基于区间矩阵的四旋翼无人机鲁棒跟踪控制
Robust tracking control of a quad-rotor UAV via Interval matrix

针对飞行环境不断变化的四旋翼无人机轨迹跟踪问题, 提出了基于区间矩阵的鲁棒跟踪控制策略. 首先, 将四旋翼无人机非线性动态模型解耦为外环位置控制系统和内环角度控制系统. 接着, 考虑到飞行环境变化引起的升力系数、 中高速飞行下不可忽略的阻力系数等参数的不确定性, 引入区间矩阵对内外环系统的系统参数进行描述, 并对内外环控制系统设计鲁棒 H∞反馈控制策略来抑制有界外部扰动. 然后, 根据李雅普诺夫稳定性定理得到了使外环系统指数渐近稳定和内环系统鲁棒渐近稳定且均满足 H∞性能指标的LMI 充分条件,同时, 给出了控制器增益的求解方法. 最后, 仿真及实验结果结果验证了所提方法的鲁棒性,优越性和有效性.
In this paper,the robust tracking control strategies for a quad-rotor unmanned aerial vehicle (UAV) with changing flight environment are put forward based on the interval matrix. Firstly, the nonlinear dynamic model of the quad-rotor UAV is decoupled into the inner loop attitude control system and the outer loop position control system. Next, taking into account the change of the lift coefficient and non-negligible drag coefficient in medium and high speed which is caused by the changing flight environment, the interval matrix is introduced to describe the system parameters of the inter and outer loop system and the robust H∞ feedback control methods are designed to reject the bounded disturbance in the closed inner-outer loop system. Then, according to Lyapunov stability theory, the LMI-based sufficient conditions of exponential asymptotic stability for outer-loop control system and robust asymptotic stability for inter-loop control system are derived. At the same time, the H∞ performance indexes are both satisfied. Meanwhile, the gain matrices of controller are presented. Finally, the effectiveness, advantages and robustness of the proposed method are verified by simulation and experimental results.