CN115372209A - High-sensitivity oil abrasive particle online monitoring system and monitoring method - Google Patents

Abstract

The invention discloses a high-sensitivity oil abrasive particle online monitoring system and a monitoring method, and the system comprises a sensor probe module, a driving module, a signal processing module and a signal acquisition module; the driving module generates an excitation signal to drive an excitation coil of the sensor probe; the signal processing module and the signal acquisition module are used for acquiring induction coil signals of the sensor probe, amplifying, demodulating and low-pass filtering the induction coil signals, outputting metal particle signals and finally transmitting the metal particle signals to a computer through the signal acquisition module. The invention effectively improves the acquisition precision of the online sensor and realizes the online detection of the tiny metal particles under large drift diameter and high flow rate; the method can be applied to online detection of the metal abrasive particles in an aircraft engine lubricating oil system and other mechanical equipment lubricating systems.

Description

High-sensitivity oil abrasive particle online monitoring system and monitoring method

Technical Field

The invention relates to the technical field of on-line monitoring of mechanical equipment states, in particular to a high-sensitivity oil abrasive particle on-line monitoring system and a monitoring method.

Background

Fault detection and condition monitoring of machines are important methods for maintaining the operational performance and extending the useful life of mechanical equipment. Wear is one of the important factors affecting the life and failure of mechanical equipment. During the operation of mechanical equipment, the generated metal abrasive particles can circulate together with lubricating oil, and the wear condition of the mechanical equipment can be evaluated by detecting parameters such as the size and the quantity of metal abrasive dust in the lubricating oil. The existing detection technology mainly comprises an online detection method and an offline detection method. The off-line detection method has the characteristics of long detection period, high cost and incapability of detecting equipment in real time, and has certain limitation in industrial application. The online detection method mainly comprises the following six types: optical, capacitive, resistive, ultrasonic, X-ray and inductive methods. The optical method is very poor in reliability due to the influence of bubbles in the lubricating oil. Capacitive or resistive methods can cause degradation of the oil and, over time, the detection accuracy can also decrease. The accuracy of the ultrasonic method is affected by the viscosity of the oil, flow rate and mechanical vibrations. The X-ray method has high detection precision, but the equipment is complex. The induction type metal abrasive particle detection method has the advantages of simple structure, convenience in installation, no influence of oil, capability of distinguishing ferromagnetic metal particles from non-ferromagnetic metal particles and the like, and researchers carry out a large amount of research on the method. However, in order to improve the detection accuracy of the inductive sensor, researchers generally use a microchannel sensor, which seriously affects the application of the sensor in practical engineering.

Therefore, how to improve the detection accuracy of the inductive sensor under the conditions of large pipe diameter and high flow rate is an urgent problem to be solved.

Disclosure of Invention

In order to solve the problem that an induction type sensor in the prior art is low in detection precision under the conditions of large pipe diameter and high flow rate, the invention provides a high-sensitivity oil abrasive particle online monitoring system and a monitoring method, which are used for realizing the detection of tiny metal particles under the large pipe diameter and solving the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a high-sensitivity oil abrasive particle online monitoring system comprises a sensor probe module, a driving module, a signal processing module and a signal acquisition module; the driving module consists of a signal generator and a power amplifier and is used for generating an excitation signal to drive the excitation coil; the sensor probe module consists of two groups of exciting coils and two groups of induction coils, wherein the exciting coils are reversely connected in parallel, the induction coils are connected in series in the forward direction, and a sinusoidal exciting signal is loaded onto the two exciting coils of the sensor; the signal processing module is used for amplifying, demodulating and low-pass filtering the received induction signal and outputting a metal particle signal; the signal acquisition module carries out analog-to-digital conversion on the output metal particle signal and transmits the metal particle signal to a computer.

Further, the sensor probe module comprises a coil framework, an exciting coil E1, an exciting coil E2, an induction coil S1, an induction coil S2, an exciting resonance capacitor Ce and an induction resonance capacitor Cs.

Furthermore, the excitation coil E1, the excitation coil E2, the induction coil S1 and the induction coil S2 are wound on the coil framework;

the induction coil S1 and the induction coil S2 are wound in the same direction, are respectively wound in coil grooves on two sides of the framework and are connected in series;

the excitation coil E1 and the excitation coil E2 are reversely wound, are respectively wound at the outer sides of the two induction coils S1 and S2 and are connected in parallel;

the induction resonance capacitor Cs is connected in parallel with the induction coil after being connected in series; the excitation resonant capacitor Ce is connected in parallel with the excitation coil after being connected in parallel.

Furthermore, the induction coil S1 and the induction coil S2 are wound by high-temperature-resistant enameled wires with the diameter of 0.1mm, and the number of turns is 400.

Furthermore, the excitation coil E1 and the excitation coil E2 are wound by adopting high-temperature-resistant enameled wires with the diameter of 0.2mm, and the number of turns is 300.

Furthermore, the coil framework is processed by alumina ceramics, and has good heat resistance and low heat conduction efficiency.

Furthermore, the driving module specifically comprises an STM32 singlechip excitation signal generating module and a power amplifying module, and an output port of the driving module is connected with an excitation coil E1 and an excitation coil E2 to drive the sensor.

Furthermore, the signal processing module comprises a first-stage amplification module, a second-stage amplification module, a phase-locking amplification module and a low-pass filtering module;

the primary amplification module is connected with the induction coil S1, the induction coil S2 and the induction resonance capacitor Cs and is used for carrying out primary amplification on signals acquired by the induction coil;

the secondary amplification module is used for carrying out secondary amplification on the signal output by the primary amplification module;

the phase-locked amplifying module is used for performing phase-locked amplification on the output signal of the secondary amplifying module to remove interference noise;

and the low-pass filtering module filters the carrier signal demodulated and output by the phase-locked amplifying module and outputs a low-frequency metal particle signal.

Furthermore, the signal acquisition module comprises an AD converter, and the metal particle signals output by the signal processing module are subjected to digital-to-analog conversion by the AD converter and then transmitted to a computer.

In addition, in order to realize the purpose, the invention also provides the following technical scheme: a high-sensitivity oil abrasive particle online monitoring method comprises the following steps:

firstly, generating a sine excitation signal through a driving module, loading the sine excitation signal onto two excitation coils of a sensor probe module, forming a resonant circuit by the other two induction coils and a resonant induction capacitor, and then outputting an induction signal;

then, amplifying the received induction signal through a primary amplification module and a secondary amplification module in the signal processing module; performing phase-locked amplification demodulation and low-pass filtering on the amplified output signal to output a metal particle signal;

and finally, performing analog-to-digital conversion on the output metal particle signal through a signal acquisition module, and transmitting the metal particle signal to a computer.

The beneficial effects of the invention are: the sensor for on-line monitoring of the oil abrasive particles has the characteristics of simple structure, strong anti-interference capability, high sensitivity and the like, is used in an oil abrasive particle on-line monitoring system, has a simple operation method, can effectively monitor the size and concentration of the metal abrasive particles in oil in real time, realizes the detection of tiny metal particles under large pipe diameter and high flow rate, has good real-time performance, and can be widely applied to the on-line detection of the metal abrasive particles in an aircraft engine lubricating oil system and other mechanical equipment lubricating systems.

Drawings

FIG. 1 is a schematic diagram of an on-line monitoring system according to the present invention;

FIG. 2 is a schematic diagram of an equivalent circuit of a sensor probe module;

FIG. 3 is a schematic diagram of a sensor probe module;

FIG. 4 is a schematic view of a drive module;

FIG. 5 is a schematic diagram of a signal processing module;

FIG. 6 is a graph of the voltage signal generated when 100 μm ferromagnetic metal particles pass through the sensor;

FIG. 7 is a graph of the voltage signal generated when 300 μm of a non-ferromagnetic metal particle passes through the sensor.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

Referring to fig. 1-7, two sets of excitation coils are used for reverse winding, sinusoidal excitation signals with the same frequency and amplitude are applied, the two excitation coils generate magnetic fields with the same magnitude and opposite directions and periodic variation in the internal space of the two excitation coils, the two induction coils are located inside the two excitation coils, when no metal particles pass through the sensor, the induced electromotive forces output by the two induction coils are equal in magnitude and opposite in direction, and the induced electromotive forces output after series connection are zero. Because the magnetic conductivity of the ferromagnetic metal particles is far greater than that of air and lubricating oil, when the ferromagnetic metal particles pass through, the induced voltage of one induction coil is increased, so that the voltage of the induction coil is unbalanced, and induced electromotive force is output. The magnetic permeability of the non-ferromagnetic metal particles is close to that of air and lubricating oil, but the metal particles can generate an eddy current effect under an alternating magnetic field to generate a magnetic field opposite to an excitation magnetic field, so that when the non-ferromagnetic metal particles pass through, the induced voltage of one induction coil is reduced, the voltage of the induction coil is unbalanced, and induced electromotive force opposite to that when the ferromagnetic metal particles pass through is output.

As shown in fig. 1, the present invention provides a technical solution: a high-sensitivity oil abrasive particle online monitoring system mainly comprises a sensor probe module, a driving module, a signal processing module and a signal acquisition module; the sensor probe module consists of an exciting coil E1, an exciting coil E2, an induction coil S1, an induction coil S2, an exciting resonant capacitor Ce and an induction resonant capacitor Cs, wherein the exciting coils are reversely connected in parallel, the induction coils are connected in series in the forward direction, and a sinusoidal exciting signal is loaded to the exciting coil E1, the exciting coil E2 and the exciting resonant capacitor Ce of the sensor; the driving module consists of a signal generator and a power amplifier and is used for generating an excitation signal to drive the sensor excitation coil; the signal processing module is used for amplifying, demodulating and low-pass filtering the received induction signal and outputting a metal particle signal; the signal acquisition module carries out analog-to-digital conversion on the output metal particle signal and transmits the metal particle signal to a computer.

In the above embodiment, as shown in fig. 2 and 3, the sensor probe module includes an excitation coil E1, an excitation coil E2, a resonant excitation capacitor Ce, an induction coil S1, an induction coil S2, a resonant induction capacitor Cs, and a coil skeleton. The induction coil S1 and the induction coil S2 are respectively wound in two wire slots of the coil framework, and the excitation coil E1 and the excitation coil E2 are respectively wound on the outer sides of the induction coil S1 and the induction coil S2. The exciting coil E1 and the exciting coil E2 are wound in opposite directions, the two ends of the exciting coil E1 and the two ends of the exciting coil E2 in the same direction are connected in parallel, and are connected in parallel with the resonant exciting capacitor Ce to form a resonant circuit which is connected with the driving module. One end of the induction coil S1 is connected with one end adjacent to the induction coil S2 and forms series connection, one end of the other end of the induction coil S1 is connected with one end of the resonant induction capacitor Cs, the other end of the induction coil S2 is connected with the other end of the resonant induction capacitor Cs to form a resonant circuit, and then the resonant circuit is output and connected with the signal processing module.

In a preferred embodiment, the induction coils S1 and S2 are wound with a refractory enameled wire having a diameter of 0.1mm, and the number of turns is 400.

In a preferred embodiment, the excitation coil E1 and the excitation coil E2 are wound by using a high temperature resistant enameled wire with a diameter of 0.2mm, and the number of turns is 300.

In a preferred embodiment, since the temperature of the lubricating oil in operation is generally above 100 ℃, in order to reduce the influence of the temperature of the lubricating oil on the acquisition precision of the sensor, the coil framework is processed by using alumina ceramics.

In the above embodiment, as shown in fig. 4, which is a schematic diagram of a driving module, an STM32 single chip signal generator is used to generate a 120kHz sinusoidal signal, a high pass filter is used to filter out a bias voltage, and a power amplifier is used to amplify the voltage, so that an excitation signal with an amplitude of ± 10V is output to drive an excitation coil.

In the above embodiment, in fig. 2, the resonance conditions of the capacitor Ce forming the resonance circuit with the excitation coil E1 and the excitation coil E2 and the capacitor Cs forming the resonance circuit with the induction coil S1 and the induction coil S2 are as follows:

where f is the frequency of the excitation signal, L is the inductance of the coil, and C is the resonant capacitance.

In the above embodiment, as shown in fig. 5, the signal processing module includes a first-stage amplifying module, a second-stage amplifying module, a phase-locked amplifying module, and a low-pass filtering module. The signal processing module is connected with the output end of the sensor induction coil. After the output signal of the induction coil is accessed to the signal processing module, the primary amplification module amplifies the signal by 500 times, the amplified and output signal is accessed to the secondary amplification module again, the signal is amplified by 20 times, the output signal is processed by the phase-locked amplification module, wherein a reference signal (Ref) amplified by phase locking is obtained by shifting an excitation signal, and finally the reference signal is transmitted to the signal acquisition module through low-pass filtering.

In the above embodiment, the signal acquisition module processes the signal by using the AD converter, and the signal output by the signal processing module is transmitted to the computer after being processed by the AD converter through mode conversion.

Ferromagnetic metal particles having a diameter of 100 μm and non-ferromagnetic metal particles having a diameter of 300 μm were passed through the sensor at a speed of 0.3m/s, and voltage signals output from the sensor were shown in fig. 6 and 7, respectively.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments, or equivalents may be substituted for elements thereof.

Claims (10)

1. The high-sensitivity oil abrasive particle online monitoring system is characterized by comprising a sensor probe module, a driving module, a signal processing module and a signal acquisition module; the driving module consists of a signal generator and a power amplifier and is used for generating an excitation signal to drive the excitation coil; the sensor probe module consists of two groups of exciting coils and two groups of induction coils, wherein the exciting coils are reversely connected in parallel, the induction coils are connected in series in the forward direction, and a sinusoidal exciting signal is loaded onto the two exciting coils of the sensor; the signal processing module is used for amplifying, demodulating and low-pass filtering the received induction signal and outputting a metal particle signal; the signal acquisition module carries out analog-to-digital conversion on the output metal particle signal and transmits the metal particle signal to a computer.

2. The high-sensitivity online oil abrasive particle monitoring system according to claim 1, characterized in that: the sensor probe module comprises a coil framework, an exciting coil E1, an exciting coil E2, an induction coil S1, an induction coil S2, an exciting resonance capacitor Ce and an induction resonance capacitor Cs.

3. The high-sensitivity online oil abrasive particle monitoring system according to claim 2, characterized in that: the excitation coil E1, the excitation coil E2, the induction coil S1 and the induction coil S2 are wound on the coil framework;

the induction coil S1 and the induction coil S2 are wound in the same direction, are respectively wound in coil grooves on two sides of the framework and are connected in series;

the excitation coil E1 and the excitation coil E2 are reversely wound, are respectively wound at the outer sides of the two induction coils S1 and S2 and are connected in parallel;

the induction resonance capacitor Cs is connected in parallel with the induction coil after being connected in series; and the excitation resonant capacitor Ce is connected in parallel with the excitation coil which is connected in parallel.

4. The high-sensitivity online oil abrasive particle monitoring system according to claim 3, characterized in that: the induction coil S1 and the induction coil S2 are wound by high-temperature-resistant enameled wires with the diameter of 0.1mm, and the number of turns is 400.

5. The high-sensitivity online oil abrasive particle monitoring system according to claim 2 or 3, characterized in that: the excitation coil E1 and the excitation coil E2 are wound by high-temperature-resistant enameled wires with the diameter of 0.2mm, and the number of turns is 300.

6. The high-sensitivity online monitoring system for the oil abrasive particles according to claim 2, characterized in that: the coil framework is processed by alumina ceramics, and has good heat resistance and low heat conduction efficiency.

7. The high-sensitivity online oil abrasive particle monitoring system according to claim 1, characterized in that: the driving module specifically comprises an STM32 singlechip excitation signal generating module and a power amplifying module, and an output port of the driving module is connected with an excitation coil E1 and an excitation coil E2 to drive the sensor.

8. The high-sensitivity online oil abrasive particle monitoring system according to claim 1, characterized in that: the signal processing module comprises a primary amplification module, a secondary amplification module, a phase-locked amplification module and a low-pass filtering module;

the primary amplification module is connected with the induction coil S1, the induction coil S2 and the induction resonance capacitor Cs and is used for carrying out primary amplification on signals acquired by the induction coil;

the secondary amplification module is used for carrying out secondary amplification on the signal output by the primary amplification module;

the phase-locked amplifying module is used for performing phase-locked amplification on the output signal of the secondary amplifying module to remove interference noise;

and the low-pass filtering module filters the carrier signal demodulated and output by the phase-locking amplifying module and outputs a low-frequency metal particle signal.

9. The high-sensitivity online oil abrasive particle monitoring system according to claim 1, characterized in that: the signal acquisition module comprises an AD converter, and the metal particle signals output by the signal processing module are subjected to digital-to-analog conversion by the AD converter and then transmitted to a computer.

10. The monitoring method of the high-sensitivity oil abrasive particle online monitoring system according to any one of claims 1 to 9, characterized by comprising the following steps:

firstly, generating a sine excitation signal through a driving module, loading the sine excitation signal onto two excitation coils of a sensor probe module, forming a resonant circuit by the other two induction coils and a resonant induction capacitor, and then outputting an induction signal;

then, amplifying the received induction signal through a primary amplification module and a secondary amplification module in the signal processing module; performing phase-locked amplification demodulation and low-pass filtering on the amplified output signal to output a metal particle signal;

and finally, performing analog-to-digital conversion on the output metal particle signal through a signal acquisition module, and transmitting the metal particle signal to a computer.

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