Fault determination method and device for post-processing system, equipment and storage medium

Abstract

The invention discloses a fault determination method, device and equipment for an after-treatment system and a storage medium, and the method comprises the steps: determining whether to diagnose the after-treatment system or not according to the obtained vehicle speed, engine speed, urea concentration ratio and operation duration of a vehicle; if it is determined that the post-processing system is diagnosed, whether the post-processing system is abnormal or not is determined according to the obtained diagnosis information; if it is determined that the post-processing system is abnormal, fault information of the post-processing system is determined according to target diagnosis information, and the fault information comprises shielding of the post-processing system, shielding of an NOx sensor, shielding of a temperature sensor, shielding of urea injection, less injection of urea, shielding of less injection of urea and shielding of a controller and shielding of a fault code; the technical problem that the fault information of the post-processing system cannot be determined due to the fact that the existing fault monitoring of the post-processing system is low in efficiency and the fault monitoring is avoided is solved, the abnormal vehicle can be quickly identified, and the fault information can be automatically diagnosed.

Description

Technical Field

[0001] The present application relates to the field of vehicle detection technology, and in particular to a method, device, equipment and computer-readable storage medium for determining a fault of a post-processing system. Background Art

[0002] With the upcoming implementation of the National VI emission regulations, diesel engine manufacturers are currently developing National VI diesel engines. In order to reduce NOx and particulate emissions in the engine exhaust, National VI diesel engines are equipped with a post-treatment system of catalytic oxidizer (DOC) + particulate filter (DPF) + selective oxidation reducer (SCR).

[0003] Whether it is the National IV, National V or National VI regulations, they all require an alarm when exhaust NOx emissions exceed the regulatory limit, and the vehicle will be limited in torque and speed when NOx emissions are too high. In order to save urea costs, some truck drivers have taken measures to shield the after-treatment system. Common shielding methods include full shielding and semi-shielding. Full shielding is to rewrite the engine computer version ECU so that the after-treatment does not spray urea to avoid vehicle speed and torque limit failures. Semi-shielding is to reduce urea consumption, for example, by adding a nut to the urea exhaust temperature sensor to reduce urea injection. However, shielding the after-treatment system will cause the nitrogen oxides in the exhaust gas to be unable to be effectively treated, resulting in excessive exhaust emissions. NOx can irritate the respiratory tract and cause bronchitis or emphysema. Long-term exposure may also increase the risk of cancer. At the same time, it will also cause environmental problems such as photochemical smog, acid rain and ozone layer damage. Therefore, it is very important to monitor the status of the after-treatment system. It is necessary to understand the status of the after-treatment in real time to ensure that the after-treatment system works normally and the exhaust emissions meet regulatory requirements.

[0004] There are currently two main methods for monitoring exhaust emissions. The first method is through fault monitoring. If the emissions exceed the regulatory limit, the SCR low efficiency fault will be reported; the second method is to have the environmental protection department randomly inspect vehicles and install PEMS equipment on the vehicle to conduct vehicle tests to confirm whether the exhaust emissions meet the requirements. However, the fault monitoring method is easy to be cracked, such as by shielding fault codes, modifying sensor measurement results, or modifying emission limits. The whole vehicle test method is too expensive and has too low coverage. It takes about a week to conduct a whole vehicle inspection, which is costly and time-consuming. In addition, the random inspection of vehicles will also encounter the problem of driver non-cooperation. Therefore, the existing fault monitoring of the post-processing system has the problems of low efficiency and avoidance of fault monitoring, resulting in the inability to determine the fault information of the post-processing system. Summary of the invention

[0005] The present application provides a post-processing system fault determination method, device, equipment and computer-readable storage medium, which can solve the problems of low efficiency and avoidance of fault monitoring of the post-processing system in the prior art, resulting in the technical problem that the fault information of the post-processing system cannot be determined.

[0006] In a first aspect, an embodiment of the present application provides a method for determining a fault of a post-processing system, the method for determining a fault of a post-processing system comprising:

[0007] Determine whether to diagnose the post-treatment system according to the vehicle speed, engine speed, urea concentration ratio and running time obtained;

[0008] If it is determined to diagnose the post-processing system, determining whether the post-processing system has an abnormality according to the acquired diagnostic information;

[0009] If it is determined that the post-processing system is abnormal, the fault information of the post-processing system is determined according to the target diagnostic information, wherein the fault information includes shielding the post-processing system, shielding NO x Sensor, shield temperature sensor, shield urea injection, less urea injection, shield urea less injection + shield controller, shield fault code.

[0010] In combination with the first aspect, in one implementation, determining whether the post-processing system has an abnormality according to the acquired diagnostic information includes:

[0011] The diagnostic information obtained is NO. x Sensor measurement value, post NO x Sensor measurement value, SCR inlet temperature value, urea injection value, post-NO x Sensor emission ratio and post NO x The conversion efficiency value of the sensor;

[0012] According to the former NO x The measured value of the sensor, the post NO x The measured value of the sensor, the SCR inlet temperature value, the urea injection value, the post-NO x The emission ratio of the sensor and the post-NO x The conversion efficiency value of the sensor determines whether there is an abnormality in the post-processing system.

[0013] In combination with the first aspect, in one implementation, determining the fault information of the post-processing system according to the target diagnostic information includes:

[0014] If the target diagnostic information obtained includes the previous NO x Sensor measurement value, post NO xThe sensor's measured value and the SCR inlet temperature value are then x The measured value of the sensor, the post NO x The measured value of the sensor and the SCR inlet temperature value are used to determine the fault information of the post-treatment system;

[0015] If the previous NO x The sensor's measured value and the post-NO x If the measured value of the sensor is greater than a first preset measured value or less than or equal to a second preset measured value within a first preset time period, and the SCR inlet temperature value is greater than a first preset temperature value or less than or equal to a second preset temperature value within the first preset time period, it is determined that the fault information of the post-processing system is shielding the post-processing system;

[0016] If the previous NO x The sensor's measured value and the post-NO x If the measured value of the sensor is greater than the first preset measured value or less than or equal to the second preset measured value within the first preset time, and the SCR inlet temperature value is greater than the third preset temperature value or less than the fourth preset temperature value within the second preset time, then the fault information of the post-treatment system is determined to be shielded NO x sensor;

[0017] If the previous NO x The sensor's measured value and the post-NO x If the measured value of the sensor is within the first preset measured value range within the second preset time period, and the SCR inlet temperature value is less than the fifth preset temperature value within the first preset time period, it is determined that the fault information of the post-processing system is a shielded temperature sensor.

[0018] In combination with the first aspect, in one implementation, determining the fault information of the post-processing system according to the target diagnostic information includes:

[0019] If the target diagnostic information obtained includes the previous NO x Sensor measurement value, post NO x The sensor's measured value, SCR inlet temperature value and urea injection value are then calculated based on the front NO x The measured value of the sensor, the post NO x The measured value of the sensor, the SCR inlet temperature value and the urea injection value are used to determine the fault information of the post-treatment system;

[0020] If the previous NO x The sensor's measured value and the post-NO xIf the measured value of the sensor is within the first preset measured value range within the second preset time length, and the SCR inlet temperature value is greater than the third preset temperature value or less than the fourth preset temperature value within the second preset time length, and the urea injection value is zero, it is determined that the fault information of the post-treatment system is shielding urea injection;

[0021] If the previous NO x The sensor's measured value and the post-NO x If the measurement value of the sensor is within the first preset measurement value range within the second preset time length, and the SCR inlet temperature value is greater than the third preset temperature value or less than or equal to the fourth preset temperature value within the second preset time length, and the maximum value of the urea injection value within the third preset time length is less than the first preset injection value, it is determined that the fault information of the post-treatment system is insufficient urea injection.

[0022] In combination with the first aspect, in one implementation, determining the fault information of the post-processing system according to the target diagnostic information includes:

[0023] If the target diagnostic result obtained is a urea liquid level change value, determining fault information of the post-treatment system according to the urea liquid level change value;

[0024] If the urea liquid level change value is less than the preset change value, it is determined that the fault information of the post-treatment system is shielding urea insufficient injection + shielding controller.

[0025] In combination with the first aspect, in one implementation, determining the fault information of the post-processing system according to the target diagnostic information includes:

[0026] If the target diagnostic information obtained includes the previous NO x Sensor measurement value, post NO x Sensor measurements, SCR inlet temperature, urea injection and post-NO x The emission ratio of the sensor is then based on the former NO x The measured value of the sensor, the post NO x The measured value of the sensor, the SCR inlet temperature value, the urea injection value and the post NO x an emission ratio of a sensor, determining fault information of the aftertreatment system;

[0027] If the previous NO x The sensor's measured value and the post-NO xThe measured value of the sensor is within the first preset measured value range within the second preset time length, and the SCR inlet temperature value is greater than the third preset temperature value or less than or equal to the fourth preset temperature value within the second preset time length, and the maximum value of the urea injection value within the third preset time length is greater than the first preset injection value, and the post NO x If the emission ratio of the sensor is greater than the preset emission ratio within the second preset time period, it is determined that the fault information of the post-processing system is a masked fault code.

[0028] In combination with the first aspect, in one embodiment, after determining whether to diagnose the post-treatment system according to the vehicle speed, engine speed, urea concentration ratio and running time obtained, the method further includes:

[0029] Obtain vehicle speed, engine speed, urea concentration ratio and running time;

[0030] If the vehicle speed is greater than a preset vehicle speed, the engine speed is greater than a preset speed, the urea concentration is greater than a preset concentration, and the running time is greater than a preset time, it is determined to diagnose the post-treatment system.

[0031] In a second aspect, an embodiment of the present application provides a fault determination device for a post-processing system, wherein the fault determination device for the post-processing system comprises:

[0032] A first determination module is used to determine whether to diagnose the post-treatment system according to the acquired vehicle speed, engine speed, urea concentration ratio and running time;

[0033] A second determination module, configured to determine whether the post-processing system has an abnormality according to the acquired diagnosis information if it is determined to diagnose the post-processing system;

[0034] The third determination module is used to determine the fault information of the post-processing system according to the target diagnostic information if it is determined that the post-processing system is abnormal, wherein the fault information includes shielding the post-processing system, shielding NO x Sensor, shield temperature sensor, shield urea injection, less urea injection, shield urea less injection + shield controller, shield fault code.

[0035] In a third aspect, an embodiment of the present application provides a post-processing system fault determination device, the post-processing system fault determination device comprising a processor, a memory, and a post-processing system fault determination program stored in the memory and executable by the processor, wherein when the post-processing system fault determination program is executed by the processor, the steps of the post-processing system fault determination method as described above are implemented.

[0036] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which a fault determination program for a post-processing system is stored, wherein when the fault determination program for the post-processing system is executed by a processor, the steps of the fault determination method for the post-processing system as described above are implemented.

[0037] The beneficial effects brought by the technical solution provided by the embodiments of the present application include:

[0038] By obtaining the vehicle speed, engine speed, urea concentration ratio and running time, determining whether to diagnose the post-processing system; if it is determined to diagnose the post-processing system, determining whether the post-processing system is abnormal according to the obtained diagnostic information; if it is determined that the post-processing system is abnormal, determining the fault information of the post-processing system according to the target diagnostic information, wherein the fault information includes shielding the post-processing system, shielding NO x Sensors, shielded temperature sensors, shielded urea injection, under-injection of urea, shielded under-injection of urea + shielded controller, and shielded fault codes solve the problems of low efficiency and avoidance of fault monitoring of the existing post-processing system, which leads to the technical problem of being unable to determine the fault information of the post-processing system, and realize rapid identification of abnormal vehicles and automatic diagnosis of fault information. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a flow chart of a first embodiment of a method for determining a fault of a post-processing system of the present application;

[0040] Figure 2 For this application Figure 1 Detailed flow chart of step S30;

[0041] Figure 3 For this application Figure 1 Detailed flow chart of step S30;

[0042] Figure 4 This is a functional module diagram of an embodiment of a fault determination device for a post-processing system of the present application;

[0043] Figure 5 This is a schematic diagram of the hardware structure of a fault determination device of a post-processing system involved in an embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] First, some technical terms in the present application are explained to facilitate those skilled in the art to understand the present application.

[0046] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0047] In a first aspect, an embodiment of the present application provides a method for determining a fault of a post-processing system.

[0048] In one embodiment, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the method for determining a fault in a post-processing system of the present application. Figure 1 As shown, the fault determination method of the post-processing system includes:

[0049] Step S10: determining whether to diagnose the post-treatment system according to the acquired vehicle speed, engine speed, urea concentration ratio and running time;

[0050] Exemplarily, the current vehicle speed, engine speed, urea concentration and running time of the vehicle are obtained, and the obtained vehicle speed, engine speed, urea concentration and running time are compared with the preset threshold value to determine whether to diagnose the post-processing system, and the preset threshold value includes the preset vehicle speed, the preset engine speed, the preset urea concentration and the preset running time. If the vehicle speed is greater than the preset vehicle speed of 20km / h, the engine speed is greater than the preset engine speed of 600rpm, the urea concentration is greater than the preset urea concentration of 30%, and the running time is greater than the preset running time of 30min, it is determined that the post-processing system is diagnosed. If the vehicle speed is less than or equal to the preset vehicle speed of 20km / h, the engine speed is less than or equal to the preset engine speed of 600rpm, the urea concentration is less than or equal to the preset urea concentration of 30%, or the running time is less than or equal to the preset running time of 30min, it is determined not to diagnose the post-processing system.

[0051] Step S20: if it is determined to diagnose the post-processing system, determining whether the post-processing system has an abnormality according to the acquired diagnostic information;

[0052] Exemplarily, diagnostic information is obtained, the diagnostic information including the front NO xSensor measurement value, post NO x Sensor measurement value, SCR inlet temperature value, urea injection value, post-NO x Sensor emission ratio and post NO x The conversion efficiency value of the sensor is obtained by x Sensor measurement value, post NO x Sensor measurement value, SCR inlet temperature value, urea injection value, post-NO x Sensor emission ratio and post NO x The conversion efficiency value of the sensor determines whether there is an abnormality in the post-processing system.

[0053] For example, if the previous NO x The sensor's measured value and the post-NO x If the sensor's measurement value is within the first preset measurement value range of 0 to 3000ppm within 60% of the second preset time, the SCR inlet temperature is greater than the first preset temperature value by 100°C or less than the second preset temperature value by 1500°C within 60% of the second preset time, the maximum value of the urea injection amount within 80% of the third preset time is greater than the first preset urea injection amount of 300mg / s, the post-NOx specific emission is less than the preset emission ratio of 1.44g / kwh outside the third preset time of 80% and the conversion efficiency is greater than the preset conversion efficiency of 85%, then it is determined that there is no abnormality in the post-treatment system. If the front NO x The sensor's measured value and the post-NO x If the measured value of the sensor is not within the first preset measured value range of 0 to 3000ppm within 60% of the second preset time, the SCR inlet temperature is less than the first preset temperature value by 100°C or greater than the second preset temperature value by 1500°C within 60% of the second preset time, the maximum value of the urea injection amount within 80% of the third preset time is less than the first preset urea injection amount of 300mg / s, the post-NOx specific emission is greater than the preset emission ratio of 1.44g / kwh outside 80% of the third preset time and the conversion efficiency is less than the preset conversion efficiency of 85%, it is determined that there is an abnormality in the post-treatment system.

[0054] After getting NO xThe emission ratio of the sensor includes a calculation window for each operating point. The right boundary of the calculation window is the current operating point. Starting from the current operating point, the work of the operating points is accumulated until the accumulated work is greater than or equal to the set value. The left boundary of the calculation window is defined, thereby determining the calculation window. Data is removed and filtered for the determined calculation window. Data removal: If the power of the operating point is continuously less than 10KW for more than 20s, then all the operating points of this period and the 10s before and after are removed from the window. Data filtering: If the power of the operating point in the window is continuously less than 10kw for a period of time greater than 60% of the calculation window, the calculation window will not be calculated. NO based on calculation window x Calculation method for emissions, NO x Emissions are calculated as window NO x The ratio of mass flow rate to window power, window NO x Mass flow is NO for all conditions x The mass flow is summed, and the power of the window is the power of all working conditions. After that, NO x Emission ratio of the sensor.

[0055] After getting NO x The conversion efficiency value of the sensor includes two methods, long and short working conditions, to confirm the stable working condition, thus supporting the accurate conversion efficiency. The long working condition is to consider the influence of the time lag signal. The main parameters include DOC temperature, DPF temperature, SCR temperature, post NO x The main parameters of short-term operation include the front NO x , urea injection amount, exhaust gas flow, speed and torque percentage. The long working condition selects a longer working condition window, such as selecting a 1h working condition point, and the short working condition selects a shorter working condition window, such as selecting a 10-minute working condition point. If both the long working condition and the short working condition meet the requirements of the steady-state working condition, the short working condition is selected to calculate the conversion efficiency.

[0056] Steady-state judgment of long-term operating conditions: Calculate the average value of the long-term operating condition, calculate the difference between each value in the long-term operating condition and the average value, if the absolute value of the difference between 80% of the operating points is less than 10% of the average value (DOC temperature, DPF temperature, SCR temperature and post-NO x The conversion efficiency calculation method for long-term operation is η = (NO before the long-term operation window x Specific emissions - NO after long operating window x Specific emission) / NO before long working window x Specific emissions.

[0057] Steady-state judgment of short working condition: calculate the average value of short working condition, calculate the difference between each value in long working condition and the average value, if the absolute value of the difference between 80% of the working condition points is less than 5% of the average value (before NOx , urea injection amount, exhaust gas flow, speed and torque percentage must all be met), then it indicates that the operating condition is a steady-state condition. The conversion efficiency calculation method for short operating conditions is η = (NO x Specific emission-NO after short operating window x Specific emission) / NO before short working window x Specific emissions.

[0058] Step S30: If it is determined that the post-processing system is abnormal, the fault information of the post-processing system is determined according to the target diagnostic information, wherein the fault information includes shielding the post-processing system, shielding NO x Sensor, shield temperature sensor, shield urea injection, less urea injection, shield urea less injection + shield controller, shield fault code.

[0059] Exemplarily, the target diagnostic information includes the former NO x Sensor measurement value, post NO x Sensor measurements, SCR inlet temperature, urea injection and post-NO x Emissions from the sensor, through the front NO x Sensor measurement value, post NO x Sensor measurements, SCR inlet temperature, urea injection and post-NO x The emission of the sensor determines the fault information of the post-processing system, wherein the fault information includes shielding the post-processing system, shielding NO x Sensor, shield temperature sensor, shield urea injection, less urea injection, shield urea less injection + shield controller, shield fault code.

[0060] Specifically, determining the fault information of the post-treatment system according to the target diagnostic information includes: if the target diagnostic result obtained is a urea liquid level change value, determining the fault information of the post-treatment system according to the urea liquid level change value; if the urea liquid level change value is less than a preset change value, determining that the fault information of the post-treatment system is shielding urea insufficient injection + shielding the controller.

[0061] Exemplarily, the urea liquid level is filtered Yn=0.1*Xn+0.9*Yn-1, where Yn is the current filtered liquid level, Xn is the liquid level measured by the current sensor, and Yn-1 is the filtered liquid level at the previous moment. The liquid level change per second Δa is calculated as the liquid level after filtering at the previous moment minus the current filtered liquid level. If the liquid level change is less than or equal to 0, it is unified as 0. When the vehicle's mileage S is greater than 500km and no urea is added, it is judged that ΔLm<S*B / 100*C*D / V, where ΔLm is the urea liquid level change, V is the urea tank volume, ranging from 20 to 150L; B is the vehicle's fuel consumption per 100 kilometers, ranging from 0 to 100L / 100km; C is the urea-fuel ratio, ranging from 0.05 to 0.2; D is the limit value of urea spraying less, ranging from 0 to 1. If the urea liquid level change value is less than the preset change value, it is determined that the fault information of the post-treatment system is shielding urea insufficient injection + shielding controller.

[0062] Specifically, the step of determining the fault information of the post-processing system according to the target diagnostic information includes: if the acquired target diagnostic information includes the front NO x Sensor measurement value, post NO x Sensor measurements, SCR inlet temperature, urea injection and post-NO x The emission ratio of the sensor is then based on the former NO x The measured value of the sensor, the post NO x The measured value of the sensor, the SCR inlet temperature value, the x The sensor's measured value and the post-NO x The measured value of the sensor is within the first preset measured value range within the second preset time length, and the SCR inlet temperature value is greater than the third preset temperature value or less than or equal to the fourth preset temperature value within the second preset time length, and the maximum value of the urea injection value within the third preset time length is greater than the first preset injection value, and the post NO x If the emission ratio of the sensor is greater than the preset emission ratio within the second preset time period, it is determined that the fault information of the post-processing system is a masked fault code.

[0063] Demonstration, former NO x The sensor's measured value and the post-NO x The sensor's measured value is 0-3000ppm for 60% of the time, the SCR inlet temperature is greater than 100℃ and less than 1500℃ for 60% of the time, the maximum urea injection amount is greater than 300mg / s for 20% of the time, and the post-NO x More than 60% of the specific emissions are greater than 1.44g / kwh, and the fault information of the after-treatment system is determined to be a shielded fault code.

[0064] In this embodiment, it is determined whether to diagnose the post-processing system according to the vehicle speed, engine speed, urea concentration ratio and running time obtained by the vehicle; if it is determined to diagnose the post-processing system, it is determined whether the post-processing system is abnormal according to the obtained diagnostic information; if it is determined that the post-processing system is abnormal, the fault information of the post-processing system is determined according to the target diagnostic information, wherein the fault information includes shielding the post-processing system, shielding NO x Sensors, shielded temperature sensors, shielded urea injection, under-injection of urea, shielded under-injection of urea + shielded controller, and shielded fault codes solve the problems of low efficiency and avoidance of fault monitoring of the existing post-processing system, which leads to the technical problem of being unable to determine the fault information of the post-processing system, and realize rapid identification of abnormal vehicles and automatic diagnosis of fault information.

[0065] In one embodiment, referring to Figure 2 , Figure 2 For this application Figure 1 Detailed flow chart of step S30 in FIG. Figure 2 As shown, step S30 includes:

[0066] Step S31: If the acquired target diagnostic information includes the previous NO x Sensor measurement value, post NO x The sensor's measured value and the SCR inlet temperature value are then x The measured value of the sensor, the post NO x The measured value of the sensor and the SCR inlet temperature value are used to determine the fault information of the post-treatment system;

[0067] Step S32: If the previous NO x The sensor's measured value and the post-NO x If the measured value of the sensor is greater than a first preset measured value or less than or equal to a second preset measured value within a first preset time period, and the SCR inlet temperature value is greater than a first preset temperature value or less than or equal to a second preset temperature value within the first preset time period, it is determined that the fault information of the post-processing system is shielding the post-processing system;

[0068] Exemplarily, the measured values ​​of the front NOx sensor and the rear NOx sensor are greater than 3000 ppm or less than or equal to 0 ppm 90% of the time, and the SCR inlet temperature is greater than 1735° C. or less than or equal to 0° C. 90% of the time.

[0069] Step S33: If the previous NO x The sensor's measured value and the post-NO xIf the measured value of the sensor is greater than the first preset measured value or less than or equal to the second preset measured value within the first preset time, and the SCR inlet temperature value is greater than the third preset temperature value or less than the fourth preset temperature value within the second preset time, then the fault information of the post-treatment system is determined to be shielded NO x sensor;

[0070] Demonstration, former NO x Sensor and rear NO x If the sensor's measured value is greater than 3000ppm or less than or equal to 0ppm for 90% of the time, and the SCR inlet temperature is greater than 100℃ and less than 1500℃ for 60% of the time, the fault information of the post-treatment system is determined to be shielded NO x sensor.

[0071] Step S34: If the previous NO x The sensor's measured value and the post-NO x If the measured value of the sensor is within the first preset measured value range within the second preset time period, and the SCR inlet temperature value is less than the fifth preset temperature value within the first preset time period, it is determined that the fault information of the post-processing system is a shielded temperature sensor.

[0072] Demonstration, former NO x Sensor and rear NO x If the sensor's measurement value is between 0 and 3000 ppm for 60% of the time and the SCR inlet temperature is always less than 180° C. for 90% of the time, it is determined that the fault information of the post-treatment system is the shielded temperature sensor.

[0073] In this embodiment, according to the front NO x The measured value of the sensor, the post NO x The fault information of the post-processing system is determined based on the measured value of the sensor and the SCR inlet temperature value, thereby solving the technical problem that the fault information of the post-processing system cannot be determined in the related art.

[0074] In one embodiment, referring to Figure 3 , Figure 3 For this application Figure 1 Detailed flow chart of step S30 in FIG. Figure 3 As shown, step S30 includes:

[0075] Step S35: If the acquired target diagnostic information includes the previous NO x Sensor measurement value, post NO x The sensor's measured value, SCR inlet temperature value and urea injection value are then calculated based on the front NO x The measured value of the sensor, the post NO xThe measured value of the sensor, the SCR inlet temperature value and the urea injection value are used to determine the fault information of the post-treatment system;

[0076] Step S36: If the previous NO x The sensor's measured value and the post-NO x If the measured value of the sensor is within the first preset measured value range within the second preset time length, and the SCR inlet temperature value is greater than the third preset temperature value or less than the fourth preset temperature value within the second preset time length, and the urea injection value is zero, it is determined that the fault information of the post-treatment system is shielding urea injection;

[0077] Demonstration, former NO x Sensor and rear NO x The sensor's measurement value is 0-3000ppm for 60% of the time, the SCR inlet temperature is greater than 100°C and less than 1500°C for 60% of the time, the urea injection amount is 0, and it is determined that the fault information of the post-treatment system is shielded urea injection.

[0078] Step S37: If the previous NO x The sensor's measured value and the post-NO x If the measurement value of the sensor is within the first preset measurement value range within the second preset time length, and the SCR inlet temperature value is greater than the third preset temperature value or less than or equal to the fourth preset temperature value within the second preset time length, and the maximum value of the urea injection value within the third preset time length is less than the first preset injection value, it is determined that the fault information of the post-treatment system is insufficient urea injection.

[0079] Demonstration, former NO x Sensor and rear NO x If the sensor's measurement value is 0-3000ppm for 60% of the time, the SCR inlet temperature is greater than 100℃ and less than 1500℃ for 60% of the time, and the maximum value of the urea injection amount is less than 300mg / s for 95% of the time, then the fault information of the post-treatment system is determined to be insufficient urea injection.

[0080] In this embodiment, according to the previous NO x Sensor measurement value, post NO x The sensor's measured value, SCR inlet temperature value and urea injection value are used to determine the fault information of the post-treatment system, solving the technical problem that the fault information of the post-treatment system cannot be determined in the related art.

[0081] In a second aspect, an embodiment of the present application also provides a fault determination device for a post-processing system.

[0082] In one embodiment, referring to Figure 4 , Figure 4This is a functional module diagram of an embodiment of a fault determination device for a post-processing system of the present application. Figure 4 As shown, the fault determination device of the post-processing system includes:

[0083] A first determination module 10 is used to determine whether to diagnose the post-treatment system according to the acquired vehicle speed, engine speed, urea concentration ratio and running time;

[0084] A second determination module 20 is used to determine whether there is an abnormality in the post-processing system according to the acquired diagnostic information if it is determined to diagnose the post-processing system;

[0085] The third determination module 30 is used to determine the fault information of the post-processing system according to the target diagnostic information if it is determined that the post-processing system is abnormal, wherein the fault information includes shielding the post-processing system, shielding NO x Sensor, shield temperature sensor, shield urea injection, less urea injection, shield urea less injection + shield controller, shield fault code.

[0086] Furthermore, in one embodiment, the second determining module 20 is used to:

[0087] The diagnostic information obtained is NO. x Sensor measurement value, post NO x Sensor measurement value, SCR inlet temperature value, urea injection value, post-NO x Sensor emission ratio and post NO x The conversion efficiency value of the sensor;

[0088] According to the former NO x The measured value of the sensor, the post NO x The measured value of the sensor, the SCR inlet temperature value, the urea injection value, the post-NO x The emission ratio of the sensor and the post-NO x The conversion efficiency value of the sensor determines whether there is an abnormality in the post-processing system.

[0089] Furthermore, in one embodiment, the third determining module 30 is used to:

[0090] If the target diagnostic information obtained includes the previous NO x Sensor measurement value, post NO x The sensor's measured value and the SCR inlet temperature value are then x The measured value of the sensor, the post NO x The measured value of the sensor and the SCR inlet temperature value are used to determine the fault information of the post-treatment system;

[0091] If the previous NOx The sensor's measured value and the post-NO x If the measured value of the sensor is greater than a first preset measured value or less than or equal to a second preset measured value within a first preset time period, and the SCR inlet temperature value is greater than a first preset temperature value or less than or equal to a second preset temperature value within the first preset time period, it is determined that the fault information of the post-processing system is shielding the post-processing system;

[0092] If the previous NO x The sensor's measured value and the post-NO x If the measured value of the sensor is greater than the first preset measured value or less than or equal to the second preset measured value within the first preset time length, and the SCR inlet temperature value is greater than the first preset temperature value or less than the third preset temperature value within the second preset time length, it is determined that the fault information of the post-treatment system is shielded NO x sensor;

[0093] If the previous NO x The sensor's measured value and the post-NO x If the measured value of the sensor is within the first preset measured value range within the second preset time period, and the SCR inlet temperature value is less than a fourth preset temperature value within the first preset time period, it is determined that the fault information of the post-processing system is a shielded temperature sensor.

[0094] Furthermore, in one embodiment, the second determining module 20 is used to:

[0095] If the target diagnostic information obtained includes the previous NO x Sensor measurement value, post NO x The sensor's measured value, SCR inlet temperature value and urea injection value are then calculated based on the front NO x The measured value of the sensor, the post NO x The measured value of the sensor, the SCR inlet temperature value and the urea injection value are used to determine the fault information of the post-treatment system;

[0096] If the previous NO x The sensor's measured value and the post-NO x If the measured value of the sensor is within the first preset measured value range within the second preset time length, and the SCR inlet temperature value is greater than the first preset temperature value or less than or equal to the second preset temperature value within the first preset time length, and the urea injection value is zero, it is determined that the fault information of the post-treatment system is shielding urea injection;

[0097] If the previous NO x The sensor's measured value and the post-NO xIf the measurement value of the sensor is within the first preset measurement value range within the second preset time length, and the SCR inlet temperature value is greater than the first preset temperature value or less than or equal to the second preset temperature value within the first preset time length, and the maximum value of the urea injection value within the first preset time length is less than the first preset injection value, it is determined that the fault information of the post-treatment system is insufficient urea injection.

[0098] Furthermore, in one embodiment, the second determining module 20 is used to:

[0099] If the target diagnostic result obtained is a urea liquid level change value, determining fault information of the post-treatment system according to the urea liquid level change value;

[0100] If the urea liquid level change value is less than the preset change value, it is determined that the fault information of the post-treatment system is shielding urea insufficient injection + shielding controller.

[0101] Furthermore, in one embodiment, the second determining module 20 is used to:

[0102] If the target diagnostic information obtained includes the previous NO x Sensor measurement value, post NO x Sensor measurements, SCR inlet temperature, urea injection and post-NO x The emission ratio of the sensor is then based on the former NO x The measured value of the sensor, the post NO x The measured value of the sensor, the SCR inlet temperature value, the urea injection value and the post NO x an emission ratio of a sensor, determining fault information of the aftertreatment system;

[0103] If the previous NO x The sensor's measured value and the post-NO x The measured value of the sensor is within the first preset measured value range within the second preset time length, and the SCR inlet temperature value is greater than the first preset temperature value or less than or equal to the second preset temperature value within the first preset time length, and the maximum value of the urea injection value within the second preset time length is greater than the first preset injection value, and the rear NO x If the emission ratio of the sensor is greater than the preset emission ratio within the second preset time period, it is determined that the fault information of the post-processing system is a masked fault code.

[0104] Furthermore, in one embodiment, the second determining module 20 is used to:

[0105] Obtain vehicle speed, engine speed, urea concentration ratio and running time;

[0106] If the vehicle speed is greater than a preset vehicle speed, the engine speed is greater than a preset speed, the urea concentration is greater than a preset concentration, and the running time is greater than a preset time, it is determined to diagnose the post-treatment system.

[0107] Among them, the functional implementation of each module in the above-mentioned fault determination device of the post-processing system corresponds to each step in the above-mentioned fault determination method embodiment of the post-processing system, and its functions and implementation processes are no longer repeated here one by one.

[0108] In a third aspect, an embodiment of the present application provides a fault determination device for a post-processing system, which may be a personal computer (PC), a laptop computer, a server, or other device having a data processing function.

[0109] Reference Figure 5 , Figure 5 Schematic diagram of the hardware structure of the fault determination device of the post-processing system involved in the embodiment of the present application. In the embodiment of the present application, the fault determination device of the post-processing system may include a processor, a memory, a communication interface and a communication bus.

[0110] The communication bus may be of any type and is used to interconnect the processor, the memory, and the communication interface.

[0111] The communication interface includes input / output (I / O) interfaces, physical interfaces, and logical interfaces, which are used to interconnect the components in the fault determination device of the post-processing system, and interfaces used to interconnect the fault determination device of the post-processing system with other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, an optical fiber interface, an ATM interface, etc.; the user device can be a display, a keyboard, etc.

[0112] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0113] The processor may be a general-purpose processor, and the general-purpose processor may call the fault determination program of the post-processing system stored in the memory, and execute the fault determination method of the post-processing system provided in the embodiment of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the fault determination program of the post-processing system is called may refer to the various embodiments of the fault determination method of the post-processing system of the present application, which will not be repeated here.

[0114] Those skilled in the art will understand that Figure 5 The hardware structure shown in the figure does not constitute a limitation on the present application, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0115] In a fourth aspect, an embodiment of the present application also provides a computer-readable storage medium.

[0116] The computer-readable storage medium of the present application stores a post-processing system fault determination program, wherein when the post-processing system fault determination program is executed by a processor, the steps of the post-processing system fault determination method as described above are implemented.

[0117] Among them, the method implemented when the fault determination program of the post-processing system is executed can refer to the various embodiments of the fault determination method of the post-processing system of the present application, and will not be repeated here.

[0118] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0119] The terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit "first", "second" and "third" to different types.

[0120] In the description of the embodiments of the present application, "exemplary", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a specific way.

[0121] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; the “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0122] In some processes described in the embodiments of the present application, multiple operations or steps that appear in a specific order are included, but it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or in parallel, and the sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0123] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, disk, CD) as described above, and includes a number of instructions for a terminal device to execute the methods described in each embodiment of the present application.

[0124] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for determining a fault of a post-processing system, characterized in that: The post-processing system fault determination method comprises: Determine whether to diagnose the post-treatment system according to the acquired vehicle speed, engine speed, urea concentration and running time; If it is determined to diagnose the post-processing system, determining whether the post-processing system has an abnormality according to the acquired diagnostic information; If it is determined that the post-processing system is abnormal, the fault information of the post-processing system is determined according to the target diagnostic information, wherein the fault information includes shielding the post-processing system, shielding NO x Sensor, shield temperature sensor, shield urea injection, less urea injection, shield urea less injection + shield controller, shield fault code.

2. The method for determining a fault of a post-processing system according to claim 1, wherein: Determining whether the post-processing system has an abnormality according to the acquired diagnostic information includes: The diagnostic information obtained is NO. x Sensor measurement value, post NO x Sensor measurement value, SCR inlet temperature value, urea injection value, post-NO x Sensor emission ratio and post NO x The conversion efficiency value of the sensor; According to the former NO x The measured value of the sensor, the post NO x The measured value of the sensor, the SCR inlet temperature value, the urea injection value, the post-NO x The emission ratio of the sensor and the post-NO x The conversion efficiency value of the sensor determines whether there is an abnormality in the post-processing system.

3. The method for determining a fault of a post-processing system according to claim 1, wherein: The determining, according to the target diagnostic information, the fault information of the post-processing system includes: If the target diagnostic information obtained includes the previous NO x Sensor measurement value, post NO x The sensor's measured value and the SCR inlet temperature value are then x The measured value of the sensor, the post NO x The measured value of the sensor and the SCR inlet temperature value are used to determine the fault information of the post-treatment system; If the previous NO x The sensor's measured value and the post-NO x If the measured value of the sensor is greater than a first preset measured value or less than or equal to a second preset measured value within a first preset time period, and the SCR inlet temperature value is greater than a first preset temperature value or less than or equal to a second preset temperature value within the first preset time period, it is determined that the fault information of the post-processing system is shielding the post-processing system; If the previous NO x The sensor's measured value and the post-NO x If the measured value of the sensor is greater than the first preset measured value or less than or equal to the second preset measured value within the first preset time, and the SCR inlet temperature value is greater than the third preset temperature value or less than the fourth preset temperature value within the second preset time, then the fault information of the post-treatment system is determined to be shielded NO x sensor; If the previous NO x The sensor's measured value and the post-NO x If the measured value of the sensor is within the first preset measured value range within the second preset time period, and the SCR inlet temperature value is less than the fifth preset temperature value within the first preset time period, it is determined that the fault information of the post-processing system is a shielded temperature sensor.

4. The method for determining a fault of a post-processing system according to claim 1, wherein: The determining, according to the target diagnostic information, the fault information of the post-processing system includes: If the target diagnostic information obtained includes the previous NO x Sensor measurement value, post NO x The sensor's measured value, SCR inlet temperature value and urea injection value are then calculated based on the front NO x The measured value of the sensor, the post NO x The measured value of the sensor, the SCR inlet temperature value and the urea injection value are used to determine the fault information of the post-treatment system; If the previous NO x The sensor's measured value and the post-NO x If the measured value of the sensor is within the first preset measured value range within the second preset time length, and the SCR inlet temperature value is greater than the third preset temperature value or less than the fourth preset temperature value within the second preset time length, and the urea injection value is zero, it is determined that the fault information of the post-treatment system is shielding urea injection; If the previous NO x The sensor's measured value and the post-NO x If the measurement value of the sensor is within the first preset measurement value range within the second preset time length, and the SCR inlet temperature value is greater than the third preset temperature value or less than or equal to the fourth preset temperature value within the second preset time length, and the maximum value of the urea injection value within the third preset time length is less than the first preset injection value, it is determined that the fault information of the post-treatment system is insufficient urea injection.

5. The method for determining a fault of a post-processing system according to claim 1, wherein: The determining, according to the target diagnostic information, the fault information of the post-processing system includes: If the target diagnostic result obtained is a urea liquid level change value, determining fault information of the post-treatment system according to the urea liquid level change value; If the urea liquid level change value is less than the preset change value, it is determined that the fault information of the post-treatment system is shielding urea insufficient injection + shielding controller.

6. The method for determining a fault of a post-processing system according to claim 1, wherein: The determining, according to the target diagnostic information, the fault information of the post-processing system includes: If the target diagnostic information obtained includes the previous NO x Sensor measurement value, post NO x Sensor measurements, SCR inlet temperature, urea injection and post-NO x The emission ratio of the sensor is then based on the former NO x The measured value of the sensor, the post NO x The measured value of the sensor, the SCR inlet temperature value, the urea injection value and the post NO x an emission ratio of a sensor, determining fault information of the aftertreatment system; If the previous NO x The sensor's measured value and the post-NO x The measured value of the sensor is within the first preset measured value range within the second preset time length, and the SCR inlet temperature value is greater than the third preset temperature value or less than or equal to the fourth preset temperature value within the second preset time length, and the maximum value of the urea injection value within the third preset time length is greater than the first preset injection value, and the post NO x If the emission ratio of the sensor is greater than the preset emission ratio within the second preset time period, it is determined that the fault information of the post-processing system is a masked fault code.

7. The post-processing system fault determination method according to claim 1, characterized in that: The determining to diagnose the post-processing system includes: Obtain vehicle speed, engine speed, urea concentration ratio and running time; If the vehicle speed is greater than a preset vehicle speed, the engine speed is greater than a preset speed, the urea concentration is greater than a preset concentration, and the running time is greater than a preset time, it is determined to diagnose the post-treatment system.

8. A post-processing system fault determination device, characterized in that: The fault determination device of the post-processing system comprises: A first determination module is used to determine whether to diagnose the post-treatment system according to the acquired vehicle speed, engine speed, urea concentration ratio and running time; A second determination module, configured to determine whether the post-processing system has an abnormality according to the acquired diagnosis information if it is determined to diagnose the post-processing system; The third determination module is used to determine the fault information of the post-processing system according to the target diagnostic information if it is determined that the post-processing system is abnormal, wherein the fault information includes shielding the post-processing system, shielding NO x Sensor, shield temperature sensor, shield urea injection, less urea injection, shield urea less injection + shield controller, shield fault code.

9. A post-processing system fault determination device, characterized in that: The post-processing system fault determination device includes a processor, a memory, and a post-processing system fault determination program stored in the memory and executable by the processor, wherein when the post-processing system fault determination program is executed by the processor, the steps of the post-processing system fault determination method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a post-processing system fault determination program, wherein when the post-processing system fault determination program is executed by a processor, the steps of the post-processing system fault determination method according to any one of claims 1 to 7 are implemented.

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