Research And Design Of Oil Tank Control Circuit

Recently, oil tank liquid level automatic measurement system has been gradually replacing the traditional manual mechanical measurement method. Data processing has transformed from the mode of single point acquisition, network transmission, centralized processing to the mode of single point acquisition, single point processing, network monitoring. Through market investigation and research and demonstration, tank control instruments used in domestic are mostly imported or semi imported nowadays, there exist problems of no coordinating between instrument measurement method and statistical method of domestic, the high cost of maintenance and high difficulty of upgrading and transformation. Domestic product suffer from the problems of slow data processing speed, low measurement accuracy and poor anti-interference ability, in particular, they have a certain gap in precision and speed in signal analysis and calculation compared to the level of foreign advanced technology. Therefore, research on the development of advanced oil control node circuit has an important significance on promoting performance of automatic tank gauging systems.This thesis is focused on design of oil tank control node circuit, adopting filter method blending of wavelet threshold analysis and Hilbert Huang transformation analysis, with Simulink modular design and MATLAB simulation, the circuit is designed and simulated based on FPGA.The main contents of this thesis are as follows:(1)Analysis the basic principle and flow of the above two algorithms, deeply study the traditional Empirical mode decomposition effect processing method and the Hilbert spectrum analysis method.(2)Demonstrate the feasibility of processing ultrasonic level sensor signal blending of wavelet threshold filter and improved Hilbert Huang transform filter.(3)Compile software code combined with the improved algorithm, analyze and process the simulated waveform, verify the feasibility of method combining two algorithms.(4)Establish relevant algorithm model with the Simulink library of MATLAB, realize simulation in modular fashion.(5)Transform modular MATLAB language into VHDL file by DSPBuilder, and then compile and synthesize, complete the target device configuration, download the VHDL file to FPGA, then test and verify hardware program.The innovation of this thesis are as follows:(1) The closest similar waveform endpoint continuation method is used for analyzing and processing of ultrasonic level sensor signal.(2) Adopting two-dimensional gray Hilbert spectrum filtering in analyzing and processing tank ultrasonic level sensor signal, improve the subsequent signal processing effect and precision.(3) The filtering method combing wavelet threshold analysis and Hilbert Huang transform is applied to the analysis and processing of nonlinear and non-stationary signal of ultrasonic level sensor, realize the basic functions of liquid level control node circuit with a certain improvement in calculation accuracy, provide important support for design new model ultrasonic liquid level meter, which has research significance and application value.