On Humanoid Co-Robot Locomotion when Mechanically Coupled to a Hman Partner

摘要

This work focuses on the implementation of mechanically coupled tasks between a humanoid robot and a human. The latter focus comes from the push for robots to work with humans in everyday life as an overarching goal for the field. Co-robots, or robots that work alongside humans, may be guided by the humans through physical contact, such as the human grasping the robot's hand to gently guide it along a desired path. In this work the single-handed mechanically coupled task of guiding a robot through a course is implemented with four different methods of human input. These methods include: 1) using only force-torque sensors in the wrist of the robot for the control input from the human while the arm is under high-gain position control, creating a rigid coupling between the human and the robot, 2) using the force-torque sensors in the wrist of the robot for the control input while the arm is under low-gain position control with gravity compensation, creating compliant coupling between the human and the robot, 3) using the position of the end-effector of the robot for the control input while the arm is under low-gain position control with gravity compensation, and 4) using the force-torque sensors in the wrist and the position of the end-effector of the robot for the control input while the arm is under low-gain position control with gravity compensation. Tests are performed on the real-world and simulated adult-size humanoid robot DRC-Hubo++. During these tests the human and robot are walking together “hand in hand” with the human guiding the robot in a “figure eight” path. These tests show that having a compliant arm on the robot, when the human is guiding it via moving its end-effector, is beneficial over a rigid arm.