Vehicle Anti-Skid Control by Means of Extended State Observer and Active Disturbance Rejection Controller

When the driving road surface condition suddenly changes from dry to wet, the driving wheels will slip due to much lower coefficient of friction, and thus cause the vehicle to skid. Unlike the popular anti-brake system which applies differential braking to wheels, the presented ant-skid Control properly distributes torques to wheels without braking. In comparison with many recently developed anti-skid control systems, the presented ant-skid control scheme does not require the knowledge of the does not require knowledge of the exact vehicle model, and can reject disturbance and unknown dynamics. More specifically, the anti-skid control is achieved by employing Extended State Observer (ESO) and Active Disturbance Rejection Control (ADRC) algorithm that treats any discrepancy between the exact and the unknown nonlinear or time-varying plant as disturbance to be estimated and rejected The objective of the anti-skid control is to control the vehicle’s yaw motion at the center of mass by closely following the desired yaw rate regardless of cornering or road surface condition. The simulation results show that the anti-skid control is very effective in maintaining the vehicle stability during cornering on a split-μ road surface (i.e. the left side on dry surface, while the right side on icy surface). Keywords-Extended state observer; Anti-skid control; Active disturbance rejection control