Decoupled Motion Control of Wearable Robot for Rejecting Human Induced Disturbances

• Published in: 2018 IEEE International Conference on Robotics and Automation (ICRA) pp. 4103 - 4110
• Main Authors: Wu, Faye Y., Asada, H. Harry
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.05.2018
• Subjects: 5G mobile communication; Australia; Automation; Conferences
• ISSN: 2577-087X
• DOI: 10.1109/ICRA.2018.8461109

When a human performs a task with the assistance of wearable extra limbs, the human movement for performing the task may inadvertently disturb the position and orientation of the robot base, making it difficult for the robot to properly carry out its objective. Therefore, unlike self-standing robots, a wearable robot must not only assist the user without interfering or prohibiting the natural human movement, but also have the capability to detect and reject disturbances caused by the wearer's motion. This paper examines such a situation, where the human attempts to twist open a bottle while a pair of robotic fingers mounted on the same arm holds the bottle in place. As the human arm rotates to twist the cap, the robot and consequently the bottle would rotate in that same direction, which makes separation of the cap from the bottle almost impossible. To compensate for the human induced disturbances, a data-driven latent space impedance control method is developed such that the robot can secure the bottle and at the same time allow natural human movement to be carried out during manipulation. Simulation and experiments have demonstrated the efficacy of the latent space impedance controller to enable single-handed object manipulation with the assistance of wearable robotic fingers.