Research On Vibration Control And Experiment Of Piezoelectric Flexible Manipulator

Flexible manipulator has the advantages of high efficiency,low energy consumption andbig payload mass ratio,etc,which has been widely used in aerospace, precisionmachining,coordinate measuring,etc.However,the elastic vibration of flexible manipulator iseasily produced in the practical application,which makes manipulator to be difficult toposition accurately,abnormal work, working efficiency and low accuracy. Therefore,theresearch of robot field is how to accurate and practical system model,and design an accuratecontroller to effectively improve the accuracy of flexible manipulator in recent years.In thispaper，terminal trajectory tracking accuracy and elastic vibration control accuracy two aspectsare employed to study the vibration control of flexible manipulator.It mainly includes thedynamics modeling,terminal trajectory tracking accuracy,elastic vibration control accuracyand experimental verification.Two-link flexible manipulator is considered as the research object,which is considered asEuler-Bernoulli.The elastic deformation is described by assumed modes method.The impactof kinetic energy and potential energy based on piezoelectric element and flexible joint areconsidered.The more accurate system dynamic equation is derived by Lagrange equation,andthe modal,angular,angular velocity and elastic deformation of flexible manipulator aresimulated by MATLAB program.The terminal state feedback equation of flexible arm is built by optimal control theory.The terminal tracking error, elastic deformation and control moment are chosen to be as theoptimum indexes. The optimal linear quadratic tracker is designed. MATLAB software iscarry to simulate to analyze terminal trajectory tracking accuracy. The simulation results showthat it can realize the high accuracy of terminal trajectory tracking by choosing the propermatrix of Q and R.The criterion of ITAE is used as the fitness function,and the particle swarm optimizationalgorithm is employed to adjust the control parameters(kp、 ki、 kd) of PID controller. Thesimulation model is builded based on MATLAB/Simulink, the simulation results show thatusing PSOalgorithm can sharply decayed the elastic vibration of flexible arm, and theelastic vibration control accuracy based on PSO control is higher than the control accuracybased on PID control.A set of vibration control experiment platform of flexible manipulator based on virtual instrument is developed. Experimental research of elastic vibration control accuracy based onpiezoelectric flexible arm is carried out. The motion of manipulator is controlled bysingle-chip computer and serial communication of LabVIEW. The vibration data is collectedthrough the data acquisition system. And the data is stored in a text file, it is convenient toread historical data. The vibration signals are guided into MATLAB to draw the vibrationwaveform. The experimental results show that with the conventional PID control algorithmand based on PSO parameters setting of PID control algorithm can both effectively inhibit theelastic vibration of flexible arm, and in accuracy, the effect of vibration suppression andstability, the latter is better than the former.