无人驾驶探测车的转向特性分析与仿真

Dynamics Analysis and Simulation of Unmanned Rover Steering Mechanism

无人驾驶探测车是探测行星表面和地下未知世界的重要工具。它所面临的环境非常复杂,转向机构的性能直接关系到探测任务的成败。为了研究六轮探测车的转向特性,该文建立了它的运动模型,按照质心零侧偏角控制策略进行了合理简化。分析了其稳态响应特性;同时得到了质心侧偏角、横摆角速度、侧向加速度与前轮转角的传递函数,在此基础上,对研究的样车进行了前中后轮转角成比例控制的六轮转向车辆的运动学仿真,并与四轮转向和前轮转向进行了对比。结果表明,六轮转向小车的瞬态响应特性更为优越,对提高小车的转向性能非常有利。该结果可为结构设计提供参考。

Unmanned rover is the most useful tool for exploring the planetary surface and unknown world under the ground. Its steering performance is related to whether the exploring work would succeed or not, because the environment facing the rover is very complex. To study its steering capability, a dynamic model of 6 - wheel rover steering system is brought out in this article. Then a simplified model with＇0 - side slip angle＇control strategy is worked out, and the steady characteristics is analyzed. Then the transfer functions of the front wheel steering angel to the side slip angle, yaw rate and side acceleration are generated. Based on them, a kinematic simulation of the sample rover is performed. At last, the difference among the 6WS, 4WS, and 2WS mechanism is presented. As a result, 6WS has more advantages to enhance the rover＇s steering performance. The result could be a reference for designing a rover.