Vehicle Dynamics Simulation with Inclusion of Freeplay and Dry Friction in Steering System

The paper presents mathematical models and simulation studies of a car handling with regard the freeplay (backlash, clearance) and friction (viscous and dry friction with stiction) in a steering system. For description of these principal non-linearities in equations of motion a new method (basing on two piecewise-linear projections luz(…) and tar(…) as well as their special mathematical apparatus) has been used. Simulation models describe lateral dynamics of a passenger car with typical steering system including the freeplay and friction. Three types of open-loop car tests (parking like, lane change and sinusoidal test) have been used in the simulation. Some examples of results are presented. They show a sensitivity of car dynamics processes on the freeplay and friction in the steering system.