柔性自适应桁架及其振动最优控制实验

基于dSPACE系统和所研制的锆钛酸铅(PZT)压电作动器,建立了第一阶频率低达5Hz的三棱柱自适应桁架实验平台,通过有限元建模和实验参数修正,利用异位加速度反馈信号进行了线性二次型Gauss(LQG)最优反馈控制实验和仿真.结果表明:对比无控状态,采用最优控制只需很小控制电压,可使桁架在低阶典型频率激励下的振幅降低90%以上;而当桁架受扰动后,振动衰减时间减少超过80%;验证了实验平台配置的合理性和所研制的PZT压电作动器、控制模型的有效性;控制数值仿真与实验在加控前后振幅抑制程度相同,控制仿真与实验中振幅衰减过程的差别通过激振过程仿真与实验的对比得到了阐明.

Flexible adaptive truss testbed and its optimal control experiment for vibration

With dSPACE system and developed piezoelectric ceramic actuators, an adaptive truss shaped as a triangular prism was constructed as a testbed in t h is work. The first order natural frequency of the truss is as low as 5Hz. With t he feedback signals from accelerometers on different locations of the structure, and using linear quadratic Gaussian controller based on finite element method m odel and parameter modification through test, the experiments and simulations of vibration control were conducted. The results show that compared to the situati o n without control, the vibrating amplitude of the controlled adaptive truss unde r an exciting with fixed frequency can be damped more than 90%, and the sustaine d time of vibration after disturbance can be decreased over 80% with the proposed optimal control method. The configuration of testbed is verified to be reasonab le, and also the property of actuators and control modeling are valid. In simula tion and experiment, the vibrating amplitudes are decreased to same value, and t he difference of amplitudes decreasing processes are illuminated by the contrast of exciting processes.