基于时滞LQR算法的风洞模型振动控制试验研究

Research on Experiment of Vibration Control of Wind Tunnel Model Based on Time-delay LQR Algorithm

为有效抑制风洞试验中飞行器模型的振动,利用气动力学与机械动力学的观点分析了风洞模型的振动原因及特点,并建立了风洞模型—测力天平—风洞支杆所组成的悬臂梁系统的二阶模型。针对飞行器模型振动控制中的时滞问题,分析了时滞现象产生的原因及对风洞试验飞行器模型振动控制的影响,并利用基于所测振动信号与作动器信号的基频傅里叶变换方法实现了基频处的时滞量辨识。基于辨识出的时滞量分别分析研究考虑时滞问题与未考虑时滞问题的风洞模型振动控制状态方程,并设计时滞补偿线性二次型调节器控制算法。搭建地面试验系统,通过地面锤击试验验证得知,相比未考虑时滞问题的线性二次型调节器,时滞补偿线性二次型调节器控制算法具有较好的控制效果,能够更加稳定有效地对风洞模型振动进行控制。

In order to effectively suppress the vibration of aerocraft model in a wind tunnel test,the causes and characteristics of the vibration were analyzed by using the views of aerodynamics and mechanical dynamics,and the system of second-order model was established containing the aerocraft model,force balance and cantilever beam.Aimed at the time-delay problem in the aerocraft model vibration control,the reasons of causing time-delay and influences of it＇s influence to vibration control of wind tunnel aerocraft model were analyzed,and an identification method utilizing the information of the frequency domain signal converted from the time domain signal of the vibration and that of the actuator control was applied to obtain the value of time delay.Additionally,a time-delay compensation LQR control algorithm considering the identified delay was designed.Ground testing system was built and hammer excitation tests was conducted.The experimental results revealed that the newly proposed time-delay compensation LQR algorithm can stably and effectively damp the vibration of the wind tunnel model,better than that of no considering time-delay LQR algorithm.