Estimation process for tire-road forces and vehicle sideslip angle

This study focuses on the estimation of car dynamic variables for the improvement of vehicle safety, handling characteristics and comfort. More specifically, a new estimation process is proposed to estimate longitudinal/lateral tire-road forces, sideslip angle and wheel cornering stiffness. This method uses measurements from currently-available standard sensors (yaw rate, longitudinal/lateral accelerations, steering angle and angular wheel velocities). The estimation process is separated into two blocks: the first block contains an observer whose principal role is to calculate tire-road forces without a descriptive force model, while in the second block an observer estimates sideslip angle and cornering stiffness with an adaptive tire-force model. The different observers are based on an Extended Kalman Filter (EKF). The estimation process is applied and compared to real experimental data, notably sideslip angle and wheel force measurements. Experimental results show the accuracy and potential of the estimation process.