Development of a biped walking robot

This paper describes the mechanism of a biped walking robot. The biped robot consists of lower-limbs and a pelvis. Each leg has three segments such as a thigh, shank and sole that are connected through rotational joints each other. It has 12 degrees of freedom (DOF) such as two 2 DOF ankles, two 1 DOF knees and two 3 DOF hips. Its height is about 1.17 m, and its total weight is 43 kg. The movable angles of the biped robot are almost the same as a human. The actuator system of each axis consists of a motor, a timing belt, a harmonic drive gear, and two pulleys. This double speed reduction mechanism makes the biped robot have a high reduction ratio and sets the joint axis apart from the motor axis. Using the biped robot, various walking experiments are conducted and the effectiveness of the robot mechanism is confirmed.