Series Elastic Actuators (SEAs) are attracting attention as one of the most potential actuator systems that can be utilized for robots that collaborate securely with human. SEAs generally consist of the motor part, spring and load part. The SEAs measure the deformation of the spring to calculate the externally applied force and achieve accurate force control with fidelity using various controllers.
SEAs have inherent elasticity due to the spring part, which detects force while reducing collision between humans and robots. Based on these features, it is widely used in various applications for safe human-robot collaboration. For SEAs, there have been many studies to seek for high torque control performance.