Design And Experiment Research Of Walking-Type Linear Piezoelectric Actuator

With the rapid development of science and technology,the field of MEMS has much higher requirements for displacement components,structure miniaturization and light weight.In order to meet the needs of industrial development,many new drivers have emerged at home and abroad.Among them,piezoelectric actuators have become a research hotspot because of its high precision,fast response and high reliability.In this paper,by comparing the research status and characteristics of precision drivers at home and abroad,and combining with the advantages of piezoelectric actuators,a piezoelectric bipedal linear actuator is proposed,which is designed by integrating the piezoelectric components with flexible hinges.It simplifies the assembly process and realizes a high-precision,large-stroke,fast and continuous driving.The excellent performance of the drive is proved by the optimized design of the flexible hinge and related experimental research.The specific research contents of this paper are as follows:Firstly,the research background of the driver is expounded.According to the different driving principles,the precision driving technology is described in detail.The working principle of the piezoelectric actuator is introduced,and its main features are summarized.The performance and development status of the four types of piezoelectric actuators are analyzed in detail.By comparing the relevant piezoelectric actuators at home and abroad,and combing the basic theoretical knowledge of the piezoelectric actuator with advantages,the main content and research significance of this research are proposed.Then,the basic theory of piezoelectric ceramics is introduced,and the principle characteristics of piezoelectric stack drivers are analyzed.According to the characteristics and applicable fields of piezoelectric stack drivers,the driving source of piezoelectric stacks as drivers is proposed.Secondly,a piezoelectric single-foot linear actuator is proposed.The system composition and working principle are analyzed in detail.The stator and clamping mechanism are designed and fabricated.The flexible hinges of the transmission part of the structure are classified and analyzed by basic theory.The structure of the flexible hinge was simulated by ANSYS simulation software and the modal analysis of the whole machine,which confirmed the rationality and feasibility of the design.The piezoelectric single-foot linear drive experimental platform was built to test the output performance of the driving foot to verify the feasibility of the structural design.The relationship between the tangential displacement of the driving foot and the voltage and frequency was measured.It was found that the tangential displacement can be controlled by changing the voltage.The output verifies that the driver foot can work in a wider frequency band.Experimental study on the stepping mode of the piezoelectric single-leg linear actuator shows that the moving speed of the actuator increases with the increase of the excitation frequency.In the continuous driving mode,as the excitation frequency increases,the speed of the piezoelectric single-leg linear actuator gradually increases.At a drive frequency of 2.2 k Hz,the drive reaches a maximum speed of 7.6 mm/s at no load and a maximum output force of 3.8 N.Finally,since the piezoelectric single-foot linear actuator needs to apply a large excitation frequency,it can ensure that the driver moves a large displacement in one direction.Therefore,based on the piezoelectric single-foot linear actuator,the two driving feet are placed side by side.A piezoelectric bipedal linear actuator was proposed.In this paper,the structure of the piezoelectric bipedal linear actuator is analyzed in detail.The working principle of two differential driving drives is introduced.The control program of the biped drive is written by MATLAB software.The experimental platform is built to verify the contact between the dual drive foot and the drive rod.By testing the output performance of the dual-drive foot alternate drive,the displacement response line of the drive rod is obtained,and the principle of double-foot alternating drive is verified.The load characteristics of the drive are studied experimentally.It is found that as the load increases gradually,the speed of the drive is gradually reduced,and the two are basically linear.