六自由度压电隔振平台面向控制的模态分析与动力学建模

The strong coupling between the channels of the six-degree-of-freedom piezoelectric vibration isolation platform and the inherent hysteresis nonlinearity of the piezoelectric actuator pose challenges to the system dynamic modeling. In this paper, based on modal analysis technology, the control-oriented nonlinear dynamic modeling of six-degree-of-freedom piezoelectric vibration isolation platform is studied. After fully considering the hysteresis nonlinearity of the piezoelectric actuator, the Hammerstein nonlinear dynamic model of the vibration isolation platform is established by the modal coordinate transformation method, including the hysteresis nonlinearity subsystem at the input end, the decoupled modal equations and the modal positive/inverse transformation matrix. The parameters in the modal equation are identified by experimental measurement method. The static hysteresis nonlinear subsystem of the piezoelectric actuator is obtained by MPI model. The correctness of the hysteresis model is verified by inverse compensation control experiment. The modal inverse transformation matrix is obtained based on the hysteresis inverse compensation strategy. Finally, a dynamic model of the platform was established, which laid a good foundation for subsequent control.