三耦合柔性梁振动的视觉检测与H_(∞)控制

Visual detection and H_(∞) vibration control of three coupled flexible beams

航天器上的太阳帆板和卫星天线等为多柔性体的耦合系统。耦合多柔性体结构具有密集模态、低刚度和小阻尼等特点,易受扰动激励产生持久且幅值较大的耦合拍频振动。为了研究耦合多柔性体结构的主动振动抑制和抗扰动能力,本文针对一种三耦合柔性梁系统,采用机器视觉进行振动检测并用于反馈,通过一种非线性H_(∞)控制方法进行振动控制。建立了基于视觉检测的弹簧连接的三耦合柔性压电梁实验平台。建立了有限元模型,并且根据自由振动信号和正弦响应信号激励辨识修正了模型参数。基于H_(∞)算法给出了抗扰动指标,利用已辨识的有限元模型和所设计的非线性控制器,并且基于抗扰动指标、控制速度指标和能量消耗指标获得了H_(∞)控制器。进行了基于视觉反馈的扰动振动控制实验研究。实验结果显示:H_(∞)控制与PD控制振动抑制速度基本一致,但振动平稳时H_(∞)控制的振动幅值较小。这表明H_(∞)控制比PD控制具有更好的抗扰动能力。

Solar panels and satellite antennas on spacecraft are coupled systems with multiple flexible bodies. Multiple flexible coupling structures have the characteristics of close modes,low stiffness,and small damping;they are easily excited by disturbances to produce long-lasting and large amplitude coupled beat vibrations. To study the active vibration suppression and anti-disturbance ability of coupled multi-flexible structures,aiming at a three-coupled flexible beam(TCFB)system,the machine vision is used for vibration detection and feedback,and a nonlinear H_(∞)control method is used for vibration control. A three-coupling flexible piezoelectric beam experimental platform is established based on visual inspection and spring connection. The finite element model is established,and the parameters of the model are corrected according to the excitation identification of the free vibration and sinusoidal response signals. The anti-disturbance index is given based on the H_(∞)algorithm. By using the identified finite element model and the designed nonlinear control law,the H_(∞)controller is obtained based on the anti-disturbance,control speed,and energy consumption indices. The experimental study of disturbance vibration control based on visual feedback is carried out. The experimental results show that the vibration suppression speed of the H_(∞)control is approximately the same as that of the PD control,but the vibration amplitude of the H_(∞)control is lower when the vibration is stable. The experimental results indicate that the H_(∞)control method has better anti-disturbance ability than the PD control method.