Integrated Application Research Of Shear Probe And Underwater Glider

Measurement of oceanic microstructure turbulence plays an important part in studying the changing law of ocean interior. Shear probe is the most effective tool to measure oceanic turbulence. As a new type of sensor carrying platform, underwater gliders provide a new way to measure oceanic turbulence. It will be possible to achieve long endurance and large range measurement to integrate shear probes and underwater gliders together, which have the ability of low energy cost and long endurance.This paper deals with the integration of shear probes and underwater gliders in the following way. Firstly, analysis of measurement system integration and entire design is conducted considering both the probes' requirement and underwater gliders' motion feature. Secondly, influence of the way and position of installation on turbulence measurement are analyzed,and the best way and position of installation are determined. Motion feature of underwater gliders based on turbulence measurement is analyzed. At the same time the influence of motion inputs acting on motion status parameters is evaluated. Thirdly, as the vibration of measurement platform will have negative influence on the accuracy of measurement results. So coherence function is used to analyze vibration signal. The data accuracy is improved by filtering with FRF. Finally, poor experiment and sea trial are conducted to verify the motion characteristic and the accuracy of turbulence measurement.Main contributions of the work can be concluded as follows:Integration constrain conditions of the turbulence measurement system are discussed and the integrated design of the system is developed. In order to meet the demand of shear probe working conditions, the main constraints to autonomous underwater glider in the integration of the system are discussed including gliding velocity, resonance frequency and angle of attack etc. On the other hand, to fit well with the autonomous underwater glider, the shell shape of the turbulence measurement system is designed optimally.The influences of different installation ways and positions on turbulence measurement are analyzed using computational fluid dynamics method. The better installation positions are decided, and the better installation way is determined by the index of economy and stability. The dynamic model is built based on the momentum and angular momentum theorem to express the motion features of the AUG in vertical space. Motion simulation is conducted. The motion characteristics of the AUG for the turbulence measurement are analyzed and the influence of the control inputs on the motion parameters is evaluated.Data processing method is researched to improve the accuracy of measurement. The influence of system vibration signal on the turbulent signal is analyzed using the coherence function and different effect on the turbulence signal is evaluated under different frequency band. Accurate turbulent data are obtained by filtering the vibration signal by frequency response function. And the results are proved correct through the comparison with the Nasmyth Spectrum.Turbulence measurement system are developed, and integrated with underwater glider prototypes. Poor experiment and sea trial are conducted to test the accuracy of the dynamic model and turbulence kinetic energy dissipation rate measured by underwater glider.