Research On Water Depth Measuring System Based On Kalman Filter

In recent years, with the fast development of marine related business in our country, the hydrological parameters become essential factors, the depth measurement of the underwater vehicle is of great significance both for the development of naval equipment and marine exploration. As electronic technology and sensor technology develops, real-time and accurate measurement of water depth become increasingly demanding to us.Trajectory tracking and pressure sounding are two methods of measuring water depth, respectively, have their own advantages and disadvantages, while meet the independence and hidden requirements of the underwater vehicle's depth measurement.Trajectory tracking is a completely self-navigation, which according to Newton's law of inertia, use inertial sensors to measure motion acceleration of the object relative to inertial space, resulting in movement of objects drawn of the attitude and position information on the completely independent basis, However, the precision is limited by the measurement time. Kalman filter is widely used in inertial navigation technology, is a real-time optimal recursive filtering algorithm that is very easy to implement on the computer for handling multi-variable system, time-varying systems and non-stationary random process.Pressure sounding use the corresponding relation of water depth and pressure, and then calculated by measuring the pressure depth with pressure element. In the case of hydrostatic or deep water, pressure sounding has the advantages of simple calculation and easy conditions. But, when the ship near the surface of the water in stormy waves conditions, affected by the impact of storms and velocity of the water, it is hard to get the depth by using the pressure sounding.At the beginning of this text the existing various water depth measurement methods are introduced and compared both at home and abroad, and analysis focused on the impact of trajectory tracking and pressure measurement factors. Secondly the two methods of the measurement is proposed and verified through several sets of experiments. The article focuses on the Kalman Filter in sounding application, designed the filter form and parameters to meet the requirements, realize the depth of zero-point proofreading the value on trajectory tracking, and analyses the information integration between the two measuring methods. At the end of this article have introduced the software designed structure.