Railway Track Irregularity Measuring Based on MEMS

Railway track irregularity inspection is very important for track maintenance and assuring passenger comfort. Conventional static methods for monitoring these irregularities, such as total stations, cannot meet the track irregularity detection demand due to its low measurement efficiency. On the other hand, high-precision inertial navigation system as a new technology is include in track irregularity detection to improve operational efficiency. However, the cost of high precision inertial navigation system is very high for large-scale promotion and application. This paper proposes a novel multi-sensor fusion system for railway irregularity inspection, which is low-cost and high-efficiency. The core components of this system comprise GNSS, a cost-effective MEMS IMU and an odometer. To improve the measurement accuracy of this detection method, this paper uses the design heading angle auxiliary, 3D velocity constraint and RTS smoothing to reduce measurement errors based on the railway track strong constrains. Field test has been conducted to demonstrate the performance of the multi-sensor fusion system based on MEMS, and results show that it can measure the whole principal railway track geometric parameters within 1 mm measuring accuracy, which can meet the accuracy requirement for the railway track inspection. Our suggested technique offers a compelling, low-cost and high-efficiency solution for the railway precision surveying.