Position estimation for manipulators based on multisensor fusion

Maximizing the tracking performance of an industrial manipulators requires an accurate position estimation of the end-effector. By using the motor position from the encoder, the accuracy of end-effector position estimation is affected by the gear mechanisms employed by industrial manipulators. An accelerometer is fixed on the end-effector to get measurements that reflect the actual end-effector motion and the effect of unmodelled dynamics. In the paper a multisensor fusion method is presented to achieve good estimates of the position of the end-effector fusing the measurements from an accelerometer, a gyroscope and the encoders of joints´ motors. Since the robot dynamics and measurements are highly nonlinear and the measurement noise is non-Gaussian, the particle filter provides a solution to the sensor fusion problem. Simulation research results show an improvement in position accuracy using proposed method.