基于级联式控制策略的农业机械鲁棒自适应路径跟踪控制

Robust Adaptive Path Tracking Control of Agricultural Machines Based on Cascaded Control Strategy

在机具负载和外部干扰的影响下,农业机械的横摆角速度动力学特性会发生变化,从而导致基于位置偏差控制方法的路径跟踪性能变差.为此,提出一种基于级联式控制策略的鲁棒自适应路径跟踪控制方法.该方法将路径跟踪控制分解为横向位置控制和横摆角速度控制两个级联的控制任务来完成.在横向位置控制中,根据横向位置偏差和航向偏差,采用模糊自适应纯追踪模型确定农业机械期望的横摆角速度;在横摆角速度控制中,提出一种鲁棒自适应控制方法,使农业机械在机具负载变化或者受到外部干扰时,仍然保证横摆角速度具有期望的响应性能.仿真实验和实际的农业机械实验结果验证了所提出方法的有效性和优越性.

Yaw rate dynamics of agricultural machines will change under the influence of implement loads and external disturbances, and thus the path tracking performance of position error-based control methods deteriorates. For this reason, a robust adaptive path tracking control method based on cascaded control strategy is proposed. By this method, the path tracking control task is decomposed into two cascaded control tasks which are the lateral position control task and the yaw rate control task. In the former task, the desired yaw rate of the agricultural machine is determined by utilizing fuzzy adaptive pure pursuit model according to the lateral position error and the heading error. In the latter one, a robust adaptive control method is developed to guarantee that yaw rate has the desired response performance even if the agricultural machine suffers from the implement load variations and the external disturbances. The effectiveness and the superiority of the proposed method are verified by a series of simulation experiments and actual agricultural machine experiments.