RONG Xin ping, ZHANG De li, WANG Xiao ping

(College of Mechanical and Electrical Engineering, Nanjing University of

Aeronautics and Astronautics, Nanjing 210016, China)

Abstract: Aiming at the problem of residual vibration suppression of multidegree of freedom robot arm with flexible joints, the coupling between joints and vibration suppression of twolink mechanical arm were studied. The vibration suppression control algorithm for flexible joints based on decoupling was proposed. First of all, the dynamic model of the whole system was established by taking advantage of the Lagrange method. Then, the interaction between joints and the vibration suppression of mechanical arm affected by the mutual coupling between the joints were analyzed. Secend, the coupling between the flexible joints of the multiple degrees of freedom manipulator was eliminated by making the use of fuzzy control method. To suppress the residual vibration of the arm due to the lack of rigidity of joints, the zero vibration shaper(ZV shaper) was introduced on the basis of decoupling to make further control of single joint after decoupling. At last, the effectiveness of the algorithm was verified through a numerical example . The results indicate that after adding the decoupling links ,mutual interferences of the two rods are decreased obviously and the coupling degree is reduced, which make each rod become approximate linear system, and each joint is optimized through the zero vibration shaper to make the vibration of mechanical arm have been effectively suppressed.

Key words: robot arm; decoupling control; fuzzy control; vibration suppression; input shape