Research On The Control Of The Piston Type Deep Sea Pressure Sensor

The ocean contains not only abundant resources, but also an important component of transportation, national defense strategy. As land resource depletion, population expansion, environmental degradation, climate change and other problems intensified, many countries have turned their attention to the ocean. And marine resources development has gradually become the strategic goal of the new world. With the development of ocean exploitation, it need put forward higher requirements on the measurement of seabed environment factors. Our group based on the National Natural Science Foundation Project is to design a deep-sea pressure sensor of a large measuring range and high precision. This paper is to study the control system of the sensor.This paper introduces the working principle of the piston type pressure sensor. According to the control system, the control system is divided into three parts, permanent magnet synchronous motor drive control, pressure signal acquisition and control system. And analysis of each component one by one, i complete the corresponding design. Using vector control method to control the permanent magnet synchronous motor, and design the current loop, speed loop and position loop based on sliding mode variable structure. After that putting on a lot of simulation and experiment. Pressure signal acquisition is mainly acquisition of tiny signal in silicon piezo resistance core body. It is based on 24 bit high accuracy ADC conversion chip AD7799 which is enough to complete the signal acquisition, and through the operational amplifier it can reduce intermediate links to reduce the influence of noise. The main control system is mainly responsible for the operation of the whole system. It can detect the pressure in real time, when the pressure reaches a certain driving the motor to balance the pressure. So that the sensitive components of silicon pressure resistance core recovery to the initial state.After completing the design of control system, Our term carry out some experiments. Through the analysis of experimental data, we confirmed the accuracy of the piston type pressure sensor can meet the design requirements.Piston type deep-sea pressure sensor designed in this paper can measure the change of micro pressure, indicating the feasibility of using the balance design of deep-sea pressure sensor. At the same time, it provides a reference for other similar sensor design.