Task-oriented force control of parallel link robot for the assembly of segments of a shield tunnel excavation system

This paper proposes a task-oriented force control system for the assembly of segments of a shield tunnel excavation system. First, we design a generalized coordinate system referred to as a task-oriented coordinate system, so that the position and orientation of a segment can be adjusted compliantly according to the external force from existing segments with which the segment is assembled together. Then, a hybrid position/force control algorithm is designed for a parallel link robot with hydraulic actuators. The system is experimentally applied to the assembly of honey-comb shaped segments. The experimental results illustrate the validity of the proposed system.