Research On Design And Experiment Of Piezoelectric Bionic Wasp Stepping Linear Driver

With the development of science and technology,micro-nano drive devices have been widely used in aerospace,medical devices,military and other fields.Piezoelectric actuators,as the main research field of micro-nano precision drive devices,have very broad research prospects and important research value.At present,the research on piezoelectric actuators at home and abroad mainly includes: ultrasonic actuators,inchworm piezoelectric actuators,impact inertial piezoelectric actuators,etc.Common piezoelectric actuators usually use piezoelectric stack as the power unit of the device,which makes the driving device have some shortcomings,such as complex structure,high design cost and complex control system.In this paper,the advantages and disadvantages of some typical piezoelectric actuators are analyzed,and a piezoelectric actuator with piezoelectric oscillator as driving unit is proposed.The actuator has the characteristics of simple structure,low cost,simple control and easy miniaturization and integration.The piezoelectric oscillator is used as the dynamic unit of the whole actuator,and the variable friction support leg installed at both ends of the piezoelectric oscillator is used as the conversion unit of the vibration displacement of the piezoelectric oscillator.When the piezoelectric oscillator periodically vibrates driven by sinusoidal signal,it drives the support leg to slide on the guide rail plane.The motion of linear actuator is driven by driving force of different sizes at both ends of the actuator due to the action of support leg with variable friction coefficient.The research on driver in this paper mainly includes the following contents:1.The research status of piezoelectric actuators at home and abroad.The main research methods and some typical design principles and structures of piezoelectric actuators(ultrasonic piezoelectric actuators,inchworm piezoelectric actuators,impact inertial piezoelectric actuators)at home and abroad are described.The driving performance of some common drives and its influencing factors and shortcomings are discussed.Based on the bionic mechanism used in this paper,a piezoelectric stepping linear actuator with variable friction force is proposed.2.Introduction of Driver Design Foundation.The piezoelectric effect,basic parameters and constitutive equation of piezoelectric ceramics used in this paper are introduced.The theoretical analysis and finite element simulation of the structure design of the piezoelectric oscillator used in this paper are carried out,and the effects of the size of piezoelectric ceramics the size parameters of the vibration substrate on the equal calibration stiffness and equivalent output force of the piezoelectric oscillator are drawn respectively.The dynamic performance of the power unit(piezoelectric oscillator)of the bee driver and its influencing factors are analyzed.3.Feasibility and Structural Design Analysis of Driver.The feasibility analysis of the design scheme proposed in this paper is carried out by using finite element software.The equivalent Young's modulus of the supporting leg material(resin)used in the driver was measured.The friction coefficients of some experimental materials were calibrated.At the same time,the manufacturing method of tree bee driver is summarized4.Analysis of Motion Mechanism and Dynamics Model of Actuator.Combining with the basic structure of the actuator,the vibration form of the actuator in the course of motion is analyzed and the basic mechanism of the linear motion of the actuator is formed.Based on the basic mechanism and design structure of the actuator,the dynamic model of the actuator is built and the boundary conditions for the actuator to realize motion are proposed.Simultaneously,the second-order nonlinear equation is simplified and the steady-state displacement solution of the simplified dynamic equation is calculated.5.Experimental Study on Motion Characteristics and Main Influencing Factors of Driver.The basic method of average speed test of driver is described.At the same time,the effects of structure and design parameters on the average driving speed are explored through experiments,including longitudinal load of support leg,height of support leg,peak voltage,equivalent stiffness of piezoelectric oscillator,equivalent mass of piezoelectric oscillator,curvature radius and friction coefficient of plane contact between support leg and guide rail.Finally,some optimization schemes for driver design are proposed.