The lower body of humanoid biped walking robot was designed and developed by calculating each joint's torque. The lower body was composed of 2 legs like a human. And each leg has 6 joints of rotation to make full degree of freedom of human.
The hip joints of a leg are designed to have three crossing axis joints. They are hip pitching, rolling, and yawing. The knee joint is designed to endure maximum torque and speed by the result of simulation. And the ankle joints (pitching, rolling) are designed to endure low torque and speed. Because, the feet of the robot have short moment-arms.
All links of the robot are considered to have human shape and length. The length of the links is designed to have the ratio of the human who is 120 cm tall. To design the actuators of the robot, the masses of the each link are considered as the point mass where are at the end of the link.
And to drive each joint, motor driver using FET (Field Effect Transistor) was designed, which has 24V DC voltage and 13A current capacity.
