A Method and System for Closed-Loop Lubrication Control of Motors Based on Multi-Physical Quantity Edge Computation

Abstract

This invention discloses a closed-loop lubrication control method and system for motors based on multi-physical quantity edge computing, relating to the field of industrial equipment condition monitoring and maintenance technology. The invention includes: synchronously acquiring at least vibration, ultrasonic, and current signals during motor operation using the same hardware clock source, and performing whole-cycle truncation processing on the vibration and ultrasonic signals; performing FFT spectrum analysis on the processed vibration and ultrasonic signals, and calculating the proportion coefficient η of high-frequency energy to total energy based on the spectrum analysis results; and correcting the high-frequency energy proportion coefficient η according to the real-time current and speed of the motor to obtain a lubrication health index HI that eliminates load interference. This invention achieves quantitative assessment of motor lubrication health and intelligent closed-loop grease injection control through microsecond-level synchronous acquisition of multiple physical quantities and high-frequency energy analysis, avoiding over-lubrication and under-lubrication, and significantly improving equipment reliability and maintenance accuracy.

Description

Technical Field

[0001] This invention relates to the field of industrial equipment condition monitoring and maintenance technology, specifically to a motor closed-loop lubrication control method and system based on multi-physical quantity edge computing. Background Technology

[0002] As a core power source in industrial production, the reliability of electric motors directly affects the continuity and safety of production lines. Bearings, as critical load-bearing components of motors, are significantly affected by their lubrication condition, which is a major factor influencing motor lifespan and energy efficiency. Therefore, real-time monitoring of motor operating status and precise bearing lubrication maintenance have always been important issues in the field of intelligent operation and maintenance of industrial equipment.

[0003] Currently, the motor condition monitoring and lubrication maintenance solutions commonly used in the industry have the following technical shortcomings: Insufficient multi-parameter synchronization accuracy: Existing monitoring equipment typically uses independent data acquisition modules, and there is a lack of precise clock synchronization mechanism between the sensors, which makes it impossible to accurately capture the phase relationship of high-frequency signals such as vibration and ultrasound, making it difficult to achieve early fault diagnosis based on the fusion of multiple physical quantities.

[0004] Difficulty in quantifying lubrication status: Bearing lubrication status is a key indicator for motor maintenance. Existing technologies mostly determine lubrication needs by timed grease injection or simple vibration amplitude thresholds, lacking quantitative assessment methods for the lubrication film status. This can easily lead to over-lubrication or under-lubrication, and it is impossible to distinguish between poor lubrication and bearing mechanical damage.

[0005] Weak electromagnetic interference suppression capability: There is strong electromagnetic interference (high voltage and high current sudden change) inside the motor junction box. When existing monitoring equipment places the precision analog circuit in this environment, the signal-to-noise ratio drops significantly, making it difficult to extract weak early fault characteristics.

[0006] Open-loop maintenance mode: Most existing automatic grease injection devices operate independently at set times or are separate from the monitoring system, making it impossible to perform closed-loop control based on the real-time status of the bearing. They also lack a mechanism to verify the grease injection effect, which poses a maintenance risk.

[0007] Therefore, this invention proposes a closed-loop lubrication control method and system for motors based on edge calculation of multiple physical quantities. Summary of the Invention

[0008] The purpose of this invention is to provide a motor closed-loop lubrication control method and system based on multi-physical quantity edge computing, which can achieve high-precision synchronous sensing of multi-physical quantities, intelligent lubrication status diagnosis and accurate and reliable closed-loop maintenance control, thereby improving the intelligence level and reliability of motor operation and maintenance.

[0009] According to a first aspect of the present invention, in order to achieve the above-mentioned objective, the present invention provides the following technical solution: a closed-loop lubrication control method for a motor based on multi-physical quantity edge computing, applied to a PolyCloud Box terminal, comprising the following steps: Based on the same hardware clock source, at least vibration signals, ultrasonic signals and current signals during motor operation are synchronously acquired, and the vibration signals and ultrasonic signals are truncated for an entire cycle. FFT spectrum analysis was performed on the processed vibration and ultrasonic signals. Based on the spectrum analysis results, the proportion coefficient η of high-frequency energy to total energy was calculated. The high-frequency band includes the ultrasonic band and the vibration high-frequency band. Based on the real-time current and speed of the motor, the high-frequency energy proportion coefficient η is corrected to obtain the lubrication health index HI that eliminates load interference. A three-level over-limit threshold system is used to determine whether the lubrication health index (HI) exceeds the preset threshold, and a decision is made on whether to generate a grease injection control command based on the time-dose dual limit conditions and the trend of high-frequency energy change rate. After grease injection is completed, the change of the lubrication health index HI is monitored; if HI does not decrease effectively within a preset time, it is determined that there is mechanical damage to the bearing, the subsequent grease injection function is locked, and a damage alarm signal is generated.

[0010] Furthermore, based on the same hardware clock source, at least vibration signals, ultrasonic signals, and current signals are synchronously acquired during motor operation, and the vibration signals and ultrasonic signals are truncated to an integer cycle, as follows: (21) Using the zero-crossing point or peak-crossing point of the motor current signal as the main trigger reference, a synchronous sampling clock with jitter less than 1μs is generated through hardware logic circuit; (22) Based on the synchronous sampling clock, the vibration sensor is triggered at a sampling rate of 25.6kHz-51.2kHz, the ultrasonic sensor is triggered at a sampling rate of 200kHz-1MHz, and the magnetic flux leakage sensor is triggered for synchronous sampling. (23) Based on the real-time calculated motor frequency, the collected vibration signal and ultrasonic signal are subjected to whole-cycle truncation and windowing processing. The windowing adopts Hanning window or Kaiser window to ensure that the phase alignment accuracy of the multi-physical quantity spectrum analysis is less than 3.6°.

[0011] Furthermore, FFT spectrum analysis was performed on the processed vibration and ultrasonic signals, as follows: in: Represents a time-domain signal. ; Indicates the number of sampling points; Indicates the frequency index, corresponding to the actual frequency. , The sampling rate.

[0012] Furthermore, the proportion coefficient η of high-frequency energy to total energy is calculated as follows: in, The ultrasonic power spectral density is used to reflect the acoustic emission energy of a ruptured lubricating film. This refers to high-frequency vibrational energy, used to reflect metal-to-metal contact impact. This represents the total energy across the entire frequency band.

[0013] Furthermore, based on the real-time current and speed of the motor, the high-frequency energy proportion coefficient η is corrected to obtain the lubrication health index HI, which eliminates load interference, as follows: (51) Establish a baseline energy ratio based on the effective value of current I and rotational speed n in advance. Two-dimensional mapping table; (52) Calculate the lubrication health index This is to eliminate the interference of load changes on the judgment of lubrication status; (53) Set the grading judgment criteria: when HI<0.3, it is judged as good lubrication; when 0.3≤HI<0.6, it is judged as early lubrication deterioration; when HI≥0.6, it is judged as severe grease deficiency or bearing damage.

[0014] Furthermore, a three-level over-limit threshold system is used to determine whether the lubrication health index (HI) exceeds a preset threshold. Based on the time-dose dual constraint conditions and the trend of high-frequency energy change rate, a decision is made on whether to generate a grease injection control command, as detailed below: (61) Set a three-level threshold system: warning threshold HI_warn = 0.5, grease injection start threshold HI_inject = 0.7, emergency threshold HI_alarm = 0.9; When HI ≥ HI_inject, check if the following conditions are met simultaneously: High-frequency energy change rate And it continues to worsen, the current time is since the last fat injection Minimum grease injection interval; (62) The time-dose dual constraints and the trend of high-frequency energy change rate are as follows: Sliding window management: Maintains the grease injection history within a scrolling time window, including the grease injection time. and cumulative fat injection volume ; Safety lock logic: Only when the cumulative grease injection volume is met. Maximum fat injection volume per cycle and Only when this condition is met will the grease injection command be allowed to be generated; If all the conditions of steps (61) and (62) are met, a grease injection control instruction is generated; if HI ≥ HI_alarm, a grease injection control instruction is forcibly generated and alarm information is immediately uploaded.

[0015] Furthermore, the grease injection control instruction adopts a phased grease injection strategy: Phased grease injection strategy: When HI > 0.8, the rapid grease replenishment stage is executed, and the single - injection amount = 5g; Maintenance stage: When 0.5 < HI ≤ 0.8, the maintenance stage is executed, and pulsed micro - grease injection is adopted, 1g each time, with an interval of 2 hours, so that the bearing is always in the best lubricating film thickness state; Hysteresis stop mechanism: Set the dead - band threshold ΔHI = 0.2. When HI drops below 0.5 and lasts for 5 minutes, stop grease injection to prevent frequent start - stop near the critical value.

[0016] Furthermore, the closed - loop verification after grease injection includes: Continuously monitor for 30 minutes after grease injection is completed, and calculate the HI decline rate; If the HI decline rate > 30%, mark the grease injection as effective and record the grease injection history; If HI does not decline or continues to rise, combine the rotational frequency side - band characteristics in the current signal to judge the fault of the outer or inner ring of the bearing, determine it as bearing mechanical damage rather than simply lack of grease, immediately lock the grease injection function and trigger a bearing damage warning.

[0017] According to the second aspect of the present invention, the present invention provides a motor closed - loop lubrication control system based on multi - physical - quantity edge computing, which is used to implement the motor closed - loop lubrication control method based on multi - physical - quantity edge computing described in the first aspect, including: The Polyway cloud box terminal is deployed at the end of the motor or the junction box position, and specifically includes: A signal acquisition module, which is used to synchronously acquire at least vibration signals, ultrasonic signals, and current signals during the operation of the motor based on the same hardware clock source, and perform full - cycle truncation processing on the vibration signals and ultrasonic signals; An edge computing module, which is used to perform FFT spectral analysis on the processed vibration signals and ultrasonic signals, and calculate the proportion coefficient η of the high - frequency band energy in the total energy based on the spectral analysis results. The high - frequency band includes the ultrasonic frequency band and the vibration high - frequency band; A correction module, which is used to correct the high - frequency energy proportion coefficient η according to the real - time current and speed of the motor to obtain the lubrication health index HI that eliminates load interference; The control command generation module is used to determine whether the lubrication health index HI exceeds the preset threshold using a three-level over-limit threshold system, and decides whether to generate grease injection control commands based on time-dose dual constraints and high-frequency energy change rate trends. The closed-loop verification module is used to monitor the change of the lubrication health index HI after grease injection is completed; if HI does not decrease effectively within a preset time, it is determined that there is mechanical damage to the bearing, the subsequent grease injection function is locked and a damage alarm signal is generated. Grease injection actuator: Connects to the Juwei Cloud Box terminal via wired or wireless means, receives grease injection control commands and provides feedback on the execution status.

[0018] According to a third aspect of the present invention, the present invention provides a terminal device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein when the processor loads and executes the computer program, it employs the motor closed-loop lubrication control method based on multi-physical quantity edge computing described in the first aspect.

[0019] The present invention has at least the following beneficial effects: 1. This invention achieves precise phase alignment of multiple physical quantity signals such as sound, vibration, magnetic leakage, current, and temperature through a microsecond-level hardware synchronization architecture and full-cycle signal processing technology. It effectively eliminates clock drift and spectrum leakage problems in traditional multi-channel acquisition, provides a high-fidelity data foundation for early fault diagnosis, and significantly improves the accuracy of fault identification based on multi-physical quantity fusion analysis.

[0020] 2. By constructing a lubrication health index based on high-frequency energy ratio, this invention transforms the bearing lubrication status from a traditional qualitative judgment to a quantitative assessment. It can sensitively capture the critical state of the lubrication film transitioning from hydrodynamic lubrication to boundary lubrication, achieving early warning of lubrication degradation trends. This provides a reliable quantitative indicator for predictive maintenance and effectively avoids sudden downtime caused by abrupt changes in lubrication status.

[0021] 3. The time- and dosage dual-limit closed-loop grease injection strategy proposed in this invention achieves precise control of grease injection volume and intelligent decision-making on grease injection timing through sliding window management, graded threshold judgment, and hysteresis stop mechanism. While ensuring that the bearing is always at the optimal lubrication film thickness, it effectively prevents bearing temperature rise and grease waste caused by over-lubrication, significantly extends bearing service life and reduces maintenance costs.

[0022] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating the method described in this invention. Detailed Implementation

[0024] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0025] Example 1: Please see Figure 1 This invention provides a technical solution: a closed-loop lubrication control method for motors based on multi-physical quantity edge computing, comprising the following steps: S1. Based on the same hardware clock source, synchronously collect at least vibration signals, ultrasonic signals and current signals during motor operation, and perform whole-cycle truncation processing on the vibration signals and ultrasonic signals. S11. Using the zero-crossing point or peak-crossing point of the motor current signal as the main trigger reference, a synchronous sampling clock with jitter less than 1μs is generated through hardware logic circuit. S12. Based on the synchronous sampling clock, the vibration sensor is triggered at a sampling rate of 25.6kHz-51.2kHz, the ultrasonic sensor is triggered at a sampling rate of 200kHz-1MHz, and the magnetic flux leakage sensor is triggered for synchronous sampling. S13. Based on the real-time calculated motor frequency, the collected vibration signal and ultrasonic signal are subjected to whole-cycle truncation and windowing processing. The windowing adopts Hanning window or Kaiser window to ensure that the phase alignment accuracy of the multi-physical quantity spectrum analysis is less than 3.6°. S2. Perform FFT spectrum analysis on the processed vibration and ultrasonic signals, and calculate the proportion coefficient η of high-frequency energy to total energy based on the spectrum analysis results. The high-frequency band includes the ultrasonic frequency band and the vibration high-frequency band. S21. Perform FFT spectrum analysis on the processed vibration and ultrasonic signals, as follows: in: Time-domain signals (vibration or ultrasound). Number of sampling points (FFT length) Frequency index, corresponding to the actual frequency ( (sampling rate); S22. Calculate the proportion coefficient η of high-frequency energy to total energy, as follows: in, The ultrasonic power spectral density is used to reflect the acoustic emission energy of a ruptured lubricating film. This refers to high-frequency vibrational energy, used to reflect metal-to-metal contact impact. Total energy across the entire frequency band; S3. Based on the real-time current and speed of the motor, the high-frequency energy proportion coefficient η is corrected to obtain the lubrication health index HI that eliminates load interference, as follows: S31. Pre-establish a baseline energy ratio based on the effective current value I and the rotational speed n. Two-dimensional mapping table; S32. Calculate the lubrication health index This is to eliminate the interference of load changes on the judgment of lubrication status; S33. Set grading criteria: when HI < 0.3, it is judged as good lubrication; when 0.3 ≤ HI < 0.6, it is judged as early lubrication deterioration; when HI ≥ 0.6, it is judged as severe grease deficiency or bearing damage. S4. A three-level over-limit threshold system is used to determine whether the lubrication health index HI exceeds the preset threshold, and a decision is made on whether to generate a grease injection control command based on the time-dose dual limit conditions and the high-frequency energy change rate trend. S41. Set a three-level threshold system: warning threshold HI_warn = 0.5, grease injection start threshold HI_inject = 0.7, emergency threshold HI_alarm = 0.9; When HI ≥ HI_inject, check if the following conditions are met simultaneously: High-frequency energy change rate And it continues to worsen, the current time is since the last fat injection Minimum grease injection interval; S42. Time-dose dual constraints and high-frequency energy change rate trends are detailed below: Sliding window management: Maintains the grease injection history within a scrolling time window, including the grease injection time. and cumulative fat injection volume ; Safety lock logic: Only when the cumulative grease injection volume is met. Maximum fat injection volume per cycle and Only when this condition is met will the grease injection command be allowed to be generated; If all conditions in steps S41 and S42 are met, a grease injection control command is generated; if HI ≥ HI_alarm, a grease injection control command is forcibly generated and alarm information is uploaded immediately. S43. The grease injection control command adopts a staged grease injection strategy: Staged fat injection strategy: When HI > 0.8, execute the rapid fat injection stage, and the single - time fat injection volume = 5g; Maintenance stage: When 0.5 < HI ≤ 0.8, execute the maintenance stage. Adopt pulsed micro - fat injection, 1g each time, with an interval of 2 hours, so that the bearing is always in the best lubricating film thickness state; Hysteresis stop mechanism: Set the hysteresis threshold ΔHI = 0.2. When HI drops below 0.5 and lasts for 5 minutes, stop fat injection to prevent frequent start - stop near the critical value; S5. After fat injection is completed, monitor the change of the lubrication health index HI; if HI does not effectively decrease within the preset time, it is determined that there is bearing mechanical damage, lock the subsequent fat injection function and generate a damage alarm signal; The closed - loop verification after fat injection includes: Continuously monitor for 30 minutes after fat injection is completed and calculate the HI decrease rate; If the HI decrease rate > 30%, mark the fat injection as effective and record the fat injection history; If HI does not decrease or continues to rise, combine the characteristics of the rotational frequency sidebands in the current signal to judge the faults of the outer or inner ring of the bearing, and determine it as bearing mechanical damage rather than simply lack of grease. Immediately lock the fat injection function and trigger a bearing damage warning.

[0026] In summary, through the organic combination of multi - parameter synchronous acquisition, lubrication state quantitative evaluation, intelligent closed - loop control and strong anti - interference design, the present invention constructs a complete set of motor state perception and intelligent maintenance solutions, effectively solving the key problems in the prior art such as insufficient data synchronization accuracy, strong subjectivity in lubrication state evaluation, and open - loop and extensive maintenance modes, providing effective technical support for the predictive maintenance and intelligent management of industrial motors.

[0027] Embodiment 2: This embodiment provides a motor closed - loop lubrication control system based on multi - physical - quantity edge computing, used to implement the motor closed - loop lubrication control method based on multi - physical - quantity edge computing described in Embodiment 1, including: The Polywell cloud box terminal is deployed at the end of the motor or the junction box position, and specifically includes: The signal acquisition module is used to synchronously acquire at least vibration signals, ultrasonic signals and current signals during motor operation based on the same hardware clock source, and perform full - cycle truncation processing on the vibration signals and ultrasonic signals; The edge computing module is used to perform FFT spectrum analysis on the processed vibration signals and ultrasonic signals, and calculate the proportion coefficient η of the high - frequency band energy in the total energy based on the spectrum analysis results. The high - frequency band includes the ultrasonic frequency band and the vibration high - frequency band; The correction module is used to correct the high-frequency energy proportion coefficient η based on the real-time current and speed of the motor, so as to obtain the lubrication health index HI that eliminates load interference. The control command generation module is used to determine whether the lubrication health index HI exceeds the preset threshold using a three-level over-limit threshold system, and decides whether to generate grease injection control commands based on time-dose dual constraints and high-frequency energy change rate trends. The closed-loop verification module is used to monitor the change of the lubrication health index HI after grease injection is completed; if HI does not decrease effectively within a preset time, it is determined that there is mechanical damage to the bearing, the subsequent grease injection function is locked and a damage alarm signal is generated. Grease injection actuator: Connects to the PolyCloud Box terminal via wired or wireless means, receives grease injection control commands and provides feedback on the execution status; Self-powered power module: including mutual inductance power harvesting unit and / or direct power harvesting unit; The mutual inductance energy harvesting unit extracts energy from the motor bus through an open-close current transformer and charges the supercapacitor. The direct power supply unit is configured to draw power from the motor terminals and then use it after isolation and voltage reduction.

[0028] It should be noted that the edge computing module is also equipped with a low-power management strategy. When the power supply voltage is detected to be lower than the threshold, the sampling frequency is automatically reduced to maintain the core monitoring and control functions.

[0029] Example 3: This embodiment provides a terminal device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor. The memory stores the computer program capable of running on the processor. When the processor loads and executes the computer program, it adopts the motor closed-loop lubrication control method based on multi-physical quantity edge computing described in Embodiment 1.

[0030] It should be noted that the terminal device can be a computer device such as a desktop computer, a laptop computer, or a cloud server, and the terminal device includes, but is not limited to, a processor and a memory. For example, the terminal device may also include input / output devices, network access devices, and buses.

[0031] Furthermore, the processor can be a central processing unit (CPU). Of course, depending on the actual use, other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), off-the-shelf programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. can also be used. The general-purpose processor can be a microprocessor or any conventional processor, etc., and this application does not limit it in this regard.

[0032] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0033] For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances. When an element is referred to as being "assembled on," "mounted on," "fixed to," or "set on" another element, it may be directly on the other element or there may be an intermediate element present. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

[0034] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0035] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A closed-loop lubrication control method for motors based on multi-physical quantity edge computing, applied to a PolyCloud Box terminal, characterized in that, Includes the following steps: Based on the same hardware clock source, at least vibration signals, ultrasonic signals and current signals during motor operation are synchronously acquired, and the vibration signals and ultrasonic signals are truncated for an entire cycle. FFT spectrum analysis was performed on the processed vibration and ultrasonic signals. Based on the spectrum analysis results, the proportion coefficient η of high-frequency energy to total energy was calculated. The high-frequency band includes the ultrasonic band and the vibration high-frequency band. Based on the real-time current and speed of the motor, the high-frequency energy proportion coefficient η is corrected to obtain the lubrication health index HI that eliminates load interference. A three-level over-limit threshold system is used to determine whether the lubrication health index (HI) exceeds the preset threshold, and a decision is made on whether to generate a grease injection control command based on the time-dose dual limit conditions and the trend of high-frequency energy change rate. After grease injection is completed, the change of the lubrication health index HI is monitored; if HI does not decrease effectively within a preset time, it is determined that there is mechanical damage to the bearing, the subsequent grease injection function is locked, and a damage alarm signal is generated.

2. The motor closed-loop lubrication control method based on multi-physical quantity edge computing according to claim 1, characterized in that: Based on the same hardware clock source, at least vibration signals, ultrasonic signals, and current signals are synchronously acquired during motor operation, and the vibration signals and ultrasonic signals are truncated to an integer cycle, as follows: (21) Using the zero-crossing point or peak-crossing point of the motor current signal as the main trigger reference, a synchronous sampling clock with jitter less than 1μs is generated through hardware logic circuit; (22) Based on the synchronous sampling clock, the vibration sensor is triggered at a sampling rate of 25.6kHz-51.2kHz, the ultrasonic sensor is triggered at a sampling rate of 200kHz-1MHz, and the magnetic flux leakage sensor is triggered for synchronous sampling. (23) Based on the real-time calculated motor frequency, the collected vibration signal and ultrasonic signal are subjected to whole-cycle truncation and windowing processing. The windowing adopts Hanning window or Kaiser window to ensure that the phase alignment accuracy of the multi-physical quantity spectrum analysis is less than 3.6°.

3. The motor closed-loop lubrication control method based on multi-physical quantity edge computing according to claim 1, characterized in that: The processed vibration and ultrasonic signals were subjected to FFT spectrum analysis, as follows: in: Represents a time-domain signal. ; Indicates the number of sampling points; Indicates the frequency index, corresponding to the actual frequency. , The sampling rate.

4. The motor closed-loop lubrication control method based on multi-physical quantity edge computing according to claim 3, characterized in that: The proportion coefficient η of high-frequency energy to total energy is calculated as follows: in, The ultrasonic power spectral density is used to reflect the acoustic emission energy of a ruptured lubricating film. This refers to high-frequency vibrational energy, used to reflect metal-to-metal contact impact. This represents the total energy across the entire frequency band.

5. The motor closed-loop lubrication control method based on multi-physical quantity edge computing according to claim 4, characterized in that: Based on the real-time current and speed of the motor, the high-frequency energy proportion coefficient η is corrected to obtain the lubrication health index HI, which eliminates load interference, as follows: (51) Establish a baseline energy ratio based on the effective value of current I and rotational speed n in advance. Two-dimensional mapping table; (52) Calculate the lubrication health index This is to eliminate the interference of load changes on the judgment of lubrication status; (53) Set the grading judgment criteria: when HI < 0.3, it is judged as good lubrication; when 0.3 ≤ HI < 0.6, it is judged as early lubrication deterioration; when HI ≥ 0.6, it is judged as severe grease deficiency or bearing damage.

6. The motor closed-loop lubrication control method based on multi-physical quantity edge computing according to claim 5, characterized in that: A three-level over-limit threshold system is used to determine whether the lubrication health index (HI) exceeds a preset threshold. Based on time-dose dual constraints and the trend of high-frequency energy change rate, a decision is made on whether to generate a grease injection control command, as detailed below: (61) Set a three-level threshold system: warning threshold HI_warn = 0.5, grease injection start threshold HI_inject = 0.7, emergency threshold HI_alarm = 0.9; When HI ≥ HI_inject, check if the following conditions are met simultaneously: High-frequency energy change rate And it continues to worsen, the current time is since the last fat injection Minimum grease injection interval; (62) The time-dose dual constraints and the trend of high-frequency energy change rate are as follows: Sliding window management: Maintains the grease injection history within a scrolling time window, including the grease injection time. and cumulative fat injection volume ; Safety lock logic: Only when the cumulative grease injection volume is met. Maximum fat injection volume per cycle and Only when this condition is met will the grease injection command be allowed to be generated; If all conditions in steps (61) and (62) are met, a grease injection control command is generated; if HI ≥ HI_alarm, a grease injection control command is forcibly generated and alarm information is uploaded immediately.

7. The motor closed-loop lubrication control method based on multi-physical quantity edge computing according to claim 6, characterized in that: The grease injection control command adopts a staged grease injection strategy: Staged fat injection strategy: When HI > 0.8, the rapid fat replenishment phase is executed, with a single injection volume of [missing value]. = 5g; Maintenance phase: When 0.5 < HI ≤ 0.8, the maintenance phase is performed, using pulsed micro-lubricant injection, 1g each time, at 2-hour intervals, to keep the bearing in the optimal lubricating film thickness state. Hysteresis stop mechanism: Set the hysteresis threshold ΔHI = 0.

2. When HI drops below 0.5 and remains below 0.5 for 5 minutes, stop grease injection to prevent frequent start-stop near the critical value.

8. The motor closed-loop lubrication control method based on multi-physical quantity edge computing according to claim 7, characterized in that: Post-greasing closed-loop verification includes: After the fat injection is completed, continuous monitoring is performed for 30 minutes to calculate the HI reduction rate. If the HI decrease rate is > 30%, mark the grease injection as effective and record the grease injection history; If HI does not decrease or continues to rise, combine the frequency sideband characteristics in the current signal to determine whether the bearing outer or inner ring is faulty, and determine that it is mechanical damage to the bearing rather than simply lack of grease. Immediately lock the grease injection function and trigger the bearing damage warning.

9. A motor closed-loop lubrication control system based on multi-physical quantity edge computing, used to implement the motor closed-loop lubrication control method based on multi-physical quantity edge computing as described in any one of claims 1 to 8, characterized in that, include: The Juwei Cloud Box terminal, deployed at the motor end or junction box location, specifically includes: The signal acquisition module is used to synchronously acquire at least vibration signals, ultrasonic signals and current signals during motor operation based on the same hardware clock source, and to perform whole-cycle truncation processing on the vibration signals and ultrasonic signals. The edge computing module is used to perform FFT spectrum analysis on the processed vibration and ultrasonic signals, and calculate the proportion coefficient η of high-frequency energy to total energy based on the spectrum analysis results. The high-frequency band includes the ultrasonic band and the vibration high-frequency band. The correction module is used to correct the high-frequency energy proportion coefficient η based on the real-time current and speed of the motor, so as to obtain the lubrication health index HI that eliminates load interference. The control command generation module is used to determine whether the lubrication health index HI exceeds the preset threshold using a three-level over-limit threshold system, and decides whether to generate grease injection control commands based on time-dose dual constraints and high-frequency energy change rate trends. The closed-loop verification module is used to monitor the change of the lubrication health index HI after grease injection is completed; if HI does not decrease effectively within a preset time, it is determined that there is mechanical damage to the bearing, the subsequent grease injection function is locked and a damage alarm signal is generated. Grease injection actuator: Connects to the Juwei Cloud Box terminal via wired or wireless means, receives grease injection control commands and provides feedback on the execution status.

10. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that, When the processor loads and executes the computer program, it employs the motor closed-loop lubrication control method based on multi-physical quantity edge computing as described in any one of claims 1 to 8.

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