Method, device and vehicle for detecting position tampering fault of nitrogen and oxygen sensor

Abstract

The present application provides a method, a detection device and a vehicle for detecting a position tampering fault of a nitrogen oxide sensor. The method includes: when enabling conditions and stable operating conditions are met, calculating in real time the cumulative deviation rate of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor, the cumulative deviation rate being the difference between 1 and the cumulative ratio, the first measurement cumulative value being the cumulative value of the measurement value of the downstream nitrogen oxide sensor, and the second measurement cumulative value being the cumulative value of the measurement value of the upstream nitrogen oxide sensor; when the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, determining the current cumulative deviation rate to be a target cumulative deviation rate; determining whether the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault at least based on the size of the target cumulative deviation rate, thereby solving the problem of inaccurate position tampering fault detection of the upstream and downstream nitrogen oxide sensors of the SCR in the prior art.

Description

Technical Field

[0001] The present invention relates to the field of nitrogen oxide sensor fault detection, and in particular to a method, a detection device, a computer-readable storage medium, and a vehicle for detecting a position tampering fault in a nitrogen oxide sensor. Background Art

[0002] Market feedback remote monitoring results show that downstream NO x The signal was high, but no fault related to excessive emissions was reported. The troubleshooting results showed that this was caused by tampering with and swapping the positions of the upstream and downstream nitrogen oxide sensors of the SCR.

[0003] like Figure 1 As shown, in order to solve the problem of tampering and interchange of the positions of upstream and downstream nitrogen oxide sensors, the prior art first determines the detection release conditions. When conditions permit, that is, the upstream and downstream nitrogen oxide sensors are fault-free, and the speed, torque, load and urea injection amount are all within the corresponding range, the movement of the upstream and downstream nitrogen oxide sensor measurement values ​​is averaged to obtain a moving average value, and then the moving average values ​​of the upper and lower nitrogen oxide sensors are compared with the threshold values ​​respectively. The expected result is that the upstream nitrogen oxide moving average value is greater than a certain threshold value, and the downstream nitrogen oxide moving average value is less than a certain threshold value. If the upstream nitrogen oxide moving average value is not greater than the certain threshold value and the downstream nitrogen oxide moving average value is not less than the certain threshold value, a fault will be reported.

[0004] However, if Figure 2 As shown, Figure 2 The middle curve 1 is the relationship curve between the measured value of the downstream nitrogen oxide sensor and time. Figure 2 Curve 2 in the middle is the relationship curve between the measurement value of the upstream nitrogen oxide sensor and time. In actual use, it is found that the signal will still change greatly after the upstream and downstream nitrogen oxide sensors are swapped, and the conditions for the fault detection setting are not very reasonable, resulting in the fault may not be detected after the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are swapped.

[0005] The nitrogen oxide concentrations upstream and downstream are subject to the different emissions of each engine and are affected by the engine operating conditions, resulting in a large workload for calibration development and verification and increased product development costs. Summary of the Invention

[0006] The main purpose of this application is to provide a method, a detection device, a computer-readable storage medium and a vehicle for detecting a position tampering fault of a nitrogen oxide sensor, so as to at least solve the problem of inaccurate detection of position tampering faults of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor of the SCR in the prior art.

[0007] To achieve the above-mentioned purpose, according to one aspect of the present application, a method for detecting a position tampering fault of a nitrogen oxide sensor is provided, wherein an upstream nitrogen oxide sensor is arranged on an exhaust pipe connected to an inlet of an SCR system, and a downstream nitrogen oxide sensor is arranged on an exhaust pipe connected to an outlet of the SCR system, and the method comprises: under the condition that an enabling condition and a stable operating condition are satisfied, calculating in real time a cumulative deviation rate of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor, the cumulative deviation rate being the difference between 1 and a cumulative ratio, the cumulative ratio being the ratio of a first measurement cumulative value to a second measurement cumulative value, the first measurement cumulative value being the cumulative value of the measurement value of the downstream nitrogen oxide sensor, and the second measurement cumulative value being the cumulative value of the measurement value of the upstream nitrogen oxide sensor, the enabling condition being that the SCR system, the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are both connected. All oxygen sensors operate without faults, and the stable operating conditions are that the temperature and temperature change rate of the SCR system are respectively within the corresponding predetermined ranges, the flow rate of the exhaust gas is within the corresponding predetermined range, and the change rate of the flow rate of the exhaust gas is within the corresponding predetermined range; when the cumulative time reaches the predetermined time and / or the cumulative flow rate of the exhaust gas reaches the predetermined cumulative value, the current cumulative deviation rate is determined to be the target cumulative deviation rate, the cumulative time is the duration for satisfying the enabling condition and the stable operating condition, and the cumulative flow rate is the cumulative value of the instantaneous flow rate of the exhaust gas within the cumulative time; at least based on the size of the target cumulative deviation rate, it is determined whether the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault, and the position tampering fault is a fault caused by the interchange of positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

[0008] Optionally, when the cumulative time reaches a predetermined time and / or the cumulative flow of the exhaust gas reaches a predetermined cumulative value, before determining that the current cumulative deviation rate is the target cumulative deviation rate, the method also includes: when the enabling condition is not met, clearing the first measurement cumulative value and the second measurement cumulative value to zero; when the enabling condition is met and the stable operating condition is not met, freezing the first measurement cumulative value and the second measurement cumulative value until the stable operating condition is met.

[0009] Optionally, when the cumulative time reaches a predetermined time and / or the cumulative flow of the exhaust gas reaches a predetermined cumulative value, before determining that the current cumulative deviation rate is the target cumulative deviation rate, the method also includes: when the cumulative time is less than the predetermined time and the enabling condition is not met, clearing the first measurement cumulative value and the second measurement cumulative value; when the cumulative time is less than the predetermined time and the stable operating condition is not met, clearing the first measurement cumulative value and the second measurement cumulative value; when the cumulative time is greater than or equal to the predetermined time, the cumulative flow is less than the predetermined cumulative value and the enabling condition is not met, clearing the first measurement cumulative value and the second measurement cumulative value; when the cumulative time is greater than or equal to the predetermined time, the cumulative flow is less than the predetermined cumulative value and the enabling condition is not met, freezing the first measurement cumulative value and the second measurement cumulative value until the stable operating condition is met.

[0010] Optionally, whether the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault is determined at least based on the size of the target cumulative deviation rate, including: when the target cumulative deviation rate is less than a first calibration value, determining that the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault, and the first calibration value is greater than or equal to 0.

[0011] Optionally, determining whether the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault at least based on the size of the target cumulative deviation rate also includes: when the target cumulative deviation rate is greater than or equal to the first calibration value and less than a second calibration value, adding 1 to the number of errors and clearing the first measurement cumulative value and the second measurement cumulative value, and the second calibration value is greater than the first calibration value; when the target cumulative deviation rate is greater than or equal to the second calibration value, subtracting 1 from the number of errors and clearing the first measurement cumulative value and the second measurement cumulative value; when the number of errors is greater than a predetermined number, determining that the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault.

[0012] Optionally, when the target cumulative deviation rate is less than a first calibration value, determining that there is a position tampering fault in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor includes: when the target cumulative deviation rate is less than 0, determining that there is a position tampering fault in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

[0013] Optionally, the enabling conditions include the upstream nitrogen oxide sensor being fault-free, the downstream nitrogen oxide sensor being fault-free, the urea injection device being fault-free, and the exhaust gas of the SCR system meeting the NO xEmission standards, ambient temperature is within a predetermined temperature range, and ambient pressure is within a predetermined pressure range.

[0014] According to another aspect of the present application, a device for detecting a position tampering fault of a nitrogen oxide sensor is provided, wherein an upstream nitrogen oxide sensor is arranged on an exhaust pipe connected to an inlet of an SCR system, and a downstream nitrogen oxide sensor is arranged on an exhaust pipe connected to an outlet of the SCR system. The device includes: a calculation unit for calculating, in real time, a cumulative deviation rate of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor when an enabling condition and a stable operating condition are satisfied, wherein the cumulative deviation rate is a difference between 1 and a cumulative ratio, wherein the cumulative ratio is a ratio of a first measurement cumulative value to a second measurement cumulative value, wherein the first measurement cumulative value is a cumulative value of the measurement value of the downstream nitrogen oxide sensor, and the second measurement cumulative value is a cumulative value of the measurement value of the upstream nitrogen oxide sensor, and the enabling condition is that the SCR system, the upstream nitrogen oxide sensor, and the downstream nitrogen oxide sensor are all operating without faults. , the stable operating condition is that the temperature and temperature change rate of the SCR system are respectively within the corresponding predetermined ranges, the flow rate of the exhaust gas is within the corresponding predetermined range, and the change rate of the flow rate of the exhaust gas is within the corresponding predetermined range; a first determination unit is used to determine that the current cumulative deviation rate is a target cumulative deviation rate when the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, the cumulative time is the duration for satisfying the enabling condition and the stable operating condition, and the cumulative flow rate is the cumulative value of the instantaneous flow rate of the exhaust gas within the cumulative time; a second determination unit is used to determine whether there is a position tampering fault between the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor at least according to the size of the target cumulative deviation rate, and the position tampering fault is a fault caused by the interchange of positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

[0015] According to another aspect of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute any one of the methods.

[0016] According to another aspect of the present application, a processor is provided, wherein the processor is configured to run a program, wherein the program executes any one of the methods described when the program is run.

[0017] According to another aspect of the present application, a vehicle is provided, comprising: an SCR system, an upstream nitrogen oxide sensor, a downstream nitrogen oxide sensor, one or more processors, a memory, and one or more programs, wherein the upstream nitrogen oxide sensor is arranged on an exhaust pipe connected to an inlet of the SCR system, and the downstream nitrogen oxide sensor is arranged on an exhaust pipe connected to an outlet of the SCR system, the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include methods for executing any one of the methods described.

[0018] Applying the technical solution of the present application, in the detection method of the position tampering fault of the above-mentioned nitrogen oxide sensor, first, under the condition of meeting the enabling condition and stable operating condition, the cumulative deviation rate of the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor is calculated in real time, the above-mentioned cumulative deviation rate is the difference between 1 and the cumulative ratio, the above-mentioned cumulative ratio is the ratio of the first measurement cumulative value and the second measurement cumulative value, the above-mentioned first measurement cumulative value is the cumulative value of the measurement value of the above-mentioned downstream nitrogen oxide sensor, and the above-mentioned second measurement cumulative value is the cumulative value of the measurement value of the above-mentioned upstream nitrogen oxide sensor. The above-mentioned enabling condition is that the above-mentioned SCR system operates without fault, and the above-mentioned stable operating condition is that the temperature and temperature change rate of the above-mentioned SCR system are respectively within the corresponding predetermined ranges, and the exhaust gas The flow rate is within the corresponding predetermined range and the rate of change of the flow rate of the above-mentioned exhaust gas is within the corresponding predetermined range; then, when the cumulative time reaches the predetermined time and / or the cumulative flow rate of the above-mentioned exhaust gas reaches the predetermined cumulative value, the current above-mentioned cumulative deviation rate is determined to be the target cumulative deviation rate, the above-mentioned cumulative time is the duration of satisfying the above-mentioned enabling conditions and the above-mentioned stable operating conditions, and the above-mentioned cumulative flow rate is the cumulative value of the instantaneous flow rate of the above-mentioned exhaust gas within the above-mentioned cumulative time; finally, at least according to the size of the above-mentioned target cumulative deviation rate, it is determined whether the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor have a position tampering fault, and the above-mentioned position tampering fault is a fault caused by the interchange of the positions of the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor. In this method, when the SCR system is operating without fault under stable conditions, the upstream and downstream NO xThe concentration difference is obvious, and the cumulative deviation rate of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor is calculated in real time. When the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, it is determined that the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor is more representative, and the current cumulative deviation rate is used as the target cumulative deviation rate. Since the cumulative deviation rate is the difference between 1 and the cumulative ratio, where the cumulative ratio is the ratio of the cumulative value of the measurement value of the downstream nitrogen oxide sensor to the cumulative value of the measurement value of the upstream nitrogen oxide sensor, the smaller the cumulative deviation rate, the closer the cumulative value of the measurement value of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor, and the higher the probability that the position of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor is interchanged, it can be determined whether the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault based on the size of the cumulative deviation rate. This method only collects the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor when the SCR system is running without fault under stable conditions for cumulative deviation rate, to ensure that the upstream and downstream NO x The concentration difference is obvious, which greatly reduces the influence of working conditions on the measurement values ​​of upstream and downstream nitrogen oxide sensors, accurately detects position tampering faults, and solves the problem of inaccurate detection of position tampering faults of upstream and downstream nitrogen oxide sensors of SCR in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A flow chart of a method for detecting a position tampering fault of a nitrogen oxide sensor in the prior art is shown;

[0020] Figure 2 A graph showing the relationship between the measured value and time after the positions of the upstream and downstream nitrogen and oxygen sensors are tampered with in the prior art is shown;

[0021] Figure 3 A hardware structure block diagram of a mobile terminal for performing a method for detecting a position tampering fault of a nitrogen oxide sensor provided in an embodiment of the present application is shown;

[0022] Figure 4 A schematic flow chart of a method for detecting a position tampering fault of a nitrogen oxide sensor provided in accordance with an embodiment of the present application is shown;

[0023] Figure 5 A schematic flow chart of another method for detecting a position tampering fault of a nitrogen oxide sensor provided in accordance with an embodiment of the present application is shown;

[0024] Figure 6 A structural block diagram of a device for detecting position tampering failure of a nitrogen oxide sensor provided according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations 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 necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] For ease of description, some nouns or terms involved in the embodiments of the present application are explained below:

[0029] Diesel engine: An internal combustion engine that uses diesel as fuel and uses compression ignition.

[0030] NO x Original emission value: NO discharged into the exhaust pipe after combustion by the internal combustion engine, before post-processing catalytic conversion x concentration value.

[0031] NO x Tail emission value: NO is discharged into the exhaust pipe after combustion in the internal combustion engine and then converted into NO by post-processing catalysis. x concentration value.

[0032] As introduced in the background technology, the prior art does not accurately detect the position tampering fault of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor of the SCR. To solve this problem, the embodiments of the present application provide a method, a detection device, a computer-readable storage medium and a vehicle for detecting the position tampering fault of the nitrogen oxide sensor.

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0034] The method embodiments provided in the embodiments of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Taking running on a mobile terminal as an example, Figure 3 This is a hardware structure block diagram of a mobile terminal for detecting a position tampering fault of a nitrogen oxide sensor according to an embodiment of the present invention. Figure 3 As shown, the mobile terminal may include one or more ( Figure 3 Only one is shown) a processor 102 (the processor 102 may include but is not limited to a microprocessor MCU or a programmable logic device FPGA and other processing devices) and a memory 104 for storing data, wherein the mobile terminal may also include a transmission device 106 and an input and output device 108 for communication functions. It will be understood by those skilled in the art that Figure 3 The structure shown is only for illustration and does not limit the structure of the mobile terminal. Figure 3 More or fewer components than shown, or with Figure 3 Different configurations shown.

[0035] The memory 104 can be used to store computer programs, such as software programs and modules of application software, such as the computer program corresponding to the device information display method in the embodiment of the present invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, implementing the above-mentioned method. The memory 104 may include a high-speed random access memory and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the above-mentioned networks include but are not limited to the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the above-mentioned network may include a wireless network provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, abbreviated as NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0036] This embodiment provides a method for detecting a position tampering fault in a nitrogen oxide sensor, operating on a mobile terminal, a computer terminal, or a similar computing device. The upstream nitrogen oxide sensor is disposed in an exhaust pipe connected to the inlet of an SCR system, and the downstream nitrogen oxide sensor is disposed in an exhaust pipe connected to the outlet of the SCR system. It should be noted that the steps illustrated in the flowcharts of the accompanying drawings can be executed in a computer system, such as a set of computer-executable instructions. Furthermore, although the flowcharts illustrate a logical sequence, in some cases, the steps illustrated or described may be executed in a different order than that shown.

[0037] Figure 4 FIG. 1 is a flow chart of a method for detecting a position tampering fault of a nitrogen oxide sensor according to an embodiment of the present application. Figure 4 As shown, the method includes the following steps:

[0038] Step S201, when an enabling condition and a stable operating condition are met, calculating in real time the cumulative deviation rates of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor, the cumulative deviation rate being the difference between 1 and a cumulative ratio, the cumulative ratio being the ratio of a first measurement cumulative value to a second measurement cumulative value, the first measurement cumulative value being the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor, and the second measurement cumulative value being the cumulative value of the measurement values ​​of the upstream nitrogen oxide sensor, the enabling condition being that the SCR system, the upstream nitrogen oxide sensor, and the downstream nitrogen oxide sensor are all operating without fault, and the stable operating condition being that the temperature and temperature change rate of the SCR system are respectively within corresponding predetermined ranges, the flow rate of the exhaust gas is within a corresponding predetermined range, and the rate of change of the flow rate of the exhaust gas is within a corresponding predetermined range;

[0039] Specifically, when the SCR system operates without faults under stable operating conditions, it indicates that NO x The conversion efficiency is high, and the upstream and downstream NO x The concentration difference is obvious. The upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor measure once at a predetermined interval, for example, at an interval of 1s, the measurement values ​​of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are accumulated, and the cumulative deviation rate = 1-∑measurement value of the downstream nitrogen oxide sensor / ∑measurement value of the upstream nitrogen oxide sensor is calculated in real time.

[0040] Step S202: When the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, determining the current cumulative deviation rate as a target cumulative deviation rate, wherein the cumulative time is the duration of time during which the enabling condition and the stable operating condition are satisfied, and the cumulative flow rate is the cumulative value of the instantaneous flow rate of the exhaust gas within the cumulative time;

[0041] Specifically, if the cumulative time is lower than the predetermined time, or the cumulative flow of exhaust gas is lower than the predetermined cumulative value, the measurement values ​​of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are too few and not representative, and the chance of accidental detection is too high. When the cumulative time reaches the predetermined time and / or the cumulative flow of exhaust gas reaches the predetermined cumulative value, the accidental detection can be eliminated, and the current cumulative deviation rate can be used as the target cumulative deviation rate to judge the position tampering fault with higher accuracy.

[0042] Step S203, determining whether there is a position tampering fault in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor at least based on the size of the target cumulative deviation rate, where the position tampering fault is caused by the interchange of positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

[0043] Specifically, since the SCR system operates without failure under stable operating conditions, NO x The conversion efficiency is high, and the upstream and downstream NO x The concentration difference is obvious, however, the smaller the above-mentioned cumulative deviation rate is, the closer the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor is, and the higher the probability that the positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are interchanged. Therefore, it is possible to determine whether there is a position tampering fault in the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor based on the size of the above-mentioned target cumulative deviation rate.

[0044] In the above-mentioned method for detecting the position tampering fault of the nitrogen oxide sensor, first, under the condition that the enabling condition and the stable operating condition are met, the cumulative deviation rate of the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor is calculated in real time, the above-mentioned cumulative deviation rate is the difference between 1 and the cumulative ratio, the above-mentioned cumulative ratio is the ratio of the first measurement cumulative value and the second measurement cumulative value, the above-mentioned first measurement cumulative value is the cumulative value of the measurement value of the above-mentioned downstream nitrogen oxide sensor, and the above-mentioned second measurement cumulative value is the cumulative value of the measurement value of the above-mentioned upstream nitrogen oxide sensor. The above-mentioned enabling condition is that the above-mentioned SCR system operates without fault, and the above-mentioned stable operating condition is that the temperature and temperature change rate of the above-mentioned SCR system are respectively within the corresponding predetermined ranges, and the flow rate of the exhaust gas is within the corresponding range. The rate of change of the flow of the above-mentioned exhaust gas is within the corresponding predetermined range; then, when the cumulative time reaches the predetermined time and / or the cumulative flow of the above-mentioned exhaust gas reaches the predetermined cumulative value, the current cumulative deviation rate is determined to be the target cumulative deviation rate, the above-mentioned cumulative time is the duration of satisfying the above-mentioned enabling conditions and the above-mentioned stable operating conditions, and the above-mentioned cumulative flow is the cumulative value of the instantaneous flow of the above-mentioned exhaust gas within the above-mentioned cumulative time; finally, at least according to the size of the above-mentioned target cumulative deviation rate, it is determined whether the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor have a position tampering fault, and the above-mentioned position tampering fault is a fault caused by the interchange of the positions of the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor. In this method, when the SCR system is operating without fault under stable conditions, the upstream and downstream NO x The concentration difference is obvious, and the cumulative deviation rate of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor is calculated in real time. When the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, it is determined that the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor is more representative, and the current cumulative deviation rate is used as the target cumulative deviation rate. Since the cumulative deviation rate is the difference between 1 and the cumulative ratio, where the cumulative ratio is the ratio of the cumulative value of the measurement value of the downstream nitrogen oxide sensor to the cumulative value of the measurement value of the upstream nitrogen oxide sensor, the smaller the cumulative deviation rate, the closer the cumulative value of the measurement value of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor, and the higher the probability that the position of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor is interchanged, it can be determined whether the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault based on the size of the cumulative deviation rate. This method only collects the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor when the SCR system is running without fault under stable conditions for cumulative deviation rate, to ensure that the upstream and downstream NO x The concentration difference is obvious, which greatly reduces the influence of working conditions on the measurement values ​​of upstream and downstream nitrogen oxide sensors, accurately detects position tampering faults, and solves the problem of inaccurate detection of position tampering faults of upstream and downstream nitrogen oxide sensors of SCR in the prior art.

[0045] In order to further ensure the accuracy of fault detection, in an optional implementation, before step S202, the method further includes:

[0046] Step S301: if the enabling condition is not met, clear the first measurement cumulative value and the second measurement cumulative value;

[0047] Step S302 : When the enabling condition is met and the stable operating condition is not met, freezing the first measurement cumulative value and the second measurement cumulative value until the stable operating condition is met.

[0048] Specifically, when the enabling conditions are not met, the SCR system, the upstream NOx sensor or the downstream NOx sensor fails. For example, the upstream NOx sensor cannot output a valid NOx signal. x Concentration signal, the above SCR system currently has a fault prohibiting NO x Monitoring release, in this case, the measurement values ​​of the upstream NOx sensor or the downstream NOx sensor cannot be matched one to one, or NO x The conversion efficiency of NO is low, and the upstream and downstream NO x The concentration difference is not obvious, which makes it difficult to judge whether there is a tampering fault between the upstream NOx sensor and the downstream NOx sensor. Therefore, the first measurement cumulative value and the second measurement cumulative value are cleared and accumulated again. When the above enabling conditions are met and the above stable working conditions are not met, NOx x The conversion efficiency fluctuates greatly due to the influence of the operating conditions, resulting in large fluctuations in the measurement values ​​of the upstream nitrogen oxide sensor or the downstream nitrogen oxide sensor. Therefore, the first measurement cumulative value and the second measurement cumulative value are frozen until the stable operating conditions are met and then unfrozen and continued to accumulate, thereby improving the representativeness of the first measurement cumulative value and the second measurement cumulative value and further ensuring the accuracy of fault detection.

[0049] In order to further ensure the accuracy of fault detection, in an optional implementation, before step S202, the method further includes:

[0050] Step S401: if the accumulated time is less than the predetermined time and the enabling condition is not satisfied, clear the first measurement accumulated value and the second measurement accumulated value;

[0051] Step S402: if the accumulated time is less than the predetermined time and the stable working condition is not met, clearing the first measurement accumulated value and the second measurement accumulated value;

[0052] Step S403: if the accumulated time is greater than or equal to the predetermined time, the accumulated flow rate is less than the predetermined accumulated value, and the enabling condition is not satisfied, clearing the first measurement accumulated value and the second measurement accumulated value;

[0053] Step S404: When the accumulated time is greater than or equal to the predetermined time, the accumulated flow is less than the predetermined accumulated value, and the stable operating condition is not met, the first measurement accumulated value and the second measurement accumulated value are frozen until the stable operating condition is met.

[0054] Specifically, the calculation of the cumulative deviation rate is divided into two accumulation processes. When both the enabling condition and the stable operating condition are met, the predetermined time period is accumulated in advance. If the condition is still met, the second period is accumulated. When the cumulative flow reaches the predetermined cumulative value, the cumulative deviation rate of the upstream and downstream nitrogen oxide sensors is calculated using the formula. If the stable operating condition is not met when calculating the first cumulative value, the first measurement cumulative value and the second measurement cumulative value are reset to zero. When calculating the second cumulative value, the stable operating condition is not met, and the first measurement cumulative value and the second measurement cumulative value are frozen and not reset to zero. Whether calculating the first cumulative value or the second cumulative value, if the enabling condition is not met, the first measurement cumulative value and the second measurement cumulative value are reset to zero, thereby further ensuring the representativeness of the first measurement cumulative value and the second measurement cumulative value, and further ensuring the accuracy of fault detection.

[0055] In order to further ensure the accuracy of fault detection, in an optional implementation, the above step S203 includes:

[0056] Step S2031: When the target cumulative deviation rate is less than a first calibration value, it is determined that a position tampering fault exists in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor, and the first calibration value is greater than or equal to 0.

[0057] Specifically, by determining a suitable first calibration value through experimental calibration so that the target cumulative deviation rate is less than the first calibration value, it can be determined that there is a position tampering fault in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor. The larger the first calibration value, the lower the probability of the position tampering fault. The first calibration value is greater than or equal to 0 to ensure the sensitivity of fault detection.

[0058] In order to further ensure the accuracy of fault detection, in an optional implementation, the above step S203 further includes:

[0059] Step S2032: if the target cumulative deviation rate is greater than or equal to the first calibration value and less than the second calibration value, increment the number of errors by 1 and clear the first measurement cumulative value and the second measurement cumulative value, and the second calibration value is greater than the first calibration value;

[0060] Step S2033: if the target cumulative deviation rate is greater than or equal to the second calibration value, subtract 1 from the number of errors and clear the first measurement cumulative value and the second measurement cumulative value;

[0061] Step S2033: When the number of errors is greater than a predetermined number, it is determined that a position tampering fault exists in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

[0062] Specifically, the larger the above-mentioned first calibration value is, the lower the probability of position tampering failure is. However, when the above-mentioned target cumulative deviation rate is greater than or equal to the above-mentioned first calibration value, there is still a risk of position tampering failure. The second calibration value is determined through experimental calibration. If the above-mentioned target cumulative deviation rate is greater than the second calibration value, the probability of position tampering failure is low. The number of errors is reduced by 1. When the above-mentioned target cumulative deviation rate is greater than or equal to the above-mentioned first calibration value and less than the second calibration value, the probability of position tampering failure is high. The number of errors is increased by 1. Finally, if the number of errors is greater than the predetermined number, it can be determined that the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor have position tampering failures, which reduces the randomness and improves the accuracy of judgment.

[0063] In order to simplify the detection workload, in an optional implementation, the above step S2031 includes:

[0064] Step S20311: When the target cumulative deviation rate is less than 0, it is determined that there is a position tampering fault in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

[0065] Specifically, when the above-mentioned target cumulative deviation rate is less than 0, it indicates that the above-mentioned first measurement cumulative value is greater than the above-mentioned second measurement cumulative value, that is, the measurement value of the downstream nitrogen oxide sensor is higher than the measurement value of the upstream nitrogen oxide sensor as a whole. It can be directly determined that the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor have position tampering faults without the need to compare with the calibration value.

[0066] In order to further ensure the accuracy of fault detection, in an optional embodiment, the above-mentioned enabling conditions include that the above-mentioned upstream nitrogen oxide sensor is fault-free, the above-mentioned downstream nitrogen oxide sensor is fault-free, the urea injection device is fault-free, the exhaust of the above-mentioned SCR system meets the NOx emission standard, the ambient temperature is within a predetermined temperature range, and the ambient pressure is within a predetermined pressure range.

[0067] Specifically, the enabling condition judgment steps are as follows: 1) Upstream NO x Signal status: According to upstream NO x Whether the signal has a valid value is determined; 2) downstream NO x Signal status: According to downstream NO x 3) Urea injection status: Determine whether the urea is injected; 4) Ambient pressure status: whether the ambient pressure is valid; 5) Ambient temperature status: whether the ambient temperature is valid; 6) Whether the SCR system currently has a fault prohibition NO x Monitor and release; 7) NH3 storage level: Does the NH3 storage level meet the NO x Monitor the release requirements for the current hydrocarbon level: whether the current hydrocarbon level meets the NO x Monitoring release requirements, therefore, the above upstream nitrogen oxide sensor is fault-free, the above downstream nitrogen oxide sensor is fault-free, the urea injection device is fault-free, and the exhaust of the above SCR system meets NO x If the emission standards, the ambient temperature being within a predetermined temperature range, and the ambient pressure being within a predetermined pressure range are all met, it can be determined that the SCR system, the upstream nitrogen oxide sensor, and the downstream nitrogen oxide sensor are all operating without fault.

[0068] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the implementation process of the method for detecting the position tampering fault of the nitrogen oxide sensor of the present application will be described in detail below with reference to specific embodiments.

[0069] This embodiment relates to a specific method for detecting position tampering faults of nitrogen and oxygen sensors, such as Figure 5 As shown, the following steps are included:

[0070] Step S1: First, determine whether the enabling conditions and stable working conditions are met;

[0071] Step S2: starting two sections, when the accumulated time is less than the predetermined time and the enabling condition is not satisfied, clearing the first measurement accumulated value and the second measurement accumulated value; when the accumulated time is less than the predetermined time and the stable working condition is not satisfied, clearing the first measurement accumulated value and the second measurement accumulated value; when the accumulated time is greater than or equal to the predetermined time, the accumulated flow is less than the predetermined accumulated value and the enabling condition is not satisfied, clearing the first measurement accumulated value and the second measurement accumulated value; when the accumulated time is greater than or equal to the predetermined time, the accumulated flow is less than the predetermined accumulated value and the stable working condition is not satisfied, freezing the first measurement accumulated value and the second measurement accumulated value until the stable working condition is satisfied;

[0072] Step S3: calculating a cumulative deviation rate of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor, where the cumulative deviation rate is the difference between 1 and a cumulative ratio, where the cumulative ratio is the ratio of a first measurement cumulative value to a second measurement cumulative value, where the first measurement cumulative value is the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor, and the second measurement cumulative value is the cumulative value of the measurement values ​​of the upstream nitrogen oxide sensor, where the enabling condition is that the SCR system, the upstream nitrogen oxide sensor, and the downstream nitrogen oxide sensor are all operating without faults, and where the stable operating condition is that the temperature and temperature change rate of the SCR system are respectively within corresponding predetermined ranges, the flow rate of the exhaust gas is within the corresponding predetermined range, and the rate of change of the flow rate of the exhaust gas is within the corresponding predetermined range;

[0073] Step S4: When the cumulative deviation rate is less than the first calibration value, it is determined that the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault, and the first calibration value is greater than or equal to 0; when the target cumulative deviation rate is greater than or equal to the first calibration value and less than the second calibration value, the number of errors is increased by 1 and the first measurement cumulative value and the second measurement cumulative value are cleared, and the second calibration value is greater than the first calibration value; when the target cumulative deviation rate is greater than or equal to the second calibration value, the number of errors is reduced by 1 and the first measurement cumulative value and the second measurement cumulative value are cleared; when the number of errors is greater than the predetermined number, it is determined that the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault.

[0074] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0075] The embodiment of the present application also provides a device for detecting a position tampering fault of a nitrogen oxide sensor. It should be noted that the device for detecting a position tampering fault of a nitrogen oxide sensor according to the embodiment of the present application can be used to execute the method for detecting a position tampering fault of a nitrogen oxide sensor provided in the embodiment of the present application. The device is used to implement the above-mentioned embodiments and preferred implementations, and those that have been explained will not be repeated here. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and conceivable.

[0076] The following introduces a detection device for the position tampering failure of the nitrogen oxide sensor provided in an embodiment of the present application, wherein the upstream nitrogen oxide sensor is arranged on the exhaust pipe connected to the inlet of the SCR system, and the downstream nitrogen oxide sensor is arranged on the exhaust pipe connected to the outlet of the above-mentioned SCR system.

[0077] Figure 6 FIG is a schematic diagram of a device for detecting position tampering failure of a nitrogen oxide sensor according to an embodiment of the present application. Figure 6 As shown, the device includes:

[0078] a calculation unit 10 for calculating, in real time, a cumulative deviation rate of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor when an enabling condition and a stable operating condition are met, the cumulative deviation rate being the difference between 1 and a cumulative ratio, the cumulative ratio being the ratio of a first measurement cumulative value to a second measurement cumulative value, the first measurement cumulative value being the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor, and the second measurement cumulative value being the cumulative value of the measurement values ​​of the upstream nitrogen oxide sensor; the enabling condition being that the SCR system, the upstream nitrogen oxide sensor, and the downstream nitrogen oxide sensor are all operating without fault; and the stable operating condition being that the temperature and temperature change rate of the SCR system are respectively within corresponding predetermined ranges, the flow rate of the exhaust gas is within a corresponding predetermined range, and the rate of change of the flow rate of the exhaust gas is within a corresponding predetermined range;

[0079] Specifically, when the SCR system operates without faults under stable operating conditions, it indicates that NO x The conversion efficiency is high, and the upstream and downstream NO x The concentration difference is obvious. The upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor measure once at a predetermined interval, for example, at an interval of 1s, the measurement values ​​of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are accumulated, and the cumulative deviation rate = 1-∑measurement value of the downstream nitrogen oxide sensor / ∑measurement value of the upstream nitrogen oxide sensor is calculated in real time.

[0080] a first determining unit 20, configured to determine the current cumulative deviation rate as a target cumulative deviation rate when the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, wherein the cumulative time is the duration of time during which the enabling condition and the stable operating condition are satisfied, and the cumulative flow rate is the cumulative value of the instantaneous flow rate of the exhaust gas within the cumulative time;

[0081] Specifically, if the cumulative time is lower than the predetermined time, or the cumulative flow of exhaust gas is lower than the predetermined cumulative value, the measurement values ​​of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are too few and not representative, and the chance of accidental detection is too high. When the cumulative time reaches the predetermined time and / or the cumulative flow of exhaust gas reaches the predetermined cumulative value, the accidental detection can be eliminated, and the current cumulative deviation rate can be used as the target cumulative deviation rate to judge the position tampering fault with higher accuracy.

[0082] The second determination unit 30 is used to determine whether the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault based on at least the size of the target cumulative deviation rate, where the position tampering fault is a fault caused by the interchange of positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

[0083] Specifically, since the SCR system operates without failure under stable operating conditions, NO x The conversion efficiency is high, and the upstream and downstream NO x The concentration difference is obvious, however, the smaller the above-mentioned cumulative deviation rate is, the closer the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor is, and the higher the probability that the positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are interchanged. Therefore, it is possible to determine whether there is a position tampering fault in the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor based on the size of the above-mentioned target cumulative deviation rate.

[0084] In the detection device for the position tampering fault of the above-mentioned nitrogen oxide sensor, the calculation unit calculates the cumulative deviation rate of the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor in real time when the enabling condition and the stable operating condition are met. The above-mentioned cumulative deviation rate is the difference between 1 and the cumulative ratio. The above-mentioned cumulative ratio is the ratio of the first measurement cumulative value and the second measurement cumulative value. The above-mentioned first measurement cumulative value is the cumulative value of the measurement value of the above-mentioned downstream nitrogen oxide sensor, and the above-mentioned second measurement cumulative value is the cumulative value of the measurement value of the above-mentioned upstream nitrogen oxide sensor. The above-mentioned enabling condition is that the above-mentioned SCR system operates without fault, and the above-mentioned stable operating condition is that the temperature and temperature change rate of the above-mentioned SCR system are respectively within the corresponding predetermined ranges, and the flow rate of the exhaust gas is within the corresponding predetermined ranges. The first determination unit determines that the current cumulative deviation rate is the target cumulative deviation rate when the cumulative time reaches a predetermined time and / or the cumulative flow of the exhaust gas reaches a predetermined cumulative value. The cumulative time is the duration of time for satisfying the enabling conditions and the stable operating conditions. The cumulative flow is the cumulative value of the instantaneous flow of the exhaust gas within the cumulative time. The second determination unit determines whether there is a position tampering fault in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor at least based on the size of the target cumulative deviation rate. The position tampering fault is a fault caused by the interchange of the positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor. In this device, when the SCR system is operating without fault under stable conditions, the upstream and downstream NO x The concentration difference is obvious, and the cumulative deviation rate of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor is calculated in real time. When the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, it is determined that the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor is more representative, and the current cumulative deviation rate is used as the target cumulative deviation rate. Since the cumulative deviation rate is the difference between 1 and the cumulative ratio, where the cumulative ratio is the ratio of the cumulative value of the measurement value of the downstream nitrogen oxide sensor to the cumulative value of the measurement value of the upstream nitrogen oxide sensor, the smaller the cumulative deviation rate, the closer the cumulative value of the measurement value of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor, and the higher the probability that the position of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor is interchanged, it can be determined whether the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault based on the size of the cumulative deviation rate. This method only collects the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor when the SCR system is running without fault under stable conditions for cumulative deviation rate, to ensure that the upstream and downstream NO x The concentration difference is obvious, which greatly reduces the influence of working conditions on the measurement values ​​of upstream and downstream nitrogen oxide sensors, accurately detects position tampering faults, and solves the problem of inaccurate detection of position tampering faults of upstream and downstream nitrogen oxide sensors of SCR in the prior art.

[0085] In order to further ensure the accuracy of fault detection, in an optional embodiment, the above-mentioned device further includes:

[0086] a first processing unit, configured to, when the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, and before determining that the current cumulative deviation rate is a target cumulative deviation rate, clear the first measurement cumulative value and the second measurement cumulative value to zero if the enabling condition is not satisfied;

[0087] The second processing unit is configured to freeze the first measurement cumulative value and the second measurement cumulative value when the enabling condition is met and the stable operating condition is not met, until the stable operating condition is met.

[0088] Specifically, when the enabling conditions are not met, the SCR system, the upstream NOx sensor or the downstream NOx sensor fails. For example, the upstream NOx sensor cannot output a valid NOx signal. x Concentration signal, the above SCR system currently has a fault prohibiting NO x Monitoring release, in this case, the measurement values ​​of the upstream NOx sensor or the downstream NOx sensor cannot be matched one to one, or NO x The conversion efficiency of NO is low, and the upstream and downstream NO x The concentration difference is not obvious, which makes it difficult to judge whether there is a tampering fault between the upstream NOx sensor and the downstream NOx sensor. Therefore, the first measurement cumulative value and the second measurement cumulative value are cleared and accumulated again. When the above enabling conditions are met and the above stable working conditions are not met, NOx x The conversion efficiency fluctuates greatly due to the influence of the operating conditions, resulting in large fluctuations in the measurement values ​​of the upstream nitrogen oxide sensor or the downstream nitrogen oxide sensor. Therefore, the first measurement cumulative value and the second measurement cumulative value are frozen until the stable operating conditions are met and then unfrozen and continued to accumulate, thereby improving the representativeness of the first measurement cumulative value and the second measurement cumulative value and further ensuring the accuracy of fault detection.

[0089] In order to further ensure the accuracy of fault detection, in an optional embodiment, the above-mentioned device further includes:

[0090] a third processing unit, configured to, when the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, and before determining that the current cumulative deviation rate is the target cumulative deviation rate, clear the first measurement cumulative value and the second measurement cumulative value to zero if the cumulative time is less than the predetermined time and the enabling condition is not satisfied;

[0091] a fourth processing unit, configured to clear the first measurement cumulative value and the second measurement cumulative value to zero when the cumulative time is less than the predetermined time and the stable operating condition is not satisfied;

[0092] a fifth processing unit, configured to clear the first measurement cumulative value and the second measurement cumulative value to zero when the cumulative time is greater than or equal to the predetermined time, the cumulative flow is less than the predetermined cumulative value, and the enabling condition is not satisfied;

[0093] The sixth processing unit is used to freeze the first measurement cumulative value and the second measurement cumulative value when the above-mentioned cumulative time is greater than or equal to the above-mentioned predetermined time, the above-mentioned cumulative flow is less than the above-mentioned predetermined cumulative value, and the above-mentioned stable operating condition is not met, until the above-mentioned stable operating condition is met.

[0094] Specifically, the calculation of the cumulative deviation rate is divided into two accumulation processes. When both the enabling condition and the stable operating condition are met, the predetermined time period is accumulated in advance. If the condition is still met, the second period is accumulated. When the cumulative flow reaches the predetermined cumulative value, the cumulative deviation rate of the upstream and downstream nitrogen oxide sensors is calculated using the formula. If the stable operating condition is not met when calculating the first cumulative value, the first measurement cumulative value and the second measurement cumulative value are reset to zero. When calculating the second cumulative value, the stable operating condition is not met, and the first measurement cumulative value and the second measurement cumulative value are frozen and not reset to zero. Whether calculating the first cumulative value or the second cumulative value, if the enabling condition is not met, the first measurement cumulative value and the second measurement cumulative value are reset to zero, thereby further ensuring the representativeness of the first measurement cumulative value and the second measurement cumulative value, and further ensuring the accuracy of fault detection.

[0095] To further ensure the accuracy of fault detection, in an optional implementation, the second determining unit includes:

[0096] The first determination module is configured to determine that a position tampering fault exists in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor when the target cumulative deviation rate is less than a first calibration value, and the first calibration value is greater than or equal to 0.

[0097] Specifically, by determining a suitable first calibration value through experimental calibration so that the target cumulative deviation rate is less than the first calibration value, it can be determined that there is a position tampering fault in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor. The larger the first calibration value, the lower the probability of the position tampering fault. The first calibration value is greater than or equal to 0 to ensure the sensitivity of fault detection.

[0098] To further ensure the accuracy of fault detection, in an optional implementation manner, the second determining unit further includes:

[0099] a first processing module, configured to increment the number of errors by 1 and clear the first measurement cumulative value and the second measurement cumulative value to zero when the target cumulative deviation rate is greater than or equal to the first calibration value and less than a second calibration value, and the second calibration value is greater than the first calibration value;

[0100] a second processing module, configured to, when the target cumulative deviation rate is greater than or equal to a second calibration value, decrement the number of errors by 1 and clear the first measurement cumulative value and the second measurement cumulative value to zero;

[0101] The second determining module is configured to determine that a position tampering fault exists in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor when the number of errors is greater than a predetermined number.

[0102] Specifically, the larger the above-mentioned first calibration value is, the lower the probability of position tampering failure is. However, when the above-mentioned target cumulative deviation rate is greater than or equal to the above-mentioned first calibration value, there is still a risk of position tampering failure. The second calibration value is determined through experimental calibration. If the above-mentioned target cumulative deviation rate is greater than the second calibration value, the probability of position tampering failure is low. The number of errors is reduced by 1. When the above-mentioned target cumulative deviation rate is greater than or equal to the above-mentioned first calibration value and less than the second calibration value, the probability of position tampering failure is high. The number of errors is increased by 1. Finally, if the number of errors is greater than the predetermined number, it can be determined that the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor have position tampering failures, which reduces the randomness and improves the accuracy of judgment.

[0103] In order to simplify the detection workload, in an optional implementation, the first determination module includes:

[0104] The determination submodule is configured to determine, when the target cumulative deviation rate is less than 0, whether a position tampering fault exists in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

[0105] Specifically, when the above-mentioned target cumulative deviation rate is less than 0, it indicates that the above-mentioned first measurement cumulative value is greater than the above-mentioned second measurement cumulative value, that is, the measurement value of the downstream nitrogen oxide sensor is higher than the measurement value of the upstream nitrogen oxide sensor as a whole. It can be directly determined that the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor have position tampering faults without the need to compare with the calibration value.

[0106] In order to further ensure the accuracy of fault detection, in an optional embodiment, the enabling conditions include the upstream nitrogen oxide sensor is fault-free, the downstream nitrogen oxide sensor is fault-free, the urea injection device is fault-free, and the exhaust gas of the SCR system meets the NO x Emission standards, ambient temperature is within a predetermined temperature range, and ambient pressure is within a predetermined pressure range.

[0107] Specifically, the enabling condition judgment steps are as follows: 1) Upstream NO x Signal status: According to upstream NO x Whether the signal has a valid value is determined; 2) downstream NO x Signal status: According to downstream NO x 3) Urea injection status: Determine whether the urea is injected; 4) Ambient pressure status: whether the ambient pressure is valid; 5) Ambient temperature status: whether the ambient temperature is valid; 6) Whether the SCR system currently has a fault prohibition NO x Monitor and release; 7) NH3 storage level: Does the NH3 storage level meet the NO x Monitor the release requirements for the current hydrocarbon level: whether the current hydrocarbon level meets the NO x Monitoring release requirements, therefore, the above upstream nitrogen oxide sensor is fault-free, the above downstream nitrogen oxide sensor is fault-free, the urea injection device is fault-free, and the exhaust of the above SCR system meets NO x If the emission standards, the ambient temperature being within a predetermined temperature range, and the ambient pressure being within a predetermined pressure range are all met, it can be determined that the SCR system, the upstream nitrogen oxide sensor, and the downstream nitrogen oxide sensor are all operating without fault.

[0108] The aforementioned device for detecting a position tampering fault in a nitrogen oxide sensor includes a processor and a memory. The aforementioned calculation unit, first determination unit, and second determination unit are stored as program units in the memory. The processor executes the program units stored in the memory to implement the corresponding functions. The aforementioned modules may all be located in the same processor; alternatively, the aforementioned modules may be located in different processors in any combination.

[0109] The processor includes a core that retrieves corresponding program units from memory. One or more cores can be configured to adjust core parameters to address the inaccurate position tampering fault detection issue with the upstream and downstream nitrogen oxide sensors of the SCR in the prior art.

[0110] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0111] An embodiment of the present invention provides a computer-readable storage medium, which includes a stored program. When the program is run, the device where the computer-readable storage medium is located is controlled to execute the method for detecting the position tampering fault of the nitrogen oxide sensor.

[0112] Specifically, the method for detecting the position tampering fault of the nitrogen oxide sensor includes:

[0113] Step S201, when an enabling condition and a stable operating condition are met, calculating in real time the cumulative deviation rates of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor, the cumulative deviation rate being the difference between 1 and a cumulative ratio, the cumulative ratio being the ratio of a first measurement cumulative value to a second measurement cumulative value, the first measurement cumulative value being the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor, and the second measurement cumulative value being the cumulative value of the measurement values ​​of the upstream nitrogen oxide sensor, the enabling condition being that the SCR system, the upstream nitrogen oxide sensor, and the downstream nitrogen oxide sensor are all operating without fault, and the stable operating condition being that the temperature and temperature change rate of the SCR system are respectively within corresponding predetermined ranges, the flow rate of the exhaust gas is within a corresponding predetermined range, and the rate of change of the flow rate of the exhaust gas is within a corresponding predetermined range;

[0114] Specifically, when the SCR system operates without faults under stable operating conditions, it indicates that NO x The conversion efficiency is high, and the upstream and downstream NO x The concentration difference is obvious. The upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor measure once at a predetermined interval, for example, at an interval of 1s, the measurement values ​​of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are accumulated, and the cumulative deviation rate = 1-∑measurement value of the downstream nitrogen oxide sensor / ∑measurement value of the upstream nitrogen oxide sensor is calculated in real time.

[0115] Step S202: When the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, determining the current cumulative deviation rate as a target cumulative deviation rate, wherein the cumulative time is the duration of time during which the enabling condition and the stable operating condition are satisfied, and the cumulative flow rate is the cumulative value of the instantaneous flow rate of the exhaust gas within the cumulative time;

[0116] Specifically, if the cumulative time is lower than the predetermined time, or the cumulative flow of exhaust gas is lower than the predetermined cumulative value, the measurement values ​​of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are too few and not representative, and the chance of accidental detection is too high. When the cumulative time reaches the predetermined time and / or the cumulative flow of exhaust gas reaches the predetermined cumulative value, the accidental detection can be eliminated, and the current cumulative deviation rate can be used as the target cumulative deviation rate to judge the position tampering fault with higher accuracy.

[0117] Step S203, determining whether there is a position tampering fault in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor at least based on the size of the target cumulative deviation rate, where the position tampering fault is caused by the interchange of positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

[0118] Specifically, since the SCR system operates without failure under stable operating conditions, NO x The conversion efficiency is high, and the upstream and downstream NO x The concentration difference is obvious, however, the smaller the above-mentioned cumulative deviation rate is, the closer the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor is, and the higher the probability that the positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are interchanged. Therefore, it is possible to determine whether there is a position tampering fault in the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor based on the size of the above-mentioned target cumulative deviation rate.

[0119] Optionally, before the above-mentioned step S202, the above-mentioned method also includes: step S301, when the above-mentioned enabling condition is not met, clearing the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value to zero; step S302, when the above-mentioned enabling condition is met and the above-mentioned stable operating condition is not met, freezing the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value until the above-mentioned stable operating condition is met.

[0120] Optionally, before the above-mentioned step S202, the above-mentioned method also includes: step S401, when the above-mentioned cumulative time is less than the above-mentioned predetermined time and the above-mentioned enabling condition is not met, the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value are cleared to zero; step S402, when the above-mentioned cumulative time is less than the above-mentioned predetermined time and the above-mentioned stable operating condition is not met, the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value are cleared to zero; step S403, when the above-mentioned cumulative time is greater than or equal to the above-mentioned predetermined time, the above-mentioned cumulative flow is less than the above-mentioned predetermined cumulative value and the above-mentioned enabling condition is not met, the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value are cleared to zero; step S404, when the above-mentioned cumulative time is greater than or equal to the above-mentioned predetermined time, the above-mentioned cumulative flow is less than the above-mentioned predetermined cumulative value and the above-mentioned stable operating condition is not met, the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value are frozen until the above-mentioned stable operating condition is met.

[0121] Optionally, the above-mentioned step S203 includes: step S2031, when the above-mentioned target cumulative deviation rate is less than a first calibration value, determining that the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor have a position tampering fault, and the above-mentioned first calibration value is greater than or equal to 0.

[0122] Optionally, the above-mentioned step S203 also includes: step S2032, when the above-mentioned target cumulative deviation rate is greater than or equal to the above-mentioned first calibration value and less than the second calibration value, the number of errors is increased by 1 and the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value are cleared, and the above-mentioned second calibration value is greater than the above-mentioned first calibration value; step S2033, when the above-mentioned target cumulative deviation rate is greater than or equal to the second calibration value, the number of errors is reduced by 1 and the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value are cleared; step S2033, when the above-mentioned number of errors is greater than the predetermined number, it is determined that the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor have a position tampering fault.

[0123] Optionally, the step S2031 includes: step S20311, when the target cumulative deviation rate is less than 0, determining that there is a position tampering fault in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

[0124] An embodiment of the present invention provides a processor, which is used to run a program, wherein the program executes the method for detecting the position tampering fault of the nitrogen oxide sensor when running.

[0125] Specifically, the method for detecting the position tampering fault of the nitrogen oxide sensor includes:

[0126] Step S201, when an enabling condition and a stable operating condition are met, calculating in real time the cumulative deviation rates of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor, the cumulative deviation rate being the difference between 1 and a cumulative ratio, the cumulative ratio being the ratio of a first measurement cumulative value to a second measurement cumulative value, the first measurement cumulative value being the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor, and the second measurement cumulative value being the cumulative value of the measurement values ​​of the upstream nitrogen oxide sensor, the enabling condition being that the SCR system, the upstream nitrogen oxide sensor, and the downstream nitrogen oxide sensor are all operating without fault, and the stable operating condition being that the temperature and temperature change rate of the SCR system are respectively within corresponding predetermined ranges, the flow rate of the exhaust gas is within a corresponding predetermined range, and the rate of change of the flow rate of the exhaust gas is within a corresponding predetermined range;

[0127] Specifically, when the SCR system operates without faults under stable operating conditions, it indicates that NO x The conversion efficiency is high, and the upstream and downstream NO x The concentration difference is obvious. The upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor measure once at a predetermined interval, for example, at an interval of 1s, the measurement values ​​of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are accumulated, and the cumulative deviation rate = 1-∑measurement value of the downstream nitrogen oxide sensor / ∑measurement value of the upstream nitrogen oxide sensor is calculated in real time.

[0128] Step S202: When the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, determining the current cumulative deviation rate as a target cumulative deviation rate, wherein the cumulative time is the duration of time during which the enabling condition and the stable operating condition are satisfied, and the cumulative flow rate is the cumulative value of the instantaneous flow rate of the exhaust gas within the cumulative time;

[0129] Specifically, if the cumulative time is lower than the predetermined time, or the cumulative flow of exhaust gas is lower than the predetermined cumulative value, the measurement values ​​of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are too few and not representative, and the chance of accidental detection is too high. When the cumulative time reaches the predetermined time and / or the cumulative flow of exhaust gas reaches the predetermined cumulative value, the accidental detection can be eliminated, and the current cumulative deviation rate can be used as the target cumulative deviation rate to judge the position tampering fault with higher accuracy.

[0130] Step S203, determining whether there is a position tampering fault in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor at least based on the size of the target cumulative deviation rate, where the position tampering fault is caused by the interchange of positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

[0131] Specifically, since the SCR system operates without failure under stable operating conditions, NO x The conversion efficiency is high, and the upstream and downstream NO x The concentration difference is obvious, however, the smaller the above-mentioned cumulative deviation rate is, the closer the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor is, and the higher the probability that the positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are interchanged. Therefore, it is possible to determine whether there is a position tampering fault in the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor based on the size of the above-mentioned target cumulative deviation rate.

[0132] Optionally, before the above-mentioned step S202, the above-mentioned method also includes: step S301, when the above-mentioned enabling condition is not met, clearing the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value to zero; step S302, when the above-mentioned enabling condition is met and the above-mentioned stable operating condition is not met, freezing the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value until the above-mentioned stable operating condition is met.

[0133] Optionally, before the above-mentioned step S202, the above-mentioned method also includes: step S401, when the above-mentioned cumulative time is less than the above-mentioned predetermined time and the above-mentioned enabling condition is not met, the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value are cleared to zero; step S402, when the above-mentioned cumulative time is less than the above-mentioned predetermined time and the above-mentioned stable operating condition is not met, the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value are cleared to zero; step S403, when the above-mentioned cumulative time is greater than or equal to the above-mentioned predetermined time, the above-mentioned cumulative flow is less than the above-mentioned predetermined cumulative value and the above-mentioned enabling condition is not met, the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value are cleared to zero; step S404, when the above-mentioned cumulative time is greater than or equal to the above-mentioned predetermined time, the above-mentioned cumulative flow is less than the above-mentioned predetermined cumulative value and the above-mentioned stable operating condition is not met, the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value are frozen until the above-mentioned stable operating condition is met.

[0134] Optionally, the above-mentioned step S203 includes: step S2031, when the above-mentioned target cumulative deviation rate is less than a first calibration value, determining that the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor have a position tampering fault, and the above-mentioned first calibration value is greater than or equal to 0.

[0135] Optionally, the above-mentioned step S203 also includes: step S2032, when the above-mentioned target cumulative deviation rate is greater than or equal to the above-mentioned first calibration value and less than the second calibration value, the number of errors is increased by 1 and the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value are cleared, and the above-mentioned second calibration value is greater than the above-mentioned first calibration value; step S2033, when the above-mentioned target cumulative deviation rate is greater than or equal to the second calibration value, the number of errors is reduced by 1 and the above-mentioned first measurement cumulative value and the above-mentioned second measurement cumulative value are cleared; step S2033, when the above-mentioned number of errors is greater than the predetermined number, it is determined that the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor have a position tampering fault.

[0136] Optionally, the step S2031 includes: step S20311, when the target cumulative deviation rate is less than 0, determining that there is a position tampering fault in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

[0137] An embodiment of the present invention provides a vehicle, comprising: an SCR system, an upstream nitrogen oxide sensor, a downstream nitrogen oxide sensor, one or more processors, a memory, and one or more programs, wherein the upstream nitrogen oxide sensor is arranged on an exhaust pipe connected to the inlet of the SCR system, and the downstream nitrogen oxide sensor is arranged on the exhaust pipe connected to the outlet of the SCR system. The one or more programs are stored in the memory and are configured to be executed by the one or more processors. The one or more programs include methods for executing any one of the above methods.

[0138] Specifically, the method for detecting the position tampering fault of the nitrogen oxide sensor includes:

[0139] Step S201, when an enabling condition and a stable operating condition are met, calculating in real time the cumulative deviation rates of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor, the cumulative deviation rate being the difference between 1 and a cumulative ratio, the cumulative ratio being the ratio of a first measurement cumulative value to a second measurement cumulative value, the first measurement cumulative value being the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor, and the second measurement cumulative value being the cumulative value of the measurement values ​​of the upstream nitrogen oxide sensor, the enabling condition being that the SCR system, the upstream nitrogen oxide sensor, and the downstream nitrogen oxide sensor are all operating without fault, and the stable operating condition being that the temperature and temperature change rate of the SCR system are respectively within corresponding predetermined ranges, the flow rate of the exhaust gas is within a corresponding predetermined range, and the rate of change of the flow rate of the exhaust gas is within a corresponding predetermined range;

[0140] Specifically, when the SCR system operates without faults under stable operating conditions, it indicates that NO x The conversion efficiency is high, and the upstream and downstream NO x The concentration difference is obvious. The upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor measure once at a predetermined interval, for example, at an interval of 1s, the measurement values ​​of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are accumulated, and the cumulative deviation rate = 1-∑measurement value of the downstream nitrogen oxide sensor / ∑measurement value of the upstream nitrogen oxide sensor is calculated in real time.

[0141] Step S202: When the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, determining the current cumulative deviation rate as a target cumulative deviation rate, wherein the cumulative time is the duration of time during which the enabling condition and the stable operating condition are satisfied, and the cumulative flow rate is the cumulative value of the instantaneous flow rate of the exhaust gas within the cumulative time;

[0142] Specifically, if the cumulative time is lower than the predetermined time, or the cumulative flow of exhaust gas is lower than the predetermined cumulative value, the measurement values ​​of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are too few and not representative, and the chance of accidental detection is too high. When the cumulative time reaches the predetermined time and / or the cumulative flow of exhaust gas reaches the predetermined cumulative value, the accidental detection can be eliminated, and the current cumulative deviation rate can be used as the target cumulative deviation rate to judge the position tampering fault with higher accuracy.

[0143] Step S203, determining whether there is a position tampering fault in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor at least based on the size of the target cumulative deviation rate, where the position tampering fault is caused by the interchange of positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

[0144] Specifically, since the SCR system operates without failure under stable operating conditions, NO x The conversion efficiency is high, and the upstream and downstream NO x The concentration difference is obvious, however, the smaller the above-mentioned cumulative deviation rate is, the closer the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor is, and the higher the probability that the positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are interchanged. Therefore, it is possible to determine whether there is a position tampering fault in the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor based on the size of the above-mentioned target cumulative deviation rate.

[0145] The present application also provides a computer program product, which, when executed on a data processing device, is adapted to execute a program for initializing at least the following method steps:

[0146] Step S201, when an enabling condition and a stable operating condition are met, calculating in real time the cumulative deviation rates of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor, the cumulative deviation rate being the difference between 1 and a cumulative ratio, the cumulative ratio being the ratio of a first measurement cumulative value to a second measurement cumulative value, the first measurement cumulative value being the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor, and the second measurement cumulative value being the cumulative value of the measurement values ​​of the upstream nitrogen oxide sensor, the enabling condition being that the SCR system, the upstream nitrogen oxide sensor, and the downstream nitrogen oxide sensor are all operating without fault, and the stable operating condition being that the temperature and temperature change rate of the SCR system are respectively within corresponding predetermined ranges, the flow rate of the exhaust gas is within a corresponding predetermined range, and the rate of change of the flow rate of the exhaust gas is within a corresponding predetermined range;

[0147] Specifically, when the SCR system operates without faults under stable operating conditions, it indicates that NO x The conversion efficiency is high, and the upstream and downstream NO xThe concentration difference is obvious. The upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor measure once at a predetermined interval, for example, at an interval of 1s, the measurement values ​​of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are accumulated, and the cumulative deviation rate = 1-∑measurement value of the downstream nitrogen oxide sensor / ∑measurement value of the upstream nitrogen oxide sensor is calculated in real time.

[0148] Step S202: When the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, determining the current cumulative deviation rate as a target cumulative deviation rate, wherein the cumulative time is the duration of time during which the enabling condition and the stable operating condition are satisfied, and the cumulative flow rate is the cumulative value of the instantaneous flow rate of the exhaust gas within the cumulative time;

[0149] Specifically, if the cumulative time is lower than the predetermined time, or the cumulative flow of exhaust gas is lower than the predetermined cumulative value, the measurement values ​​of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are too few and not representative, and the chance of accidental detection is too high. When the cumulative time reaches the predetermined time and / or the cumulative flow of exhaust gas reaches the predetermined cumulative value, the accidental detection can be eliminated, and the current cumulative deviation rate can be used as the target cumulative deviation rate to judge the position tampering fault with higher accuracy.

[0150] Step S203, determining whether there is a position tampering fault in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor at least based on the size of the target cumulative deviation rate, where the position tampering fault is caused by the interchange of positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

[0151] Specifically, since the SCR system operates without failure under stable operating conditions, NO x The conversion efficiency is high, and the upstream and downstream NO x The concentration difference is obvious, however, the smaller the above-mentioned cumulative deviation rate is, the closer the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor is, and the higher the probability that the positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor are interchanged. Therefore, it is possible to determine whether there is a position tampering fault in the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor based on the size of the above-mentioned target cumulative deviation rate.

[0152] Obviously, those skilled in the art will appreciate that the various modules or steps of the present invention described above can be implemented using a general-purpose computing device, can be centralized on a single computing device, or can be distributed across a network of multiple computing devices. They can be implemented using program code executable by the computing device, and thus, can be stored in a storage device and executed by the computing device. In some cases, the steps shown or described herein can be performed in a different order than that shown, or can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0153] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0154] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0155] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0156] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0157] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0158] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0159] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0160] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0161] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0162] 1) In the method for detecting the position tampering fault of the nitrogen oxide sensor of the present application, first, under the condition of satisfying the enabling condition and the stable operating condition, the cumulative deviation rate of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor is calculated in real time, the cumulative deviation rate is the difference between 1 and the cumulative ratio, the cumulative ratio is the ratio of the first measurement cumulative value and the second measurement cumulative value, the first measurement cumulative value is the cumulative value of the measurement value of the downstream nitrogen oxide sensor, the second measurement cumulative value is the cumulative value of the measurement value of the upstream nitrogen oxide sensor, the enabling condition is that the SCR system operates without fault, the stable operating condition is that the temperature and temperature change rate of the SCR system are respectively within the corresponding predetermined ranges, and the flow rate of the exhaust gas is within the corresponding predetermined ranges. Within the corresponding predetermined range and the rate of change of the flow of the above-mentioned exhaust gas is within the corresponding predetermined range; then, when the cumulative time reaches the predetermined time and / or the cumulative flow of the above-mentioned exhaust gas reaches the predetermined cumulative value, determine the current above-mentioned cumulative deviation rate as the target cumulative deviation rate, the above-mentioned cumulative time is the duration of satisfying the above-mentioned enabling conditions and the above-mentioned stable operating conditions, and the above-mentioned cumulative flow is the cumulative value of the instantaneous flow of the above-mentioned exhaust gas within the above-mentioned cumulative time; finally, determine whether there is a position tampering fault in the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor at least based on the size of the above-mentioned target cumulative deviation rate, and the above-mentioned position tampering fault is a fault caused by the interchange of the positions of the above-mentioned upstream nitrogen oxide sensor and the above-mentioned downstream nitrogen oxide sensor. In this method, when the SCR system is operating without fault under stable conditions, the upstream and downstream NO x The concentration difference is obvious, and the cumulative deviation rate of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor is calculated in real time. When the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, it is determined that the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor is more representative, and the current cumulative deviation rate is used as the target cumulative deviation rate. Since the cumulative deviation rate is the difference between 1 and the cumulative ratio, where the cumulative ratio is the ratio of the cumulative value of the measurement value of the downstream nitrogen oxide sensor to the cumulative value of the measurement value of the upstream nitrogen oxide sensor, the smaller the cumulative deviation rate, the closer the cumulative value of the measurement value of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor, and the higher the probability that the position of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor is interchanged, it can be determined whether the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault based on the size of the cumulative deviation rate. This method only collects the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor when the SCR system is running without fault under stable conditions for cumulative deviation rate, to ensure that the upstream and downstream NO x The concentration difference is obvious, which greatly reduces the influence of working conditions on the measurement values ​​of upstream and downstream nitrogen oxide sensors, accurately detects position tampering faults, and solves the problem of inaccurate detection of position tampering faults of upstream and downstream nitrogen oxide sensors of SCR in the prior art.

[0163] 2) In the detection device for the position tampering fault of the nitrogen oxide sensor of the present application, the calculation unit calculates the cumulative deviation rate of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor in real time when the enabling condition and the stable operating condition are met. The cumulative deviation rate is the difference between 1 and the cumulative ratio. The cumulative ratio is the ratio of the first measurement cumulative value to the second measurement cumulative value. The first measurement cumulative value is the cumulative value of the measurement value of the downstream nitrogen oxide sensor, and the second measurement cumulative value is the cumulative value of the measurement value of the upstream nitrogen oxide sensor. The enabling condition is that the SCR system operates without fault, and the stable operating condition is that the temperature and temperature change rate of the SCR system are respectively within the corresponding predetermined ranges, and the flow rate of the exhaust gas is within the corresponding predetermined range. The first determination unit determines that the current cumulative deviation rate is the target cumulative deviation rate when the cumulative time reaches the predetermined time and / or the cumulative flow of the exhaust gas reaches the predetermined cumulative value. The cumulative time is the duration of time for satisfying the enabling conditions and the stable operating conditions. The cumulative flow is the cumulative value of the instantaneous flow of the exhaust gas within the cumulative time. The second determination unit determines whether there is a position tampering fault in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor at least based on the size of the target cumulative deviation rate. The position tampering fault is a fault caused by the interchange of the positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor. In this device, when the SCR system is operating without fault under stable conditions, the upstream and downstream NO x The concentration difference is obvious, and the cumulative deviation rate of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor is calculated in real time. When the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, it is determined that the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor is more representative, and the current cumulative deviation rate is used as the target cumulative deviation rate. Since the cumulative deviation rate is the difference between 1 and the cumulative ratio, where the cumulative ratio is the ratio of the cumulative value of the measurement value of the downstream nitrogen oxide sensor to the cumulative value of the measurement value of the upstream nitrogen oxide sensor, the smaller the cumulative deviation rate, the closer the cumulative value of the measurement value of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor, and the higher the probability that the position of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor is interchanged, it can be determined whether the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault based on the size of the cumulative deviation rate. This method only collects the measurement values ​​of the downstream nitrogen oxide sensor and the upstream nitrogen oxide sensor when the SCR system is running without fault under stable conditions for cumulative deviation rate, to ensure that the upstream and downstream NO x The concentration difference is obvious, which greatly reduces the influence of working conditions on the measurement values ​​of upstream and downstream nitrogen oxide sensors, accurately detects position tampering faults, and solves the problem of inaccurate detection of position tampering faults of upstream and downstream nitrogen oxide sensors of SCR in the prior art.

[0164] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for detecting position tampering fault of a nitrogen oxide sensor, characterized in that: An upstream nitrogen oxide sensor is disposed on an exhaust pipe connected to an inlet of an SCR system, and a downstream nitrogen oxide sensor is disposed on an exhaust pipe connected to an outlet of the SCR system. The method includes: Under the condition that an enabling condition and a stable operating condition are met, calculating in real time a cumulative deviation rate of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor, the cumulative deviation rate being the difference between 1 and a cumulative ratio, the cumulative ratio being the ratio of a first measurement cumulative value to a second measurement cumulative value, the first measurement cumulative value being the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor, and the second measurement cumulative value being the cumulative value of the measurement values ​​of the upstream nitrogen oxide sensor, the enabling condition being that the SCR system, the upstream nitrogen oxide sensor, and the downstream nitrogen oxide sensor are all operating without fault, and the stable operating condition being that the temperature and the temperature change rate of the SCR system are respectively within corresponding predetermined ranges, the flow rate of the exhaust gas is within the corresponding predetermined range, and the change rate of the flow rate of the exhaust gas is within the corresponding predetermined range; When the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, determining the current cumulative deviation rate as a target cumulative deviation rate, wherein the cumulative time is the duration during which the enabling condition and the stable operating condition are satisfied, and the cumulative flow rate is the cumulative value of the instantaneous flow rate of the exhaust gas within the cumulative time; Whether the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault is determined at least according to the size of the target cumulative deviation rate, and the position tampering fault is a fault caused by the position exchange of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

2. The method according to claim 1, characterized in that When the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, before determining the current cumulative deviation rate as a target cumulative deviation rate, the method further includes: If the enabling condition is not met, clearing the first measurement cumulative value and the second measurement cumulative value to zero; When the enabling condition is met and the stable operating condition is not met, the first measurement cumulative value and the second measurement cumulative value are frozen until the stable operating condition is met.

3. The method according to claim 1, characterized in that When the cumulative time reaches a predetermined time and / or the cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, before determining the current cumulative deviation rate as a target cumulative deviation rate, the method further includes: When the accumulated time is less than the predetermined time and the enabling condition is not satisfied, clearing the first measurement accumulated value and the second measurement accumulated value to zero; When the accumulated time is less than the predetermined time and the stable working condition is not satisfied, clearing the first measurement accumulated value and the second measurement accumulated value to zero; When the accumulated time is greater than or equal to the predetermined time, the accumulated flow rate is less than the predetermined accumulated value, and the enabling condition is not satisfied, clearing the first measurement accumulated value and the second measurement accumulated value; When the accumulated time is greater than or equal to the predetermined time, the accumulated flow is less than the predetermined accumulated value, and the stable operating condition is not met, the first measurement accumulated value and the second measurement accumulated value are frozen until the stable operating condition is met.

4. The method according to claim 1, wherein Determining whether the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have position tampering faults based on at least the magnitude of the target cumulative deviation rate includes: When the target cumulative deviation rate is less than a first calibration value, it is determined that a position tampering fault exists in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor, and the first calibration value is greater than or equal to 0.

5. The method according to claim 4, characterized in that Determining whether the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have position tampering faults based on at least the magnitude of the target cumulative deviation rate further includes: In a case where the target cumulative deviation rate is greater than or equal to the first calibration value and less than a second calibration value, adding 1 to the number of errors and clearing the first measurement cumulative value and the second measurement cumulative value, the second calibration value being greater than the first calibration value; When the target cumulative deviation rate is greater than or equal to a second calibration value, subtract 1 from the number of errors and clear the first measurement cumulative value and the second measurement cumulative value; When the number of errors is greater than a predetermined number, it is determined that position tampering faults exist in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

6. The method according to claim 4, characterized in that When the target cumulative deviation rate is less than a first calibration value, determining that a position tampering fault exists in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor includes: When the target cumulative deviation rate is less than 0, it is determined that position tampering faults exist in the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

7. The method according to any one of claims 1 to 6, characterized in that The enabling conditions include that the upstream nitrogen oxide sensor is not faulty, the downstream nitrogen oxide sensor is not faulty, the urea injection device is not faulty, and the exhaust gas of the SCR system meets the NO x Emission standards, ambient temperature is within a predetermined temperature range, and ambient pressure is within a predetermined pressure range.

8. A device for detecting position tampering failure of a nitrogen oxide sensor, characterized in that: The upstream nitrogen oxide sensor is arranged on the exhaust pipe connected to the inlet of the SCR system, and the downstream nitrogen oxide sensor is arranged on the exhaust pipe connected to the outlet of the SCR system. The device comprises: a calculation unit, configured to calculate, in real time, a cumulative deviation rate of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor when an enabling condition and a stable operating condition are satisfied, the cumulative deviation rate being the difference between 1 and a cumulative ratio, the cumulative ratio being the ratio of a first measurement cumulative value to a second measurement cumulative value, the first measurement cumulative value being the cumulative value of the measurement values ​​of the downstream nitrogen oxide sensor, and the second measurement cumulative value being the cumulative value of the measurement values ​​of the upstream nitrogen oxide sensor, the enabling condition being that the SCR system, the upstream nitrogen oxide sensor, and the downstream nitrogen oxide sensor are all operating without fault, and the stable operating condition being that the temperature and temperature change rate of the SCR system are respectively within corresponding predetermined ranges, the flow rate of the exhaust gas is within the corresponding predetermined range, and the rate of change of the flow rate of the exhaust gas is within the corresponding predetermined range; a first determining unit, configured to determine the current cumulative deviation rate as a target cumulative deviation rate when a cumulative time reaches a predetermined time and / or a cumulative flow rate of the exhaust gas reaches a predetermined cumulative value, wherein the cumulative time is a duration during which the enabling condition and the stable operating condition are satisfied, and the cumulative flow rate is a cumulative value of the instantaneous flow rate of the exhaust gas within the cumulative time; The second determination unit is used to determine whether the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor have a position tampering fault based on at least the size of the target cumulative deviation rate, where the position tampering fault is a fault caused by the interchange of positions of the upstream nitrogen oxide sensor and the downstream nitrogen oxide sensor.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute the method according to any one of claims 1 to 7.

10. A vehicle, characterized in that: include: An SCR system, an upstream nitrogen oxide sensor, a downstream nitrogen oxide sensor, one or more processors, a memory, and one or more programs, wherein the upstream nitrogen oxide sensor is arranged on an exhaust pipe connected to an inlet of the SCR system, and the downstream nitrogen oxide sensor is arranged on an exhaust pipe connected to an outlet of the SCR system, the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include instructions for executing the method according to any one of claims 1 to 7.

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