A modular manipulator system using rotary joints toward helping the elderly and the handicapped

At present, the manipulator for the elderly and disabled has the shortcomings of long production cycle, poor versatility and cannot meet the requirements of individual differences. The modular idea is presented to the design of manipulator system. A rotary joint module is developed with the advantages of small size, light weight and large torque. It integrates mechanical structure, drive, control and communication modules and can be combined into various manipulators with different configurations on demand. A distributed control system based on industrial Ethernet and CAN bus is built using a hierarchical modular structure. It can adapt to a variety of modular manipulators characterized by low stiffness and difficulty of control. Toward assisting the elderly and disabled, a 6-DOF manipulator is assembled by utilizing 6 modular rotary joints. An impedance controller is designed based on the position force control strategies. A drawer-pulled experiment is carried out with the compliance control. Experimental results verify that the modular manipulator presented is qualified to assist the elderly and the handicapped with daily operations safely.