农用拖拉机的自适应二阶滑模路径跟踪控制

Adaptive Second-Order Sliding Mode Path Tracking Control for Agricultural Tractors

中文关键词  路径跟踪  二阶滑模  自适应控制  农用拖拉机  鲁棒精确微分器  有限时间稳定性

英文关键词  Path tracking, second-order sliding mode, adaptive control, agricultural tractors, robust exact differentiator, finitetime stability

中文摘要

      针对农用拖拉机在未知扰动影响下的路径跟踪控制问题, 本文提出了基于自适应二阶滑模和扰动观测技术的路径跟踪控制策略.首先, 建立含有未知扰动项的路径跟踪偏差模型, 通过利用自适应控制和改进的加幂积分技术, 构造自适应二阶滑模路径跟踪控制方法, 该控制方法削弱了滑模控制中存在的抖振影响.其次, 为了解决大扰动下控制增益调整过度的问题, 通过将鲁棒精确微分器和自适应二阶滑模控制结合, 构造复合的路径跟踪控制方法. 严格的Lyapunov分析表明横向偏差和航向偏差均在有限时间内稳定到原点.最后, 仿真结果验证了本文设计的制导方法能够保证农用拖拉机能快速且稳定地跟踪上任意弯曲的参考路径.

英文摘要

      In this paper, the path tracking control strategies are proposed based on adaptive second-order sliding mode control (SOSM) and disturbance observer techniques to solve the path tracking problem of agricultural tractors under the influence of unknown disturbances. First of all, a path tracking offset model with unknown disturbance is established, and an adaptive SOSM path tracking control method is constructed by using adaptive control and the revamped adding a power integrator techniques, which reduces chattering effects existing in sliding mode control. To solve the problem of excessive adjustment of control gains under large disturbances, then, by combining the robust exact differentiator with the derived adaptive SOSM controller, the composite path tracking control method is also constructed. The strict Lyapunov analysis confirms that the lateral deviation and the heading deviation can be finite-time stabilized to the origin. Finally, the simulation results confirm that the designed guidance approach can ensure that the agricultural tractor can track the arbitrary reference path quickly and stably.