Implementation of Impedance Control for Lower-Limb Rehabilitation Robots

Rehabilitation robots are kinds of robots working together with humans to help patients in functional recovery or to assist people to move normally. Since compliance and safety during a robot-aided therapy period are important, impedance control takes both the effect and procedure in rehabilitation into consideration. Different impedance parameters (for example, inertia, damping ratio, and stiffness) are designed to ensure a robot with desired compliance and safe operation. Flexibility in the selection of those parameters ensures that impedance control makes full use of information collected in robot-aided physical therapy. This paper presents a short review of the implementation of impedance control in lower-limb rehabilitation robots. We first show the basic structure of impedance control. Then, we present an overview of the implementation of various impedance-control methods in lower-limb rehabilitation robots. Finally, we explain the limitations. challenges, and the trend in the field of rehabilitation robotics.