Search Results

This paper describes a low cost, PC based driving simulation that includes a complete vehicle dynamics model (VDM), photo realistic visual display, torque feedback for steering feel and realistic sound generation. The VDM runs in real-time on Intel based PCs. The model, referred to as VDANL (Vehicle Dynamics Analysis, Non-Linear) has been developed and validated for a range of vehicles over the last decade and has been previously used for computer simulation analysis. The model's lateral and longitudinal dynamics have 17 degrees of freedom for a single unit vehicle and 33 degrees of freedom for an articulated vehicle. The model also includes a complete drive train including engine, transmission and front and rear drive differentials, and complete, power assisted braking and steering systems. A comprehensive tire model (STIREMOD) generates lateral and longitudinal forces and aligning torque based on normal load, camber angle and horizontal (lateral and longitudinal) slip.

This paper describes validation work carried out for two vehicle dynamics computer simulation programs. One program, referred to as VDANL (Vehicle Dynamics Analysis NonLinear), is intended to simulate passenger cars, vans and light trucks. The second program simulates All Terrain Vehicles (ATVs) and is referred to as NLATV (NonLinear ATV). The programs have been checked out and validated for a variety of maneuvering conditions and a broad range of vehicles. The programs run on IBM-PC/MS DOS compatible computers, and numerical methods have been used to give numerically stable solutions with reasonable computational speed over a broad range of maneuvering situations.

All Terrain Vehicle (ATV) lateral/directional handling and stability is predominantly affected by tire and load transfer characteristics, and the lack of a rear axle differential. The combined effect of these characteristics are surveyed in this paper through the use of steady state analysis and simple linear dynamic analysis over a range of vehicle characteristics and maneuvering conditions. Computer analysis results are also compared with field test data obtained with instrumented vehicles.

This paper reviews the development and application of a computer simulation for simulating ground vehicle dynamics including steady state tire behavior. The models have been developed over the last decade, and include treatment of sprung and unsprung masses, suspension characteristics and composite road plane tire forces. The models have been applied to single unit passenger cars, trucks and buses, and articulated tractor/trailer vehicles. The vehicle model uses composite parameters that are relatively easy to measure. The tire model responds to normal load, camber angle and composite tire patch slip, and its longitudinal and lateral forces interact with an equivalent friction ellipse formulation. The tire model can represent behavior on both paved and off-road surfaces. Tire model parameters can be automatically identified given tire force and moment test data.

All Terrain Vehicles (ATVs) have unique design features, including low pressure tires, a solid rear axle (i.e., no differential), and a relatively high center of gravity compared to wheel track width, that exert significant influence on their lateral/directional handling and stability properties. In addition, rider weight is a reasonable proportion of vehicle weight and weight shift is used as an additional control means in combination with steering, throttle and braking. This paper describes a nonlinear, time domain simulation analysis of the transient lateral/directional response properties of ATVs with rider control. The simulation is derived from earlier automotive applications. A description of the analytic model and computer simulation are given along with validation comparisons of instrumented vehicle field test data and computer simulation runs.