The angular velocity data of Fiber-Optic Gyro (FOG) has been analyzed to locate the singularity by the wavelet transform (WT) method. By using WT analysis method to decompose and reconstruct the signal of pavement data collecting by the FOG, the different types of pavement singularities can be extracted. The experiments are conducted on different road surfaces. The experimental results show that the locations of bumps and expansion joints have been obtained, with a relative precision of 0.5 m and an absolute precision of 2 m over 2.4 km. The characteristic of the pavement roughness can also be identified.
The continuous three-dimensional curved track measurement system (CTMS) based on vehicular strapdown inertial navigation system (SINS) and four odometers is firstly presented and validated in order to achieve rapidly the long span curve measurement for bridge health monitoring. The line-shape measurement is conducted on a viaduct. Experimental results show that the Z-axis and Y-axis error in comparison with total station for 180 m curved viaduct are 6.39 cm and 37.16 cm respectively. The system which will be further improved has potential applications for bridge health monitoring in the future.
（1National Engineering Laboratory for Fiber Optic Sensing Technology, 2Key Laboratory of Fiber Optic Sensing Technology and Information Processing, Wuhan University of Technology, Wuhan, 430070, China） Abstract: In view of the high voltage, strong magnetic field environment of high voltage switchgear, the isolation contact temperature measurement scheme of optical fiber based on wireless sensor technology realizes the contact temperature monitoring of high-voltage switchgear. In this scheme, good thermal conductivity and insulation ceramic materials are selected as outer jacket material sensing probe, and the program has a good solution to the problem of high and low voltage isolation; Combination of optical fiber composite insulator for wireless sensing, solves the problem of high voltage insulation, but also to avoid the "creeping" phenomenon due to dust. The package structure and reasonable installation solve the cross sensitivity of strain. Application shows that the precision of temperature measurement of the system can reach ± 0.5 ℃ and can work in a variety of harsh environment. It can improve the reliability of the operation of electrical equipment significantly and has considerable practical value for the normal operation of the whole power system.