Compliance Control of a Lower Limb Rehabilitation Robot in Mirror Therapy

Abstract

Robot-assisted rehabilitation at lower limbs have been developed extensively. Mirror therapy is applied for hemiparesis rehabilitation in this paper. The robotic system is designed which includes a sitting/lying lower limb rehabilitation robot and an attitude and heading reference system. The trajectory of the healthy limb is defined as the reference training trajectory of the robot which drives the impaired limb, then mirror image movement between patient's bilateral limbs is established. Human-robot interaction compliance control is the major concern regarding training safety. The hierarchy control frame is proposed which consists of a low-level trajectory tracking loop and a high-level admittance control loop. Experiment results validate the feasibility of the proposed scheme in providing compliance rehabilitation training.