电驱动铰接式工程车辆操纵稳定性控制分析

铰接式工程车辆因其铰接转向机构布置,使整车行驶过程中的横向稳定性降低。该文针对电驱动铰接式车辆的结构特点,建立了三自由度整车行驶动态数学模型,利用其各轮可独立控制的特性,提出基于直接横摆力矩(direct yaw-moment control,DYC)的车辆稳定性控制策略。分别以前车体质心侧偏角和横摆角速度、后车体质心侧偏角和横摆角速度为控制变量,建立了2种基于不同控制变量下的铰接式车辆最优直接横摆力矩控制策略。通过对地下35t铰接式自卸车的瞬态响应进行仿真分析,从响应速度、精确性等方面,探讨了2种控制策略下铰接式车辆稳定性的实现与性能。该研究可为电驱动铰接式车辆的稳定性控制提供有益的参考。

Analysis of handling stability for electric-driven articulated truck

Abstract: Articulated steering trucks have two separate parts that are connected by an articulation joint. The articulated joint will decrease the lateral stability of truck while it drives at higher speeds. The electric-driven articulated truck discussed in this paper is composed of a diesel engine, generator, rectifier, inverter, and in-wheel-motor, among other components. It is driven by a diesel engine and in-wheel-motor with an AC-DC-AC driving mode. Each wheel of the truck is mounted with one in-wheel-motor, which can be driven independently. All-wheel independent drive systems of articulated trucks have some advantages, such as being space-saving, having a fast driving response time, and having accurate control of the driving forces on each wheel. This paper proposes a direct yaw-moment control (DYC) method to enhance the stability behaviors of articulated vehicles for the each wheel to be controlled independently. The modified 3 DOF vehicle dynamics model is built based on the structural features of the articulated steering truck. The feedforward and feedback controller is designed with the mass center slip angle and yaw angular velocity of the front body and the mass center slip angle and yaw angular velocity of rear body set as separate variables. This approach combines the feedforward compensation for the mass center slip angle and yaw angular velocity, and the feedback compensation based on the deflection of real transient output and ideal output of vehicle to control the vehicle movement. The factors of feedforward and feedback compensation are determined by the optimal control strategy based on a linear quadratic regulator (LQR). The two optimal DYC controllers for the yaw stability of articulated vehicles are designed based on the different control variables. The 35 ton electric-driven articulated dump truck was simulated to verify the effectiveness of DYC control strategy for improving the yaw stability of vehicle. The vehicle dynamics simulation model generated by MATLAB/Simulink software is used to perform a transient step response analysis of articulated trucks. The performance of vehicle stability is compared and analyzed from the aspects of response time and accuracy under the two proposed DYC control methods. The values of yaw angular velocity, mass center side slip angle, and lateral acceleration are used to evaluate the lateral dynamics performance of articulated truck. The computer simulation results show that the two control strategies are feasible and correct. Both of them can realize the control target on enhancing articulated truck stability. The controlling effects of these two DYC methods on the articulated truck are compared from the aspects of yaw rate and mass center slip angle simultaneously. The simulation results suggest that the dynamic stability behavior of articulated trucks with the optimal DYC control acting on the front body is better than that of the optimal DYC control on the rear body.