Workspace analysis of the Π-type thrust mechanism for designing a shield tunneling machine

Abstract

To avoid interferences between the mechanical parts of the shield tunneling machine and their adjacent objects, the actual workspace of the thrust mechanism ought to be kept as a subspace of its reachable workspace. Hence, method to determine the reachable workspace of the thrust mechanism is the chief problem to be settled. This paper is focused on providing an effective method to determine the reachable workspace of the Π-type thrust mechanism. The main structure of the thrust mechanism is analyzed, and coordinate systems are built up to describe the pose and workspace of the thrust mechanism. Constraint conditions are derived and the formulation of each constraint condition is carried out to facilitate the analysis of the reachable workspace of the thrust mechanism. Meanwhile, a reachable workspace determination algorithm is introduced based on interval analysis method. Finally, applications are carried out on determining the workspace of the Φ6.46m STM to verify the validity of this method.