A new exoskeleton-type masterarm with force reflection :controller and integration

For robot teleoperation, a lot of research has been done to control the slave robot from a remote site using a masterarm. The concept of a distributed controller architecture for the masterarm is introduced in the paper. To reduce possible non-uniform time delay and to have higher position command update rate, the host controller with distributed satellite controllers is 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 a SPI (serial peripheral interface) protocol. For force feedback, the host controller solves the joint torque relations based on the kinematics of the masterarm and the satellite controller controls each joint´s torque. This distributed controller greatly reduces calculation and control loads and makes the electrical wiring very simple. In order to measure finger movement of the operator, the master hand is developed using infrared light. A similar slave satellite controller for this master hand is interfaced to the host controller via a SPI network. For teleoperation of the KIST humanoid robot which has two arms and two hands, the masterarm controller with one host controller and 16 satellite controllers is implemented. Force feedback with less than 2 msec update rate is achieved. This masterarm/hand is also integrated with a graphic model instead of using the slave robot. The experimental results show the performance of the distributed controller