An master-slave control method for an upper limb rehabilitation robot system which can afford training for hemiplegic patients is introduced. The system consists of two identical motors with the master motor working in the generating state and the slave motor working in the electro motion state. Based on hemi-disabled characteristic of hemiplegic patients, the healthy limb is used to operate the master motor to generate electric energy, which in turn powers the slave motor to rotate and support impaired limb in motion imitation, thus realizing rehabilitation training. An experimental prototype with energy supplement control was developed. The appropriate amount of energy is compensated to the master- slave closed-loop circuit to compensate the inside energy loss, and further to achieve good speed tracking performance. Test experiments were conducted and the results confirm that the proposed system is capable of achieving energy recycling, motion tracking, and force sensing without a force sensor, thus has a great potential for application in rehabilitation robot systems.
