Door Push-opening by Mobile Manipulator Admittance-Controlled in Cylindrical Coordinate System

- On Tuning the Origin of Cylindrical Coordinate System -

Abstract

This study realizes a door push-opening with a mobile manipulator consisting of a commercially available arm robot and a mobile robot. Especially, we assumed that the arm robot is controlled by position command every few milliseconds and that the mobile robot is controlled by a linear trajectory. Ott et al. proposed a method of implementing an impedance control in a cylindrical coordinate system on the arm robot so that the arm moves passively as the mobile robot moves forward to achieve a door push-opening. In our previous study, we implemented it by admittance control, but the excessive force was applied to the tip of the arm robot to result in overload errors. In this study, we found that such force can be reduced by properly adjusting the origin of the coordinate system. Moreover, we analyzed how the robot relaxes the excessive force and hypothesized why the position of the origin affects the excessive forces.