A multi-parameter on-line monitoring device and method for abrasive particles

Abstract

A kind of abrasive particle multi-parameter on-line monitoring device and method, belong to mechanical equipment wear monitoring technical field, including inductance monitoring module, imaging monitoring module, paramagnetic magnetophoresis separation device, collection cleaning device, system processor.Inductance monitoring module detects the magnetic field disturbance generated when abrasive particle passes, obtains the size, number and ferromagnetic property of abrasive particle, is transmitted to system processor;Imaging monitoring module is triggered according to the inductance pulse signal of inductance monitoring module by system processor, and the shape and size information of abrasive particle are obtained by imaging abrasive particle;Paramagnetic magnetophoresis separation device is used to separate paramagnetic and diamagnetic abrasive particle, and is connected with collection cleaning device.The present application can obtain the information of multiple abrasive particles simultaneously, has the advantages of anti-bubble interference, high response sensitivity, can distinguish paramagnetic and diamagnetic, can multiple information authentication, etc.;The specific occurrence site of mechanical fault and its severity, wear mechanism can be analyzed and confirmed, to ensure that equipment is safe and efficient operation.

Description

Technical Field

[0001] This invention belongs to the field of mechanical equipment wear monitoring technology, and relates to an online multi-parameter monitoring device and method for abrasive particles. In particular, it relates to an online multi-parameter monitoring device and method for abrasive particles based on multi-level inductive collaborative imaging and magnetophoretic separation. The device and method achieve abrasive particle size and morphology analysis through an inductive pulse-triggered imaging module, and combine a collaborative detection technology that distinguishes paramagnetic and magnetic particles with the magnetophoretic effect. It also provides an online monitoring method to estimate the volume of ferromagnetic particles and the surface area of ​​non-ferromagnetic particles in scenarios with multiple particles occurring simultaneously, and is designed to resist bubble interference. Background Technology

[0002] As a core component of an engine, the lubrication system plays an irreplaceable role in ensuring reliable operation. This system effectively slows down the performance degradation of mechanical components by establishing a stable lubricating oil film. When the rotating parts in an engine have accumulated a certain amount of service time, abnormal friction at the contact surfaces can cause microscopic peeling of the material surface, leading to the formation of wear particles with specific characteristics.

[0003] These micron-sized particles generated by friction circulate with the lubricating oil in a closed system, and their physical properties contain rich information about the equipment's condition. By analyzing these characteristic parameters, the real-time operating status of key moving parts and their material damage modes can be accurately determined. Therefore, developing wear monitoring technology with early fault warning capabilities has become an important research direction in the health management of modern machinery. The application of this technology can not only effectively prevent further deterioration of equipment performance but also provide data support for formulating precise maintenance strategies, ultimately achieving efficient management and control throughout the entire lifecycle of machinery.

[0004] Currently, online lubricating oil wear monitoring technology is developing rapidly, and inductive sensors are highly favored due to their high sensitivity and material discrimination capabilities. Inner Mongolia Agricultural University has designed and developed an online synchronous detection sensor for lubricating oil wear particles and moisture based on the principles of electromagnetic induction and image distortion (Chinese invention patent CN118624709A). The inductive detection unit uses an induction coil to sense the difference in phase and peak value of wear particles under an alternating magnetic field to determine the type and size of the wear particles. However, it cannot distinguish between paramagnetic and diamagnetic non-ferromagnetic wear particles, and the wear particle morphology, as the sole source of information on the wear mechanism, is also unavailable. Furthermore, it cannot handle situations where multiple wear particles pass by simultaneously.

[0005] Undoubtedly, the amount of information contained in images is unparalleled by other methods. Almost all abrasive particle features, including size, concentration, and morphology, can be extracted from abrasive particle images. Zhejiang University proposed a method and device for detecting oil abrasive particles based on microscopic holography and magnetic field control (Chinese Invention Patent CN117054296A), which can simultaneously measure multiple parameters such as particle size, concentration, and morphology of lubricating oil wear particles online. However, this method can only simply distinguish between ferromagnetic and non-ferromagnetic abrasive particles through the magnetic field, and cannot distinguish between paramagnetic and diamagnetic abrasive particles, resulting in significant limitations in identifying wear sources.

[0006] In summary, both inductive detection technology and optical image detection methods offer high precision. By combining electromagnetic principles with optical imaging principles, an imaging module is triggered by an inductive pulse to generate a time-stamped stream of particle events. This stream is then combined with gradient magnetic fields and magnetophoresis to distinguish between paramagnetic and diamagnetic particles, simultaneously acquiring information such as the material (wear source), shape (wear mechanism), and size (wear severity) of the abrasive particles. Furthermore, due to the insensitivity of the inductive coil to air bubbles, the triggering mechanism effectively eliminates bubble interference. This invention addresses the real-time monitoring needs of multiple abrasive particles passing through lubricating oil pipelines. It designs an integrated online multi-parameter monitoring device for lubricating oil abrasive particles, ensuring that it can determine the wear status of equipment online and collect and periodically clean abrasive particles in the pipeline, guaranteeing the safe and efficient operation of the mechanical device. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention proposes a multi-parameter online monitoring device and method for abrasive particles. It generates a timestamped particle event stream by triggering an imaging monitoring module with inductive pulses, and then distinguishes between paramagnetic and diamagnetic abrasive particles using magnetophoresis. This allows for the simultaneous acquisition of information such as abrasive particle material (wear source), shape (wear mechanism), and size (wear severity). Furthermore, this invention solves the problem of traditional optical sensors being unable to eliminate bubble interference, effectively handling scenarios with multiple particles occurring simultaneously. Additionally, the detachable collection tank design enables the cleaning of abrasive particles.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A multi-parameter online monitoring device for abrasive particles is disclosed, specifically a multi-level inductive collaborative imaging and magnetophoretic separation device. The device includes an inductive monitoring module, an imaging monitoring module, a para-diamagnetic magnetophoretic separation device 6, a collection and cleaning device, and a system processor 7. The inductive monitoring module detects magnetic field disturbances generated when abrasive particles pass through, generates inductive pulse signals to obtain the size, number, and ferromagnetic properties of the abrasive particles, and transmits the signals to the system processor 7 via wires. The imaging monitoring module, triggered by the inductive pulse signals from the inductive monitoring module, images the abrasive particles to obtain their shape and size information, and then transmits the image data back to the system processor 7 via wires. The para-diamagnetic magnetophoretic separation device 6 uses a gradient magnetic field to separate paramagnetic and diamagnetic abrasive particles. The separation process is monitored by the second-level imaging monitoring module 5 of the inductive monitoring module and is connected to the collection and cleaning device via a flow channel. The collection and cleaning device collects and cleans the separated abrasive particles and is detachably connected to a pipe outlet. The system processor 7 is used to receive and process signals from the inductance monitoring module, including filtering circuits, amplification circuits, A / D conversion, and an FPGA; it controls and triggers the imaging monitoring module, processes image data, calculates wear particle parameters, and coordinates communication and data flow throughout the monitoring process. Specifically:

[0010] The inductive monitoring module, surrounding the outside of the lubricating oil pipe, includes a first-stage inductive monitoring module 1 and a second-stage inductive monitoring module 4 with identical structures. It is used to detect magnetic field disturbances generated when abrasive particles pass through, generating inductive pulse signals to obtain the size, number, and ferromagnetic properties of the abrasive particles. Both the first-stage and second-stage inductive monitoring modules 1 and 4 consist of three stacked planar coils, aligned at their centers, sharing a common hollow circular hole through which the lubricating oil pipe passes. The three planar coils include two excitation coils 8 and one induction coil 9. The induction coil 9 is located in the middle, with the two excitation coils 8 symmetrically arranged on either side. The induction coil 9 transmits the signal to the system processor 7 via a wire. This design, with its integrated planar coils, achieves a highly dense and precisely symmetrical configuration of the excitation coils, which improves the sensor's response sensitivity.

[0011] The imaging monitoring module is located outside the lubricating oil pipeline and includes a first-stage imaging monitoring module 2 and a second-stage imaging monitoring module 5 with identical structures. Triggered by the system processor 7 based on the inductance pulse signal from the inductance monitoring module, it images the abrasive particles, acquiring their shape and size information, and transmits the image data to the system processor 7 via a wire. Both the first-stage imaging monitoring module 2 and the second-stage imaging monitoring module 5 are composed of a laser 10, a lens 11, and a CMOS sensor 12 arranged sequentially from top to bottom; the laser 10, lens 11, and CMOS sensor 12 are on the same central axis, which is perpendicular to the axis of the lubricating oil pipeline. The laser 10 is located above the lubricating oil pipe and is connected to the system processor 7 via a wire. It is triggered by an inductor pulse signal generated by the inductor monitoring module and is used to provide a uniform light source to illuminate the observation window on the lubricating oil pipe. The lens 11 is located below the lubricating oil pipe and is used to collect and converge light carrying the contour and morphology information of the abrasive grains onto the photosensitive surface of the CMOS 12. The CMOS 12 is located below the lens 11 and also below the lubricating oil pipe. It is used to convert the collected photoelectric signals into digital images of the abrasive grains and then transmit them to the system processor 7.

[0012] The antimagnetic magnetophoresis separation device 6 is located in the lubricating oil pipeline after the second-stage inductance monitoring module 4. It is part of the pipeline flow, and abrasive particles are separated after flowing through the antimagnetic magnetophoresis separation device 6 with the lubricating oil. It includes a magnetophoresis channel 14, magnetic poles 15, ferromagnetic wires 16, and claw-shaped channel 17. The magnetophoresis channel 14 serves as the main pipeline of the antimagnetic magnetophoresis separation device 6 and is directly coaxially connected to the lubricating oil pipelines at both ends to form a continuous flow path. The magnetic poles 15 are symmetrically arranged on both sides of the magnetophoresis channel 14, forming a uniform external magnetic field. Located on the horizontal periphery of the pipe, their magnetic field penetrates the pipe wall, creating an initial uniform magnetic field inside the device. The ferromagnetic wires 16 are arranged along the oil flow direction at the center of the magnetophoresis channel 14, penetrating the entire separation zone. They disturb the uniform magnetic field generated by the magnetic poles 15, creating a gradient magnetic field with uneven strength around the ferromagnetic wires 16. The claw-shaped channel 17 is located at the downstream outlet of the magnetophoresis channel 14, extending from and fixedly connected to it. This channel consists of a central outlet and two side outlets, forming a "claw-shaped" branch structure. Its special angle design ensures precise separation of paramagnetic and diamagnetic abrasive particles under the action of magnetophoresis force and fluid inertial force.

[0013] The collection and cleaning device includes a ferromagnetic abrasive particle collection and cleaning device 3, a paramagnetic abrasive particle collection tank 18, and a diamagnetic abrasive particle collection tank 19. The ferromagnetic abrasive particle collection and cleaning device 3 is installed between the first-stage imaging monitoring module 2 and the second-stage inductive monitoring module 4, and is used to adsorb and clean ferromagnetic abrasive particles. The paramagnetic abrasive particle collection tank 18 is installed at the rear end of the central outlet of the paramagnetic-diamagnetic magnetophoretic separation device 6, and its inlet is equipped with a filter screen 20 to trap paramagnetic abrasive particles while allowing lubricating oil to pass through. The diamagnetic abrasive particle collection tank 19 is installed at the rear end of the side outlet of the paramagnetic-diamagnetic magnetophoretic separation device 6, and its inlet is also equipped with a filter screen 20 to trap diamagnetic abrasive particles. Furthermore, the device can be disassembled periodically to achieve the purpose of cleaning abrasive particles.

[0014] The system processor 7 is used for signal processing and abrasive event detection, collaborative trigger control, multi-source data fusion, and parameter calculation. It includes a filtering circuit, an amplification circuit, an analog-to-digital converter (A / D converter), and a field-programmable gate array (FPGA). The filtering and amplification circuits are used to denoise and amplify the inductor pulse signal from the inductor monitoring module. The A / D converter converts the inductor pulse signal into a digital signal for subsequent digital processing. The core computing and control components of the system processor 7 are responsible for implementing high-speed digital logic, specifically for threshold comparison, trigger signal generation, precise delay control, and timestamp management.

[0015] Furthermore, in the inductance monitoring module, two excitation coils 8 are wound in opposite directions and connected in series by leads. Excitation signals are applied to both ends of the lead interface. The magnetic fields generated by the excitation coils 8 cancel each other out at the middle induction coil 9, so that the induction coil 9 is in a zero magnetic field, which increases the rate of change of magnetic flux when the abrasive particles pass through the inductance monitoring module.

[0016] Furthermore, the external magnetic field of the paramagnetic-diamagnetic separation device 6 is applied by the magnetic poles 15 placed horizontally in the lubricating oil pipe. The presence of ferromagnetic lines 16 makes the originally uniform external magnetic field non-uniform, and paramagnetic abrasive particles are attracted to the vicinity of ferromagnetic lines 16, while diamagnetic abrasive particles are pushed towards the side wall; paramagnetic abrasive particles flow out through the central outlet, and diamagnetic abrasive particles flow out through the side outlet.

[0017] Furthermore, the imaging range of the second-stage imaging monitoring module 5 covers the rear half of the magnetophoresis channel 14 and the front half of the three outlets of the antimagnetic magnetophoresis separation device 6, so as to achieve a one-to-one correspondence between abrasive particle images, antimagnetism, and inductive pulse signals.

[0018] A method for online multi-parameter monitoring of abrasive particles, based on the aforementioned online multi-parameter monitoring device, is used for online multi-parameter monitoring of abrasive particles. The abrasive monitoring device acquires abrasive particle passing signals and generates pulses through a first-stage inductive monitoring module 1. These pulses trigger a first-stage imaging monitoring module 2 to simultaneously acquire information on the size (wear degree) and shape (wear mechanism) of the abrasive particles. The volume is estimated by summing the absolute values ​​of the pulse amplitudes of the first-stage inductive monitoring module 1 and the second-stage inductive monitoring module 4, and this is verified with the imaging information. The second-stage inductive monitoring module 4 acquires the "negative-positive" pulses generated by remaining non-ferromagnetic abrasive particles, and analyzes the pulse amplitude to estimate their surface area. The non-uniform magnetic field disturbed by ferromagnetic wires 16 attracts paramagnetic particles to the vicinity of ferromagnetic wires 16, which are then discharged through the central outlet. Simultaneously, diamagnetic particles are pushed to the sidewall and discharged through the side outlet, thus completing the material differentiation and sorting of ferromagnetic, paramagnetic, and diamagnetic abrasive particles. Throughout the process, a triggering mechanism eliminates bubble interference, and a removable collection tank enables abrasive particle collection and cleaning. Specifically, the method includes the following steps:

[0019] The first step involves the abrasive particles passing through the first-stage inductive monitoring module 1, causing a magnetic field disturbance and triggering an inductive pulse signal in the induction coil 9. Utilizing the opposing effects of ferromagnetic and non-ferromagnetic particles on the original magnetic field, the output signals are out of phase, allowing for the differentiation of abrasive particle types in the lubricating oil. The output signal is then sent to the system processor 7 via the induction coil 9 lead interface. It passes through a filtering circuit and an amplification circuit, and finally is processed by an A / D converter input to the FPGA, achieving real-time, online monitoring of lubricating oil abrasive particles. The same process occurs when multiple abrasive particles pass through the first-stage inductive monitoring module 1 simultaneously; however, this method cannot differentiate between ferromagnetic and non-ferromagnetic particles, only serving a triggering function. Specifically:

[0020] Step 1.1: The two excitation coils 8 within the first-stage inductance monitoring module 1 are connected in reverse series. Under the same excitation signal, they generate two magnetic fields of equal magnitude and opposite direction in the region where the induction coil 9 is located, causing them to cancel each other out and thus establishing a background environment close to zero magnetic field. When abrasive particles pass through the first-stage inductance monitoring module 1, this equilibrium state will be significantly disturbed: ferromagnetic abrasive particles will enhance the original magnetic field, increasing the magnetic flux of the induction coil 9; while non-ferromagnetic abrasive particles will weaken the original magnetic field due to the eddy current effect, reducing the magnetic flux. By detecting the inductance pulse signal generated by the induction coil 9 through the system processor 7, the size, number, and ferromagnetic properties of the metal abrasive particles in the oil can be obtained.

[0021] Step 1.2, the inductance pulse signal and inductance change caused by the passage of a single abrasive grain, specifically:

[0022] The induced electromotive force generated by the change in magnetic flux in the induction coil circuit 9 for:

[0023] (1)

[0024] Where t represents time; Let be the flux linkage of induction coil 9, expressed as:

[0025] (2)

[0026] in, The inductance of induction coil 9; This is the induced current in induction coil 9;

[0027] The induced electromotive force can then be further expressed as:

[0028] (3)

[0029] The inductance monitoring module can be equivalent to a multi-layered, tightly wound solenoid with a length equal to the diameter of the conductor. When a relative permeability is... The change in system inductance caused by spherical abrasive grains passing through the equivalent solenoid. It can be modeled as:

[0030] (4)

[0031] in, The diameter of the wound wire; This represents the number of turns in the coil. The length of the equivalent solenoid; Permeability of free space; The radius of the spherical abrasive grain; denoted as ρ, represents the relative permeability of the spherical abrasive grains.

[0032] Step 1.3, signal superposition in multi-abrasive concurrent scenarios, specifically:

[0033] When multiple abrasive particles pass through the first-stage inductive monitoring module 1 simultaneously, each abrasive particle independently disturbs the magnetic field, and the total induced electromotive force output by the induction coil 9... The linear superposition of the induced electromotive forces contributed by all individual abrasive grains:

[0034] (5)

[0035] in, The total induced electromotive force output by induction coil 9; The induced electromotive force caused by the kth abrasive grain; This represents the change in magnetic flux linkage generated on induction coil 9 caused by the kth abrasive grain; This represents the total number of abrasive particles passing through simultaneously.

[0036] Correspondingly, the change in total magnetic flux linkage of induction coil 9 Also, the algebraic sum contributed by all individual abrasive particles:

[0037] (6)

[0038] The second step involves the inductance pulse signal generated when the abrasive grains pass through the first-stage inductance monitoring module 1. This signal is controlled by the FPGA module in the system processor 7 to trigger the first-stage imaging monitoring module 2 to capture images of the shape and size of the abrasive grains. These two features correspond to the wear mechanism and the severity of wear, respectively, effectively avoiding information redundancy and eliminating bubble interference. When multiple abrasive grains pass through simultaneously, the first-stage imaging monitoring module 2 can also acquire their shape and size information. Specifically:

[0039] Step 2.1: When the abrasive particles pass through the first-stage inductance monitoring module 1, the inductance pulse signal generated by its induction coil 9 is processed by the system processor 7 (including filtering, amplification, and A / D conversion) to generate a digital pulse signal. The FPGA module of the system processor 7 sets the voltage threshold. When the absolute value of the processed inductor pulse signal amplitude satisfies When this occurs, it is determined to be a valid abrasive event. This is based on the lubricating oil flow rate. The distance between the imaging areas of the first-level inductance monitoring module 1 and the first-level imaging monitoring module 2 Calculate trigger delay :

[0040] (7)

[0041] in, This indicates the flow rate of the lubricating oil.

[0042] When the FPGA module within the system processor 7 detects a pulse delay... The output TTL level signal drives the laser 10 to ensure that the laser is turned on synchronously when the abrasive particles arrive at the imaging area, and to meet the abrasive particle motion blur suppression condition:

[0043] (8)

[0044] in, For abrasive grain feature size, For lubricating oil flow rate, The exposure time for laser 10 to emit laser light.

[0045] Step 2.2: When the abrasive particles pass through the first-stage imaging monitoring module 2, images of the abrasive particles are acquired. Specifically:

[0046] The short-duration, high-energy pulsed laser beam emitted by laser 10 penetrates vertically through the transparent observation window of the lubricating oil pipe, forming a uniform illumination area. The laser wavelength is typically selected in the visible light band to balance penetration power and CMOS12 sensitivity.

[0047] As the abrasive particles flow through the illuminated area, they scatter and block the incident laser light. The scattered light carries the contour information of the abrasive particles, which is collected and focused by lens 11. The focused light signal is projected onto the image plane of CMOS 12, where a photodiode array converts the light intensity distribution into an electrical signal. Imaging magnification. From object distance Image distance Decide:

[0048] (9)

[0049] in, This is the focal length of lens 11.

[0050] The analog signal output from the CMOS12 is processed to generate digital image frames. The image resolution should meet the requirements of morphological analysis, and the frame rate should be synchronized with the laser pulses to ensure that only one abrasive grain event is captured in a single exposure.

[0051] Third, the ferromagnetic abrasive particles in the abrasive grains are attracted to the ferromagnetic abrasive particle collection and cleaning device 3 by the magnetic field force, and the detachable design of the ferromagnetic abrasive particle collection tank 13 can realize the cleaning function of ferromagnetic abrasive particles in the lubricating oil pipeline.

[0052] In the fourth step, the remaining non-ferromagnetic abrasive particles enter the second-stage inductive monitoring module 4, causing magnetic field disturbance. This leads to a negative-to-positive induced electromotive force generated in the induction coil 9 within the module. This electromotive force is then output to the system processor 7 through the lead interface of the induction coil 9 for processing, enabling real-time, online monitoring of oil particles. Finally, not only can the surface area of ​​the non-ferromagnetic abrasive particles be estimated using the pulse amplitude, but the volume of the ferromagnetic abrasive particles can also be estimated by summing the absolute values ​​of the pulse amplitudes generated by the first-stage inductive monitoring module 1. Specifically:

[0053] Step 4.1: After being adsorbed by the ferromagnetic abrasive particle collection and cleaning device 3, the remaining non-ferromagnetic abrasive particles enter the second-stage inductance monitoring module 4. Non-ferromagnetic abrasive particles (such as copper, aluminum, etc., with a relative permeability of...) When the abrasive grains pass through, the eddy current effect becomes the dominant physical process: the alternating magnetic field induces eddy currents inside the abrasive grains. The magnetic field generated by these eddy currents is opposite to the original magnetic field of the excitation coil 8, thereby weakening the magnetic flux passing through the induction coil 9.

[0054] The decrease in magnetic flux causes the induction coil 9 of the second-stage inductance monitoring module 4 to generate a bidirectional "negative-positive" pulse signal, initially negative and then positive. This induced electromotive force... It can be characterized as:

[0055] (10)

[0056] in, This represents the change in magnetic flux linkage caused by nonferromagnetic abrasive particles.

[0057] For a spherical nonferromagnetic abrasive grain, the resulting change in inductance Represented as:

[0058] (11)

[0059] in, , , These are the number of coil turns, wire diameter, and equivalent solenoid length of the second-stage inductance monitoring module 4, respectively.

[0060] Step 4.2: Based on the multi-level inductance pulse signal, the surface area of ​​non-ferromagnetic abrasive particles and the volume of ferromagnetic abrasive particles are inverted and calculated. Specifically:

[0061] When ferromagnetic and non-ferromagnetic abrasive particles mix and pass through the first-stage inductance monitoring module 1, the total pulse amplitude output by its induction coil 9 is the algebraic sum of the positive and negative amplitudes of the inductance pulse signals generated by the ferromagnetic and non-ferromagnetic abrasive particles:

[0062] (12)

[0063] in, and These are the sum of the positive amplitude and the sum of the negative amplitude generated by ferromagnetic abrasive particles and non-ferromagnetic abrasive particles when passing through the first-stage inductance monitoring module 1, respectively. This indicates the total pulse amplitude output by induction coil 9.

[0064] After being adsorbed by the ferromagnetic abrasive particle collection and cleaning device, the remaining non-ferromagnetic abrasive particles enter the second-stage inductive monitoring module 4, whose induction coil 9 outputs a "negative-positive" pulse with a negative amplitude of [value missing]. ,Right now Therefore, the estimated surface area of ​​nonferromagnetic abrasive particles. for:

[0065] (13)

[0066] Ferromagnetic abrasive particle volume estimation for:

[0067] (14)

[0068] In the fifth step, non-ferromagnetic abrasive particles enter the paramagnetic magnetophoretic separation device 6. The originally uniform magnetic field generated by the magnetic poles 15 is transformed into a non-uniform gradient magnetic field under the disturbance of the ferromagnetic wires 16. Due to their different magnetic susceptibility, the paramagnetic and diamagnetic abrasive particles are subjected to magnetophoretic forces in opposite directions, causing the paramagnetic abrasive particles to enter the central outlet and the diamagnetic abrasive particles to enter the side outlet. The implementation method of the paramagnetic magnetophoretic separation device 6 can be divided into the following sub-steps:

[0069] Step 5.1: The ferromagnetic wire 16 disturbs the uniform magnetic field to form a gradient magnetic field. Specifically:

[0070] When the external uniform magnetic field (magnetic induction intensity is) When applied horizontally along the lubricating oil pipeline, a ferromagnetic wire 16 is arranged at the center of the lubricating oil pipeline along the flow direction, with high magnetic permeability ( This will distort the distribution of the magnetic field. A magnetic field can be represented as:

[0071] (15)

[0072] in, Represented in polar coordinates The magnetic field strength vector at that location; and These are the polar coordinates of the abrasive grain positions; with the center of ferromagnetic line 16 as the origin, R is the radius of ferromagnetic line 16; and These are the unit vectors in the positive directions of the x-axis and y-axis in the coordinate system, respectively; It represents the magnetic induction intensity of an external uniform magnetic field; This indicates the polar angle of the abrasive grain position relative to the center of the ferromagnetic line.

[0073] In this coordinate system, the x-axis direction is consistent with the direction of the initial uniform magnetic field, and the y-axis direction is perpendicular to magnetic pole 15 and points towards the tube wall.

[0074] Step 5.2: Based on the gradient magnetic field established in Step 5.1, paramagnetic and diamagnetic abrasive grains flowing through this gradient magnetic field are subjected to magnetophore force due to their difference in magnetic susceptibility, thus achieving separation. Specifically:

[0075] The magnetophoretic force experienced by paramagnetic and diamagnetic abrasive grains is driven by the difference in magnetic susceptibility, as expressed by the following formula:

[0076] (16)

[0077] in, For magnetophoresis; That is, the difference in magnetic susceptibility between abrasive particles and lubricating oil; This refers to the volume of the abrasive grains. Permeability of free space; The gradient is the square of the magnetic field strength.

[0078] Paramagnetic abrasives (such as those containing Cr and Ni alloys), Magnetoresistance force direction and The same, that is, pointing towards the region with the strongest magnetic field (near ferromagnetic line 16), thus moving towards the center of the lubricating oil pipe; diamagnetic abrasive particles (such as copper, aluminum, Magnetoresistance force direction and Conversely, it points to the area with the weakest magnetic field (the two sides of the tube wall away from the ferromagnetic line 16).

[0079] Step 5.3, the separation efficiency of paramagnetic and diamagnetic abrasive particles is improved by using claw-shaped flow channels 17, specifically:

[0080] The claw-shaped flow channel 17 employs a 30° symmetrical branched flow channel, which maximizes separation efficiency. Its 30° branching angle ensures that the combined force of the magnetophoretic force and the fluid inertial force on the antimagnetic abrasive particles is precisely directed towards the side outlet, preventing particle retention. The straight-through design of the central outlet allows paramagnetic abrasive particles to escape the high-field region via the shortest path, reducing the risk of agglomeration. It also reduces flow resistance and energy loss, and the symmetrical branching balances the flow on both sides, avoiding localized eddies.

[0081] Step 6: As the abrasive particles pass through the second-stage inductance monitoring module 4, the generated inductance pulse signal is controlled by the FPGA module in the system processor 7 to trigger the second-stage imaging monitoring module 5. This module captures images of the imaging area within the paramagnetic-diamagnetic separation device 6, specifically the latter half of the magnetophoretic flow channel 14 and the first half of the claw-shaped flow channel 17. Through particle event flow, the image information of the abrasive particles, the inductance pulse, and the paramagnetic and diamagnetic properties of the abrasive particles are correlated one-to-one. Specifically:

[0082] Step 6.1: When the abrasive particles pass through the second-stage inductive monitoring module 4, the inductive pulse signal generated by its induction coil 9 is processed by the system processor 7 to generate a digital pulse signal, thereby determining the validity of the abrasive particle event. This is based on the lubricating oil flow rate v and the distance from the second-stage inductive monitoring module 4 to the imaging area of ​​the second-stage imaging monitoring module 5. Calculate trigger delay :

[0083] (17)

[0084] When the FPGA detects a pulse delay The laser is then triggered again to ensure that it is activated synchronously when the abrasive particles reach the imaging area.

[0085] Step 6.2: When non-ferromagnetic abrasive particles pass through the second-stage imaging monitoring module 5, image acquisition is performed on them. Specifically:

[0086] The short-duration, high-energy pulsed laser beam emitted by laser 10 penetrates vertically through the transparent observation window of the lubricating oil pipe, forming a uniform illumination area. The laser wavelength is typically selected in the visible light band to balance penetration power and CMOS12 sensitivity.

[0087] As the abrasive particles flow through the illuminated area, they scatter and block the incident laser light. The scattered light carries the contour information of the abrasive particles, which is collected and focused by lens 11. The focused light signal is projected onto the image plane of CMOS 12, where a photodiode array converts the light intensity distribution into an electrical signal. Imaging magnification. From object distance Image distance Decide:

[0088] (18)

[0089] in, This is the focal length of lens 11.

[0090] The analog signal output from the CMOS12 is processed to generate digital image frames. The image resolution should meet the requirements of morphological analysis, and the frame rate should be synchronized with the laser pulses to ensure that only one abrasive grain event is captured in a single exposure.

[0091] Step 7: After the paramagnetic abrasive particles enter their respective outlets in the paramagnetic magnetophoretic separation device 6 and are separated, they enter the collection and cleaning device at the end of the pipeline to complete the cleaning of the abrasive particles.

[0092] The beneficial effects of this invention are as follows:

[0093] (1) The multi-parameter online abrasive monitoring device designed in this invention can simultaneously acquire information from multiple abrasive particles. It can provide more information for confirming the wear severity, wear mechanism, and wear source in online abrasive monitoring through pulse signals and image information generated by multi-level sensors. At the same time, compared with traditional online abrasive monitoring sensors, it has advantages such as anti-bubble interference, high response sensitivity, ability to distinguish paramagnetic particles, and ability to verify multiple information.

[0094] (2) The abrasive monitoring method designed in this invention can be adapted to the multi-parameter online abrasive monitoring device designed in this invention. It can analyze and confirm the specific location of mechanical faults, their severity, and wear mechanisms. The triggering mechanism can eliminate bubble interference. Furthermore, the mutual comparison between monitoring modules can estimate the volume of ferromagnetic abrasive particles and the surface area of ​​non-ferromagnetic abrasive particles. The abrasive cleaning is completed by cleaning the collection tank at regular intervals, ensuring the safe and efficient operation of the equipment. Attached Figure Description

[0095] Figure 1 This is a schematic diagram of an online multi-parameter monitoring device for abrasive particles designed according to the present invention;

[0096] Figure 2 This is a top view of a paradoxical magnetophoretic separation device designed according to the present invention;

[0097] Figure 3 This is a flowchart describing the online monitoring of multiple parameters of lubricating oil abrasive particles according to the present invention.

[0098] In the diagram: 1 First-stage inductance monitoring module, 2 First-stage imaging monitoring module, 3 Ferromagnetic abrasive particle collection device, 4 Second-stage inductance monitoring module, 5 Second-stage imaging monitoring module, 6 Paramagnetic magnetophoresis separation device, 7 System processor; 8 Excitation coil, 9 Induction coil, 10 Laser, 11 Lens, 12 CMOS, 13 Ferromagnetic abrasive particle collection tank, 14 Magnetophoresis channel, 15 Magnetic pole, 16 Ferromagnetic wire, 17 Claw-shaped channel, 18 Paramagnetic abrasive particle collection tank, 19 Diamagnetic abrasive particle collection tank, 20 Filter screen. Detailed Implementation

[0099] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will be described in conjunction with the appendices in the embodiments of the present invention. Figure 1 To be continued Figure 3 The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0100] Figure 1 This is a schematic diagram of an online multi-parameter monitoring device for abrasive particles, such as... Figure 1 As shown, the device in this embodiment includes: an inductance monitoring module, an imaging monitoring module, a paradoxical magnetophoresis separation device 6, a collection and cleaning device, and a system processor 7. The inductance monitoring module is used to detect the magnetic field disturbance generated when abrasive particles pass through, generate an inductance pulse signal to obtain the size, number, and ferromagnetic properties of the abrasive particles, and transmit the signal to the system processor 7 through a wire. The imaging monitoring module is triggered by the system processor 7 according to the inductance pulse signal from the inductance monitoring module to image the abrasive particles, obtain the shape and size information of the abrasive particles, and transmit the image data to the system processor 7 again through a wire. The paradoxical magnetophoresis separation device 6 is used to separate paramagnetic and diamagnetic abrasive particles using a gradient magnetic field. Its separation process is monitored by the second-stage imaging monitoring module 5 of the inductance monitoring module and is connected to the collection and cleaning device through a flow channel. The collection and cleaning device is used to collect and clean the separated abrasive particles and is connected to the pipe outlet through a detachable design. The system processor 7 is used to receive and process signals from the inductance monitoring module, including filtering circuits, amplification circuits, A / D conversion, and an FPGA; it controls and triggers the imaging monitoring module, processes image data, calculates wear particle parameters, and coordinates communication and data flow throughout the monitoring process. Specifically:

[0101] The inductive monitoring module surrounds the outside of the lubricating oil pipe and includes a first-stage inductive monitoring module 1 and a second-stage inductive monitoring module 4 with identical structures. It is used to detect magnetic field disturbances generated when abrasive particles pass through, generating inductive pulse signals to obtain the size, number, and ferromagnetic properties of the abrasive particles. Both the first-stage and second-stage inductive monitoring modules 1 and 4 consist of three stacked planar coils, aligned at the center, sharing a common hollow circular hole for the lubricating oil pipe to pass through. The planar coils are fabricated using PCB technology, with copper wires, a thickness of 35μm, and an outer diameter of 10mm. The three planar coils include two excitation coils 8 and one induction coil 9. The induction coil 9 is located in the middle, with the two excitation coils 8 symmetrically arranged on either side. The induction coil 9 transmits the signal to the system processor 7 via wires. This design, with its integrated planar coils, achieves a highly dense and precisely symmetrical configuration of the excitation coils, which is beneficial for improving the sensor's response sensitivity.

[0102] The imaging monitoring module is located outside the lubricating oil pipeline and includes a first-stage imaging monitoring module 2 and a second-stage imaging monitoring module 5 with identical structures. Triggered by the system processor 7 based on the inductance pulse signal from the inductance monitoring module, it images the abrasive particles, acquiring their shape and size information, and transmits the image data to the system processor 7 via a wire. Both the first-stage imaging monitoring module 2 and the second-stage imaging monitoring module 5 are composed of a laser 10, a lens 11, and a CMOS sensor 12 arranged sequentially from top to bottom; the laser 10, lens 11, and CMOS sensor 12 are on the same central axis, which is perpendicular to the axis of the lubricating oil pipeline. The laser 10, located above the lubricating oil pipe, is a 532nm wavelength semiconductor pulsed laser. It is connected to the system processor 7 via a wire and triggered by an inductor pulse signal generated by the inductor monitoring module. It provides a uniform light source to illuminate the observation window on the lubricating oil pipe. The lens 11, located below the lubricating oil pipe, is an achromatic lens with a focal length of 20mm. It collects and focuses light carrying information about the contours and morphology of the abrasive grains onto the photosensitive surface of the CMOS 12. The CMOS 12, located below the lens 11 and also below the lubricating oil pipe, has a pixel size of 3.4μm and a resolution of 2 megapixels. It converts the collected photoelectric signals into a digital image of the abrasive grains, which is then transmitted to the system processor 7.

[0103] The antimagnetic magnetophoresis separation device 6 is located in the lubricating oil pipeline after the second-stage inductance monitoring module 4. It is part of the pipeline flow, and abrasive particles are separated after flowing through the antimagnetic magnetophoresis separation device 6 with the lubricating oil. Figure 2As shown, it includes a magnetic phoresis channel 14, magnetic poles 15, ferromagnetic wires 16, and claw-shaped channel 17. The magnetic phoresis channel 14 serves as the main pipe of the antimagnetic magnetic phoresis separation device 6, and is directly coaxially connected to the lubricating oil pipes at the front and rear ends to form a continuous flow path. The magnetic poles 15 are neodymium iron boron (N52) permanent magnets, symmetrically arranged on both sides of the magnetic phoresis channel 14 to form a uniform external magnetic field, located on the outer periphery of the pipe in the horizontal direction. The magnetic field generated by them penetrates the pipe wall and forms an initial uniform magnetic field inside the device. The ferromagnetic wires 16 are iron-cobalt alloy wires, arranged in the center of the magnetic phoresis channel 14 along the lubricating oil flow direction, penetrating the entire separation zone, and are used to disturb the uniform magnetic field generated by the magnetic poles 15, so that it forms a gradient magnetic field with uneven magnetic field strength around the ferromagnetic wires 16. The claw-shaped channel 17 is located at the downstream outlet end of the magnetic phoresis channel 14, is an extension of the magnetic phoresis channel 14, and is fixedly connected to the magnetic phoresis channel 14. The flow channel consists of a central outlet b and two side outlets a and c. The axis of outlet b coincides with the central axis of the lubricating oil pipe. The angle between the axis of outlet a and the axis of outlet b is 30°. The axis of outlet c is symmetrical to the axis of outlet a about the axis of outlet b. Furthermore, the axes of one inlet and three outlets are all in the same plane, forming a "chicken claw" branching structure. This special angle design ensures precise separation of paramagnetic and diamagnetic abrasive particles under the influence of magnetophore force and fluid inertial force.

[0104] The collection and cleaning device includes a ferromagnetic abrasive particle collection and cleaning device 3, a paramagnetic abrasive particle collection tank 18, and a diamagnetic abrasive particle collection tank 19. The ferromagnetic abrasive particle collection and cleaning device 3 is installed between the first-stage imaging monitoring module 2 and the second-stage inductive monitoring module 4, and is used to adsorb and clean ferromagnetic abrasive particles. The paramagnetic abrasive particle collection tank 18 is installed at the rear end of the central outlet b of the paramagnetic-diamagnetic magnetophoretic separation device 6, and its inlet is equipped with a filter screen 20 to trap paramagnetic abrasive particles while allowing lubricating oil to pass through. There are two diamagnetic abrasive particle collection tanks 19, respectively installed at the rear ends of the side outlets a and c of the paramagnetic-diamagnetic magnetophoretic separation device 6, and their inlets are also equipped with filter screens 20 to trap diamagnetic abrasive particles. Furthermore, the device can be disassembled periodically to achieve the purpose of cleaning abrasive particles.

[0105] The system processor 7 is used for signal processing and abrasive event detection, collaborative trigger control, multi-source data fusion, and parameter calculation. It includes a filtering circuit, an amplification circuit, an analog-to-digital converter (A / D converter), and a field-programmable gate array (FPGA). The filtering and amplification circuits are used to denoise and amplify the inductor pulse signal from the inductor monitoring module. The A / D converter converts the inductor pulse signal into a digital signal for subsequent digital processing. The core computing and control components of the system processor 7 are responsible for implementing high-speed digital logic, specifically for threshold comparison, trigger signal generation, precise delay control, and timestamp management.

[0106] Furthermore, in the inductance monitoring module, two excitation coils 8 are wound in opposite directions and connected in series by leads. Excitation signals are applied to both ends of the lead interface. The magnetic fields generated by the excitation coils 8 cancel each other out at the middle induction coil 9, so that the induction coil 9 is in a zero magnetic field, which increases the rate of change of magnetic flux when the abrasive particles pass through the inductance monitoring module.

[0107] Furthermore, the external magnetic field of the paramagnetic-diamagnetic separation device 6 is applied by the magnetic poles 15 placed horizontally in the lubricating oil pipe. The presence of ferromagnetic lines 16 makes the originally uniform external magnetic field non-uniform, and paramagnetic abrasive particles are attracted to the vicinity of ferromagnetic lines 16, while diamagnetic abrasive particles are pushed towards the side wall; paramagnetic abrasive particles flow out through the central outlet, and diamagnetic abrasive particles flow out through the side outlet.

[0108] Furthermore, the imaging range of the second-stage imaging monitoring module 5 covers the rear half of the magnetophoresis channel 14 and the front half of the three outlets a, b, and c of the antimagnetic magnetophoresis separation device 6, so as to achieve a one-to-one correspondence between abrasive particle images, antimagnetism, and inductive pulse signals.

[0109] A method for online multi-parameter monitoring of abrasive particles, based on the aforementioned online multi-parameter monitoring device, is used for online multi-parameter monitoring of abrasive particles. The abrasive monitoring device acquires abrasive particle passing signals and generates pulses through a first-stage inductive monitoring module 1. These pulses trigger a first-stage imaging monitoring module 2 to simultaneously acquire information on the size (wear degree) and shape (wear mechanism) of the abrasive particles. The volume is estimated by summing the absolute values ​​of the pulse amplitudes of the first-stage inductive monitoring module 1 and the second-stage inductive monitoring module 4, and this is verified against the imaging information. The second-stage inductive monitoring module 4 acquires the "negative-positive" pulses generated by remaining non-ferromagnetic abrasive particles, and analyzes the pulse amplitude to estimate their surface area. The non-uniform magnetic field disturbed by ferromagnetic wires 16 attracts paramagnetic particles to the vicinity of ferromagnetic wires 16, which are then discharged through the central outlet. Simultaneously, diamagnetic particles are pushed to the sidewall and discharged through the side outlet, thus completing the material differentiation and sorting of ferromagnetic, paramagnetic, and diamagnetic abrasive particles. Throughout the process, a triggering mechanism eliminates bubble interference, and a removable collection tank enables abrasive particle collection and cleaning. Figure 3 The flowchart below shows the specific implementation process of the online monitoring device and method, which includes the following steps:

[0110] The first step involves the abrasive particles passing through the first-stage inductive monitoring module 1, causing a magnetic field disturbance and triggering an inductive pulse signal in the induction coil 9. Utilizing the opposing effects of ferromagnetic and non-ferromagnetic particles on the original magnetic field, the output signals are out of phase, allowing for the differentiation of abrasive particle types in the lubricating oil. The output signal is then sent to the system processor 7 via the induction coil 9 lead interface. It passes through a filtering circuit and an amplification circuit, and finally is processed by an A / D converter input to the FPGA, achieving real-time, online monitoring of lubricating oil abrasive particles. The same process occurs when multiple abrasive particles pass through the first-stage inductive monitoring module 1 simultaneously; however, this method cannot differentiate between ferromagnetic and non-ferromagnetic particles, only serving a triggering function. Specifically:

[0111] Step 1.1: The two excitation coils 8 within the first-stage inductance monitoring module 1 are connected in reverse series. Under the same excitation signal, a typical excitation signal is a sine wave with a frequency of 1MHz and an amplitude of 5V. These generate two magnetic fields of equal magnitude and opposite direction in the region where the induction coil 9 is located, causing them to cancel each other out and thus establishing a background environment close to zero magnetic field. When abrasive particles pass through the first-stage inductance monitoring module 1, this equilibrium state will be significantly disturbed: ferromagnetic abrasive particles (such as steel and iron) will enhance the original magnetic field, increasing the magnetic flux of the induction coil 9; while non-ferromagnetic abrasive particles (such as copper and aluminum) will weaken the original magnetic field due to the eddy current effect, reducing the magnetic flux. By detecting the inductance pulse signal generated by the induction coil 9 through the system processor 7, the size, number, and ferromagnetic properties of the metal abrasive particles in the oil can be obtained.

[0112] Step 1.2, the inductance pulse signal and inductance change caused by the passage of a single abrasive grain, specifically:

[0113] The induced electromotive force generated by the change in magnetic flux in the induction coil circuit 9 for:

[0114] (1)

[0115] Where t represents time; Let be the flux linkage of induction coil 9. The flux linkage can be expressed as:

[0116] (2)

[0117] in, The inductance of induction coil 9; This is the induced current in induction coil 9;

[0118] The induced electromotive force can then be further expressed as:

[0119] (3)

[0120] The inductance monitoring module can be equivalent to a multi-layered, tightly wound solenoid with a length equal to the diameter of the conductor. When a relative permeability is... The change in system inductance caused by spherical abrasive grains passing through the equivalent solenoid. It can be modeled as:

[0121] (4)

[0122] in, The diameter of the wound wire; This represents the number of turns in the coil. The length of the equivalent solenoid; Permeability of free space; The radius of the spherical abrasive grain; Let be the relative permeability of the spherical abrasive grain. For typical ferromagnetic abrasive grains (such as steel chips, with a relative permeability of 100 and a radius of 25 μm), the change in inductance is calculated according to formula (4). The change is approximately 12nH, which is sufficient to be reliably captured by the detection circuit of this system.

[0123] Step 1.3, signal superposition in multi-abrasive concurrent scenarios, specifically:

[0124] When multiple abrasive particles pass through the first-stage inductive monitoring module 1 simultaneously, each abrasive particle independently disturbs the magnetic field, and the total induced electromotive force output by the induction coil 9... The linear superposition of the induced electromotive forces contributed by all individual abrasive grains:

[0125] (5)

[0126] in, The total induced electromotive force output by induction coil 9; The induced electromotive force caused by the kth abrasive grain; This represents the change in magnetic flux linkage generated on induction coil 9 caused by the kth abrasive grain; This represents the total number of abrasive particles passing through simultaneously.

[0127] Correspondingly, the change in total magnetic flux linkage of induction coil 9 Also, the algebraic sum contributed by all individual abrasive particles:

[0128] (6)

[0129] The second step involves the inductance pulse signal generated when the abrasive grains pass through the first-stage inductance monitoring module 1. This signal is controlled by the FPGA module in the system processor 7 to trigger the first-stage imaging monitoring module 2 to capture images of the shape and size of the abrasive grains. These two features correspond to the wear mechanism and the severity of wear, respectively, effectively avoiding information redundancy and eliminating bubble interference. When multiple abrasive grains pass through simultaneously, the first-stage imaging monitoring module 2 can also acquire their shape and size information. Specifically:

[0130] Step 2.1: When the abrasive particles pass through the first-stage inductance monitoring module 1, the inductance pulse signal generated by its induction coil 9 is processed by the system processor 7 (including filtering, amplification, and A / D conversion) to generate a digital pulse signal. The FPGA module of the system processor 7 sets the voltage threshold. When the absolute value of the processed inductor pulse signal amplitude satisfies When this is determined to be a valid abrasive event, the voltage threshold... The range is This threshold effectively filters out environmental electrical noise and interference signals generated by tiny bubbles, ensuring trigger reliability. (Based on lubricating oil flow rate) The distance between the imaging areas of the first-level inductance monitoring module 1 and the first-level imaging monitoring module 2 Calculate trigger delay :

[0131] (7)

[0132] in, This indicates the flow rate of the lubricating oil.

[0133] When the FPGA module within the system processor 7 detects a pulse delay... The output TTL level signal drives the laser 10 to ensure that the laser is turned on synchronously when the abrasive particles arrive at the imaging area, and to meet the abrasive particle motion blur suppression condition:

[0134] (8)

[0135] in, For abrasive grain feature size, For lubricating oil flow rate, The exposure time for laser 10 to emit laser light.

[0136] Step 2.2: When the abrasive particles pass through the first-stage imaging monitoring module 2, images of the abrasive particles are acquired. Specifically:

[0137] The short-duration, high-energy pulsed laser beam emitted by laser 10 penetrates vertically through the transparent observation window of the lubricating oil pipe, forming a uniform illumination area. The laser wavelength is typically selected in the visible light band to balance penetration power and CMOS12 sensitivity.

[0138] As the abrasive particles flow through the illuminated area, they scatter and block the incident laser light. The scattered light carries the contour information of the abrasive particles, which is collected and focused by lens 11. The focused light signal is projected onto the image plane of CMOS 12, where a photodiode array converts the light intensity distribution into an electrical signal. Imaging magnification. From object distance Image distance Decide:

[0139] (9)

[0140] in, The focal length of lens 11 is given. This system is configured with an object distance u=25mm and an image distance v=100mm, achieving a 4x optical magnification. This ensures that a 20μm abrasive grain covers more than 8 pixels on the image plane, meeting the requirements for morphological analysis.

[0141] The analog signal output from the CMOS12 is processed to generate digital image frames. The image resolution should meet the requirements of morphological analysis, and the frame rate should be synchronized with the laser pulses to ensure that only one abrasive grain event is captured in a single exposure.

[0142] Thirdly, the ferromagnetic abrasive particles in the abrasive grains are attracted to the ferromagnetic abrasive particle collection and cleaning device 3 by the magnetic field force. The detachable design of the ferromagnetic abrasive particle collection tank 13 enables the cleaning of ferromagnetic abrasive particles in the lubricating oil pipeline. This collection tank, made of stainless steel, is located above the pipeline and contains a strong permanent magnet to generate the gradient magnetic field required for adsorption. In practical applications, it can be set to remind maintenance personnel to disassemble and clean the device every 100 hours of operation or based on the accumulated inductance signal, thereby preventing the accumulation of ferromagnetic abrasive particles from affecting subsequent monitoring modules and achieving offline collection of abrasive particles.

[0143] In the fourth step, the remaining non-ferromagnetic abrasive particles enter the second-stage inductive monitoring module 4, causing magnetic field disturbance. This leads to a negative-to-positive induced electromotive force generated in the induction coil 9 within the module. This electromotive force is then output to the system processor 7 through the lead interface of the induction coil 9 for processing, enabling real-time, online monitoring of oil particles. Finally, not only can the surface area of ​​the non-ferromagnetic abrasive particles be estimated using the pulse amplitude, but the volume of the ferromagnetic abrasive particles can also be estimated by summing the absolute values ​​of the pulse amplitudes generated by the first-stage inductive monitoring module 1. Specifically:

[0144] Step 4.1: After being adsorbed by the ferromagnetic abrasive particle collection and cleaning device 3, the remaining non-ferromagnetic abrasive particles enter the second-stage inductance monitoring module 4. Non-ferromagnetic abrasive particles (such as copper, aluminum, etc., with a relative permeability of...) When the abrasive grains pass through, the eddy current effect becomes the dominant physical process: the alternating magnetic field induces eddy currents inside the abrasive grains. The magnetic field generated by these eddy currents is opposite to the original magnetic field of the excitation coil 8, thereby weakening the magnetic flux passing through the induction coil 9.

[0145] The decrease in magnetic flux causes the induction coil 9 of the second-stage inductance monitoring module 4 to generate a bidirectional "negative-positive" pulse signal, initially negative and then positive. This induced electromotive force... It can be characterized as:

[0146] (10)

[0147] in, This represents the change in magnetic flux linkage caused by nonferromagnetic abrasive particles.

[0148] For a spherical nonferromagnetic abrasive grain, the resulting change in inductance Represented as:

[0149] (11)

[0150] in, , , These are the number of coil turns, wire diameter, and equivalent solenoid length of the second-stage inductance monitoring module 4, respectively.

[0151] Step 4.2: Based on the multi-level inductance pulse signal, the surface area of ​​non-ferromagnetic abrasive particles and the volume of ferromagnetic abrasive particles are inverted and calculated. Specifically:

[0152] When ferromagnetic and non-ferromagnetic abrasive particles mix and pass through the first-stage inductance monitoring module 1, the total pulse amplitude output by its induction coil 9 is the algebraic sum of the positive and negative amplitudes of the inductance pulse signals generated by the ferromagnetic and non-ferromagnetic abrasive particles:

[0153] (12)

[0154] in, and These are the sum of the positive amplitude and the sum of the negative amplitude generated by ferromagnetic abrasive particles and non-ferromagnetic abrasive particles when passing through the first-stage inductance monitoring module 1, respectively. This indicates the total pulse amplitude output by induction coil 9.

[0155] After being adsorbed by the ferromagnetic abrasive particle collection and cleaning device, the remaining non-ferromagnetic abrasive particles enter the second-stage inductive monitoring module 4, whose induction coil 9 outputs a "negative-positive" pulse with a negative amplitude of [value missing]. ,Right now Therefore, the estimated surface area of ​​nonferromagnetic abrasive particles. for:

[0156] (13)

[0157] Ferromagnetic abrasive particle volume estimation for:

[0158] (14)

[0159] This method is particularly important in scenarios with multiple particles occurring simultaneously. Even if the imaging monitoring module cannot accurately measure a single particle due to overlap, it can still estimate the volume of ferromagnetic abrasive particles and the surface area of ​​non-ferromagnetic abrasive particles through inductive pulse signals, which can be mutually compensated and verified with the imaging results.

[0160] In the fifth step, non-ferromagnetic abrasive particles enter the paramagnetic magnetophoretic separation device 6. The originally uniform magnetic field generated by the magnetic poles 15 is transformed into a non-uniform gradient magnetic field under the disturbance of the ferromagnetic wires 16. Due to their different magnetic susceptibility, the paramagnetic and diamagnetic abrasive particles are subjected to magnetophoretic forces in opposite directions, causing the paramagnetic abrasive particles to enter the central outlet and the diamagnetic abrasive particles to enter the side outlet. The implementation method of the paramagnetic magnetophoretic separation device 6 can be divided into the following sub-steps:

[0161] Step 5.1: The ferromagnetic wire 16 disturbs the uniform magnetic field to form a gradient magnetic field. Specifically:

[0162] When the external uniform magnetic field (magnetic induction intensity is) When applied horizontally along the lubricating oil pipeline, a ferromagnetic wire 16 is arranged at the center of the lubricating oil pipeline along the flow direction, with high magnetic permeability ( This will distort the distribution of the magnetic field. A magnetic field can be represented as:

[0163] (15)

[0164] in, Represented in polar coordinates The magnetic field strength vector at that location; and These are the polar coordinates of the abrasive grain positions; with the center of ferromagnetic line 16 as the origin, R is the radius of ferromagnetic line 16; and These are the unit vectors in the positive directions of the x-axis and y-axis in the coordinate system, respectively; It represents the magnetic induction intensity of an external uniform magnetic field; This indicates the polar angle of the abrasive grain position relative to the center of the ferromagnetic line.

[0165] In this coordinate system, the x-axis direction is aligned with the initial uniform magnetic field direction, and the y-axis direction is perpendicular to magnetic pole 15 and points towards the tube wall. In the numerical simulation, the radius of the ferromagnetic wire is set to R = 0.25 mm, and the external magnetic field strength is 0.5 T. At a distance of 10 μm from the surface of the ferromagnetic wire, the magnetic field gradient can reach [value missing]. It can be seen that the magnetic field gradient is the largest near the surface of the ferromagnetic wires, which provides the key driving force for magnetophoretic separation.

[0166] Step 5.2: Based on the gradient magnetic field established in Step 5.1, paramagnetic and diamagnetic abrasive grains flowing through this gradient magnetic field are subjected to magnetophore force due to their difference in magnetic susceptibility, thus achieving separation. Specifically:

[0167] The magnetophoretic force experienced by paramagnetic and diamagnetic abrasive grains is driven by the difference in magnetic susceptibility, as expressed by the following formula:

[0168] (16)

[0169] in, For magnetophoresis; That is, the difference in magnetic susceptibility between abrasive particles and lubricating oil; This refers to the volume of the abrasive grains. Permeability of free space; The gradient is the square of the magnetic field strength.

[0170] Paramagnetic abrasives (such as those containing Cr and Ni alloys), Magnetoresistance force direction and The same, that is, pointing towards the region with the strongest magnetic field (near ferromagnetic line 16), thus moving towards the center of the lubricating oil pipe; diamagnetic abrasive particles (such as copper, aluminum, Magnetoresistance force direction and Conversely, it points to the area with the weakest magnetic field (the two sides of the tube wall away from the ferromagnetic line 16).

[0171] Step 5.3, the separation efficiency of paramagnetic and diamagnetic abrasive particles is improved by using claw-shaped flow channels 17, specifically:

[0172] The claw-shaped flow channel 17 employs a 30° symmetrical branched flow channel, which maximizes separation efficiency. Its 30° branching angle ensures that the combined force of the magnetophoretic force and the fluid inertial force on the antimagnetic abrasive particles is precisely directed towards the side outlet, preventing particle retention. The straight-through design of the central outlet allows paramagnetic abrasive particles to escape the high-field region via the shortest path, reducing the risk of agglomeration. It also reduces flow resistance and energy loss, and the symmetrical branching balances the flow on both sides, avoiding localized eddies.

[0173] Step 6: As the abrasive particles pass through the second-stage inductance monitoring module 4, the generated inductance pulse signal is controlled by the FPGA module in the system processor 7 to trigger the second-stage imaging monitoring module 5. This module captures images of the imaging area within the paramagnetic-diamagnetic separation device 6, specifically the latter half of the magnetophoretic flow channel 14 and the first half of the claw-shaped flow channel 17. Through particle event flow, the image information of the abrasive particles, the inductance pulse, and the paramagnetic and diamagnetic properties of the abrasive particles are correlated one-to-one. Specifically:

[0174] Step 6.1: When the abrasive particles pass through the second-stage inductive monitoring module 4, the inductive pulse signal generated by its induction coil 9 is processed by the system processor 7 to generate a digital pulse signal, thereby determining the validity of the abrasive particle event. This is based on the lubricating oil flow rate v and the distance from the second-stage inductive monitoring module 4 to the imaging area of ​​the second-stage imaging monitoring module 5. Calculate trigger delay :

[0175] (17)

[0176] When the FPGA detects a pulse delay The laser is then triggered again to ensure that it is activated synchronously when the abrasive particles reach the imaging area.

[0177] Step 6.2: When non-ferromagnetic abrasive particles pass through the second-stage imaging monitoring module 5, image acquisition is performed on them. Specifically:

[0178] The short-duration, high-energy pulsed laser beam emitted by laser 10 penetrates vertically through the transparent observation window of the lubricating oil pipe, forming a uniform illumination area. The laser wavelength is typically selected in the visible light band to balance penetration power and CMOS12 sensitivity.

[0179] As the abrasive particles flow through the illuminated area, they scatter and block the incident laser light. The scattered light carries the contour information of the abrasive particles, which is collected and focused by lens 11. The focused light signal is projected onto the image plane of CMOS 12, where a photodiode array converts the light intensity distribution into an electrical signal. Imaging magnification. From object distance Image distance Decide:

[0180] (18)

[0181] in, Let be the focal length of lens (11);

[0182] The analog signal output from the CMOS12 is processed to generate digital image frames. The image resolution should meet the requirements of morphological analysis, and the frame rate should be synchronized with the laser pulses to ensure that only one abrasive grain event is captured in a single exposure.

[0183] In the seventh step, after the paramagnetic abrasive particles enter their respective outlets in the paramagnetic magnetophoretic separation device 6 and complete separation, they enter the collection and cleaning device at the end of the pipeline to complete the abrasive particle cleaning. The filter screens 20 at the inlets of the paramagnetic abrasive particle collection tank 18 and the diamagnetic abrasive particle collection tank 19 can effectively trap their respective target abrasive particles. These collection tanks all adopt a quick-release interface design, which allows maintenance personnel to easily disassemble them according to the system's preset maintenance cycle or the warning signal issued by the processor based on the abrasive particle count, in order to clean the collected abrasive particle samples and perform subsequent offline analysis. At the same time, it restores the permeability of the filter screens, ensuring that the monitoring device can operate continuously and stably for a long time.

[0184] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-parameter online monitoring device for abrasive particles, characterized in that, The multi-parameter online abrasive monitoring device includes an inductance monitoring module, an imaging monitoring module, a para-anamagnetic magnetophoretic separation device (6), a collection and cleaning device, and a system processor (7); The inductance monitoring module is used to detect the magnetic field disturbance generated when the abrasive particles pass through, obtain the size, number and ferromagnetic properties of the abrasive particles, and transmit the signal to the system processor (7) through a wire; the imaging monitoring module is triggered by the system processor (7) according to the inductance pulse signal of the inductance monitoring module, to image the abrasive particles, obtain the shape and size information of the abrasive particles, and transmit the image data to the system processor (7) through a wire; the paramagnetic and diamagnetic separation device (6) is used to separate paramagnetic and diamagnetic abrasive particles using a gradient magnetic field. Its separation process is monitored by the second-level imaging monitoring module (5) of the inductance monitoring module and is connected to the collection and cleaning device through the flow channel; the collection and cleaning device is used to collect and clean the separated abrasive particles and is connected to the pipe outlet; the system processor (7) is used to receive and process the signal of the inductance monitoring module, control the triggering of the imaging monitoring module, process the image data, and calculate the abrasive particle parameters.

2. The online multi-parameter monitoring device for abrasive particles according to claim 1, characterized in that, The inductance monitoring module surrounds the outside of the lubricating oil pipe and includes a first-stage inductance monitoring module (1) and a second-stage inductance monitoring module (4) with the same structure. It is used to detect the magnetic field disturbance generated when abrasive particles pass through. The first-stage inductance monitoring module (1) and the second-stage inductance monitoring module (4) are both composed of three planar coils stacked together. The three coils are aligned at the center and have a common hollow circular hole for the lubricating oil pipe to pass through. The three planar coils include two excitation coils (8) and one induction coil (9). The induction coil (9) is located in the middle, and the two excitation coils (8) are symmetrically arranged on both sides. The induction coil (9) transmits the signal to the system processor (7) through a wire.

3. The online multi-parameter monitoring device for abrasive particles according to claim 2, characterized in that, In the inductance monitoring module, two excitation coils (8) are wound in opposite directions and connected in series by leads. An excitation signal is applied to both ends of the lead interface. The magnetic fields generated by the excitation coils (8) cancel each other out at the middle induction coil (9), so that the induction coil (9) is in a zero magnetic field.

4. The online multi-parameter monitoring device for abrasive particles according to claim 2, characterized in that, The imaging monitoring module is located outside the lubricating oil pipeline and includes a first-level imaging monitoring module (2) and a second-level imaging monitoring module (5) with the same structure. The first-level imaging monitoring module (2) and the second-level imaging monitoring module (5) are both composed of a laser (10), a lens (11) and a CMOS (12) arranged from top to bottom. The laser (10), lens (11) and CMOS (12) are on the same central axis, which is perpendicular to the axis of the lubricating oil pipe. The laser (10) is located above the lubricating oil pipe and is connected to the system processor (7). It is triggered by the inductance pulse signal generated by the inductance monitoring module and is used to provide a uniform light source. The lens (11) is located below the lubricating oil pipe. The CMOS (12) is located below the lens (11) and also below the lubricating oil pipe. It is used to convert the collected photoelectric signals into digital images of abrasive particles and then transmit them to the system processor (7).

5. The online multi-parameter monitoring device for abrasive particles according to claim 3, characterized in that, The antimagnetic magnetophoresis separation device (6) is located in the lubricating oil pipeline after the second-stage inductance monitoring module (4). The abrasive particles are separated after passing through the antimagnetic magnetophoresis separation device (6) with the lubricating oil. The device includes a magnetophoresis channel (14), a magnetic pole (15), a ferromagnetic wire (16), and a claw-shaped channel (17). The magnetophoresis channel (14) serves as the main pipe of the antimagnetic magnetophoresis separation device (6), and is directly coaxially connected to the lubricating oil pipes at the front and rear ends to form a continuous flow path. The magnetic poles (15) are symmetrically arranged on both sides of the magnetophoresis channel (14) to form a uniform external magnetic field, which is located on the outer periphery of the horizontal direction of the pipe to form an initial uniform magnetic field. The ferromagnetic wires (16) are arranged in the center of the magnetophoresis channel (14) along the lubricating oil flow direction, penetrating the entire separation zone, and are used to disturb the uniform magnetic field generated by the magnetic poles (15) so that a gradient magnetic field with uneven magnetic field strength is formed around the ferromagnetic wires (16). The claw-shaped channel (17) is located at the downstream outlet end of the magnetophoresis channel (14) and is connected to the magnetophoresis channel (14).

6. The online multi-parameter monitoring device for abrasive particles according to claim 4, characterized in that, The collection and cleaning device includes a ferromagnetic abrasive particle collection and cleaning device (3), a paramagnetic abrasive particle collection tank (18), and a diamagnetic abrasive particle collection tank (19); The ferromagnetic abrasive particle collection and cleaning device (3) is installed between the first-level imaging monitoring module (2) and the second-level inductive monitoring module (4); the paramagnetic abrasive particle collection tank (18) is installed at the rear end of the central outlet of the paramagnetic antimagnetic magnetophoretic separation device (6), and a filter screen (20) is provided at its inlet to trap paramagnetic abrasive particles and allow lubricating oil to pass through; the antimagnetic abrasive particle collection tank (19) is installed at the rear end of the side outlet of the paramagnetic antimagnetic magnetophoretic separation device (6), and a filter screen (20) is also provided at its inlet to trap antimagnetic abrasive particles.

7. The online multi-parameter monitoring device for abrasive particles according to claim 5, characterized in that, The system processor (7) is used for signal processing and abrasive event detection, collaborative trigger control, multi-source data fusion and parameter calculation, including a filter circuit, an amplifier circuit, an analog-to-digital converter and a field-programmable gate array (FPGA); the filter circuit and the amplifier circuit are used to denoise and amplify the inductor pulse signal transmitted from the inductor monitoring module; the analog-to-digital converter is used to convert the inductor pulse signal into a digital signal; the system processor (7) is used for threshold comparison, trigger signal generation, precise delay control and timestamp management.

8. The online multi-parameter monitoring device for abrasive particles according to claim 7, characterized in that, The imaging range of the second-level imaging monitoring module (5) covers the rear half of the magnetophoresis channel (14) and the front half of the three outlets of the antimagnetic magnetophoresis separation device (6) to achieve the correspondence between abrasive images, antimagnetism and inductive pulse signals.

9. A method for online monitoring of multiple parameters of abrasive particles based on the online monitoring device for multiple parameters of abrasive particles according to any one of claims 1-8, characterized in that, Specifically, the following steps are included: First, when abrasive particles pass through the first-stage inductive monitoring module (1), the induction coil (9) generates an inductive pulse signal, which can distinguish the type of abrasive particles in the lubricating oil; the inductive pulse signal is output to the system processor (7) to realize real-time, online monitoring of abrasive particles in the lubricating oil; specifically: Step 1.1: Under the same excitation signal, the two excitation coils (8) establish a zero magnetic field background environment; when abrasive particles pass through the first-stage inductance monitoring module (1): ferromagnetic abrasive particles enhance the original magnetic field, increasing the magnetic flux of the induction coil (9); non-ferromagnetic abrasive particles reduce the magnetic flux; the inductance pulse signal generated by the induction coil (9) is detected by the system processor (7) to obtain the size, number, and ferromagnetic properties of the metal abrasive particles in the oil. Step 1.2, the inductance pulse signal and inductance change caused by the passage of a single abrasive grain, specifically: The induced electromotive force generated in the circuit of the induction coil (9) by the change in magnetic flux for: （1） Where t represents time; Let be the flux linkage of the induction coil (9), which is expressed as: （2） in, The inductance of the induction coil (9); The current induced by the induction coil (9); The induced electromotive force can then be further expressed as: （3） The inductance monitoring module is equivalent to a multi-layered tightly wound solenoid with a length equal to the diameter of the conductor; when a relative permeability is The change in system inductance caused by spherical abrasive particles passing through an equivalent solenoid. The model is as follows: （4） in, The diameter of the wound wire; This represents the number of turns in the coil. The length of the equivalent solenoid; Permeability of free space; The radius of the spherical abrasive grain; The relative permeability of spherical abrasive grains; Step 1.3, signal superposition in multi-abrasive concurrent scenarios, specifically: When multiple abrasive particles pass through the first-stage inductive monitoring module (1) simultaneously, each abrasive particle independently disturbs the magnetic field, and the total induced electromotive force output by the induction coil (9) The linear superposition of the induced electromotive forces contributed by all individual abrasive grains: （5） in, The total induced electromotive force output by the induction coil (9); The induced electromotive force caused by the kth abrasive grain; The change in magnetic flux linkage generated on the induction coil (9) caused by the kth abrasive grain; This represents the total number of abrasive particles passing through simultaneously. Correspondingly, the change in total magnetic flux linkage of the induction coil (9) Also, the algebraic sum contributed by all individual abrasive particles: （6） The second step involves the inductance pulse signal generated when the abrasive particles pass through the first-level inductance monitoring module (1), which triggers the first-level imaging monitoring module (2) via the system processor (7) to capture images of the shape and size of the abrasive particles. When multiple abrasive particles pass through simultaneously, the first-level imaging monitoring module (2) can acquire their shape and size information. Specifically: Step 2.1: When the abrasive particles pass through the first-stage inductance monitoring module (1), the inductance pulse signal generated by its induction coil (9) is converted into a digital pulse signal by the system processor (7); the FPGA module of the system processor (7) sets the voltage threshold. When the absolute value of the processed inductor pulse signal amplitude satisfies When this occurs, it is determined to be a valid abrasive event; based on the lubricating oil flow rate... The distance between the imaging area of ​​the first-level inductance monitoring module (1) and the first-level imaging monitoring module (2) Calculate trigger delay : （7） in, Indicates the lubricating oil flow rate; When the FPGA module in the system processor (7) detects a pulse delay The output TTL level signal drives the laser (10) to ensure that the laser is turned on synchronously when the abrasive particles arrive at the imaging area, and to meet the abrasive particle motion blur suppression condition: （8） in, For abrasive grain feature size, For lubricating oil flow rate, Exposure time for the laser (10) to emit laser light; Step 2.2: When the abrasive particles pass through the first-stage imaging monitoring module (2), images of the abrasive particles are acquired. Specifically: The short-duration high-energy pulsed laser beam emitted by the laser (10) penetrates vertically through the transparent observation window of the lubricating oil pipe, forming a uniform illumination area; When the abrasive particles flow through the illumination area, they scatter and block the incident laser light; the scattered light carries the contour information of the abrasive particles, which is collected and focused by the lens (11); the focused light signal is projected onto the CMOS (12) image plane, and the photodiode array converts the light intensity distribution into an electrical signal; the imaging magnification... From object distance Image distance Decide: （9） in, Let be the focal length of lens (11); The analog signal output by CMOS(12) is processed to generate a digital image frame, and a single exposure captures a single abrasive event; The third step is that the ferromagnetic abrasive particles in the abrasive particles are adsorbed into the ferromagnetic abrasive particle collection and cleaning device (3) by the magnetic field force, and the ferromagnetic abrasive particles in the lubricating oil pipeline are cleaned through the ferromagnetic abrasive particle collection tank (13). Fourth, the remaining non-ferromagnetic abrasive particles enter the second-stage inductive monitoring module (4), causing magnetic field disturbance, which leads to the generation of a negative-positive induced electromotive force in the induction coil (9) within it, which is output to the system processor (7) for processing, realizing real-time, online monitoring of oil particles; finally, the sum of the surface areas of the non-ferromagnetic abrasive particles is estimated by the pulse amplitude, and the volume of the ferromagnetic abrasive particles is estimated by summing the absolute values ​​of the corresponding pulse amplitudes generated by the first-stage inductive monitoring module (1); specifically: Step 4.1 After being adsorbed by the ferromagnetic abrasive collection and cleaning device (3), the remaining non-ferromagnetic abrasive particles enter the second-stage inductive monitoring module (4). When the non-ferromagnetic abrasive particles pass through, their eddy current effect becomes the dominant physical process: the alternating magnetic field induces eddy currents inside the abrasive particles. The magnetic field generated by this eddy current is opposite to the original magnetic field of the excitation coil (8), weakening the magnetic flux passing through the induction coil (9). The decrease in magnetic flux causes the induction coil (9) of the second-stage inductance monitoring module (4) to generate a negative-positive bidirectional pulse signal, which is first negative and then positive; this induced electromotive force Characterized as: （10） in, The change in magnetic flux linkage caused by nonferromagnetic abrasive particles; For a spherical nonferromagnetic abrasive grain, the resulting change in inductance Represented as: （11） in, , , The coil turns, wire diameter, and equivalent solenoid length of the second-stage inductance monitoring module (4) are respectively. Step 4.2: Based on the multi-level inductance pulse signal, the surface area of ​​non-ferromagnetic abrasive particles and the volume of ferromagnetic abrasive particles are inverted and calculated. Specifically: When ferromagnetic abrasive particles and non-ferromagnetic abrasive particles are mixed and pass through the first-stage inductance monitoring module (1), the total pulse amplitude output by its induction coil (9) is the algebraic sum of the positive and negative amplitudes of the inductance pulse signals generated by the ferromagnetic and non-ferromagnetic abrasive particles: （12） in, and These are the sum of the positive amplitude and the sum of the negative amplitude generated by ferromagnetic abrasive particles and non-ferromagnetic abrasive particles when they pass through the first-stage inductance monitoring module (1), respectively. This indicates the total pulse amplitude output by the induction coil (9); After being adsorbed by the ferromagnetic abrasive particle collection and cleaning device, the remaining non-ferromagnetic abrasive particles enter the second-stage inductive monitoring module (4), whose induction coil (9) outputs a negative-positive pulse with a negative amplitude of ,Right now Therefore, the estimated surface area of ​​nonferromagnetic abrasive particles is as follows: for: （13） Ferromagnetic abrasive particle volume estimation for: （14） Fifth step: Non-ferromagnetic abrasive particles enter the paramagnetic-diamagnetic magnetophoretic separation device (6), where a non-uniform gradient magnetic field is formed under the disturbance of the ferromagnetic wires (16). Paramagnetic abrasive particles enter the central outlet, while diamagnetic abrasive particles enter the side outlet; specifically: Step 5.1: The ferromagnetic wire (16) disturbs the uniform magnetic field to form a gradient magnetic field, specifically: When a uniform external magnetic field is applied horizontally along the lubricating oil pipeline, a ferromagnetic wire (16) is arranged at the center of the pipeline along the flow direction, and its high permeability distorts the magnetic field distribution; the magnetic field is represented as: （15） in, Represented in polar coordinates The magnetic field strength vector at that location; and These are the polar coordinates of the abrasive grain positions; with the center of the ferromagnetic line (16) as the origin, R is the radius of the ferromagnetic line (16); and These are the unit vectors in the positive directions of the x-axis and y-axis in the coordinate system, respectively; It represents the magnetic induction intensity of an external uniform magnetic field; This indicates the polar angle of the abrasive grain position relative to the center of the ferromagnetic line; Among them, the x-axis direction is consistent with the initial uniform magnetic field direction, and the y-axis direction is perpendicular to the magnetic pole (15) and points to the tube wall; Step 5.2: Based on the gradient magnetic field established in Step 5.1, paramagnetic and diamagnetic abrasive particles flowing through this gradient magnetic field are separated by magnetophore force due to their difference in magnetic susceptibility; specifically: The magnetophoretic force experienced by paramagnetic and diamagnetic abrasive grains is driven by the difference in magnetic susceptibility, as expressed by the following formula: （16） in, For magnetophoresis; That is, the difference in magnetic susceptibility between abrasive particles and lubricating oil; This refers to the volume of the abrasive grains. Permeability of free space; The gradient is the square of the magnetic field strength; Magnetophoretic force on paramagnetic abrasive grains direction and The same, that is, pointing to the region of strongest magnetic field, thus moving towards the center of the lubricating oil pipe; the magnetophoretic force on the diamagnetic abrasive particles. direction and Conversely, it points to the region where the magnetic field is weakest. Step 5.3, improve the separation efficiency of paramagnetic abrasive particles and diamagnetic abrasive particles by using claw-shaped flow channels (17); Step 6: When the abrasive particles pass through the second-stage inductance monitoring module (4), the generated inductance pulse signal triggers the second-stage imaging monitoring module (5) through the system processor (7) to capture images of the imaging area within the paramagnetic-diamagnetic separation device (6), the latter half of the magnetophoretic flow channel (14), and the first half of the claw-shaped flow channel (17). Through the particle event flow, the image information of the abrasive particles, the inductance pulse, and the paramagnetism and diamagnetic properties of the abrasive particles are made to correspond one-to-one; specifically: Step 6.1: When the abrasive particles pass through the second-stage inductance monitoring module (4), the inductance pulse signal generated by its induction coil (9) is processed by the system processor (7) to generate a digital pulse signal, thereby determining the validity of the abrasive particle event; based on the lubricating oil flow rate... v Distance between the second-level inductance monitoring module (4) and the imaging area of ​​the second-level imaging monitoring module (5) Calculate trigger delay : （17） When the FPGA detects a pulse delay The laser is then triggered again to ensure that it is activated synchronously when the abrasive particles reach the imaging area; Step 6.2: When non-ferromagnetic abrasive particles pass through the second-stage imaging monitoring module (5), image acquisition is performed on them. Specifically: The short-duration high-energy pulsed laser beam emitted by the laser (10) penetrates vertically through the transparent observation window of the lubricating oil pipe, forming a uniform illumination area; When the abrasive particles flow through the illumination area, they scatter and block the incident laser light; the scattered light carries the contour information of the abrasive particles, which is collected and focused by the lens (11); the focused light signal is projected onto the CMOS (12) image plane, and the photodiode array converts the light intensity distribution into an electrical signal; the imaging magnification... From object distance Image distance Decide: （18） in, Let be the focal length of lens (11); The analog signal output by CMOS (12) is processed to generate a digital image frame, and only one abrasive event is captured in a single exposure; Step 7: After the paramagnetic abrasive particles enter their respective outlets in the paramagnetic magnetophoretic separation device (6) and are separated, they enter the collection and cleaning device at the end of the pipeline to complete the cleaning of the abrasive particles.

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