MEMORANDUM - University of Idaho



MEMORANDUM

Date: 4 May 2006

To: Office of Naval Research

Dr. Dean Edwards

From: Team Assault and Battery

Linnea Anderson

Matt Braley

Chad Schierman

Daniel George

Slade Klien

Matt Shaw

Bryan Blakey

Albert Whetstone

Subject: Hybrid Electric-HMMWV

We submit the accompanying report entitled “Office of Naval Research Hybrid

Electric-HMMWV: Platform for Advanced Battery Testing.”

This paper reports on the state of the Hybrid Electric-HMMWV project. It describes the theory of the system and the capabilities of possible configurations. It explains the pieces of hardware and software the project group has developed, and recaps the outcomes of the system design. The paper then offers recommendations to future project teams for additions to the HMMWV and ideas for future projects.

We would like to thank Dean Edward’s advanced lead-acid battery research group and the Office of Naval Research for putting so much money, time and labor into this project. We believe that Team Assault and Battery has developed a very useful and profitable project.

If you would like any additional information please see our team website: . There will be additional information included on a CD which will be submitted in conjunction with this report. This CD will include the following information: wiring diagrams, mechanical drawings, team developed code, the DFMEA, HMMWV technical documentation, instruction manuals, product manuals and other design documentation that was consulted as we completed the following design. We look forward to your feedback. Please use the team e-mail aandb@uidaho.edu to contact the team with your response to this report.

Assault and Battery Team University of Idaho

Chad Schierman Linnea Anderson Bryan Blakey Matt Shaw CAPSTONE Senior Design

Danny George Slade Klein Matt Braley Albert Whetstone Fall 2005- Spring 2006



aandb@uidaho.edu

Office of Naval Research Hybrid Electric-HMMWV:

Platform for Advanced Battery Testing

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Prepared for

Office of Naval Research

Dr. Dean Edwards

University of Idaho

Prepared by

Team Assault and Battery

CAPSTONE Senior Design

University of Idaho

Instructors

Dr. Herbert Hess

Dr. Steven Beyerlein

Brice Quirl

Dan Cordon

May 4, 2006

Abstract

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The following report is a description of the design of a hybrid electric HMMWV (High-Mobility Multipurpose Wheeled Vehicle). This hybrid electric vehicle was commissioned by the Office of Naval Research with the intention of testing advanced lead acid batteries. To be a good test bed for the batteries, the following needs must be met: 1) the HMMWV must be returned to functional condition as a hybrid electric vehicle, 2) the battery bus must be unified to 360V DC, 3) a thermal management system must be designed to keep the batteries at optimal operational conditions, and 4) the battery and vehicle operational characteristics must be monitored and displayed. We will lay out the characteristics of our design, the subsystems that comprise that design, the integration of these subsystems into the final design, and show how this design meets the above needs in the following report. We will also discuss the economic impact of the project and make recommendations for the future stages of the project.

Table of Contents

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Abstract ii

Table of Contents iii

List of Tables and Figures iv

1 PROJECT OVERVIEW 1

2 PROJECT DEFINITION 3

2.1 Needs of the Project 3

2.2 Project Deliverables 4

2.3 Design Constraints 4

3 CONCEPTUAL DESIGN AND COMPONENT SELECTION 4

3.1 Volkswagen Turbo-Diesel Engine and UQM Motor 7

3.2 AC Propulsion 150 KW Generation II® Propulsion Unit 9

3.3 AC Propulsion Electric Drive Motor and Planetary Gear Reducer 10

3.3.1 Gear Reduction Calculation 10

3.3.2 Motor Mounting Design 12

3.4 Control and Data Acquisition System 14

3.4.1 System Control 15

3.4.2 Data Acquisition 15

3.5 Battery Enclosure and Battery Pack 16

3.5.1 Battery Enclosure Placement 16

3.5.2 Surrogate Batteries 17

3.6 Thermal Management Design 18

3.7 DC to DC Converters 19

4 SYSTEM INTEGRATION 20

4.1 Power Interconnections 20

4.2 Data Acquisition Interconnections 22

4.3 Control Interconnections 23

4.4 User Interface 24

5 PRODUCT EVALUATION 27

5.1 Self Propelled Vehicle 27

5.2 Battery Thermal Management System 27

5.3 Data Acquisition System 28

5.4 Unified Battery Bus 28

5.5 Design Failure Modes and Effects Analysis 28

6 ECONOMIC ANALYSIS 29

7 FUTURE RECOMMENDATIONS 31

7.1 Generator and Engine Incorporation 32

7.2 Performance Characteristics of Hybrid-Electric HMMWV 32

7.3 4 Wheel Drive Capability 33

7.4 Updated Battery Enclosure 33

7.5 Forced Air Heating of the Battery Enclosure 34

7.6 AC Propulsion Battery Monitoring System 34

7.7 Ground Fault Interruption System 35

7.8 Optimized Data Acquisition Code 35

7.9 Improved Driver Interface 35

7.10 Portable Generation Unit 35

7.11 Charge Monitoring and Current Shunting Capability 36

7.12 Bio-Diesel Incorporation 36

7.13 Self Sufficient Control System 36

APPENDIX A: SYSTEM WIRING DIAGRAMS A

APPENDIX B: MECHANICAL DRAWING PACKAGES B

APPENDIX C: INSTRUCTION AND REPAIR MANUALS C

APPENDIX D: DESIGN FAILURE MODES EFFECTS ANALYSIS D

List of Tables and Figures

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Figure 1: System Layout Block Diagram 5

Figure 2: Vehicle Location Block Diagram 6

Figure 3: UQM Engine Controller 7

Figure 4: Power Plant 8

Figure 5: Starting Circuit 9

Table 1: Characteristics of the AC Propulsion 150KW Propulsion Unit 9

Figure 6: AC Propulsion 150KW Propulsion Unit 10

Figure 7: Planetary Gear Reducer 11

Figure 8: Simulated HMMWV Response with One Propulsion Unit 12

Figure 9: Motor Mounting 13

Figure 10: Components Developed for the Final Mounting Design 14

Figure 11: National Instruments PXI-Based Chassis System 15

Figure 12: Original Battery Enclosure Design - Under Vehicle 17

Figure 13: Final Battery Enclosure Design – On Bed 17

Figure 14: Surrogate Batteries 18

Figure 15: Fans Purchased for the Thermal Management System 19

Table 2: Characteristics of Battery Enclosure Fans 19

Figure 16: Vicor Vipac DC/DC Converter 20

Table 3: Characteristics of Vipac DC/DC Converters 20

Figure 17: LabVIEW Code Screen Shot 25

Figure 18: Go/No-Go Mode for User Interface 26

Figure 19: Graphical Mode for User Interface 26

Table 4: Detailed Budget by Item 30

Table 5: Engineering Time Cost Summary 31

PROJECT OVERVIEW

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The Hybrid Electric Vehicle project is a government-funded, multi-year project. The purpose of the first stage of the Hybrid Electric Vehicle project is to transform a military HMMWV (High-Mobility Multipurpose Wheeled Vehicle) into a hybrid electric vehicle. Concurrent Technology Corporation (CTC) previously converted the vehicle that Team Assault and Battery received from the military into a hybrid electric vehicle. Originally, we thought that we might be able to return the hybrid system developed by CTC to working condition. This would have allowed us to concentrate our engineering efforts on improvements to the hybrid platform. However, after taking inventory of the state of HMMWV upon arrival, the team decided that it would be much easier to redesign the system than try to salvage the hybrid system that was already in place. The decision to design our own system was made for the following reasons: 1) half of the electrical boxes in the original system were filled with water, and the components were ruined; 2) the only wires labeled in the vehicle were the wires that came standard in the factory model; and 3) there was no documentation available from CTC for the HMMWV. All of the design documentation that follows is the team’s design.

To convert a standard diesel vehicle into a series hybrid vehicle, the drive train of the vehicle will have to be redesigned to include a battery pack, a propulsion system, and an electric motor. After these systems are included, a generator will be used with the smaller VW diesel to charge the battery pack. This battery pack will then supply power to the electric propulsion unit. The propulsion unit will interoperate the control signals from the brake and acceleration pedals and in turn supply power to the electric motor. Finally, the electric motor will turn the electric power to mechanical energy and drive the rear axle of the vehicle, providing propulsion.

Another main design decision that must be addressed by the first stage of the project is the enclosure for the battery pack. This battery pack will be comprised of 30 12V DC batteries and will be dangerous if left exposed. Therefore, a strong and secure battery enclosure is necessary. Also, it has been proven that batteries charge and discharge more efficiently in temperatures ranging from 80-120°F. Batteries operating within this temperature range also tend to have longer battery life. Therefore, a temperature regulation system must be implemented to keep the battery enclosure within this temperature range for the best operation of the battery pack.

The main goal of the first stage of the Hybrid Electric Vehicle project is to provide an environment for battery testing. By converting the HMMWV into a hybrid electric vehicle, we are creating an environment that demands large power draw from the battery pack and also is continuously charging the batteries. This makes the hybrid electric vehicle an ideal testing platform for new batteries. If a new battery will fail it will be due to extended charging and large power demands placed on it. Dr. Dean Edward’s research group is in the process of developing a power dense lead-acid battery for the Office of Naval Research. It was our goal to design the hybrid HMMWV to provide the best platform for battery testing.

To facilitate the battery testing, we designed a data acquisition and control system. The control system will be in charge of controlling the thermal management system, as well as overseeing the interaction between the propulsion unit and the driver of the vehicle. The data acquisition system will compile data on the voltages of 1) the individual batteries in the pack, 2) the high voltage of the terminals of the battery pack, 3) the temperature at each of the batteries in the pack, and 4) several other temperatures throughout the battery pack. While the vehicle is operational, this data will be displayed in the passenger compartment of the vehicle on a touch screen to aid the researchers in characterizing the batteries’ performance. All of the data collected will also be available to download to a personal computer when the vehicle is parked.

Some possible future work opportunities for future stages of the Hybrid Electric HMMWV project are as follows: 1) stock performance characteristics of the HE-HMMWV, 2) 4 wheel drive capability, 3) update battery enclosure for Dr. Edward’s advanced batteries, 4) forced air heating of the battery enclosure, 5) integration of the AC Propulsion Battery Monitoring System, 6) integration of the Bender GFI system, 7) optimize data acquisition code , 8) improve driver interface, 9) explore the use of the HMMWV as a portable generation unit, 10) develop charge monitoring and current shunting systems for the battery pack, 11) explore the use of Bio-diesel in the generator of the HMMWV, and 12) movement of the control system to a self sufficient system without data acquisition. This report will be concerned with only the first stage of the Hybrid Electric HMMWV project.

In the following project report, we will discuss the needs of the project, the project deliverables and the design constraints for the first stage of the project. Then we will outline the system that we designed along with the process we used for conceptual design and product selection. We will explore the way that the systems are interconnected to produce the hybrid electric HMMWV. We will validate our final design by showing that it meets all of the project needs. Also, we will lay out the budget for our project and where it was spent. Finally, we will recommend design projects that we would like to see implemented in future stages of the Hybrid Electric Vehicle Project.

PROJECT DEFINITION

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There are three different lists which will help us to judge how successful the final implementation of the hybrid electric HMMWV was: 1) the needs of the project, 2) the project deliverables, and 3) the design constraints. All of these lists were set by our customer and are requirements for our final design. The most important list to complete is the needs of the project. The needs of the project define the tangible results of the project; and, to prove our final result, we will have to show that the needs of the project were met. This is shown in Section 5 of this report. The project deliverables are the individual designs that will have to be completed by the team to realize the needs of the project. Finally, the design constraints are general requirements of lesser importance that we wanted to incorporate in our design, either for our stage of the project, or in the plan for future stages of the project.

1 Needs of the Project

1. Return the HMMWV to functional condition as a hybrid electric vehicle.

2. Unify the main battery bus to 360V DC.

3. Design a thermal-management solution.

4. Monitor and display battery and vehicle operational characteristics.

2 Project Deliverables

1. Integrate the diesel generator into the drive train for recharging the battery pack.

2. Incorporate an electric propulsion system into the diesel HMMWV.

3. Design and build a battery enclosure.

4. Implement a thermal management system to keep the temperature in the battery enclosure between 80-120°F.

5. Design and implement a data acquisition system that can be used to collect, display, and store the temperatures and voltages of the batteries while they are in use.

3 Design Constraints

The Hybrid Electric HMMWV must conform to the following constraints:

1. The battery status monitoring system must take data from the batteries in real time.

2. The battery status monitoring system must store the data collected from the batteries during operation for later retrieval by researchers.

3. The battery enclosure temperature must be maintained between 80˚F and 120˚F.

4. The batteries must supply power on a unified 360V DC bus.

5. All systems must fit on the vehicle.

CONCEPTUAL DESIGN AND COMPONENT SELECTION

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The hybrid electric HMMWV is physically comprised of the following components:

1. A power plant that has an engine, generator, and inverter.

2. The AC Propulsion 150 KW Generation II® Propulsion unit.

3. An AC Propulsion electric drive motor and planetary gear reducer.

4. A National Instruments PXI-based Chassis system.

5. The battery pack and enclosure.

6. The thermal management hardware located in the battery enclosure.

7. Two DC/DC converters that supply power to the auxiliary systems.

A generalized diagram of the system is shown in Figure 1. Circles on the block diagram indicate the motors. Blocks in the diagram indicate the physical components of the system. The power flow of the system is indicated with the grey arrows. This block diagram displays the series configuration of the Hybrid Electric HMMWV. The power in this system travels from the power plant to the battery pack. It then travels to the propulsion unit which supplies power to the electric drive motor. The control signals, which will be sent and received by the National Instruments system, are indicated by the peach arrows and the blue arrows. The type of communication scheme employed between different parts is written on the diagram. For further clarification, the location of all of these systems in the vehicle can be found in Figure 2.

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Figure 1: System Layout Block Diagram

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Figure 2: Vehicle Location Block Diagram

In the following section of the report, each of the physical components of the hybrid electric HMMWV will be discussed. Within this discussion, the characteristics of the components will be presented. If the component was designed, the steps followed in the conceptual design will be presented, along with the results of the modeling done on those systems. If the component was purchased, the process and reasoning behind the component selection will be presented.

1 Volkswagen Turbo-Diesel Engine and UQM Motor

The Volkswagen turbo-diesel engine came installed in the HMMWV. It is an engine that is normally used in the Jetta car made by Volkswagen. The purpose of the diesel engine is to act as the mechanical powerplant that turns the 53 kW UQM motor attached to it. The motor then basically acts like the alternator in a typical fuel driven vehicle, converting mechanical energy into electrical output. To control the interface between the diesel engine and electric motor, CTC (Concurrent Technologies Corporation) purchased a controller unit from UQM Technologies Inc. Fortunately this controller was not damaged when the other CTC designed electrical systems were damaged. From discussions with engineers at CTC, we knew that the controller was used to configure the motor as a generator; which was then used to charge the batteries. However, we were not given any documentation as to which pins on the controller needed what input. We spent time working with the Volkswagen dealer, CTC, and UQM Technologies to determine what inputs the controller needed to function in generator mode. A wiring diagram of the controller connector and the signals it requires for operation can be found in Appendix A. A picture of this controller can be found in Figure 3.

Figure 3: UQM Engine Controller

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The Volkswagen engine is the main power generation driver of the moving HMMWV. When the vehicle is started, the engine is turned on and should run at the optimal point in its torque curve. Volkswagen specified this point on the torque curve. The engine is not mechanically connected to the drive-train of the vehicle. It is only used to charge the batteries or power the motor, depending on demand, through the generator while the vehicle is in operation. A picture of the UQM Generator and the VW diesel engine can be found in Figure 4.

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Figure 4: Power Plant

We discovered that the bell-housing on the engine had been permanently altered by CTC. The bell-housing is where the starter is mounted and in this case that mounting feature had been removed. It was apparent that the previous propulsion system had been configured with the UQM controller to start the engine. We did not have this option with the AC Propulsion Unit, so we did some research through UQM and discovered that the engine could also be started using only the UQM controller and motor in conjunction with a starting circuit. The starting circuit is pictured below in Figure 5. F1 and F2 are fuses. Y1 and Y2 are switches. R1 is a resistor. We assembled this starting circuit and were able to run the motor and subsequently start the engine. For more information on the starting circuit please refer to the UQM product manual which is included in the accompanying CD.

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Figure 5: Starting Circuit

2 AC Propulsion 150 KW Generation II® Propulsion Unit

Another component that we were able to salvage from CTC’s hybrid electric HMMWV design was the propulsion unit. Originally, CTC purchased an electric propulsion unit and electric motor from AC Propulsion Incorporated to work as a charger for the batteries when they were not in use. The AC Propulsion 150KW Generation II® Propulsion unit has the ability to plug directly into the wall to charge the batteries. When we discovered that the recharging system was actually a propulsion system configured differently, we called AC Propulsion and negotiated a price of $5,000 to reconfigure our propulsion unit to a full 150KW Generation II® propulsion unit. If we had needed to purchase this unit new, it would have cost us $25,000. Cost was the main influence in our decision to refurbish this unit rather than purchase a new unit. The operating characteristics of the AC Propulsion 150KW Generation II® propulsion unit can be found in Table 1 below.

Table 1: Characteristics of the AC Propulsion 150KW Propulsion Unit

|Voltage |Current |Torque |Power |Efficiency |

|336-360V DC Nominal |580A max (drive) |220Nm |150kW max |86% (road load) |

A second factor in our decision to refurbish the AC Propulsion 150KW Generation II® propulsion unit was the fact that our customer had recommended AC Propulsion as a quality company. Dr. Edwards had previous experience with AC Propulsion 150KW Generation I® propulsion unit in another hybrid vehicle project and was very impressed. This further enforced our decision to use the AC Propulsion 150KW Generation II® propulsion unit. This propulsion unit is pictured in Figure 6.

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Figure 6: AC Propulsion 150KW Propulsion Unit

3 AC Propulsion Electric Drive Motor and Planetary Gear Reducer

To incorporate the electric drive motor into the drive train of the HMMWV, there were two different integration issues that needed to be addressed: 1) at what gear reduction from the motor to the axle will the electric motor produce enough low-end torque to propel the HMMWV and 2) how will we mount the longer, heavier electric motor to the vehicle. These designs are addressed in the following sections of the report.

1 Gear Reduction Calculation

The AC Propulsion 150KW Generation II® propulsion unit is able to output 12000 revolutions per minute (rpm), 150 kW (200 horsepower), and 220 Newton-meters (165 pound-feed) of torque at maximum output. These characteristics make it ideal to drive a car the size of a Honda Civic® through the full range of speeds without a transmission. However, the HMMWV has much more mass than a Honda Civic; therefore, we needed to calculate what gear reduction was need to provide adequate power to drive the HMMWV over the zero to 60 mile per hour speed range.

In previous semesters, the Future Truck team, at the University of Idaho, had developed a MatLAB® program to calculate the drive response of a vehicle to different input horsepower motors. The code for this program can be found in the CD of files that will accompany this report. We used this program to calculate how the HMMWV would perform if the electric motor was coupled directly onto the rear axle of the vehicle. There are two gear reductions, common to every HMMWV, which are included in the coupling to the axle: 1) a 4.10 to 1 ring and pinion, and 2) the 1.92 to 1 hub reduction. The ring and pinion are the gears that are used to transfer the power from the drive shaft, leaving the motor to the two drive axles driving the tires. The hub reduction is a stock gear reduction included in the hub. To calculate the total reduction of this situation, the individual system reductions must be multiplied together. Therefore, coupling the motor directly to the drive shaft would give it a gear reduction to the wheels of 7.872. We performed the simulations with only these gear reductions included and found that the HMMWV would not have enough torque to perform at low speeds, which meant that the vehicle might not be able to start from a dead stop.

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Figure 7: Planetary Gear Reducer

After performing this first set of calculations we knew that we needed to include another gear reducer to increase the gear reduction from the electric motor to the rear axle. This would increase the torque of the vehicle and provide better low-speed performance in the hybrid electric HMMWV. We decided to include a 2.5 to 1 planetary gear reducer built for use on past Future Truck projects. When this reduction is multiplied with the reduction already present in the HMMWV the total gear reduction becomes 19.68 to 1. This is a big improvement over the previous gear reduction. A picture of this gear reducer can be found in Figure 7. We simulated the HMMWV’s operational characteristics with this new gear reduction ratio and found that it would have good operational characteristics up to 30 miles per hour. The results of the MatLAB® Simulations can be found in Figure 8. At that point the electric motor would not be able to output any more horsepower. We leave it up to future groups to include either a transmission or to incorporate another propulsion system to improve the operating characteristics of the HMMWV to standard scales. We have left physical room on the vehicle for these systems and are confident they could be incorporated into our design.

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Figure 8: Simulated HMMWV Response with One Propulsion Unit

2 Motor Mounting Design

The biggest challenge with the motor mounting design was the fact that the new electric motor was much longer than the electric motor previously mounted to the rear axle of the vehicle. This was complicated by the fact that we decided to add a planetary gear reduction unit. The addition of the gear reduction unit increased the distance that the electric motor would need to be mounted away from the back axle. The final mounting design had to support this additional weight cantilevered from the rear axle. To do this an angle iron cross member was added to support the planetary gear reducer and electric motor.

The interface between the AC Propulsion electric motor and the gear reducer was very easy because the gear reducer was designed to be mounted on an AC-150. To mount these to components a .375 inch adapter plate had to be manufactured because the one previously used had not been recovered when the gear reducer was removed from the Future Truck. Furthermore there were two more components that required manufacturing to install the drive system. The first being a .80 inch adapter plate that would bolt the planetary gear reducer to the previous motor adapter on the rear axle. This adapter had to align the center of the drive shaft in the rear axle to the center of the output of the planetary gear reducer. To do this dowel pins and a line up boss were used. To transfer the power from the planetary gear reducer to the drive axle a shaft was need. This shaft had to bolt onto the pinion flange of the rear axle and engage into the spline in the planet. This shaft was rough machined on the CNC lathe then heat treated to Rockwell C 31.5 to increase the strength to 135,000 psi. This was done to increase the allowable torque loads to 67,500 psi. With this we have a safety factor of 2.2 on the torsion analysis of the shaft. This information can be analyzed by looking at appendix XX.

The final mounting design can be found in Figure 9 and the components that were designed to facilitate this mounting can be found in Figure 10.

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Figure 9: Motor Mounting

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Figure 10: Components Developed for the Final Mounting Design

4 Control and Data Acquisition System

Two other design decisions that the team faced were: 1) how to control the various systems within the vehicle and 2) how to collect data on the operation of the batteries. We decided to implement these two designs using the National Instrument’s PXI-based instrumentation system. We decided to use this piece of equipment because the system had the following characteristics: 1) re-configurable, 2) robust, 3) understandable, 4) re-programmable and 5) the individual parts that make up the system are easily replicable. We settled on these criteria because of the multiple year nature of the project. We wanted to have a system that any team could use after a short introduction so that the future researchers would be able to easily understand and use it. Also, we cannot know what will be required of the HMMWV in the upcoming years. The more versatile the system is, the better chance that it can meet future requirements. In the case that a part in the system breaks, we wanted future teams to be able to easily replace the part without having to redesign the system. These are the reasons why we decided to purchase the National Instrument's PXI-based chassis instrumentation system. Figure 11 is a picture of the general PXI-based chassis instrumentation system offered by National Instruments.

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Figure 11: National Instruments PXI-Based Chassis System

1 System Control

The National Instrument PXI-based chassis instrumentation system is equipped with the following communications protocols: RS232 and CAN. These protocols will allow the PXI-based chassis system to communicate with the other subsystems within the vehicle. It can communicate with the AC Propulsion 150KW Generation II® propulsion unit and the UQM controller unit for the diesel generator. It also controls the thermal management system of the battery enclosure by controlling a relay that turns the fans on and off.

2 Data Acquisition

The National Instrument PXI Chassis based instrumentation system is equipped with 100 data acquisition ports when equipped with the cards that we bought. The amount of ports can be expanded with the addition of more cards. The National Instrument PXI-based chassis instrumentation system is wired to take 34 voltage readings and 40 temperature readings. The voltage acquisition included 30 voltages from the battery pack, one for each individual battery, 2 high voltage readings from the terminals of the battery pack, and 2 voltage readings from the auxiliary systems. The thermal data acquisition included 30 thermal inputs on the surface of the batteries themselves and 10 for the temperature gradients in the box.

5 Battery Enclosure and Battery Pack

There were two decisions to be made when we designed the battery enclosure and the battery pack: 1) where to place the battery enclosure and 2) what batteries to use while the advanced batteries were still being built.

1 Battery Enclosure Placement

One of the main design decisions for the HE-HMMWV was the placement of the battery enclosure. Originally, we had hoped to fit the enclosure between the frame rails of the HMMWV. This design can be found in Figure 12. However, when we started looking at the dimensions of the AC Propulsion motor and the gear reduction assembly, we found that the batteries would not easily fit under the vehicle. We decided, with Dr. Edwards’ input, that the battery enclosure would work if it was placed in the bed of the HMMWV. By placing the enclosure in the bed of the vehicle, we would be able to limit the layers of batteries. This would lengthen the battery life because we could cool them more efficiently with fewer layers. It would also eliminate the design of a complex, multi-level mounting system for at least the surrogate batteries. By placing the battery enclosure on the bed of the vehicle, we also would have much easier access to the batteries. However, when we designed the battery enclosure for in-bed placement on the vehicle, we found that it made accessing the front electrical boxes difficult. To fix this issue, we mounted the battery enclosure on rails so that it could be slid backward, exposing the electrical boxes below. This will help with future maintenance of the system. The final design of the battery enclosure when it is placed on the bed of the HMMWV can be found in Figure 13.

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Figure 12: Original Battery Enclosure Design - Under Vehicle

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Figure 13: Final Battery Enclosure Design – On Bed

2 Surrogate Batteries

There will be a period of time when the vehicle is ready to be tested and the advanced lead acid batteries are not available to supply power to the system. We will need to have batteries to verify the system design while waiting for the advanced batteries to be delivered. The criterion we used to pick the replacement batteries was as follows: 1) inexpensive. The batteries that fit the best into the battery enclosure are the size 70 car battery. Using this battery allowed for several inches of room between the terminals of the batteries. This is essential due to the high voltage nature of our battery pack. We do not want to short any of the terminals together because this could cause an explosion. The operational characteristics of the batteries were not a criterion because there are no batteries on the markets that have similar power characteristics to advanced lead acid batteries. Helbling Machining and Auto Parts supplied us with 30 size 70 car-batteries for a discounted price. The surrogate batteries that we used are pictured in Figure 14.

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Figure 14: Surrogate Batteries

6 Thermal Management Design

Thermal management of the battery enclosure was another main design decision that our team faced. One of our main project constraints was that the battery enclosure had to be maintained between 80˚F and 120˚F. Batteries charge and discharge optimally at these conditions. Also, batteries tend to have longer lives when this temperature range is maintained. For these reasons, the thermal management was especially important to our project. Our client, Dr. Dean Edwards, suggested that we test the theories put forth in a study conducted by Aerovironment Incorporated for the thermal management of a similar military vehicle, the J-TEV. This system was implemented using forced air heating and cooling along with a baffle system to ensure airflow across the maximum heat transfer surfaces of the battery. This year we focused on the cooling part of the system.

The fans which were chosen to provide the forced air cooling in the battery enclosure are shown in Figure 13. These fans were chosen for the following reasons: they provide an inch and a half of water pressure at 250 CFM, and have the ability to be powered by the 24V auxiliary power system required by the HMMWV’s gages and headlights. The CFM and pressure specifications were taken from recommendations made by AeroVironment Incorporated’s study. This study can be found in the CD that accompanies this report. When operating at 24V, each fan provides 250 cubic feet per minute worth of air flow at 1.5 inches of water pressure. This will provide adequate air-flow to keep the battery enclosure within the temperature range that was specified. Figure 15 shows a picture of the fans that were purchased for the system and Table 2 is a condensed list of the main characteristics of these fans.

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Figure 15: Fans Purchased for the Thermal Management System

Table 2: Characteristics of Battery Enclosure Fans

|CFM |V (DC) |Voltage Range (DC) |Power (W) |Noise (dB) |

|529.7 (at 0 pres.) |24 |16 - 28 |93 |68 |

7 DC to DC Converters

Originally, the HMMWV was a diesel vehicle and all of the gauges and electrical systems were powered using a 24V battery. These original systems will need power in the Hybrid-Electric HMMWV. To supply these systems with power we decided to use a DC to DC converter to change the 360V from the battery pack to the 24V DC that the on-board systems required. We also added some systems that required 12V DC for operation. This made a second converter necessary. The converters had to be able to supply 80 amps for the 24V system and at least 10 amps for the 12V system. The high voltage and current required limited the choice of manufacturers to two companies that specialized in industrial converters: 1) Vicor Corporation and 2) Schaefer Electric Corporation. Vicor Corporation's Vipac Array DC to DC converters were less expensive, easier to implement, and met all of the system requirements. These converters can be found pictured in Figure16, and a table containing their operational characteristics can be found in Table 3.

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Figure 16: Vicor Vipac DC/DC Converter

Table 3: Characteristics of Vipac DC/DC Converters

|Voltage In |Voltage Out |Efficiency |Maximum Operating |Current Sharing? |Power Density |

| | | |Temperature |(Parallelable) | |

|360 V DC |12 or 24V DC |87% |100˚C |YES |118W/cubic inch |

SYSTEM INTEGRATION

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The overall HMMWV design was made up of smaller subsystems. These subsystems were listed in the previous design section. In this section of the report the interaction and interconnection between these subsystems and the system as a whole will be described. There are four main interconnections that the team made between subsystems in the Hybrid Electric HMMWV: 1) power interconnections, 2) data acquisition interconnections, 3) control interconnections, and 4) user interface. In the following subsections the interconnected systems, the connections between them, and the problems we faced while making these connections will be described.

1 Power Interconnections

There are actually two main power systems within the vehicle. There is the main driveline power bus and the auxiliary power bus. The main power bus is the bus that operates the drive train of the vehicle. Since our vehicle is a series Hybrid Electric vehicle, the driveline is one directional. The power from the diesel power plant must be routed to charge the battery pack. The battery pack then supplies power to the AC Propulsion 150KW Generation II electric propulsion unit and the DC to DC converters. The AC Propulsion system then supplies power to the electric drive motor. In this configuration only the electric drive motor is attached to the axle of the vehicle.

The power plant is powered initially by 360V DC from the battery pack. After starting, the power plant is powered from the diesel tank at the back of the vehicle. The power plant produces 360V DC which is used to charge the battery pack. This connection was made by connecting a positive and negative power cable from the output of the inverter to the terminals of the battery pack. The terminals of the battery pack are connected to the input of the AC Propulsion 150KW Generation II electric propulsion unit with two power cables from the terminals of the battery pack. The same was done for the generator and the DC/DC converters. The AC Propulsion 150KW Generation II electric propulsion unit has designated connections for the electric drive unit. For more information on these connections, please see the interface manual which is provided in the accompanying CD.

The auxiliary power system is a set of connections that supply 12V DC and 24V DC to support systems throughout the vehicle. It is powered from the 360V DC power system through the DC to DC converters. The power from these converters is used to charge two separate batteries. This was done to ensure that steering, braking, and control of the vehicle would still be functional if the drive train were to fail. Another main consideration for the auxiliary systems was fusing. All of the subsystems in the vehicle were connected to power through fuses to protect the equipment. This connection was made immediately after the DC to DC converters and before power was routed to individual systems.

Some of the auxiliary systems require power at all times. These systems were supplied power directly from the fuse block of the auxiliary system. These systems include the 12V DC and 24V DC parts of the National Instruments PXI-based instrumentation system, the 24V DC supply to the thermal management fans in the battery box, and the 12V DC touch screen.

Other parts of the auxiliary system only required power when the vehicle was in drive mode. These systems were routed through relays before power was distributed to them. The power to the coil of the relays was routed from the starting switch of the vehicle. The systems that get power from these relays are as follows: 1) the start signal of the AC Propulsion 150KW Generation II electric propulsion unit, 2) the start signal of the inverter, 3) the oil pump and fan used to cool the electric drive motor, 4) the original driving gages of the HMMWV, 5) the radiator fan for the power plant, and 6) the head and tail lights of the HMMWV.

2 Data Acquisition Interconnections

The data acquisition in the HMMWV is handled by the National Instruments PXI-based instrumentation system. The National Instruments PXI-based instrumentation system collects temperature and voltage readings from the battery enclosure stores and displays them on the touch screen. Each temperature reading corresponds to a thermal couple which is attached to a particular battery or location in the battery box. These thermal couples are routed through circular connectors that are mounted in the battery box and connected into two SCXI 1102 Cards which are located in slots one and two of the National Instruments PXI-based instrumentation system. There is more than one type of voltage reading being taken by the National Instruments PXI-based instrumentation system. The first type of voltage reading is the voltages of each of the individual batteries in the battery pack. These connections are routed on two wires from each battery through a circular connection in the wall of the battery enclosure to the SCXI 1104 Card which is located in slot four of the National Instruments PXI-based instrumentation system. There is also a high voltage reading being taken at the terminals of the battery pack. This is routed to the SCXI card located in slot four of the National Instruments PXI-based instrumentation system.

There is also data being collected from some of the subsystems by the National Instruments PXI-based instrumentation system. The only system that we have been able to collect data from successfully is the DC to DC Converters. The output terminals of these converters are routed to the SCXI 1104 Card located in slot four of the National Instruments PXI-based instrumentation system. Theoretically, we should be able to collect data on the CAN 2.0 bus from both the AC Propulsion 150KW Generation II propulsion unit and the power plant, but we didn’t have time to work out these connections. The ability to access the units on the CAN 2.0 protocol is included in the National Instruments PXI-based instrumentation system, but it hasn’t been connected yet.

3 Control Interconnections

There is several control systems incorporated into the Hybrid Electric HMMWV: 1) driver input control, 2) battery charging and thermal management control, and 3) power plant control.

The driver input control is handled by the AC Propulsion 150KW Generation II electric propulsion unit. Information from the acceleration potentiometer is input to the AC Propulsion 150KW Generation II electric propulsion unit which then converts it to a meaningful control signal for the electric drive motor. When there input from the accelerator potentiometer is such that the accelerator is not being depressed by the drive the AC Propulsion 150KW Generation II electric propulsion unit immediately goes into regeneration mode and charges the battery pack with the energy in the electric motor.

The battery charging and thermal management control is handled through the National Instruments PXI-based instrumentation system. Since this system is already collecting voltage and temperature data for the data acquisition system, it already has all the information it needs to protect the batteries from excessive charging and excessive temperature. If any of the batteries exceeds 14V DC in charging the National Instruments PXI-based instrumentation system sends a signal to the AC Propulsion 150KW Generation II electric propulsion unit through the partially connected VMS system to discontinue charging. The VMS system is an AC Propulsion data acquisition and control system that is partially installed in the vehicle this year to allow for charging the batteries from a wall outlet. There is more information on the connection of this system in the future work section of this report. If the battery pack exceeds 400V DC during charging the National Instruments PXI-based instrumentation system sends a signal to the AC Propulsion 150KW Generation II electric propulsion unit through the partially connected VMS system to discontinue charging. If the temperature exceeds 110°F at any point in the battery enclosure the National Instruments PXI-based instrumentation system will turn the thermal management fans on. There is also an option to manually control these fans through the touch screen while operating the HMMWV.

The final control system in the Hybrid Electric HMMWV is the power plant control. This is accomplished mainly through the UQM controller. This controller needs a starting signal from the starting circuit described in a previous section. The starting circuit is controlled by the run switch in the passenger compartment. The idle speed of the generator and engine should be controllable through a potentiometer that is connected in the dash; however, we have not been able to control the power plant consistently with this potentiometer. There are quite a few issues with this control system and they are discussed in detail in Section 7.1 of this report.

4 User Interface

To program our user interface, we have chosen to use LabVIEW® software that is packaged with the National Instruments PXI-based instrumentation system. LabVIEW® is a graphical programming language. This means that instead of writing syntax based code, like C or PERL, the code is displayed as boxes for each function with wires describing commands connecting them. A sample coding screen shot can be found in Figure 17.

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Figure 17: LabVIEW Code Screen Shot

The user interface for the National Instruments PXI-based chassis instrumentation system is a touch screen. Since the system will be used by both researchers and military personnel, we decided to have two modes on our user interface. The first mode is for a normal operator. In this mode, the main systems are displayed as colored buttons. If the system is operational, the button is green, in the “go” state. If the subsystem is non-operational, it is displayed in red, which is the “no-go” state. The second mode is a graphical mode where the battery voltages and temperatures are displayed in graph format. These graphs start when the vehicle is turned on and are continually updating during operation. All of the information collected by the NI system will be stored within the system and is available to download when the testing is completed. Figures 18 and 19 show a screen shot of the go/no-go mode and the graphical mode on the touch screen.

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Figure 18: Go/No-Go Mode for User Interface

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Figure 19: Graphical Mode for User Interface

PRODUCT EVALUATION

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When we evaluated the final HMMWV design, we wanted to determine if the vehicle met the original project requirements. These requirements are listed as follows:

1) the HMMWV must be a self-propelled “rolling” vehicle, 2) the HMMWV must have a thermal management system in place that will keep the battery enclosure between 80 and 120˚F, 3) the HMMWV must have a data acquisition platform in place to monitor the voltages and temperatures of the batteries and display them, and 4) the voltage at the battery bus must be 360V DC. The sections that follow focus on each of these design requirements, our solutions to these requirements are explained, and the ability of our solutions to meet the requirements will be presented. Finally, the results of how our internal design failure affects mode analysis will be presented. This documentation was our attempt to forecast future design problems and engineer solutions to them.

1 Self Propelled Vehicle

We were able to drive the HMMWV to the final senior design expo to present it to our peers on April 28, 2006. We had hoped that our HMMWV would perform like a standard military HMMWV; however, due to financial and time constraints, we were only able to include one AC propulsion unit, leaving the vehicle underpowered. The HMMWV did perform as we expected, and we were able to drive up to 30 miles per hour. At the end of the project the HMMWV was driven by President White. Therefore, we met the self-propelled vehicle requirement of the project.

2 Battery Thermal Management System

One of the main design decisions was how to implement an efficient thermal management system. We used our temporary batteries to test the forced air system's characteristics before the new batteries were subjected to the environment. Using the previous thermal study conducted by Aeroviornment Incorporated, we implemented a forced air cooling environment in the battery enclosure. We found that this system works well when the fans are controlled by the NI chassis system in conjunction with the temperature probes located in the battery box. We were able to strobe the fans on and off at a reasonable rate for the fans to keep the battery enclosure between 80 and 120˚F. We met the design requirement in this stage; and, in doing so, we proved that forced air cooling is a viable alternative for battery enclosure thermal management.

3 Data Acquisition System

The data acquisition system was implemented using the National Instruments PXI-based chassis instrumentation system. This system monitored 40 thermal inputs from the battery box. This included 30 thermal inputs on the surface of the batteries themselves and 10 for the temperature gradients in the box. This data is available to the driver during test runs both as a button that tells if the temperature is in range and as a graph of the temperatures over the time of the tests. The data acquisition also has information on voltages within the battery pack and throughout the vehicle. There are 34 channels of voltages: 30 from the battery pack, 2 high voltages, and 2 from different places within the vehicle. These voltages are displayed in the same manner as the temperature readings. Both temperatures and voltages are displayed in an easily accessible format and available for downloading at the completion of tests. These are the requirements for the data acquisition system; therefore, we have met this requirement, as well.

4 Unified Battery Bus

The unified battery bus was a main part of our design from the beginning of the process. Since we were not able to salvage the previous system we made the battery bus 360V when we started our design. This was accomplished by implementing the battery pack with 30, 12V car batteries configured in series. The final battery bus is unified at 360V.

5 Design Failure Modes and Effects Analysis

Throughout the design process, we have used design failure modes and effects analysis (DFMEA) to determine possible failures and effects of those failures. There were three main categories which lead to the final DFMEA score: 1) the severity of the scenario, 2) the probability of the scenario, and 3) the ability to detect the scenario. The final DFMEA score is obtained by multiplying the three scores from these sections. The higher the score, the worse the failure would be. The detailed DFMEA can be found in Appendix D. The following are the primary modes of failure found by the DFMEA:

1. Shorted Battery Cabling

2. Battery Failure

3. Battery Enclosure Fire

4. Thermal Management Fan Failure

5. Charging Mode Failure

6. Starting Circuit Failure

7. Data Acquisition doesn’t get inputs

8. Electric Motor PEU Failure

ECONOMIC ANALYSIS

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We believe that this project was an economically sound project. The goal of this project was not to design a production model hybrid electric HMMWV, but to design a versatile test bed for new battery technology. We have accomplished this in the hybrid electric HMMWV with a budget that was reasonable. All of the products purchased for the design of the Hybrid-Electric HMMWV were researched thoroughly and all alternatives were considered before any parts were purchased. Many of the products required to hybridize a vehicle were either custom-made or were hard to find. As a result, these products were more expensive. We actively worked to keep the budget in a reasonable range. The military spends more on one new diesel HMMWV than we spent refurbishing our HMMWV and turning it into a Hybrid Electric Vehicle. The expenditures of this project can be found in Table 4 below.

Table 4: Detailed Budget by Item

|Detailed Budget By Item |

|Item |Subcategory |  |Proposed Budget |Final Budget |

|Proposed |  |  |$45,000.00 |$48,000.00 |

|Propulsion System |

|  |AC 150 Retrofit |  |($5,000.00) |($6,100.00) |

|  |Misc Mounting |  |($200.00) |  |

|  |flange adapter |  |($424.07) |($469.77) |

|  |shipping |  |($100.00) |($227.82) |

|  |Speedo Sensor |  |($183.00) |($182.00) |

|  |  |  |  |  |

|Thermal management (Battery Box) |

|  |Fans |  |($400.00) |($655.95) |

|  |Heater |  |($3,000.00) |$0.00 |

|  |  |  |  |  |

|Batteries |

|  |commercial |  |($1,600.00) |($1,350.00) |

|  |core charge |  |  |$125.00 |

|  |  |  |  |  |

|Battery Management System |

|  |VMS/VTMS*32 |  |($4,800.00) |($4,828.13) |

|  |  |  |  |  |

|Battery Box Modification |  |  |

|  |Battery mounting and box support |  |($477.00) |($678.89) |

|  |Battery Support Assy |  |($535.11) |($575.70) |

|  |Battery Box Assy |  |($1,500.00) |($1,500.00) |

|  |  |  |  |  |

|Instrumentation |

|  |NI PXI chassis |  |($18,000.00) |($17,887.44) |

|  |Touch Screen display |  |$0.00 |$0.00 |

|  |  |  |  |  |

|Power distribution |

|  |DCDC |  |($1,661.00) |($1,611.00) |

|  |GFI |  |($250.00) |($250.00) |

|  |  |  |  |  |

|Shipping |

|  |  |  |($7,974.70) |($7,974.70) |

|Incidentals |

|  |Cabling |  |($1,000.00) |($750.00) |

|  |Connectors |  |($1,000.00) |($389.00) |

|  |

| | |Money Received |$45,000.00 |$48,000.00 |

| | |Money Spent |($48,104.88) |($45,305.40) |

| | |Difference |($3,104.88) |$2,694.60 |

Not included in this table is the time we spent on conceptual design, drafting, drawing and manufacturing in the shop. We do not feel that it is necessary to include these costs due to the fact that this project is a test bed and is not going to be mass-produced. However, we will include an estimated cost for the amount of time we spent on each of these actions for clarification. We were told to estimate our engineering time as 25 dollars an hour which leads to the dollar figures. These estimations can be found in Table 5.

Table 5: Engineering Time Cost Summary

|Work Categories |Time Spent on Completion of Categories |Estimated Engineering Cost |

|Conceptual Design |200 hours | $5,000.00 |

|Coding Time |200 hours | $5,000.00 |

|Drafting Time |100 hours | $2,500.00 |

|Manufacturing Time |200 hours | $5,000.00 |

|Assembly Time |1000 hours |$25,000.00 |

|Documentation Time |200 hours | $5,000.00 |

|TOTAL |1900 hours |$47,500.00 |

FUTURE RECOMMENDATIONS

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This project is a multi-year project. Therefore, instead of preparing our conclusions on a project that is incomplete, we will lay out the design decisions that we would like to see addressed by future teams. These design decisions would lead to the following operational characteristics: 1) a power plant that is incorporated into the drive train of the vehicle 2) stock performance characteristics of the HE-HMMWV, 3) 4 wheel drive capability, 4) battery enclosure that is updated for Dr. Edward’s advanced batteries, 5) forced air heating of the battery enclosure, 6) AC Propulsion Battery Monitoring System integrated into the data acquisition system, 7) Bender GFI system integrated into the safety control system, 8) data acquisition code optimized, 9) driver interface improved, 10) HMMWV that can be used as a portable generation unit, 11) charge monitoring and current shunting systems for the battery pack, 12) Bio-diesel incorporated into the diesel systems of the HMMWV, and 13) a self sufficient system control system without data acquisition.

1 Generator and Engine Incorporation

At the end of our stage of the Hybrid Electric HMMWV project the vehicle is completely operating from the battery pack. We have constructed the starting circuit required for the engine, and have been able to start the engine using this starting circuit. Due to the time constraints of the semester we were not able to gain throttle control of the engine and test the generation ability of the vehicle. The engine will start, however both the stock potentiometer and a new potentiometer operating at specs produce no change in rpm. The engine fluctuates in rpm from hundreds to red line and back with an unknown control signal at this time. The engine also produces a moderately intense pre-ignition type of noise upon its self induced accelerations to red line. This was ugly, but maybe not so uncommon for a cold diesel engine under full throttle conditions. The generator in its starter role turns the engine well with the exception of sometimes sticking in multiple positions and failing to move at all. We overcame this in testing through the use of a socket wrench on a pulley nut from underneath of the vehicle. Every time it would move slightly and stick, or not move at all, we would simply turn it slightly more and it would appear to come out of a bind. This is obviously indicative of an issue that has yet to be identified and dealt with. Throttle control needs to be gained, the engine ping needs to be evaluated, the sticking starting positions of the generator need to be problem solved, and the generator needs to be load tested.

2 Performance Characteristics of Hybrid-Electric HMMWV

We would like the HE-HMMWV to perform like the diesel version of the vehicle. We were unable to meet this criterion this year due to financial constraints. There are two different ways to accomplish this: 1) add another propulsion unit in parallel with the existing AC Propulsion unit or 2) add a transmission. The second propulsion unit would supply more available power to propel the vehicle. It could be placed on the front axle. This solution would require a communication scheme to make sure that the two units worked as a single unit, and not against one another. This could easily be accomplished with the expandability of the National Instruments system. The second option would allow for different gear ratios at different speeds of the vehicle. This would improve the performance of the single propulsion unit, or it could be used with two propulsion units. We have left physical room in the vehicle for either or both of these systems. We leave it up to future teams to decide how to solve this engineering problem.

3 4 Wheel Drive Capability

We would also like the vehicle to have 4 wheel drive capabilities. This is an attribute that we wanted to include on the vehicle at the beginning of the project, but that was abandoned due to lack of time. This can also be accomplished more than one way. With two propulsion units and two electric drive motors, a mechanical gearing scheme could make each tire independent and implement the 4wd capability. Another option is to put four drive motors on the vehicle, one for each wheel. The second option would require communication between each motor. Again, we would like to see this option implemented in a future team's design solution to this problem.

4 Updated Battery Enclosure

We have proven that forced air cooling using large fans and baffles is an effective way to cool a battery enclosure. However, there is some design work that must be completed before our thermal management system can be used on Dr. Edward’s batteries. The surrogate batteries that we used were most effectively cooled and heated by passing air across the side surfaces of the batteries. Therefore, we have designed our thermal management system to funnel the cooling air across the side surfaces of the batteries. Dr. Edward’s batteries are most effectively cooled and heated by passing air across the top and bottom surface of the batteries. Before implementing our thermal management system on Dr. Edward’s batteries, the air flow will have to be restructured to pass across the correct surfaces of the batteries. This will essentially require a new battery enclosure design. The concepts which were used to design our battery box are still applicable in the new design. This is essential to the correct operation of the thermal management system with Dr. Edward’s batteries in it. This design decision should be addressed at the beginning of the project.

5 Forced Air Heating of the Battery Enclosure

We did not have time to implement the forced air heating of the battery enclosure due to time constraints this year. However, it can be easily implemented once the air flow of the new battery enclosure is designed by the future team. There are two ways to implement forced air heating: 1) by piping in the heat produced in the engine compartment of the vehicle, or 2) by buying a heater and using the fans to distribute the heat, or 3) heating pads that could be directly applied to the surface of the batteries. Dr. Edwards told us this year that he would prefer the second method because it is easier to control than piping in heat produced by other components already present on the vehicle.

6 AC Propulsion Battery Monitoring System

Dr. Edwards asked us to purchase a new generation battery monitoring system that AC Propulsion was developing this year. Originally, we were under the impression that this system would be ready to connect to the vehicle during our stage of the project. However, we were informed by engineers at AC Propulsion that the system would not be ready before we were to graduate. We did receive the system in time to incorporate it partially into the vehicle. The connected the LCD screens and the main module to the system to power, ground, and routed the system’s control signals to the AC Propulsion 150KW Generation II Propulsion unit. The hardest part of this connection is that the system is grounded through the screens, and this connection has to be made for the system to work. This allowed us to charge the batteries from a wall outlet through the AC Propulsion 150KW Generation II Propulsion unit. We understand that the system will monitor the voltage and current produced by each battery and store the information for retrieval when the vehicle is shut down. This component has already been ordered and paid for with our budget; the future team needs only to install it. We are concerned that the manual provided for this piece of equipment is not up to date. This will have to be addressed by future students.

7 Ground Fault Interruption System

We ordered a GFI system from Bender Incorporated this year; however, it did not arrive in time for us to install it in the hybrid electric vehicle. This system will protect the driver and research staff working on the hybrid electric vehicle by displaying a warning light if there is a small current leakage through the vehicle and by disconnecting the battery pack from the vehicle if there is life threatening current leakage through the body of the vehicle. For safety, it is essential that this piece of equipment be incorporated as soon as it arrives.

8 Optimized Data Acquisition Code

This year we developed a working prototype for the data acquisition code. This code is fully functional; however, it could use work by a future team mate to optimize its operational characteristics. With some future work the code could run faster, be more dependable, and be tailored more specifically to the requirements of the battery research team.

9 Improved Driver Interface

Within the budget and time constraints of the project this year we developed a touch screen based driver interface system. The touch screen that we implemented this system with was a small 3” by 5” touch screen that was previously on the Future Truck. The system works well; however it is very small and hard to read. We would like to see a larger interface installed in the vehicle in the future. Also, there is no back up indicators currently installed in the vehicle if the touch screen were to fail. We would like to see a LED based indicator system installed as a backup option in case of touch screen errors. Also, we would like to see a switch control to override automatic controls implemented and installed. It is always a good idea to have manual control of the system.

10 Portable Generation Unit

One of the original long-term ideas behind converting the HMMWV to a hybrid electric vehicle was its possible use as a mobile generation unit. Essentially, this means that when the vehicle is parked, the batteries can be used to supply power to a military outpost. These vehicles could theoretically be wired together in parallel, allowing vehicles to be introduced and removed to maintain power to the outpost. We would like to see this idea developed and experimented on by future teams.

11 Charge Monitoring and Current Shunting Capability

In the more advanced battery pack powered systems, the battery life is lengthened by incorporating a system that ensures that each battery is charged to the same voltage and that an equivalent amount of current is being drawn from each battery within the pack. This ensures that all batteries have the same demand on them. Since none of the batteries have excess demand on them this lengthens their life. We would like to see future teams on the HMMWV look into the possibility of adding such a system to our hybrid electric vehicle.

12 Bio-Diesel Incorporation

University of Idaho has a very well developed bio-diesel program. The team members have expressed interest in perhaps making the diesel generator capable of using the bio-diesel that is developed here on campus. There would be a large group of people who could be asked for help and input on this incorporation. We think it would be exciting to have the world’s first fully environmentally friendly HMMWV. This could also be good PR for the university and the Office of Naval Research.

13 Self Sufficient Control System

In the first stage of the project our goal was to develop a research test bed for the advanced lead-acid battery technology that is currently in development at the University of Idaho. For this application it makes sense to have versatile data acquisition and display capabilities; however, this vehicle will only be used as a test bed in the next few years. It is our hope that this system can be modified away from the PXI based system into a control system that would be more applicable to the typical driving requirements of the hybrid electric HMMWV.

APPENDIX A: SYSTEM WIRING DIAGRAMS

APPENDIX B: MECHANICAL DRAWING PACKAGES

Battery Enclosure Drawing Package

Gear Reducer and Motor Mounting Drawing Package

APPENDIX C: INSTRUCTION AND REPAIR MANUALS

Safety Procedures for HEV Shop

Technical Manual for Disassembly and Assembly of the Battery Pack

Technical Manual for Disassembly and Assembly of Drive System

APPENDIX D: DESIGN FAILURE MODES EFFECTS ANALYSIS

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Our Calculated Operation Point

VW diesel

UQM Generator

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