Development of mechanical load adjusting device with motion measurement interface for robotic assistive rehabilitation system

The development of a rehabilitation-load adjusting device is addressed in this paper. From the viewpoint of improving the efficiency of robotic assistive rehabilitation, we designed a robot control system, in which a multi load state can be provided for a patient in a single robotic system. This system can provide the multi load state with various dynamics between the patient and a robotic rehabilitation system. The multi load state including its transition is effective and efficient in the rehabilitation. A single load state has easily been provided by the impedance control of the robot motion thus far; however, the multi load state and its transition are difficult to realize using a conventional control scheme. The proposed control scheme differs widely from a conventional impedance control scheme in that the multi load state as well as both active and passive state cannot be induced in the single robotic system. Under the proposed control scheme, the load state can be adjusted and varied with the various dynamics in the active or passive state. To confirm the effectiveness of the proposed control system, a human-robot cooperative experiment is carried out. Experimental results show that the proposed control scheme can provide the multi load state in the robotic rehabilitation.