Homing algorithm analysis for a cable-driven 3-DOF shoulder joint

Control accuracy and consistent initial home posture is essential when we compare and analyze control algorithms. In general, in order to reduce the accumulative error of the controlling process or estimate the initial posture, the robot system need to return to its approximate home posture firstly. According to the structural characteristics of the cable-driven parallel robot, this paper describes a novel homing algorithm to a 3-DOF parallel spherical joint. Utilizing incremental encoders and limit switch to detect the home posture, the automatic homing function was realized in three steps by decoupling control to each axis of the spherical joint. Simulation was also performed to show the effectiveness of the homing algorithm.