针对四轮独立转向/驱动车辆的转向稳定性问题，提出一种基于直接横摆力矩的滑模变结构控制算法． 根据 Ackerman 转向模型计算车辆前后轮转向角之间的关系，并根据零质心侧偏角控制目标计算车辆各轮的转向角;设计以横摆角速度和质心侧偏角为控制目标的滑模变结构控制算法，对各轮转向角和驱动力矩进行控制． 运用 Lyapunov 方法证明了该算法的稳定性，最后利用 Matlab/Simulink 仿真软件对控制算法进行仿真分析．结果表明，该控制算法可以将质心侧偏角和横摆角速度控制在理想范围内，从而有效提高车辆转向稳定性．

Aiming at the steering stability of four-wheel-steering/driving vehicles，an sliding mode variable structure control algorithm is proposed based on the direct yaw moment． First，the relationship between the steering angles of frontand rear wheels is calculated through the Ackermann steering model，and all these angles are also calculated according to the control target of a zero sideslip angle． Then，the sliding mode variable structure control algorithm with the yaw rate and the sideslip angle as the control targets is designed to control the steering angle and driving torque of each wheel． Finally，the stability of the proposed control algorithm is proved by means of the Lyapunov method，and the software Matlab/Simulink is used to analyze the proposed control algorithm． Simulation results show that the proposed control algorithm can maintain the sideslip angle and the yaw rate within ideal ranges，and thus the steering stability of vehicles is effectively improved．