Search Results

Vehicle electrification is being actively expanded into coming generations of passenger and commercial vehicles. This technology trend is helping vehicles to become more energy efficient. For electric vehicle (EV) city bus application, the system designers have been experimenting with a number of options including direct drive and multi-speed gearbox architectures. Direct drive scenario offers simplified drivetrain system, however requires a large and powerful electric motor. Multi-speed transmission system provides an opportunity to reduce motor size and optimize its operating points, but increases complexity from the architecture and controls point of view. This paper provides an overview of several common system layouts and examines their advantages and disadvantages. Vehicle simulation results are presented to compare direct drive vs. multi-speed technology from the gradeability, acceleration and energy consumption points of view.

Commercial vehicle operators and governments around the world are looking for ways to cut down on fuel consumption for economic and environmental reasons. Two main factors affecting the fuel consumption of a vehicle are the drive route and the driver behavior. The drive route can be specified by information such as speed limit, road grade, road curvature, traffic etc. The driver behavior, on the other hand, is difficult to classify and can be responsible for as much as 35% variation in fuel consumption. In this work, nearly 600,000 miles of drive data is utilized to identify driving behaviors that significantly affect fuel consumption. Based on this analysis, driving scenarios and related driver behaviors are identified that result in the most efficient vehicle operation. A driver assistance system is presented in this paper that assists the driver in driving more efficiently by issuing scenario specific advice.

This book provides a broad and comprehensive look at hybrid powertrain technologies for commercial vehicles. It begins with the fundamentals of hybrid powertrain systems, government regulations, and driving cycles, then provides design guidelines and key components of hybrid powertrains for commercial vehicles. It was written for vehicle and component engineers and developers, researchers, students, policymakers, and business executives in the commercial vehicle and transportation industries to help them understand the fundamentals of hybrid powertrain technologies and market requirements for commercial vehicles. It is useful for anyone who designs or is interested in hybrid powertrains and their key components. The term ‘commercial vehicle’ applies to everything from light delivery vehicles to class 8 long haul trucks, buses, and coaches. These vehicles are used for a wide range of duties, including transporting goods or people and infrastructure service.

Electrification and hybridization show great potential for improving fuel economy and reducing emission in heavy-duty vehicles. However, high battery cost is unavoidable due to the requirement for large batteries capable of providing high electric power for propulsion. Presenter Tae-Kyung Lee, Univ. of Michigan

Current concerns about climate change, energy security and record high oil prices have triggered high enthusiasm and push for plug-in vehicles. Widespread adoption of plug-in vehicles would result in significant reductions in CO2 emissions from transportation. It would also reduce our dependence on fossil fuels by replacing petroleum-sourced energy with renewable, domestically produced electricity. While a few OEMs have successfully launched hybrid vehicles and even toyed with plug-in hybrid solutions in the passenger car market segment, little attention has been placed on heavier commercial vehicles. Large utilities operate fleets of several hundred diesel-power trouble trucks to repair and maintain their transmission and distribution infrastructure. Medium-duty segment is over a million vehicles annually. These vehicles are typically driven in densely populated neighborhoods.

Eaton has been working on technologies for cost effective, reliable and safe Automated Mechanical Transmissions (AMTs) since the mid 1970's. The company has introduced three different systems since the late 1980's, but all three systems were constrained by the lack of precise engine speed control during shifting. With the advent of electronic engine controls the constraint has been removed and precise engine speed control during shifting can be easily accomplished. The result is a simplified system that is powerfully intelligent and fully capable of automatic shifting i.e., the transmission system determines when to shift and executes the shift without any driver inducement across the broad spectrum of truck usage. This paper discusses some of the AMTs available to the truck market, showing how the system benefits both the OEM and the end user.

A part-task simulator has been developed which concentrates on the functions related to transmission gear shifting in heavy duty trucks. By avoiding the complexity of full-feature simulators, a simple and cost-effective tool has been produced which allows training of the driver and study of the powertrain in a controlled environment. The components and operation of this new simulator are described, along with present and potential applications.