US 12,092,627 B2
Signal processing system and method for inductive oil abrasive particle sensor
Zhenghua Qian, Suzhou (CN); Mingming Wang, Suzhou (CN); Peng Li, Suzhou (CN); Xianwei Wu, Suzhou (CN); Hairui Liu, Suzhou (CN); Zhi Qian, Suzhou (CN); Qi Li, Suzhou (CN); and Zelin Xu, Suzhou (CN)
Assigned to Suzhou Renzheng Zhitan Technology Co., Ltd., Suzhou (CN); and Nanjing University of Aeronautics and Astronautics, Nanjing (CN)
Filed by Suzhou Renzheng Zhitan Technology Co., Ltd., Suzhou (CN); and Nanjing University of Aeronautics and Astronautics, Nanjing (CN)
Filed on Nov. 14, 2023, as Appl. No. 18/508,648.
Claims priority of application No. 202211420906.X (CN), filed on Nov. 14, 2022.
Prior Publication US 2024/0159730 A1, May 16, 2024
Int. Cl. G01N 33/28 (2006.01); G01N 27/02 (2006.01)
CPC G01N 33/2858 (2013.01) [G01N 27/025 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A signal processing system for inductive oil abrasive particle sensor, comprising:
a sensor with two groups of induction coils;
an excitation signal generator, wherein the excitation signal generator generates an excitation signal and drives sensor excitation coils to output an induction signal containing abrasive particle information;
an analog signal processing circuit, wherein the analog signal processing circuit receives the induction signal output by the sensor, and demodulates and amplifies the induction signal;
a microcontroller unit (MCU) signal acquisition module, wherein the MCU signal acquisition module collects the processed induction signal, and transmits the induction signal to a computer;
a computer signal processing module, wherein the computer signal processing module identifies and counts the induction signal data transmitted to the computer, and displays the abrasive particle information through a monitoring panel;
the excitation signal generator includes a microcontroller unit (MCU), a digital synthesis signal generator, a first filter amplitude modulation circuit, and a power amplifier circuit;
the MCU sends a control command to the digital synthesis signal generator, and
a frequency control word in the control command is used to determine the frequency of the signal output by the digital synthesis signal generator;
the digital synthesis signal generator receives the control command, synthesizes a digital signal sequence, and outputs an analog sinusoidal signal after Analog-to-Digital (A/D) conversion and low-pass filtering;
the first filter amplitude modulation circuit processes the signal output by the digital synthesis signal generator with a high-pass filter to filter out the Direct Current offset component in the signal;
the power amplifier circuit amplifies the signal after filter amplitude modulation, and drives the sensor to excite the excitation coils to generate a magnetic field;
the analog signal processing circuit includes a Root Mean Square (RMS) conversion circuit, a second filter amplitude modulation circuit, a differential amplifier circuit and a post amplifier circuit;
the RMS conversion circuit receives the induction signals output by the two groups of induction coils of the sensor, and demodulates the two induction signals separately according to a principle of RMS detection;
the second filter amplitude modulation circuit is a high-pass filter, which filters the two induction signals that have undergone RMS detection, filters out the Direct Current offset, and leaves the induction signals containing abrasive particle information;
the differential amplifier circuit differentially amplifies two filtered induction signals, and the differentially amplified induction signals are synthesized into a sinusoidal signal waveform of one cycle;
the post amplifier circuit further filters and amplifies the differentially amplified signal to improve the signal-to-noise ratio;
the MCU signal acquisition module includes a matching and driving circuit, an A/D conversion circuit, a MCU acquisition circuit and a serial communication circuit;
the matching and driving circuit is an input voltage matching circuit of an A/D converter and a driving circuit of a successive approximation A/D converter and is used for receiving the output signal of the analog signal processing circuit, and scaling the amplitude of the signals, so that the voltage of the signals falls within the voltage range of the input signal of the A/D converter;
the A/D conversion circuit and the MCU acquisition circuit carry out A/D conversion of the signals through the A/D converter inside the MCU, and collect signals into the MCU; and
the serial communication circuit transmits the collected signal data to the computer through serial communication.