Simplified Analysis of the Steady-State Turning of Complex Vehicles

SUMMARY The classic analysis of the steady-state turning of the motor vehicle is based on a simple vehicle model in which lateral acceleration is the only motion variable that affects tire slip angles. This paper examines a more complex vehicle whose slip angles depend on lateral acceleration plus another motion variable. Trucks with multiple, nonsteering rear axles are one example of the complex vehicle. A general analysis of the complex vehicle together with analyses of linear and nonlinear trucks provide new insights into the understeer/oversteer quality of all vehicles. It is shown that a complex vehicle can be represented as a simple vehicle with an equivalent wheelbase. A physical interpretation of equivalent wheelbase for trucks and a method for its measurement are presented.