Fault simulation method, device and equipment for front oxygen sensor and storage medium

Abstract

The invention discloses a fault simulation method, device and equipment for a front oxygen sensor and a storage medium, and belongs to the field of engine control. According to the method and the device, fault simulation is carried out on the front oxygen sensor from a software level, fault simulation equipment in a hardware form does not need to be externally connected, the cost is reduced, and the problem that the fault simulation equipment is difficult to match with the front oxygen sensor due to numerous types of the fault simulation equipment is solved. Besides, in the fault simulation process, hardware or underlying codes do not need to be modified, only relevant personnel need to modify the values of the parameters capable of being calibrated, operation is simpler and more convenient, and the efficiency and flexibility of fault simulation are greatly improved. Besides, accurate control over fault simulation signals is achieved based on pump current signals, parameters capable of being calibrated and the like, related personnel can be helped to accurately understand the influence of the front oxygen sensor faults on the engine, and a powerful basis is provided for dealing with the front oxygen sensor faults in actual scenes.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engine control, and in particular to a method and device for simulating a fault of a front oxygen sensor, an equipment and a storage medium. BACKGROUND

[0002] The front oxygen sensor is a key component of the engine control system, and is usually installed on the exhaust pipe close to the engine. It is used to monitor the oxygen content in the exhaust gas in real time, and feed back a voltage signal to the ECU (Engine Control Unit, engine control unit), and the ECU adjusts the fuel injection amount of the fuel injector accordingly to ensure that the actual air-fuel ratio is as close to the ideal air-fuel ratio as possible.

[0003] Wherein, the fault of the front oxygen sensor will cause the ECU to be unable to accurately control the air-fuel ratio, and thus may cause the engine to have problems such as unstable idle speed, increased fuel consumption, decreased power, or excessive emissions. In order to improve the fault diagnosis ability of maintenance personnel and other purposes, the front oxygen sensor can be simulated in advance to help maintenance personnel understand the influence of the front oxygen sensor fault on the engine and the diagnosis logic.

[0004] During fault simulation, the cost, whether the operation is convenient, and whether the fault can be accurately reproduced directly determine the value of the fault simulation. Therefore, how to simulate the fault of the front oxygen sensor has become a problem to be solved by those skilled in the art. SUMMARY

[0005] The embodiments of the present application provide a method and device for simulating a fault of a front oxygen sensor, an equipment and a storage medium. The technical solution is as follows:

[0006] On the one hand, a method for simulating a fault of a front oxygen sensor is provided, and the method comprises:

[0007] Obtaining a pump current signal of the front oxygen sensor; wherein the pump current signal is used to reflect the current flowing through the pump cell of the front oxygen sensor;

[0008] Converting the pump current signal into an air-fuel ratio of the mixed gas to obtain a first air-fuel ratio;

[0009]

[0009] Based on a cross-sensitivity correction coefficient and an air-fuel ratio offset correction coefficient, correcting the first air-fuel ratio to obtain a second air-fuel ratio; wherein the cross-sensitivity correction coefficient is used to eliminate the measurement deviation related to the front oxygen sensor, and the air-fuel ratio offset correction coefficient is used to eliminate the system deviation related to the engine;

[0010] When simulating the double-edge delay fault of the front oxygen sensor, a first modification value of a calibratable parameter is obtained, and a first fault simulation signal is output according to a first delay time indicated by the first modification value;

[0011] The first fault simulation signal is the second air-fuel ratio after being processed by the double-lag processing; the double-lag processing refers to outputting the second air-fuel ratio after lagging the first delay time when the value of the second air-fuel ratio increases or decreases.

[0012] In some embodiments, the method further comprises:

[0013] Obtaining the reciprocal of the second air-fuel ratio to obtain a first basic parameter for fuel injection control;

[0014] The double-lag processing refers to outputting the first basic parameter after lagging the first delay time when the value of the first basic parameter increases or decreases.

[0015] In some embodiments, the method further comprises:

[0016] When simulating a single-lag delay fault of the front oxygen sensor, if a preset triggering condition is met, adjusting the second air-fuel ratio based on an adjustment factor to make it fit a target air-fuel ratio to obtain a third air-fuel ratio;

[0017] Obtaining a second modification value of the calibratable parameter, and outputting a second fault simulation signal according to a second delay time indicated by the second modification value;

[0018] The second fault simulation signal is the third air-fuel ratio after being processed by the single-lag processing; the single-lag processing refers to outputting the third air-fuel ratio after lagging the second delay time when the value of the third air-fuel ratio increases or decreases.

[0019] In some embodiments, the method further comprises:

[0020] When simulating a transient response fault of the front oxygen sensor, obtaining a working condition parameter of the engine, and determining a calibratable correction coefficient according to the working condition parameter; the correction coefficient is used to adjust the change rate of the second air-fuel ratio;

[0021] Performing a multiplication operation on the second air-fuel ratio and the correction coefficient to obtain a transient response fault curve of the air-fuel ratio.

[0022] In some embodiments, the method further comprises:

[0023] Determining the correction coefficient corresponding to the working condition parameter by querying a calibratable mapping table; the mapping table is used to store the corresponding relationship between the working condition parameter of the engine and the correction coefficient.

[0024] In some embodiments, the method further comprises:

[0025] If the preset triggering condition is met, adjusting the fourth air-fuel ratio based on an adjustment factor to fit the target air-fuel ratio, to obtain a fifth air-fuel ratio;

[0026] The fourth air-fuel ratio is the product of the second air-fuel ratio and the correction factor.

[0027] In some embodiments, the adjustment factor is determined by:

[0028] obtaining an absolute value of the difference between the second air-fuel ratio and the target air-fuel ratio;

[0029] performing a PID (Proportional-Integral-Derivative) adjustment operation based on the absolute value to obtain the adjustment factor.

[0030] In another aspect, a fault simulation device for a front oxygen sensor is provided, the device comprising:

[0031] a first obtaining module configured to obtain a pump current signal of the front oxygen sensor, wherein the pump current signal is used to reflect the current flowing through a pump cell of the front oxygen sensor;

[0032] a second obtaining module configured to convert the pump current signal into an air-fuel ratio of a mixture to obtain a first air-fuel ratio;

[0033] a correction module configured to correct the first air-fuel ratio based on a cross-sensitivity correction factor and an air-fuel ratio offset correction factor to obtain a second air-fuel ratio, wherein the cross-sensitivity correction factor is used to eliminate measurement deviation related to the front oxygen sensor, and the air-fuel ratio offset correction factor is used to eliminate system deviation related to an engine;

[0034] a first calibration module configured to obtain a first modification value of a calibratable parameter when simulating a double-lag fault of the front oxygen sensor;

[0035] a fault simulation module configured to output a first fault simulation signal according to a first lag time indicated by the first modification value when simulating the double-lag fault;

[0036] The first fault simulation signal is the second air-fuel ratio after double-lag processing, and the double-lag processing refers to lagging the second air-fuel ratio by the first lag time when the value of the second air-fuel ratio increases or decreases.

[0037] In some embodiments, the device further comprises:

[0038] The third obtaining module is configured to obtain an inverse of the second air-fuel ratio, to obtain a first base parameter for fuel injection control;

[0039] The double-side delay processing refers to outputting the first base parameter after a delay of the first delay time when the value of the first base parameter increases or decreases.

[0040] In some other embodiments, the device further comprises:

[0041] The adjusting module is configured to, when simulating a single-side delay fault of the front oxygen sensor, adjust the second air-fuel ratio based on an adjustment factor to fit a target air-fuel ratio, to obtain a third air-fuel ratio, if a preset triggering condition is met;

[0042] The first calibration module is further configured to obtain a second modified value of the calibratable parameter when simulating the single-side delay fault.

[0043] The fault simulation module is further configured to output a second fault simulation signal according to a second delay time indicated by the second modified value when simulating the single-side delay fault.

[0044] The second fault simulation signal is the third air-fuel ratio after single-side delay processing, and the single-side delay processing refers to outputting the third air-fuel ratio after a delay of the second delay time when the value of the third air-fuel ratio increases or decreases.

[0045] In some other embodiments, the device further comprises:

[0046] The second calibration module is configured to, when simulating a transient response fault of the front oxygen sensor, obtain a working condition parameter of the engine, and determine a calibratable correction coefficient according to the working condition parameter; the correction coefficient is used to adjust a change rate of the second air-fuel ratio.

[0047] The fault simulation module is further configured to perform a multiplication operation on the second air-fuel ratio and the correction coefficient, to obtain a transient response fault curve of the air-fuel ratio.

[0048] In some other embodiments, the second calibration module is configured to:

[0049] The second calibration module is configured to:

[0050] In some other embodiments, the adjusting module is further configured to:

[0051] When simulating the transient response fault, if a preset triggering condition is met, a fourth air-fuel ratio is adjusted based on an adjustment factor to fit a target air-fuel ratio, and a fifth air-fuel ratio is obtained.

[0052] The fourth air-fuel ratio is a product of the second air-fuel ratio and the correction factor.

[0053] In some embodiments, the adjustment factor is determined by:

[0054] An absolute value of a difference between the second air-fuel ratio and the target air-fuel ratio is obtained.

[0055] A PID adjustment operation is performed based on the absolute value to obtain the adjustment factor.

[0056] In another aspect, a computer device is provided, which includes a processor and a memory, and the memory stores at least one program code, which is loaded and executed by the processor to implement the above-mentioned front oxygen sensor fault simulation method.

[0057] In another aspect, a computer readable storage medium is provided, which stores at least one program code, which is loaded and executed by a processor to implement the above-mentioned front oxygen sensor fault simulation method.

[0058] In another aspect, a computer program product or computer program is provided, which includes computer program code stored in a computer readable storage medium, and a processor of a computer device reads the computer program code from the computer readable storage medium, and the processor executes the computer program code to enable the computer device to perform the above-mentioned front oxygen sensor fault simulation method.

[0059] The fault simulation scheme provided by the embodiments of the present application realizes fault simulation of the front oxygen sensor from the software level, without the need for an external hardware form of fault simulation device, thereby not only reducing the cost, but also avoiding the problem of difficulty in matching the fault simulation device with the front oxygen sensor due to the large number of types of fault simulation devices. In addition, in the fault simulation process, the present application only needs to modify the value of the calibratable parameter, without modifying the hardware or the underlying code, and the operation is more simple and convenient, thereby greatly improving the efficiency and flexibility of fault simulation. In addition, the present application also realizes accurate control of the fault simulation signal based on the pump current signal and the calibratable parameter, which can help relevant personnel to accurately understand the influence of the front oxygen sensor fault on the engine, thereby providing a powerful help for coping with the front oxygen sensor fault in the actual scene, such as effectively preventing the problem of emission exceeding the standard, thereby achieving the purpose of protecting the environment. BRIEF DESCRIPTION OF DRAWINGS

[0060] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments description. Obviously, the drawings in the following description only some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0061] Figure 1 is a flow chart of a fault simulation method of a front oxygen sensor provided by the embodiments of the present application;

[0062] Figure 2 is a schematic diagram of a fault simulation flow of a front oxygen sensor provided by the embodiments of the present application;

[0063] Figure 3 is a structural schematic diagram of a fault simulation device of a front oxygen sensor provided by the embodiments of the present application;

[0064] Figure 4 is a structural schematic diagram of a computer device provided by the embodiments of the present application. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical solutions and advantages of the present application more clear, the following will further describe the embodiments of the present application in combination with the drawings.

[0066] The terms "first", "second" and the like in the present application are used to distinguish the same items or similar items with basically the same function, and it should be understood that there is no logical or time sequence relationship between "first", "second", "nth", and the number and execution order are not limited. It should also be understood that although the following description uses the terms first, second, etc. to describe various elements, these elements should not be limited by the terms.

[0067] These terms are only used to distinguish one element from another. For example, without departing from the scope of various examples, the first element can be called the second element, and similarly, the second element can also be called the first element. The first element and the second element can both be elements, and in some cases, can be separate and different elements.

[0068] Among them, at least one refers to one or more than one, for example, at least one element can be one element, two elements, three elements, etc. Any integer greater than or equal to one element. And multiple refers to two or more than two, for example, multiple elements can be two elements, three elements, etc. Any integer greater than or equal to two elements.

[0069] The "and / or" mentioned in the present text means that there can be three relationships, for example, A and / or B can represent: A exists alone, A and B exist together, and B exists alone. The character " / " generally represents an "or" relationship between the objects before and after it.

[0070] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data for analysis, stored data, displayed data, etc.) and signals involved in the present application are all authorized by the user or fully authorized by all parties, and the collection, use and processing of related data need to comply with relevant laws, regulations and standards in the relevant region.

[0071] The fault simulation scheme provided by the embodiment of the present application realizes that relevant personnel can simulate the fault of the front oxygen sensor from the software level through the computer device. Among them, the present scheme includes the following aspects:

[0072] 1. The present scheme can simulate the double-side delay fault of the front oxygen sensor. When simulating the double-side delay fault, the present scheme is realized through a delay module with a dynamically configurable delay time. That is, a flexible adjustable parameter (i.e. calibration value) is designed for this delay module, and by modifying this parameter, the delay time of the signal can be directly changed without modifying the hardware or the underlying code.

[0073] 2. The present scheme can simulate the single-side delay fault of the front oxygen sensor. When simulating the single-side delay fault, when the rich flag or the lean flag is detected, the present scheme will obtain the absolute value of the difference between the actual air-fuel ratio and the expected air-fuel ratio, and based on this absolute value, the PID adjustment is carried out, thereby realizing the single-side delay of the actual air-fuel ratio and the rapid fitting of the expected air-fuel ratio.

[0074] 3. The present scheme can simulate the instantaneous response fault of the front oxygen sensor. When simulating the instantaneous response fault, the present scheme can change the change rate of the actual air-fuel ratio by adding a calibratable mapping table, which realizes that only the calibratable mapping table needs to be modified to simulate the instantaneous response fault.

[0075] The following embodiments will be used to introduce the fault simulation scheme of the front oxygen sensor provided by the embodiment of the present application in detail.

[0076] Figure 1 is a flowchart of a fault simulation method of a front oxygen sensor provided by the embodiment of the present application. The execution subject of the method is a computer device. Referring to Figure 1 , the method includes the following steps:

[0077] 101、The computer device obtains a pump current signal of the front oxygen sensor and converts the pump current signal into an air-fuel ratio of the mixture to obtain a first air-fuel ratio; wherein the pump current signal is used to reflect the current flowing through the pump cell of the front oxygen sensor.

[0078] As an example, the front oxygen sensor is a wide-range front oxygen sensor, which is not limited in the present application.

[0079] Taking the wide-range front oxygen sensor as an example, its core components include a pump cell, a reference cell, and a control circuit. Among them, the pump cell is a ceramic element that can adjust the migration of oxygen through the current, and the pump current refers to the current flowing through the pump cell. The direction and size of the pump current change linearly with the oxygen concentration in the exhaust gas, and the pump current of the wide-range oxygen sensor has a linear correspondence with the actual air-fuel ratio.

[0080] As another example, the present scheme converts the pump current signal into the air-fuel ratio of the mixture through a mapping table between the pump current and the actual air-fuel ratio to obtain the first air-fuel ratio. Among them, the first air-fuel ratio is also referred to as the actual air-fuel ratio in this article.

[0081] 102、The computer device corrects the first air-fuel ratio based on the cross-sensitivity correction coefficient and the air-fuel ratio offset correction coefficient to obtain a second air-fuel ratio.

[0082] The first point to be explained is that the cross-sensitivity correction coefficient is used to eliminate the measurement deviation related to the front oxygen sensor. Among them, the wide-range oxygen sensor may be affected by other components in the exhaust gas or changes in temperature, pressure, etc., resulting in deviation in the measured actual air-fuel ratio. This coefficient is used to compensate for these interference factors to ensure the accuracy of the actual air-fuel ratio measurement.

[0083] The second point to be explained is that the air-fuel ratio offset correction coefficient is used to eliminate the system deviation related to the engine. Among them, due to individual differences of the engine (such as manufacturing tolerance, wear), changes in fuel quality, etc., the actual air-fuel ratio may have a systematic deviation from the theoretical control target. This coefficient is used to fine-tune the body deviation so that the air-fuel ratio is closer to the ideal control range.

[0084] As an example, based on the cross-sensitivity correction coefficient and the air-fuel ratio offset correction coefficient, the first air-fuel ratio is corrected, which means that the cross-sensitivity correction coefficient, the air-fuel ratio offset correction coefficient, and the first air-fuel ratio are subjected to a multiplication operation to obtain the second air-fuel ratio after eliminating the interference. Among them, the second air-fuel ratio is also referred to as the basic actual air-fuel ratio in this article.

[0085] The following steps 103-105 respectively introduce how to simulate double-sided delay faults, single-sided delay faults, and instantaneous response faults.

[0086] 103、In simulating the double-edge delay fault of the front oxygen sensor, the computer device obtains a first modified value of the markable parameter, and outputs a first fault simulation signal according to a first delay time indicated by the first modified value; wherein the first fault simulation signal is a second air-fuel ratio after double-edge delay processing.

[0087] In the embodiments of the present application, the double-edge delay processing refers to that when the value of the second air-fuel ratio increases (rising edge) and decreases (falling edge), the second air-fuel ratio is output after a first delay time.

[0088] wherein, Figure 3 is a schematic diagram of a fault simulation process of a front oxygen sensor provided by the embodiments of the present application. As an example, Figure 3 λ1 in the above formula refers to an actual air-fuel ratio, Figure 3 λ2 in the above formula refers to an expected air-fuel ratio, also referred to as a target air-fuel ratio.

[0089] As shown in the above formula, Figure 3 when simulating the double-edge delay fault, the present scheme is implemented by a delay module with a dynamically configurable delay time. Wherein, the function of this delay module is to perform time lag processing on the original signal (such as the basic actual air-fuel ratio), and the delay time is determined by a markable parameter. When it is necessary to simulate the double-edge delay fault, it is not necessary to modify the hardware or the underlying code, and only the value of the markable parameter needs to be modified by the relevant personnel, so that the signal can be delayed at the rising edge and the falling edge. The specific delay time is determined by the modified value of the markable parameter. In other words, when simulating the double-edge delay fault, the delay time can be flexibly adjusted by modifying the value of the markable parameter, so as to achieve the purpose of double-edge delay of the basic actual air-fuel ratio. That is, after modifying the value of the markable parameter, the signal will immediately produce double-edge delay according to the modified value of the markable parameter, thereby realizing the fault simulation of the wide-range oxygen sensor response delay or signal transmission delay.

[0090] Exemplarily, taking the modified value of the markable parameter as 100 ms as an example, the value of the basic actual air-fuel ratio before 100 ms is always output. That is, whether the value of the basic actual air-fuel ratio increases or decreases, it will lag 100 ms before following the change, thereby realizing the double-edge delay.

[0091] As another example, since the ECU usually needs to take the ratio of fuel to air as the basis for controlling fuel injection, rather than taking the ratio of air to fuel as the basis, the reciprocal of the second air-fuel ratio can also be obtained to obtain a first basic parameter for fuel injection control. Wherein, the first basic parameter is also referred to as the reciprocal of the basic actual air-fuel ratio in the present text.

[0092] Correspondingly, Figure 3 λ1 in the above formula can also refer to the reciprocal of the basic actual air-fuel ratio, Figure 3The λ2in the formula can also refer to the expected air-fuel ratio reciprocal, which is not limited in the present application. In this case, the double-lag delay processing refers to outputting the first basic parameter after a first delay time when the value of the first basic parameter increases or decreases. Similarly, when simulating the single-lag delay fault and the transient response fault, the basic actual air-fuel ratio reciprocal and the expected air-fuel ratio reciprocal can also be used, which is not limited in the present application.

[0093] 104. When simulating the single-lag delay fault of the front oxygen sensor, if a preset triggering condition is met, the computer device adjusts the second air-fuel ratio based on the adjustment factor to fit the target air-fuel ratio, to obtain a third air-fuel ratio; the computer device obtains a second modification value of the calibratable parameter, and outputs a second fault simulation signal according to a second delay time indicated by the second modification value; wherein the second fault simulation signal is the third air-fuel ratio after single-lag delay processing.

[0094] In the embodiments of the present application, the single-lag delay processing refers to outputting the third air-fuel ratio after a second delay time when the value of the third air-fuel ratio increases or decreases.

[0095] Exemplarily, as shown in Figure 3 The preset triggering condition is detecting the rich air-fuel ratio flag or the lean air-fuel ratio flag, which is not limited in the present application.

[0096] When simulating the single-lag delay fault, the flag is used for judgment, and only the delay calibration value is applied in the target state, and the delay is 0 (real-time response) in the non-target state. If the current simulation is the lean side delay, the single-lag delay is performed when the lean air-fuel ratio flag is detected. If the current simulation is the rich side delay, the single-lag delay is performed when the rich air-fuel ratio flag is detected.

[0097] As shown in Figure 3 When simulating the single-lag delay fault, PID adjustment is also involved. The essence of the PID adjustment is to calculate a suitable control amount according to the size, accumulation and change trend of the deviation (the absolute value of the difference between the actual air-fuel ratio and the target air-fuel ratio), so as to quickly fit the actual air-fuel ratio to the target air-fuel ratio even if there is a delay fault.

[0098] As an example, the value of the adjustment factor p in the PID adjustment process is determined by the following way:

[0099] An absolute value of a difference between the second air-fuel ratio and the target air-fuel ratio is obtained; a PID adjustment operation is performed based on the absolute value to obtain an adjustment factor p. The PID adjustment includes three components, namely, proportional adjustment, integral adjustment, and differential adjustment. The proportional adjustment is used to directly output a control amount proportional to a current deviation to quickly respond to the deviation. The integral adjustment is used to output a control amount based on a cumulative value (a sum of historical deviations) of the deviation to eliminate a steady-state deviation (a small deviation that exists for a long time) of the system. The differential adjustment is used to output a control amount based on a change rate (a derivative of the deviation) of the deviation to suppress overshoot (prevent the actual air-fuel ratio from exceeding the target air-fuel ratio too much).

[0100] 105、In simulating the transient response fault of the front oxygen sensor, the computer device obtains the operating parameter of the engine, and determines a calibratable correction coefficient according to the operating parameter; wherein the correction coefficient is used to adjust the change rate of the second air-fuel ratio; the computer device performs a multiplication operation on the second air-fuel ratio and the correction coefficient to obtain the transient response fault curve of the air-fuel ratio.

[0101] As shown in Figure 3 , in simulating the transient response fault of the front oxygen sensor, the present scheme first obtains the operating parameter (such as the speed and the load) of the engine, and then determines a calibratable correction coefficient k1 according to the obtained operating parameter. Wherein k1 is used to adjust the change rate of the actual air-fuel ratio (such as making the signal change slower or faster). Based on the above-mentioned role of k1, k1 is also called a slope coefficient or a slope factor.

[0102] As an example, as shown in Figure 3 , the correction coefficient corresponding to the obtained operating parameter (such as the speed and the load) can be determined by querying the calibratable mapping table. Wherein the mapping table is used to store the corresponding relationship between the operating parameter of the engine and the correction coefficient.

[0103] In other words, as shown in Figure 3 , in simulating the transient response fault, the corresponding correction coefficient k1 can be obtained by querying the above-mentioned mapping table based on the reciprocal of the basic actual air-fuel ratio, and multiplying the basic actual air-fuel ratio by this correction coefficient, the transient response fault curve of the actual air-fuel ratio is obtained, and the transient response fault is simulated. That is, by multiplying the basic actual air-fuel ratio by this correction coefficient, the present scheme artificially creates abnormal change characteristics of the signal, thereby reproducing the fault scene.

[0104] It should be noted that the calibrable mapping table and calibrable correction coefficients refer to the fact that when simulating transient response faults, the correction coefficients will be calibrated as outliers; that is, the mapping table stores outlier correction coefficients at this time. The outlier correction coefficients are read from this mapping table based on the acquired operating parameters. Furthermore, the fault curves obtained by this solution can accurately reproduce transient response faults, such as signals failing to follow changes in operating conditions at the normal rate, exhibiting sudden lag or jumps. This is consistent with the characteristics of wide-range oxygen sensor faults in real-world scenarios (such as ceramic element aging or poor circuit contact), achieving precise control of the fault simulation signal.

[0105] As another example, such as Figure 3 As shown, after obtaining the correction coefficient k1, the instantaneous response fault simulated based on k1 can be combined with a bilateral delay fault, or the instantaneous response fault simulated based on k1 can be combined with a unilateral delay fault to reproduce more complex and realistic pre-oxygen sensor faults. Furthermore, after obtaining the correction coefficient k1, if a preset triggering condition is met, this scheme will adjust the fourth air-fuel ratio based on the adjustment factor p to fit the target air-fuel ratio, thus obtaining the fifth air-fuel ratio. The fourth air-fuel ratio is the product of the second air-fuel ratio and the correction coefficient k1. Additionally, regarding the generation of bilateral or unilateral delays for the fourth air-fuel ratio, please refer to steps 102 or 103 above, which will not be elaborated here.

[0106] In summary, the fault simulation solution provided in this application enables fault simulation of the front oxygen sensor at the software level, eliminating the need for external hardware-based fault simulation equipment. This not only reduces costs but also avoids the difficulties in matching fault simulation devices with the front oxygen sensor caused by the wide variety of such devices. Furthermore, during fault simulation, this solution requires no modification to hardware or underlying code; only the values ​​of calibrable parameters need to be adjusted by relevant personnel, making operation simpler and more convenient, significantly improving the efficiency and flexibility of fault simulation. In addition, this solution achieves precise control of the fault simulation signal based on pump current signals and calibrable parameters, helping relevant personnel accurately understand the impact of front oxygen sensor faults on the engine. This provides strong support for addressing front oxygen sensor faults in real-world scenarios, such as effectively preventing excessive emissions and contributing to environmental protection.

[0107] Figure 3 This is a schematic diagram of a fault simulation device for a pre-oxygen sensor provided in an embodiment of this application. See also... Figure 4 The device includes:

[0108] The first acquisition module 301 is configured to acquire the pump current signal of the pre-oxygen sensor; wherein the pump current signal is used to reflect the magnitude of the current flowing through the pump battery of the pre-oxygen sensor.

[0109] The second acquisition module 302 is configured to convert the pump current signal into an air-fuel ratio of the mixed gas, to obtain a first air-fuel ratio;

[0110] The correction module 303 is configured to correct the first air-fuel ratio based on a cross-sensitivity correction coefficient and an air-fuel ratio offset correction coefficient, to obtain a second air-fuel ratio; wherein the cross-sensitivity correction coefficient is used to eliminate a measurement deviation related to the front oxygen sensor, and the air-fuel ratio offset correction coefficient is used to eliminate a system deviation related to the engine;

[0111] The first calibration module 304 is configured to obtain a first modification value of a calibratable parameter when simulating a double-side delay fault of the front oxygen sensor;

[0112] The fault simulation module 305 is configured to output a first fault simulation signal according to a first delay time indicated by the first modification value when simulating the double-side delay fault.

[0113] The first fault simulation signal is the second air-fuel ratio after double-side delay processing, and the double-side delay processing means that the second air-fuel ratio is output after being delayed by the first delay time when the value of the second air-fuel ratio increases or decreases.

[0114] The fault simulation scheme provided by the embodiments of the present application realizes fault simulation of the front oxygen sensor from the software level, without the need for an external hardware form of fault simulation device, thereby not only reducing the cost, but also avoiding problems such as difficulty in matching the fault simulation device with the front oxygen sensor due to a large number of types of fault simulation devices. In addition, in the fault simulation process, the present application does not need to modify the hardware or the underlying code, but only needs the relevant personnel to modify the value of the calibratable parameter, which is more simple and convenient to operate, and greatly improves the efficiency and flexibility of fault simulation. In addition, the present application realizes accurate control of the fault simulation signal based on the pump current signal and the calibratable parameter, which can help relevant personnel to accurately understand the influence of the front oxygen sensor fault on the engine, thereby providing strong help for coping with the front oxygen sensor fault in the actual scene, such as effectively preventing the problem of excessive emissions, thereby achieving the purpose of protecting the environment.

[0115] In some embodiments, the apparatus further comprises:

[0116] The third acquisition module is configured to obtain an inverse of the second air-fuel ratio, to obtain a first basic parameter for fuel injection control;

[0117] The double-side delay processing means that the first basic parameter is output after being delayed by the first delay time when the value of the first basic parameter increases or decreases.

[0118] In other embodiments, the apparatus further comprises:

[0119] an adjusting module configured to, when simulating the single-lag delay fault of the front oxygen sensor, adjust the second air-fuel ratio based on an adjustment factor to fit a target air-fuel ratio, if a preset triggering condition is met, to obtain a third air-fuel ratio;

[0120] The first calibration module is further configured to, when simulating the single-lag delay fault, obtain a second modification value of the calibratable parameter.

[0121] The fault simulation module is further configured to, when simulating the single-lag delay fault, output a second fault simulation signal according to a second delay time indicated by the second modification value.

[0122] The second fault simulation signal is the third air-fuel ratio after single-lag delay processing, and the single-lag delay processing refers to outputting the third air-fuel ratio after lagging the second delay time when the value of the third air-fuel ratio increases or decreases.

[0123] In some other embodiments, the device further comprises:

[0124] a second calibration module configured to, when simulating a transient response fault of the front oxygen sensor, obtain a working condition parameter of the engine, and determine a calibratable correction coefficient according to the working condition parameter; wherein the correction coefficient is used to adjust a change rate of the second air-fuel ratio.

[0125] The fault simulation module is further configured to perform a multiplication operation on the second air-fuel ratio and the correction coefficient to obtain a transient response fault curve of the air-fuel ratio.

[0126] In some other embodiments, the second calibration module is configured to:

[0127] determine the correction coefficient corresponding to the working condition parameter by querying a calibratable mapping table; wherein the mapping table is used to store a corresponding relationship between the working condition parameter of the engine and the correction coefficient.

[0128] In some other embodiments, the adjusting module is further configured to:

[0129] when simulating the transient response fault, adjust a fourth air-fuel ratio based on an adjustment factor to fit a target air-fuel ratio, if a preset triggering condition is met, to obtain a fifth air-fuel ratio;

[0130] The fourth air-fuel ratio is the product of the second air-fuel ratio and the correction coefficient.

[0131] In some other embodiments, the determination process of the adjustment factor comprises:

[0132] acquire an absolute value of a difference between the second air-fuel ratio and the target air-fuel ratio;

[0133] perform a PID adjustment operation based on the absolute value to obtain the adjustment factor.

[0134] All the optional technical solutions described above can be combined to form optional embodiments of the present application, which will not be described again.

[0135] It should be noted that: the above-mentioned embodiment provides a fault simulation device for a front oxygen sensor. When simulating the fault of the front oxygen sensor, only the division of the above-mentioned functional modules is used as an example for illustration. In actual application, the above-mentioned functions can be completed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the fault simulation device for the front oxygen sensor and the fault simulation method for the front oxygen sensor provided in the above-mentioned embodiment belong to the same concept, and the specific implementation process is described in the method embodiment, which will not be described again here.

[0136] ​ is a structural schematic diagram of a computer device provided by an embodiment of the present application.

[0137] Among them, the computer device 400 can have great differences due to different configurations or performances, including one or more processors (Central Processing Units, CPU) 401 and one or more memories 402, wherein the memory 402 stores at least one program code, and the at least one program code is loaded and executed by the processor 401 to realize the above-mentioned fault simulation method for the front oxygen sensor. Of course, the computer device 400 also has a wired or wireless network interface, a keyboard, and an input and output interface, etc. to perform input and output, and the computer device 400 also includes other components for realizing the functions of the device, which will not be described again here.

[0138] In some embodiments, the present application also provides a computer readable storage medium, for example, a memory including program code, which can be executed by the processor in the computer device to complete the above-mentioned fault simulation method for the front oxygen sensor. For example, the computer readable storage medium can be a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a compact disc read-only memory (Compact Disc Read-Only Memory, CD-ROM), a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0139] In some embodiments, the embodiments of the present application also provide a computer program product or computer program, which comprises computer program code stored in a computer readable storage medium, and a processor of a computer device reads the computer program code from the computer readable storage medium, and the processor executes the computer program code, so that the computer device executes the above-mentioned fault simulation method of the pre-oxygen sensor.

[0140] Those skilled in the art can understand that all or part of the steps of the above-mentioned embodiments can be completed by hardware, or by program instructing relevant hardware to complete, and the program can be stored in a computer readable storage medium. The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0141] The above only describes optional embodiments of the present application and does not limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for simulating the failure of a pre-oxygen sensor, characterized in that, The method includes: Acquire the pump current signal of the pre-oxygen sensor; wherein the pump current signal is used to reflect the magnitude of the current flowing through the pump battery of the pre-oxygen sensor; The pump current signal is converted into the air-fuel ratio of the mixture to obtain the first air-fuel ratio; The first air-fuel ratio is corrected based on the cross-sensitivity correction coefficient and the air-fuel ratio offset correction coefficient to obtain the second air-fuel ratio; wherein, the cross-sensitivity correction coefficient is used to eliminate the measurement deviation related to the front oxygen sensor, and the air-fuel ratio offset correction coefficient is used to eliminate the system deviation related to the engine. When simulating a bilateral delay fault of the pre-oxygen sensor, a first modified value of the calibrable parameter is obtained, and a first fault simulation signal is output according to the first delay time indicated by the first modified value. Wherein, the first fault simulation signal is the second air-fuel ratio after bilateral delay processing; the bilateral delay processing means that when the value of the second air-fuel ratio increases or decreases, the second air-fuel ratio is output after the first delay time.

2. The method according to claim 1, characterized in that, The method further includes: Obtain the reciprocal of the second air-fuel ratio to obtain the first basic parameter for fuel injection control; The bilateral delay processing refers to outputting the first basic parameter after a delay time, whether the value of the first basic parameter increases or decreases.

3. The method according to claim 1, characterized in that, The method further includes: When simulating a one-sided delay fault of the pre-oxygen sensor, if the preset triggering condition is met, the second air-fuel ratio is adjusted based on the adjustment factor to fit the target air-fuel ratio, thereby obtaining the third air-fuel ratio. Obtain the second modified value of the calibrable parameter, and output the second fault simulation signal according to the second delay time indicated by the second modified value; Wherein, the second fault simulation signal is the third air-fuel ratio after unilateral delay processing; the unilateral delay processing means that when the value of the third air-fuel ratio increases or decreases, the third air-fuel ratio is output after the second delay time.

4. The method according to claim 1, characterized in that, The method further includes: When simulating the instantaneous response failure of the front oxygen sensor, the operating parameters of the engine are acquired, and a calibrable correction coefficient is determined based on the operating parameters; wherein, the correction coefficient is used to adjust the rate of change of the second air-fuel ratio; A multiplication operation is performed on the second air-fuel ratio and the correction coefficient to obtain the instantaneous response fault curve with respect to the air-fuel ratio.

5. The method according to claim 4, characterized in that, The step of determining the calibrable correction coefficient based on the operating condition parameters includes: The correction coefficient corresponding to the operating parameters is determined by querying a calibrable mapping table; wherein the mapping table is used to store the correspondence between the engine's operating parameters and the correction coefficients.

6. The method according to claim 4, characterized in that, The method further includes: If the preset triggering conditions are met, the fourth air-fuel ratio is adjusted based on the adjustment factor to fit the target air-fuel ratio, thus obtaining the fifth air-fuel ratio. The fourth air-fuel ratio is the product of the second air-fuel ratio and the correction coefficient.

7. The method according to claim 3 or 6, characterized in that, The process of determining the regulation factor includes: Obtain the absolute value of the difference between the second air-fuel ratio and the target air-fuel ratio; The adjustment factor is obtained by performing a proportional-integral-derivative PID control operation based on the absolute value.

8. A fault simulation device for a pre-oxygen sensor, characterized in that, The device includes: The first acquisition module is configured to acquire the pump current signal of the pre-oxygen sensor; wherein the pump current signal is used to reflect the magnitude of the current flowing through the pump battery of the pre-oxygen sensor. The second acquisition module is configured to convert the pump current signal into an air-fuel ratio of the mixture to obtain a first air-fuel ratio; The correction module is configured to correct the first air-fuel ratio based on a cross-sensitivity correction coefficient and an air-fuel ratio offset correction coefficient to obtain a second air-fuel ratio; wherein the cross-sensitivity correction coefficient is used to eliminate measurement deviations related to the front oxygen sensor, and the air-fuel ratio offset correction coefficient is used to eliminate system deviations related to the engine. The first calibration module is configured to acquire a first modified value of the calibrable parameter when simulating a bilateral delay fault of the pre-oxygen sensor; The fault simulation module is configured to output a first fault simulation signal according to a first delay time indicated by the first modified value when simulating the bilateral delay fault. Wherein, the first fault simulation signal is the second air-fuel ratio after bilateral delay processing; the bilateral delay processing means that when the value of the second air-fuel ratio increases or decreases, the second air-fuel ratio is output after the first delay time.

9. A computer device, characterized in that, The device includes a processor and a memory, the memory storing at least one piece of program code, which is loaded and executed by the processor to implement the fault simulation method for the pre-oxygen sensor as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The storage medium stores at least one piece of program code, which is loaded and executed by a processor to implement the fault simulation method for the pre-oxygen sensor as described in any one of claims 1 to 7.

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