A method for self-checking the operating performance of an air compressor

Abstract

The present application aims to provide a kind of self-checking method of air compressor working performance, which can monitor the internal mechanical wear and tear and external pipeline flow resistance of air compressor in real time, report the estimated results of relevant information in real time, and through self-checking and self-reporting the health condition of air compressor, can make the after-sales end intervene in targeted maintenance work, improve the service life of the whole machine, reduce the sudden failure of air compressor, and ensure the safe operation of vehicle.The present application includes air compressor, air tank, air compressor controller, instrument and vehicle controller, external air is accessed to the air inlet of air compressor through filter, the air outlet of air compressor is accessed to air tank through dryer, air compressor is electrically connected with air compressor controller, instrument, air compressor controller, dryer and air tank are electrically connected with vehicle controller.The present application is applied to the technical field of compressor control.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of compressor control, and particularly relates to a self-checking method for working performance of an air compressor. BACKGROUND

[0002] Since the required braking force of a pure electric bus is large, the braking mode is basically air pressure braking, and therefore, an air compressor is installed on the bus to pressurize air outside the bus and deliver the air to an air cylinder on the bus for storage. Currently, the commonly used on-board air compressors mainly include a sliding vane air compressor and a piston air compressor, which are driven by a motor, and their working principles are to increase the pressure of air by forcibly reducing the volume of the air, so as to generate compressed air. Due to the structure, there is friction contact between the internal moving parts, and the longer the working time, the more serious the wear between the moving parts, and thus the air charging performance is reduced. If the air compressor and related components are not properly or timely maintained by after-sales personnel during the operation of the pure electric bus, the air charging performance of the air compressor will be further reduced, and if it is not found in time, the key components will be permanently damaged or even the whole machine will be scrapped.

[0003] The current working control method of the on-board air compressor of the pure electric bus is relatively simple, and lacks protection of the mechanical components of the pump head. Most of the control protection strategies are used to protect the controller end of the air compressor. Generally, only the input voltage and input current of the air compressor driving motor are controlled and limited, and the output speed and torque of the air compressor driving motor are not detected and controlled in real time, and the related parameters cannot form a closed loop control. In other words, the current protection control strategy for the on-board air compressor cannot detect the real-time wear condition of the internal mechanical components of the air compressor in real time, and often only when the wear is relatively serious or the moving parts are stuck and cannot work can it be processed. It is also impossible to detect the flow resistance of the intake and exhaust pipelines in real time, and only when the pipeline is seriously blocked or seriously leaking, can maintenance personnel find the fault through related troubleshooting methods. It is also impossible to objectively evaluate the working life of the air compressor, and only when it works abnormally or fails, can the fault be processed by replacing the whole machine.

[0004] A method and circuit for judging the running state of a compressor are disclosed in Chinese Patent Publication No. CN109869881A, which judges the working state of the compressor by detecting the current of the coil of a contactor or relay connected to the compressor, but cannot detect and control the output speed and torque of the compressor drive motor in real time, cannot form a closed-loop control of related parameters, and cannot detect the real-time wear of internal mechanical parts of the air compressor in real time. Therefore, it is necessary to provide a self-checking method for the working performance of an air compressor that can monitor the internal mechanical wear and external pipeline flow resistance of the air compressor in real time, report the estimated results of related information in real time, and through self-checking and self-reporting of the health condition of the air compressor, can intervene in targeted maintenance work of the air compressor in advance, improve the service life of the whole machine, reduce sudden failures of the air compressor, and ensure the safe operation of the vehicle. SUMMARY

[0005] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art, and to provide a self-checking method for the working performance of an air compressor that can monitor the internal mechanical wear and external pipeline flow resistance of the air compressor in real time, report the estimated results of related information in real time, and through self-checking and self-reporting of the health condition of the air compressor, can intervene in targeted maintenance work of the air compressor in advance, improve the service life of the whole machine, reduce sudden failures of the air compressor, and ensure the safe operation of the vehicle.

[0006] The technical solution adopted by the present application is: the present application comprises an air compressor, an air cylinder, an air compressor controller, an instrument and a vehicle controller, external air is connected to the air inlet of the air compressor through a filter, the air outlet of the air compressor is connected to the air cylinder through a dryer, the air compressor is electrically connected to the air compressor controller, the instrument, the air compressor controller, the dryer and the air cylinder are electrically connected to the vehicle controller;When the air pressure of the air cylinder is lower than a specified value, the vehicle controller sends a working enable signal to the air compressor controller, the air compressor starts to work, and the vehicle controller runs three self-checking programs, the three self-checking programs including air compressor start-up process test, air compressor charging process test and air compressor charging energy consumption test.

[0007] From the above scheme, based on the current hardware state, by optimizing the control strategy of the software end, the internal mechanical wear and tear and external pipeline flow resistance of the air compressor and the working life of the assembly are monitored in real time, and the estimated results of the relevant information are reported in real time. Through self-checking and self-reporting of the health status of the air compressor, the after-sales end can intervene in targeted maintenance work in advance, thereby improving the service life of the whole machine, reducing the sudden failure of the air compressor, and ensuring the safe operation of the vehicle. Compared with the traditional alarm or shutdown protection strategy with upper limit, the present application focuses more on real-time state detection of the air compressor. By early detection and early intervention, the failure of the air compressor and the safety risk of the whole vehicle operation are reduced as much as possible.

[0008] In general, as the mutual wear and tear of the internal rotating parts of the air compressor intensifies, the internal rotating resistance increases. That is, at the same speed, the starting power will increase relatively. Similarly, when the motor speed of the air compressor reaches the rated working speed, the air compressor enters the charging working stage. If the mutual wear and tear of the internal rotating parts of the air compressor intensifies or the intake and exhaust are blocked, especially when the filter element accumulates too much impurity to cause the intake resistance to rise, the charging power will increase under the same outlet pressure condition. In addition, as the working time of the air compressor increases, its specific power will slowly increase, which is manifested by the increase in the energy required for the gas in the air tank to rise from a certain specific pressure to another specific pressure, i.e., the increase in the charging energy consumption.

[0009] One preferred scheme is that the working control process of the air compressor comprises the following steps:

[0010] Step S1, when the air pressure of the air tank is less than or equal to 0.65 MPa, the air compressor is enabled to work and starts charging; when the air pressure of the air tank is greater than 0.65 MPa, the air compressor working enable is closed, i.e., charging is stopped;

[0011] Step S2, three self-checking procedures are performed, including air compressor starting process test, air compressor charging process test, and air compressor charging energy consumption test;

[0012] Step S3, it is judged whether the exhaust signal of the dryer is received within 4 minutes; when the exhaust signal of the dryer is received, a delay of 10 seconds is performed, and then the air compressor working enable is closed, i.e., charging is stopped; when the exhaust signal of the dryer is not received, the dryer has a signal fault; return to step S1 for repeated operation.

[0013] One preferred scheme is that the air compressor starting process test comprises the following steps:

[0014] Step A1, first need to get the calibration test setting value of the starting process by calibration test, etc. Specifically, calibration test needs to be carried out on a sample vehicle to confirm that the air compressor inlet and outlet pipeline is smooth and there is no abnormal obstruction, and the cumulative working time of the air compressor does not exceed 30 minutes and there is no abnormality, and the air compressor enters the state of waiting to start;

[0015] Step A2, record the controller bus input power Q1, Q2 and Q3 of the air compressor motor speed at 300rpm, 600rpm and 900rpm respectively at a certain rated speed of 1500rpm. The above speed value is generally applicable to the current oil-free piston air compressor, and the rated speed is generally set to 1500rpm;

[0016] Calculate the calibration test setting value of the starting process:

[0017]

[0018] Wherein, PQ is the arithmetic mean of the controller bus input power of the air compressor at 300rpm, 600rpm and 900rpm respectively during calibration test;

[0019] S1 is the calibration test setting value of the starting process;

[0020] KQ is an empirical coefficient, which is calculated by inversely calculating the bus input power when the air compressor pump head is seriously worn and the rotation assistance is increased. Generally, the value is greater than 1;

[0021] Step A3, when the air pressure of the air cylinder is lower than 0.65MPa, the vehicle controller sends a work enable signal to the air compressor controller; the air compressor starts to work, and at the same time the vehicle controller runs the self-checking program of the air compressor starting process test. The vehicle controller reads the related bus input power through the communication line between the vehicle controller and the air compressor controller, and obtains QC1, QC2 and QC3 through difference operation respectively, and calculates the average difference QC;

[0022] Step A4, compare the average difference QC with the standard setting value of the starting process. If QC≥S1,

[0023] The vehicle controller sends a related signal to the instrument, and the instrument reports the related text of "serious wear" on the main page. The driver informs the maintenance personnel in time, and the maintenance personnel can carry out troubleshooting and fault clearing work according to the related maintenance manual. At the same time, the vehicle controller calculates the wear degree value QB and sends it to the instrument, and the instrument displays the wear degree value on the related subpage;

[0024] Step A4, if QC < S1, the driver or maintenance personnel assesses the current wear and tear of the air compressor pump head by checking the wear degree value, and determines whether to carry out appropriate maintenance work according to the relevant guidance documents to prolong the service life of the air compressor pump head.

[0025] One preferred solution is that the air compressor inflation process test comprises the following steps:

[0026] Step B1, first, the calibration test setting value of the starting process needs to be obtained through calibration test, etc. Specifically, calibration test needs to be carried out on a sample vehicle to confirm that the air compressor inlet and outlet pipeline is smooth and has no abnormal blockage, and that the cumulative working time of the air compressor does not exceed 30 minutes and has no abnormality, and the air compressor enters the state of waiting to start;

[0027] Step B2, after waiting for the motor speed of the air compressor with a rated speed of 1500 rpm to reach 1500 rpm, record the bus input power D1, D2, D3 of the air cylinder at 0.7 MPa, 0.8 MPa, 0.9 MPa respectively;

[0028] Calculate the calibration test setting value of the starting process:

[0029]

[0030] Wherein, PD is the arithmetic mean of the bus input power of the air compressor controller at 0.7 MPa, 0.8 MPa, 0.9 MPa respectively when the calibration test is carried out; S2 is the calibration test setting value of the inflation process; KD is an empirical coefficient, which is generally greater than 1, and is specifically obtained by comprehensively back calculating the bus current of the air compressor when the filter is severely blocked and the pump head is severely worn, resulting in increased rotating assistance;

[0031] Step B3, the motor speed of the air compressor reaches 1500 rpm to complete the starting process test, when the air cylinder pressure reaches 0.7 MPa, the vehicle control unit runs the self-checking program of the air compressor inflation process test, the vehicle control unit reads the relevant bus input power through the communication CAN line between the air compressor controller and the vehicle control unit, and obtains DC1, DC2, DC3 respectively through difference operation, and calculates the average difference DC.

[0032] Step B4, compare the average difference DC with the standard setting value of the starting process,

[0033] If DC≥S2, the vehicle controller sends a signal to the instrument, which reports the text "severe wear or severe intake and exhaust blockage" on the main page. The driver or maintenance personnel first checks whether the air compressor intake filter is severely blocked. If not, the relevant maintenance manual is used to troubleshoot and remove the fault. At the same time, the vehicle controller calculates the wear degree value QB and sends it to the instrument, which displays the wear degree value on the relevant subpage.

[0034] Step B5, if DC<S2, the driver or maintenance personnel assesses the current air compressor intake and exhaust flow resistance by checking the blockage degree value, and determines whether to carry out appropriate maintenance according to the relevant guidance documents to prolong the service life of the air compressor.

[0035] One preferred embodiment is that the air compressor pumping energy consumption test comprises the following steps:

[0036] Step C1, first, the pumping energy consumption setting value is obtained through comprehensive matching calculation and calibration test. The matching calculation calculates the energy consumed by the air compressor to pump the air cylinder pressure from 0.7MPa to 0.9MPa:

[0037]

[0038] Where t1 is the time required to pump the air cylinder pressure from 0MPa to 0.9MPa;

[0039] CR is the volume of the air cylinder and related air pipeline;

[0040] PF1 is the absolute pressure when the relative pressure of the gas inside the air cylinder is 0.9MPa;

[0041] Ts is the ambient absolute temperature;

[0042] Ps is the absolute pressure of the intake;

[0043] Qs is the average exhaust volume of the air compressor;

[0044] Tf is the final absolute temperature of the gas inside the air cylinder;

[0045] t2 is the time required to pump the air cylinder pressure from 0MPa to 0.7MPa;

[0046] PF2 is the absolute pressure when the relative pressure of the gas inside the air cylinder is 0.7MPa;

[0047] t3 is the time required to pump the air cylinder pressure from 0.7MPa to 0.9MPa;

[0048] W1 is the energy consumed by the air compressor to pressurize the air tank from 0.7 MPa to 0.9 MPa calculated by matching calculation method;

[0049] PE is the rated power of the air compressor motor;

[0050] Step C2, obtain the energy value consumed by the air compressor to pressurize the air tank from 0.7 MPa to 0.9 MPa by calibration test method, specifically, perform calibration test on the sample vehicle, confirm that the air compressor inlet and outlet pipeline is smooth without abnormal blockage, confirm that the cumulative working time of the air compressor does not exceed 30 minutes and is normal, start the air compressor normally, wait for the motor speed of the air compressor to reach 1500 rpm, and then wait for the air tank pressure value to reach 0.7 MPa, and then every 500 ms, obtain the input power of the bus before the air tank pressure reaches 0.9 MPa;

[0051] Step C3, calculate the energy consumed by the air compressor to pressurize the air tank from 0.7 MPa to 0.9 MPa by calibration test method:

[0052]

[0053] W2 is the energy consumed by the air compressor to pressurize the air tank from 0.7 MPa to 0.9 MPa calculated by calibration test method;

[0054] The time interval is 500 ms;

[0055]

[0056] S3 is the setting value of the energy consumption for pumping obtained by comprehensive matching calculation and calibration test method;

[0057] K1 is the weight coefficient of the energy consumed by the air compressor to pressurize the air tank from 0.7 MPa to 0.9 MPa calculated by matching calculation method;

[0058] K2 is the weight coefficient of the energy consumed by the air compressor to pressurize the air tank from 0.7 MPa to 0.9 MPa calculated by calibration test method;

[0059] K3 is an empirical coefficient, which is obtained by inverse calculation of reliability test data of the air compressor, and generally takes a value greater than 1;

[0060] Step C4, the air compressor motor speed reaches 1500 rpm when the starting process test is completed, when the air cylinder pressure reaches 0.7 MPa, the vehicle controller runs the air compressor test process test self-check program, the vehicle controller through the communication line between the air compressor controller, with the communication cycle 500 ms interval to obtain the bus current Ii and bus voltage Ui, and through the operation of the input power Pi;

[0061] Step C5, until the air cylinder pressure reaches 0.9 MPa, stop getting bus input power Pi, and through the summation Pi to get the air compressor assembly from the pressure 0.7 MPa to 0.9 MPa consumed energy W;

[0062] Step C6, if W≥S3, the vehicle controller to the instrument related signal, the instrument on the main page to report "air pump work abnormal, timely check" related text, at this time the driving personnel timely notify the maintenance personnel to the air compressor troubleshooting and fault clearing work, at the same time, the vehicle controller calculates the air compression performance attenuation degree value WB, and sends to the instrument, the instrument on the relevant page to display the wear degree value;

[0063] Step C7, if W<S3, the driver or maintenance personnel can evaluate the current air compressor performance whether to meet the normal operation of the vehicle requirements by checking the air compression performance attenuation degree value, and according to the relevant guidance documents to determine whether to carry out appropriate maintenance work, in order to prolong the service life of the air compressor. BRIEF DESCRIPTION OF DRAWINGS

[0064] Figure 1 is the connection diagram of the hardware related to the present application;

[0065] Figure 2 is the connection diagram of the hardware related to the present application;

[0066] Figure 3 is the working control flow chart of the present application;

[0067] Figure 4 is the logic diagram of the air compressor starting process test;

[0068] Figure 5 is the logic diagram of the air compressor test process test;

[0069] Figure 6 is the logic diagram of the air compressor test process test;

[0070] Figure 7 is the connection diagram of the air compressor;

[0071] Figure 8This is a plan view of the gas storage tank;

[0072] Figure 9 This is a plan view of the dryer;

[0073] Figure 10 This is a plan view of the filter;

[0074] Figure 11 This is a plan view of the air compressor;

[0075] Figure 12 This is a plan view of the air compressor controller;

[0076] Figure 13 This is a plan view of the instrument.

[0077] Figure 14 This is a plan view of the vehicle controller. Detailed Implementation

[0078] like Figures 1 to 14 As shown, in this embodiment, the present invention includes an air compressor 1, an air tank 2, an air compressor controller 3, an instrument panel 4, and a vehicle controller 5. External air enters the air inlet of the air compressor 1 through a filter 6, and the air outlet of the air compressor 1 enters the air tank 2 through a dryer 7. The air compressor 1 is electrically connected to the air compressor controller 3, and the instrument panel 4, the air compressor controller 3, the dryer 7, and the air tank 2 are all electrically connected to the vehicle controller 5. When the air pressure in the air tank 2 is lower than a specified value, the vehicle controller 5 sends a work enable signal to the air compressor controller 3, and the air compressor 1 starts working. The vehicle controller 5 runs three self-test programs, including an air compressor start-up process test, an air compressor inflation process test, and an air compressor inflation energy consumption test.

[0079] like Figure 3 As shown, in this embodiment, the operation control process of the air compressor 1 includes the following steps:

[0080] Step S1: When the air pressure in the air storage tank 2 is less than or equal to 0.65 MPa, the air compressor 1 is enabled and starts pumping air; when the air pressure in the air storage tank 2 is greater than 0.65 MPa, the air compressor 1 is disabled, i.e., pumping air stops.

[0081] Step S2: Perform three self-test procedures: air compressor start-up process test, air compressor inflation process test, and air compressor inflation energy consumption test.

[0082] Step S3, judge whether the exhaust signal of the dryer 7 is received within 4 minutes; when the exhaust signal of the dryer 7 is received, delay for 10 seconds, and then turn off the air compressor 1 work enable, that is, stop pumping; when the exhaust signal of the dryer 7 is not received, the dryer 7 has a signal fault; return to step S1 for repeated operation.

[0083] As shown in the embodiment, the air compressor starting process test includes the following steps: Figure 4

[0084] Step A1, first, the calibration test setting value of the starting process needs to be obtained through calibration test, etc. Specifically, calibration test needs to be performed on a sample vehicle to confirm that the air inlet and outlet pipeline of the air compressor 1 is smooth and has no abnormal blockage, to confirm that the cumulative working time of the air compressor 1 does not exceed 30 minutes and has no abnormality, and to confirm that the air compressor 1 enters a state ready to start;

[0085] Step A2, record the controller end bus input power Q1, Q2 and Q3 of the air compressor 1 motor speed at 300 rpm, 600 rpm and 900 rpm respectively at a certain rated speed of 1500 rpm. The above speed values are generally applicable to the current oil-free piston air compressor 1, and the rated speed is generally set to 1500 rpm;

[0086] Calculate the calibration test setting value of the starting process:

[0087]

[0088] Wherein, PQ is the arithmetic mean of the controller end bus input power of the air compressor 1 at 300 rpm, 600 rpm and 900 rpm during calibration test;

[0089] S1 is the calibration test setting value of the starting process;

[0090] KQ is an empirical coefficient, which is obtained by inversely calculating the bus input power when the pump head of the air compressor 1 is seriously worn and the rotation assistance is increased. Generally, the value is greater than 1;

[0091] Step A3, when the air pressure of the air tank 2 is lower than 0.65 MPa, the whole vehicle controller 5 sends a work enable signal to the air compressor controller 3; the air compressor 1 starts to work, and at the same time, the whole vehicle controller 5 runs the self-checking program of the air compressor starting process test, and reads the related bus input power through the communication line between the whole vehicle controller 5 and the air compressor controller 3, and obtains QC1, QC2 and QC3 through difference operation respectively, and calculates the average difference QC.

[0092] ​Step A4, compare the average difference value QC with the standard setting value of the starting process. If QC≥S1,

[0093] The vehicle controller 5 sends a relevant signal to the instrument 4, which reports the relevant text "severe wear" on the main page. The driver notifies the maintenance personnel in a timely manner, who can carry out troubleshooting and fault clearing work according to the relevant maintenance manual. At the same time, the vehicle controller 5 calculates the wear degree value QB and sends it to the instrument 4, which displays the wear degree value on the relevant subpage.

[0094] Step A4, if QC<S1, the driver or maintenance personnel assesses the current wear condition inside the pump head of the air compressor 1 by checking the wear degree value, and determines whether to carry out appropriate maintenance work according to the relevant guidance documents to prolong the service life of the pump head of the air compressor 1.

[0095] As shown in the embodiment, the air compressor pumping process test includes the following steps: Figure 5

[0096] Step B1, first, the calibration test setting value of the starting process needs to be obtained through calibration test, etc. Specifically, calibration test needs to be performed on the sample vehicle to confirm that the air inlet and outlet pipelines of the air compressor 1 are smooth and free of abnormal blockage, that the cumulative working time of the air compressor 1 does not exceed 30 minutes and is free of abnormalities, and that the air compressor 1 enters a state ready for starting;

[0097] Step B2, after waiting for the motor speed of the air compressor 1 with a rated speed of 1500 rpm to reach 1500 rpm, record the bus input power D1, D2, D3 of the air cylinder 2 at air pressures of 0.7 MPa, 0.8 MPa, and 0.9 MPa, respectively;

[0098] Calculate the calibration test setting value of the starting process:

[0099]

[0100] wherein PD is the arithmetic mean of the bus input power of the air compressor controller 3 at air pressures of 0.7 MPa, 0.8 MPa, and 0.9 MPa of the air cylinder 2 during calibration test; S2 is the calibration test setting value of the pumping process; KD is an empirical coefficient, which is generally greater than 1 and is calculated by comprehensively back-calculating the bus current of the air compressor 1 when the pre-filter 6 is severely clogged and the pump head is severely worn, resulting in increased rotational assistance;

[0101] ​Step B3: When the motor speed of the air compressor 1 reaches 1500 rpm, the start-up process test is completed. When the air pressure of the air tank 2 reaches 0.7 MPa, the vehicle controller 5 runs the self-test program for the air compressor inflation process test. The vehicle controller 5 reads the relevant bus input power through the communication CAN line between the air compressor controller 3 and the air compressor controller 3, and obtains DC1, DC2, and DC3 respectively through difference calculation, and calculates the average difference DC.

[0102] Step B4: Compare the average difference DC with the standard setting value during the startup process.

[0103] If DC≥S2, the vehicle controller 5 sends a relevant signal to the instrument 4. The instrument 4 displays the text "severe wear or severe intake / exhaust blockage" on its main page. The driver or maintenance personnel first check whether the air compressor 1 intake filter is severely blocked. If not, they then carry out troubleshooting and fault clearing work according to the relevant maintenance manual. At the same time, the vehicle controller 5 calculates the wear degree value QB and sends it to the instrument 4. The instrument 4 displays the wear degree value on the relevant subpage.

[0104] Step B5: If DC < S2, the driver or maintenance personnel shall assess the current intake and exhaust flow resistance of the air compressor 1 by checking the blockage level value, and determine whether to carry out appropriate maintenance work according to relevant guidance documents in order to extend the service life of the air compressor 1.

[0105] like Figure 6 As shown, in this embodiment, the air compressor energy consumption test includes the following steps:

[0106] Step C1: First, the energy consumption setting value for air compressor 1 needs to be obtained through comprehensive matching calculation and calibration test. The matching calculation method calculates the energy consumed by the air compressor 1 to increase the air pressure of the air tank 2 from 0.7MPa to 0.9MPa:

[0107]

[0108] Where t1 is the time required for the air pressure in the air storage cylinder 2 to increase from 0 MPa to 0.9 MPa;

[0109] CR is the volume of the gas storage tank 2 and related gas pipelines;

[0110] PF1 is the absolute pressure when the relative pressure of the gas inside the gas storage cylinder 2 is 0.9 MPa;

[0111] Ts represents the absolute ambient temperature;

[0112] Ps is the absolute pressure of the intake air;

[0113] Qs is the average exhaust volume of the air compressor 1;

[0114] Tf is the final absolute temperature of the gas inside the air cylinder 2;

[0115] t2 is the time required for the air pressure of the air cylinder 2 to rise from 0 MPa to 0.7 MPa;

[0116] PF2 is the absolute pressure of the air inside the air cylinder 2 when the relative pressure is 0.7 MPa;

[0117] t3 is the time required for the air pressure of the air cylinder 2 to rise from 0.7 MPa to 0.9 MPa;

[0118] W1 is the energy consumed by the air compressor 1 to raise the air pressure of the air cylinder 2 from 0.7 MPa to 0.9 MPa, calculated by matching calculation;

[0119] PE is the rated power of the motor of the air compressor 1;

[0120] Step C2, the value of the energy consumed by the air compressor 1 to raise the air pressure of the air cylinder 2 from 0.7 MPa to 0.9 MPa is obtained by calibration test, which specifically needs to be calibrated on a sample vehicle, to confirm that the air inlet and outlet pipelines of the air compressor 1 are smooth and have no abnormal blockage, to confirm that the cumulative working time of the air compressor 1 does not exceed 30 minutes and has no abnormalities, to normally start the air compressor 1, to wait for the motor speed of the air compressor 1 to reach 1500 rpm, and to wait for the air pressure value of the air cylinder 2 to reach 0.7 MPa to start obtaining the input power of the bus before the air pressure of the air cylinder 2 reaches 0.9 MPa every 500 ms;

[0121] Step C3, the energy consumed by the air compressor 1 to raise the air pressure of the air cylinder 2 from 0.7 MPa to 0.9 MPa is calculated by calibration test:

[0122]

[0123] wherein W2 is the energy consumed by the air compressor 1 to raise the air pressure of the air cylinder 2 from 0.7 MPa to 0.9 MPa, calculated by calibration test;

[0124] is the time interval 500 ms;

[0125]

[0126] wherein S3 is the setting value of the inflation energy consumption obtained by comprehensive matching calculation and calibration test;

[0127] K1 is the energy weight coefficient consumed by the air compressor 1 to pressurize the air cylinder 2 from 0.7 MPa to 0.9 MPa, which is calculated by matching calculation method;

[0128] K2 is the energy weight coefficient consumed by the air compressor 1 to pressurize the air cylinder 2 from 0.7 MPa to 0.9 MPa, which is calculated by calibration test method;

[0129] K3 is an empirical coefficient, which is obtained by inversely calculating the reliability test data of the air compressor 1, and is generally greater than 1;

[0130] Step C4, the air compressor 1 motor speed reaches 1500 rpm to complete the start-up test, when the air cylinder 2 pressure reaches 0.7 MPa, the vehicle controller 5 runs the self-checking program of the air compressor pressurization test, the vehicle controller 5 obtains the bus current Ii and bus voltage Ui through the communication line between the air compressor controller 3 at an interval of a communication period of 500 ms, and obtains the input power Pi through operation;

[0131] Step C5, until the air cylinder 2 pressure reaches 0.9 MPa, stop obtaining the bus input power Pi, and obtain the energy W consumed by the air compressor 1 assembly from the air pressure of 0.7 MPa to 0.9 MPa by summation Pi;

[0132] Step C6, if W≥S3, the vehicle controller 5 sends a related signal to the instrument 4, and the instrument 4 reports the related text of "air pump working abnormally, check in time" on the main page, at this time, the driving personnel timely informs the maintenance personnel to carry out fault elimination and fault removal work on the air compressor 1, and the vehicle controller 5 calculates the pressurization performance attenuation degree value WB and sends it to the instrument 4, and the instrument 4 displays the wear degree value on the related subpage;

[0133] Step C7, if W<S3, the driver or the maintenance personnel can evaluate whether the working performance of the air compressor 1 meets the normal operation demand of the vehicle by checking the pressurization performance attenuation degree value, and judge whether to carry out appropriate maintenance work according to the related guidance document, so as to prolong the working life of the air compressor 1.

[0134] Although the embodiments of the present application are described in actual schemes, but do not constitute a limitation on the meaning of the present application, and it is obvious for those skilled in the art to modify the embodiments thereof according to the present specification and combine them with other schemes.

Claims

1. A self-testing method for the working performance of an air compressor, characterized in that: The system includes an air compressor (1), an air tank (2), an air compressor controller (3), an instrument (4), and a vehicle controller (5). External air is introduced into the air inlet of the air compressor (1) through a filter (6), and the air outlet of the air compressor (1) is introduced into the air tank (2) through a dryer (7). The air compressor (1) is electrically connected to the air compressor controller (3), and the instrument (4), the air compressor controller (3), the dryer (7), and the air tank (2) are all electrically connected to the vehicle controller (5). The working control process of the air compressor (1) includes the following steps: Step S1: When the air pressure in the air storage tank (2) is less than or equal to 0.65 MPa, turn on the air compressor (1) to start pumping air; when the air pressure in the air storage tank (2) is greater than 0.65 MPa, turn off the air compressor (1) to stop pumping air. Step S2: Perform three self-test procedures: air compressor start-up process test, air compressor inflation process test, and air compressor inflation energy consumption test. Step S3: Determine whether an exhaust signal from the dryer (7) is received within 4 minutes; if an exhaust signal from the dryer (7) is received, delay for 10 seconds, and then turn off the working enable of the air compressor (1), that is, stop pumping air; if no exhaust signal from the dryer (7) is received, the dryer (7) has a signal failure; return to step S1 to repeat the operation. The air compressor startup process test includes the following steps: Step A1: First, the calibration test setting value of the startup process needs to be obtained through calibration test. Specifically, calibration test needs to be carried out on the prototype vehicle to confirm that the air compressor (1) has smooth airflow and no abnormal blockage in the air inlet and outlet pipes, and to confirm that the cumulative working time of the air compressor (1) does not exceed 30 minutes and there are no abnormalities. The air compressor (1) enters the standby state. Step A2: Record the controller bus input power Q1, Q2 and Q3 of the motor speed of the air compressor (1) with a rated speed of 1500 rpm at R1, R2 and R3 respectively. R1, R2 and R3 are 300 rpm, 600 rpm and 900 rpm respectively. The above speed values ​​are generally applicable to the current oil-free piston air compressor (1), and its rated speed is generally set to 1500 rpm. Calculate the calibration test settings for the startup process: Wherein, PQ is the arithmetic mean of the controller bus input power of the air compressor (1) at 300rpm, 600rpm and 900rpm respectively during the calibration test; S1 is the calibration test setting value for the startup process; KQ is an empirical coefficient, specifically calculated by back-calculating the bus input power when the air compressor (1) pump head is severely worn, resulting in increased rotational assistance. It is generally taken as a value greater than 1. Step A3: When the air pressure in the air tank (2) is lower than 0.65MPa, the vehicle controller (5) sends a work enable signal to the air compressor controller (3); the air compressor (1) starts to work, and at the same time, the vehicle controller (5) runs the self-test program for the air compressor start-up process test. The vehicle controller (5) reads the bus input power of the air compressor (1) motor speed at R1±20rpm, R2±20rpm, and R3±20rpm respectively through the communication line between the vehicle controller (5) and the air compressor controller (3), and subtracts Q1, Q2, and Q3 respectively to obtain QC1, QC2, and QC3, and calculates the average difference QC = (QC1 + QC2 + QC3) / 3. Step A4: Compare the average difference QC with the standard setting value of the startup process. If QC ≥ S1, The vehicle controller (5) sends relevant signals to the instrument (4), and the instrument (4) displays the text "severe wear" on the main page; the driver promptly notifies the maintenance personnel, who can carry out troubleshooting and fault clearing work according to the relevant maintenance manual. At the same time, the vehicle controller (5) calculates the wear degree value QB and sends it to the instrument (4), and the instrument (4) displays the wear degree value on the relevant subpage. Step A4: If QC < S1, the driver or maintenance personnel shall assess the current wear condition of the air compressor (1) pump head by checking the wear value, and determine whether to carry out appropriate maintenance work according to the relevant guidance documents in order to extend the working life of the air compressor (1) pump head.

2. The self-testing method for the working performance of an air compressor according to claim 1, characterized in that: The air compressor inflation process test includes the following steps: Step B1: First, the calibration test setting value of the start-up process needs to be obtained through calibration test. Specifically, calibration test needs to be carried out on the prototype vehicle to confirm that the air compressor (1) has smooth airflow and no abnormal blockage in the air inlet and outlet pipes, and to confirm that the cumulative working time of the air compressor (1) does not exceed 30 minutes and there are no abnormalities. The air compressor (1) enters the standby state. Step B2: After the motor speed of the air compressor (1) with a rated speed of 1500 rpm reaches 1500 rpm, record the bus input power D1, D2, and D3 of the air storage tank (2) at air pressures of 0.7 MPa, 0.8 MPa, and 0.9 MPa, respectively. Calculate the calibration test settings for the startup process: Wherein, PD is the arithmetic mean of the bus input power of the air compressor controller (3) when the air pressure of the air tank (2) is 0.7MPa, 0.8MPa and 0.9MPa respectively during the calibration test; S2 is the calibration test setting value of the air pumping process; KD is an empirical coefficient, which is specifically calculated by back-calculating the bus current of the air compressor (1) when the pre-filter (6) is severely blocked and the pump head is severely worn, resulting in increased rotational assistance. It is generally taken as greater than 1. Step B3: When the motor speed of the air compressor (1) reaches 1500 rpm, the start-up process test is completed. When the air pressure of the air tank (2) reaches 0.7 MPa, the vehicle controller (5) runs the self-test program of the air compressor inflation process test. The vehicle controller (5) reads the bus input power of the air tank (2) at air pressures of 0.7±0.01 MPa, 0.8±0.01 MPa, and 0.9±0.01 MPa respectively through the communication CAN line between the vehicle controller (3) and the air compressor controller (3), and subtracts D1, D2, and D3 respectively to obtain DC1, DC2, and DC3, and calculates the average difference DC = (DC1 + DC2 + DC3) / 3. Step B4: Compare the average difference DC with the standard setting value of the start-up process. If DC ≥ S2, the vehicle controller (5) sends a relevant signal to the instrument (4). The instrument (4) displays the text "severe wear or severe blockage of intake and exhaust" on the main page. The driver or maintenance personnel first check whether the intake filter of the air compressor (1) is severely blocked. If not, they carry out troubleshooting and fault clearing work according to the relevant maintenance manual. At the same time, the vehicle controller (5) calculates the wear degree value QB and sends it to the instrument (4). The instrument (4) displays the wear degree value on the relevant subpage. Step B5: If DC < S2, the driver or maintenance personnel shall assess the current intake and exhaust flow resistance of the air compressor (1) by checking the blockage level value, and determine whether to carry out appropriate maintenance work in accordance with relevant guidance documents to extend the working life of the air compressor (1).

3. The self-testing method for the working performance of an air compressor according to claim 1, characterized in that: The air compressor energy consumption test includes the following steps: Step C1: First, the setting value of the air compressor energy consumption needs to be obtained through comprehensive matching calculation and calibration test. The matching calculation method calculates the energy consumed by the air compressor (1) to pump the air pressure of the air tank (2) from 0.7MPa to 0.9MPa: Where t1 is the time required for the gas pressure in the gas storage cylinder (2) to rise from 0 MPa to 0.9 MPa; CR is the volume of the gas storage cylinder (2) and related gas pipelines; PF1 is the absolute pressure when the relative pressure of the gas inside the gas storage cylinder (2) is 0.9 MPa; Ts represents the absolute ambient temperature; Ps is the absolute pressure of the intake air; Qs is the average discharge capacity of the air compressor (1); Tf is the final absolute temperature of the gas inside the gas storage cylinder (2); t2 is the time required for the gas pressure in the gas storage cylinder (2) to increase from 0 MPa to 0.7 MPa; PF2 is the absolute pressure when the relative pressure of the gas inside the gas storage cylinder (2) is 0.7 MPa; t3 is the time required for the gas pressure in the gas storage cylinder (2) to increase from 0.7MPa to 0.9MPa; W1 is the energy consumed by the air compressor (1) to increase the air pressure in the air storage tank (2) from 0.7MPa to 0.9MPa by the matching calculation method; PE is the rated power of the motor of the air compressor (1); Step C2: Obtain the energy consumed by the air compressor (1) to increase the air pressure of the air tank (2) from 0.7MPa to 0.9MPa through calibration test. Specifically, calibration test needs to be performed on the prototype vehicle to confirm that the air inlet and outlet pipes of the air compressor (1) are unobstructed and there are no abnormal blockages. Confirm that the cumulative working time of the air compressor (1) does not exceed 30 minutes and there are no abnormalities. Start the air compressor (1) normally. After the motor speed of the air compressor (1) reaches 1500rpm, wait for the air pressure of the air tank (2) to reach 0.7MPa and start to obtain the bus input power of the air tank (2) before the air pressure reaches 0.9MPa every 500ms. Step C3: Calculate the energy consumed by the air compressor (1) to increase the air pressure in the air tank (2) from 0.7 MPa to 0.9 MPa using the calibration test method. Wherein, W2 is the energy consumed by the air compressor (1) to pump the air pressure of the air storage tank (2) from 0.7MPa to 0.9MPa using the calibration test method; The time interval is 500ms; Among them, S3 is the setting value of inflation energy consumption obtained by comprehensive matching calculation and calibration test; K1 is the weighting coefficient for calculating the energy consumed by the air compressor (1) to increase the air pressure of the air storage tank (2) from 0.7MPa to 0.9MPa using the matching calculation method; K2 is the weighting coefficient for calculating the energy consumed by the air compressor (1) to increase the air pressure of the air tank (2) from 0.7MPa to 0.9MPa using the calibration test method; K3 is an empirical coefficient, specifically calculated by back-calculating the reliability test data of the air compressor (1), and is generally greater than 1. Step C4: When the motor speed of the air compressor (1) reaches 1500 rpm, the start-up process test is completed. When the air pressure of the air tank (2) reaches 0.7 MPa, the vehicle controller (5) runs the self-test program of the air compressor inflation process test. The vehicle controller (5) obtains the bus current Ii and bus voltage Ui at a communication cycle interval of 500 ms through the communication line between the vehicle controller (3) and the air compressor controller (3), and obtains the input power Pi through calculation. Step C5: When the air pressure in the air storage tank (2) reaches 0.9MPa, stop acquiring the bus input power Pi, and obtain the energy W consumed by the air compressor (1) assembly from 0.7MPa to 0.9MPa by summing Pi; Step C6: If W≥S3, the vehicle controller (5) sends a relevant signal to the instrument (4), and the instrument (4) reports the relevant text "Air pump is malfunctioning, check it in time" on the main page. At this time, the driver promptly notifies the maintenance personnel to troubleshoot and clear the fault of the air compressor (1). Meanwhile, the vehicle controller (5) calculates the inflation performance attenuation value WB and sends it to the instrument (4). The instrument (4) displays the wear value on the relevant subpage. Step C7: If W < S3, the driver or maintenance personnel can assess whether the current working performance of the air compressor (1) meets the normal operating requirements of the vehicle by checking the inflation performance attenuation value, and determine whether to carry out appropriate maintenance work according to relevant guidance documents in order to extend the working life of the air compressor (1).

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