Intelligent Control of a Robot Manipulator for Knee Rehabilitation

There is an increasing trend in using robots for medical purposes. One specific area is the rehabilitation. There are some commercial exercise machines used for rehabilitation purposes. However, these machines have limited use because of their insufficient motion freedom. In addition, these types of machines are not actively controlled and therefore can not accommodate complicated exercises required during rehabilitation. In this study, an intelligent control structure for one degree of freedom exoskeletal robot manipulator is proposed for knee rehabilitation. It can make flexion-extension movement for knee. This manipulator is driven by servo motor and controlled by a computer using force/torque and position sensor information. The robot operates in two modes; learning and therapy. Impedance control technique is selected for the force control. The impedance control which was first proposed by Hogan (Hogan 1985) is appropriate control technique for the physiotherapy. The aim of impedance control is to specify the relationship between position and force. Proposed intelligent controller structure is used to impedance controller parameters tuning and can modify itself for reactions that come from patient.