WO2018218533A1

WO2018218533A1 - Diagnosis method and diagnosis device for src exhaust gas aftertreatment system

Info

Publication number: WO2018218533A1
Application number: PCT/CN2017/086671
Authority: WO
Inventors: 姚勇; 常雁龙
Original assignee: 深圳市爱夫卡科技股份有限公司
Priority date: 2017-05-31
Filing date: 2017-05-31
Publication date: 2018-12-06

Abstract

A diagnostic method and a diagnostic device of an SRC exhaust gas aftertreatment system. The diagnostic method comprises the following steps: receiving a test command; parsing the acquired test command; sending, according to a test item, an excitation signal and a power signal respectively to a signal channel and a power supply channel of the exhaust gas aftertreatment system to be tested, so that the SCR exhaust gas aftertreatment system can respond after having received the excitation signal and the power signal and returns a responsive electrical signal; receiving the electrical signal returned by the SCR exhaust gas aftertreatment system; and analyzing the returned electrical signal by means of the fuzzy algorithm, thereby determining whether the SCR exhaust gas aftertreatment system fails. The diagnosis method for the SRC exhaust gas aftertreatment system can accurately determine a fault of the SCR exhaust gas aftertreatment system and provide a fault solution.

Description

Diagnostic method and diagnostic device for SRC exhaust gas aftertreatment system

Technical field

The invention relates to the technical field of SRC exhaust gas aftertreatment, in particular to a diagnostic method, a diagnostic device and a computer readable storage medium of an SRC exhaust gas aftertreatment system.

Background technique

In the prior art, one method used by engine manufacturers to meet the regulations on exhaust emissions is selective catalytic reduction (Selective Catalytic Reduction, SCR) Catalyst to purify nitrogen oxides in the engine's tail gas stream. The SCR exhaust aftertreatment system is a combination of mechanical, electronic, chemical and fluid sciences. In the presence of a catalyst, a reducing agent such as ammonia (NH3) is released into the exhaust gas stream of the engine. The ammonia can be stored on the surface of the catalyst. On the coating, the ammonia reacts with the nitrogen oxides in the tail gas stream to form environmentally benign products such as nitrogen and water.

When the SCR exhaust gas after-treatment system system malfunctions, such as the urea injection system is blocked, and the urea exerts a malfunction such as escape, it is difficult for the existing diagnostic device to accurately determine the failure, thereby failing to provide guidance for maintenance.

technical problem

In view of this, embodiments of the present invention provide a diagnostic method, a diagnostic apparatus, and a computer readable storage medium for an SCR exhaust aftertreatment system to accurately determine a fault of an SCR exhaust aftertreatment system.

Technical solution

A first aspect of the embodiments of the present invention provides a method for diagnosing an SCR exhaust aftertreatment system, comprising the steps of: receiving a test command; parsing the test command to obtain a test item that needs to be detected; and according to the test item, Sending an excitation signal and a power signal to the signal channel and the power channel of the SCR exhaust aftertreatment system to be tested, respectively, so that the SCR exhaust aftertreatment system responds after receiving the excitation signal and the power signal And returning a response electrical signal; receiving an electrical signal returned by the SCR exhaust aftertreatment system; and analyzing the returned electrical signal by a fuzzy algorithm to determine whether the SCR exhaust aftertreatment system is faulty.

The determining, by the fuzzy algorithm, the returned electrical signal to determine whether the SCR exhaust aftertreatment system has a fault includes the following steps: establishing a fault fuzzy set membership function; using the fault fuzzy set membership function to calculate and obtain The probability that the electrical signal characteristic returned by the SCR exhaust aftertreatment system falls within the fault fuzzy set; and comparing the probability with a preset threshold to determine whether the SCR exhaust aftertreatment system is faulty.

Wherein, before the step of transmitting the excitation signal and the power signal to the signal channel and the power channel of the SCR exhaust aftertreatment system according to the test item, the method further includes the following steps: after the SCR exhaust according to the test item The signal and/or power channels of the processing system are switched and selected for switching and selecting the excitation and/or power signals sent to the SCR exhaust aftertreatment system.

Wherein, before the step of transmitting the excitation signal and the power signal to the signal channel and the power channel of the SCR exhaust aftertreatment system according to the test item, the method further includes the following steps: the signal of the SCR exhaust aftertreatment system to be tested The channel and power channel are initialized.

The test command further includes a type of the SCR exhaust aftertreatment system. After the step of parsing the obtained test command, the method further includes the following steps: after the parsing the test item and the SCR exhaust The type of processing system transmits an excitation signal and a power signal to the signal channel and the power channel of the particular type of SCR exhaust aftertreatment system to be tested, respectively.

A second aspect of the present invention provides a diagnostic apparatus for an SCR exhaust aftertreatment system, comprising: a command receiving module for receiving a test command; and a command parsing module for interpreting the test command to obtain a test item that needs to be detected a signal sending module, configured to send, respectively, an excitation signal and a power signal to the signal channel and the power channel of the SCR exhaust aftertreatment system to be tested according to the test item, so that the SCR exhaust aftertreatment system is at the receiving station Responding to the excitation signal and the power signal, and returning a response electrical signal; an electrical signal receiving module for receiving an electrical signal returned by the SCR exhaust aftertreatment system; and a fault analysis module for passing the blur The algorithm analyzes the returned electrical signal to determine if the SCR exhaust aftertreatment system is faulty.

The fault analysis module includes: a membership function establishing sub-module, configured to establish a fault fuzzy set membership function; and a probability calculation sub-module, configured to calculate, by using the fault fuzzy set membership function, the SCR exhaust gas post-processing system to return The probability that the electrical signal characteristic falls within the fault fuzzy set; and the fault determining module is configured to compare the probability with a preset threshold to determine whether the SCR exhaust aftertreatment system has a fault.

The diagnostic device of the SCR exhaust aftertreatment system further includes a channel switching module, the channel is sent before the excitation signal and the power signal are sent to the signal channel and the power channel of the SCR exhaust aftertreatment system according to the test item. The switching module is configured to switch and select a signal channel and/or a power channel of the SCR exhaust aftertreatment system according to the test item, for switching and selecting an excitation signal sent to the SCR exhaust aftertreatment system and / or power signal.

A third aspect of the invention provides a diagnostic apparatus for a CR tail gas aftertreatment system, comprising a memory, a processor, and a computer program stored in the memory and operable on the processor, the processor executing the The computer program implements the steps of the method of any of the preceding claims.

A fourth aspect of the invention provides a computer readable storage medium storing a computer program, the computer program being executed by a processor to implement the steps of the method of any of the preceding claims.

Beneficial effect

Compared with the prior art, the embodiment of the present invention has the beneficial effects that the diagnostic method of the SCR exhaust gas aftertreatment system provided by the present invention sends an excitation signal to the signal channel of the SCR exhaust gas aftertreatment system after receiving and parsing the test command. The fuzzy signal is used to analyze the returned electrical signal, and the fault is not simply determined by the preset threshold, but the fault of the SCR exhaust aftertreatment system can be accurately determined by a single fixed preset threshold, thereby improving the accuracy of the fault test. .

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments or the description of the prior art will be briefly described below. It is obvious that the drawings in the following description are only the present invention. For some embodiments, other drawings may be obtained from those of ordinary skill in the art in light of the inventive workability.

1 is a flow chart showing a method of diagnosing an SCR exhaust gas aftertreatment system according to a first embodiment of the present invention;

2 is a schematic flow chart of a failure analysis step in the diagnosis method of the SCR exhaust gas aftertreatment system of FIG. 1;

3 is a flow chart showing a method of diagnosing an SCR exhaust gas aftertreatment system according to a second embodiment of the present invention;

4 is a schematic structural diagram of a practical application scenario of a method for diagnosing an SCR exhaust gas aftertreatment system according to various embodiments of the present invention;

Figure 5 is a schematic illustration of a diagnostic apparatus of an SCR tail gas aftertreatment system in accordance with one embodiment of the present invention;

6 is a schematic diagram of the fault analysis module of FIG. 5;

7 is a schematic diagram of a diagnostic device of an SCR exhaust aftertreatment system in accordance with one embodiment of the present invention.

Embodiments of the invention

In the following description, for purposes of illustration and description However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the invention.

In order to explain the technical solution described in the present invention, the following description will be made by way of specific embodiments.

Referring to FIG. 1, a diagnostic method 100 for an SCR exhaust aftertreatment system is provided in accordance with an embodiment of the present invention. The diagnostic method includes:

Step 101: Receive a test command;

Step 102: Parse the test command to obtain a test item that needs to be detected;

Step 103: Send an excitation signal and a power signal to the signal channel and the power channel of the SCR exhaust aftertreatment system to be tested according to the test item, so that the SCR exhaust aftertreatment system receives the excitation signal and The power signal will respond and return a response electrical signal;

Step 104: Acquire an electrical signal returned by the SCR exhaust aftertreatment system; and

Step 105: The returned electrical signal is analyzed by a fuzzy algorithm to determine whether there is a fault in the SCR exhaust aftertreatment system. In addition, when the selected test item is tested, return to the test completion command and wait for the test command until the next test.

The diagnostic method 100 of the SCR tail gas aftertreatment system according to the present invention employs a fuzzy algorithm to determine a system failure, instead of performing fault determination by a single preset threshold in the prior art, thereby improving the accuracy of the fault test.

It should be noted that the SCR exhaust gas aftertreatment system according to an embodiment of the present invention is generally an SCR post-treatment urea pump, and the SCR post-treatment urea pump generally includes: a motor, an electromagnetic reversing valve, a nozzle solenoid valve, a heating solenoid valve, and an air exchange. To solenoid valve and DCU ((Dosing Control Unit, urea injection control unit, etc. Of course, the SCR exhaust aftertreatment system here can also be other devices installed in the car.

Referring to FIG. 2, in particular, in the diagnostic method 100 of the SCR exhaust aftertreatment system according to the embodiment of the present invention, step S105 is to analyze the returned electrical signal by a fuzzy algorithm to determine whether the SCR exhaust aftertreatment system is A fault includes the following steps:

Step 151: Establish a fault fuzzy set membership function;

Step 152: Calculate the probability that the electrical signal feature returned by the acquired SCR exhaust aftertreatment system falls within the fault fuzzy set by using the fault fuzzy set membership function; and

Step 153: Compare the probability with the preset threshold to determine whether there is a fault in the SCR exhaust aftertreatment system. For example, when the probability is greater than the threshold, it is determined that the SCR exhaust aftertreatment system has a fault, and vice versa.

The diagnostic method 100 of the SCR exhaust aftertreatment system according to the embodiment of the present invention determines the failure of the SCR exhaust aftertreatment system by the above-described fuzzy algorithm, instead of performing fault determination by a single fixed preset threshold in the prior art, thereby enabling Improve the accuracy of fault testing.

Hereinafter, a diagnosis method 200 of the SCR exhaust gas aftertreatment system according to the second embodiment of the present invention will be described with reference to FIG. 3. The diagnostic method 200 of the SCR tail gas aftertreatment system includes the following steps:

Step 201: Receive a test command.

Step 202: Parse the test command to obtain a test item that needs to be detected, and the test command further includes a type of the SCR exhaust aftertreatment system, so that a specific type of SCR exhaust aftertreatment system can be targeted. Testing to further improve the accuracy of the test;

Step 203: Switching and selecting a signal channel and a power channel of the SCR exhaust aftertreatment system for switching and selecting an excitation signal and/or a power signal sent to the SCR exhaust aftertreatment system, thereby being compatible with different types of SCR exhaust aftertreatment system, therefore, for different SCR exhaust aftertreatment systems, you can use a variety of drive circuits to reduce system coupling and hardware costs;

Step 204: Initializing the signal channel and the power channel of the SCR exhaust aftertreatment system to be tested, thereby eliminating the influence of the previous test on the signal channel and the power channel of the SCR exhaust aftertreatment system to further improve fault diagnosis Accuracy

Step 205: Send an excitation signal and a power signal to the signal channel and the power channel of the specific type of the SCR exhaust gas aftertreatment system to be tested according to the type of the test item and the SCR exhaust aftertreatment system, respectively. The SCR exhaust aftertreatment system responds after receiving the excitation signal and the power signal, and returns a response electrical signal, such as a current and voltage signal returned by the SCR exhaust aftertreatment system;

Step 206: Acquire an electrical signal returned by the SCR exhaust aftertreatment system; and

Step 207: The returned electrical signal is analyzed by a fuzzy algorithm to determine whether there is a fault in the SCR exhaust aftertreatment system. In addition, when the selected test item is tested, return to the test completion command and wait for the test command until the next test.

The diagnostic method 200 of the SCR exhaust aftertreatment system according to the second embodiment of the present invention determines the failure of the SCR exhaust aftertreatment system by the above-described fuzzy algorithm, instead of performing the failure judgment by a single fixed preset threshold in the prior art. Thereby, the accuracy of the fault test can be improved.

It should be noted that in the diagnostic method 200 of the SCR exhaust aftertreatment system according to the second embodiment of the present invention, the order of steps 203 and 204 may be interchanged without affecting the implementation of the above diagnostic method, but step 203 is preferably located. Before step 204.

In practical applications, referring to FIG. 4, a schematic structural diagram of a practical application scenario of a diagnosis method of an SCR exhaust gas aftertreatment system according to various embodiments of the present invention, wherein, in practical applications, a diagnosis method using the above SCR exhaust gas aftertreatment system The diagnostic device includes a host computer 1 and a lower computer 2, wherein the host computer 1 is connected to the lower computer 2, and the lower computer 2 is connected to the SCR exhaust gas aftertreatment system 4 through the diagnostic connector 3. The host computer 1 refers to an embedded computer that can directly issue control commands. The lower computer 2 refers to a computer that directly controls the device to acquire the condition of the device. In the diagnostic method of the SCR exhaust gas aftertreatment system according to the embodiment of the present invention, the lower computer 2 includes a host, a serial port interface, a DB26 interface, a driving circuit, and the like. For example, in the above-described diagnostic method of the SCR exhaust gas aftertreatment system according to various embodiments of the present invention, the upper computer 1 is configured to transmit a test command, and the lower computer 2 receives the test command of the upper computer, and sequentially performs the above steps 101 to 105 or step 201 to step 207, when the test is completed, the lower computer 2 will return the test completion command to the upper computer 1, and wait for the upper computer 1 command until the next test.

Referring to FIG. 5, a diagnostic apparatus 50 for an SCR exhaust aftertreatment system according to an embodiment of the present invention includes:

The command receiving module 51 is configured to receive a test command.

a command parsing module 52, configured to interpret the obtained test command to obtain a test item that needs to be detected;

The signal sending module 53 is configured to respectively send an excitation signal and a power signal to the signal channel and the power channel of the SCR exhaust aftertreatment system to be tested according to the test item, so that the SCR exhaust aftertreatment system receives the The excitation signal and the power signal will respond and return a response electrical signal;

An electrical signal acquisition module 54 for obtaining an electrical signal returned by the SCR exhaust aftertreatment system; and

The fault analysis module 55 is configured to analyze the returned electrical signal by using a fuzzy algorithm to determine whether the SCR exhaust aftertreatment system has a fault. In addition, when the selected test item is tested, return to the test completion command and wait for the test command until the next test.

The diagnostic device of the SCR exhaust gas aftertreatment system according to the present invention uses a fuzzy algorithm to determine a system failure, instead of using a single preset threshold for fault diagnosis in the prior art, thereby being able to adapt to different types of SCR exhaust aftertreatment systems, and further Can improve the accuracy of fault testing.

Referring to FIG. 6, in particular, in the diagnostic apparatus of the SCR exhaust aftertreatment system according to the embodiment of the present invention, the failure analysis module 55 includes:

a membership function establishing sub-module 551, configured to establish a fault fuzzy set membership function;

a probability calculation sub-module 552, configured to calculate, by using the fault fuzzy set membership function, a probability that an electrical signal feature returned by the acquired SCR exhaust after-treatment system falls within the fault fuzzy set; and

The fault determination sub-module 153 is configured to compare the probability with the threshold to determine whether the SCR exhaust after-treatment system has a fault. For example, when the probability is greater than the threshold, it is determined that the SCR exhaust after-treatment system has a fault, and vice versa.

The diagnostic apparatus of the SCR exhaust gas after-treatment system according to the embodiment of the present invention determines the fault of the SCR exhaust gas after-treatment system by the above-described fuzzy algorithm, instead of performing fault diagnosis by a preset threshold in the prior art, thereby being able to adapt to different types. The SCR exhaust aftertreatment system can improve the accuracy of fault testing.

Further, the diagnostic apparatus of the SCR exhaust aftertreatment system according to an embodiment of the present invention further includes a channel switching module (not shown) that, in accordance with the test item, signal channels and power channels to the SCR exhaust aftertreatment system Before transmitting the excitation signal and the power signal, the channel switching module is configured to switch and select a signal channel and/or a power channel of the SCR exhaust aftertreatment system according to the test item, for switching and selecting to send to The excitation signal and/or power signal of the SCR exhaust aftertreatment system can be compatible with various SCR exhaust aftertreatment systems, and various drive circuits can be multiplexed for different SCR exhaust aftertreatment systems to reduce system coupling and Hardware cost. In practical applications, the channel switching module transmits a channel switching signal to the multiplexer, thereby switching and selecting the excitation signal and/or the power signal through the multiplexer.

Of course, the diagnostic apparatus of the SCR exhaust aftertreatment system of the embodiment of the present invention according to an embodiment of the present invention may further include a channel initialization module (not shown) for processing the system to the SCR exhaust gas according to the test item. Before the signal channel and the power channel send the excitation signal and the power signal, the channel initialization module is configured to initialize the signal channel and the power channel of the SCR exhaust aftertreatment system to be tested, and the channel initialization module is used for testing The signal path and power output channel of the SCR exhaust aftertreatment system are initialized, which can eliminate the influence of previous tests on the signal channel and power channel of the SCR exhaust aftertreatment system to further improve the accuracy of fault diagnosis.

Further, in the diagnostic apparatus of the SCR exhaust aftertreatment system according to the embodiment of the present invention, the test command further includes the type of the SCR exhaust aftertreatment system, and the signal transmitting module parses the acquired After the test command, according to the parsed test item and the type of the SCR exhaust aftertreatment system, the excitation signal and the power supply are respectively sent to the signal channel and the power channel of the specific type of the SCR exhaust aftertreatment system to be tested. Signals to perform targeted tests on specific types of SCR exhaust aftertreatment systems to further improve detection accuracy.

It should be understood that the size of the sequence of the steps in the above embodiments does not imply a sequence of executions, and the order of execution of the processes should be determined by its function and internal logic, and should not be construed as limiting the implementation of the embodiments of the present invention.

Figure 7 is a schematic illustration of a diagnostic device 70 of an SCR exhaust aftertreatment system in accordance with one embodiment of the present invention. As shown in FIG. 7, the diagnostic apparatus of the SCR exhaust aftertreatment system of this embodiment includes a processor 71, a memory 72, and a computer program 73 stored in the memory 72 and operable on the processor 71. The steps in the various method embodiments of the diagnostic method of the SCR exhaust aftertreatment system described above when the processor 71 executes the computer program 73, such as steps 101 to 105 shown in FIG. Alternatively, the processor 71 implements the functions of the modules in the respective device embodiments, such as the functions of the modules 51 to 55 shown in FIG. 5, when the computer program 73 is executed.

Illustratively, the computer program 73 can be partitioned into one or more modules that are stored in the memory 72 and executed by the processor 71 to complete the present invention. The one or more modules may be a series of computer program instructions that are capable of performing a particular function, the instruction segments being used to describe the execution of the computer program 73 in a diagnostic device of the SCR exhaust aftertreatment system. For example, the computer program 73 may be divided into a command receiving module, a command parsing module, an excitation signal sending module, an electrical signal acquiring module, and a fault analysis module. The specific functions of each module may refer to the above content, and thus are not described herein.

The diagnostic device of the SCR exhaust aftertreatment system may be a computing device such as a desktop computer, a notebook, a palmtop computer, and a cloud server. The diagnostic device of the SCR exhaust aftertreatment system may include, but is not limited to, processor 71, memory 72. It will be understood by those skilled in the art that FIG. 7 is merely an example of a diagnostic device of the SCR exhaust aftertreatment system and does not constitute a limitation to the diagnostic device of the SCR exhaust aftertreatment system, and may include more or fewer components than those illustrated. Alternatively, some components may be combined, or different components, such as the diagnostic device of the SCR exhaust aftertreatment system, may also include input and output devices, network access devices, buses, and the like.

The so-called processor 71 can be a central processing unit (Central Processing Unit, CPU), can also be other general-purpose processors, digital signal processors (DSP), ASICs (Application Specific Integrated Circuit, ASIC), off-the-shelf programmable gate array (Field-Programmable) Gate Array, FPGA) Or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, and the like. The general purpose processor may be a microprocessor or the processor or any conventional processor or the like.

The memory 72 may be an internal storage unit of the diagnostic device 70 of the SCR exhaust aftertreatment system, such as a hard disk or memory of the diagnostic device 70 of the SCR exhaust aftertreatment system. The memory 72 may also be an external storage device of the diagnostic device 70 of the SCR exhaust aftertreatment system, such as a plug-in hard disk equipped with the diagnostic device 70 of the SCR exhaust aftertreatment system, and a smart memory card (Smart Media Card, SMC), Secure Digital (SD) card, flash card (Flash) Card) and so on. Further, the memory 72 may also include an internal storage unit of the diagnostic device 70 of the SCR exhaust aftertreatment system and an external storage device. The memory 72 is used to store the computer program and other programs and data required by the diagnostic device 70 of the SCR exhaust aftertreatment system. The memory 72 can also be used to temporarily store data that has been or will be output.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the division of each functional unit and module described above is exemplified. In practical applications, the above functions may be assigned to different functional units as needed. The module is completed by dividing the internal structure of the device into different functional units or modules to perform all or part of the functions described above. Each functional unit and module in the embodiment may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit, and the integrated unit may be hardware. Formal implementation can also be implemented in the form of software functional units. In addition, the specific names of the respective functional units and modules are only for the purpose of facilitating mutual differentiation, and are not intended to limit the scope of protection of the present application. For the specific working process of the unit and the module in the foregoing system, reference may be made to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the above embodiments, the descriptions of the various embodiments are different, and the parts that are not detailed or described in a certain embodiment can be referred to the related descriptions of other embodiments.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

In the embodiments provided by the present invention, it should be understood that the disclosed apparatus/terminal device and method may be implemented in other manners. For example, the device/terminal device embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units. Or components may be combined or integrated into another system, or some features may be omitted or not performed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

The integrated modules/units, if implemented in the form of software functional units and sold or used as separate products, may be stored in a computer readable storage medium. Based on such understanding, the present invention implements all or part of the processes in the foregoing embodiments, and may also be completed by a computer program to instruct related hardware. The computer program may be stored in a computer readable storage medium. The steps of the various method embodiments described above may be implemented when the program is executed by the processor. . Wherein, the computer program comprises computer program code, which may be in the form of source code, object code form, executable file or some intermediate form. The computer readable medium can include any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a removable hard drive, a magnetic disk, an optical disk, a computer memory, a read only memory (ROM, Read-Only) Memory), random access memory (RAM, Random Access Memory), electrical carrier signals, telecommunications signals, and software distribution media. It should be noted that the content contained in the computer readable medium may be appropriately increased or decreased according to the requirements of legislation and patent practice in a jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, computer readable media Does not include electrical carrier signals and telecommunication signals.

The embodiments described above are only for explaining the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art will understand that The technical solutions described in the examples are modified, or some of the technical features are equivalently replaced; and the modifications or substitutions do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in Within the scope of protection of the present invention.

Claims

A method for diagnosing an SCR tail gas aftertreatment system, comprising the steps of:

Receiving test commands;

Parsing the test command to obtain a test item that needs to be tested;

And transmitting, according to the test item, an excitation signal and a power signal to the signal channel and the power channel of the SCR exhaust aftertreatment system to be tested, so that the SCR exhaust aftertreatment system receives the excitation signal and the power source The signal will respond and return the electrical signal of the response;

Receiving an electrical signal returned by the SCR exhaust aftertreatment system; and

The returned electrical signal is analyzed by a fuzzy algorithm to determine if the SCR exhaust aftertreatment system is faulty.
The method of diagnosing an SCR exhaust aftertreatment system according to claim 1, wherein said analyzing said returned electrical signal by a fuzzy algorithm to determine whether said SCR exhaust aftertreatment system is faulty comprises the following steps :

Establish a fault fuzzy set membership function;

Calculating, by using the fault fuzzy set membership function, a probability that an electrical signal feature returned by the SCR exhaust aftertreatment system falls within the fault fuzzy set; and

Comparing the probability with a preset threshold to determine whether the SCR exhaust aftertreatment system has a fault.
A method for diagnosing an SCR exhaust gas aftertreatment system according to claim 1 or 2, wherein, in accordance with said test item, an excitation signal and a power supply signal are transmitted to a signal channel and a power supply channel of said SCR exhaust gas aftertreatment system Before the step, the method further includes the following steps: switching and selecting a signal channel and/or a power channel of the SCR exhaust aftertreatment system for switching and selecting for transmission to the SCR exhaust aftertreatment system according to the test item Excitation signal and / or power signal.
A method of diagnosing an SCR exhaust aftertreatment system according to claim 1 wherein prior to said step of transmitting an excitation signal and a power signal to said signal path and power path of said SCR tail gas aftertreatment system in accordance with said test item The method further includes the following steps: initializing the signal channel and the power channel of the SCR exhaust aftertreatment system to be tested.
A method of diagnosing an SCR tail gas aftertreatment system according to claim 1, wherein

The test command further includes a type of the SCR exhaust aftertreatment system. After the step of parsing the obtained test command, the method further includes the following steps: the parsing the test item and the SCR exhaust aftertreatment system A type that transmits an excitation signal and a power signal to a signal channel and a power channel of the particular type of SCR exhaust aftertreatment system to be tested, respectively.
A diagnostic device for an SCR exhaust gas aftertreatment system, comprising:

a command receiving module, configured to receive a test command;

a command parsing module, configured to interpret the test command to obtain a test item that needs to be tested;

a signal sending module, configured to respectively send an excitation signal and a power signal to the signal channel and the power channel of the SCR exhaust aftertreatment system to be tested according to the test item, so that the SCR exhaust aftertreatment system receives the The excitation signal and the power signal will respond and return a response electrical signal;

An electrical signal receiving module for receiving an electrical signal returned by the SCR exhaust aftertreatment system; and

The fault analysis module is configured to analyze the returned electrical signal by a fuzzy algorithm to determine whether the SCR exhaust aftertreatment system has a fault.
The diagnostic device of the SCR exhaust aftertreatment system of claim 6, wherein the failure analysis module comprises:

A membership function sub-module is used to establish a fault fuzzy set membership function;

a probability calculation submodule, configured to calculate, by using the fault fuzzy set membership function, a probability that an electrical signal feature returned by the SCR exhaust aftertreatment system falls within the fault fuzzy set; and

The fault determination sub-module is configured to compare the probability with a preset threshold to determine whether the SCR exhaust after-treatment system has a fault.
A diagnostic apparatus for an SCR exhaust aftertreatment system according to claim 6, further comprising a channel switching module for transmitting an excitation signal to a signal channel and a power channel of said SCR exhaust aftertreatment system according to said test item And the power switching signal, the channel switching module is configured to switch and select a signal channel and/or a power channel of the SCR exhaust aftertreatment system according to the test item, for switching and selecting to send to the SCR The excitation signal and/or power signal of the exhaust aftertreatment system.
A diagnostic device for an SCR exhaust aftertreatment system, comprising a memory, a processor, and a computer program stored in the memory and operative on the processor, wherein the processor executes the computer program The steps of the method of any one of claims 1 to 5.
A computer readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the steps of the method of any one of claims 1 to 5.