Control and performance of upper- and lower-extremity SEA-based exoskeletons

In the last years, compliant actuators have become popular in the field of wearable robotics, due to their ability to enhance the safety of human-robot interfaces. One of the most well-known example of a compliant actuator is the series elastic actuator (SEA), consisting of an elastic element (e.g., a spring) in series with a stiff actuator; such actuation architecture is considered to be the simplest solution to realize compliant, compact, and light-weight actuators for wearable robots; in addition, from the control perspective, the SEA architecture allows for simple force or torque control to be implemented in addition to position control.