Study on Measuring Error Caused by Movement of Benchmark for Auto Total Station in Health Monitoring

摘要

Nowadays,auto total station is gradually applied in real-time health monitoring for large structures,due to its character of reliability and high precision etc.While in long-term deformation monitoring without guard,auto total station has to be fixed on unstable area,when large complicate structures or buildings around block light beam.In this instance,the benchmark which total station fixed on(called instrument base)may be moved with deformation of structure.This movement of benchmark will introduce measuring error.To address this problem,a mathematics model of error caused by movement of bench mark in threedimension is set up based on measuring principle of total station.Measuring error caused by movement of benchmark is analyzed.A compensation method to correct coordinate of measuring points is proposed after analyzing transfer principle of this error and establishing relationship between coordinate change of benchmark and the error.Furthermore,a corresponding survey method to improve measuring precision is introduced.At last,an experiment with a Leica TCA 1800 total station is carried out.The experiment results show that mathematics model of error is correct and the compensation method to improve precision is feasible,coordinates error of measuring points is less in 4mm.