A Non-contact Tilt Compensation Method Based on Monocular Camera/GNSS/INS

RTK with tilt compensation can achieve centimeter-level high-precision measurement. It belongs to contact measurement technology. However, in the case of signal limitation scenarios, the precision of contact measurement will be greatly reduced, or even unable to measure. This paper aims to analyze the potential and performance of a monocular camera combined with tilt compensation technology for non-contact measurement. According to the 3D model based on image reconstruction and the prior position and attitude of the GNSS receiver, the overall bundle adjustment is carried out to improve the attitude accuracy of the camera, thereby improving the accuracy of non-contact measurement. The error model of non-contact measurement is also derived in this paper, which has a very important guiding significance in practical engineering applications. The non-contact measurement method proposed in this paper does not need control points and can measure the absolute coordinates of target points in near real-time. The experimental results show that the method proposed in this paper can achieve centimeter-level high-precision measurement within the measurement range of 10m, and the mean values of horizontal, vertical, and 3D errors are 0.027 m, 0.018 m, and 0.032 m respectively.