Understanding and Evaluating Low Cost Pressure Sensor with Different Technologies for UW Vehicles

Depth measurement is a very important parameter for any underwater vehicle navigation and precise control in depth-keeping operations. The depth of the vehicle is computed from the pressure value measured by the pressure sensor manufactured using different sensing technologies. In this paper, widely used pressure sensor technologies in subsea industries are envisaged that vary with cost, sensor accuracy and resolution. The sensor selection also depends on the mission requirement and application, where the need of the pressure sensor and accurate depth measurement for low cost vehicles is very essential in the current scenario. With this objective, different denoising algorithms/ filters are applied to three different pressure sensors technologies and analyzed to identify the sensor statistics that could aid in using of low-cost pressure sensors for depth measurement that are equally performing as high accurate sensors. It is found that the computed depth data using these three algorithms is 85% accurate relative to the highly accurate sensor. The statistical parameters derived from denoising algorithms can be used as inputs to the optimal Kalman filter for estimating the depth value during pressure sensor measurement errors and outages which aids the vehicle controllability and stability during heaving operations in underwater.