist the roll manufacturer in heat exchanger roll quoting, analysis, and design. The overall software simulation viability as it is developed will depend on how the roll manufacturer markets this information to the web converting industry.
Abstract: Structural analysis of mechanisms with components that move relative to each other provide a unique problem to the analyst building and running structural models. In these situations, the analyst usually has to either simplify the problem to a point where the results are unusable or maintain multiple models, which will take more effort to maintain and more resources to run the models. If a mechanism is simplified down to just analyzing one component at a time without regard for the other components in the system, the results will not be accurate because the loading effects of the other components will not be accounted for. In cases where all the components are included in the model, the loading effects from the other components will be accounted for; however, a separate model will be required for each position. The Pivot Method presented in this paper is a method of breaking down a complex mechanism into component-level models for each part of the assembly, while still accounting for all loading effects of the other components. In the Pivot Method the component under analysis stays stationary and the loading moves around the component to represent the different positions that it can take.
In order to accomplish this task, a stick model is used to generate loads at each of the joints. Once the pivot loads are known a spreadsheet can be used to transform the loads to a coordinate system in which the individual component is being modeled. With the pivot loads known and all the loads transformed into the proper coordinate system the structural analysis of the component under investigation can continue.
The intention of this paper is to introduce the Pivot Method, and demonstrate that it provides a good trade off between the complexity of methods that model the assembly as a system, and those that focus on the component under question by itself. To accomplish this, the analysis results of the Pivot Method models were compared to results obtained from other methods. The findings indicate that the Pivot Method provides the same results while requiring less effort to model and fewer resources to run. The Pivot Method provides the same stress results as the more complicated methods, while not requiring any more resources to run than simpler methods. Additionally, the Pivot Method is much simpler set up and maintain the models than the more complex methods.
Abstract: The purpose of this project was to develop a method that can be standardized across the Computed Tomography (CT) modality within GE Healthcare to confidently design for fatigue to a 30 year service life rather than infinite life. Different modeling and analysis approaches were investigated to determine the best solution for integrating design for fatigue into CT product development. For this investigation, these modeling and analysis approaches were implemented on sheet metal parts and a machined CT part. Testing was completed to verify these models and adjustments were made. Based on the data found, a method for modeling and testing CT fatigue for 30 years of service life has been developed. This method includes component design considerations as well as fatigue analysis and testing. It is recommended that the CT Modality use all three of these together when designing for fatigue to ensure a reliable design.
Abstract: The intent of this work is to investigate the economic feasibility of a small robust batch processing system to reduce dependence on foreign oils by South Pacific islands.
A robust biodiesel production system was conceptualized. The components of the system were sized to consume 200 liters of coconut oil and 85 liters of ethanol to produce 270 liters of biodiesel and 25 liters of glycerin per batch. Using an Excel spread sheet, the present values of costs and benefits were compared concerning the production of biodiesel versus the option of continuing to purchase diesel fuel.
In almost all long term economic circumstances the proposed system to produce biodiesel is the favored solution. During the first few years of biodiesel production, as the initial equipment costs are being amortized, the net present worth of doing nothing and purchasing diesel fuel will be lower. However, once the initial equipment costs are paid for, significant savings can be realized by using the proposed biodiesel production system.
Abstract: The objective of this capstone project was to develop a model which defines the flow distribution of the coolant in the General Electric (GE) Magnetic Resonance (MR) heat exchanger cabinet (HEC). This cabinet is essential in the cooling of the system’s power electronics. The approach described in this paper utilized Flow Network Modeling (FNM) to analyze the system both quickly and accurately.
The capstone presents the use of FNM, as proposed by G. Ellison, to perform a first order thermal analysis on MR liquid cooled power electronics. Ellison’s method is used to predict system level pressure drops and coolant flow rates through power electronic cold plates in order to ensure adequate heat transfer occurs in the system. The impedance characteristics were calculated based on known relationships available in many handbooks. The analysis demonstrated the interaction of the pump curve and the flow impedances in order to predict the flow distribution of coolant throughout the entire system.
Overall, a sustainable flow network model was created in Excel that describes and predicts the behavior of the MR cooling system. Results of the Ellison-based approach were compared to data taken from engineering bays with the same system configurations. Comparison of the two data sets shows that the results agree to within 15% of the measured data. Thus, the use of FNM as an aid in developing thermally feasible MR cooling systems is validated. The use of additional measured data could help to refine the model and to increase its accuracy. Therefore, this report recommends the use of the model – along with other methods such as Computational Fluid Dynamics – for the redesign and layout of a next-generation MR cooling system.
Abstract: My project is to upgrade a forty-five year-old manually operated 15,000-ton hydraulic press equipped with a single manually operated joystick controller driving hydraulic valves. The current manual operation has limited repeatability, low reliability, and will not meet customer requirements for ISO 9000 certification.
This project adds both semi-automatic and automatic modes of operation using a Programmable Logic Controller (PLC), a Man Machine Interface (MMI) and an industrial computer. A database containing parameters such as position, velocity, and pressure is created. These parameters are monitored, controlled, and recorded at preset sampling rates through Supervisory Control and Data Acquisition (SCADA) systems via a Data Highway Plus (DH+) communication network on an industrial PC. The PC also is equipped with a network card for transferring database files to a business system at periodic intervals. The MMI allows the operator to easily and accurately set up the system and provides a visual indication of the operation.
The equipment controlled, in addition to the press, includes a hydraulic fluid power source that is equipped with (4) 300 hp, 100 gal/min Worthington pump motors (piston driven), and a 900 hp, 300 gal/min Aldrich pump for higher volumes. These pumps supply water with chemical lubricant to (2) 37 ft long, 5 ft in diameter accumulator bottles, which are level and pressure controlled at 1,650 gallons and 4,600 psi by the PLC via DH+.
Abstract: The purpose of this project is to develop an instrument that is able to evaluate the functionality of sensors used at MGA Research Corporation. This functionality test references calibration values stored in a database located on a company server by use of a silicon serial number. Once the testing routine is complete the device compares the values measured with the reference values drawn from the database. The data are displayed to the user in an easily understandable format.
This instrument required both hardware, embedded software, and a graphical user interface program to be designed to meet the product specifications. The hardware modules include a power supply block, an array of multiplexors, a microcontroller, a USB to 1-Wire interface, and a host computer. The embedded software module designed handles the communication structure between the host computer and the analog-to-digital converter system on a chip. The embedded software also controls the multiplexor array through its general purpose input output ports. The graphical user interface draws information from the database as well as controls the tests conducted and relays the collected information to the user.
A fault evaluation test circuit was used to evaluate the sensor analyzer. It was found that the prototype sensor analyzer designed and fabricated for this project meets all of the product specifications. The sensor analyzer could detect the most common sensor failures found at MGA Research Corporation.
Abstract: The primary purpose of this investigation was to get a deeper understanding of FPGA hardware description languages and to apply that knowledge in a product that has practical applications. After some investigating, the hardware description language that would be used for the product would be Verilog. The product that would be used to demonstrate the application of the Verilog hardware description language is a portable generator, which has the means of controlling the engine speed and the frequency from the alternator.
Once the language was chosen, a block diagram was made of the various programs to determine the flow of logic signals. Then within each block, another block diagram was created to show the flow of logic signals. From this level, a program was created for each block. Then the blocks were connected to each other. Finally, the LED’s on the prototyping circuit board along with other test equipment such as an oscilloscope were used for troubleshooting to ensure proper operation of the programs.
From this investigation, it has been learned that the FPGA hardware description languages do not have some of the easy debugging tools found in other programming languages such as “C”. This made the troubleshooting process more challenging and time consuming. On the other hand, this technology demonstrated how flexible and powerful it could be. As an example, the program can be designed using written code, individual logic symbols, complete computer chip symbols or a mixture of all three.
Abstract: Objective: This project created a simulator to functionally test the uterine activity portion of a perinatal monitor, a medical device used to monitor patients in hospital labor and delivery. The simulator is used to present uterine pressure signals to the medical device during automated manufacturing test.
Methodology: Medical device and manufacturing specifications were gathered to determine the electrical hardware requirements and the manufacturing tests to be used to exercise all of the uterine activity related medical device functionality.
Major findings: A simulator can be used to accurately test the functionality of the uterine activity channel of the medical device in the automated manufacturing environment. The design limits of the perinatal medical device can be tested by means of applying static stimuli. A dynamic simulation of the actual human labor event is therefore, unnecessary.
Abstract: The objective of this project was to determine the validity of using MRI (magnetic resonance imaging) data to identify abnormalities in human airways and to analyze the internal flow behavior, which is conducted by means of fluid flow analysis. CT (computed tomography) scans have long been used to develop three-dimensional (3D) models of internal anatomy because of their fine resolution and contrast between tissue densities. The negative aspect of these scans is that they expose patients to medical risks because of the radiation that is emitted when capturing the images. Because of these risks, MRIs are considered to be a safer imaging option; however, their image quality isn’t as fine. The original goals of this project were to employ static (standard) and dynamic (cine) MRI images from pediatric patients to develop accurate models of their airways, and to use the models to perform computational fluid dynamics (CFD) simulations. CFD simulations results would then be used to identify areas of large pressure differentials and air recirculation, which could indicate areas of concern. These results would then aid medical personnel in determining which medical procedures could be performed to minimize irregular or problematic air flow. Because of time constraints and challenges associated with the MRI images, the project goals were refined. Standard and cine MRI data from a single patient, and CT data from an additional patient, were employed in an attempt to establish a technique for developing accurate 3D fluid domain models from MRI data. This report explains the work performed during the two-phase project. The first phase of the project focused on the generation of 3D models from cine MRI data, and the second phase focused on use of the models in CFD simulation. To generate models from standard MRI data in their original DICOM format, a complicated series of data manipulation techniques was necessary. Using 3D Slicer, along with thresholding and image segmentation, a 3D mesh model was extracted and created. The mesh model was refined and converted to a STL format with a number of tools, including, Blender, Meshmixed, and Remake. Fusion 360 was employed to convert this model into a solid model needed for simulation. The solid model was imported into ANSYS Fluent, where the mesh was optimized for simulation, and laminar and turbulent flow simulations were successfully conducted. An attempt was made to employ cine MRI data to analyze the changing geometry of the airway. Difficulties were encountered in working with the cine MRI data, because they had to be analyzed manually. A recommendation for future research is the development of a software program that can automate the analysis of cine MRI data. CFD simulations of the MRI data revealed recirculation within the airway, but no other areas of concern were discerned. The project was successful in verifying that 3D models suitable for simulation can be extracted from MRI data.