A Split Configuration Hybrid Electric Vehicle Model for the Nads

In order to remain on the forefront of driving simulation technology, it is necessary to continually upgrade and expand the capabilities of the NADS. One extension that is suggested by recent trends in the automotive marketplace is the ability to simulate hybrid electric vehicles. Support of hybrid electric vehicles by the NADS is motivated by the engineering and human factors challenges of designing and testing advanced concepts for vehicles and user interfaces. This paper discusses the extension of the vehicle dynamics to include a split hybrid electric four wheel drive power train. The new power train is based on Daimler Chrysler’s Dodge Durango TTR hybrid. The vehicle dynamics subsystem is based on the University of Iowa’s real time recursive dynamics (RTRD). The RTRD enables efficient simulation of general rigid multi-body systems. Additional force generating subroutines are included to model an extensive array of vehicle subsystems, such as power train, steering, brakes, aerodynamics, and tires. The new hybrid power train design includes new electromechanical component models, which are described in detail. A discussion of appropriate applications of the models based on their fidelity is included. Models of electromechanical components can bring with them greater bandwidth requirements. Bandwidth/performance tradeoffs are discussed; and suitable models for driver-in-the-loop simulation are selected. INTRODUCTION The National Advanced Driving Simulator (NADS) will expand the capabilities for human centered driving simulator research in the improvement of vehicle safety and usability as well as the improvement of their efficiency and performance. The large excursion motion base allows the driver to have greater sensitivity to the motion cues of the vehicle. This represents an opportunity for more detailed vehicle design studies as well as a responsibility for accurate, high fidelity vehicle models. The NADS is equipped with four validated vehicle models along with their corresponding cabs. In order to remain on the forefront of driving simulation research, however; it is necessary to continually upgrade its technology and capabilities. It is envisioned that as new vehicle models are added to the NADS library, new cabs will also be acquired and instrumented for use in the simulator. Possible a generic cab with highly configurable dashboard panels would be used for increased flexibility and modularity. One extension suggested by recent trends in the automotive marketplace is the ability to model hybrid electric vehicles. The Toyota Prius and Honda Insight are popular hybrids currently available in the US; and new models are due out from Ford, GM, and Daimler Chrysler in the next couple of years. Support of hybrid electric vehicles by the NADS is motivated by the engineering and human factors challenges of designing and testing advanced concepts for vehicles and user interfaces. This paper discusses the extension of the vehicle dynamics to include a split hybrid electric four wheel drive powertrian. This configuration is based on the Daimler Chrysler Dodge Durango hybrid forecasted for production in 2003 [1]. The hybrid version of the Durango would offer V8 performance with a V6 engine while improving gas mileage by 20%. This split configuration hybrid is called through-the-road (TTR) because the only connection between the electric and gas powered systems is between the tire forces, through the road.