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针对存在参数摄动、外部干扰的航空发动机不确定性分布式控制系统,在系统具有时变输入时延和干扰上界未知的情况下,设计了具有鲁棒性能的自适应滑模控制器。基于预测控制和矩阵奇异值理论,对初始的发动机离散分布式模型进行等效线性变换,得到不显含时延项的规范形系统模型,便于进行滑模面参数的求解;在给定的H_∞指标下,推导了滑模运动在非匹配不确定性作用下渐进稳定的充分条件,给出了线性矩阵不等式(LMI)形式的滑模面参数设计方法;最后,设计对干扰具有估计功能的自适应率,在此基础上提出自适应滑模控制器。仿真结果表明:所设计的控制器能够有效降低外部干扰对系统动态性能的影响,在所考虑的不确定性因素作用下,系统的滑模运动具有理想的H_∞性能。当外部干扰强度变化时,控制器的鲁棒性较好,状态收敛时间小于0.8s,且不存在抖振。
Aiming at the uncertain distributed control system of aeroengine with parameter perturbation and external disturbance, an adaptive sliding mode controller with robust performance is designed under the condition that system has time-varying input delay and unknown upper bound of interference. Based on the predictive control and the matrix singular value theory, the initial discrete model of the engine is equivalently transformed linearly to obtain a canonical shape system model that does not contain any delay term, so as to facilitate the solution of the sliding surface parameters. For a given H_ ∞, the sufficient conditions for the sliding mode motion to be asymptotically stable under the mismatch uncertainty are derived, and the design method of sliding mode parameters in the form of linear matrix inequalities (LMI) is given. Finally, the design has the function of estimating the interference Adaptive rate, based on which an adaptive sliding mode controller is proposed. The simulation results show that the designed controller can effectively reduce the influence of external disturbances on the system dynamic performance, and the sliding mode motion of the system has the ideal H_∞ performance under the consideration of the uncertainties. When the external disturbance intensity changes, the robustness of the controller is better, the state convergence time is less than 0.8s, and there is no chattering.