Research on Tramway Kinematic Measurement Using BDS and Multisensory Fusion Technology

High-precision absolute measuring of tramway is a task of fundamental importance to plan, construct, operate and expand the tramway and its auxiliary buildings. Conventional static methods for measuring tramway coordinate, such as total stations, cannot meet the requirements of measuring efficiency. On the other hand, GNSS works as a new technology in track surveying filed to improve operational efficiency, which is unreliable to maintain tramway measuring accuracy and stability in the urban region. In this research, we proposed a multi-sensor fusion measuring approach to obtain tramway coordinate, which fully leverages the complementary advantages of BDS, INS, and odometer. This system uses the rapid kinematic mobile measuring mode and dose not depend on tramway control network. Tramway trolley borne experiments were carried out to validate the feasibility and evaluate the measuring performance of the proposed method. Results show that the measuring system can achieve an accuracy of 1.25 and 4.66 cm with 99% confidence in horizontal and vertical directions, which can meet the accuracy requirement for the tramway operation, upgrading, reconstruction, development and maintenance.