Development of a fast torque-controlled hydraulic humanoid robot that can balance compliantly

This paper reports on development of a fast torque-controlled hydraulic humanoid robot Tae-Mu. We present details on the hardware including the actuation, mechanical design, control and sensing systems. The robot has 13 active joints which are all driven by hydraulic servo cylinders with an external hydraulic power supply. The robot is installed with a three-axis active torso, which are utilized for static and dynamic balancing. The height is 141 cm, and the weight is 72.3 kg including a dummy weight stands for the arms. The lightweight design with carbon-fiber-reinforced plastic allowed the legs have the similar mass distribution to human legs. We present experimental results including basic torque control, balancing against external push, balanced squat motions and compliant balancing on a moving platform. The attached experimental video and graphs demonstrates that the fabricated robot has a high potential as a research platform for human sensory-motor control because of its compliance, high torque, speed, range of motion, safety and durability.