An exhaust gas flow rate diagnosis method, an engine management device, a medium, and a controller

Abstract

The present application belongs to the technical field of vehicle engineering, and particularly relates to a waste gas flow diagnosis method, an engine management device, a medium and a controller; on the basis of an exhaust gas recirculation (EGR) cooling water path, an EGR bypass branch is added; by cutting off the medium circulation of the EGR cooler part and maintaining the medium circulation of the remaining part through the bypass branch, a heat exchange layout for fault diagnosis is constructed; based on the temperature rise performance of the EGR cooler in the detection process, the diagnosis of low flow faults and high flow faults can be realized respectively, and it is particularly suitable to be implemented in combination with the self-checking process during the engine warm-up process; during this period, it is not necessary to collect EGR temperature sensor data, which is conducive to reducing the integration difficulty of high-pressure EGR parts; and it has a higher detection rate and a better monitoring frequency IUPR (In Use Performance Ratio) for the above faults; in addition, good results can also be achieved for engines using Atkinson cycle combined with high-pressure EGR technology.

Description

Technical Field

[0001] This invention belongs to the field of vehicle engineering technology, and particularly relates to an exhaust gas flow diagnosis method, an engine management device, a medium, and a controller. Background Technology

[0002] Exhaust Gas Recirculation (EGR) technology can effectively reduce fuel consumption and NOx emissions; such as Figure 1 As shown, this is a common air-side structure of an EGR system. After the high-temperature EGR exhaust gas is drawn out from the engine exhaust pipe, it flows sequentially through the EGR cooler, EGR temperature sensor, and EGR valve before entering the engine intake pipe or intake manifold. Then, the EGR exhaust gas and fresh air merge and flow into the engine for combustion.

[0003] Typically, an EGR temperature sensor monitors the EGR exhaust gas temperature, while an EGR differential pressure sensor measures the pressure difference across the EGR valve and calculates the EGR exhaust gas flow rate. However, in diagnosing excessively low or high EGR flow rates, the EGR cooler's heat dissipation capacity, the coolant temperature in the EGR cooling water circuit, and the coolant flow rate directly affect the cooled EGR exhaust gas temperature, thus influencing the temperature rise of the EGR temperature sensor. In situations such as rapid vehicle acceleration, excessively low coolant temperature, or increased coolant pump speed leading to increased coolant flow, even with increased EGR exhaust gas flow, the temperature rise of the EGR temperature sensor may not be significant, making it impossible to obtain appropriate temperature rise or drop for EGR flow rate diagnosis. Summary of the Invention

[0004] This invention discloses a method for diagnosing exhaust gas flow rate, including a first detection and treatment step and a second diagnosis and confirmation step; wherein the first detection and treatment step includes a first detection step and a first second treatment step.

[0005] Specifically, the first detection step acquires operating condition information and makes a judgment based on preset diagnostic preconditions. If the diagnostic preconditions are met, the first and second handling steps are executed. In the first and second handling steps, at the first moment M1, the flow channel of the first coolant in the first heat exchange circuit where the exhaust gas recirculation (EGR) cooler is located is cut off, and the remaining part of the first coolant enters the second heat exchange circuit through the bypass channel of the EGR cooler. The first and second handling steps record the initial temperature vector VT at the first moment M1. The initial temperature vector VT includes the initial value of the first temperature TA and the initial value of the second temperature TB. The first temperature TA is collected from the first heat exchange circuit, and the second temperature TB is collected from the second heat exchange circuit. The exhaust gas recirculation (EGR) valve is adjusted to change the heat transferred to the EGR cooler. The EGR valve is located between the air side of the EGR cooler and the engine intake unit and is used to control the flow or shut-off of the EGR exhaust gas.

[0006] Furthermore, the second diagnostic and confirmation step includes a second first diagnostic step and a second second confirmation step; the second first diagnostic step scans or repeatedly acquires the first temperature TA at preset time intervals; the second first diagnostic step acquires the first temperature rise ΔT1 of the first temperature TA, where the first temperature rise ΔT1 is the increase in the first temperature TA; the second second confirmation step compares the relationship between the first temperature rise ΔT1 and the preset temperature rise range, judges the fault state, confirms and executes a reset operation, whereby the reset operation opens the flow channel in the first heat exchange circuit and closes the bypass channel.

[0007] Specifically, its diagnostic prerequisites include a first prerequisite and a second prerequisite. When either the first or second prerequisite is met, the diagnostic prerequisites are met, and when the diagnostic prerequisites are met, no predefined fault markers should exist. The first prerequisite includes at least one of the following conditions: a first temperature TA is less than threshold L1, a second temperature TB is less than threshold L2, the engine running time after starting is greater than threshold L3, the engine speed is greater than threshold L4, and the EGR valve is closed. Thresholds L1, L2, L3, and L4 are calibrated values, which are obtained through testing or experimentation. The second prerequisite includes at least one of the following conditions: a first temperature TA is less than threshold H1, a second temperature TB is less than threshold H2, the engine running time after starting is greater than threshold H3, the engine speed is greater than threshold H4, and the EGR valve is closed.

[0008] Furthermore, if the first prerequisite and / or the second prerequisite are met, then the following fault markers must not exist: EGR coolant temperature sensor fault, engine coolant temperature sensor fault, EGR low flow fault, EGR high flow fault, engine coolant temperature sensor related fault, EGR valve related fault, EGR cooling branch solenoid valve drive stage fault, and EGR bypass branch solenoid valve drive stage fault.

[0009] Specifically, its second heat exchange circuit includes a bypass channel, a second valve, an engine radiator, a coolant pump, and a cooling water circuit for the engine block; its first coolant is exhaust gas recirculation (EGR) coolant; its engine intake unit includes an intake pipe or an intake manifold; and its second temperature TB can be collected from any of the following locations: engine cylinder head water temperature sensor, cylinder block water temperature sensor, engine coolant outlet water temperature sensor, engine coolant inlet water temperature sensor, and radiator outlet water temperature sensor.

[0010] Furthermore, for low flow monitoring, the diagnostic method may also include a flow integration step and a first temperature rise discrimination step. The flow integration step detects the target flow integral A1 until it exceeds the first target flow integral threshold TIF. Here, the (EGR) target flow is defined as the target flow of the EGR exhaust gas demand calculated based on real-time engine speed, load, and mathematical modeling. If the EGR valve is open and the EGR target flow F is less than or equal to the first target flow threshold TF, the target flow integral A1 is cleared to zero. Otherwise, the EGR target flow F continues to be integrated. During this process, if the first temperature TA is greater than or equal to the first discrimination temperature threshold TTL, a reset operation is performed, and the first detection step is re-entered. Additionally, if the target flow integral A1 is greater than the first target flow integral threshold TIF, the first temperature rise discrimination step is entered.

[0011] The first temperature rise determination step records the current value of the first temperature TA and calculates the first temperature rise ΔT1, which is the difference between the current value of the first temperature TA and its initial value. The second temperature TB is recorded and the second temperature rise ΔT2 is calculated, which is the difference between the current value of the second temperature TB and its initial value. Both ΔT1 and ΔT2 are greater than zero. If ΔT2 is less than the first engine temperature rise threshold TL, the flow integration step is restarted. If ΔT1 is less than the low flow temperature rise threshold, a low flow fault in the EGR is confirmed; otherwise, the low flow fault does not exist.

[0012] On the other hand, high flow faults can also be monitored. Specifically, the method may also include a flow timing step and a second temperature rise discrimination step. The flow timing step detects the timer time Ti until the timer time Ti is greater than the second timer threshold TT. The timer time Ti is defined as a time accumulator for meeting the high flow diagnostic precondition, starting from 0. If the high flow timing condition is not met, the timer time Ti is cleared to zero. Otherwise, the timer time Ti starts counting from zero. During this period, if the first temperature TA is greater than or equal to the second discrimination temperature threshold TTH, a reset operation is performed and the first detection step is re-entered. In addition, if the timer time Ti is greater than the second timer threshold TT, the second temperature rise discrimination step is entered.

[0013] The second temperature rise determination step records the current value of the first temperature TA and calculates the third temperature rise △T3, which is the difference between the current value of the first temperature TA and the initial value of the first temperature; records the current value of the second temperature TB and calculates the fourth temperature rise △T4, which is the difference between the current value of the second temperature TB and the initial value of the second temperature TB; and further obtains the cooling water circuit temperature deviation △T5, which is equal to the difference between the current value of the first temperature TA and the current value of the second temperature; wherein △T3 and △T4 are both greater than zero; at this time, if the fourth temperature rise △T4 is greater than or equal to the second engine temperature rise threshold TH, the flow timing step is restarted; in addition, if △T3 is greater than the preset threshold and △T5 is greater than the preset threshold, it is confirmed that there is a high flow fault in EGR; otherwise, the high flow fault does not exist.

[0014] To improve diagnostic performance, the above methods can be implemented during the engine warm-up phase. Since the flow of coolant in the EGR cooler is restricted, the temperature rise after being heated by the EGR exhaust gas will be more significant, making it easier to detect pipeline abnormalities and improve the monitoring frequency IUPR (In Use Performance Ratio).

[0015] Specifically, the above diagnostic process can be performed when the time from the engine start time MS to the first moment M1 is less than the preset warm-up time threshold TX.

[0016] This invention also discloses an engine management device, including a first detection and handling unit and a second diagnosis and confirmation unit; wherein the first detection and handling unit includes a first detection unit and a first second handling unit.

[0017] Specifically, the first detection unit acquires operating condition information and makes a judgment based on preset diagnostic preconditions. If the diagnostic preconditions are met, the information is handed over to the first and second processing units for processing. The first and second processing units cut off the flow channel of the first coolant in the first heat exchange circuit where the exhaust gas recirculation (EGR) cooler is located at the first moment M1. The remaining part of the first coolant enters the second heat exchange circuit through the bypass channel of the EGR cooler. The first and second processing units record the initial temperature vector VT at the first moment M1. The initial temperature vector VT includes the initial value of the first temperature TA and the initial value of the second temperature TB. The first temperature TA is collected from the first heat exchange circuit, and the second temperature TB is collected from the second heat exchange circuit. The exhaust gas recirculation (EGR) valve is adjusted to change the heat transferred to the EGR cooler. The EGR valve is located between the air side of the EGR cooler and the engine intake unit and is used to control the flow or shut-off of the EGR exhaust gas.

[0018] The second diagnostic and confirmation unit includes a second first diagnostic unit and a second second confirmation unit. The second first diagnostic unit scans or repeatedly acquires the first temperature TA at preset time intervals. The second first diagnostic unit acquires the first temperature rise ΔT1 of the first temperature TA, which is the increase value of the first temperature TA. The second second confirmation unit compares the relationship between the first temperature rise ΔT1 and the preset temperature rise range, judges the fault state, confirms and executes a reset operation. The reset operation opens the flow channel in the first heat exchange circuit and closes the bypass channel.

[0019] Specifically, its diagnostic prerequisites include a first prerequisite and a second prerequisite. When the first prerequisite or the second prerequisite is met, its diagnostic prerequisites are met. And when the diagnostic prerequisites are met, there must be no predefined fault markers.

[0020] The first prerequisite includes at least one of the following conditions: the first temperature TA is less than the threshold L1, the second temperature TB is less than the threshold L2, the engine running time after starting is greater than the threshold L3, the engine speed is greater than the threshold L4, and the EGR valve is closed; the thresholds L1, L2, L3, and L4 are all calibrated values, which are obtained through tests or experiments.

[0021] On the other hand, the second prerequisite includes at least one of the following conditions: the first temperature TA is less than the threshold H1, the second temperature TB is less than the threshold H2, the engine running time after starting is greater than the threshold H3, the engine speed is greater than the threshold H4, and the EGR valve is closed.

[0022] Accordingly, if the first prerequisite is met, the following fault markers must not exist: EGR coolant temperature sensor fault, engine coolant temperature sensor fault, EGR low flow fault, EGR high flow fault, engine coolant temperature sensor related fault, EGR valve related fault, EGR cooling branch solenoid valve drive stage fault, and EGR bypass branch solenoid valve drive stage fault.

[0023] On the other hand, if the second precondition is met, there must also be no fault markers corresponding to any of the above faults.

[0024] Specifically, the second heat exchange circuit may include a bypass channel, a second valve, an engine radiator, a coolant pump, and a cooling water circuit in the engine body; the first coolant is exhaust gas recirculation (EGR) coolant; and the engine intake unit includes an intake pipe or an intake manifold.

[0025] The second temperature TB can be collected from any of the following locations: engine cylinder head water temperature sensor, cylinder block water temperature sensor, engine coolant outlet water temperature sensor, engine coolant inlet water temperature sensor, radiator outlet water temperature sensor; in addition, the time between the first moment M1 and the engine start moment MS can be less than the preset warm-up time threshold TX, where TX is a positive integer.

[0026] Specifically, the device may further include a flow integration unit and a first temperature rise discrimination unit; the flow integration unit detects the target flow integration A1 until the target flow integration A1 is greater than the first target flow integration threshold TIF; wherein, if the EGR valve is open and the EGR target flow F is less than or equal to the first target flow threshold TF, the target flow integration A1 is cleared to zero; otherwise, the EGR target flow F continues to be integrated; during this period, if the first temperature TA is greater than or equal to the first discrimination temperature threshold TTL, a reset operation is performed and the device is reprocessed by the first detection unit; furthermore, if the target flow integration A1 is greater than the first target flow integration threshold TIF, the device is processed by the first temperature rise discrimination unit.

[0027] The first temperature rise discrimination unit records the current value of the first temperature TA and calculates the first temperature rise ΔT1, which is the difference between the current value of the first temperature TA and its initial value. It also records the current value of the second temperature TB and calculates the second temperature rise ΔT2, which is the difference between the current value of the second temperature and the initial value of the first temperature TB. Both ΔT1 and ΔT2 are greater than zero. If ΔT2 is less than the first engine temperature rise threshold TL, the process is reprocessed by the flow integration unit. Furthermore, if ΔT1 is less than the low flow temperature rise threshold, a low flow fault in the EGR is confirmed; otherwise, the low flow fault does not exist.

[0028] On the other hand, the device may also include a flow timing unit and a second temperature rise discrimination unit; the flow timing unit detects the timer time Ti until the timer time Ti is greater than the second timer threshold TT; wherein, if the high flow timing condition is not met, the timer time Ti is reset to zero; otherwise, the timer time Ti starts counting from zero; during this period, if the first temperature TA is greater than or equal to the second discrimination temperature threshold TTH, a reset operation is performed and the device is reprocessed by the first detection unit; furthermore, if the timer time Ti is greater than the second timer threshold TT, the device is processed by the second temperature rise discrimination unit.

[0029] The second temperature rise discrimination unit records the current value of the first temperature TA and calculates the third temperature rise △T3, which is the difference between the current value of the first temperature TA and the initial value of the first temperature; it records the current value of the second temperature TB and calculates the fourth temperature rise △T4, which is the difference between the current value of the second temperature TB and the initial value of the second temperature TB; then it obtains the cooling water circuit temperature deviation △T5, which is equal to the difference between the current value of the first temperature TA and the current value of the second temperature; where △T3 and △T4 are both greater than zero; at this time, if the fourth temperature rise △T4 is greater than or equal to the second engine temperature rise threshold TH, it is reprocessed by the flow timing unit; in addition, if △T3 is greater than the preset threshold and △T5 is greater than the preset threshold, it is confirmed that there is a high flow fault in EGR; otherwise, the high flow fault does not exist.

[0030] Furthermore, embodiments of the present invention also disclose a computer storage medium, including a storage medium body for storing a computer program; when the computer program is executed by a microprocessor, it implements any of the above-mentioned exhaust gas flow diagnosis methods; a controller (901) is also disclosed, including any of the above-mentioned engine management devices; and / or any computer storage medium; its physical process adopts the same inventive concept as the above-mentioned methods and devices, and will not be described again here.

[0031] In summary, the method and product of this invention add an EGR bypass branch to the EGR cooling water circuit; by cutting off the medium circulation in the EGR cooler section and maintaining the medium circulation in the remaining section through the bypass branch, a heat exchange layout for fault diagnosis is constructed; based on the temperature rise performance of the EGR cooler during the detection process, low-flow and high-flow faults can be diagnosed separately, which is particularly suitable for implementation in conjunction with the self-test process during engine warm-up; during this process, there is no need to collect EGR temperature sensor data, which helps to reduce the integration difficulty of high-pressure EGR components; and it has a higher detection rate and a better monitoring frequency IUPR for the above-mentioned faults; in addition, it can also achieve good results for engines using Atkinson cycle combined with high-pressure EGR technology.

[0032] It should be noted that the terms "first," "second," and similar terms used in this article are merely for describing the constituent elements of the technical solution and do not constitute a limitation on the technical solution, nor should they be interpreted as an indication or implication of the importance of the corresponding elements; elements with terms such as "first," "second," or similar terms indicate that at least one of the elements is included in the corresponding technical solution. Attached Figure Description

[0033] To more clearly illustrate the technical solution of the present invention and facilitate a further understanding of its technical effects, features, and objectives, the present invention will be described in detail below with reference to the accompanying drawings. The drawings constitute an essential part of the specification and are used together with Embodiment 1 of the present invention to illustrate the technical solution of the present invention, but do not constitute a limitation on the present invention.

[0034] The same reference numerals in the attached diagrams represent the same parts, specifically:

[0035] Figure 1 This is a schematic diagram of the gas-side structure of the EGR system in the relevant technologies and embodiments of the present invention.

[0036] Figure 2 This is a schematic diagram of the cooling water circuit of an EGR system in related technologies.

[0037] Figure 3 This is a schematic diagram of the hardware structure of the EGR coolant temperature rise monitoring system in an embodiment of the present invention.

[0038] Figure 4 This is a schematic diagram of a low flow rate diagnosis method according to an embodiment of the present invention.

[0039] Figure 5 The parameter curves for low-flow diagnosis are shown in the embodiments of the present invention.

[0040] Figure 6 This is a schematic diagram of a high-flow-rate diagnostic method according to an embodiment of the present invention.

[0041] Figure 7 The corresponding parameter curves for high flow rate diagnosis are shown in the embodiments of the present invention.

[0042] Figure 8 This is a schematic diagram of the structural composition of an embodiment of the method of the present invention.

[0043] Figure 9 This is a schematic diagram of the structural composition of the first detection and treatment step in an embodiment of the method of the present invention.

[0044] Figure 10 This is a schematic diagram of the structural components of the second diagnostic and confirmation step in an embodiment of the method of the present invention.

[0045] Figure 11 This is a schematic diagram of the structural composition of an embodiment of the engine management device of the present invention.

[0046] Figure 12 This is a schematic diagram of the composition of the first detection and processing unit in an embodiment of the engine management device of the present invention.

[0047] Figure 13 This is a schematic diagram of the composition of the second diagnostic and confirmation unit in an embodiment of the engine management device of the present invention.

[0048] Figure 14 This is a layout diagram of an embodiment of the product of the present invention. Figure 1 .

[0049] Figure 15 This is a layout diagram of an embodiment of the product of the present invention. Figure 2 .

[0050] Figure 16 This is a layout diagram of an embodiment of the product of the present invention. Figure 3 .

[0051] in:

[0052] 100 - First detection and handling steps;

[0053] 110 - First detection step;

[0054] 120 - First and second treatment steps;

[0055] 199 - Operating Condition Information;

[0056] 200 - Second diagnostic and confirmation step;

[0057] 201 - Diagnosis begins;

[0058] 209 - Diagnosis complete;

[0059] 210 - Second diagnostic step;

[0060] 211-EGR temperature comparison;

[0061] 213 - Traffic Integral Steps;

[0062] 214 - First temperature rise determination step;

[0063] 215 - Flow timing steps;

[0064] 216 - Second temperature rise determination step;

[0065] 219 - Temperature rise acquisition;

[0066] 220 - Second confirmation step;

[0067] 221 - Low flow fault confirmed;

[0068] 222 - Reset operation;

[0069] 229 - High flow rate fault confirmed;

[0070] 231-EGR valve open flag position;

[0071] 232 - Low flow diagnostic prerequisites met flag;

[0072] 233 - Initial temperature sampling completed;

[0073] 234 - Target flow integral satisfaction flag;

[0074] 235 - High flow rate timing condition meets the flag;

[0075] 236 - High flow rate diagnostic prerequisites are met (marker).

[0076] 237 - Timer completion flag;

[0077] 261 - Low flow fault troubleshooting or testing completed;

[0078] 269 ​​- High flow rate fault troubleshooting or testing completed;

[0079] 299 - Status Confirmation and Related Handling;

[0080] 700 - Heat exchange structure;

[0081] 710-EGR system air-side structure;

[0082] 711 - High-temperature exhaust gas;

[0083] 712 - Engine exhaust pipe;

[0084] 713 - Airflow passing through the EGR valve;

[0085] 714 - Engine intake unit, including engine intake piping or intake manifold;

[0086] 715 - Low-temperature exhaust gas after cooling;

[0087] 716-EGR valve;

[0088] 717-EGR differential pressure sensor;

[0089] 718-EGR temperature sensor;

[0090] 719-EGR cooler air side;

[0091] 720-EGR cooler water side;

[0092] 721 - Cooling water pump;

[0093] 722 - Engine radiator;

[0094] 723 - Fan;

[0095] 724-EGR cooler outlet;

[0096] 726 - The outlet of the cooling water passage of the engine block;

[0097] 727 - Engine coolant temperature sensor;

[0098] 728 - Cooling water system of the engine block;

[0099] 730-EGR cooler temperature sensor;

[0100] 732-EGR cooler inlet;

[0101] 734 - First Valve;

[0102] 736 - Bypass Lane;

[0103] 738 - Second valve;

[0104] 900 - Vehicles;

[0105] 901 - Controller;

[0106] 903 - Computer storage media;

[0107] 909 - Engine Management Device. Detailed Implementation

[0108] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Of course, the specific embodiments described below are merely illustrative of the technical solutions of the present invention, and not intended to limit the invention. Furthermore, the parts described in the embodiments or drawings are merely illustrative examples of relevant parts of the present invention, and not the entirety of the invention.

[0109] like Figure 3 , Figure 4 , Figure 8 , Figure 9The exhaust gas flow diagnosis method shown includes a first detection and treatment step 100 and a second diagnosis and confirmation step 200. The first detection and treatment step 100 includes a first detection step 110 and a first second treatment step 120. The first detection step 110 acquires operating condition information 199 and makes a judgment based on preset diagnostic preconditions. If the diagnostic preconditions are met, the first second treatment step 120 is executed. The first second treatment step 120 cuts off the flow channel of the first coolant in the first heat exchange circuit where the exhaust gas recirculation EGR cooler 709 is located at a first moment M1. The remaining portion enters the second heat exchange circuit through the bypass channel 736 of the EGR cooler 709; the first and second processing steps 120 record the initial temperature vector VT at the first moment M1; the initial temperature vector VT includes the initial value of the first temperature TA and the initial value of the second temperature TB; the first temperature TA is collected from the first heat exchange circuit, and the second temperature TB is collected from the second heat exchange circuit; the exhaust gas recirculation EGR valve 716 is adjusted to change the heat transferred to the EGR cooler 709. The EGR valve 716 is located between the air side 719 of the EGR cooler and the engine intake unit 714 and is used to control the flow or shut-off of EGR exhaust gas.

[0110] Specifically, such as Figure 10 As shown, the second diagnosis and confirmation step 200 includes a second diagnosis step 210 and a second confirmation step 220; the second diagnosis step 210 scans or repeatedly acquires the first temperature TA at preset time intervals; the second diagnosis step 210 acquires the first temperature rise ΔT1 of the first temperature TA, where the first temperature rise ΔT1 is the increase value of the first temperature TA; the second confirmation step 220 compares the relationship between the first temperature rise ΔT1 and the preset temperature rise range, judges the fault state, confirms and executes a reset operation 222, whereby the reset operation 222 opens the flow channel in the first heat exchange circuit and closes the bypass channel 736.

[0111] like Figure 4 , Figure 5 As shown, the diagnostic prerequisites include a first prerequisite and a second prerequisite. When either the first or second prerequisite is met, the diagnostic prerequisites are met, and when the diagnostic prerequisites are met, no predefined fault markers shall exist.

[0112] Specifically, the first prerequisite includes at least one of the following conditions: the first temperature TA is less than the threshold L1, the second temperature TB is less than the threshold L2, the engine running time after starting is greater than the threshold L3, the engine speed is greater than the threshold L4, and the EGR valve 716 is closed; the thresholds L1, L2, L3, and L4 are all calibrated values, which are obtained through tests or experiments.

[0113] On the other hand, the second prerequisite includes at least one of the following conditions: the first temperature TA is less than the threshold H1, the second temperature TB is less than the threshold H2, the engine running time after starting is greater than the threshold H3, the engine speed is greater than the threshold H4, and the EGR valve 716 is closed.

[0114] Specifically, if the first prerequisite is met, then the following fault markers must not exist: EGR coolant temperature sensor 730 fault, engine coolant temperature sensor 727 fault, EGR low flow fault, EGR high flow fault, engine coolant temperature sensor related fault, EGR valve related fault, EGR cooling branch solenoid valve drive stage fault, and EGR bypass branch solenoid valve drive stage fault.

[0115] On the other hand, if the second precondition is met, there must also be no fault markers corresponding to any of the above faults.

[0116] Furthermore, such as Figure 1 , Figure 3 As shown, the second heat exchange circuit includes a bypass channel 736, a second valve 738, an engine radiator 722, a coolant pump 721, and a cooling water passage 728 for the engine block; the first coolant is exhaust gas recirculation (EGR) coolant; the engine intake unit 714 includes an intake pipe or an intake manifold; in addition, the second temperature TB can be collected from any of the following locations: engine cylinder head water temperature sensor, cylinder block water temperature sensor, engine coolant outlet water temperature sensor, engine coolant inlet water temperature sensor, and radiator outlet water temperature sensor.

[0117] like Figure 4 As shown, the method of the present invention may further include a flow integration step 213 and a first temperature rise discrimination step 214; the flow integration step 213 detects the target flow integration A1 until the target flow integration A1 is greater than the first target flow integration threshold TIF; wherein, if the EGR valve 716 is open and the EGR target flow F is less than or equal to the first target flow threshold TF, then the target flow integration A1 is cleared to zero; otherwise, the integration of the EGR target flow F continues; during this period, if the first temperature TA is greater than or equal to the first discrimination temperature threshold TTL, then a reset operation 222 is performed and the process re-enters the following steps. Figure 9 The first detection step 110 is shown; in addition, if the target flow integral A1 is greater than the first target flow integral threshold TIF, then the first temperature rise discrimination step 214 is entered.

[0118] In the first temperature rise determination step 214, the current value of the first temperature TA is recorded and the first temperature rise △T1 is calculated. The first temperature rise △T1 is the difference between the current value of the first temperature TA and the initial value of the first temperature TA. The current value of the second temperature TB is recorded and the second temperature rise △T2 is calculated. The second temperature rise △T2 is the difference between the current value of the second temperature and the initial value of the second temperature TB. Both △T1 and △T2 are greater than zero. If △T2 is less than the first engine temperature rise threshold TL, the flow integration step 213 is restarted. In addition, if △T1 is less than the low flow temperature rise threshold, a low flow fault in the EGR is confirmed. Otherwise, the low flow fault does not exist.

[0119] like Figure 6 As shown, the method of the present invention may further include a flow timing step 215 and a second temperature rise discrimination step 216; the flow timing step 215 detects the timer time Ti until the timer time Ti is greater than the second timer threshold TT; wherein, if the high flow timing condition is not met, the timer time Ti is cleared to zero; otherwise, the timer time Ti starts timing from zero; during this period, if the first temperature TA is greater than or equal to the second discrimination temperature threshold TTH, a reset operation 222 is performed and the first detection step 110 is re-entered; in addition, if the timer time Ti is greater than the second timer threshold TT, the second temperature rise discrimination step 216 is entered.

[0120] Specifically, in the second temperature rise determination step 216, the current value of the first temperature TA is recorded and the third temperature rise △T3 is calculated, where △T3 is the difference between the current value of the first temperature TA and the initial value of the first temperature; the current value of the second temperature TB is recorded and the fourth temperature rise △T4 is calculated, where △T4 is the difference between the current value of the second temperature TB and the initial value of the second temperature TB; then, the cooling water circuit temperature deviation △T5 is obtained, which is equal to the difference between the current value of the first temperature TA and the current value of the second temperature; where △T3 and △T4 are both greater than zero; at this time, if the fourth temperature rise △T4 is greater than or equal to the second engine temperature rise threshold TH, then the flow timing step 215 is re-entered; in addition, if △T3 is greater than the preset threshold and △T5 is greater than the preset threshold, then a high flow fault in the EGR is confirmed; otherwise, the high flow fault does not exist.

[0121] To improve the diagnostic results, the first moment M1 can be selected to be less than the preset warm-up time threshold TX, where TX is a positive integer. At this time, the temperature rise of the coolant in the EGR cooler is obvious, and the distinction between normal and faulty pipelines is high, which is conducive to improving the IUPR rate of diagnosis.

[0122] like Figures 11 to 13 and Figures 14 to 16The engine management device 909 shown includes a first detection and processing unit 910 and a second diagnosis and confirmation unit 920; wherein, the first detection and processing unit 910 includes a first detection unit 911 and a first processing unit 912.

[0123] Specifically, the first detection unit 911 acquires operating condition information 199 and makes a judgment based on preset diagnostic preconditions. If the diagnostic preconditions are met, the information is handed over to the first second processing unit 912 for processing. The first second processing unit 912 cuts off the flow channel of the first coolant in the first heat exchange circuit where the exhaust gas recirculation (EGR) cooler 709 is located at the first moment M1. The remaining portion of the first coolant enters the second heat exchange circuit through the bypass channel 736 of the EGR cooler 709. The first second processing unit 912 records the initial temperature vector VT at the first moment M1. The initial temperature vector VT includes the initial value of the first temperature TA and the initial value of the second temperature TB. The first temperature TA can be collected from the first heat exchange circuit, and the second temperature TB can be collected from the second heat exchange circuit. Figure 1 , Figure 3 As shown, the exhaust gas recirculation (EGR) valve 716 is adjusted to change the amount of heat transferred to the EGR cooler 709. The EGR valve 716 is located between the air side of the EGR cooler 719 and the engine intake unit 714 and is used to control the flow or shut-off of EGR exhaust gas.

[0124] Among them, such as Figure 13 As shown, the second diagnostic and confirmation unit 920 includes a second diagnostic unit 921 and a second confirmation unit 922; the second diagnostic unit 921 scans or repeatedly acquires the first temperature TA at preset time intervals; the second diagnostic unit 921 acquires the first temperature rise ΔT1 of the first temperature TA, where the first temperature rise ΔT1 is the increase in the first temperature TA; the second confirmation unit 922 compares the relationship between the first temperature rise ΔT1 and the preset temperature rise range, judges the fault state, confirms and executes a reset operation 222, whereby the reset operation 222 opens the flow channel in the first heat exchange circuit and closes the bypass channel 736.

[0125] Furthermore, such as Figures 11 to 16 The engine management device 909 shown includes diagnostic prerequisites, which include a first prerequisite and a second prerequisite. When the first prerequisite or the second prerequisite is met, the diagnostic prerequisite is met, and when the diagnostic prerequisite is met, there must be no predefined fault marker.

[0126] The first prerequisite includes at least one of the following conditions: the first temperature TA is less than the threshold L1, the second temperature TB is less than the threshold L2, the engine running time after starting is greater than the threshold L3, the engine speed is greater than the threshold L4, and the EGR valve 716 is closed; the thresholds L1, L2, L3, and L4 are all calibrated values, which are obtained through tests or experiments.

[0127] On the other hand, the second prerequisite includes at least one of the following conditions: the first temperature TA is less than the threshold H1, the second temperature TB is less than the threshold H2, the engine running time after starting is greater than the threshold H3, the engine speed is greater than the threshold H4, and the EGR valve 716 is closed.

[0128] Furthermore, if the first prerequisite is met, then the following fault markers must not exist: EGR coolant temperature sensor 730 fault, engine coolant temperature sensor 727 fault, EGR low flow fault, EGR high flow fault, engine coolant temperature sensor related fault, EGR valve related fault, EGR cooling branch solenoid valve drive stage fault, and EGR bypass branch solenoid valve drive stage fault.

[0129] Furthermore, if the second prerequisite is met, there must also be no fault markers corresponding to any of the above faults.

[0130] Specifically, such as Figure 3 As shown, the second heat exchange circuit includes a bypass channel 736, a second valve 738, an engine radiator 722, a cooling water pump 721, and a cooling water passage 728 for the engine body; the first coolant is exhaust gas recirculation (EGR) coolant.

[0131] In addition, such as Figure 1 The engine intake unit 714 shown includes an intake pipe or an intake manifold; the second temperature TB can be collected from any of the following locations: engine cylinder head water temperature sensor, cylinder block water temperature sensor, engine coolant outlet water temperature sensor, engine coolant inlet water temperature sensor, radiator outlet water temperature sensor; wherein, the time between the first moment M1 and the engine start moment MS is less than the preset warm-up time threshold TX, and TX is a positive integer.

[0132] like Figure 4 , Figure 5As shown, this embodiment may further include a flow integration unit and a first temperature rise discrimination unit; the flow integration unit detects the target flow integration A1 until the target flow integration A1 is greater than the first target flow integration threshold TIF; wherein, if the EGR valve 716 is open and the EGR target flow F is less than or equal to the first target flow threshold TF, the target flow integration A1 is cleared to zero; otherwise, the EGR target flow F continues to be integrated; during this period, if the first temperature TA is greater than or equal to the first discrimination temperature threshold TTL, a reset operation 222 is performed and the data is reprocessed by the first detection unit 911; in addition, if the target flow integration A1 is greater than the first target flow integration threshold TIF, the data is processed by the first temperature rise discrimination unit.

[0133] The first temperature rise discrimination unit records the current value of the first temperature TA and calculates the first temperature rise ΔT1, which is the difference between the current value of the first temperature TA and its initial value. It also records the current value of the second temperature TB and calculates the second temperature rise ΔT2, which is the difference between the current value of the second temperature TB and its initial value. Both ΔT1 and ΔT2 are greater than zero. If ΔT2 is less than the first engine temperature rise threshold TL, the process is re-handled by the flow integration unit. Furthermore, if ΔT1 is less than the low flow temperature rise threshold, a low flow fault in the EGR is confirmed; otherwise, the low flow fault does not exist.

[0134] like Figure 6 , Figure 7 and Figures 11 to 16 As shown, the engine management device 909 may further include a flow timing unit and a second temperature rise discrimination unit; the flow timing unit detects the timer time Ti until the timer time Ti is greater than the second timer threshold TT; wherein, if the high flow timing condition is not met, the timer time Ti is reset to zero; otherwise, the timer time Ti starts counting from zero; during this period, if the first temperature TA is greater than or equal to the second discrimination temperature threshold TTH, a reset operation 222 is performed and the data is reprocessed by the first detection unit 911; in addition, if the timer time Ti is greater than the second timer threshold TT, the data is processed by the second temperature rise discrimination unit.

[0135] The second temperature rise discrimination unit records the current value of the first temperature TA and calculates the third temperature rise △T3, which is the difference between the current value of the first temperature TA and the initial value of the first temperature. It also records the current value of the second temperature TB and calculates the fourth temperature rise △T4, which is the difference between the current value of the second temperature TB and the initial value of the second temperature TB. Furthermore, it obtains the cooling water circuit temperature deviation △T5, which is equal to the difference between the current value of the first temperature TA and the current value of the second temperature. Both △T3 and △T4 are greater than zero. If the fourth temperature rise △T4 is greater than or equal to the second engine temperature rise threshold TH, the process is re-handled by the flow timing unit. Additionally, if △T3 is greater than a preset threshold and △T5 is greater than a preset threshold, a high flow fault in the EGR is confirmed; otherwise, the high flow fault does not exist.

[0136] Computer storage media 903, such as those in 11 to 16, include a storage medium body for storing computer programs; when the computer program is executed by a microprocessor, it implements any of the above-mentioned exhaust gas flow diagnosis methods; in addition, its controller 901 includes any of the above-mentioned engine management devices 909; and / or any computer storage medium 903; all of which adopt inventive concepts corresponding to the method of the present invention, and their implementation process will not be described in detail.

[0137] It should be noted that the above embodiments are only for more clearly illustrating the technical solution of the present invention. Those skilled in the art will understand that the implementation of the present invention is not limited to the above content. Any obvious changes, substitutions or replacements made based on the above content do not exceed the scope of the technical solution of the present invention. Other implementations will also fall within the scope of the present invention without departing from the concept of the present invention.

Claims

1. A method for diagnosing exhaust gas flow rate, characterized in that, It includes a first detection and treatment step (100) and a second diagnosis and confirmation step (200); wherein, the first detection and treatment step (100) includes a first detection step (110) and a first second treatment step (120). The first detection step (110) acquires operating condition information (199) and makes a judgment based on preset diagnostic preconditions. If the diagnostic preconditions are met, the first and second handling steps (120) are executed. In the first and second handling steps (120), at the first moment M1, the flow channel of the first coolant in the first heat exchange circuit where the exhaust gas recirculation EGR cooler (709) is located is cut off, and the remaining part of the first coolant enters the second heat exchange circuit through the bypass channel (736) of the EGR cooler (709). 120) Record the initial temperature vector VT at the first moment M1; the initial temperature vector VT includes the initial value of the first temperature TA and the initial value of the second temperature TB; the first temperature TA is collected from the first heat exchange circuit, and the second temperature TB is collected from the second heat exchange circuit; adjust the exhaust gas recirculation (EGR) valve (716) to change the heat transferred to the EGR cooler (709), the EGR valve (716) is located between the air side (719) of the EGR cooler and the engine intake unit (714), and is used to control the flow or shut-off of EGR exhaust gas; The second diagnostic and confirmation step (200) includes a second diagnostic step (210) and a second confirmation step (220); the second diagnostic step (210) scans or repeatedly acquires the first temperature TA at a preset time interval; the second diagnostic step (210) acquires the first temperature rise △T1 of the first temperature TA, where the first temperature rise △T1 is the increase value of the first temperature TA; the second confirmation step (220) compares the relationship between the first temperature rise △T1 and the preset temperature rise range, judges the fault state, confirms and executes a reset operation (222), whereby the reset operation (222) opens the flow channel in the first heat exchange circuit and closes the bypass channel (736).

2. The exhaust gas flow rate diagnosis method as described in claim 1, wherein: The diagnostic prerequisites include a first prerequisite and a second prerequisite. When the first prerequisite or the second prerequisite is met, the diagnostic prerequisites are met, and when the diagnostic prerequisites are met, there must be no predefined fault markers. The first prerequisite includes at least one of the following conditions: the first temperature TA is less than threshold L1, the second temperature TB is less than threshold L2, the engine running time after starting is greater than threshold L3, the engine speed is greater than threshold L4, and the EGR valve (716) is closed; the thresholds L1, L2, L3, and L4 are all calibrated values, which are obtained through tests or experiments; The second prerequisite includes at least one of the following conditions: the first temperature TA is less than threshold H1, the second temperature TB is less than threshold H2, the engine running time after startup is greater than threshold H3, the engine speed is greater than threshold H4, and the EGR valve (716) is closed.

3. The exhaust gas flow rate diagnosis method as described in claim 2, wherein: If the first prerequisite and / or the second prerequisite are met, then the following fault markers must not exist: EGR coolant temperature sensor (730) fault, engine coolant temperature sensor (727) fault, EGR low flow fault, EGR high flow fault, engine coolant temperature sensor related fault, EGR valve related fault, EGR cooling branch solenoid valve drive stage fault, EGR bypass branch solenoid valve drive stage fault.

4. The exhaust gas flow rate diagnosis method as described in any one of claims 1, 2, or 3, wherein: The second heat exchange circuit includes the bypass channel (736), the second valve (738), the engine radiator (722), the cooling water pump (721), and the cooling water passage (728) of the engine body; the first coolant is exhaust gas recirculation (EGR) coolant; the engine intake unit (714) includes an intake pipe or an intake manifold; The second temperature TB is collected from any of the following locations: engine cylinder head water temperature sensor, cylinder block water temperature sensor, engine coolant outlet water temperature sensor, engine coolant inlet water temperature sensor, and radiator outlet water temperature sensor.

5. The exhaust gas flow rate diagnosis method as described in claim 4 further includes a flow rate integration step (213) and a first temperature rise discrimination step (214); the flow rate integration step (213) detects the target flow rate integral A1 until the target flow rate integral A1 is greater than the first target flow rate integral threshold TIF; wherein, If the EGR valve (716) is open and the EGR target flow rate F is less than or equal to the first target flow rate threshold TF, then the target flow rate integral A1 is cleared to zero; otherwise, the EGR target flow rate F is continuously integrated. During this process, if the first temperature TA is greater than or equal to the first discrimination temperature threshold TTL, the reset operation (222) is performed and the first detection step (110) is re-entered; in addition, if the target flow integral A1 is greater than the first target flow integral threshold TIF, the first temperature rise discrimination step (214) is entered. The first temperature rise discrimination step (214) records the current value of the first temperature TA and calculates the first temperature rise △T1, where the first temperature rise △T1 is the difference between the current value of the first temperature TA and the initial value of the first temperature TA. Record the current value of the second temperature TB and calculate the second temperature rise △T2, where the second temperature rise △T2 is the difference between the current value of the second temperature and the initial value of the second temperature TB; wherein, both △T1 and △T2 are greater than zero; at this time, if △T2 is less than the first engine temperature rise threshold TL, then re-enter the flow integration step (213); in addition, if △T1 is less than the low flow temperature rise threshold, then confirm that there is a low flow fault in EGR; otherwise, the low flow fault does not exist; wherein, the physical quantities used to calculate the flow parameters include engine intake manifold pressure, engine intake load and / or engine intake flow rate.

6. The exhaust gas flow rate diagnosis method as described in claim 4 further includes a flow rate timing step (215) and a second temperature rise determination step (216); the flow rate timing step (215) detects the timer time Ti until the timer time Ti is greater than the second timer threshold TT; wherein, If the high flow rate timing condition is not met, the timer time Ti is reset to zero; otherwise, the timer time Ti starts counting from zero; during this period, if the first temperature TA is greater than or equal to the second discrimination temperature threshold TTH, the reset operation (222) is performed and the first detection step (110) is re-entered; in addition, if the timer time Ti is greater than the second timer threshold TT, the second temperature rise discrimination step (216) is entered. The second temperature rise discrimination step (216) records the current value of the first temperature TA and calculates the third temperature rise △T3, where the third temperature rise △T3 is the difference between the current value of the first temperature TA and the initial value of the first temperature; Record the current value of the second temperature TB and calculate the fourth temperature rise △T4, where the fourth temperature rise △T4 is the difference between the current value of the second temperature TB and the initial value of the second temperature TB; and obtain the cooling water circuit temperature deviation △T5, where the cooling water circuit temperature deviation △T5 is equal to the difference between the current value of the first temperature TA and the current value of the second temperature; wherein, △T3 and △T4 are both greater than zero; At this time, if the fourth temperature rise △T4 is greater than or equal to the second engine temperature rise threshold TH, the flow timing step (215) is restarted; in addition, if △T3 is greater than the preset threshold and △T5 is greater than the preset threshold, it is confirmed that there is a high flow fault in EGR; otherwise, the high flow fault does not exist.

7. The exhaust gas flow rate diagnosis method as described in claim 5 or 6, wherein: The time elapsed between the first moment M1 and the engine start moment MS is less than the preset warm-up time threshold TX, where TX is a positive integer.

8. An engine management device (909), comprising a first detection and processing unit (910) and a second diagnosis and confirmation unit (920); wherein, The first detection and processing unit (910) includes a first detection unit (911) and a first processing unit (912). The first detection unit (911) acquires operating condition information (199) and makes a judgment based on preset diagnostic preconditions. If the diagnostic preconditions are met, the information is handed over to the first second processing unit (912) for processing. Specifically, the first second processing unit (912) cuts off the flow channel of the first coolant in the first heat exchange circuit where the exhaust gas recirculation (EGR) cooler (709) is located at the first moment M1. The remaining portion of the first coolant enters the second heat exchange circuit through the bypass channel (736) of the EGR cooler (709). (912) Record the initial temperature vector VT at the first moment M1; the initial temperature vector VT includes the initial value of the first temperature TA and the initial value of the second temperature TB; the first temperature TA is collected from the first heat exchange circuit and the second temperature TB is collected from the second heat exchange circuit; adjust the exhaust gas recirculation (EGR) valve (716) to change the heat transferred to the EGR cooler (709), the EGR valve (716) is located between the air side (719) of the EGR cooler and the engine intake unit (714), and is used to control the flow or shut-off of EGR exhaust gas; The second diagnostic and confirmation unit (920) includes a second diagnostic unit (921) and a second confirmation unit (922); the second diagnostic unit (921) scans or repeatedly acquires the first temperature TA at a preset time interval; the second diagnostic unit (921) acquires the first temperature rise △T1 of the first temperature TA, the first temperature rise △T1 being the increase value of the first temperature TA; the second confirmation unit (922) compares the relationship between the first temperature rise △T1 and the preset temperature rise range, judges the fault state, confirms and executes a reset operation (222), the reset operation (222) opening the flow channel in the first heat exchange circuit and closing the bypass channel (736).

9. The engine management device (909) as claimed in claim 8, wherein: The diagnostic prerequisites include a first prerequisite and a second prerequisite. When the first prerequisite or the second prerequisite is met, the diagnostic prerequisites are met, and when the diagnostic prerequisites are met, there must be no predefined fault markers. The first prerequisite includes at least one of the following conditions: the first temperature TA is less than threshold L1, the second temperature TB is less than threshold L2, the engine running time after starting is greater than threshold L3, the engine speed is greater than threshold L4, and the EGR valve (716) is closed; the thresholds L1, L2, L3, and L4 are all calibrated values, which are obtained through tests or experiments; The second prerequisite includes at least one of the following conditions: the first temperature TA is less than threshold H1, the second temperature TB is less than threshold H2, the engine running time after startup is greater than threshold H3, the engine speed is greater than threshold H4, and the EGR valve (716) is closed.

10. The engine management device (909) as claimed in claim 9, wherein: If the first prerequisite and / or the second prerequisite are met, then the following fault markers must not exist: EGR coolant temperature sensor (730) fault, engine coolant temperature sensor (727) fault, EGR low flow fault, EGR high flow fault, engine coolant temperature sensor related fault, EGR valve related fault, EGR cooling branch solenoid valve drive stage fault, EGR bypass branch solenoid valve drive stage fault.

11. The engine management device (909) as claimed in any one of claims 8, 9, or 10, wherein: The second heat exchange circuit includes the bypass channel (736), the second valve (738), the engine radiator (722), the cooling water pump (721), and the cooling water passage (728) of the engine body; the first coolant is exhaust gas recirculation (EGR) coolant; the engine intake unit (714) includes an intake pipe or an intake manifold; The second temperature TB is collected from any of the following locations: engine cylinder head water temperature sensor, cylinder block water temperature sensor, engine coolant outlet water temperature sensor, engine coolant inlet water temperature sensor, radiator outlet water temperature sensor; the time elapsed between the first moment M1 and the engine start moment MS is less than the preset warm-up time threshold TX, where TX is a positive integer.

12. The engine management device (909) as claimed in claim 11 further includes a flow integration unit and a first temperature rise discrimination unit; the flow integration unit detects a target flow integration A1 until the target flow integration A1 is greater than a first target flow integration threshold TIF; wherein, If the EGR valve (716) is open and the EGR target flow rate F is less than or equal to the first target flow rate threshold TF, then the target flow rate integral A1 is cleared to zero; otherwise, the EGR target flow rate F is integrated; during this period, if the first temperature TA is greater than or equal to the first discrimination temperature threshold TTL, then the reset operation (222) is performed and the data is returned to the first detection unit (911) for processing. Furthermore, if the target flow integral A1 is greater than the first target flow integral threshold TIF, then it is handled by the first temperature rise discrimination unit. The first temperature rise discrimination unit records the current value of the first temperature TA and calculates the first temperature rise △T1, where the first temperature rise △T1 is the difference between the current value of the first temperature TA and the initial value of the first temperature TA. Record the current value of the second temperature TB and calculate the second temperature rise ΔT2, which is the difference between the current value of the second temperature and the initial value of the second temperature TB; wherein, ΔT1 and ΔT2 are both greater than zero; at this time, if ΔT2 is less than the first engine temperature rise threshold TL, it is reprocessed by the flow integration unit; in addition, if ΔT1 is less than the low flow temperature rise threshold, it is confirmed that there is a low flow fault in EGR; otherwise, the low flow fault does not exist; wherein, the physical quantities used to calculate the flow parameters include engine intake manifold pressure, engine intake load and / or engine intake flow rate.

13. The engine management device (909) as claimed in claim 11 further includes a flow timing unit and a second temperature rise discrimination unit; the flow timing unit detects a timer time Ti until the timer time Ti is greater than a second timer threshold TT; wherein, If the high-flow timing condition is not met, the timer time Ti is reset to zero. Otherwise, the timer time Ti starts counting from zero; during this period, if the first temperature TA is greater than or equal to the second discrimination temperature threshold TTH, the reset operation (222) is performed and the data is returned to the first detection unit (911) for processing. Furthermore, if the timer duration Ti is greater than the second timer threshold TT, then the process is handed over to the second temperature rise discrimination unit. The second temperature rise discrimination unit records the current value of the first temperature TA and calculates the third temperature rise △T3, where the third temperature rise △T3 is the difference between the current value of the first temperature TA and the initial value of the first temperature; Record the current value of the second temperature TB and calculate the fourth temperature rise △T4, which is the difference between the current value of the second temperature TB and the initial value of the second temperature TB; and obtain the cooling water circuit temperature deviation △T5, which is equal to the difference between the current value of the first temperature TA and the current value of the second temperature; wherein, △T3 and △T4 are both greater than zero; at this time, if the fourth temperature rise △T4 is greater than or equal to the second engine temperature rise threshold TH, then it is reprocessed by the flow timing unit; in addition, if △T3 is greater than a preset threshold and △T5 is greater than a preset threshold, then it is confirmed that there is a high flow fault in EGR; otherwise, the high flow fault does not exist.

14. A computer storage medium (903) comprising a storage medium body for storing a computer program; wherein the computer program, when executed by a microprocessor, implements the exhaust gas flow diagnosis method as described in any one of claims 1 to 7.

15. A controller (901) comprising an engine management device (909) as claimed in any one of claims 8 to 13; and / or a computer storage medium (903) as claimed in claim 14.

Images