Automatic control method and control system for air compressor and air compressor

Abstract

The invention discloses an automatic control method and system for an air compressor and the air compressor, and the method comprises the steps: periodically obtaining a real-time pressure value of an air storage tank and a corresponding real-time pressure increase rate after a motor is started; comparing the real-time pressure increasing rate with the target pressure increasing rate, if the real-time pressure increasing rate is smaller than the target pressure increasing rate, judging whether the power of the motor can be increased or not according to the motor temperature, the room temperature and a motor temperature rise curve, and if the power of the motor cannot be increased, judging whether the power of the motor can be increased or not; if so, sending a fault prompt. And if the real-time pressure increasing rate is greater than the target pressure increasing rate, reducing the power of the motor. By monitoring the real-time pressure increase rate of the air storage tank in real time, the actual air collection effect of the air compressor is monitored, so that the working state of the motor is adjusted in time, closed-loop control over the air compressor is achieved, the motor is effectively protected, and the service life of the air compressor is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of air compressors, and in particular to an automatic control method and control system for an air compressor, and an air compressor. Background Art

[0002] Air compressor, also known as air compressor for short, is a commonly used device for collecting and providing compressed air to pneumatic systems. The currently commonly used portable air compressor control system is simple, for example, it only has pressure regulation and automatic start and stop functions. However, in the process of daily use, due to reasons such as untimely maintenance, the air compressor will malfunction and cannot work normally. For example, the commonly used piston air compressors on the market currently use thin steel sheets to seal the air holes in the piston. The thin steel sheets will be damaged due to metal fatigue and other reasons during long-term use, resulting in the air compressor being unable to collect air normally. However, the current air compressor control system is not smart enough. When the air compressor cannot collect air normally, it cannot adjust the motor power in time to meet the air supply demand, nor can it issue a fault alarm, and cannot prompt the user that the air compressor has a fault. Summary of the invention

[0003] In order to solve the problem that the air compressor control system cannot adjust the motor working state according to the actual air supply situation of the air compressor and cannot perform fault alarm, the present application provides an air compressor automatic control method, including the following steps: S1: after the motor is started, the real-time pressure value of the air tank and the corresponding real-time pressure increase rate are periodically obtained; S2: the first absolute difference between the real-time pressure increase rate and the corresponding target pressure increase rate at the same pressure value is calculated; S3: the first absolute difference is compared with the first threshold value, if the first absolute difference is greater than the first threshold value, the real-time pressure increase rate and the target pressure increase rate are compared; S4: if the real-time pressure increase rate is less than the target pressure increase rate, whether the power of the motor can be increased is determined at least based on the motor temperature, room temperature and the motor temperature rise curve, if the power of the motor cannot be increased, a fault prompt is issued; S5: if the real-time pressure increase rate is greater than the target pressure increase rate, the power of the motor is reduced.

[0004] By monitoring the real-time pressure increase rate of the air tank in real time, the actual air collection effect of the air compressor can be monitored, so as to adjust the working state of the motor in time, realize closed-loop control of the air compressor, effectively protect the motor and increase the service life of the air compressor.

[0005] Specifically, the target pressure increase rate is obtained by the following steps: S211: pre-set multiple pressure recording points, where the pressure recording points are the pressure values ​​of the air tank; S212: select an air compressor that has not participated in the test from multiple air compressors of the same model as the test object; S213: adjust the pressure of the air tank to the designed minimum pressure value, start the motor, and record the corresponding test time point every time the pressure of the air tank reaches one of the pressure recording points until the pressure of the air tank reaches the designed maximum pressure value; S214: calculate the pressure of two adjacent pressure recording points one by one The second absolute difference of the test point, and the test interval duration of the corresponding test time point; S215: divide the second absolute difference by the test interval duration to obtain the test pressure increase rate, and mark the test pressure increase rate as the larger one of the two adjacent pressure recording points; S216: repeat steps S212 to S215, so that each pressure recording point obtains multiple corresponding test pressure increase rates; S217: calculate the average value of the test pressure increase rate corresponding to each pressure recording point, that is, obtain the target pressure increase rate corresponding to each pressure recording point. In the actual working process of the air compressor, due to different usage conditions, the actual gas collection efficiency of each air compressor is different. By conducting experiments on multiple air compressors of the same model, multiple test pressure increase rates are measured, and the target pressure increase rate is calculated based on the multiple test pressure increase rates. In the actual fault judgment process, the first threshold is introduced to filter out the reasonable fluctuations in the pressure increase rate, which can effectively avoid misjudgment of faults.

[0006] Specifically, the first threshold is obtained by the following steps: for each of the pressure recording points, the multiple test pressure increase rates corresponding to the pressure recording point obtained in step S216 are used to calculate the range of the multiple test pressure increase rates, which is the first threshold. The range can effectively cover the fluctuation of the pressure increase rate when the air compressor is working normally, and reduce the probability of misjudging the fault.

[0007] Specifically, the real-time pressure increase rate is obtained by the following steps: S221: when the pressure of the air tank reaches the pressure recording point, the corresponding actual time point is recorded; S222: the actual interval duration between two adjacent pressure recording points is calculated according to the actual time point; S223: the second absolute difference is divided by the actual interval duration to obtain the real-time pressure increase rate, and this real-time pressure increase rate is marked as the larger one of the two adjacent pressure recording points. By recording the real-time pressure increase rate at the pressure recording point, the real-time pressure increase rate can be accurately compared with the target pressure increase rate at the same pressure level to accurately determine the actual working state of the air compressor.

[0008] Furthermore, the step of issuing the fault prompt includes: S401: obtaining the real-time air intake flow of the piston inlet and the real-time air collection flow of the piston outlet; S402: calculating the third absolute difference between the real-time air intake flow and the target air intake flow, and comparing the third absolute difference with the second threshold, calculating the fourth absolute difference between the real-time air collection flow and the target air collection flow, and comparing the fourth absolute difference with the third threshold; S403: if the third absolute difference is greater than the second threshold, and the fourth absolute difference is greater than the third threshold, then issuing a piston sealing ring fault alarm, if only the third absolute difference is greater than the second threshold, then issuing an intake valve plate fault alarm, if only the fourth absolute difference is greater than the third threshold, then issuing a gas collection valve plate fault alarm. The intake valve plate, gas collection valve plate and sealing ring in the piston will cause different phenomena when they fail. By collecting different data and analyzing them, the faulty components can be accurately determined.

[0009] Specifically, the target inspiratory flow and the target air collection flow are obtained through the following steps: S501: pre-set multiple pressure recording points, and the pressure recording points are the pressure values ​​of the air tank; S502: select an air compressor that does not participate in the test from multiple air compressors of the same model as the test object; S503: adjust the pressure of the air tank to the designed minimum pressure value, start the motor, and record the corresponding test inspiratory flow and test air collection flow whenever the pressure of the air tank reaches one of the pressure recording points until the pressure of the air tank reaches the designed maximum pressure value; S504: repeat steps S502 to S503 so that each pressure recording point obtains multiple corresponding test inspiratory flows and multiple corresponding test air collection flows; S505: calculate the average value of the multiple test inspiratory flows corresponding to each pressure recording point, that is, obtain the target inspiratory flow corresponding to each pressure recording point, and calculate the average value of the multiple test air collection flows corresponding to each pressure recording point, that is, obtain the target air collection flow corresponding to each pressure recording point.

[0010] Specifically, the second threshold and the third threshold are obtained through the following steps: S601: According to the multiple test inspiratory flow rates corresponding to each of the pressure recording points obtained in step S504, the range is calculated to obtain the second threshold; S602: According to the multiple test gas collection flow rates corresponding to each of the pressure recording points obtained in step S504, the range is calculated to obtain the third threshold.

[0011] Further, in step S403, if the third absolute difference is not greater than the second threshold value, and the fourth absolute difference is not greater than the third threshold value, the gas storage system fault diagnosis is performed, including the following steps: S701: After the motor stops, the pressure value of the gas tank and the corresponding real-time pressure drop rate are periodically recorded; S702: Calculate the fifth absolute difference between the real-time pressure drop rate and the target pressure drop rate, and compare the fifth absolute difference with the fourth threshold value; S703: If the fifth absolute difference is greater than the fourth threshold value, a gas storage system fault prompt is issued. When the piston is not faulty but the air compressor still cannot collect air normally, it is necessary to determine whether the gas storage system is faulty. By comparing the rate at which the air pressure drops when the motor of the gas storage system is not working with the normal rate, it is determined whether the gas storage system is faulty.

[0012] The present application also provides an air compressor automatic control system for implementing the control method described in any one of claims 1 to 8, wherein the control system includes a data collection module, a data processing module and a control module. The data collection module is used to periodically obtain the real-time pressure value of the air storage tank and the corresponding real-time pressure increase rate. The data processing module is used to calculate the first absolute difference between the real-time pressure increase rate and the corresponding target pressure increase rate at the same pressure value, and compare the first absolute difference with a first threshold value. If the first absolute difference is greater than the first threshold value, the real-time pressure increase rate and the target pressure increase rate are compared. The control module is used to control the power of the motor or issue a fault prompt according to the result output by the data processing module.

[0013] The present application also provides an air compressor, comprising the above control system.

[0014] Technical effects and advantages of the present invention:

[0015] 1. By real-time monitoring of the real-time pressure increase rate of the air storage tank, the actual air collection effect of the air compressor can be monitored, so as to adjust the working state of the motor in time, realize closed-loop control of the air compressor, and effectively protect the motor and increase the service life of the air compressor;

[0016] 2. By comparing the absolute difference between the real-time pressure increase rate and the target pressure increase rate with the first threshold, the reasonable fluctuation of the real-time pressure increase rate of the gas storage tank is filtered out, which can effectively avoid misjudgment of the fault.

[0017] 3. By real-time monitoring of the real-time pressure increase rate of the air tank and the operating status of the motor, it is determined whether the air compressor has a fault, and then the cause of the fault is analyzed based on the specific data, giving accurate fault prompts. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A flow chart of an automatic control method provided by a first embodiment of the present invention;

[0019] Figure 2 It is a flow chart of a method for obtaining a target pressure increase rate in a first embodiment of the present invention;

[0020] Figure 3 It is a flow chart of a method for acquiring a real-time pressure increase rate in a first embodiment of the present invention;

[0021] Figure 4 This is the process of fault diagnosis in the second embodiment of the present invention;

[0022] Figure 5 A schematic diagram of a control system provided by a third embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the connection relationship between the various components of the air compressor provided in the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Embodiment 1

[0026] refer to Figure 1-3 The first embodiment of the present invention provides an automatic control method for an air compressor, comprising the following steps: S1: after the motor is started, the real-time pressure value of the air storage tank and the corresponding real-time pressure increase rate are periodically obtained; S2: the first absolute difference between the real-time pressure increase rate and the corresponding target pressure increase rate at the same pressure value is calculated; S3: the first absolute difference is compared with a first threshold value, if the first absolute difference is greater than the first threshold value, the real-time pressure increase rate and the target pressure increase rate are compared; S4: if the real-time pressure increase rate is less than the target pressure increase rate, whether the power of the motor can be increased is determined at least based on the motor temperature, the room temperature and the motor temperature rise curve, if the power of the motor cannot be increased, a fault prompt is issued; S5: if the real-time pressure increase rate is greater than the target pressure increase rate, the power of the motor is reduced.

[0027] Since there are certain differences in the production, installation and commissioning processes, and the age of each air compressor is also different, the actual pressure increase rate of the air tank may still have room for improvement when the air compressor is actually working. Or the actual pressure increase rate of the air tank does not reach the design index, so the air collection speed can be increased by increasing the power of the motor.

[0028] Specifically, the target pressure increase rate is obtained mainly by conducting experiments on multiple air compressors of the same model. During the experiment, the pressure value of the air tank can be recorded at fixed time intervals, and then the pressure increase rate between two adjacent pressure values ​​can be calculated. It is also possible to record the time point when the pressure of the air tank reaches a fixed pressure value point, and then calculate the time interval between two adjacent pressure values, and then calculate the pressure increase rate. The advantage of the former is that the pressure value recording step can be triggered regardless of whether the pressure of the air tank rises, and the pressure increase rate can be calculated. The disadvantage is that the real-time pressure increase rate cannot accurately correspond to the target pressure increase rate at the same pressure level, and it is necessary to find the target pressure increase rate closest to the pressure level of the real-time pressure increase rate, which will inevitably lead to a certain error, and the size of the error depends on the detail of the target pressure increase rate record. The advantage of the latter is that the pressure increase rate can be accurately compared with the target pressure increase rate at the same pressure level, and the disadvantage is that when the piston fails and the air tank pressure cannot be increased, the pressure value of the air tank cannot reach the recording point, and the comparison step cannot be triggered. It is necessary to add an additional fault judgment method, for example, when the next pressure value recording point is still not reached after a predetermined time interval, a fault prompt is issued.

[0029] In the first embodiment of the present application, Figure 2As shown, the target pressure increase rate is obtained by recording the time point when the pressure of the air storage tank reaches a fixed pressure value point, which specifically includes the following steps: S211: pre-set multiple pressure recording points, and the pressure recording points are the pressure values ​​of the air storage tank; S212: select an air compressor that has not participated in the test from multiple air compressors of the same model as the test object; S213: adjust the pressure of the air storage tank to the designed minimum pressure value, start the motor, and record the corresponding test time point every time the pressure of the air storage tank reaches one of the pressure recording points until the pressure of the air storage tank reaches the designed maximum pressure value; S214: one by one Calculate the second absolute difference between two adjacent pressure recording points and the test interval duration of the corresponding test time point; S215: divide the second absolute difference by the test interval duration to obtain the test pressure increase rate, and mark the test pressure increase rate as the larger one of the two adjacent pressure recording points; S216: repeat steps S212 to S215 to obtain multiple corresponding test pressure increase rates for each pressure recording point; S217: calculate the average value of the test pressure increase rate corresponding to each pressure recording point, that is, obtain the target pressure increase rate corresponding to each pressure recording point.

[0030] Specifically, in the first embodiment of the present application, the first threshold is obtained by the following steps: for each of the pressure recording points, the multiple test pressure increase rates corresponding to the pressure recording point obtained in step S216 are used to calculate the range of the multiple test pressure increase rates, which is the first threshold. The range can effectively cover the fluctuation of the pressure increase rate of the air compressor during normal operation and reduce the probability of misjudging a fault.

[0031] The first threshold value can also be represented by other statistical data of the test pressure increase rate, such as absolute deviation. The value range of the first threshold value determines the accuracy of fault judgment. When the value range of the first threshold value is small, fault prompts are more likely to appear. For some air compressors with a long service life, the pressure rise rate of the air tank during actual operation should be significantly different from the target pressure increase rate. Increasing the value range of the first threshold value can effectively avoid false alarms of faults.

[0032] Specifically, in the first embodiment, Figure 3As shown, the real-time pressure increase rate is obtained by the following steps: S221: when the pressure of the gas tank reaches the pressure recording point, record the corresponding actual time point; S222: calculate the actual interval duration of two adjacent pressure recording points according to the actual time point; S223: divide the second absolute difference by the actual interval duration to obtain the real-time pressure increase rate, and mark this real-time pressure increase rate as the larger one of the two adjacent pressure recording points. The acquisition method of the real-time pressure increase rate is the same as that of the target pressure increase rate, both of which record the corresponding time point at the preset pressure recording point and calculate the pressure increase rate according to the time interval, so that the real-time pressure increase rate can be accurately compared with the target pressure increase rate at the same pressure level, thereby improving the accuracy of fault diagnosis.

[0033] In the first embodiment, the temperature rise curve of the motor is measured by experiment, or by establishing a thermodynamic model of the motor and performing simulation analysis. When measuring the temperature rise curve of the motor, the motor should be tested under different room temperature environments to obtain the temperature rise curve of the motor under different room temperature environments. The temperature rise curve data can be stored in the control system in the form of electronic data to facilitate determining whether the motor can increase power in step S4.

[0034] Embodiment 2

[0035] In the first embodiment of the present application, when the real-time pressure increase rate is different from the target pressure increase rate by a certain amount and cannot be improved by increasing the motor power, a fault prompt will be issued. The fault prompt can be a simple prompt that the air compressor cannot work normally, or a specific fault diagnosis method can be used to determine the specific cause of the fault.

[0036] The second embodiment of the present application is improved on the basis of the first embodiment. Specifically, Figure 4 As shown, the steps of issuing the fault prompt include: S401: obtaining the real-time intake flow of the piston inlet and the real-time air collection flow of the piston outlet; S402: calculating the third absolute difference between the real-time intake flow and the target intake flow, and comparing the third absolute difference with the second threshold, calculating the fourth absolute difference between the real-time air collection flow and the target air collection flow, and comparing the fourth absolute difference with the third threshold; S403: if the third absolute difference is greater than the second threshold, and the fourth absolute difference is greater than the third threshold, a piston sealing ring fault alarm is issued; if only the third absolute difference is greater than the second threshold, an intake valve plate fault alarm is issued; if only the fourth absolute difference is greater than the third threshold, a air collection valve plate fault alarm is issued.

[0037] The basic principle of the above steps is that the intake valve plate, the air collecting valve plate and the sealing ring in the piston will cause different phenomena when they fail. By collecting different data and analyzing them, the faulty components can be accurately identified.

[0038] In particular, in step 403, if the third absolute difference is not greater than the second threshold value, and the fourth absolute difference is not greater than the third threshold value, but the real-time pressure increase rate of the gas tank is still abnormal, it may be due to a fault in the gas storage system, such as leakage in the gas storage tank itself or leakage in the joint between the gas storage tank and other equipment, etc. Therefore, it is necessary to diagnose the fault of the gas storage system, including the following steps: S701: after the motor stops, periodically record the pressure value of the gas storage tank and the corresponding real-time pressure drop rate; S702: calculate the fifth absolute difference between the real-time pressure drop rate and the target pressure drop rate, and compare the fifth absolute difference with the fourth threshold value; S703: if the fifth absolute difference is greater than the fourth threshold value, issue a gas storage system fault prompt.

[0039] In the above steps, the target air intake flow and the target air collection flow are obtained in a manner similar to the target pressure increase rate, that is, when the pressure of the air storage tank reaches a preset pressure recording point, the corresponding air intake flow and air collection flow are recorded.

[0040] Specifically, the method includes the following steps: S501: pre-set multiple pressure recording points, where the pressure recording points are the pressure values ​​of the air tank; S502: select an air compressor that has not participated in the test from multiple air compressors of the same model as the test object; S503: adjust the pressure of the air tank to the designed minimum pressure value, start the motor, and record the corresponding test inhalation flow and test air collection flow whenever the pressure of the air tank reaches one of the pressure recording points until the pressure of the air tank reaches the designed maximum pressure value; S504: repeat steps S502 to S503, so that each pressure recording point obtains multiple corresponding test inhalation flows and multiple corresponding test air collection flows; S505: calculate the average value of the multiple test inhalation flows corresponding to each pressure recording point, that is, obtain the target inhalation flow corresponding to each pressure recording point, and calculate the average value of the multiple test air collection flows corresponding to each pressure recording point, that is, obtain the target air collection flow corresponding to each pressure recording point.

[0041] Further, the second threshold is obtained through step S601: according to the multiple test inspiratory flow rates corresponding to each of the pressure recording points obtained in step S504, the range is calculated, and the second threshold is obtained; the third threshold is obtained through step S602: according to the multiple test air collection flow rates corresponding to each of the pressure recording points obtained in step S504, the range is calculated, and the third threshold is obtained.

[0042] Embodiment 3

[0043] The present application also provides an air compressor automatic control system, such as Figure 5 As shown, for implementing the control method described in any one of claims 1 to 8, the control system includes a data collection module, a data processing module and a control module. The data collection module is used to periodically obtain the real-time pressure value of the gas tank. The data processing module is used to calculate the real-time pressure increase rate corresponding to the real-time pressure value, and the first absolute difference between the real-time pressure increase rate and the target pressure increase rate corresponding to the same pressure value, and compare the first absolute difference with the first threshold value. If the first absolute difference is greater than the first threshold value, the real-time pressure increase rate and the target pressure increase rate are compared. The control module is used to control the power of the motor or issue a fault prompt according to the result output by the data processing module.

[0044] Embodiment 4

[0045] The present application also provides an air compressor, comprising the above control system.

[0046] Specifically, refer to Figure 6 The air compressor also includes: a motor, an air tank, a piston, a pressure sensor, a first flow sensor, a second flow sensor and a control component. The piston is used to supply air to the air tank. The motor is used to drive the piston to transport gas into the air tank. The motor has a temperature sensor, which is used to measure the temperature of the motor winding. The pressure sensor is used to measure the pressure of the gas in the air tank. The first flow sensor is used to measure the gas flow at the air inlet of the piston. The second flow sensor is used to measure the gas flow at the air outlet of the piston. The motor, the pressure sensor, the first flow sensor and the second flow sensor are all electrically connected to the control component.

[0047] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An automatic control method for an air compressor, characterized in that: The following steps are involved: S1: After the motor is started, the real-time pressure value of the gas storage tank and the corresponding real-time pressure increase rate are periodically obtained; S2: Calculating a first absolute difference between the real-time pressure increase rate and the target pressure increase rate corresponding to the same pressure value; S3: comparing the first absolute difference with a first threshold value, and if the first absolute difference is greater than the first threshold value, comparing the real-time pressure increase rate with the target pressure increase rate; S4: If the real-time pressure increase rate is less than the target pressure increase rate, judging whether the power of the motor can be increased at least according to the motor temperature, the room temperature and the motor temperature rise curve, and issuing a fault prompt if the power of the motor cannot be increased; S5: If the real-time pressure increase rate is greater than the target pressure increase rate, reducing the power of the motor.

2. The air compressor automatic control method according to claim 1, characterized in that: The target pressure increase rate is obtained by the following steps: S211: presetting a plurality of pressure recording points, wherein the pressure recording points are pressure values ​​of the gas storage tank; S212: Select an air compressor that has not participated in the test from multiple air compressors of the same model as a test object; S213: adjusting the pressure of the gas storage tank to the designed minimum pressure value, starting the motor, and recording the corresponding test time point each time the pressure of the gas storage tank reaches one of the pressure recording points, until the pressure of the gas storage tank reaches the designed maximum pressure value; S214: Calculating the second absolute difference between two adjacent pressure recording points and the test interval duration of the corresponding test time points one by one; S215: Dividing the second absolute difference by the test interval duration to obtain a test pressure increase rate, and marking the test pressure increase rate as a larger one of the two adjacent pressure recording points; S216: repeating steps S212 to S215, so that each of the pressure recording points obtains a plurality of corresponding test pressure increase rates; S217: Calculate the average value of the test pressure increase rate corresponding to each pressure recording point, that is, obtain the target pressure increase rate corresponding to each pressure recording point.

3. The air compressor automatic control method according to claim 2, characterized in that: The first threshold is obtained by the following steps: For each of the pressure recording points, the multiple test pressure increase rates corresponding to the pressure recording point obtained in step S216 are used to calculate the range of the multiple test pressure increase rates, which is the first threshold corresponding to the pressure recording point.

4. The air compressor automatic control method according to claim 2, characterized in that: The real-time pressure increase rate is obtained by the following steps: S221: When the pressure of the gas storage tank reaches the pressure recording point, record the corresponding actual time point; S222: Calculating the actual interval time between two adjacent pressure recording points according to the actual time point; S223: Divide the second absolute difference by the actual interval duration to obtain the real-time pressure increase rate, and mark the real-time pressure increase rate as the larger one of the two adjacent pressure recording points.

5. The air compressor automatic control method according to claim 1, characterized in that: The steps of issuing the fault prompt include: S401: Acquire the real-time air intake flow rate of the piston air inlet and the real-time air collection flow rate of the piston air outlet; S402: calculating a third absolute difference between the real-time inspiratory flow and the target inspiratory flow, and comparing the third absolute difference with the second threshold, calculating a fourth absolute difference between the real-time collected air flow and the target collected air flow, and comparing the fourth absolute difference with the third threshold; S403: If the third absolute difference is greater than the second threshold value, and the fourth absolute difference is greater than the third threshold value, a piston sealing ring fault alarm is issued; if only the third absolute difference is greater than the second threshold value, an intake valve plate fault alarm is issued; if only the fourth absolute difference is greater than the third threshold value, a gas collecting valve plate fault alarm is issued.

6. The air compressor automatic control method according to claim 5, characterized in that: The target inspiratory flow rate and the target gas collection flow rate are obtained by the following steps: S501: presetting a plurality of pressure recording points, wherein the pressure recording points are pressure values ​​of the gas storage tank; S502: Select an air compressor that has not participated in the test from multiple air compressors of the same model as a test object; S503: adjusting the pressure of the gas storage tank to the designed minimum pressure value, starting the motor, and recording the corresponding test air suction flow and test air collection flow each time the pressure of the gas storage tank reaches one of the pressure recording points, until the pressure of the gas storage tank reaches the designed maximum pressure value; S504: repeating steps S502 to S503, so that each of the pressure recording points obtains a plurality of corresponding test inspiratory flow rates and a plurality of corresponding test gas collection flow rates; S505: Calculate the average value of the multiple test inspiratory flow rates corresponding to each of the pressure recording points, that is, obtain the target inspiratory flow rate corresponding to each pressure recording point; calculate the average value of the multiple test air collection flow rates corresponding to each of the pressure recording points, that is, obtain the target air collection flow rate corresponding to each pressure recording point.

7. The air compressor automatic control method according to claim 6, characterized in that: The second threshold and the third threshold are obtained by the following steps: S601: Calculate the range of the plurality of test inspiratory flows corresponding to each of the pressure recording points obtained in step S504, to obtain the second threshold value; S602: Calculate the range of the plurality of test gas flow rates corresponding to each of the pressure recording points obtained in step S504, to obtain the third threshold.

8. The air compressor automatic control method according to claim 5, characterized in that: In step S403, if the third absolute difference is not greater than the second threshold value, and the fourth absolute difference is not greater than the third threshold value, the gas storage system fault diagnosis is performed through the following steps: S701: After the motor stops, periodically record the pressure value of the gas storage tank and the corresponding real-time pressure drop rate; S702: Calculate a fifth absolute difference between the real-time pressure drop rate and the target pressure drop rate, and compare the fifth absolute difference with a fourth threshold; S703: If the fifth absolute difference is greater than the fourth threshold, a gas storage system failure prompt is issued.

9. An automatic control system for an air compressor, characterized in that: For implementing the control method according to any one of claims 1 to 8, the control system comprises: A data collection module is used to periodically obtain the real-time pressure value of the gas storage tank and the corresponding real-time pressure increase rate; a data processing module, configured to calculate a first absolute difference between the real-time pressure increase rate and a target pressure increase rate corresponding to the same pressure value, and compare the first absolute difference with a first threshold value, and if the first absolute difference is greater than the first threshold value, compare the real-time pressure increase rate with the target pressure increase rate; The control module is used to control the power of the motor or issue a fault prompt according to the result output by the data processing module.

10. An air compressor, characterized in that: Includes the control system described in claim 9.

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