Design and validation of the simple switchable SEA module for legged system

Many researchers have been studying a walking robot that can walk in an Unknown environment. But there is a problem. When the leg is landing, the motor or torque sensor is damaged by the amount of impact generated from the uncleaned ground. In order to solve this problem, many researchers have tried to reduce the amount of impulse by placing a passive compliance element in a motor-pack. The efforts have been made to reduce the impact by creating virtual m, c, and k elements through active compliance, impedance control or admittance control. In this paper, we designed a new concept motor-pack that enters the joint of a walking robot. The main function is to make the motor-pack into a package type to protect important components from external shocks and speed up the communication speed due to the circuit intensiveness. The motor-pack consists of motor, gear, bearing, encoder and torque sensor. In addition, this paper validates the SEA module as a torque sensor.