A Method for Attitude Calculation of Open TBM Based on Free Station Method and Thrust Model Integration

To address the issues of short station change distance, time-consuming procedures, and the inability of the guidance system to measure under strong vibration interference in open TBM, a new method combining a total station measurement approach based on an automatic tribrach multi-point free station method with a thrust model was proposed. By establishing a total station free station model, an attitude prediction model based on thrust stroke and other conditions, and a coordinate deviation calculation model based on coordinate transformation principles, realtime calculation of open TBM attitude data was achieved. Field test results demonstrate that the attitude data obtained by the proposed method show a deviation of ±8 mm compared to foreign system data, meeting the accuracy requirements for engineering applications. This method enables real-time measurement of open TBM attitude under strong vibration conditions and adopts a free station mode for station change, utilizing tunnel control points for measurement and station transfer. The station change efficiency is improved by 27% compared to the fixed station change mode.