Research On Control Of Non-resonant Elliptical Vibration Cutting Device Based On Piezoelectric Hysteresis Model

In order to reduce the influence of piezoelectric hysteresis on the motion accuracy of elliptical vibration and achieve high-precision control of elliptical vibration trajectory in elliptical vibrationassisted precision cutting,this paper aims at the working characteristics of non-resonant elliptical vibration cutting device,which directly transfers and synthesizes the output displacement of piezoelectric actuator through the structure to realize the output of elliptical vibration trajectory,and the control method of non-resonant elliptical vibration cutting device based on piezoelectric hysteresis model is studied,so the input and output hysteresis model of piezoelectric actuator is established to design the controller,and it is used to achieve accurate control of elliptical vibration track and flexible control of parameters on non-resonant elliptical vibration cutting device.The main contents and achievements of this paper are as follows:1.The piezoelectric hysteresis model of non-resonant elliptical vibration cutting device is established.According to a common structure of non-resonant elliptical vibration cutting device,the hysteresis characteristics of its axial piezoelectric stack actuator are analyzed,so the traditional PI model is improved.The unknown parameters of the traditional PI model are identified by quadratic programming algorithm,then the parameters introduced by dynamic improvement are identified by particle swarm optimization algorithm,so the model results are obtained.2.Feedforward control method and compound control method of non-resonant elliptical vibration cutting device are designed.According to the piezoelectric hysteresis model of the non-resonant elliptical vibration cutting device,a feedforward controller is designed,and the open-loop control experiment is carried out.In order to further improve the motion control accuracy of the non-resonant elliptical vibration cutting device,a compound control scheme is constructed by adding a PID feedback link on the basis of the feedforward controller.3.The morphology simulation modeling of cutting pit texture by non-resonant elliptical vibration cutting device is studied.According to the application of elliptical vibration cutting technology in micro-texture cutting,the simulation model of non-resonant elliptical vibration cutting device for cutting pit texture is established,the typical parameters of pit texture are extracted,and the influence of vibration parameters of non-resonant elliptical vibration cutting device on texture morphology is analyzed,and it provides a theoretical model reference for the application of the control method in the actual micro-texture processing of non-resonant elliptical vibration cutting device.4.The experiment of pit texture processing under compound control of non-resonant elliptical vibration cutting device is carried out.In the experiment,the device works under different vibration parameters in a compound control mode,and processes texture surfaces with different morphological parameters.By comparing with the corresponding simulation morphological parameters,it is shown that the non-resonant elliptical vibration cutting device has high micro-texture processing accuracy under the compound control.