Abstract:

The existing differential control strategies for the articulated dump truck with six electric wheels can simply achieve differential velocity.Moreover,they ignore yaw control and acceleration slip regulation,which causes the whole truck to show a poor dynamic performance.In order to solve these problems,a differential control strategy on the basis of the hierarchical control of driving force is proposed.Firstly,a dynamic mathematical model of the whole truck containing longitudinal,lateral,yaw and roll degrees of freedom is derived on the basis of Lagrange equation method.Then,the differential control strategy on the basis of the hierarchical control of driving force is designed,which is composed of the decision layer for total driving power and yaw control power,the distribution layer for differential drive and the stability layer for acceleration slip regulation.Finally,active disturbance rejection control algorithm is used to calculate the needed yaw control power to eliminate steering angle deviation,and optimal slip ratio recognition algorithm is used to amend the driving power of each wheel.The offline simulation results show that the proposed strategy can better realize the differential velocity of each wheel under different working conditions on the roads of different adhesion coefficients,and it can ensure better steering performance of the whole truck and better stability of each wheel.

Key words: articulated dump truck, electric wheel, differential control strategy, hierarchical control, active disturbance rejection control, offline simulation