Development Of A Horizontal Self-correcting Platform For Carrying Small Seabed Seismic Sensors

The submarine seismograph has a wide range of applications in oil and gas exploration,disaster prevention and mitigation,and scientific research.It is an indispensable instrument in subsea scientific research.Among them,the submarine seismic sensor platform is an important part of the subsea seismograph.It mainly provides a safe and stable internal environment for submarine seismic sensors and some electronic devices necessary to collect seismic vibration signals,so it must have good pressure resistance and sealing performance;in addition,the platform also needs to have a self-leveling function.Ensure that the seismic sensor can work in a normal state.The submarine seismograph platform must have good coupling with the seismic sensor,and at the same time ensure good coupling with the surrounding environment,so that the surrounding vibration signals can be truly transmitted to the subsea seismic sensor.However,there are still some problems with the current submarine seismic sensor-equipped platforms,including the problems of small leveling angle range,complex structure,and poor overall structural coupling.Aiming at this situation,this paper designs a new platform structure.The main tasks are as follows:(1)A small platform of submarine seismic sensor is proposed,which has inner and outer packaging structure and self leveling function at any angle.The platform consists of internal and external packaging structure.The inner packaging structure is hemispherical,with upper cover and rod,and self leveling function;the outer packaging structure is cylindrical,the inner packaging is spherical space,and the spherical radius is the same as the spherical mating surface of the inner packaging.Therefore,no matter how inclined the outer packaging structure is,the inner platform structure of this design can ensure that the inner packaging structure is horizontal.(2)The numerical analysis of the statics of the external package structure and the dynamics of the overall structure of the platform is completed.Using ANSYS finite element simulation analysis software,strength and stability analysis was performed on the external packaging structure of the platform.The results show that the designed structure meets the requirements for use.Then,the modal analysis of the overall structure of the platform is completed,and its natural frequency is 10.342 Hz.Finally,the coupled Euler-Lagrangian(CEL)method in the ABAQUS simulation software was used to complete the fluid-solid coupling simulation analysis of the overall structure of the platform.The structural coupling was studied,and the suitable filled silicone oil viscosity in this design was 1 kcs.(3)Research the leveling and coupling performance of the platform through testing experiments.In this paper,the related performance test of the designed platform structure is completed by using the inclination sensor,seismic sensor and data acquisition card and other experimental tools.The experimental results show that the platform structure can be leveled within 30 s,the leveling angle error is within ± 1 °,and the adjustable angle range is almost unlimited;filling the 1kcs silicone oil between the package structure inside and outside the platform can Its degree of coherence in the frequency range of 5-150 Hz is generally above 0.9,indicating that the structure has good coupling at this time.