Position Measurement of a Small-Diameter Tunneling Machine by using Gyroscope

Theoretical Analysis of the Measuring Error Based on a Dynamic Model of a Tunneling Machine

Abstract

For the purpose of a highly precise position measurement of a tunneling machine, this paper presents simple models of a tunneling machine s motion including the effect of conduits. There are two modes in the tunneling machine s movement. First, a doublestep forward movement mode that is used to hard soil, is studied. Its model is derived from the force/moment equilibrium acting on the tunneling machine, assuming elastic deformation of the ground. Next, a single-step forward movement mode that is applied to soft soil, is analyzed and its model is obtained by applying the minimum energy theory to the ground strain assuming both elastic and plastic deformations of the ground. By comparing the calculated results with experimental results, the feasibility of the proposed models is confirmed. Finally, the position measurements of the tunneling machine using a rate-gyroscope and a gyrocomps are studied. The measuring errors caused by the translation motion of the tunneling machine and by the discrete measurement are estimated by using our model. The analysis shows that the position measurement with the gyrocomps is more precise than that of using the rate-gyroscope.