|Sensors||6-axis force/torque sensor|
|Actuators||DC servo motor|
|Reduction mechanism||Harmonic drive gear|
The frameworks of the robot are mainly made from aluminium alloy in order to realize a light weight, high stiffness, and a wide movable range robot. Each actuator system of the joint consists of a DC motor, a harmonic drive gear, a lug belt, and two pulleys. This double speed reduction mechanism
allows a high reduction ratio, and also a joint axis to be set apart from the motor axis.
The humanoid robot has two 7-DOF legs, a 2-DOF waist, a 2-DOF trunk, and two 7-DOF arms. The arms are designed based on a concept that the arms of the robot can hold the robot’s weight while it leans on a walk-assist machine. Because it leans on a walkassist machine, most of its weight will be distributed on both its forearms. A 6-axis force/torque sensor is mounted on each upper arm. In general, a force/torque sensor is mounted on the wrist of a robot in order to enable it to grasp, push or pull something using a hand as an end effecter.
WABIAN-2 is controlled by a PC mounted on its trunk, which consists of a PCI CPU board with a Pentium processor, PCI backplane board, three HRP Interface board, and a six-axis sensor receiver board. The HRP Interface board has a 16 channel D/As, 16 channel counters, and a 16 channel PIO.
Both ankles are equipped with a six-axis force/torque sensor for measuring the floor reaction force and the ZMP (zero moment point). Both upper arms are equipped with sensor for measuring the effect of upper body in order to be used in walking with assist machine.
Describes the design concept, the mechanisms, its control system, and experiments executed with the humanoid robot.
Describes the details of the biped foot mechanism mimicking human’s foot arch structure. Experimental results and considerations are shown. Provides conclusions and future work.
The mechanical description of WABIAN-2R is described. The principle of the pattern generation for stretched knee and heel-contact and toe-off motions are presented. The effectiveness of the development of the humanoid robot is confirmed by software simulations and walking experiments.