变时滞间隙非线性机翼颤振主动控制方法

针对当前考虑时滞的机翼颤振主动控制研究多集中在只考虑某一通道存在固定时滞的问题，为解决控制回路前向和反馈通道都可能存在不确定时滞的情况，提出了具有时滞补偿功能的控制方法，实现对双向通道不确定时滞的颤振控制。在控制系统回路传输的数据中附加“时间戳”标志。在反馈通道，考虑系统状态不完全可测，设计时滞补偿状态预估器；在前向通道，提出了基于状态反馈的时滞补偿预测控制器。分析了使用所提时滞补偿策略构成的闭环控制系统的稳定性。以含间隙非线性的翼型为被控对象，对其发生颤振时前向通道和反馈通道存在不确定时滞的颤振控制进行了研究。讨论了不同通道的时滞大小对颤振控制效果的影响。仿真结果表明:所提时滞补偿控制方法能有效抑制颤振，提高系统的稳定性；在控制性能影响上，基于状态反馈的控制方法，其控制效果受反馈通道时滞的影响更大。 

Flutter active control method of time-varying delayed aerofoil with free-play nonlinearity

Nowadays the studies on flutter active control methods considering time delays have been focused on constant time delay in one control channel. However, the time delays in a control loop are maybe time-varying and exist in the forward channel, feedback channel or both. As a result, the control method that can compensate time delay influences was developed and used to realize the flutter control of uncertain time delay for two channels. The trick where "time-stamped" flag was added in the data transferred was proposed. The state predictor with the ability to compensate for the time delays in feedback channel was reconstructed to predict the controlled plant states. The predictive controller using state feedback in a state space form was designed to compensate the delays in the forward channel. Then the stability of the closed-loop control system was analyzed with the above mentioned control strategy. The airfoil with free-play nonlinearity was used in the simulation. Then the flutter active control schemes for controlled system with variable time delays in both forward and feedback channels were investigated. Finally, the effects of time delay size in different channels on flutter control were discussed. The simulation results show that the developed method can suppress the flutter effectively with different time delay in both channels and improve the system stability. From a control point of view, the time delay in the feedback channel may have more influence on the control result when the control method based on the system state feedback is used.