基于ICR的履带车辆路径跟踪与转向控制算法研究

针对丘陵山区单边制动农用履带车辆路径跟踪精度低、控制次数多、转向偏差大等问题，本文开展不同负载条件下履带车辆路径跟踪控制研究。首先，对履带车辆的转向运动学进行理论分析，并建立履带车辆运动学模型；其次，根据履带车辆单边制动转向特性，提出一种基于瞬时旋转中心（Instantaneous center of rotation，ICR）的大角度转向控制算法，该算法能够根据规划路径的转向点位置与履带车辆转向瞬心，规划出最优的转向目标点，并控制履带车辆在该转向目标点一次性转向到所需航向，与此同时，完成转向控制器设计；最后，开展履带车辆在3种不同负载条件下的仿真试验与田间试验。仿真结果表明，大角度转向控制算法产生的跟踪路径平均误差面积与平均转向控制次数分别降低68.95%、68.77%；田间试验结果表明，大角度转向控制算法产生的跟踪路径平均横向偏差均值、平均转向控制次数与转向点处平均最小偏差分别减少57.27%、33.93%、62.29%，且路径跟踪效果更优，验证了大角度转向控制算法的有效性。试验结果满足履带车辆路径跟踪的要求，为实现农用履带车辆的路径跟踪提供理论基础与参考。

Path Tracking and Turning Control Algorithm of Tracked Vehicle Based on ICR

Aiming at the problems of low path tracking accuracy, many control times and large turning deviation of unilateral braking agricultural tracked vehicles in hilly and mountainous areas, the path tracking control of tracked vehicles under different load conditions was studied. Firstly, the turning kinematics of the tracked vehicle was theoretically analyzed, and the kinematics model of the tracked vehicle was established. Secondly, according to the unilateral braking turning characteristics of the tracked vehicles, an instantaneous center of rotation was proposed for instantaneous control, which can plan the optimal turning target point, according to the turning point position of the planned path and the turning instantaneous center of the tracked vehicle, and controlling the tracked vehicle to turn to the required course at the turning target point at one time. Meanwhile, the design of the turning controller was completed. Finally, the simulation and field experiments of the tracked vehicle under three different load conditions were carried out. The simulation results showed that the average error area of the tracking path and the average turning control times generated by the large angle turning control algorithm were reduced by 68.95% and 68.77%, respectively. The mean value of the mean lateral deviation of the tracking path, the mean turning control times and the mean minimum deviation of the turning point generated by the large angle turning control algorithm were reduced by 57.27%, 33.93% and 62.29%, respectively. And the path tracking effect was better, which verified the effectiveness of the large angle turning control algorithm. The test results met the requirements of tracked vehicle path tracking and provided a theoretical basis and reference for the path tracking of agricultural tracked vehicles.