A FORCE-BASED SUSPENSION MODELLING APPROACH FOR VEHICLE STEADY-STATE HANDLING

This paper presents a modelling procedure for predicting steady-state cornering behaviour of four-wheeled vehicles. The method retains the simplicity of the traditional Kinematic Roll Centre approach, but requires less input data than multi-body simulations using commercial computer programs. The core concept of the method is to model the suspension at each wheel with its equivalent swing-arm by identifying the instant centre between each wheel and the chassis. Then, tyre contact patch forces can be decomposed into two force components, one normal to this swing arm which causes suspension deflection, and the other along the swing arm which transfers directly to the chassis. Using these force components, true chassis positions can be resolved, and accurate tyre forces predicted. The key advantages of this approach are: (1) the contribution of lateral loads to chassis heave is included; (2) a more accurate load transfer prediction result; (3) higher-order tyre effects, such as camber thrust, can be included, and (4) accurate predictions are possible at high levels of lateral acceleration. Significant insight into suspension behaviour also results from studies using this approach.