The distributed controller architecture for a master arm and its application to teleoperation with force feedback

For robot teleoperation, many researches have attempted to control the slave robot from remote site using a master arm. A new concept of the distributed controller architecture for the master arm is introduced. To reduce possible non-uniform time delay and to have higher position command update rate, the host controller with the distributed satellite controllers are developed. Each satellite controller measures the corresponding joint angle, while the host controller performs initial calibration, inverse kinematics calculation, and position commands generation. The host controller and the satellite controllers are networked via the SPI (serial peripheral interface) protocol, with maximum speed of 5Mbps. For force feedback, the host controller solves the joint torque relations based on kinematics of the master arm, and the satellite controller controls each of the joint torque. This distributed controller greatly reduces calculation and control loads and makes the electrical wiring very simple.