Intelligent valve positioner and IP unit fault diagnosis method

Abstract

The invention relates to the field of industrial control, in particular to an intelligent valve positioner and IP unit fault diagnosis method which comprises the steps that the position of a regulating valve is collected in real time; according to an expected regulating valve position corresponding to the valve control command and the position of the regulating valve, whether the IP unit works abnormally or not is diagnosed; and under the condition of abnormal work, a diagnosis mode of the intelligent valve positioner is started, the driving voltage and the output pressure of the IP unit are collected, and the fault reason of the IP unit is diagnosed according to the driving voltage and the output pressure. According to the method, the number of use times, the driving voltage and the performance of the IP unit are monitored and analyzed in real time, so that possible faults can be found and early warned in time. Compared with manual inspection, the efficiency and accuracy of fault diagnosis can be greatly improved. Besides, more effective maintenance reference can be provided for maintenance personnel through accurate identification of fault causes, and reduction of maintenance time and cost is facilitated.

Description

Technical Field

[0001] The present invention relates to the field of industrial control, and in particular to a method for diagnosing faults of an intelligent valve positioner and an IP unit. Background Art

[0002] Intelligent valve positioner is an important part of modern industrial control system. It receives control signals and accurately adjusts the valve opening to control the flow of fluid. In intelligent valve positioner, IP unit (electrical conversion unit, Current to Pressure) plays a vital role. Its main task is to convert electrical signals into air pressure signals to drive valve actuator and control the switch position of valve. Figure 1 As shown, the intelligent valve positioner includes an IP unit (i.e. Figure 1 I / P unit in the control unit (i.e. Figure 1 The IP unit is connected to the actuator of the regulating valve. The control unit sends a valve control command to the IP unit. The IP unit controls the movement of the valve stem of the regulating valve through the actuator according to the command to change the position of the regulating valve. However, the IP unit may fail during use, resulting in the inability to accurately control the valve or even causing the system to shut down.

[0003] Currently, fault diagnosis of IP units mainly relies on manual inspection, which is not only inefficient but may not be able to detect and repair faults in a timely manner. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a method, system and device for diagnosing IP unit failure.

[0005] The first aspect of the present invention discloses an intelligent valve positioner, comprising a control unit, an IP unit, a position acquisition unit and two pressure acquisition units:

[0006] The IP unit is externally connected to a regulating valve, and is used to perform intake, exhaust, or holding actions according to the valve control command of the control unit to adjust the position of the regulating valve;

[0007] The two pressure collection units, one of which is arranged at the air inlet of the IP unit, for measuring the air source pressure of the air inlet of the IP unit; and one of which is arranged at the air outlet of the IP unit, for measuring the output pressure of the air outlet of the IP unit;

[0008] The position acquisition unit is used to measure the position of the regulating valve;

[0009] The control unit is used to generate the valve control command according to the input control command and the position of the regulating valve;

[0010] The control unit is also used to diagnose whether the IP unit is working abnormally according to the valve control instruction and the position of the regulating valve, and when working abnormally, start the diagnosis mode to diagnose the fault of the IP unit according to the driving voltage of the IP unit and the output pressure.

[0011] Furthermore, the control unit is also used to count the number of times the electric valve of the IP unit is used, and to diagnose whether the gas source pressure and service life of the IP unit are abnormal based on the gas source pressure and the number of times it is used.

[0012] Furthermore, the control unit is also used to generate different diagnostic voltages to the IP unit in the diagnostic mode, collect the corresponding driving voltage of the IP unit and the output pressure, and diagnose the fault of the IP unit.

[0013] A second aspect of the present invention discloses a method for diagnosing an IP unit fault, the method being applied to any one of the intelligent valve positioners disclosed in the first aspect of the present invention, the method comprising:

[0014] Collect the position of the regulating valve in real time;

[0015] diagnose whether the IP unit is working abnormally according to the expected regulating valve position corresponding to the valve control command and the position of the regulating valve;

[0016] In the case of abnormal operation, the diagnostic mode of the intelligent valve positioner is turned on to collect the driving voltage and output pressure of the IP unit, and the cause of the failure of the IP unit is diagnosed accordingly.

[0017] Furthermore, the diagnostic method also includes:

[0018] Collecting the gas source pressure of the intelligent valve positioner in real time;

[0019] The gas source pressure collected in real time is detected according to a preset gas source pressure range:

[0020] When the gas source pressure exceeds the gas source pressure range, an abnormal gas source pressure fault occurs in the IP unit.

[0021] Furthermore, the diagnostic method also includes:

[0022] Real-time collection of the usage times of the electric valve of the IP unit;

[0023] The number of uses is tested according to the preset maximum safe number of valve operations:

[0024] When the number of uses exceeds the maximum safe number of valve operations, the IP unit has an electric valve aging fault.

[0025] Further, the step of diagnosing whether the IP unit is working abnormally according to the expected regulating valve position corresponding to the valve control command and the position of the regulating valve includes:

[0026] Compare the difference between the position of the regulating valve and the expected position of the regulating valve:

[0027] If the difference is greater than a preset difference threshold, the IP unit operates abnormally;

[0028] Otherwise, the IP unit works normally.

[0029] Further, the step of starting the diagnostic mode of the intelligent valve positioner, collecting the driving voltage and output pressure of the IP unit, and diagnosing the cause of the failure of the IP unit accordingly includes:

[0030] Turn on the diagnostic mode of the smart valve positioner.

[0031] generating a first diagnostic voltage and a second diagnostic voltage respectively, wherein the first diagnostic voltage is greater than the second diagnostic voltage;

[0032] collecting a first driving voltage of the IP unit corresponding to a first diagnostic voltage and a second driving voltage of the IP unit corresponding to a second diagnostic voltage;

[0033] The first driving voltage and the second driving voltage are judged according to the first diagnostic voltage and the second diagnostic voltage:

[0034] When the first driving voltage and / or the second driving voltage is abnormal, the fault cause of the IP unit is the abnormal driving voltage.

[0035] Furthermore, the step of collecting the driving voltage and output pressure of the IP unit and diagnosing the cause of the failure of the IP unit accordingly includes:

[0036] The IP unit is controlled to perform different actions through valve control commands, and the output pressure of the IP unit is collected. The difference in the output pressure when performing different actions is compared, and whether the IP unit has performance abnormalities is determined based on whether the difference is less than a preset pressure difference threshold.

[0037] Furthermore, the steps of controlling the IP unit to perform different actions through the valve control command, collecting the output pressure of the IP unit, comparing the difference of the output pressure when performing different actions, and judging whether the IP unit has performance abnormality according to whether the difference is less than a preset pressure difference threshold include:

[0038] The IP unit is controlled to perform exhaust action through the valve control command, and after a first preset time, the output pressure is collected as the first output pressure;

[0039] The IP unit is controlled to perform the air intake action through the valve control command, and after the second preset time, the output pressure is collected as the second output pressure;

[0040] The IP unit is controlled to perform a holding action through a valve control command, and after a third preset time period, the output pressure is collected as a third output pressure;

[0041] Compare the first output pressure, the second output pressure, and the third output pressure with each other:

[0042] When there is a pressure difference greater than a preset pressure difference threshold, the IP unit has a performance abnormality.

[0043] The present invention provides a method for diagnosing IP unit faults. The method can timely discover and warn of possible faults by real-time monitoring and analysis of the number of times the IP unit is used, the driving voltage and the performance. Compared with manual inspection, the present invention can greatly improve the efficiency and accuracy of fault diagnosis. In addition, by accurately identifying the cause of the fault, a more effective maintenance reference can be provided for maintenance personnel, which helps to reduce maintenance time and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 It is a working principle diagram of the intelligent valve positioner disclosed in the background technology of the present invention;

[0046] Figure 2 is a structural diagram of an intelligent valve positioner disclosed in an embodiment of the present invention;

[0047] Figure 3 The present invention discloses a flow chart of a method for diagnosing an IP unit failure. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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.

[0049] The terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, device, or product end including a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units inherent to these processes, methods, products, or ends.

[0050] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0051] See also Figure 2 As shown, Figure 2 is a structural diagram of an intelligent valve positioner disclosed in an embodiment of the present invention. Figure 2 As shown, the intelligent valve positioner includes a control unit, an IP unit, a position acquisition unit and two pressure acquisition units:

[0052] The IP unit is externally connected to a regulating valve, and is used to perform intake, exhaust, or holding actions according to the valve control command of the control unit to adjust the position of the regulating valve;

[0053] The two pressure collection units, one of which is arranged at the air inlet of the IP unit, for measuring the air source pressure of the air inlet of the IP unit; and one of which is arranged at the air outlet of the IP unit, for measuring the output pressure of the air outlet of the IP unit;

[0054] The position acquisition unit is used to measure the position of the regulating valve;

[0055] The control unit is used to generate the valve control command according to the input control command and the position of the regulating valve;

[0056] The control unit is also used to diagnose whether the IP unit is working abnormally according to the valve control instruction and the position of the regulating valve, and when working abnormally, start the diagnosis mode to diagnose the fault of the IP unit according to the driving voltage of the IP unit and the output pressure.

[0057] Figure 2 The MCU (Microcontroller Unit) is the control unit, the I / P is the IP unit, the travel sensor is the position acquisition unit, and the pressure sensor is the pressure acquisition unit. The various units in the blue dotted box belong to the intelligent valve positioner, and the regulating valve is an external device of the intelligent valve positioner. In this embodiment, the intelligent valve positioner also includes a regulator for receiving external control operations, an analog-to-digital signal conversion unit (i.e., A / D), and a current feedback unit.

[0058] The working process of the intelligent valve positioner controlling the regulating valve is as follows: the regulator receives external operation as signal input and transmits it to the MCU, the MCU generates a valve control command based on the signal and transmits it to the I / P, and the I / P controls the position of the regulating valve based on the valve control command.

[0059] For the workflow of the intelligent valve positioner for diagnosing IP unit failure, please refer to the embodiment of the method for diagnosing IP unit failure below.

[0060] In an optional embodiment, the control unit is also used to count the number of times the electric valve of the IP unit is used, and to diagnose whether the gas source pressure and service life of the IP unit are abnormal based on the gas source pressure and the number of times used.

[0061] It can be seen that this optional embodiment can understand the actual use of the electric valve by counting and monitoring the number of times the electric valve is used, further predict and evaluate the life of the electric valve, and prevent the electric valve from being damaged due to excessive use. In addition, combined with real-time monitoring of the gas source pressure, abnormal gas source pressure can be discovered in time, which is helpful for preventing equipment failures caused by excessively high or low pressure and improving the reliability and stability of the entire system.

[0062] In an optional embodiment, the control unit is further used to generate different diagnostic voltages to the IP unit in a diagnostic mode, collect the corresponding driving voltage of the IP unit and the output pressure, and diagnose a fault of the IP unit.

[0063] It can be seen that by changing the driving voltage in the diagnostic mode, the working state of the IP unit under different voltages can be detected to more accurately determine whether it has a fault. In addition, by collecting and comparing the driving voltage and output pressure data under different diagnostic voltages, the performance of the IP unit can be more comprehensively analyzed and diagnosed, thereby helping users to quickly and accurately identify possible problems and perform repairs or replacements in a timely manner, thereby improving the operating efficiency and reliability of the equipment.

[0064] See also Figure 3 As shown, Figure 3 FIG. 1 is a flow chart of a method for diagnosing an IP unit failure disclosed in an embodiment of the present invention. Figure 3 As shown, the method for diagnosing the IP unit failure includes:

[0065] S101, collecting the position of the regulating valve in real time;

[0066] In this optional embodiment, the control unit Figure 2 The stroke sensor shown detects the position of the control valve.

[0067] S102, diagnosing whether the IP unit is working abnormally according to the expected regulating valve position corresponding to the valve control command and the position of the regulating valve;

[0068] In an optional embodiment, the step of diagnosing whether the IP unit is working abnormally according to the expected regulating valve position corresponding to the valve control command and the position of the regulating valve includes:

[0069] Compare the difference between the position of the regulating valve and the expected position of the regulating valve:

[0070] If the difference is greater than a preset difference threshold, the IP unit operates abnormally;

[0071] Otherwise, the IP unit works normally.

[0072] Under normal working conditions, the regulating valve should be able to complete the position adjustment within the set time. If the valve position is not adjusted in place within the set time, it is likely that there is a fault in the IP unit, causing the valve to fail to work properly. Therefore, by monitoring the adjustment status of the valve position, it is possible to effectively detect whether there is a fault in the IP unit.

[0073] In this optional embodiment, the control unit generates a valve control command based on the input signal, calculates the expected regulating valve position corresponding to the input signal, and then waits for a preset valve waiting time. The position of the regulating valve is collected in real time by the position acquisition unit, and is compared with the expected regulating valve position. If the difference between the two is greater than a preset difference threshold, it is determined that the IP unit is operating abnormally; otherwise, the IP unit is operating normally.

[0074] It can be seen that this optional embodiment can more accurately determine whether the IP unit is abnormal by setting the difference threshold, thereby improving the accuracy of fault detection. At the same time, this method can also tolerate valve position deviations within a small range, avoiding false alarms caused by small deviations and improving the stability of the system.

[0075] S103. In the case of abnormal operation, the diagnosis mode of the intelligent valve positioner is turned on to collect the driving voltage and output pressure of the IP unit, and diagnose the cause of the failure of the IP unit accordingly.

[0076] In an optional embodiment, the step of starting the diagnostic mode of the intelligent valve positioner, collecting the driving voltage and output pressure of the IP unit, and diagnosing the cause of the failure of the IP unit accordingly comprises:

[0077] Turn on the diagnostic mode of the smart valve positioner.

[0078] generating a first diagnostic voltage and a second diagnostic voltage respectively, wherein the first diagnostic voltage is greater than the second diagnostic voltage;

[0079] collecting a first driving voltage of the IP unit corresponding to a first diagnostic voltage and a second driving voltage of the IP unit corresponding to a second diagnostic voltage;

[0080] The first driving voltage and the second driving voltage are judged according to the first diagnostic voltage and the second diagnostic voltage:

[0081] When the first driving voltage and / or the second driving voltage is abnormal, the fault cause of the IP unit is the abnormal driving voltage.

[0082] In this optional embodiment, the MCU controls the driving voltage of the IP unit to be all high (first diagnostic voltage), then recycles the driving voltage and determines whether it is all high. Next, the MCU controls the driving voltage of the IP unit to be all low (second diagnostic voltage), then recycles the driving voltage and determines whether it is all low. If any of these two states is incorrect, it can be determined that there is an error in the driving voltage of the positioner mainboard.

[0083] It can be seen that this optional embodiment can more comprehensively and accurately determine the working state of the IP unit by detecting the driving voltage in the two extreme states of full high and full low. If the driving voltage is abnormal in any state, it means that there is an error in the driving voltage of the positioner mainboard. This method can improve the accuracy of fault diagnosis and make fault detection more accurate, thereby facilitating timely and accurate repair or replacement, and improving the operating efficiency and reliability of the equipment.

[0084] In an optional embodiment, the step of collecting the driving voltage and output pressure of the IP unit and diagnosing the cause of the failure of the IP unit accordingly comprises:

[0085] The IP unit is controlled to perform different actions through valve control commands, and the output pressure of the IP unit is collected. The difference in the output pressure when performing different actions is compared, and whether the IP unit has performance abnormalities is determined based on whether the difference is less than a preset pressure difference threshold.

[0086] In a further optional embodiment, the step of controlling the IP unit to perform different actions through the valve control command, collecting the output pressure of the IP unit, comparing the difference of the output pressure when performing different actions, and judging whether the IP unit has a performance abnormality according to whether the difference is less than a preset pressure difference threshold comprises:

[0087] The IP unit is controlled to perform exhaust action through the valve control command, and after a first preset time, the output pressure is collected as the first output pressure;

[0088] The IP unit is controlled to perform the air intake action through the valve control command, and after the second preset time, the output pressure is collected as the second output pressure;

[0089] The IP unit is controlled to perform a holding action through a valve control command, and after a third preset time period, the output pressure is collected as a third output pressure;

[0090] Compare the first output pressure, the second output pressure, and the third output pressure with each other:

[0091] When there is a pressure difference greater than a preset pressure difference threshold, the IP unit has a performance abnormality.

[0092] Under normal working conditions, the output pressure of the IP unit in the exhaust, intake and holding states should change significantly. If the output pressure does not change in these three states, it is likely that there is a fault in the IP unit, causing it to not work properly. Therefore, by monitoring the output pressure in different states, it is effective to detect whether the IP unit has a fault.

[0093] To illustrate this embodiment, first, the IP unit is set to the exhaust state and maintained for 50ms, and then the pressure acquisition processing module is called to collect the output pressure. Next, the IP unit is set to the intake state and maintained for 50ms, and the pressure acquisition processing module is called again to collect the output pressure. Finally, the IP unit is set to the hold state and maintained for 50ms, and the pressure acquisition processing module is called again to collect the output pressure. If the output pressure does not change in these three states, it can be determined that the IP unit is faulty.

[0094] It can be seen that this optional embodiment can more comprehensively and accurately determine the working state of the IP unit by detecting the output pressure of the IP unit in different states, thereby improving the accuracy of fault diagnosis. In addition, this method can also help users quickly and accurately find possible problems and perform repairs or replacements in a timely manner, thereby improving the operating efficiency and reliability of the equipment.

[0095] In an optional embodiment, the diagnostic method further comprises:

[0096] Collecting the gas source pressure of the intelligent valve positioner in real time;

[0097] The gas source pressure collected in real time is detected according to a preset gas source pressure range:

[0098] When the gas source pressure exceeds the gas source pressure range, an abnormal gas source pressure fault occurs in the IP unit.

[0099] The normal operation of the regulating valve requires a gas source pressure within a certain range. If the gas source pressure is too low or too high, the regulating valve may not work properly, and may even cause damage to the equipment. In this optional embodiment, the preset gas source pressure range is set according to the type and size of the regulating valve based on experience. In actual operation, the working pressure range marked on the nameplate of the regulating valve can be referred to and set in combination with historical data.

[0100] It can be seen that this optional embodiment monitors the gas source pressure in real time and compares it with the preset gas source pressure range, so as to promptly detect the problem of excessively high or low pressure, thereby improving the real-time and accuracy of fault diagnosis. In addition, the use of the preset gas source pressure range makes pressure monitoring more accurate, thereby improving the reliability and safety of the system.

[0101] In an optional embodiment, the diagnostic method further comprises:

[0102] Real-time collection of the usage times of the electric valve of the IP unit;

[0103] The number of uses is tested according to the preset maximum safe number of valve operations:

[0104] When the number of uses exceeds the maximum safe number of valve operations, the IP unit has an electric valve aging fault.

[0105] The life of the electric valve is limited, and excessive use may cause it to be damaged. By counting the number of times the electric valve is used and comparing it with the set alarm number, a warning can be issued in advance before the electric valve may fail, which helps to carry out maintenance or replacement in time, prevent equipment failure, and improve equipment operation stability and maintenance efficiency.

[0106] In summary, the intelligent valve positioner and IP unit fault diagnosis method disclosed in the present invention can greatly improve the efficiency and accuracy of fault diagnosis. In addition, by accurately identifying the cause of the fault, more effective maintenance reference can be provided to maintenance personnel, which helps to reduce maintenance time and cost. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0107] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. An intelligent valve positioner, characterized in that: It includes a control unit, an IP unit, a position acquisition unit and two pressure acquisition units: The IP unit is externally connected to a regulating valve, and is used to perform intake, exhaust, or holding actions according to the valve control command of the control unit to adjust the position of the regulating valve; The two pressure collection units, one of which is arranged at the air inlet of the IP unit, for measuring the air source pressure of the air inlet of the IP unit; and one of which is arranged at the air outlet of the IP unit, for measuring the output pressure of the air outlet of the IP unit; The position acquisition unit is used to measure the position of the regulating valve; The control unit is used to generate the valve control command according to the input control command and the position of the regulating valve; The control unit is also used to diagnose whether the IP unit is working abnormally according to the valve control instruction and the position of the regulating valve, and when working abnormally, start the diagnosis mode to diagnose the fault of the IP unit according to the driving voltage of the IP unit and the output pressure.

2. The intelligent valve positioner according to claim 1, characterized in that: The control unit is further used to count the number of times the electric valve of the IP unit is used, and to diagnose whether the gas source pressure and the service life of the IP unit are abnormal based on the gas source pressure and the number of times used.

3. The intelligent valve positioner according to claim 1, characterized in that: The control unit is also used to generate different diagnostic voltages to the IP unit in a diagnostic mode, collect the corresponding driving voltage of the IP unit and the output pressure, and diagnose the fault of the IP unit.

4. A method for diagnosing an IP unit failure, characterized in that: The diagnostic method is applied to the intelligent valve positioner according to any one of claims 1 to 3, and the diagnostic method comprises: Collect the position of the regulating valve in real time; diagnose whether the IP unit is working abnormally according to the expected regulating valve position corresponding to the valve control command and the position of the regulating valve; In the case of abnormal operation, the diagnostic mode of the intelligent valve positioner is turned on to collect the driving voltage and output pressure of the IP unit, and the cause of the failure of the IP unit is diagnosed accordingly.

5. A method for diagnosing an IP unit failure according to claim 4, characterized in that: The diagnostic method further comprises: Collecting the gas source pressure of the intelligent valve positioner in real time; The gas source pressure collected in real time is detected according to a preset gas source pressure range: When the gas source pressure exceeds the gas source pressure range, an abnormal gas source pressure fault occurs in the IP unit.

6. A method for diagnosing an IP unit failure according to claim 4, characterized in that: The diagnostic method further comprises: Real-time collection of the usage times of the IP unit's electric valve; The number of uses is tested according to the preset maximum safe number of valve operations: When the number of uses exceeds the maximum safe number of valve operations, the IP unit has an electric valve aging fault.

7. A method for diagnosing an IP unit failure according to claim 4, characterized in that: The step of diagnosing whether the IP unit is working abnormally according to the expected regulating valve position corresponding to the valve control command and the position of the regulating valve comprises: Compare the difference between the position of the regulating valve and the expected position of the regulating valve: If the difference is greater than a preset difference threshold, the IP unit operates abnormally; Otherwise, the IP unit works normally.

8. A method for diagnosing an IP unit failure according to claim 4, characterized in that: The step of starting the diagnostic mode of the intelligent valve positioner, collecting the driving voltage and output pressure of the IP unit, and diagnosing the cause of the failure of the IP unit accordingly comprises: Turn on the diagnostic mode of the smart valve positioner. generating a first diagnostic voltage and a second diagnostic voltage respectively, wherein the first diagnostic voltage is greater than the second diagnostic voltage; collecting a first driving voltage of the IP unit corresponding to a first diagnostic voltage and a second driving voltage of the IP unit corresponding to a second diagnostic voltage; The first driving voltage and the second driving voltage are judged according to the first diagnostic voltage and the second diagnostic voltage: When the first driving voltage and / or the second driving voltage is abnormal, the fault cause of the IP unit is the abnormal driving voltage.

9. A method for diagnosing an IP unit failure according to claim 4, characterized in that: The step of collecting the driving voltage and output pressure of the IP unit and diagnosing the cause of the failure of the IP unit accordingly comprises: The IP unit is controlled to perform different actions through valve control commands, and the output pressure of the IP unit is collected. The difference in the output pressure when performing different actions is compared, and whether the IP unit has performance abnormalities is determined based on whether the difference is less than a preset pressure difference threshold.

10. A method for diagnosing an IP unit failure according to claim 9, characterized in that: The steps of controlling the IP unit to perform different actions through the valve control command, collecting the output pressure of the IP unit, comparing the difference of the output pressure when performing different actions, and judging whether the IP unit has performance abnormality according to whether the difference is less than a preset pressure difference threshold include: The IP unit is controlled to perform exhaust action through the valve control command, and after a first preset time, the output pressure is collected as the first output pressure; The IP unit is controlled to perform the air intake action through the valve control command, and after the second preset time, the output pressure is collected as the second output pressure; The IP unit is controlled to perform a holding action through a valve control command, and after a third preset time period, the output pressure is collected as a third output pressure; Compare the first output pressure, the second output pressure, and the third output pressure with each other: When there is a pressure difference greater than a preset pressure difference threshold, the IP unit has a performance abnormality.

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