Development and evaluation of torque distribution methods for four-wheel independent-drive electric vehicle based on parameter estimation

Zheming Chen,Jianghua Fu,Bao Chen,Bohan Zhang

doi:10.1177/1687814019847405

Abstract

A hierarchical controller including a vehicle condition parameter estimator for improving the vehicle stability is theoretically applied to a four-wheel independent-drive electric vehicle. This stu...

Highlights

A four-wheel independent-drive (4WID) electric vehicle represents an innovative design in which four in-wheel motors are used to drive the wheels independently
The torque distribution was achieved through three mathematical optimization methods, and the independent control of the four drive wheels was achieved such that the vehicle effectively retains its handling stability even under highspeed or low road friction coefficient conditions
It is more straightforward to estimate the probability density distribution of nonlinear functions than the nonlinear function itself,13 and we designed our According to the vehicle model, the magic formula tire model14 and tire vertical force formula comprise the estimator state equation [7], and the measurement equation [8], shown below v_x = vyg +

Summary

Introduction

A four-wheel independent-drive (4WID) electric vehicle represents an innovative design in which four in-wheel motors are used to drive the wheels independently. We established a vehicle condition parameter estimator, an active yaw moment controller, and a torque distribution controller to support better handling stability. The active yaw moment control layer adopts a SMC method to obtain the additional yaw moment necessary to maintain the handling stability of the vehicle by the joint control of the sideslip angle and yaw rate This additional yaw moment is used alongside the generalized longitudinal force demand as the constraint condition under which the tire utilization rate serves as the objective function. The torque distribution was achieved through three mathematical optimization methods, and the independent control of the four drive wheels was achieved such that the vehicle effectively retains its handling stability even under highspeed or low road friction coefficient conditions. It is more straightforward to estimate the probability density distribution of nonlinear functions than the nonlinear function itself, and we designed our According to the vehicle model, the magic formula tire model and tire vertical force formula comprise the estimator state equation [7], and the measurement equation [8], shown below

À 2 Max

Objective function

Objective function solution

Conclusion

Method