Design and modelling of a novel linkage mechanism based variable stiffness actuator

A variable stiffness actuator is proposed according to the human ergonomic joint actuation mechanism and applied to an elbow rehabilitation robot. The robot employs an antagonistic compliant driving actuation to ensure rehabilitation training effectiveness and the patient´s safety even under the condition of spasm. The robot joint stiffness and position can be controlled simultaneously by using the Feldman equilibrium position control theory, experimental verification is made to verify the nonlinear spring elements in the driving mechanism.