Decoupled Scaling 4ch Bilateral Control on the Cartesian coordinate by 6-DoF Manipulator using Rotation Matrix
Koki Yamane, Sho Sakaino, Toshiaki Tsuji
TL;DR
This work tackles decoupled scaling for 4-channel bilateral control in Cartesian space under SE(3) dynamics. It introduces a rotation-matrix–based posture error using the matrix logarithm, yielding independent error dynamics across dimensions when applying scaling by $oldsymbol{\\alpha}$, $oldsymbol{\beta}$, and $oldsymbol{\gamma}$. The design combines a PD controller on pose with a proportional force term, mapped through an inverse dynamic matrix $m{H}^{-1}$, to produce the joint torques that drive the leader and follower. A MATLAB simulation with a CRANE-X7–based manipulator demonstrates that the matrix-log-based rotation error outperforms a vector-based approach in terms of rotation tracking, supporting the method's decoupling and scaling capabilities. The results suggest improved operability for teleoperation across manipulators with differing structures and pave the way for robustness and real-world validation in future work.
Abstract
Four-channel bilateral control is a method for achieving remote control with force feedback and adjustment operability by synchronizing the positions and forces of two manipulators. This is expected to significantly improve the operability of the remote control in contact-rich tasks. Among these, 4-channel bilateral control on the Cartesian coordinate system is advantageous owing to its suitability for manipulators with different structures and because it allows the dynamics in the Cartesian coordinate system to be adjusted by adjusting the control parameters, thus achieving intuitive operability for humans. This paper proposes a 4-channel bilateral control method that achieves the desired dynamics by decoupling each dimension in the Cartesian coordinate system regardless of the scaling factor.