Research On A Newly Piezoelectric Inertial Rotary Actuators Based On Magnetorheological Fluid Control

Inertial piezoelectric actuator is a kind of piezoelectric driving device which uses the inertia force and the friction force to realize the continuous motion.Because of its simple structure and easily controlled mode of motion of forming dynamics,related research is increasing in recent years.Although many domestic and foreign scholars have made a lot of important achievements in the research of Inertial Piezoelectric Actuators,the existing technology of it still have problems,such as rigid impact,high friction and wear,uneven friction,hard controlled fallback rate and low stability.In order to improve the performance of Inertial Piezoelectric Actuators,a magnetorheological fluid controlled Inertia Piezoelectric Rotary Actuator is proposed,combined with the interaction between piezoelectric inertial drive and Magneto rheological transmission technology.Specific studies are as follows:(1)The structure and movement of asymmetric clamping piezoelectric vibrator are analyzed,and the vibration modal analysis of asymmetric piezoelectric vibrator by COMSOL software.In addition,the static end displacement of the asymmetrical clamping piezoelectric vibrator is analyzed.Further,the relationship between the driving voltage,the clamping difference and the amplitude of the piezoelectric vibrator is simulated by MATLAB software.Finally,the driving torque of the piezoelectric vibrator is analyzed theoretically.According to the results of simulation and theoretical analysis,the range of clamping size difference and operating frequency of the asymmetric clamping piezoelectric vibrator are determined.(2)Based on the analysis of the rheological effect,composition and working mode of MRF,the principle of MRF selection and working mode are determined.Through the theoretical analysis of the basic performance of MRF,it is confirmed that the magnetization characteristics of MR fluid can be changed by adjusting the magnetic flux density and MR fluid concentration,and then changing the shear yield stress of MR fluids and achieving friction The torque can be adjusted steadily;the layout of the magnetic field is determined,the magnetic induction intensity of the magnetic field is simulated by COMSOL software,and the influence of magnetic flux density and MR fluid concentration on the performance of MR fluid is tested by experiments.Experiments show that the friction torque can be adjusted steadily by these two methods,which can provide good damping effect for the inertial piezoelectric actuator studied in this paper.(3)Aiming at the key problems of how to choose a reasonable structure and how to choose a reasonable control method,a friction stir plate and a magnetorheological fluid are chosen as the drive to form a shear mode.The control variables Method to change the contact area between the friction plate and the magnetorheological fluid,the magnetic particle concentration of the magnetor-heological fluid,and the solution strategy of the magnetic induction intensity.Then the theory of the working principle of the two actuators is analyzed,and the structures of the MR fluid and the mechanically controlled inertial piezoelectric rotary actuator are designed.Finally,the motion of the two types of inertial piezoelectric actuators is analyzed.(4)Experimental tests on MRF rotary actuators are carried out.The experimental results show that by controlling the concentration of MR fluid and the distance between magnets,the actuator can be controlled to roll back and improve the stability of the actuator.The experimental research on the retraction rate,linearity and repeatability ratio of the two kinds of drivers shows that under the excitation of 1Hz and 15V square wave signals,the MRF-controlled Inertial Piezoelectric Rotary Actuator has the advantages of backlash,linearity and repeatability Both are better than mechanically controlled piezoelectric actuators.