Design And Experimental Study Of Foot-type Stick-slip Piezoelectric Driven Platforms

Micro-nano positioning is a key technology in ultra-precision manufacturing,biomedical engineering,aerospace engineering and microelectronics manufacturing.Among many precision positioning devices,stick-slip piezoelectric drives have been widely studied by scholars at domestic and international level because of their high positioning accuracy,small size,fast response and large working stroke.To address the problem that the present stick-slip piezoelectric driving platform is difficult to combine both large working stroke and high loading capacity,this paper proposes the structure of integrated layout of driving mechanism and actuator,and carries out the structural design,performance test analysis and application research of foot-type piezoelectric driving platforms.The main work of the paper is as follows.First,the structural design and analysis of the single-foot piezoelectric driving platform is carried out based on the stick-slip driving principle.The theoretical and simulation analysis of the flexible mechanism of the platform is carried out by using the matrix-based compliance modeling method and finite element simulation to obtain the amplification ratio,maximum stress and operating frequency range of the flexible mechanism.The prototype of the driving platform is developed and the test system is built to test and analyze its output performance.The test results show that the singlefoot piezoelectric driving platform has the advantages of high speed,vertical loading capacity and high resolution,and can achieve stable bi-directional motion with a working stroke of more than 20 cm.In order to analyze the influence of different factors on the output performance of the platform,the dynamics model of the single-foot piezoelectric driving platform is established and its dynamics simulation analysis is carried out.Secondly,to improve the output performance of the platform,a dual-foot piezoelectric driving platform is designed with a symmetrical arrangement structure on both sides of the flexible mechanism.A test system was built to study the effects of driving parameters such as phase difference of driving signal,driving frequency and driving voltage on the output performance of the dual-foot piezoelectric driving platform.The test results show that the dual-foot piezoelectric driving platform is better than the single-foot piezoelectric driving platform in terms of motion speed and horizontal loading capacity.Further,the output performance of the dual-foot piezoelectric driving platform was compared and analyzed under two driving modes:single-foot driving and dual-foot simultaneous driving.Finally,the design and analysis of the two-degree-of-freedom piezoelectric driving platform were carried out for the practical application of precise positioning under the optical microscope,and the positioning control program was developed.The structural layout of two single-foot piezoelectric driving platforms arranged vertically at the upper and lower levels is adopted to ensure that there is no coupled motion of the platform in two degrees of freedom,and the consistency of the output performance of the two platforms is experimentally verified.Two positioning control modes,coarse and fine,are adopted,and the target point can be moved to the microscope center quickly and precisely to meet the actual use requirements.The research results of the paper provide new ideas for the design of stick-slip piezoelectric driving platform with both large working stroke,high speed and high loading capacity,and help broaden the practical applications of stick-slip piezoelectric driving platform.