A method and device for testing a three-way catalytic converter

Abstract

The three-way catalytic converter testing method and device provided by the embodiments of the present application, the method includes: judging whether the vehicle supports the fuel injection quantity collaborative air-fuel ratio sensor test according to the decentralized identifier; judging whether the voltage determination method or the current determination method is supported according to the PID identifier of the oxygen sensor or the air-fuel ratio sensor, and if supported, performing the voltage determination method or the current determination method for testing; sequentially executing the fuel injection quantity collaborative air-fuel ratio sensor richening instruction and the leanening instruction a predetermined number of times, and judging the performance of the three-way catalytic converter according to the time difference between the start of executing the leanening instruction and the completion of the leanening instruction. The present application monitors the time that the voltage and current of the oxygen sensor or the air-fuel ratio sensor reach the specified range through the richening and leanening fuel injection quantities during the fuel injection quantity collaborative air-fuel ratio sensor test, so as to quickly and efficiently judge the performance of the three-way catalytic converter, and the operation is simple, and the time cost can be saved.

Description

Technical Field

[0001] This application relates to the technical field of automobiles, and particularly to a method and device for testing a three-way catalytic converter. Background Art

[0002] A three-way catalytic converter is a purification device installed in the exhaust system of an automobile. It can convert harmful gases such as CO, HC, and NOx in automobile exhaust into harmless carbon dioxide, water, and nitrogen through oxidation-reduction reactions, playing a crucial role in the field of automobile environmental protection. With the increase in the service life of automobiles, the aging problem of the three-way catalytic converter cannot be ignored. Currently, existing detection methods include: visual inspection, such as observing depressions, obvious scratches, and spots on the surface of the catalytic converter; backpressure test, such as manually drilling a hole at the front end of the catalytic converter and connecting a pressure gauge, and checking the backpressure when the engine speed rises from idle to 2500 revolutions per minute; vacuum test, such as connecting a vacuum gauge to the intake manifold and observing the scale change of the vacuum gauge when the engine speed rises from idle to 2500 revolutions per minute, etc.

[0003] The above methods can only check for mechanical failures of the three-way catalytic converter, cannot reflect the performance, and are cumbersome to operate with a high complexity. Summary of the Invention

[0004] This application provides a method and device for testing a three-way catalytic converter.

[0005] According to the first aspect of this application, a method for testing a three-way catalytic converter is provided, including:

[0006] Judging whether the vehicle supports the fuel injection quantity coordinated with the air-fuel ratio sensor test according to the decentralized identifier. When the vehicle supports the fuel injection quantity coordinated with the air-fuel ratio sensor test, start the test;

[0007] Judging whether the current vehicle model supports the voltage determination method or the current determination method according to the PID identifier of the oxygen sensor or the air-fuel ratio sensor. If it supports, perform the test using the voltage determination method or the current determination method;

[0008] Sequentially execute a predetermined number of fuel injection quantity coordinated with the air-fuel ratio sensor rich commands and lean commands, and judge the performance of the three-way catalytic converter according to the time difference between the start of executing the fuel injection quantity coordinated with the air-fuel ratio sensor lean command and the completion of the fuel injection quantity coordinated with the air-fuel ratio sensor lean command.

[0009] Further, the judging whether the current vehicle model supports the voltage determination method or the current determination method according to the PID identifier of the oxygen sensor or the air-fuel ratio sensor includes:

[0010] Establish a communication connection with the engine ECU;

[0011] Read the PID identifier, and perform a search in combination with the database. If the oxygen sensor or the air-fuel ratio sensor voltage PID is matched, it is determined that the voltage determination method is supported; otherwise, the voltage determination method is not supported.

[0012] When the voltage determination method is not supported, perform a search in combination with the database. If the oxygen sensor or the air-fuel ratio sensor current PID is matched, it is determined that the current determination method is supported; otherwise, the current determination method is not supported.

[0013] Furthermore, execute the fuel injection quantity collaborative air-fuel ratio sensor enrichment instruction and the lean instruction a predetermined number of times in sequence, and judge the performance of the three-way catalytic converter according to the time difference between the start of executing the fuel injection quantity collaborative air-fuel ratio sensor lean instruction and the completion of the fuel injection quantity collaborative air-fuel ratio sensor lean instruction, including:

[0014] Execute the fuel injection quantity collaborative air-fuel ratio sensor +12.5% enrichment instruction for the first preset number of times. At this time, the voltage of the oxygen sensor or the air-fuel ratio sensor rises.

[0015] Execute the fuel injection quantity collaborative air-fuel ratio sensor -12.5% lean instruction for the second preset number of times, and record the current system time T1 at the start of execution. At this time, the voltage of the oxygen sensor or the air-fuel ratio sensor drops. When it drops to the first threshold, record the current system time T2, and calculate the time difference T2 - T1.

[0016] Repeat a predetermined number of times, and calculate the first average value T of the time difference U 。

[0017] When the first average value T U is greater than 5 seconds, it is determined that the three-way catalytic is good. When the first average value T U is less than or equal to 5 seconds and greater than or equal to 2 seconds, it is determined that the three-way catalytic is in a sub-healthy state. When the first average value T U is less than 2 seconds, it is determined that the three-way catalytic is in a faulty state.

[0018] Furthermore, the fuel injection quantity collaborative air-fuel ratio sensor enrichment instruction and the lean instruction are executed a predetermined number of times in sequence, and the performance of the three-way catalytic converter is judged according to the time difference between the start of executing the fuel injection quantity collaborative air-fuel ratio sensor lean instruction and the completion of the fuel injection quantity collaborative air-fuel ratio sensor lean instruction, including:

[0019] Execute the fuel injection quantity collaborative air-fuel ratio sensor +12.5% enrichment instruction for the third preset number of times. At this time, the current of the oxygen sensor or the air-fuel ratio sensor drops.

[0020] Execute the fourth preset number of fuel injection quantity collaborative air-fuel ratio sensor -12.5% lean addition instructions, and record the current system time T3 when starting to execute. At this time, the oxygen sensor current or the air-fuel ratio sensor current rises. When it rises to be greater than the second threshold, record the current system time T4, and calculate the time difference T4 - T3;

[0021] Repeat a predetermined number of times, and calculate the second average value T of the time difference I ;

[0022] When the second average value T I is greater than 5 seconds, it is determined that the three-way catalyst is in good condition. When the second average value T I is less than or equal to 5 seconds and greater than or equal to 2 seconds, it is determined that the three-way catalyst is in a sub-healthy state. When the first average value T I is less than 2 seconds, it is determined that the three-way catalyst is in a faulty state.

[0023] Further, according to the decentralized identifier, it is determined whether the vehicle supports the fuel injection quantity collaborative air-fuel ratio sensor test. When the vehicle supports the fuel injection quantity collaborative air-fuel ratio sensor test, the test is started, including:

[0024] Establish a communication connection with the engine ECU;

[0025] Read the first decentralized identifier that supports the action test;

[0026] Combine with the database to search. If the second decentralized identifier of the EGR valve step position is matched, it is determined to be supported, otherwise it is not supported.

[0027] According to the second aspect of the present application, the present application provides a three-way catalyst test device, including:

[0028] The first judgment module is used to judge whether the vehicle supports the fuel injection quantity collaborative air-fuel ratio sensor test according to the decentralized identifier. When the vehicle supports the fuel injection quantity collaborative air-fuel ratio sensor test, the test is started;

[0029] The second judgment module is used to judge whether the current vehicle model supports the voltage judgment method or the current judgment method according to the PID identifier of the oxygen sensor or the air-fuel ratio sensor. If it supports, the voltage judgment method or the current judgment method is used for testing;

[0030] The processing module is used to sequentially execute a predetermined number of fuel injection quantity collaborative air-fuel ratio sensor enrichment instructions and lean addition instructions, and judge the performance of the three-way catalyst according to the time difference between starting to execute the fuel injection quantity collaborative air-fuel ratio sensor lean addition instruction and completing the fuel injection quantity collaborative air-fuel ratio sensor lean addition instruction.

[0031] Further, the second judgment module includes:

[0032] A second communication unit for establishing a communication connection with the engine ECU;

[0033] A voltage judgment unit for reading the PID identifier, searching in combination with a database, and if the voltage PID of the oxygen sensor or the air-fuel ratio sensor is matched, it is determined that the voltage judgment method is supported, otherwise the voltage judgment method is not supported;

[0034] A current judgment unit for searching in combination with a database when the voltage judgment method is not supported. If the current PID of the oxygen sensor or the air-fuel ratio sensor is matched, it is determined that the current judgment method is supported, otherwise the current judgment method is not supported.

[0035] Further, the processing module includes:

[0036] A first enrichment unit for executing the first preset number of times of the fuel injection quantity coordinated with the air-fuel ratio sensor +12.5% enrichment instruction. At this time, the voltage of the oxygen sensor or the air-fuel ratio sensor rises;

[0037] A first lean unit for executing the second preset number of times of the fuel injection quantity coordinated with the air-fuel ratio sensor -12.5% lean instruction, and recording the current system time T1 at the start of execution. At this time, the voltage of the oxygen sensor or the air-fuel ratio sensor drops. When it drops to the first threshold, record the current system time T2, and calculate the time difference T2 - T1;

[0038] A first calculation unit for repeating a predetermined number of times to calculate the first average value T of the time difference U .

[0039] A first processing unit for when the first average value T U is greater than 5 seconds, it is determined that the three-way catalyst is in good condition. When the first average value T U is less than or equal to 5 seconds and greater than or equal to 2 seconds, it is determined that the three-way catalyst is in a sub-healthy state. When the first average value T U is less than 2 seconds, it is determined that the three-way catalyst is in a faulty state.

[0040] Further, the processing module includes:

[0041] A second enrichment unit for executing the third preset number of times of the fuel injection quantity coordinated with the air-fuel ratio sensor +12.5% enrichment instruction. At this time, the current of the oxygen sensor or the air-fuel ratio sensor drops;

[0042] A second lean unit for executing the fourth preset number of times of the fuel injection quantity coordinated with the air-fuel ratio sensor -12.5% lean instruction, and recording the current system time T3 at the start of execution. At this time, the current of the oxygen sensor or the air-fuel ratio sensor rises. When it rises to be greater than the second threshold, record the current system time T4, and calculate the time difference T4 - T3;

[0043] A second calculation unit, configured to calculate a second average value T of the time difference by repeating a predetermined number of times. I ;

[0044] A second processing unit, configured to determine that the three-way catalyst is in good condition when the second average value T I is greater than 5 seconds, determine that the three-way catalyst is in a sub-healthy state when the second average value T I is less than or equal to 5 seconds and greater than or equal to 2 seconds, and determine that the three-way catalyst is in a faulty state when the first average value T I is less than 2 seconds.

[0045] Further, the first determination module includes:

[0046] A first communication unit, configured to establish a communication connection with the engine ECU;

[0047] A reading unit, configured to read a first decentralized identifier that supports the action test;

[0048] A matching unit, configured to perform a search in combination with a database, and if a second decentralized identifier of the EGR valve stepping position is matched, it is determined to be supported, otherwise it is determined to be not supported.

[0049] According to a third aspect of the present application, the present application provides a three-way catalyst test device, including:

[0050] A memory, configured to store a program;

[0051] A processor, configured to implement the above method by executing the program stored in the memory.

[0052] Due to the adoption of the above technical solutions, the beneficial effects of the present application are as follows:

[0053] The method and device for testing a three-way catalytic converter provided by an embodiment of the present application. The method includes: judging whether a vehicle supports the test of fuel injection quantity in cooperation with an air-fuel ratio sensor according to a decentralized identifier. When the vehicle supports the test of fuel injection quantity in cooperation with an air-fuel ratio sensor, the test is started; judging whether the current vehicle model supports the voltage determination method or the current determination method according to the PID identifier of an oxygen sensor or an air-fuel ratio sensor. If it supports, the voltage determination method or the current determination method is used for testing; successively executing a fuel injection quantity in cooperation with an air-fuel ratio sensor rich command and a lean command a predetermined number of times, and judging the performance of the three-way catalytic converter according to the time difference between the start time of executing the fuel injection quantity in cooperation with an air-fuel ratio sensor lean command and the completion time of the fuel injection quantity in cooperation with an air-fuel ratio sensor lean command. By monitoring the time that the voltage and current of the oxygen sensor or the air-fuel ratio sensor reach a specified range through the rich and lean fuel injection quantities in the test process of the fuel injection quantity in cooperation with an air-fuel ratio sensor, the embodiment of the present application can quickly and efficiently judge the performance of the three-way catalytic converter, and the operation is simple, which can save time costs. Description of the Drawings

[0054] Figure 1 It is a flowchart of the method for testing a three-way catalytic converter provided by Embodiment 1 of the present application in one implementation manner;

[0055] Figure 2 It is a flowchart of the method for testing a three-way catalytic converter provided by Embodiment 1 of the present application in another implementation manner;

[0056] Figure 3 It is a flowchart of the method for testing a three-way catalytic converter provided by Embodiment 1 of the present application in yet another implementation manner;

[0057] Figure 4 It is a flowchart of the method for testing a three-way catalytic converter provided by Embodiment 1 of the present application in yet another implementation manner;

[0058] Figure 5 It is a flowchart of the method for testing a three-way catalytic converter provided by Embodiment 1 of the present application in yet another implementation manner;

[0059] Figure 6 It is a schematic diagram of program modules of the device for testing a three-way catalytic converter provided by Embodiment 2 of the present application in one implementation manner;

[0060] Figure 7 It is a schematic diagram of program modules of the second judgment module provided by Embodiment 2 of the present application in one implementation manner;

[0061] Figure 8 It is a schematic diagram of program modules of the processing module provided by Embodiment 2 of the present application in one implementation manner;

[0062] Figure 9Schematic diagram of the program module of the processing module provided in the second embodiment of the present application in another implementation manner;

[0063] Figure 10 Schematic diagram of the program module of the first judgment module provided in the second embodiment of the present application in one implementation manner. Detailed implementation manner

[0064] The present invention will be further described in detail below in conjunction with the accompanying drawings through specific implementation manners. Similar elements in different implementation manners are labeled with related similar element numbers. In the following implementation manners, many detailed descriptions are provided to enable a better understanding of the present application. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification to avoid overwhelming the core part of the present application with excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the descriptions in the specification and general technical knowledge in the field.

[0065] In addition, the features, operations, or characteristics described in the specification can be combined in any appropriate manner to form various implementation manners. At the same time, the steps or actions in the method description can also be reordered or adjusted in an obvious manner by those skilled in the art. Therefore, the various sequences in the specification and drawings are only for clearly describing a certain embodiment and do not mean that they are the necessary sequences unless it is stated that a certain sequence must be followed.

[0066] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meanings. The "connection" and "coupling" mentioned in the present application, unless otherwise specified, both include direct and indirect connections (couplings).

[0067] Embodiment 1:

[0068] As Figure 1 shown, a method for testing a three-way catalytic converter provided in Embodiment 1 of the present application, in one implementation manner, includes the following steps:

[0069] Step 101: According to the Decentralized Identifier (DID), determine whether the vehicle supports the fuel injection volume coordinated with the air-fuel ratio sensor test. When the vehicle supports the fuel injection volume coordinated with the air-fuel ratio sensor test, start the test.

[0070] Further, as Figure 2As shown, step 101 may specifically include the following steps:

[0071] Step 1011: Establish a communication connection with the engine ECU (Electronic Control Unit).

[0072] Step 1012: Read the first DID that supports the action test.

[0073] Step 1013: Combine with the database to search. If the second DID of the EGR valve step position is matched, it is determined that the vehicle supports the fuel injection volume coordinated with the air-fuel ratio sensor test; otherwise, it does not support.

[0074] By communicating with the engine ECU to read the DID identifier supported by the action test and combining with the database to search, if the DID of the fuel injection volume coordinated with the air-fuel ratio sensor test is matched, it is determined that the vehicle supports the fuel injection volume coordinated with the air-fuel ratio sensor test; otherwise, it is determined that the vehicle does not support the fuel injection volume coordinated with the air-fuel ratio sensor test. The DID of each function can be defined independently by Toyota and Lexus manufacturers.

[0075] Step 102: According to the PID (Parameter Identifier) of the oxygen sensor or the air-fuel ratio sensor, determine whether the current vehicle model supports the voltage determination method or the current determination method. If it supports, perform the voltage determination method or the current determination method for testing.

[0076] Further, as Figure 3 shown, step 102 may specifically include the following steps:

[0077] Step 1021: Establish a communication connection with the engine ECU.

[0078] Step 1022: Read the PID identifier and combine with the database to search. If the voltage PID of the oxygen sensor or the air-fuel ratio sensor is matched, it is determined that the voltage determination method is supported; otherwise, it is not supported.

[0079] By communicating with the engine ECU to read the PID identifier supported by the data stream and combining with the database to search, if the voltage PID of the oxygen sensor or the air-fuel ratio sensor is matched, it is determined that the voltage determination method is supported; otherwise, it is not supported. The PID of each function can be defined independently by manufacturers such as Toyota and Lexus.

[0080] Step 1023: When the voltage determination method is not supported, combine with the database to search. If the current PID of the oxygen sensor or the air-fuel ratio sensor is matched, it is determined that the current determination method is supported; otherwise, it is not supported.

[0081] Read the PID identifiers supported by the data stream through communication with the engine ECU, and search in combination with the database. If the oxygen sensor or air-fuel ratio sensor current PID is matched, it is determined that the current determination method is supported; otherwise, the current determination method is not supported.

[0082] Step 103: Sequentially execute the fuel injection quantity collaborative air-fuel ratio sensor enrichment instruction and lean instruction a predetermined number of times, and judge the performance of the three-way catalytic converter according to the time difference between the start of executing the fuel injection quantity collaborative air-fuel ratio sensor lean instruction and the completion of the fuel injection quantity collaborative air-fuel ratio sensor lean instruction.

[0083] Further, as Figure 4 shown, step 103 may specifically further include the following steps:

[0084] Step 1031: Execute the fuel injection quantity collaborative air-fuel ratio sensor +12.5% enrichment instruction for the first preset number of times, and at this time, the oxygen sensor voltage or air-fuel ratio sensor voltage rises.

[0085] Step 1032: Execute the fuel injection quantity collaborative air-fuel ratio sensor -12.5% lean instruction for the second preset number of times, and record the current system time T1 when starting to execute. At this time, the oxygen sensor voltage or air-fuel ratio sensor voltage drops. When it drops to the first threshold, record the current system time T2, and calculate the time difference T2 - T1.

[0086] Step 1033: Repeat a predetermined number of times, and calculate the first average value T of the time difference U .

[0087] In one embodiment, code can be written to execute the fuel injection quantity coordinated with the air-fuel ratio sensor +12.5% enrichment instruction for a first preset number of times, and the first preset number of times can be set as needed. In this embodiment, the value range of the first preset number of times is 280 - 320 times, and in this embodiment, the first preset number of times can be 300 times (the preset number of times in this application are all implementation data and can be modified as needed). During this process, the oxygen sensor voltage or the air-fuel ratio sensor voltage will rise. After completion, record the current system time T1. Then send the fuel injection quantity coordinated with the air-fuel ratio sensor -12.5% lean instruction for a second preset number of times, and the second preset number of times can also be set as needed. In this embodiment, the value range of the second preset number of times is 430 - 470 times, and in this embodiment, the second preset number of times can be 450 times. Record the current system time T1 when starting to execute the lean instruction. At this time, the oxygen sensor voltage or the air-fuel ratio sensor voltage will drop. When it drops below the first threshold, record the current system time T2, calculate the time difference T2 - T1, terminate sending the lean instruction, and wait for a period of time before executing it again one or more times. In this embodiment, it can wait for 10s and then execute it once again, and calculate the first average value T of these two time differences U , the first threshold can be set as needed. In this embodiment, the first threshold can be set to 0.4V.

[0088] Step 1034: When the first average value T U is greater than 5 seconds, it is determined that the three-way catalyst is in good condition. When the first average value T U is less than or equal to 5 seconds and greater than or equal to 2 seconds, it is determined that the three-way catalyst is in a sub-healthy state. When the first average value T U is less than 2 seconds, it is determined that the three-way catalyst is in a faulty state.

[0089] When the first average value T U is greater than 5 seconds, it is determined that the three-way catalyst of the current vehicle model engine is in good condition. When the first average value T U is less than or equal to 5 seconds and greater than or equal to 2 seconds, it is determined that the three-way catalyst is in a sub-healthy state. At this time, the conversion ability of the three-way catalytic converter is weak. When the first average value T U is less than 2 seconds, it is determined that the three-way catalyst is in a faulty state. At this time, it needs to be repaired in time.

[0090] In another embodiment, as Figure 5 shown, step 103 can further include the following steps:

[0091] Step 1035: Execute the fuel injection quantity coordinated with the air-fuel ratio sensor +12.5% enrichment instruction for a third preset number of times. At this time, the oxygen sensor current or the air-fuel ratio sensor current drops;

[0092] Step 1036: Execute the fourth preset number of times of the fuel injection quantity collaborative air-fuel ratio sensor -12.5% lean addition instruction, and record the current system time T3 at the start of the execution. At this time, the oxygen sensor current or the air-fuel ratio sensor current rises. When it rises above the second threshold, record the current system time T4, and calculate the time difference T4 - T3.

[0093] Step 1037: Repeat a preset number of times, and calculate the second average value T of the time difference I .

[0094] In one implementation, code can be written to execute the third preset number of times of the fuel injection quantity collaborative air-fuel ratio sensor +12.5% rich addition instruction. The third preset number can be set as needed. In this implementation, the value range of the third preset number is 280 - 320 times. In this implementation, the third preset number can be 300 times. During this process, the oxygen sensor current or the air-fuel ratio sensor current will decrease. After completion, record the current system time T3. Then send the fourth preset number of times of the fuel injection quantity collaborative air-fuel ratio sensor -12.5% lean addition instruction. The fourth preset number can also be set as needed. In this implementation, the value range of the fourth preset number is 430 - 470 times. In this implementation, the fourth preset number can be 450 times. Record the current system time T3 at the same time as starting to execute the lean addition instruction. At this time, the oxygen sensor current or the air-fuel ratio sensor current will rise. When it rises above the second threshold, record the current system time T4, calculate the time difference T4 - T3, terminate sending the lean addition instruction, wait for a period of time and then execute it one or more times again. In this implementation, it can wait for 10 s and then execute it 1 time again, and calculate the first average value T of these 2 time differences I , and the second threshold can be set as needed. In this implementation, the second threshold can be set to 0.0 mA.

[0095] Step 1038: When the second average value T I is greater than 5 s, determine that the three-way catalyst is in good condition. When the second average value T I is less than or equal to 5 s and greater than or equal to 2 s, determine that the three-way catalyst is in a sub-healthy state. When the first average value T I is less than 2 s, determine that the three-way catalyst is in a faulty state.

[0096] When the first average value T U is greater than 5 s, determine that the three-way catalyst of the current vehicle model engine is in good condition. When the first average value T U is less than or equal to 5 s and greater than or equal to 2 s, determine that the three-way catalyst is in a sub-healthy state. At this time, the conversion ability of the three-way catalytic converter is weak. When the first average value T U is less than 2 s, determine that the three-way catalyst is in a faulty state. At this time, it needs to be repaired in time.

[0097] In this application, during the test of fuel injection quantity in coordination with the air-fuel ratio sensor, the enriched fuel injection quantity of +12.5% and the lean fuel injection quantity of -12.5% are used to monitor the duration for which the voltage and current of the oxygen sensor or the air-fuel ratio sensor reach the specified range, thereby quickly and efficiently determining the performance of the vehicle's three-way catalytic converter, providing a solid scientific basis for the judgment of whether to repair or replace the three-way catalytic converter, and saving a large amount of time cost for maintenance technicians.

[0098] Embodiment 2:

[0099] As Figure 6 shown, in one implementation of the three-way catalytic converter test device provided in Embodiment 2 of this application, it includes a first judgment module 610, a second judgment module 620, and a processing module 630.

[0100] The first judgment module 610 is used to judge whether the vehicle supports the test of fuel injection quantity in coordination with the air-fuel ratio sensor according to the DID. When the vehicle supports the test of fuel injection quantity in coordination with the air-fuel ratio sensor, the test is started.

[0101] The second judgment module 620 is used to judge whether the current vehicle model supports the voltage judgment method or the current judgment method according to the PID identifier of the oxygen sensor or the air-fuel ratio sensor. If it supports, the voltage judgment method or the current judgment method is used for the test.

[0102] The processing module 630 is used to sequentially execute the fuel injection quantity in coordination with the air-fuel ratio sensor enrichment instruction and the lean instruction a predetermined number of times, and judge the performance of the three-way catalytic converter according to the time difference between the start of executing the fuel injection quantity in coordination with the air-fuel ratio sensor lean instruction and the completion of the fuel injection quantity in coordination with the air-fuel ratio sensor lean instruction.

[0103] Furthermore, as Figure 7 shown, the second judgment module 620 may include:

[0104] The second communication unit 621 is used to establish a communication connection with the engine ECU.

[0105] The voltage judgment unit 622 is used to read the PID identifier, search in combination with the database. If the oxygen sensor or the air-fuel ratio sensor voltage PID is matched, it is determined that the voltage judgment method is supported; otherwise, the voltage judgment method is not supported.

[0106] By reading the PID identifier supported by the data stream through communication with the engine ECU and searching in combination with the database, if the oxygen sensor or the air-fuel ratio sensor voltage PID is matched, it is determined that the voltage judgment method is supported; otherwise, the voltage judgment method is not supported. The PID of each function can be defined independently by manufacturers such as Toyota and Lexus.

[0107] The current judgment unit 623 is used to perform a search in combination with a database when the voltage determination method is not supported. If the current PID of the oxygen sensor or the air-fuel ratio sensor is matched, it is determined that the current determination method is supported; otherwise, the current determination method is not supported.

[0108] By communicating with the engine ECU to read the PID identifiers supported by the data stream, and performing a search in combination with a database. If the current PID of the oxygen sensor or the air-fuel ratio sensor is matched, it is determined that the current determination method is supported; otherwise, the current determination method is not supported.

[0109] Further, as Figure 8 shown, the processing module 630 may include:

[0110] The first enrichment unit 631 is used to execute the first preset number of times the fuel injection quantity collaborative air-fuel ratio sensor +12.5% enrichment instruction. At this time, the voltage of the oxygen sensor or the air-fuel ratio sensor rises.

[0111] The first lean unit 632 is used to execute the second preset number of times the fuel injection quantity collaborative air-fuel ratio sensor -12.5% lean instruction, and record the current system time T1 when starting to execute. At this time, the voltage of the oxygen sensor or the air-fuel ratio sensor drops. When it drops to the first threshold, record the current system time T2, and calculate the time difference T2 - T1.

[0112] The first calculation unit 633 is used to repeat a predetermined number of times to calculate the first average value T of the time difference U 。

[0113] In one embodiment, code can be written to execute the first preset number of times the fuel injection quantity collaborative air-fuel ratio sensor +12.5% enrichment instruction. The first preset number of times can be set as needed. In this embodiment, the value range of the first preset number of times is 280 - 320 times. In this embodiment, the first preset number of times can be 300 times. During this process, the voltage of the oxygen sensor or the air-fuel ratio sensor will rise. Then send the second preset number of times the fuel injection quantity collaborative air-fuel ratio sensor -12.5% lean instruction. The second preset number of times can also be set as needed. In this embodiment, the second preset number of times can be 450 times. Record the current system time T1 when starting to execute the lean instruction. At this time, the voltage of the oxygen sensor or the air-fuel ratio sensor will drop. When it drops to less than the first threshold, record the current system time T2, calculate the time difference T2 - T1, terminate sending the lean instruction, wait for a period of time and then execute it once or multiple times again. In this embodiment, it can wait for 10s and then execute it 1 time again, and calculate the first average value T of the time differences of these 2 times U , the first threshold can be set as needed. In this embodiment, the first threshold can be set to 0.4V.

[0114] The first processing unit 634 is configured to determine that the three-way catalyst is in good condition when the first average value T U is greater than 5 seconds. When the first average value T U is less than or equal to 5 seconds and greater than or equal to 2 seconds, it is determined that the three-way catalyst is in a sub-healthy state. When the first average value T U is less than 2 seconds, it is determined that the three-way catalyst is in a faulty state.

[0115] When the first average value T U is greater than 5 seconds, it is determined that the three-way catalyst of the engine of the current vehicle model is in good condition. When the first average value T U is less than or equal to 5 seconds and greater than or equal to 2 seconds, it is determined that the three-way catalyst is in a sub-healthy state. At this time, the conversion ability of the three-way catalytic converter is weak. When the first average value T U is less than 2 seconds, it is determined that the three-way catalyst is in a faulty state. At this time, it needs to be repaired in time.

[0116] Further, as Figure 9 shown, the processing module 630 may further include:

[0117] The second enrichment unit 635 is configured to execute the fuel injection amount coordinated with the air-fuel ratio sensor +12.5% enrichment instruction for a third preset number of times. At this time, the oxygen sensor current or the air-fuel ratio sensor current decreases.

[0118] The second lean unit 636 is configured to execute the fuel injection amount coordinated with the air-fuel ratio sensor -12.5% lean instruction for a fourth preset number of times, and record the current system time T3 when starting to execute the lean instruction. At this time, the oxygen sensor current or the air-fuel ratio sensor current increases. When it rises to be greater than the second threshold, record the current system time T4, and calculate the time difference T4 - T3.

[0119] The second calculation unit 637 is configured to repeat a predetermined number of times to calculate the second average value T of the time difference I .

[0120] In one embodiment, code can be written to execute the third preset number of times the fuel injection quantity collaborative air-fuel ratio sensor +12.5% enrichment instruction, and the third preset number of times can be set as needed. In this embodiment, the value range of the third preset number of times can be 280 - 320 times. In this embodiment, the third preset number of times is 300 times. During this process, the oxygen sensor current or the air-fuel ratio sensor current will decrease. Then, send the fuel injection quantity collaborative air-fuel ratio sensor -12.5% lean instruction for the fourth preset number of times. At the same time as starting to execute the lean instruction, start recording the current system time T3. The fourth preset number of times can also be set as needed. In this embodiment, the value range of the fourth preset number of times is 430 - 470 times. In this embodiment, the fourth preset number of times can be 450 times. At this time, the oxygen sensor current or the air-fuel ratio sensor current will increase. When it rises to be greater than the second threshold, record the current system time T4, calculate the time difference T4 - T3, terminate sending the lean instruction, and wait for a period of time before executing it one or more times again. In this embodiment, it can wait for 10s and then execute it 1 time again, and calculate the first average value T of these 2 time differences I The second threshold can be set as needed. In this embodiment, the second threshold can be set to 0.0mA.

[0121] The second processing unit 638 is used to when the second average value T I is greater than 5 seconds, determine that the three-way catalyst is in good condition. When the second average value T I is less than or equal to 5 seconds and greater than or equal to 2 seconds, determine that the three-way catalyst is in a sub-healthy state. When the first average value T I is less than 2 seconds, determine that the three-way catalyst is in a faulty state.

[0122] When the first average value T U is greater than 5 seconds, determine that the three-way catalyst of the current vehicle model engine is in good condition. When the first average value T U is less than or equal to 5 seconds and greater than or equal to 2 seconds, determine that the three-way catalyst is in a sub-healthy state. At this time, the conversion ability of the three-way catalytic converter is weak. When the first average value T U is less than 2 seconds, determine that the three-way catalyst is in a faulty state. At this time, it needs to be repaired in time.

[0123] By monitoring the time that the voltage and current of the oxygen sensor or the air-fuel ratio sensor reach the specified range through the enrichment +12.5% and lean -12.5% fuel injection quantities during the fuel injection quantity collaborative air-fuel ratio sensor test process, the performance of the three-way catalytic converter can be quickly and efficiently judged, providing a solid scientific basis for the judgment of whether to repair or replace the three-way catalytic converter, and saving a large amount of time cost for maintenance technicians.

[0124] Furthermore, the first judgment module 610 can include:

[0125] The first communication unit 611 is used to establish a communication connection with the engine ECU;

[0126] The reading unit 612 is used to read the first DID that supports the action test;

[0127] The matching unit 613 is used to perform a search in combination with the database. If the second DID of the EGR valve step position is matched, it is determined to be supported; otherwise, it is not supported.

[0128] By communicating with the engine ECU to read the DID identifier supported by the action test, and performing a search in combination with the database. If the DID for the fuel injection volume coordinated with the air-fuel ratio sensor test is matched, it is determined that the vehicle supports the fuel injection volume coordinated with the air-fuel ratio sensor test; otherwise, it is determined that the vehicle does not support the fuel injection volume coordinated with the air-fuel ratio sensor test. The DID for each function can be independently defined by Toyota and Lexus manufacturers.

[0129] Embodiment III:

[0130] The three-way catalytic converter test device provided in Embodiment III of the present application, in one implementation manner, includes a memory and a processor.

[0131] The memory is used to store programs;

[0132] The processor is used to implement the method in Embodiment I by executing the programs stored in the memory.

[0133] Those skilled in the art can understand that all or part of the functions of the above methods can be implemented in a hardware manner or in a computer program manner. When all or part of the functions in the above embodiments are implemented in a computer program manner, the program can be stored in a computer-readable storage medium. The storage medium can include: read-only memory, random access memory, magnetic disks, optical disks, hard disks, etc. By executing the program on a computer to implement the above functions. For example, storing the program in the memory of the device, when the processor executes the program in the memory, the above all or part of the functions can be implemented. In addition, when all or part of the functions in the above embodiments are implemented in a computer program manner, the program can also be stored in a storage medium such as a server, another computer, magnetic disk, optical disk, flash drive or mobile hard disk, downloaded or copied and saved to the memory of the local device, or the system of the local device is updated. When the processor executes the program in the memory, the above all or part of the functions in the embodiments can be implemented.

[0134] The above uses specific examples to illustrate the present invention, which is only for helping to understand the present invention and is not intended to limit the present invention. For those skilled in the art to which the present invention pertains, several simple deductions, deformations or substitutions can also be made according to the idea of the present invention.

Claims

1. A method for testing a three-way catalytic converter, characterized in that, it includes: Judging whether the vehicle supports the fuel injection volume collaborative air-fuel ratio sensor test according to the decentralized identifier. When the vehicle supports the fuel injection volume collaborative air-fuel ratio sensor test, start the test; Judging whether the current vehicle model supports the voltage determination method or the current determination method according to the PID identifier of the oxygen sensor or the air-fuel ratio sensor. If it supports, perform the test using the voltage determination method or the current determination method; Sequentially execute the fuel injection volume collaborative air-fuel ratio sensor enrichment instruction and lean instruction a predetermined number of times, and judge the performance of the three-way catalytic converter according to the time difference between the start of executing the fuel injection volume collaborative air-fuel ratio sensor lean instruction and the completion of the fuel injection volume collaborative air-fuel ratio sensor lean instruction; The judging whether the current vehicle model supports the voltage determination method or the current determination method according to the PID identifier of the oxygen sensor or the air-fuel ratio sensor includes: Establish a communication connection with the engine ECU; Read the PID identifier and search in combination with the database. If the oxygen sensor or air-fuel ratio sensor voltage PID is matched, it is determined that the voltage determination method is supported, otherwise the voltage determination method is not supported; When the voltage determination method is not supported, search in combination with the database. If the oxygen sensor or air-fuel ratio sensor current PID is matched, it is determined that the current determination method is supported, otherwise the current determination method is not supported; The sequentially executing the fuel injection volume collaborative air-fuel ratio sensor enrichment instruction and lean instruction a predetermined number of times, and judging the performance of the three-way catalytic converter according to the time difference between the start of executing the fuel injection volume collaborative air-fuel ratio sensor lean instruction and the completion of the fuel injection volume collaborative air-fuel ratio sensor lean instruction includes: Execute the fuel injection volume collaborative air-fuel ratio sensor +12.5% enrichment instruction for the first preset number of times, and at this time the oxygen sensor voltage or air-fuel ratio sensor voltage rises; Execute the fuel injection volume collaborative air-fuel ratio sensor -12.5% lean instruction for the second preset number of times, and record the current system time T1 when starting to execute. At this time, the oxygen sensor voltage or air-fuel ratio sensor voltage drops. When it drops to the first threshold, record the current system time T2, and calculate the time difference T2 - T1; Repeat a predetermined number of times and calculate a first average value T of the time difference U ; When the first average value T U is greater than 5 seconds, it is determined that the three-way catalyst is in good condition. When the first average value T U is less than or equal to 5 seconds and greater than or equal to 2 seconds, it is determined that the three-way catalyst is in a sub-healthy state. When the first average value T U is less than 2 seconds, it is determined that the three-way catalyst is in a faulty state; The judging whether the vehicle supports the fuel injection volume collaborative air-fuel ratio sensor test according to the decentralized identifier. When the vehicle supports the fuel injection volume collaborative air-fuel ratio sensor test, start the test includes: Establish a communication connection with the engine ECU; Read the first decentralized identifier that supports the action test; Search in combination with the database. If the second decentralized identifier of the EGR valve step position is matched, it is determined that it is supported, otherwise it is not supported.

2. The method for testing a three-way catalytic converter according to claim 1, characterized in that, The sequentially executing the fuel injection volume collaborative air-fuel ratio sensor enrichment instruction and lean instruction a predetermined number of times, and judging the performance of the three-way catalytic converter according to the time difference between the start of executing the fuel injection volume collaborative air-fuel ratio sensor lean instruction and the completion of the fuel injection volume collaborative air-fuel ratio sensor lean instruction includes: Execute the fuel injection volume collaborative air-fuel ratio sensor +12.5% enrichment instruction for the third preset number of times, and at this time the oxygen sensor current or air-fuel ratio sensor current drops; Execute the fourth preset number of fuel injection quantity collaborative air-fuel ratio sensor -12.5% lean addition commands, and record the current system time T3 at the start of execution. At this time, the oxygen sensor current or the air-fuel ratio sensor current rises. When it rises above the second threshold, record the current system time T4, and calculate the time difference T4 - T3; Repeat a predetermined number of times and calculate a second average value T of the time difference I ; When the second average value T I is greater than 5 seconds, it is determined that the three-way catalyst is in good condition. When the second average value T I is less than or equal to 5 seconds and greater than or equal to 2 seconds, it is determined that the three-way catalyst is in a sub-healthy state. When the first average value T I is less than 2 seconds, it is determined that the three-way catalyst is in a faulty state.

3. A three-way catalytic converter test device, characterized in that, adopts the three-way catalytic converter test method as described in claim 1, including: A first judgment module, configured to judge whether the vehicle supports the fuel injection quantity collaborative air-fuel ratio sensor test according to the decentralized identifier. When the vehicle supports the fuel injection quantity collaborative air-fuel ratio sensor test, start the test; A second judgment module, configured to judge whether the current vehicle model supports the voltage determination method or the current determination method according to the PID identifier of the oxygen sensor or the air-fuel ratio sensor. If it supports, perform the voltage determination method or the current determination method for testing; A processing module, configured to sequentially execute a predetermined number of fuel injection quantity collaborative air-fuel ratio sensor enrichment commands and lean addition commands, and judge the performance of the three-way catalytic converter according to the time difference between the start of executing the fuel injection quantity collaborative air-fuel ratio sensor lean addition command and the completion of the fuel injection quantity collaborative air-fuel ratio sensor lean addition command.

4. The three-way catalytic converter test device as described in claim 3, characterized in that, the second judgment module includes: A second communication unit, configured to establish a communication connection with the engine ECU; A voltage judgment unit, configured to read the PID identifier, search in combination with the database. If the oxygen sensor or the air-fuel ratio sensor voltage PID is matched, it is determined that the voltage determination method is supported, otherwise the voltage determination method is not supported; A current judgment unit, configured to search in combination with the database when the voltage determination method is not supported. If the oxygen sensor or the air-fuel ratio sensor current PID is matched, it is determined that the current determination method is supported, otherwise the current determination method is not supported.

5. The three-way catalytic converter test device as described in claim 3, characterized in that, the processing module includes: A first enrichment unit, configured to execute the first preset number of fuel injection quantity collaborative air-fuel ratio sensor +12.5% enrichment commands. At this time, the oxygen sensor voltage or the air-fuel ratio sensor voltage rises; A first lean addition unit, configured to execute the second preset number of fuel injection quantity collaborative air-fuel ratio sensor -12.5% lean addition commands, and record the current system time T1 at the start of execution. At this time, the oxygen sensor voltage or the air-fuel ratio sensor voltage drops. When it drops to the first threshold, record the current system time T2, and calculate the time difference T2 - T1; A first calculation unit, which is used to calculate a first average value T of the time difference by repeating a predetermined number of times U ; The first processing unit is configured to, when the first average value T U is greater than 5 seconds, determine that the three-way catalyst is in good condition. When the first average value T U is less than or equal to 5 seconds and greater than or equal to 2 seconds, determine that the three-way catalyst is in a sub-healthy state. When the first average value T U is less than 2 seconds, determine that the three-way catalyst is in a faulty state.

6. The three-way catalytic converter test device as described in claim 3, characterized in that, the processing module includes: A second enrichment unit, configured to execute the third preset number of fuel injection quantity collaborative air-fuel ratio sensor +12.5% enrichment commands. At this time, the oxygen sensor current or the air-fuel ratio sensor current drops; A second lean addition unit is configured to execute the fourth preset number of times of the fuel injection quantity coordination air-fuel ratio sensor - 12.5% lean addition instruction, and record the current system time T3 when starting to execute. At this time, the oxygen sensor current or the air-fuel ratio sensor current rises, and when it rises to be greater than the second threshold, record the current system time T4, and calculate the time difference T4 - T3; A second calculation unit, which is used to calculate a second average value T of the time difference by repeating a predetermined number of times I ; A second processing unit, configured to determine that the three-way catalyst is in good condition when the second average value T I is greater than 5 seconds, and determine that the three-way catalyst is in a sub-healthy state when the second average value T I is less than or equal to 5 seconds and greater than or equal to 2 seconds, and determine that the three-way catalyst is in a faulty state when the first average value T I is less than 2 seconds.

7. The three-way catalytic converter test device according to claim 3, wherein, the first judgment module includes: a first communication unit configured to establish a communication connection with the engine ECU; a reading unit configured to read the first decentralized identifier supporting the action test; a matching unit configured to perform a search in combination with a database. If the second decentralized identifier of the EGR valve step position is matched, it is determined to be supported, otherwise it is not supported.

8. A three-way catalytic converter test device, wherein, it includes: a memory configured to store a program; a processor configured to implement the method according to any one of claims 1-2 by executing the program stored in the memory.

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