基于非线性干扰观测器的飞机全电刹车系统滑模控制设计

飞机防滑刹车具有典型的强非线性、强耦合和参数时变等特点, 并且跑道环境的干扰容易对飞机的地面滑跑性能造成不利影响. 本文提出了一种基于非线性干扰观测器的飞机全电防滑刹车系统滑模控制设计方法. 首先, 考虑了实际刹车不确定性干扰条件下的防滑刹车动力学建模问题, 通过对高阶非线性刹车系统进行反馈线性化处理, 简化了基于严格反馈的模型. 其次, 基于对主轮打滑原因的深入分析, 设计了非线性干扰观测器对干扰进行在线估计, 并在控制律设计中引入补偿部分. 通过构造递归结构的快速终端滑模控制器来跟踪实时变化的最佳滑移率并建立稳定性条件, 实现了飞机全电防滑刹车系统的有限时间快速稳定并有效抑制了主轮锁定打滑. 通过在不同跑道状态下进行模拟仿真, 验证了本文提出的飞机防滑刹车控制策略可以有效地提高刹车效率.

Sliding Mode Control Design of Aircraft Electric Brake System Based on Nonlinear Disturbance Observer

Aircraft antiskid braking has typical characteristics of strong nonlinearity, strong coupling and time-varying parameters, and the disturbance of runway environment is easy to adversely affect the ground running performance of the aircraft. In this paper, a nonlinear disturbance observer-based sliding mode control design method is proposed for the aircraft electric antiskid braking system. Firstly, the dynamic modeling problem of antiskid braking under the disturbance of actual braking uncertainty is considered. The model based on strict feedback is simplified in the light of feedback linearization of the high-order nonlinear braking system. Secondly, based on the in-depth analysis of the main wheel slip, a nonlinear disturbance observer is designed to estimate the disturbance online, and the compensation part is introduced into the control law design process. A fast terminal sliding mode controller with recursive structure is constructed to track the optimal sliding rate changing in real time and the stability conditions have been established. The finite-time stability of the aircraft all-electric antiskid braking system is realized and the locking slip of the main wheel is effectively suppressed. Simulation results show that the antiskid braking control strategy proposed in this paper can effectively improve braking efficiency.