Research Of Force Compensation Control On Industrial Robot Based On Dynamics

With the development of automation,the automatic production lines are becoming much more quality and efficient.And as the major executor,the high precision and high speed control of manipulator plays important roles in industry.The industrial robots are complex coupling systems,controlling such systems only consider kinematics without referring to dynamics that explain the driving force of motion will restrict performances of manipulators a lot,some motion may even hurt the robots.Robot dynamics derives and explains the equations of forces that produce the motion on robot,and this thesis is about the dynamics of SCARA(Selective Compliance Assembly Robot Arm).To deal with the complexity of friction,add high speed compensation to the most frequently used Coulomb and Viscous friction model,the improved friction model fits better in friction experiment.Hereby uses co-simulation of Matlab and Adams to decouple the torques of friction and dynamic motion,which would keep coupling during experiments,and the simulation shows reliability about dynamic modeling and parameters identification.To deal with the problem that trajectory tracking accuracy becomes worse when robot runs in high speed,hereby proposes jerk bounded and continuous trajectory plan in joint space.Furthermore,use nine order polynomial and trigonometric function to plan the PTP motion trajectory respectively,and do experiments with cooperative algorithm.The results show that the tracking-error decreases to 7.6% and 3.5% and the position-time increases to0.024 s and 0.022 s compare to the trapezoid velocity curve.To deal with the torque uncontrollable problem when robot runs in high speed,hereby proposes acceleration iteration and optimization algorithm to optimize the acceleration of some over torque point positions in PTP(Point to Point)motions based on the prediction torque of dynamic model.Experiments show that the algorithm limits the top torque from112.2 N·m to 84.19 N·m without consuming more time,which would protect reducer from damage with the same efficiency.Since the performances of domestic servo drive and industrial fieldbus still remains to be improved,the final part of the thesis makes a short introduction about modeling and controlling of PMSM(Permanent Magnet Synchronous Motor).Base on the triple-closed-loop control of servo and dynamics of SCARA,inertia compensation and computed torque feed-forward method is proposed with expectation of reducing torque ripple and improved the stable performance of robot control systems.In this thesis,using both virtual prototype simulation and friction experiment to decoupleevery part of dynamics and validate them solely,in which way the physical meaning is clear and validation is much more reliable;derivation and application of jerk bounded and continuous algorithms shows better trajectory tracking accuracy and position-time;dynamics based algorithm ensures the torque under the reducer limitation,which would extend the life span of reducer;analysis of inertia compensation control and computed torque control based on high quality servo drive for sake of improvement in control systems.