Optimization of Location of Robotic Total Station in 3D Deformation Monitoring of Multiple Points

This paper described an optimization method of deciding the location of RTS (robotic total station) in 3D deformation monitoring of multiple points, which was widely applied in deformation/displacement monitoring in geo-engineering, such as tunnels, excavation, slopes et al. Normally the method of resection and polar coordinate was utilized in deformation monitoring by RTS, in which two datum points should be installed in immovable location and the robotic total stations could be installed in movable location. At the present stage, usually the locations were decided from human experience. This paper presented methods of evaluating the systematic accuracy-functions of the locations of the RTS and two datum points, the idea of which is from the error analysis in the geodesy field. Then the systematic accuracy could be optimized by some optimization methods. In most cases, the problem is a constrained optimization problem with 9 parameters, while in other cases, the problems could be simplified as unconstrained optimization problem, or with only 3 parameters. This method was applicable in installation of the RTS system in tunnel deformation monitoring (usually could be simplified as 2D deformation monitoring optimization with only 3 parameters), and deformation monitoring of excavation engineering.