Ding Chen, Ding Shihong, Wei Xinhua, Mei Keqi
School of Agricultural Engineering, Jiangsu University, Zhenjiang, Jiangsu, 212013, China; College of Information Engineering, Fuyang Normal University, Fuyang, 236041, China.
School of Electrical and Information Engineering, Jiangsu University, Zhenjiang, Jiangsu, 212013, China.
ISA Trans. 2022 Nov;130:389-398. doi: 10.1016/j.isatra.2022.03.019. Epub 2022 Mar 25.
In the work, the path tracking control methods are developed for autonomous agricultural tractors subject to wheel slip constraints by using second-order sliding mode (SOSM) and finite-time disturbance observer (FDOB) techniques. First of all, the path tracking error dynamics derived from the kinematic model is given and applied to controller design. In order to deal with the inevitable chattering problem existing in the conventional first-order sliding mode (FOSM) controller, a SOSM controller is constructed by regarding the controller derivative as the new control law, which means that the practical control law can be seen as an integration of the SOSM controller. Through a combination of the FDOB and the designed SOSM controller, the composite path tracking controller is further constructed to avoid high control gains in the designed SOSM controller. The strict Lyapunov stability analysis is carried out to ensure that the sliding variable can be finite-time stabilized to the origin under the proposed control algorithms. Finally, the comparative simulation results confirm that the developed guidance laws can achieve good tracking performance and strong robustness even in the presence of slipping effects.
在这项工作中，通过使用二阶滑模（SOSM）和有限时间干扰观测器（FDOB）技术，为受车轮打滑约束的自主农用拖拉机开发了路径跟踪控制方法。首先，给出了从运动学模型导出的路径跟踪误差动态方程，并将其应用于控制器设计。为了解决传统一阶滑模（FOSM）控制器中不可避免的抖振问题，将控制器导数视为新的控制律来构建SOSM控制器，这意味着实际控制律可视为SOSM控制器的积分。通过将FDOB与设计的SOSM控制器相结合，进一步构建复合路径跟踪控制器，以避免设计的SOSM控制器中出现高控制增益。进行了严格的李雅普诺夫稳定性分析，以确保在所提出的控制算法下，滑模变量能够在有限时间内稳定到原点。最后，对比仿真结果证实，所开发的制导律即使在存在打滑效应的情况下也能实现良好的跟踪性能和强大的鲁棒性。
