Interface Design of Semi-autonomous Master-slave System for Excavation based on Bifurcation and Deformation of Trajectory in Nonlinear Dynamical System

Abstract

Conventional remote operation of an excavator has low work efficiency compared with direct operation. This is because it is difficult for the operator to recognize the state of the excavator and its surrounding environment. To overcome this problem, we have developed a semi-autonomous control system which consists autonomy (dynamical system with attractor) and human action (admittance control). In this paper, we propose a method of deforming the trajectory of the attractor to change the excavation start position. In the proposed method, the deformation of the trajectory is realized so as to change only the excavation start position by coordinates transformation, and the parameters in the coordinates transformation matrix are changed depending on operational force. In addition, we present a newly designed attractor for a 4-DOF excavation trajectory with bifurcation. We implement the proposed method and the attractor on the prototype of an excavation robot and verify the operation.