Design And Experimental Study Of Dual-mode Diezoelectric Stick-slip Linear Actuator

With the development of science and technology in recent years,the requirements for motion positioning accuracy in the fields of aerospace,modern medical,biomedical,optical engineering,and ultra-precision machining are becoming higher and higher.Conventional driving devices such as servo motor driving,hydraulic driving,and pneumatic driving are usually used.It can only achieve the positioning accuracy of hundreds of micrometers,and it is difficult to reach the micro-nano level,which can not meet the requirements of motion positioning accuracy in the modern precision driving field.At the same time,the traditional drive unit has a large structural size and does not meet the volume requirements of many small precision systems.There is an urgent need in all fields to realize cross-scale,high-precision micro-nano motion positioning devices in small spaces to continue to advance technological development and innovation.The piezoelectric actuator with inverse piezoelectric effect has obvious advantages in terms of positioning accuracy,response speed,energy consumption,etc.,and the piezoelectric actuator has small volume,light weight,good control characteristics,high energy density,and is not subject to Magnetic field interference and other characteristics have been favored by many researchers.Piezoelectric precision drivers have a wide range of applications in various fields.Through comprehensive analysis of domestic and foreign literatures,the existing resonant piezoelectric actuators can achieve fast motion response and large output load with large stroke,but their motion accuracy is low,and accurate positioning with high motion accuracy cannot be achieved.The ruler-type piezoelectric actuator has high motion precision,but its control system is complex and cannot achieve fast motion response;the existing stick-slip inertial piezoelectric actuator has higher motion positioning accuracy,but its motion speed is higher,but Fast positioning is still not possible.Aiming at the contradiction that the existing piezoelectric actuator can not achieve the fast motion response of large stroke and the precise positioning of high motion precision at the same time,this paper proposes a dual mode piezoelectric method based on the principle of stick-slip motion by combining resonance and non-resonance.Linear drive,the specific work is as follows:Firstly,according to the advantages and disadvantages of various types of piezoelectric components,piezoelectric single-chips suitable for this design scheme are selected.The theoretical analysis,finite element simulation analysis and experimental verification of the piezoelectric single-chip selected for this design scheme are verified.Theoretical and analytical correctness;the principle of stick-slip drive is expounded,and a brief force analysis is carried out.Secondly,the proposed dual-mode piezoelectric stick-slip linear actuator is modeled,and the non-resonant working mode and resonant working mode of the driver are described in detail.The displacement output of the dual-mode piezoelectric stick-slip linear actuator is affected.The parameters were optimized by finite element parameters,and the optimal parameters of the drive were obtained.The modal simulation of the piezoelectric stick-slip linear actuator structure under this parameter was carried out to verify the feasibility of dual-mode operation.The system dynamics was established.The model lays a theoretical foundation for the subsequent experiments and analysis of the drive.Finally,a test and test system was built and tested and analyzed.The experimental results are as follows:In the non-resonant mode,when the driving voltage of the prototype is 100 V,the maximum step is about 0.569?m;when the driving voltage of the prototype is lower than 66 V,the driver cannot work stably,and the minimum step is 0.054?m.The relationship between the step size of the driver and the driving voltage is linear,linearity R~2=0.99.In the non-resonant mode(mainly f<400Hz),the step size of the driver is kept near?L=0.56?m,and the relationship between the output speed of the driver and the driving frequency is linear,The linear fit between speed v and drive frequency f is R~2=0.99;in resonant mode(around frequency 780 Hz),the maximum drive speed is 12.56 mm/s.In non-resonant mode,the relationship between the speed of the driver and the load is linear,linearity R~2=0.9,maximum load is about 1.2 N;in resonant mode,the maximum load is about 1.4 N The relationship between the speed of the drive and the load is linear,linearity R~2=0.87.The experimental results show that the proposed dual-mode piezoelectric stick-slip linear driver can achieve dual-mode driving with stable output performance.