EGR (Exhaust Gas Recirculation) flow abnormality diagnosis method and device, engine controller and vehicle

Abstract

The embodiment of the invention provides an EGR flow abnormity diagnosis method and device, an engine controller and a vehicle. The method comprises the steps that a mixing valve located on an intake manifold is controlled to reach a first target opening degree for diagnosis, a throttle valve located on the intake manifold is controlled to reach a second target opening degree for diagnosis, and an EGR valve located on an EGR pipeline is controlled to reach a third target opening degree for diagnosis, a part of ERG flow discharged from an air outlet of the engine enters an air inlet manifold connected with an air inlet of the engine through an EGR pipeline; a real-time pressure value collected by a pressure sensor located at the downstream of the EGR pipeline is obtained; the real-time pressure value is compared with a preset pressure range, and whether EGR flow abnormality exists or not is determined; wherein the preset pressure range is a pre-calibrated pressure value range collected by a pressure sensor at the downstream of the EGR pipeline when the mixing valve is at the first target opening degree, the throttle valve is at the second target opening degree, the EGR valve is at the third target opening degree and the EGR flow is normal.

Description

Technical Field

[0001] This specification relates to the field of automotive technology, and in particular to a diagnostic method, device, engine controller, and vehicle for EGR flow anomalies. Background Technology

[0002] In response to the challenge of global warming, various industries have introduced technologies to reduce greenhouse gas emissions. For example, in the automotive sector, exhaust gas recirculation (EGR) technology is commonly used in hybrid vehicles and traditional vehicles equipped with air-breathing engines to treat vehicle exhaust emissions.

[0003] EGR technology refers to the process of returning a portion of the exhaust gas from the engine to the intake manifold, where it is mixed with fresh air and re-enters the cylinder. Since the exhaust gas contains a large amount of polyatomic gases such as CO2, which are non-combustible but absorb a significant amount of heat due to their high specific heat capacity, the maximum combustion temperature of the air-fuel mixture in the cylinder is lowered, thereby reducing the generation of greenhouse gases such as nitrogen oxides (NOx).

[0004] In actual operation, EGR systems can only function efficiently within a set EGR flow range to minimize the generation of nitrogen oxides. To better perform EGR, the vehicle's on-board diagnostics (OBD) system continuously monitors the EGR flow to identify abnormal EGR flow patterns, such as excessively low or high flow rates.

[0005] Current OBD systems typically rely on EGR temperature sensors to diagnose abnormal EGR flow rates. Excessive EGR flow occurs during cold starts: during a cold start period, the EGR valve is closed. If the EGR flow is not too high, the EGR temperature rises slowly; conversely, if the EGR flow is too high, the EGR temperature rises quickly. This physical characteristic of temperature rise rate allows for the diagnosis of excessively high EGR flow. Similarly, insufficient EGR flow occurs when the EGR valve begins operation but the EGR temperature is not yet high: during the period when the EGR valve is open, if the EGR flow is not too low, the EGR temperature rises quickly; conversely, if the EGR flow is too low, the EGR temperature rises slowly. This physical characteristic of temperature rise rate allows for the diagnosis of excessively low EGR flow.

[0006] The aforementioned scheme for diagnosing EGR flow anomalies based on EGR temperature has several limitations. Firstly, it requires defining specific operating conditions (high EGR flow diagnosis relies on cold start conditions, while low EGR flow diagnosis requires low EGR temperature conditions). This limitation makes diagnosis difficult under non-specific operating conditions. Secondly, EGR temperature changes are affected not only by the EGR flow rate but also by interfering factors such as cooling water and air intake. These interfering factors make the calibration of the relationship between EGR temperature and EGR flow rate particularly complex, making it difficult to accurately measure the relationship between them.

[0007] In summary, diagnosing EGR flow anomalies based on EGR temperature suffers from low robustness and complex calibration procedures. Summary of the Invention

[0008] In view of this, one or more embodiments of this specification provide a method, apparatus, engine controller, and vehicle for diagnosing abnormal EGR flow, in order to solve the problems existing in the related art.

[0009] To achieve the above objectives, one or more embodiments of this specification provide the following technical solutions: According to a first aspect of the embodiments of this specification, a method for diagnosing EGR flow anomalies is provided, the method comprising: Controlling the mixing valve located in the intake manifold to a first target opening for diagnostics, controlling the throttle valve located in the intake manifold to a second target opening for diagnostics, and controlling the EGR valve located in the EGR line to a third target opening for diagnostics, so as to allow a portion of the ERG flow from the engine outlet to enter the intake manifold connected to the engine intake via the EGR line. Obtain the real-time pressure value collected by the pressure sensor located downstream of the EGR pipeline; The real-time pressure value is compared with the preset pressure range to determine whether there is an abnormal EGR flow. The preset pressure range is a pre-calibrated range of pressure values ​​collected by the pressure sensor downstream of the EGR pipeline when the mixing valve is at the first target opening, the throttle valve is at the second target opening, and the EGR valve is at the third target opening and the EGR flow is normal.

[0010] Optionally, before controlling the mixing valve located in the intake manifold to a first target opening for diagnostics, controlling the throttle valve located in the intake manifold to a second target opening for diagnostics, and controlling the EGR valve located in the EGR line to a third target opening for diagnostics, the method further includes: By using the electric motor to reverse the engine, the engine is put into a deceleration and fuel cut-off state, thereby controlling the vehicle's operating condition to be adjusted to a deceleration state.

[0011] Optionally, before acquiring the real-time pressure value collected by the pressure sensor located downstream of the EGR pipeline, the method further includes: After controlling the mixing valve to a first target opening degree for diagnostics, the throttle valve to a second target opening degree for diagnostics, and the EGR valve to a third target opening degree for diagnostics, wait for a first preset time.

[0012] Optionally, the EGR traffic anomaly includes an anomaly of excessively high EGR traffic and / or an anomaly of excessively low EGR traffic; The step of determining whether there is an EGR flow anomaly by comparing the real-time pressure value with a preset pressure range includes at least one of the following: When the opening of the mixing valve and throttle valve in the intake manifold remains unchanged, the real-time pressure value is compared with the lower limit threshold of the preset pressure range. If the real-time pressure value is less than or equal to the lower limit threshold, it is determined that there is an abnormality of excessively low EGR flow. When the opening of the mixing valve and throttle valve in the intake manifold remains unchanged, the real-time pressure value is compared with the upper limit threshold of the preset pressure range. If the real-time pressure value is greater than or equal to the upper limit threshold, it is determined that there is an abnormality of excessive EGR flow.

[0013] Optional, also includes: When the opening of the mixing valve and throttle valve in the intake manifold changes, an abnormality factor is calculated based on the real-time pressure value and the real-time intake air flow entering the intake manifold through the throttle valve; wherein, the abnormality factor characterizes the magnitude of the EGR flow abnormality. The presence of EGR traffic anomalies is determined by comparing the anomaly factor with a preset threshold range.

[0014] Optionally, the step of calculating the abnormal factor based on the real-time pressure value and the real-time intake airflow entering the intake manifold via the throttle valve includes: Obtain the desired pressure value corresponding to the real-time intake flow rate; The fault factor is obtained by dividing the real-time pressure value by the expected pressure value.

[0015] Optionally, the EGR traffic anomaly includes an anomaly of excessively high EGR traffic and / or an anomaly of excessively low EGR traffic; The step of determining whether there is an EGR traffic anomaly by comparing the anomaly factor with a preset threshold range includes at least one of the following: The abnormal factor is compared with the lower limit of the preset threshold range. If the abnormal factor is less than or equal to the lower limit threshold, it is determined that there is an abnormality of excessively low EGR flow. The abnormal factor is compared with the upper limit of the preset threshold range. If the abnormal factor is greater than or equal to the upper limit threshold, it is determined that there is an abnormality of excessively high EGR traffic.

[0016] Optionally, the step of calculating the abnormal factor based on the real-time pressure value and the real-time intake airflow entering the intake manifold via the throttle valve includes: The pressure sensor periodically collects several real-time pressure values ​​within a second preset time period, as well as the real-time intake flow rate entering the intake manifold through the throttle valve during the collection. Based on the real-time pressure value and real-time intake flow rate collected in each cycle, the abnormal factors at the time of collection in each cycle are calculated. Calculate the average value among all abnormal factors within the second preset time period, and use the average value as the abnormal factor for comparison with a preset threshold range.

[0017] Optionally, the abnormal EGR traffic includes excessively high EGR traffic and / or excessively low EGR traffic; The control of the EGR valve located in the EGR line to a third target opening degree for diagnostic purposes includes at least one of the following: To diagnose abnormalities such as excessive EGR flow, shut off the EGR valve located in the EGR pipeline; To diagnose abnormalities such as low EGR flow, control the EGR valve located in the EGR pipeline to its maximum opening.

[0018] According to a second aspect of the embodiments of this specification, a diagnostic device for EGR flow anomalies is provided, the device comprising: The adjustment unit controls the mixing valve located in the intake manifold to a first target opening for diagnostics, controls the throttle valve located in the intake manifold to a second target opening for diagnostics, and controls the EGR valve located in the EGR line to a third target opening for diagnostics, so as to allow a portion of the ERG flow from the engine outlet to enter the intake manifold connected to the engine intake via the EGR line. The acquisition unit acquires the real-time pressure value collected by the pressure sensor located downstream of the EGR pipeline; The diagnostic unit compares the real-time pressure value with a preset pressure range to determine whether there is an abnormal EGR flow. The preset pressure range is a pre-calibrated range of pressure values ​​collected by the pressure sensor downstream of the EGR pipeline when the mixing valve is at the first target opening, the throttle valve is at the second target opening, and the EGR valve is at the third target opening and the EGR flow is normal.

[0019] According to a third aspect of the embodiments of this specification, an engine controller is provided, including a processor; a memory for storing processor-executable instructions; wherein the processor implements the above-described method by executing the executable instructions; According to a fourth aspect of the embodiments of this specification, a vehicle is provided, the vehicle having the above-described engine controller.

[0020] The technical solutions provided in the embodiments of this specification may include the following beneficial effects: Because EGR technology requires a portion of the exhaust gas from the engine (EGR flow) to be returned to the intake manifold via the EGR pipeline, a pressure sensor can be installed downstream of the EGR pipeline (close to the intake manifold). The pressure value collected by this sensor can then directly reflect changes in the EGR flow rate. This eliminates the need for an EGR temperature sensor, thus eliminating interference from other heat sources affecting EGR temperature, such as coolant and airflow, improving the robustness of diagnostic results and simplifying calibration. Furthermore, the pressure sensor responds to changes in the flow rate throughout the entire EGR circuit, resulting in more accurate diagnostic results.

[0021] On the other hand, a mixing valve (MixVlv) is installed in the intake manifold. By controlling the mixing valve and the throttle valve (ThrVlv), also located in the intake manifold, to the first and second target opening degrees used for diagnostics, a stable negative pressure is provided downstream of the EGR pipeline. Combined with controlling the EGR valve in the EGR pipeline to the third target opening degree, a portion of the ERG flow from the engine's exhaust port is diverted through the EGR pipeline into the intake manifold. This actively creates diagnostic conditions for the pressure sensor downstream of the EGR pipeline.

[0022] On the other hand, by proactively creating diagnostic conditions and using the electric motor to reverse the engine to put it in a deceleration fuel cut-off state (DFCO), the diagnostic conditions that are not affected by the engine's operating conditions can be proactively created, which can improve the robustness of the diagnostic results. Attached Figure Description

[0023] Figure 1 A system architecture diagram of a diagnostic system provided as an exemplary embodiment of this specification; Figure 2 A flowchart illustrating an exemplary embodiment of this specification, showing a method for diagnosing EGR flow anomalies; Figure 3 A schematic diagram illustrating an abnormal EGR flow as provided in an exemplary embodiment of this specification; Figure 4 A schematic diagram of EGR flow anomalies based on anomaly factors provided for an exemplary embodiment of this specification; Figure 5A schematic diagram of the structure of an electronic device containing a diagnostic device for EGR flow anomalies, provided as an exemplary embodiment of this specification; Figure 6 This is a block diagram of a diagnostic device for EGR flow anomalies provided as an exemplary embodiment of this specification. Detailed Implementation

[0024] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with one or more embodiments of this specification. Rather, they are merely examples of apparatuses and methods consistent with some aspects of one or more embodiments of this specification as detailed in the appended claims.

[0025] It should be noted that the steps of the corresponding methods are not necessarily performed in the order shown and described in this specification in other embodiments. In some other embodiments, the methods may include more or fewer steps than described in this specification. Furthermore, a single step described in this specification may be broken down into multiple steps in other embodiments; and multiple steps described in this specification may be combined into a single step in other embodiments.

[0026] The diagnostic scheme for EGR flow anomalies in this manual will be described in detail below with reference to the accompanying drawings.

[0027] Please refer to Figure 1 The diagram shows a system architecture for a diagnostic system for EGR traffic anomalies. Figure 1 As shown, the system may include an intake manifold for intake, a mixing valve (MixVlv) and a throttle valve (ThrVlv) located in the intake manifold, the intake manifold being connected to the engine's intake port; the engine is controlled by an electric motor, the engine's outlet being connected to an exhaust pipe for exhaust; the exhaust pipe is connected to the intake manifold via an EGR pipe, and the EGR valve (EGRVlv) located in the EGR pipe controls the amount of exhaust gas discharged from the exhaust pipe returning to the intake manifold via the EGR flow rate; a pressure sensor is also located downstream of the EGR pipe.

[0028] The throttle valve and mixing valve are used to provide a stable negative pressure downstream of the EGR pipeline, thereby improving diagnostic robustness. The EGR valve is used to provide the EGR base flow rate to the EGR pipeline.

[0029] The diagnostic solution for EGR flow anomalies provided in this manual utilizes a pressure sensor installed downstream of the EGR pipeline (near the intake manifold). The pressure value collected by this sensor directly reflects changes in EGR flow. This eliminates the need for an EGR temperature sensor, thus ruling out interference from other heat sources affecting EGR temperature, such as cooling water and airflow, improving the robustness of the diagnostic results and simplifying calibration. Furthermore, the pressure sensor responds to flow changes throughout the entire EGR loop, resulting in more accurate diagnostic results.

[0030] The diagnostic solutions provided in this manual are applicable to all vehicles equipped with engines, including but not limited to conventional gasoline vehicles, hybrid vehicles, and range-extended vehicles.

[0031] Please refer to the following for further information. Figure 2 , Figure 2 A flowchart illustrating an exemplary embodiment of this specification provides a method for diagnosing EGR traffic anomalies, the method comprising: Step 210: Control the mixing valve located in the intake manifold to a first target opening for diagnostics, control the throttle valve located in the intake manifold to a second target opening for diagnostics, and control the EGR valve located in the EGR line to a third target opening for diagnostics, so as to allow a portion of the ERG flow from the engine outlet to enter the intake manifold connected to the engine intake via the EGR line.

[0032] In combination with the above Figure 1 The system architecture diagram described above can also include a system self-test step before step 210. For example, it can check for faults in the mixing valve, throttle valve, EGR valve, and pressure sensor. If a fault is found, step 210 cannot be triggered to perform the diagnostic process.

[0033] If no fault is found, step 210 can be triggered to adjust the opening of the mixing valve to the first target opening, the throttle valve to the second target opening, and the EGR valve to the third target opening. The first, second, and third target openings can be the same or different, depending on the experimental results of different vehicle models. When diagnosing abnormal EGR flow, the mixing valve, throttle valve, and EGR valve are adjusted to their respective target openings to ensure consistent objective conditions for each diagnosis.

[0034] In one exemplary embodiment, the process may further include the following steps prior to step 210: By using the electric motor to reverse the engine, the engine is put into a deceleration and fuel cut-off state, thereby controlling the vehicle's operating condition to be adjusted to a deceleration state.

[0035] In practical applications, the hybrid engine shuts off when the vehicle decelerates. For diagnostic purposes, the electric motor can be controlled to reverse, allowing the engine to continue running while cutting off fuel, thus actively creating a deceleration fuel cut-off state. This approach is unaffected by engine operating conditions and also improves diagnostic accuracy.

[0036] Step 220: Obtain the real-time pressure value collected by the pressure sensor located downstream of the EGR pipeline.

[0037] Because of the third target opening of the EGR valve, a portion of the EGR flow from the engine exhaust will flow back to the intake manifold through the EGR pipe. The magnitude of this EGR flow directly affects the pressure sensor downstream of the EGR pipe. In other words, the real-time pressure value collected by this pressure sensor characterizes the real-time magnitude of the EGR flow.

[0038] It is worth mentioning that since the adjustment of the opening degrees of the mixing valve, throttle valve, and EGR valve affects the ERG flow rate, in order to ensure more stable pressure values ​​collected by the pressure sensor, a first preset time can be waited after the mixing valve, throttle valve, and EGR valve are adjusted to their respective target opening degrees. This allows for the collection of stable real-time pressure values ​​after the wait. For example, the first preset time can be flexibly set according to actual needs, such as 3 seconds, 5 seconds, etc.

[0039] In addition, since pressure sensors are used for anomaly diagnosis, the EGR temperature sensor can be eliminated, thus saving hardware costs.

[0040] Step 230: Compare the real-time pressure value with the preset pressure range to determine whether there is an abnormal EGR flow; wherein, the preset pressure range is a pre-calibrated range of pressure values ​​collected by the pressure sensor downstream of the EGR pipeline when the mixing valve is at the first target opening, the throttle valve is at the second target opening, and the EGR valve is at the third target opening and the EGR flow is normal.

[0041] In this manual, the calibration environment is set up to be the same as that used in actual diagnosis (the mixing valve is at the first target opening, the throttle valve is at the second target opening, and the EGR valve is at the third target opening), and the range of pressure values ​​collected by the pressure sensor downstream of the EGR pipeline is measured when the EGR flow is normal.

[0042] For example, by physically simulating or software-simulating the EGR system's operating scenarios, experimental tests can be conducted on the EGR flow rate. For instance, each experiment simulates the same conditions as a real diagnostic test, but with different EGR flow rates emitted by the engine, and the pressure values ​​collected by the pressure sensor under different EGR flow rates are recorded. Through multiple experiments and analysis of the experimental test data, a more accurate pressure range can be obtained, and this pressure range can be calibrated as the preset pressure range.

[0043] It should be noted that since normal EGR traffic falls within a certain range, the corresponding normal pressure value also falls within a range, such as [A, B]. Here, A can be understood as the lower threshold of the normal pressure value, and B as the upper threshold of the normal pressure value. Thus, when the real-time pressure value is within [A, B], the EGR traffic is considered normal, while when the real-time pressure value is not within [A, B], the EGR traffic is considered abnormal.

[0044] Generally, abnormal EGR traffic can be divided into abnormalities of excessively high EGR traffic and / or abnormalities of excessively low EGR traffic.

[0045] Based on this, the above method of determining whether there is an EGR flow anomaly by comparing the real-time pressure value with a preset pressure range may include at least one of the following: When the opening of the mixing valve and throttle valve in the intake manifold remains unchanged, the real-time pressure value is compared with the lower limit threshold of the preset pressure range. If the real-time pressure value is less than or equal to the lower limit threshold, it is determined that there is an abnormality of excessively low EGR flow. When the opening of the mixing valve and throttle valve in the intake manifold remains unchanged, the real-time pressure value is compared with the upper limit threshold of the preset pressure range. If the real-time pressure value is greater than or equal to the upper limit threshold, it is determined that there is an abnormality of excessive EGR flow.

[0046] The following is combined with Figure 3 The diagram illustrates the abnormal EGR flow. Figure 3 The horizontal axis represents the intake air flow rate under different throttle valve openings, and the vertical axis represents the real-time pressure value collected by the pressure sensor downstream of the EGR pipeline under the same conditions (mixing valve at the first target opening, throttle valve at the second target opening, and EGR valve at the third target opening). Since a larger intake air flow rate results in a smaller proportion of pressure affected by the EGR flow rate as represented by the pressure sensor, because intake air flow rate and pressure range are generally inversely proportional—that is, a larger intake air flow rate results in smaller upper and lower threshold values ​​for the pressure range—for example, with intake air flow rates of 8 g / s and 11 g / s, the lower threshold value for determining excessively low EGR flow rate is significantly higher at 8 g / s than at 11 g / s; similarly, the upper threshold value for determining excessively high EGR flow rate is also significantly higher than at 11 g / s. Therefore, Figure 3 The trend of excessively high, normal, and excessively low EGR flow is that it is higher on the left and lower on the right.

[0047] When the intake air flow rate remains constant (the throttle valve opening of the intake manifold remains constant), if the real-time pressure value collected by the sensor is less than or equal to the lower limit threshold of the preset pressure range, it indicates that the EGR flow rate is too low; while if the real-time pressure value is greater than or equal to the upper limit threshold of the preset pressure range, it indicates that the EGR flow rate is too high.

[0048] In actual diagnostics, changes in the mixing valve and throttle valve may alter the intake airflow, making it difficult to use the diagnostic method. Figure 3 The diagnostic result is determined by directly comparing the real-time pressure value with the preset pressure range.

[0049] Therefore, this specification introduces the concept of anomaly factors to decouple the relationship between EGR flow anomalies and intake flow.

[0050] In an exemplary embodiment, when the opening of the mixing valve and throttle valve of the intake manifold changes, an anomaly factor is calculated based on the real-time pressure value and the real-time intake air flow entering the intake manifold via the throttle valve; wherein the anomaly factor characterizes the magnitude of the EGR flow anomaly. The presence of EGR traffic anomalies is determined by comparing the anomaly factor with a preset threshold range.

[0051] The step of calculating the abnormal factor based on the real-time pressure value and the real-time intake airflow entering the intake manifold via the throttle valve may include: Obtain the desired pressure value corresponding to the real-time intake flow rate; The fault factor is obtained by dividing the real-time pressure value by the expected pressure value.

[0052] In this embodiment, the abnormality factor can objectively reflect the degree of abnormality in EGR flow and is not affected by the intake flow rate; the abnormality factor is calculated to determine whether the EGR flow rate is abnormal.

[0053] Similar to the comparison between real-time pressure values ​​and preset pressure ranges mentioned above, the preset threshold range can also be calibrated by physically simulating or simulating the EGR system operating scenario.

[0054] The preset threshold range can be denoted as [C, D], where C can be understood as the lower threshold of the abnormal factor, and D is the upper threshold of the abnormal factor. Thus, when the abnormal factor is within [C, D], the EGR traffic is considered normal, and when the abnormal factor is not within [C, D], the EGR traffic is considered abnormal.

[0055] Based on this, the above method of determining whether there is an EGR traffic anomaly by comparing the anomaly factor with a preset threshold range includes at least one of the following: The abnormal factor is compared with the lower limit of the preset threshold range. If the abnormal factor is less than or equal to the lower limit threshold, it is determined that there is an abnormality of excessively low EGR flow. The abnormal factor is compared with the upper limit of the preset threshold range. If the abnormal factor is greater than or equal to the upper limit threshold, it is determined that there is an abnormality of excessively high EGR traffic.

[0056] The following is combined with Figure 4 The diagram illustrates EGR traffic anomalies based on anomaly factors. To ensure that the anomaly factors more accurately reflect the degree of EGR traffic anomalies, the average value of multiple anomaly factors over a period of time can be calculated to ultimately confirm whether an EGR traffic fault exists.

[0057] For example, the step of calculating the anomaly factor based on the real-time pressure value and the real-time intake airflow entering the intake manifold via the throttle valve may include: The pressure sensor periodically collects several real-time pressure values ​​within a second preset time period, as well as the real-time intake flow rate entering the intake manifold through the throttle valve during the collection. Based on the real-time pressure value and real-time intake flow rate collected in each cycle, the abnormal factors at the time of collection in each cycle are calculated. Calculate the average value among all abnormal factors within the second preset time period, and use the average value as the abnormal factor for comparison with a preset threshold range.

[0058] In this embodiment, by calculating the average value of several abnormal factors calculated within a second preset time period, it can be considered that the abnormal factor is greater than or equal to the upper limit threshold of the preset threshold range (e.g., ...). Figure 4 When the value shown is 1.04), there is an anomaly of excessively high EGR flow; while the anomaly factor is less than or equal to the lower limit of the preset threshold range (e.g., ...). Figure 4 The value of 0.96 indicates an abnormally low EGR flow; otherwise, the EGR flow is considered normal. The values ​​of 1.04 and 0.96 here are precise values ​​calculated experimentally.

[0059] The second preset duration can be flexibly set according to actual needs, such as 1 minute, 3 minutes, etc.

[0060] Theoretically, the larger the EGR valve opening, the higher the diagnostic robustness for excessive EGR flow; conversely, the smaller the EGR valve opening, the higher the diagnostic robustness for insufficient EGR flow. Based on this, step 210 may include at least one of the following: For abnormal diagnosis of excessive EGR flow, close the EGR valve located in the EGR pipeline (i.e., minimize the opening). To diagnose abnormalities such as low EGR flow, control the EGR valve located in the EGR pipeline to its maximum opening.

[0061] In this embodiment, for the abnormal diagnosis of excessively high EGR flow and excessively low EGR flow, a more robust EGR valve opening adjustment method is used, which can improve the diagnostic robustness.

[0062] After introducing the methods of exemplary embodiments of this specification, the apparatus, engine controller, and vehicle of exemplary embodiments of this specification will be described next.

[0063] In an exemplary embodiment of this specification, an engine controller is provided, comprising: a processor; and a memory for storing processor-executable instructions; wherein the processor implements the aforementioned EGR flow anomaly diagnostic method by executing the executable instructions. The implementation method and technical effects can be referred to the foregoing method embodiments, and will not be repeated here.

[0064] Figure 5 This is a schematic structural diagram of an engine controller provided in an exemplary embodiment. At the hardware level, the engine controller includes a processor, an internal bus, a network interface, memory, and non-volatile memory, and may also include other hardware required for business operations. One or more embodiments of this specification can be implemented in software, such as the processor reading the corresponding computer program from non-volatile memory into memory and then running it. Of course, besides software implementation, one or more embodiments of this specification do not exclude other implementation methods, such as logic devices or a combination of hardware and software, etc. That is to say, the execution entity of the following processing flow is not limited to individual logic units, but can also be hardware or logic devices.

[0065] In an exemplary embodiment of this specification, a vehicle is also provided, which has the aforementioned engine controller. This engine controller enables the aforementioned method for diagnosing EGR flow anomalies; its implementation and technical effects can be found in the foregoing method embodiments, and will not be repeated here.

[0066] In exemplary embodiments of this specification, such as Figure 6 The diagram also provides a diagnostic device for EGR flow anomalies, the device comprising: The adjustment unit 610 controls the mixing valve located in the intake manifold to a first target opening for diagnostics, controls the throttle valve located in the intake manifold to a second target opening for diagnostics, and controls the EGR valve located in the EGR line to a third target opening for diagnostics, so as to allow a portion of the ERG flow from the engine outlet to enter the intake manifold connected to the engine intake via the EGR line. The acquisition unit 620 acquires the real-time pressure value collected by the pressure sensor located downstream of the EGR pipeline; The diagnostic unit 630 compares the real-time pressure value with a preset pressure range to determine whether there is an abnormal EGR flow. The preset pressure range is a pre-calibrated range of pressure values ​​collected by the pressure sensor downstream of the EGR pipeline when the mixing valve is at the first target opening, the throttle valve is at the second target opening, and the EGR valve is at the third target opening and the EGR flow is normal.

[0067] Optionally, prior to the adjustment unit 610, the following may also be included: The control unit uses a motor to reverse the engine and put it in a deceleration and fuel-cut-off state, thereby adjusting the vehicle's operating condition to a deceleration state.

[0068] Optionally, before obtaining the value of the acquisition unit 620, the method further includes: The waiting unit waits for a first preset time after controlling the mixing valve to a first target opening degree for diagnostics, the throttle valve to a second target opening degree for diagnostics, and the EGR valve to a third target opening degree for diagnostics.

[0069] Optionally, the EGR traffic anomaly includes an anomaly of excessively high EGR traffic and / or an anomaly of excessively low EGR traffic; The diagnostic unit 630 includes at least one of the following: The first diagnostic subunit compares the real-time pressure value with the lower limit threshold of the preset pressure range when the opening of the mixing valve and throttle valve of the intake manifold remains unchanged. If the real-time pressure value is less than or equal to the lower limit threshold, it determines that there is an abnormality of excessively low EGR flow. The second diagnostic subunit compares the real-time pressure value with the upper limit threshold of the preset pressure range when the opening of the mixing valve and throttle valve in the intake manifold remains unchanged. If the real-time pressure value is greater than or equal to the upper limit threshold, it determines that there is an abnormality of excessive EGR flow.

[0070] Optionally, the device further includes: The calculation unit calculates an anomaly factor based on the real-time pressure value and the real-time intake air flow entering the intake manifold through the throttle valve when the opening of the mixing valve and throttle valve in the intake manifold changes; wherein, the anomaly factor characterizes the magnitude of the EGR flow anomaly. The diagnostic unit 630 is also used to determine whether there is an EGR traffic anomaly by comparing the abnormal factor with a preset threshold range.

[0071] Optionally, the computing unit includes: The first calculation subunit obtains the expected pressure value corresponding to the real-time intake flow rate; and divides the real-time pressure value by the expected pressure value to obtain the fault factor.

[0072] Optionally, the EGR traffic anomaly includes an anomaly of excessively high EGR traffic and / or an anomaly of excessively low EGR traffic; The diagnostic unit 630 determines whether there is an EGR traffic anomaly by comparing the abnormal factor with a preset threshold range, including at least one of the following: The third diagnostic subunit compares the abnormal factor with the lower limit of a preset threshold range. If the abnormal factor is less than or equal to the lower limit threshold, it determines that there is an abnormality of excessively low EGR flow. The fourth diagnostic subunit compares the abnormal factor with the upper limit of a preset threshold range. If the abnormal factor is greater than or equal to the upper limit threshold, it determines that there is an abnormality of excessively high EGR flow.

[0073] Optionally, the calculation unit calculates anomaly factors based on the real-time pressure value and the real-time intake airflow entering the intake manifold via the throttle valve, including: The acquisition subunit acquires several real-time pressure values ​​periodically collected by the pressure sensor within a second preset time period, as well as the real-time intake airflow entering the intake manifold through the throttle valve during acquisition. The second calculation subunit calculates the abnormal factors during each cycle of data collection based on the real-time pressure value and real-time airflow collected in each cycle. The third calculation subunit calculates the average value among all abnormal factors within the second preset time period, and uses the average value as the abnormal factor for comparison with a preset threshold range.

[0074] Optionally, the abnormal EGR traffic includes excessively high EGR traffic and / or excessively low EGR traffic; The adjustment unit 610 includes at least one of the following: The first adjustment subunit, in response to the abnormal diagnosis of excessive EGR flow, closes the EGR valve located in the EGR pipeline; The second adjustment subunit, in response to abnormal diagnosis of low EGR flow, controls the EGR valve located in the EGR pipeline to its maximum opening.

[0075] For details on the implementation process of the functions and roles of each module in the above-mentioned device, please refer to the implementation process of the corresponding steps in the above-mentioned EGR flow anomaly diagnosis method. For relevant parts, please refer to the description of the method implementation method, which will not be repeated here.

[0076] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the units or modules can be selected to achieve the purpose of the solution described in this specification, depending on actual needs. Those skilled in the art can understand and implement this without any inventive effort.

[0077] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer, which can take the form of a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email sending and receiving device, game console, tablet computer, wearable device, or any combination of these devices.

[0078] In a typical configuration, a computer includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0079] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0080] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0081] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0082] The terminology used in one or more embodiments of this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of one or more embodiments of this specification. The singular forms “a,” “described,” and “the” used in one or more embodiments of this specification and in the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0083] It should be understood that although the terms first, second, third, etc., may be used to describe various information in one or more embodiments of this specification, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first information may also be referred to as second information without departing from the scope of one or more embodiments of this specification, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "in response to a determination," or "when," or "in the event of a determination."

[0084] The above description is merely a preferred embodiment of one or more embodiments of this specification and is not intended to limit the scope of one or more embodiments of this specification. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments of this specification should be included within the protection scope of one or more embodiments of this specification.

Claims

1. A method for diagnosing EGR flow anomalies, the method comprising: Controlling the mixing valve located in the intake manifold to a first target opening for diagnostics, controlling the throttle valve located in the intake manifold to a second target opening for diagnostics, and controlling the EGR valve located in the EGR line to a third target opening for diagnostics, so as to allow a portion of the ERG flow from the engine outlet to enter the intake manifold connected to the engine intake via the EGR line. Obtain the real-time pressure value collected by the pressure sensor located downstream of the EGR pipeline; The real-time pressure value is compared with the preset pressure range to determine whether there is an abnormal EGR flow. The preset pressure range is a pre-calibrated range of pressure values ​​collected by the pressure sensor downstream of the EGR pipeline when the mixing valve is at the first target opening, the throttle valve is at the second target opening, and the EGR valve is at the third target opening and the EGR flow is normal.

2. The method of claim 1, further comprising, before controlling the mixing valve located in the intake manifold to a first target opening for diagnostics, controlling the throttle valve located in the intake manifold to a second target opening for diagnostics, and controlling the EGR valve located in the EGR line to a third target opening for diagnostics: By using the electric motor to reverse the engine, the engine is put into a deceleration and fuel cut-off state, thereby controlling the vehicle's operating condition to be adjusted to a deceleration state.

3. The method according to claim 1, further comprising, before acquiring the real-time pressure value collected by the pressure sensor located downstream of the EGR pipeline: After controlling the mixing valve to a first target opening degree for diagnostics, the throttle valve to a second target opening degree for diagnostics, and the EGR valve to a third target opening degree for diagnostics, wait for a first preset time.

4. The method according to claim 1, wherein the EGR traffic anomaly includes an anomaly of excessively high EGR traffic and / or an anomaly of excessively low EGR traffic; The step of determining whether there is an EGR flow anomaly by comparing the real-time pressure value with a preset pressure range includes at least one of the following: When the opening of the mixing valve and throttle valve in the intake manifold remains unchanged, the real-time pressure value is compared with the lower limit threshold of the preset pressure range. If the real-time pressure value is less than or equal to the lower limit threshold, it is determined that there is an abnormality of excessively low EGR flow. When the opening of the mixing valve and throttle valve in the intake manifold remains unchanged, the real-time pressure value is compared with the upper limit threshold of the preset pressure range. If the real-time pressure value is greater than or equal to the upper limit threshold, it is determined that there is an abnormality of excessive EGR flow.

5. The method according to claim 4, further comprising: When the opening of the mixing valve and throttle valve in the intake manifold changes, an abnormality factor is calculated based on the real-time pressure value and the real-time intake air flow entering the intake manifold through the throttle valve; wherein, the abnormality factor characterizes the magnitude of the EGR flow abnormality. The presence of EGR traffic anomalies is determined by comparing the anomaly factor with a preset threshold range.

6. The method according to claim 5, wherein calculating the abnormality factor based on the real-time pressure value and the real-time intake airflow entering the intake manifold via the throttle valve comprises: Obtain the desired pressure value corresponding to the real-time intake flow rate; The fault factor is obtained by dividing the real-time pressure value by the expected pressure value.

7. The method according to claim 5, wherein the EGR traffic anomaly includes an anomaly of excessively high EGR traffic and / or an anomaly of excessively low EGR traffic; The step of determining whether there is an EGR traffic anomaly by comparing the anomaly factor with a preset threshold range includes at least one of the following: The abnormal factor is compared with the lower limit of the preset threshold range. If the abnormal factor is less than or equal to the lower limit threshold, it is determined that there is an abnormality of excessively low EGR flow. The abnormal factor is compared with the upper limit of the preset threshold range. If the abnormal factor is greater than or equal to the upper limit threshold, it is determined that there is an abnormality of excessively high EGR traffic.

8. The method according to claim 5, wherein calculating the abnormality factor based on the real-time pressure value and the real-time intake airflow entering the intake manifold via the throttle valve comprises: The pressure sensor periodically collects several real-time pressure values ​​within a second preset time period, as well as the real-time intake airflow entering the intake manifold through the throttle valve during the collection. Based on the real-time pressure value and real-time intake flow rate collected in each cycle, the abnormal factors at the time of collection in each cycle are calculated. Calculate the average value among all abnormal factors within the second preset time period, and use the average value as the abnormal factor for comparison with a preset threshold range.

9. The method according to claim 1, wherein the abnormal EGR flow includes excessively high EGR flow and / or excessively low EGR flow; The control of the EGR valve located in the EGR line to a third target opening degree for diagnostic purposes includes at least one of the following: To diagnose abnormalities such as excessive EGR flow, shut off the EGR valve located in the EGR pipeline; To diagnose abnormalities such as low EGR flow, control the EGR valve located in the EGR pipeline to its maximum opening.

10. A diagnostic device for EGR flow anomalies, the device comprising: The adjustment unit controls the mixing valve located in the intake manifold to a first target opening for diagnostics, controls the throttle valve located in the intake manifold to a second target opening for diagnostics, and controls the EGR valve located in the EGR line to a third target opening for diagnostics, so as to allow a portion of the ERG flow from the engine outlet to enter the intake manifold connected to the engine intake via the EGR line. The acquisition unit acquires the real-time pressure value collected by the pressure sensor located downstream of the EGR pipeline; The diagnostic unit compares the real-time pressure value with a preset pressure range to determine whether there is an abnormal EGR flow. The preset pressure range is a pre-calibrated range of pressure values ​​collected by the pressure sensor downstream of the EGR pipeline when the mixing valve is at the first target opening, the throttle valve is at the second target opening, and the EGR valve is at the third target opening and the EGR flow is normal.

11. An engine controller, comprising: processor; Memory used to store processor-executable instructions; The processor implements the method as described in any one of claims 1-9 by executing the executable instructions.

12. A vehicle having the engine controller of claim 11.

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