4WD Vehicle Road Adhesion Coefficient Estimation Method Based on Adaptive Filter
The key of developing advanced chassis control strategy was road adhesion coefficient of distributed drive vehicle.How-ever,tire parameters exercised great influence on the estimation of road adhesion coefficient.Therefore,in order to improve the ac-curacy of adhesion coefficient estimation,the method of 4WD vehicle road adhesion coefficient estimation based on self-adaptive filter considering tire parameters was proposed.Based on HSRI tire model and 3DOF vehicle model,the estimation model of 4WD vehicle road adhesion coefficient was developed based on extend kalman filter theory.Aiming at the improvement of the ac-curacy of algorithm estimation,an self-adaptive fuzzy regulator with EKF parameters was designed and the changes of tire radi-us was as the input of the regulator.Self-adaptive tuning of estimation of road adhesion coefficient was achieved by real-time ad-justing measurement noise.Experiments were carried out to verify the reliability of the algorithm and simulation analysis was used under double lane low road and joint road.The results showed that compared with EKF algorithm,the accuracy of the self-adaptive algorithm estimation was improved by 17.2%under double lane low adhesion road and round 35.7%under joint road respectively.The simulation results provided a theoretical basis for the accurate torque distribution of distributed drive vehicle.