ADVANCED VEHICLE TECHNOLOGIES

FOR EFFICIENT POWERTRAIN PERFORMANCE

Final Report KLK420 N06-14

National Institute for Advanced Transportation Technology University of Idaho

November 2006

Edwin Odom; Steven Beyerlein; Jason Sagen; Lloyd Gallup

DISCLAIMER

The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the information presented herein. This document is disseminated under the sponsorship of the Department of Transportation, University Transportation Centers Program, in the interest of information exchange. The U.S. Government assumes no liability for the contents or use thereof.

1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No.

5. Report Date

January 2006

4. Title and Subtitle Advanced Vehicle Technologies for Efficient Powertrain Performance

6. Performing Organization Code

KLK420 5.Author(s) Edwin Odom; Steven Beyerlein; Jason Sagen; Lloyd Gallup

8. Performing Organization Report No.

N06-14 9. Performing Organization Name and Address

National Institute for Advanced Transportation Technology University of Idaho

10. Work Unit No. (TRAIS)

PO Box 440901; 115 Engineering Physics Building Moscow, ID 838440901

11. Contract or Grant No.

DTRS98-G-0027 12. Sponsoring Agency Name and Address

US Department of Transportation Research and Special Programs Administration

13. Type of Report and Period Covered

Final Report: Sept. 03-July 06

400 7th Street SW Washington, DC 20509-0001

14. Sponsoring Agency Code

USDOT/RSPA/DIR-1 Supplementary Notes:

16. Abstract

Over the last decade, vehicle projects in our capstone design courses have progressively required more sophisticated design and manufacturing processes. At the same time, the general population of engineering students has less hands-on shop experience than their predecessors, the number of required manufacturing-oriented courses has decreased, and the complexity of tools used for detailing designs and handling materials have become more specialized. To remedy this situation, we have implemented a learner-centered approach for creating just-in-time resources that support project learning about vehicle systems. These are housed in an innovative design laboratory known as Mindworks. This project combined efforts of undergraduate students in technical elective courses as well as graduate student mentoring of design projects and thesis work surrounding state-of-the-art structural optimization and geartrain design.

17. Key Words

Laboratory; education and training materials; competition; design methods; transmissions; gears; structural models

18. Distribution Statement

Unrestricted; Document is available to the public through the National Technical Information Service; Springfield, VT.

19. Security Classif. (of this report)

Unclassified

20. Security Classif. (of this page)

Unclassified

21. No. of Pages

9

22. Price

…

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

Advanced Vehicle Technology for Efficient Powertrain Performance page i

Table of Contents INTRODUCTION .............................................................................................................. 2

DESCRIPTION OF PROBLEM......................................................................................... 3

APPROACH AND METHODOLOGY ............................................................................. 4

Literature Review............................................................................................................ 4

MindWorks Laboratory .................................................................................................. 5

Reverse Engineering ....................................................................................................... 5

FINDINGS; CONCLUSIONS; RECOMMENDATIONS................................................. 7

Advanced Vehicle Technology for Efficient Powertrain Performance page 1

INTRODUCTION

This project furthers development of advanced vehicle technologies that when combined can make significant progress toward improving powertrain performance by completing three activities:

1. Conducting a literature search of existing hybrid transmission designs which lead to a solid model prototype of a hybrid transmission.

2. Creating a special laboratory named MindWorks to house physical artifacts that

teach the subtly of design through hands-on experience as well as provide just-in-time online resources for design and manufacturing.

3. Reverse engineering a sophisticated motorcycle transmission design and

reassemble components into a configuration very different from the original design.

We began with a comprehensive literature review to determine the most current thinking on hybrid drive trains. Attention was then given to identify a process that could enable NIATT researchers to make evolutionary improvements to these designs. This requires a method to provide current and prospective graduate students with professional development in design analysis and advanced manufacturing methods. To further this goal, a new laboratory called MindWords was developed. The laboratory immerses users in the subtleties of machine design, helping them use hybrid drivetrain components in novel ways and in combinations not imagined by their original designers.

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DESCRIPTION OF PROBLEM

In today’s rapidly changing world, state-of-the-art approaches to design and just-in-time methods for learning relevant tools, techniques, and technologies are in great demand. For many organizations, especially universities, this problem is accentuated by a large annual turnover of those who participate in research and development. An approach to knowledge transfer that integrates physical, virtual and human elements is likely to be most effective with a broad spectrum of learner/practitioners. This begins with programs for training mentors and technical advisors in new technology areas. It can be enriched through special environments where knowledge resides in an easily accessible format that is regularly updated and expanded through efforts of a broad community. Soaring gas prices and increased emissions regulations have led to the need for higher efficiency vehicles. In this regard, hybrid vehicles provide promising research because they combine internal combustion engines with electric drive systems to create a system that burns less fuel, has lower emissions, and has as much power as standard vehicle. To get the most efficiency out a hybrid system, it needs to be lightweight, properly sized and durably designed. Lightweight systems demand lightweight materials, lightweight power sources, and lightweight electronics. A perfect test bed for these hybrid systems is the Hybrid Formula SAE (Hybrid FSAE) competition. The Hybrid FSAE is a global collegiate competition sponsored by the Society of Automotive Engineers (SAE) that requires a school to design a small formula style racecar, encouraging the development of high efficiency, lightweight hybrid drive systems.

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APPROACH AND METHODOLOGY

Literature Review The two main types of hybrid drive systems, series and parallel, are illustrated in Fig. 1. In a series drive, an internal combustion engine drives a generator. The generator charges a power storage system (usually batteries or ultra capacitors). The power storage system provides electricity for an electric motor that directly powers the vehicle.

IC Engine

Gen.

E. Mot.

IC Engine

Gen.

Power Storage Power Storage

E. Mot.

Series Hybrid Parallel Hybrid

Figure 1 Series vs. parallel system.

A parallel drive system differs from a series drive system in that the vehicle can be driven by the electric motor, by the internal combustion engine, or a combination. Since both the engine and the electric motor can drive the vehicle together when high power is required, neither of the systems needs to be as large as that for a series hybrid. This means the entire package can be smaller and lighter, and add to the overall efficiency of the vehicle. One challenge of a parallel drive system is how to split the power from the internal combustion engine, to provide power for both the generator, and the wheels, and how to get power from the electric motor back into the system. One way to accomplish this is to use a planetary gear setup. A planetary gear setup allows for multiple power inputs and multiple combinations of power outputs. Another key issue with hybrid drive systems is power storage. Mechanical power from the internal combustion engine is converted to electric power via one or more generators.

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The generators must store the electric power for use in the electric motors. The two main power storage systems are batteries and ultra capacitors. Most current hybrid vehicles use a Nickel Metal Hydride (NiMH) battery. NiMH batteries allow for more charge/discharge cycles than standard lead-acid batteries. Ultra capacitors also have potential for use in a hybrid drive system. They are lighter than batteries, have much higher charge and discharge capacities, and charge and discharge quickly. Unfortunately the current technology in ultra capacitors does n0t allow for as much energy storage (energy density per unit weight) as with standard batteries.

MindWorks Laboratory This laboratory was created to support just-in-time learning about machine design and local manufacturing capabilities that are frequently used in capstone design projects. The laboratory includes a physical space, working prototypes, software tools, and a rich library of on-line resources about various machine components and shop practices. Resources for just-in-time learning include posters for small group research, TK Solver models for design analysis, and videos of alternative fabrication practices. Background about this laboratory and the resources that have been created can be found on the web at www.webs1.its.uidaho.edu/ele/Mindworks. A natural extension of laboratory is design resources for sub-systems commonly found on transportation platforms. This work has cultivated machine design expertise among undergraduate students on vehicle design teams as well as among graduate student members of the Idaho Engineering Works.

Reverse Engineering A two-month mini-project was undertaken in an Advanced Machine Design Elective to reverse engineer a Honda 600 motorcycle engine transmission, redeploying this in a FSAE vehicle. This involved the complete dismantling, measuring various components, studying the coolant flow, and modeling the oil galleys. Special attention was given to understanding where the designers had reduced weight and/or combined functions. Then the engine and transmission internals were rearranged into a new output configuration shown in the Figure 2.

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Figure 2 New Honda engine and transmission configuration.

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FINDINGS; CONCLUSIONS; RECOMMENDATIONS

The initial phase of this research project was a review of current, past, and emerging hybrid technologies. The Hybrid FSAE rules dictate that the internal combustion motor must be smaller than 250cc. and that the drive train be powered by both mechanical and electric drive components. The frame and safety requirements must meet all FSAE requirements. The rules along with the literature review led to several design possibilities. The current design will be similar to the system used on the Toyota Prius. It uses a planetary “power split device” to direct power from internal combustion engine and electric motors. Figure 3 shows a power schematic of the device.

R

C

S

M/G2

I.C.E

Power Storage

M/G1

R=Ring Gear C=Planet Carrier S=Sun Gear I.C.E.=Internal Comb. Engine M/G1=Generator M/G2=Electric Motor

Figure 3 Power schematic.

The power split device uses two electric motor/generators and a 250cc. 4-stroke engine to power the vehicle. M/G1 can be used as a generator or an electric motor. It is primarily a generator but for high torque requirements it can act as a motor. M/G2 is also a generator/motor but is used primarily as an electric motor. Under light torque requirements it can act as generator and charge the power storage device. The initial power split device solid model is illustrated in Fig. 4.

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Figure 4 Power Split Device

We are currently exploring the use of ultracapacitors for power storage. At the competition, the car will do several driving events, the longest and most important of which is the endurance event. The endurance event consists of several laps on a road course. This will require the car to accelerate and decelerate multiple times in a short span of time. This type of driving seems to lend itself perfectly to ultra capacitors. Ultra capacitors allow for quick discharge at peak torque requirements, when the car is accelerating rapidly, and quick recharge rates when the car is decelerating rapidly. Ultra capacitors are also smaller and easier to fit into a small frame than batteries.

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