Research And Development Of Sea Oil Film Thickness Measurement Sensor Based On Buoy

Marine oil spill pollution has become a major source of pollution. The amount of oil spill is a key parameter to assess marine oil spill, while the oil film thickness is one of the required parameters to estimate the amount of oil spill. The accurate measurement of oil film thickness provides both the effective guidance for the disposal of oil spill and the technical foundation for the oil spreading dynamics and marine environmental science and technology, which is significant for marine environmental monitoring and remediation. Based on the analysis of oil film thickness measurement research at home and abroad, considering the characteristics of the film surface fluctuations, a method of oil film thickness measurement with vertical incidence differential laser trigonometry is proposed in this dissertation. The prototype of an oil film thickness sensor based on buoy is developed and experiments are conducted to verify its performance.The main work and innovation are as follows:1. The effect of the wave of oil film to oblique incidence laser triangulation is analysed. A method of oil film thickness measurement with vertical incidence differential laser trigonometry is proposed and the measurement formulae are theoretically derived and analysed.2. According to the requirements of measurement environment, precision and range, the buoy is designed and the software on PC is developed. The optical system is the key component, and it is carefully designed by calculation and simulation. The prototype is developed, consisting of optical system module, data processing algorithm, data communication module, power module, sampling pool, buoy shell and measuring software system module.3. The characteristics of oil spot image and standard gauge block image are analysed, with experimental system for oil film thickness measurement. Based on the analysis of various extracting spot center methods, a method of spot center extracting is presented with cross correlation and improved Gaussian fitting. The precision of algorithms are compared and analyzed. The results show that the cross correlation improved Gaussian fitting presented is of high precision.4. System integration and the debugging of buoy sensor are completed, and the test under normal condition is conducted, including the experiments of sealing, water pressure, weight adjustment, posture, waterline adjustment. Ceramic gauge block is measured for the calibration of the sensor and the calibration curve is given.5. The performance of oil film thickness measurement sensor is studied. The experiments in laboratory include measurement range experiment, measurement precision experiment and thickness measurement experiment of static oil sample. Experimental results show that the range of measurement can be 0.1mm~10mm, the relative error is less than 1%, and oil film thickness measurement is effective. In real sea environment, artificial delivery experiment in wharf and airborne delivery experiment with helicopter are carried out. The performance of the buoy sensor is tested.