Redundantly Actuated PRPRP Radial Mechanism in Segment Erector of Shield Machine for Synchronization Control

摘要

The shield machine is a heavy construction machine for tunnel excavation. The segment erector is an important subsystem of the shield machine. The 2DOF five-bar radial mechanism in the 6DOF erector is hard to implement the precise synchronization control. Hence, this paper proposes a redundantly actuated PRPRP radial mechanism for the segment erector. When the redundant actuator is locked or produces enough pretightening stretching force, the PRPRP mechanism can ensure the synchronization of the two driving hydraulic cylinders based on the mechanical structure. The redundant actuator can also make the two flexural torques applied at the hydraulic cylinders be the same, which avoids the overload of the single cylinder.