Development of Joint Module with Two-speed Gear Transmission and Joint Lock Mechanism during Driving for Task Adaptable Robot

In order to achieve tasks in the real world environment, humanoid robots have motors and reduction drives optimized in relation to weight and size for providing the necessary torque and angle speed. Therefore, having torque or angle speed outside of the predicted range will usually cause the task to fail. In this research, we propose a joint module with a two-stage transmission mechanism during driving and a joint locking mechanism during non-driving so that the appropriate torque and joint speed can be attained during the task. By applying the joint module to a tricycle type robot and switching the driving state during the task execution, we were able to both reduce the motor load when lifting heavy objects at driving time and keep high rigidity of the joint at non-driving time.