A control algorithm of treadmill speed adaptation for lower extremity rehabilitation robot system

Robot-aided treadmill training is an innovative rehabilitation method for patients with locomotor dysfunctions. However, in the current rehabilitation system the treadmill speed is restricted to a constant value or adjusted by the therapist, whereas self-determined phases of accelerations and decelerations cannot be performed by the patient in an interactive and intuitive way. In order to cope with the above problems, a speed adaptive control algorithm for lower extremity rehabilitation robot system is proposed and studied. According to the characteristics that the patient´s hip joint is fixed on the robot system while walking, A pull pressure sensor is used to detect a patient´s movement trend and a nonlinear gain function is used to automatically set velocity transformation quantity in the treadmill speed controller. According to this principle, a set of force measuring device is designed and its feasibility is also verified by the physical prototype. The experimental results show that the proposed control algorithm is feasible and meets the requirement of the treadmill speed adaptation for Lower Extremity Rehabilitation Robot system.