Design and Control of Autonomous Underwater Vehicle using Variable Buoyancy System

The autonomous underwater vehicles are operated by power thrust to reach the desired depth. This system consumes more power or thrust and it is overcome by variable buoyancy system. In this project a feedback system is used by employing a control pressure sensor. With the help of this pressure sensor, the depth sensor is to be designed. The signal from the pressure sensor will be used to find the depth of the immersion of autonomous underwater vehicle from the top of the water surface. The signal from the pressure sensor is used to maintain the autonomous underwater vehicle at desired depth level. The sea level pressure is measured with help of pressure sensor. The output of the pressure sensor is an analog signal and is given to the ADC (analog to digital converter) port of microcontroller which takes decision on pumping sequence depending upon the input voltage (the digital value given to it)the microcontroller will control the driver unit to pump either in or out based on control signal. When the required depth level is reached the driver circuits takes some delay and automatically drives the pump out circuit to pump out the water till the preset value is reached. This sequence of pumping in and pumping out of the water will be controlled by the microcontroller for various digital input values.