Experimental Study On The Suppression Regression Method Of Bionic Stick-slip Piezoelectric Actuator

In recent years,with the rapid development of aerospace,micro and nano manufacturing,biomedicine and other fields,traditional drive technology has been unable to meet the needs of flexible and compact structure,small size,easy control and so on.Piezoelectric drive is a new driving technology based on inverse piezoelectric effect and step motion method,with high resolution,large output force,fast response,anti-electromagnetic interference and other advantages,very suitable for the above fields of small size,fast speed,high-precision drive technology needs,how to further improve the stroke of piezoelectric drive,output force,motion stability has become a current research focus.However,existing stick-slip drivers have an inherent problem of backsliding,which will reduce the output performance of the driver,reduce the drive efficiency and positioning accuracy,and cause bad wear to the actuator,thus reducing the service life and reliability of the piezoelectric driver.At present,the mainstream rollback suppression methods are often inseparable from the coordinated control of waveform and drive components,and multiple stators move alternately under the drive of complex sawtooth waves to achieve the purpose of rollback suppression,but this kind of rollback suppression means will lead to complex structure,large volume,complex control and other problems.Aiming at the problem that the rollback inhibition ability of stick-slip actuators is difficult to coexist with the characteristics of simple,compact structure and easy control,a systematic study was carried out in this paper.The stick-slip theory of stick-slip piezoelectric devices was analyzed,the friction models of the actuators at different motion stages were derived,and the piezoelectric cantilever beams were dynamically analyzed.The main parameters that affect the performance of cantilever beam are studied,which provides theoretical basis for structural design and friction mechanism analysis of drive friction pairs.Aiming at the problem of the structure of the anti-rollback actuator,this paper proposes a butterfly stick-slip piezoelectric actuator,carries out the structural design of the butterfly stator,conducts finite element analysis,develops a prototype and carries out test test,and uses the structure of the designed butterfly stator to develop a double butterfly multi-mode stick-slip actuator and carries out performance test.The test results show that,The designed butterfly drive has a better effect of inhibiting the rollback,and meets the demand of the simple structure of the current drive.In order to further improve the inhibition of backsliding ability of the stick slip actuator,this paper proposes a method to improve the performance of the actuator by using the bionic anisotropic surface texturing.The bionic anisotropic surface is designed by using the natural micro-nano level hierarchy of the biological surface,and the metal rigid bionic surface is prepared by means of additive manufacturing.In order to improve the friction performance of the slider/stator contact surface of the drive foot,based on the mechanical interlock phenomenon of the biological surface,a bionic surface rigid interlock stick-slip driver was designed and prepared,and a test system was built to test and analyze the output performance such as speed characteristics,load characteristics and regression rate.The biomimetic micro-structure stick-slip driver designed in this paper meets the requirements of simple structure and easy control,and further inhibits the backsliding phenomenon of the driver.In view of the problems existing in anisotropic rigid interlocking stick-slip actuators of biomimetic microstructures,this paper further studies the designed biomimetic rigid friction pairs,proposes a flexible polymer antipolydimethylsiloxane(PDMS)biomimetic friction pairs of biomimetic microstructures,analyzes the friction increasing mechanism of the biomimetic microstructures flexible film,and further develops the biomimetic microstructures flexible stick-slip piezoelectric actuators.A small stick-slip piezoelectric driving device with simple structure,easy control and complete rollback elimination was obtained.The main line of this research is to raise questions--theoretical analysis--driver structure design to suppress backsliding--driver friction subtexturing--eliminating backsliding.Through theoretical analysis of stick-slip motion,research on bending characteristics of piezoelectric cantilever beam,structural size design,research on friction mechanism of micro-structure surface,and testing of flexible friction pairs,A kind of bionic micro-structure surface flexible PDMS stick slip driver is designed and developed.The developed drive device has the advantages of easy control,simple and compact structure,excellent performance in speed and load,and complete elimination of backsliding phenomenon.The research work in this paper has broadened the technical means to inhibit the rollback of stick-slip actuators,and provided a reference for the design,analysis and application of high-performance stick-slip piezoelectric actuators.