Design And Research Of Inchworm Integrated Non-resonant Piezoelectric Actuator

With the rapid development of ultra-precision machining,aerospace engineering,bioengineering and semiconductor industries,various fields have also put forward higher requirements for precision motion.Compared with traditional electromagnetic actuators,inchworm piezoelectric actuators have the advantages of high positioning accuracy,low energy consumption,light weight and small size.This study focuses on the existing problems of the inchworm piezoelectric actuator,systematically studies the key components of the inchworm piezoelectric actuator,the flexible hinge mechanism and the displacement amplification mechanism,and proposes a new inchworm piezoelectric actuator.The main research contents include the following aspects:The working principle and actuation mode of various inchworm piezoelectric actuators are analyzed.Aiming at the problems of high machining accuracy and difficult adjustment and assembly,an integrated inchworm piezoelectric actuator based on a twostage compound displacement amplifying mechanism is proposed,which reduces the requirements for machining accuracy and reduces the overall size of the structure.The design of integrated and adjustable guide rails reduces the requirements for assembly accuracy and makes the clamping force adjustable to suit different work situations.Aiming at the research on the flexure hinge mechanism,the key element of the inchworm piezoelectric actuator,the deformation and stiffness of the flexure hinge are modeled and analyzed based on material mechanics and pseudo-rigid body model.Several key parameter variables are obtained through the formula,and the ANSYS software is used for simulation optimization.On the premise that the structure has sufficient rigidity,the maximum stress value will be minimized.On the other hand,the magnification of the two-stage compound displacement amplifying mechanism is studied,and the mathematical model of its magnification is established through kinematic analysis,and the obtained results are consistent with the simulation results.A prototype was trial-produced,and an experimental test system for the inchworm piezoelectric actuator was built.The amplitude-frequency characteristics and stability tests of the clamping mechanism and the driving mechanism were carried out respectively,which provided the necessary experimental data for the subsequent overall experiments of the motor.Experiments are carried out on the overall performance of the motor.The results show that the running speed of the motor has a linear relationship with the amplitude of the driving voltage;but the relationship with the frequency is nonlinear.With the increase of the frequency,the stability of the motor is not good.The experimental results show that the minimum resolution of the motor is 0.5μm,the maximum running speed can reach 0.08mm/s,the experimental result of the maximum load force of the motor is 2.2N,and the maximum holding force is 5.1N.Experiments show that the structure scheme of the inchworm piezoelectric actuator is feasible and achieves the expected goal.After further optimization,it can have better performance,which provides a basis for further research.