Tire Force Allocation with Different Vertical Load Estimation Methods for 4WID-4WIS Vehicles

This article develops and compares 5 different vertical load estimation methods for tire force allocation of 4-wheel independent driving and steering (4-sWID-4WIS) vehicles. After calculating the upper demanded force using sliding mode control and PID control, a tire force allocation controller is developed to distribute driving/braking torques utilizing different vertical load estimation methods. Fixed radius circle, double lane change and collision avoidance scenarios are simulated through Simulink/Carsim joint-simulation. Simulation results show that the estimation accuracy of suspension displacement considering load transfer method is the best, and the estimation accuracy will affect tire utilization and future influence the 4WID-4WIS vehicles’ handling and stability performance.