Sampled Adaptive Control for Multi-joint Robotic Manipulator with Force Uncertainties

This paper addresses force estimation and trajectory tracking control for robotic manipulator in the presence of uncertain external load force at end effector. One-step Guess method using one step history data sampled from actual continuous-time plant at a constant sampling interval is developed to estimate the unknown fixed or time-varying force. A discrete-time adaptive controller based on estimation of load force is designed to track desired joint trajectory. System simulation of a 6 DOF manipulator is carried out with the help of robotic toolbox in MATLAB, which demonstrates performances of the proposed scheme dealing with both fixed and variable forces, compared with traditional control method.