Research And Experimental Study For Multifunctional Depth Sensor In The Water

The multifunctional depth sensor which is composed of a diaphragm type switch and the electronic depth sensor is realized the function of linear analog signal output,passive switch andelectronic switch to meet the measurement requirements of the control system. The power supply system is disconnected when the Underwater Vehicle is just into the water, the mechanical pressure switch feel the depth along with the underwater vehicle sink in the water,the mechanical switch is contacted and the power is turned on to send the depth signal to the control system when the vehicle is up to 15m depth. In this paper the working principle and the design scheme of sensor are introduced, structural parameters, circuit principle and technology are studied and designed in detail. It is tested and analysed the results according to the relevant standards.According the characteristics of single crystal silicon the silicon piezoresistive effect principle is described through formula derivation. It is determined design parameters for the structure of silicon cup, the material of substrate, and the structure, the size, the resistance, the mixed type, the concentration of strain resistance. It is also used ANSYS finite element software to verify and design the structure parameters.Signal processing is the key to ensure the design requirements. It is researched the reason of temperature drift, analysis condition of temperature compensation, temperature compensation of bridge voltage and bridge resistance matching to determine the feasible compensation solutions. In the circuit design process, the key components performance is analyzed, the amplifying and conditioning circuit is designed in detail, and the reliability design for electronic components is completed.In the mechanical switch welded bellows design process, the working characteristics and material of diaphragm is analysed and the theory of equivalent diaphragm is researched to provide theoretical guidance for determining the diaphragm surface parameters. Through the research on the diaphragm processing technology, the mechanical pressure switch is ensured high overload resistance to achieve the correct measurement of switch signal.Finally, through the test the depth sensor has the advantages of high stability, high sensitivity, wide temperature range, impact resistance, vibration resistance ability to meet the correct measurement of the depth signal under water.