The Research Of Offshore Platform Monitoring And Measuring Devices

The complexity and uncertainty of the marine environment could easily lead to adverse effects on the structure of the offshore platform, threatening the safe of platform. In order to ensure the safe operation and optimize the structural design of the platform, the long-term field monitoring for offshore platform is needed. Due to some of their own characteristics, such as external packaging, communication mode and so on, many sensors on the market can’t meet the needs of the offshore platform monitoring. So it’s necessary to develop the specialized measuring devices according to monitoring requirements for offshore platform.In the background of the South China Sea "TiaoZhan" FPS, according to the characteristics of platform structure and climate environment, this paper studies the platform monitoring technology and measuring devices, proposes a deepwater floating platform monitoring program, and develops two measuring devices suitable for platform monitoring, Self-contained Mooring Measuring Device and Attitude and Heading Reference System (AHRS as short). The former is developed for the attitude and position of mooring chains. The internal high-precision sensors and high-resolution ADC ensure the accuracy of the instrument. Maximize the battery life by low-power design of both hardware and software. Rigorous calibration and performance tests ensure the stability and accuracy of the device. AHRS is developed for the attitude of floating body. It consists of three-axis accelerometer, gyroscope and magnetometer, takes quaternion method to calculate the attitude angles, and makes information fusion through kalman filter to compensate the error of quaternion method. The main error source, gyroscope drift, is processed by Wavelet Noise Reduction to improve calculating precision. Experiments verify the AHRS can correctly reflect the carrier attitude information. This proves that the composition scheme is feasible and the algorithm is correct.The monitoring program has been carried out on "TiaoZhan" FPS for two years, and has got a lot of data. This confirms the program is feasible and correct. The Self-contained Mooring Measuring Device has been applied in mooring monitoring for several times. The analysis results of monitoring data further validates Self-contained Mooring Measuring Device is stable and reliable, measurement data is authentic, and the instrument accuracy and resolution can meet the monitoring requirements for offshore platform mooring.