Computing three-axis orientations of a tunnel-boring machine through surveying observation points

This research aims to develop an alternative solution to computing the three-axis orientations of a tunnel-boring machine (TBM) during microtunneling and pipe-jacking operations. Comprehensive geometric foundations are given to shed light on the computing mechanism for deriving the TBM's three rotation angles of yaw, pitch, and roll through surveying a limited quantity of observation points on the TBM. Two well-established computing algorithms in space science are elaborated, including the deterministic triaxis attitude determination (TRIAD) algorithm and the optimal quaternion method. MonteCarlo simulations are conducted to assess the accuracies on the orientations determined by the two algorithms, given (1)different levels of point surveying errors and (2)varying distances between observation points. In relation to microtunneling applications, four layout options for fixing the observation points on the TBM are designed and evaluated. To prove the concept and verify the application value of the proposed computing approach, a practical implementation case is presented, in which the computational method of quaternion was used to fix a working TBM's orientations on a microtunneling site.