| The micro-positioning platform is widely used in high-tech fields such as MEMS,ultra-precision machining,biomedicine,aerospace,etc.It is of great significance to design a micro-positioning platform with large working space,high positioning accuracy,compact structure and fast response speed.Aiming at the parasitic motion generated by the micro-positioning platform,this paper designs a one-dimensional precision micro-positioning platform based on piezoelectric ceramic actuator drive.The displacement is amplified by a two-stage compliant lever amplifying mechanism,and a straight beam type flexible hinge is used as a guiding mechanism.According to the principle of virtual work,the micro-positioning platform is analyzed theoretically,and the calculation formula of the magnification and stiffness of the micro-positioning platform is derived.The finite element analysis of the micro-positioning platform is carried out by ANSYS Workbench,and the magnification and stiffness of the micro-positioning platform are simulated.The maximum stress and mode,and the experimental test system was built to test the magnification of the micro-positioning platform.The experimental and simulation results show that the maximum travel of the micro-positioning platform can reach 68.632?m,the magnification can reach 2.02,and the straightness is 1.19.Within %-1.32%,it indicates that the straightness is good,the response speed is fast,and the positioning accuracy is high.Due to the small working space of the one-dimensional platform,the application range is limited.In order to improve the micro-positioning work space,this paper designs a new two-dimensional micro-positioning platform based on the principle of flexible lever amplification.The platform consists of three rotating branches,one linear branch and four piezoelectric stacks,which can realize linear motion and rotary motion.In order to improve the comprehensive performance of the micro-positioning platform,a performance optimization design method based on response surface model is proposed.Combined with ANSYS simulation software,the correlation between the structural parameters and performance indicators of the micro-positioning platform is analyzed,and then the parameters are selected as design variables to establish the second-order response surface model of the micro-positioning platform.Genetic multi-objective optimization based onresponse surface model,and ANSYS simulation performance of the optimized micro-positioning platform.The simulation results show that the linear magnification of the optimized two-dimensional micro-positioning platform is increased by 11.91%,the rotation magnification is increased by 7.09%,the natural frequency is increased by 20.22%,the maximum stress is reduced by 10.59%,and the experimental test system is built.The magnification of the micro-positioning platform was tested.The experimental and optimization results show that the optimized value is close to the experimental value and the error is small.Explain that this optimization method is feasible.In order to reduce the influence of hysteresis nonlinear error generated by two-dimensional micro-positioning platform and improve the positioning accuracy of micro-positioning platform,this paper proposes an improved PID algorithm for feedback control of micro-positioning.The dynamic model of the micro-positioning platform is established,and the dynamic model is solved by the improved PID control algorithm.Finally,the siumlink simulation and experimental test system are used to verify.The experimental and simulation results show that the response time of the micro-positioning platform to the 5?m step response displacement is 0.28 s,and there is no overshoot.The positioning error fluctuates within the range of 0.56-0.65?m.The PID algorithm with improved algorithm can be effective.Reduce the positioning error of the micropositioning platform and have a faster response.The overall performance of the system has been significantly improved. |
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