From tunnel boring machine to tunnel boring robot: perspectives on intelligent shield machine and its smart operation

Advances in intelligent shield machines reflect an evolving trend from traditional tunnel boring machines (TBMs) to tunnel boring robots (TBRs). This shift aims to address the challenges encountered by the conventional shield machine industry arising from construction environment and manual operations. This study presents a systematic review of intelligent shield machine technology, with a particular emphasis on its smart operation. Firstly, the definition, meaning, contents, and development modes of intelligent shield machines are proposed. The development status of the intelligent shield machine and its smart operation are then presented. After analyzing the operation process of the shield machine, an autonomous operation framework considering both stand-alone and fleet levels is proposed. Challenges and recommendations are given for achieving autonomous operation. This study offers insights into the essence and developmental framework of intelligent shield machines to propel the advancement of this technology.