This paper takes the motor drive travelling system of vehicles as research object. Addressing the disturbance derived from complex pavement and nonlinearity of system during walking and combined the characteristics of the mathematical model of hydraulic travelling system, a disturbance observer based on exponential convergent is designed on the conditions of the vehicle drives at low speed. It can estimate disturbances online and feedforward compensate to the control system. Then a sliding mode control strategy is used to motor speed control system. The simulation model of valve controlled motor system is carried out through MATLAB/Simulink platform. Compared of the result between the proportion integral differential (PID), sliding mode control (SMC) and sliding mode control (SMC) + disturbance observer (DOB), the oscillation and overshoot of step response on SMC are decreased obviously. When the slow time-varying torque disturbance is added on to evaluate the effects of disturbance observer induced on the SMC, the disturbance value can estimate precisely and deduce influence of motor speed. It improves the SMC + DOB control accuracy and made the vehicle travel on the complex pavement more smoothly.

本文以车辆电机驱动行驶系统为研究对象。针对复杂路面和行走过程中系统的非线性带来的扰动，结合液压行走系统数学模型的特点，针对车辆低速行驶的工况，设计了基于指数收敛的扰动观测器。它可以在线估计扰动并对控制系统进行前馈补偿。然后采用滑模控制策略对电机速度控制系统进行控制。通过MATLAB/Simulink平台建立了阀控电机系统的仿真模型。比例积分微分（PID）、滑模控制（SMC）和滑模控制（SMC）+扰动观测器（DOB）的结果对比，SMC阶跃响应的振荡和超调明显减小。当加入慢速时变扭矩扰动来评估扰动观测器对SMC引起的影响时，扰动值可以精确估计并推断出电机速度的影响。提高了SMC+DOB控制精度，使车辆在复杂路面上行驶更加平稳。