Adaptive fuzzy sliding mode control for flexible joint manipulators

Aimed at the problems of low control accuracy and weak robustness influenced by external disturbance force, friction force, parameter variation, modeling errors and other issues in flexible joint robot control system, a new structure robust controller based on adaptive fuzzy sliding mode control was proposed. The controller consists of two parts. The nominal section of the system including the parameter relative to robot structure, deterministic disturbance and the linear part of the friction force can be controlled effectively by computed torque and feed-forward compensation of controller. The other influence of the uncertainty such as the external uncertainty disturbance, nonlinear friction force, parameter variation, modeling error and so on can be eliminated by adaptive fuzzy sliding mode control controller. Finally, experiments relative to the controller were carried out on the arm of a HIT type four degree of freedom flexible manipulator. The results showed that the controller has a good position tracking performance and a strong anti-disturbance.