EGR Module Pressure Sensor Detection Method, Device, Vehicle and Storage Medium

Abstract

The present invention discloses a method, device, vehicle and storage medium for detecting a pressure sensor of an EGR module. The method for detecting the pressure sensor of the EGR module includes: when the engine speed, engine load, engine speed change rate and engine load change rate meet the set conditions, obtaining the air flow rate flowing into the EGR module and the pressure value in front of the throttle valve; determining an estimated pressure value at the throat based on the air flow rate flowing into the EGR module and the pressure value in front of the throttle valve; obtaining the current pressure value detected by the pressure sensor at the throat, and determining the state of the pressure sensor at the throat of the EGR module according to the current pressure value and the estimated pressure value. The present invention realizes accurate detection of the pressure sensor at the throat of the EGR module, and improves the detection credibility of the pressure sensor at the throat of the EGR module.

Description

Technical Field

[0001] The present invention relates to the technical field of EGR module detection, and particularly to a method and device for detecting a pressure sensor of an EGR module, a vehicle, and a storage medium. Background Art

[0002] The exhaust gas recirculation system (EGR) recirculates a small portion of the exhaust gas generated by a diesel engine or a gasoline engine back into the cylinder. Currently, the pressure sensor at the throat of the EGR module can be compared with the pressure before the throttle valve to determine whether a fault is reported by the pressure sensor at the throat. However, the existing solution only reports a fault when the pressure of the pressure sensor at the throat is greater than the pressure before the throttle valve, resulting in poor diagnostic accuracy and an overly large diagnostic range when the throttle throttle loss is large. Summary of the Invention

[0003] The present invention provides a method and device for detecting a pressure sensor of an EGR module, a vehicle, and a storage medium to solve the problems of poor diagnostic accuracy of the pressure sensor at the throat of the current EGR module and even worse diagnostic credibility when the throttle throttle loss is large.

[0004] According to an aspect of the present invention, there is provided a method for detecting a pressure sensor of an EGR module, the method for detecting a pressure sensor of an EGR module comprising:

[0005] When the engine speed, engine load, engine speed change rate, and engine load change rate meet set conditions, obtain the air flow rate flowing into the EGR module and the pressure value before the throttle valve;

[0006] Based on the air flow rate flowing into the EGR module and the pressure value before the throttle valve, determine the estimated pressure value at the throat;

[0007] Obtain the current pressure value detected by the pressure sensor at the throat, and determine the state of the pressure sensor at the throat of the EGR module according to the current pressure value and the estimated pressure value.

[0008] Optionally, the engine speed, engine load, engine speed change rate, and engine load change rate meeting the set conditions include:

[0009] The engine speed is within a set speed range, the engine load is within a set load range, the engine speed change rate is less than a set speed change rate threshold, and the engine load change rate is less than a set load change rate threshold.

[0010] Optionally, before determining the estimated pressure value at the throat based on the air flow rate flowing into the EGR module and the pressure value before the throttle valve, further includes:

[0011] Obtain the effective flow diameter and effective flow area at the current throttle opening, the pipe diameters before the throttle and at the gas inlet point, the throat diameter, the throat cross-sectional area, the discharge coefficient of the throat, the discharge coefficient of the throttle, the first compressibility coefficient, and the second compressibility coefficient;

[0012] Obtain the excess air coefficient and the stoichiometric air-fuel ratio of the current engine fuel, and determine the air-fuel ratio correction coefficient according to the excess air coefficient and the stoichiometric air-fuel ratio;

[0013] Based on the air flow rate flowing into the EGR module and the pressure value before the throttle, determine the estimated pressure value at the throat, including:

[0014] Based on the air flow rate flowing into the EGR module, the pressure value before the throttle, the effective flow diameter and effective flow area at the current throttle opening, the pipe diameters before the throttle and at the gas inlet point, the throat diameter, the throat cross-sectional area, the discharge coefficient of the throat, the discharge coefficient of the throttle, the first compressibility coefficient, the second compressibility coefficient, and the air-fuel ratio correction coefficient, determine the estimated pressure value at the throat.

[0015] Optionally, the determining the air-fuel ratio correction coefficient according to the excess air coefficient and the stoichiometric air-fuel ratio includes:

[0016] Determine the air-fuel ratio correction coefficient based on the following formula, specifically:

[0017]

[0018] where Fac AFR is the air-fuel ratio correction coefficient; λ is the excess air coefficient; AFR is the stoichiometric air-fuel ratio.

[0019] Optionally, the determining the estimated pressure value at the throat based on the air flow rate flowing into the EGR module, the pressure value before the throttle, the effective flow diameter and effective flow area at the current throttle opening, the pipe diameters before the throttle and at the gas inlet point, the throat diameter, the throat cross-sectional area, the discharge coefficient of the throat, the discharge coefficient of the throttle, the first compressibility coefficient, the second compressibility coefficient, and the air-fuel ratio correction coefficient includes:

[0020] Determine the estimated pressure value at the throat based on the following formula, specifically:

[0021]

[0022] where p noz_Sim is the estimated pressure value; q air_VE is the air flow rate flowing into the EGR module; p0 is the pressure value before the throttle; d nozis the throat diameter; A noz is the throat cross-sectional area; d TV is the effective flow diameter at the current throttle opening; A TV is the effective flow area at the current throttle opening; D is the pipe diameter before the throttle and at the gas inlet point; C0 is the discharge coefficient of the throttle; ε0 is the first compressibility coefficient; C1 is the discharge coefficient of the throat; ε1 is the second compressibility coefficient; R is the gas constant; T0 is the temperature value before the throttle; M is the molar mass of air.

[0023] Optionally, determining the pressure sensor state at the throat of the EGR module according to the current pressure value and the estimated pressure value includes:

[0024] If the current pressure value is greater than the estimated pressure value, and the absolute value of the difference between the current pressure value and the estimated pressure value is greater than the first preset pressure limit, it is determined that the pressure sensor state at the throat of the EGR module is a fault beyond the dynamic diagnosis lower limit;

[0025] If the current pressure value is less than the estimated pressure value, and the absolute value of the difference between the current pressure value and the estimated pressure value is greater than the second preset pressure limit, it is determined that the pressure sensor state at the throat of the EGR module is a fault beyond the dynamic diagnosis upper limit.

[0026] According to another aspect of the present invention, there is provided a pressure sensor detection device for an EGR module, and the pressure sensor detection device for the EGR module includes:

[0027] An information acquisition module, configured to acquire the air flow rate flowing into the EGR module and the pressure value before the throttle when the engine speed, engine load, engine speed change rate, and engine load change rate meet the set conditions;

[0028] An estimated pressure value calculation module, configured to determine the estimated pressure value at the throat based on the air flow rate flowing into the EGR module and the pressure value before the throttle;

[0029] A pressure sensor state determination module, configured to acquire the current pressure value detected by the pressure sensor at the throat, and determine the pressure sensor state at the throat of the EGR module according to the current pressure value and the estimated pressure value.

[0030] Optionally, the engine speed, engine load, engine speed change rate, and engine load change rate meeting the set conditions specifically are:

[0031] The engine speed is within the set speed range, the engine load is within the set load range, the engine speed change rate is less than the set engine speed change rate threshold, and the engine load change rate is less than the set engine load change rate threshold.

[0032] According to another aspect of the present invention, there is provided a vehicle, the vehicle comprising:

[0033] At least one processor; and

[0034] A memory communicatively connected to the at least one processor; wherein,

[0035] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the EGR module pressure sensor detection method according to any embodiment of the present invention.

[0036] According to another aspect of the present invention, there is provided a computer-readable storage medium storing computer instructions for causing a processor to implement the EGR module pressure sensor detection method according to any embodiment of the present invention when executed.

[0037] The technical solution of the embodiment of the present invention obtains the air flow rate flowing into the EGR module and the pressure value in front of the throttle when the engine speed, engine load, engine speed change rate, and engine load change rate meet the set conditions; determines the estimated pressure value at the throat based on the air flow rate flowing into the EGR module and the pressure value in front of the throttle; obtains the current pressure value detected by the pressure sensor at the throat, and determines the state of the pressure sensor at the throat of the EGR module according to the current pressure value and the estimated pressure value. The present invention solves the problems of poor diagnostic accuracy of the pressure sensor at the throat of the current EGR module and even worse diagnostic credibility when the throttle throttling loss is large, realizes accurate detection of the pressure sensor at the throat of the EGR module, and improves the detection credibility of the pressure sensor at the throat of the EGR module.

[0038] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. Description of the Drawings

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0040] Figure 1 is a flowchart of a method for detecting an EGR module pressure sensor provided in Embodiment 1 of the present invention;

[0041] Figure 2 is a schematic diagram of the principle structure of an EGR module applicable to the embodiments of the present invention;

[0042] Figure 3 is a flowchart of a method for detecting an EGR module pressure sensor provided in Embodiment 2 of the present invention;

[0043] Figure 4 is a schematic diagram of the structure of a device for detecting an EGR module pressure sensor provided in Embodiment 3 of the present invention;

[0044] Figure 5 is a schematic diagram of the structure of a vehicle for implementing the method for detecting an EGR module pressure sensor according to the embodiments of the present invention. Detailed implementation manners

[0045] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0046] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above accompanying drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0047] Embodiment 1

[0048] Figure 1FIG. 0 is a flowchart of a method for detecting a pressure sensor of an EGR module provided in Embodiment 1 of the present invention. This embodiment is applicable to the situation of accurately diagnosing the state of the pressure sensor at the throat of the EGR module. The method for detecting the pressure sensor of the EGR module can be executed by a detection device for the pressure sensor of the EGR module. The detection device for the pressure sensor of the EGR module can be implemented in the form of hardware and / or software, and the detection device for the pressure sensor of the EGR module can be configured in a vehicle or a post-treatment system of the vehicle. Based on the characteristics of the EGR module of the post-treatment system, the pressure at 10 before the throttle, the pressure at the throat 20, and the pressure at the intake manifold 30 of the EGR module are provided as shown in Figure 2 shown. Continuing to refer to Figure 1 and Figure 2 , the method for detecting the pressure sensor of the EGR module includes:

[0049] S110. When the engine speed, engine load, engine speed change rate, and engine load change rate meet the set conditions, obtain the air flow rate flowing into the EGR module and the pressure value before the throttle.

[0050] Among them, the engine speed, engine load, engine speed change rate, and engine load change rate meeting the set conditions mean that the engine speed is within the set speed range, and the engine load is within the set load range, and the engine speed change rate is less than the set engine speed change rate threshold, and the engine load change rate is less than the set engine load change rate threshold. The set speed range, set load range, set engine speed change rate threshold, and set engine load change rate threshold can be selected and set by those skilled in the art according to the actual situation of the engine, and this embodiment does not make any restrictions on this.

[0051] It can be understood that when the engine speed is within the set speed range, and the engine load is within the set load range, and the engine speed change rate is less than the set engine speed change rate threshold, and the engine load change rate is less than the set engine load change rate threshold, the engine is in a steady-state operating condition.

[0052] Continuing to refer to Figure 2 , according to the hardware characteristics of the EGR module and the law of conservation of mass, when the engine is in a steady-state operating condition, then

[0053] q air_VE =q air_0 =q air_1 (1)

[0054] Among them, q air_VE is the air flow rate flowing into the EGR module; q air_0 is the air flow rate at the throttle; q air_1 is the air flow rate at the throat.

[0055] It is known that the air flow rate flowing into the EGR module can be obtained by means of existing calculation methods such as the speed density method, and the present embodiment does not impose any restrictions on its acquisition means.

[0056] The air density in front of the throttle valve, the pressure value in front of the throttle valve, and the gas density at the gas inlet point can all be obtained through existing sensors or other calculation methods, and the present embodiment does not impose any restrictions on its acquisition means.

[0057] S120. Determine the estimated pressure value at the throat based on the air flow rate flowing into the EGR module and the pressure value in front of the throttle valve.

[0058] Specifically, before determining the estimated pressure value at the throat based on the air flow rate flowing into the EGR module and the pressure value in front of the throttle valve, it further includes: obtaining the effective flow diameter and effective flow area at the current throttle valve opening, the pipe diameters in front of the throttle valve and at the gas inlet point, the throat diameter, the throat cross-sectional area, the discharge coefficient of the throat, the discharge coefficient of the throttle valve, the first compressibility coefficient, and the second compressibility coefficient; obtaining the excess air coefficient and the equivalent air-fuel ratio of the current engine fuel, and determining the air-fuel ratio correction coefficient according to the excess air coefficient and the equivalent air-fuel ratio; further, based on the air flow rate flowing into the EGR module, the pressure value in front of the throttle valve, the effective flow diameter and effective flow area at the current throttle valve opening, the pipe diameters in front of the throttle valve and at the gas inlet point, the throat diameter, the throat cross-sectional area, the discharge coefficient of the throat, the discharge coefficient of the throttle valve, the first compressibility coefficient, the second compressibility coefficient, and the air-fuel ratio correction coefficient, determine the estimated pressure value at the throat.

[0059] It is known that the air-fuel ratio correction coefficient is determined based on the following formula, specifically:

[0060]

[0061] where Fac AFR is the air-fuel ratio correction coefficient; λ is the excess air coefficient; AFR is the equivalent air-fuel ratio.

[0062] In this embodiment, the estimated pressure value at the throat is determined based on the following formula, specifically:

[0063]

[0064] where p noz_Sim is the estimated pressure value; q air_VE is the air flow rate flowing into the EGR module; p0 is the pressure value in front of the throttle valve; d noz is the throat diameter; A noz is the throat cross-sectional area; d TVis the effective flow diameter at the current throttle opening; A TV is the effective flow area at the current throttle opening; D is the pipe diameter before the throttle and at the gas inlet point; C0 is the discharge coefficient of the throttle; ε0 is the first compressibility coefficient; C1 is the discharge coefficient of the throat; ε1 is the second compressibility coefficient; R is the gas constant; T0 is the temperature value before the throttle; M is the molar mass of air.

[0065] S130. Obtain the current pressure value detected by the pressure sensor at the throat, and determine the state of the pressure sensor at the throat of the EGR module according to the current pressure value and the estimated pressure value.

[0066] Among them, the state of the pressure sensor at the throat of the EGR module includes a normal state, a fault exceeding the dynamic diagnosis upper limit, and a fault exceeding the dynamic diagnosis lower limit. When the state of the pressure sensor at the throat of the EGR module is a fault exceeding the dynamic diagnosis upper limit, it means that the pressure sensor at the throat of the EGR module exceeds the maximum detectable pressure value when dynamically detecting the pressure value at the throat; when the state of the pressure sensor at the throat of the EGR module is a fault exceeding the dynamic diagnosis lower limit, it means that the pressure sensor at the throat of the EGR module cannot detect a value less than the minimum pressure value when dynamically detecting the pressure value at the throat.

[0067] Specifically, if the current pressure value is greater than the estimated pressure value, and the absolute value of the difference between the current pressure value and the estimated pressure value is greater than the first preset pressure limit, it is determined that the state of the pressure sensor at the throat of the EGR module is a fault exceeding the dynamic diagnosis lower limit; if the current pressure value is less than the estimated pressure value, and the absolute value of the difference between the current pressure value and the estimated pressure value is greater than the second preset pressure limit, it is determined that the state of the pressure sensor at the throat of the EGR module is a fault exceeding the dynamic diagnosis upper limit.

[0068] The technical solution of the embodiment of the present invention, when the engine speed, engine load, engine speed change rate, and engine load change rate meet the set conditions, obtains the air flow rate flowing into the EGR module and the pressure value before the throttle; determines the estimated pressure value at the throat based on the air flow rate flowing into the EGR module and the pressure value before the throttle; obtains the current pressure value detected by the pressure sensor at the throat, and determines the state of the pressure sensor at the throat of the EGR module according to the current pressure value and the estimated pressure value. The present invention solves the problems of poor diagnostic accuracy of the pressure sensor at the throat of the current EGR module and even worse diagnostic credibility when the throttle throttling loss is large, realizes the accurate detection of the pressure sensor at the throat of the EGR module, and improves the detection credibility of the pressure sensor at the throat of the EGR module.

[0069] Embodiment Two

[0070] Figure 3 The flowchart of a method for detecting the pressure sensor of the EGR module provided in the second embodiment of the present invention. On the basis of the above embodiments, an optional implementation manner is provided. As Figure 3 shown, the method for detecting the pressure sensor of the EGR module includes:

[0071] S210. When the engine speed is within the set speed range, the engine load is within the set load range, the engine speed change rate is less than the set engine speed change rate threshold, and the engine load change rate is less than the set engine load change rate threshold, obtain the air flow rate flowing into the EGR module and the pressure value in front of the throttle valve.

[0072] S220. Obtain the effective flow diameter and effective flow area at the current throttle valve opening, the pipe diameters in front of the throttle valve and at the gas inlet point, the throat diameter, the throat cross-sectional area, the discharge coefficient of the throat, the discharge coefficient of the throttle valve, the first compressibility coefficient, and the second compressibility coefficient.

[0073] Among them, the first compressibility coefficient can be obtained by looking up the interpolation table of the fixed corresponding relationship with the and at the previous moment, or it can be omitted and calculated according to 1. This embodiment does not make any restrictions on this.

[0074] The second compressibility coefficient can be obtained by looking up the interpolation table of the fixed corresponding relationship with the and at the previous moment, or it can be omitted and calculated according to 1. This embodiment does not make any restrictions on this.

[0075] On the basis of the above embodiments, based on the hardware characteristics of the existing EGR module, obtain the pressure value in front of the throttle valve, the air density in front of the throttle valve, the effective flow diameter and effective flow area at the current throttle valve opening, the pipe diameters in front of the throttle valve and at the gas inlet point, the discharge coefficient of the throttle valve, and the first compressibility coefficient. Then, the air flow rate at the throttle valve can be calculated by the following formula:

[0076]

[0077] Among them, p0 is the pressure value in front of the throttle valve; d TV is the effective flow diameter at the current throttle valve opening; A TV is the effective flow area at the current throttle valve opening; D is the pipe diameter in front of the throttle valve and at the gas inlet point; C0 is the discharge coefficient of the throttle valve; ε0 is the first compressibility coefficient; ρ0 is the air density in front of the throttle valve; p v is the virtual pressure value at the gas inlet point.

[0078] It can be understood that in Formula (4), the virtual pressure value at the gas inlet point is an unknown quantity. By combining Formula (1) and Formula (4), the virtual pressure value at the gas inlet point can be calculated.

[0079] S230. Obtain the excess air coefficient and the stoichiometric air-fuel ratio of the current engine fuel, and determine the air-fuel ratio correction coefficient based on the excess air coefficient and the stoichiometric air-fuel ratio.

[0080] It is known that the air-fuel ratio correction coefficient is determined based on the following formula, specifically:

[0081]

[0082] where Fac AFR is the air-fuel ratio correction coefficient; λ is the excess air coefficient; AFR is the stoichiometric air-fuel ratio.

[0083] S240. Based on the air flow rate flowing into the EGR module, the pressure value in front of the throttle valve, the effective flow diameter and the effective flow area at the current throttle valve opening, the pipe diameters in front of the throttle valve and at the gas inlet point, the throat diameter, the throat cross-sectional area, the discharge coefficient of the throat, the discharge coefficient of the throttle valve, the first compressibility coefficient, the second compressibility coefficient, and the air-fuel ratio correction coefficient, determine the estimated pressure value at the throat.

[0084] Based on the hardware characteristics of the existing EGR module in the above embodiments, obtain the gas density at the gas inlet point, the throat diameter, the throat cross-sectional area, the discharge coefficient of the throat, and the second compressibility coefficient, and based on the virtual pressure value at the gas inlet point, the gas density at the gas inlet point, the throat diameter, the throat cross-sectional area, the discharge coefficient of the throat, the second compressibility coefficient, and the air-fuel ratio correction coefficient, determine the air flow rate at the throat based on the following formula, specifically:

[0085]

[0086] where ρ v is the gas density at the gas inlet point; d noz is the throat diameter; A noz is the throat cross-sectional area; C1 is the discharge coefficient of the throat; ε1 is the second compressibility coefficient.

[0087] By combining formula (2), formula (3) and formula (4), the estimated pressure value at the throat can be obtained, that is, based on the air flow rate flowing into the EGR module, the pre-throttle pressure value, the effective flow diameter and effective flow area at the current throttle opening, the pipe diameter before the throttle and the gas inlet point, the throat diameter, the throat cross-sectional area, the throat outflow coefficient, the throttle outflow coefficient, the first compressibility coefficient, the second compressibility coefficient and the air-fuel ratio correction coefficient, the estimated pressure value at the throat is determined, specifically referring to formula (5):

[0088]

[0089] Where R is the gas constant; T0 is the temperature before the throttle valve; M is the molar mass of air.

[0090] S250: If the current pressure value is greater than the estimated pressure value, and the absolute value of the difference between the current pressure value and the estimated pressure value is greater than a first preset pressure limit, it is determined that the state of the pressure sensor at the throat of the EGR module is a fault exceeding a dynamic diagnosis lower limit;

[0091] If the current pressure value is less than the estimated pressure value, and the absolute value of the difference between the current pressure value and the estimated pressure value is greater than a second preset pressure limit, it is determined that the state of the pressure sensor at the throat of the EGR module is a fault exceeding the dynamic diagnosis upper limit.

[0092] The technical solution of the present application utilizes the application characteristics of the EGR module air flow meter on the engine, and the mass balance and energy balance principles at various positions in front of the throttle, at the throat and at the intake manifold. Within a small throttle opening range or when there is a large pressure loss in the intake manifold, it is still possible to accurately determine the fault of the pressure sensor at the throat of the EGR module, thereby achieving accurate diagnosis of the status of the pressure sensor at the throat of the EGR module.

[0093] Embodiment 3

[0094] Figure 4 This is a schematic diagram of the structure of an EGR module pressure sensor detection device provided by the third embodiment of the present invention. Figure 4 As shown, the EGR module pressure sensor detection device includes:

[0095] An information acquisition module 410 is used to acquire the air flow rate flowing into the EGR module and the pre-throttle pressure value when the engine speed, the engine load, the engine speed change rate and the engine load change rate meet the set conditions;

[0096] An estimated pressure value calculation module 420 is used to determine an estimated pressure value at the throat based on the air flow rate flowing into the EGR module and the pre-throttle pressure value;

[0097] A pressure sensor status determination module 430, configured to obtain a current pressure value detected by the pressure sensor at the throat, and determine the status of the pressure sensor at the throat of the EGR module according to the current pressure value and the estimated pressure value.

[0098] Optionally, the engine speed, engine load, engine speed change rate, and engine load change rate satisfy set conditions, specifically:

[0099] The engine speed is within a set speed range, the engine load is within a set load range, the engine speed change rate is less than a set engine speed change rate threshold, and the engine load change rate is less than a set engine load change rate threshold.

[0100] Optionally, the EGR module pressure sensor detection device further includes:

[0101] A first coefficient acquisition module, which acquires an effective flow diameter and effective flow area at the current throttle opening, pipe diameters before the throttle and at the gas inlet point, throat diameter, throat cross-sectional area, discharge coefficient of the throat, discharge coefficient of the throttle, first compressibility coefficient, and second compressibility coefficient;

[0102] A second coefficient acquisition module, configured to obtain an excess air coefficient and an equivalent air-fuel ratio of the current engine fuel, and determine an air-fuel ratio correction coefficient according to the excess air coefficient and the equivalent air-fuel ratio;

[0103] Based on the air flow rate flowing into the EGR module and the pressure value before the throttle, determine the estimated pressure value at the throat, specifically:

[0104] Based on the air flow rate flowing into the EGR module, the pressure value before the throttle, the effective flow diameter and effective flow area at the current throttle opening, pipe diameters before the throttle and at the gas inlet point, the throat diameter, the throat cross-sectional area, the discharge coefficient of the throat, the discharge coefficient of the throttle, the first compressibility coefficient, the second compressibility coefficient, and the air-fuel ratio correction coefficient, determine the estimated pressure value at the throat.

[0105] Optionally, determining the air-fuel ratio correction coefficient according to the excess air coefficient and the equivalent air-fuel ratio includes:

[0106] Determine the air-fuel ratio correction coefficient based on the following formula, specifically:

[0107]

[0108] where Fac AFR is the air-fuel ratio correction coefficient; λ is the excess air coefficient; AFR is the equivalent air-fuel ratio.

[0109] Optionally, determine the estimated pressure value at the throttle throat based on the air flow rate flowing into the EGR module, the pressure value in front of the throttle valve, the effective flow diameter and the effective flow area at the current throttle valve opening, the pipe diameters in front of the throttle valve and at the gas inlet point, the throttle throat diameter, the throttle throat cross-sectional area, the discharge coefficient of the throttle throat, the discharge coefficient of the throttle valve, the first compressibility coefficient, the second compressibility coefficient, and the air-fuel ratio correction coefficient. Specifically, it is used for:

[0110] Determine the estimated pressure value at the throttle throat based on the following formula, specifically:

[0111]

[0112] where p noz_Sim is the estimated pressure value; q air_VE is the air flow rate flowing into the EGR module; p0 is the pressure value in front of the throttle valve; d noz is the throttle throat diameter; A noz is the throttle throat cross-sectional area; d TV is the effective flow diameter at the current throttle valve opening; A TV is the effective flow area at the current throttle valve opening; D is the pipe diameter in front of the throttle valve and at the gas inlet point; C0 is the discharge coefficient of the throttle valve; ε0 is the first compressibility coefficient; C1 is the discharge coefficient of the throttle throat; ε1 is the second compressibility coefficient; R is the gas constant; T0 is the temperature value in front of the throttle valve; M is the molar mass of air.

[0113] Optionally, the pressure sensor status determination module 430 is specifically used for:

[0114] If the current pressure value is greater than the estimated pressure value, and the absolute value of the difference between the current pressure value and the estimated pressure value is greater than the first preset pressure limit, determine that the pressure sensor status at the throttle throat of the EGR module is a fault exceeding the dynamic diagnosis lower limit;

[0115] If the current pressure value is less than the estimated pressure value, and the absolute value of the difference between the current pressure value and the estimated pressure value is greater than the second preset pressure limit, determine that the pressure sensor status at the throttle throat of the EGR module is a fault exceeding the dynamic diagnosis upper limit.

[0116] The EGR module pressure sensor detection device provided by the embodiments of the present invention can execute the EGR module pressure sensor detection method provided by any embodiment of the present invention, and has the corresponding functional modules and beneficial effects for executing the EGR module pressure sensor detection method.

[0117] Embodiment 4

[0118] Figure 5 FIG. 510 shows a schematic structural diagram of a vehicle that can be used to implement an embodiment of the present invention. The vehicle includes various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The vehicle also includes various forms of mobile devices, such as personal digital processors, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0119] As Figure 5 shown, the vehicle 510 includes at least one processor 511, and a memory communicatively connected to the at least one processor 511, such as read-only memory (ROM) 512, random access memory (RAM) 513, etc. The memory stores a computer program executable by the at least one processor. The processor 511 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 512 or the computer program loaded from the storage unit 518 into the random access memory (RAM) 513. In the RAM 513, various programs and data required for the operation of the vehicle 510 can also be stored. The processor 511, ROM 512, and RAM 513 are connected to each other through a bus 514. An input / output (I / O) interface 515 is also connected to the bus 514.

[0120] Multiple components in the vehicle 510 are connected to the I / O interface 515, including: an input unit 516, such as a keyboard, a mouse, etc.; an output unit 517, such as various types of displays, speakers, etc.; a storage unit 518, such as a magnetic disk, an optical disk, etc.; and a communication unit 519, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 519 allows the vehicle 510 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0121] The processor 511 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the processor 511 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 511 executes the various methods and processes described above, such as the EGR module pressure sensor detection method.

[0122] In some embodiments, the EGR module pressure sensor detection method may be implemented as a computer program tangibly embodied in a computer-readable storage medium, such as storage unit 518. In some embodiments, part or all of the computer program may be loaded and / or installed onto vehicle 510 via ROM 512 and / or communication unit 519. When the computer program is loaded into RAM 513 and executed by processor 511, one or more steps of the EGR module pressure sensor detection method described above may be performed. Alternatively, in other embodiments, processor 511 may be configured to perform the EGR module pressure sensor detection method by any other suitable means (e.g., by means of firmware).

[0123] The various implementations of the systems and techniques described above in this document may be implemented in digital electronic circuitry, integrated circuit systems, field programmable gate arrays (FPGA), application specific integrated circuits (ASIC), application specific standard products (ASSP), systems on a chip (SOC), complex programmable logic devices (CPLD), computer hardware, firmware, software, and / or combinations thereof. These various implementations may include: being implemented in one or more computer programs that may be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a special-purpose or general-purpose programmable processor that receives data and instructions from a storage system, at least one input device, and at least one output device, and transmits the data and instructions to the storage system, the at least one input device, and the at least one output device.

[0124] The computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that the computer programs, when executed by the processor, cause the functions / operations specified in the flowchart and / or block diagram to be implemented. The computer programs may be executed entirely on the machine, partially on the machine, as a stand-alone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0125] In the context of the present invention, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer-readable storage medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, the computer-readable storage medium can be a machine-readable signal medium. More specific examples of the machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0126] In order to provide interaction with a user, the systems and techniques described herein can be implemented on a vehicle that has: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the vehicle. Other kinds of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, speech input, or tactile input).

[0127] The systems and techniques described herein can be implemented in a computing system that includes backend components (such as, for example, a data server), or a computing system that includes middleware components (such as, for example, an application server), or a computing system that includes frontend components (such as, for example, a user computer having a graphical user interface or a web browser through which the user can interact with an implementation of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system can be interconnected by any form or medium of digital data communication (such as, for example, a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0128] A computing system may include a client and a server. The client and the server are generally far from each other and usually interact via a communication network. The client-server relationship is created by computer programs running on respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or a cloud host, which is a host product in the cloud computing service system, solving the defects of difficult management and weak business scalability existing in traditional physical hosts and VPS services.

[0129] It should be understood that various forms of processes shown above can be used, steps can be reordered, added or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solution of the present invention can be achieved, and no limitation is made herein.

[0130] The above specific embodiments do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for detecting the pressure sensor of an EGR module, characterized in that, Including: When the engine speed, engine load, engine speed change rate, and engine load change rate meet the set conditions, obtain the air flow rate flowing into the EGR module and the pressure value in front of the throttle valve; wherein, the engine speed, engine load, engine speed change rate, and engine load change rate meeting the set conditions include: the engine speed is within the set speed range, the engine load is within the set load range, the engine speed change rate is less than the set engine speed change rate threshold, and the engine load change rate is less than the set engine load change rate threshold; Obtain the effective flow diameter and effective flow area at the current throttle valve opening, the pipe diameters in front of the throttle valve and at the gas inlet point, the throat diameter, the throat cross-sectional area, the discharge coefficient of the throat, the discharge coefficient of the throttle valve, the first compressibility coefficient, and the second compressibility coefficient; Obtain the excess air coefficient and the equivalent air-fuel ratio of the current engine fuel, and determine the air-fuel ratio correction coefficient according to the excess air coefficient and the equivalent air-fuel ratio; Determine the estimated pressure value at the throat based on the air flow rate flowing into the EGR module and the pressure value in front of the throttle valve; wherein, determining the estimated pressure value at the throat based on the air flow rate flowing into the EGR module and the pressure value in front of the throttle valve includes: based on the air flow rate flowing into the EGR module, the pressure value in front of the throttle valve, the effective flow diameter and effective flow area at the current throttle valve opening, the pipe diameters in front of the throttle valve and at the gas inlet point, the throat diameter, the throat cross-sectional area, the discharge coefficient of the throat, the discharge coefficient of the throttle valve, the first compressibility coefficient, the second compressibility coefficient, and the air-fuel ratio correction coefficient, determine the estimated pressure value at the throat; Obtain the current pressure value detected by the pressure sensor at the throat, and determine the state of the pressure sensor at the throat of the EGR module according to the current pressure value and the estimated pressure value.

2. The method for detecting the EGR module pressure sensor according to claim 1, wherein The determining the air-fuel ratio correction coefficient according to the excess air coefficient and the equivalent air-fuel ratio includes: Determine the air-fuel ratio correction coefficient based on the following formula, specifically: Among them, Fac AFR is the air-fuel ratio correction coefficient; λ is the excess air coefficient; AFR is the equivalent air-fuel ratio.

3. The EGR module pressure sensor detection method according to claim 2, wherein, The determining the estimated pressure value at the throat based on the air flow rate flowing into the EGR module, the pressure value in front of the throttle valve, the effective flow diameter and effective flow area at the current throttle valve opening, the pipe diameters in front of the throttle valve and at the gas inlet point, the throat diameter, the throat cross-sectional area, the discharge coefficient of the throat, the discharge coefficient of the throttle valve, the first compressibility coefficient, the second compressibility coefficient, and the air-fuel ratio correction coefficient includes: Determine the estimated pressure value at the throat based on the following formula, specifically: where p noz_Sim is the estimated pressure value; q air_VE is the air flow rate into the EGR module; p0 is the pressure value before the throttle valve; d noz is the throat diameter; A noz is the throat cross-sectional area; d TV is the effective flow diameter at the current throttle valve opening; A TV is the effective flow area at the current throttle valve opening; D is the pipeline diameter before the throttle valve and at the gas inlet point; C0 is the discharge coefficient of the throttle valve; ε0 is the first compressibility coefficient; C1 is the discharge coefficient of the throat; ε1 is the second compressibility coefficient; R is the gas constant; T0 is the temperature value before the throttle valve; M is the molar mass of air.

4. The method for detecting an EGR module pressure sensor according to claim 1, wherein The determining the state of the pressure sensor at the throat of the EGR module according to the current pressure value and the estimated pressure value includes: If the current pressure value is greater than the estimated pressure value, and the absolute value of the difference between the current pressure value and the estimated pressure value is greater than the first preset pressure limit value, then determine that the state of the pressure sensor at the throat of the EGR module is a fault beyond the dynamic diagnosis lower limit; If the current pressure value is less than the estimated pressure value, and the absolute value of the difference between the current pressure value and the estimated pressure value is greater than the second preset pressure limit value, it is determined that the pressure sensor state at the throat of the EGR module is a fault beyond the dynamic diagnosis upper limit.

5. An EGR module pressure sensor detection device, characterized in that, Including: An information acquisition module, configured to acquire the air flow rate flowing into the EGR module and the pressure value before the throttle when the engine speed, engine load, engine speed change rate, and engine load change rate meet the set conditions; wherein, the engine speed, engine load, engine speed change rate, and engine load change rate meeting the set conditions include: the engine speed is within the set speed range, the engine load is within the set load range, the engine speed change rate is less than the set engine speed change rate threshold, and the engine load change rate is less than the set engine load change rate threshold; A first coefficient acquisition module, which acquires the effective flow diameter and effective flow area at the current throttle opening, the pipe diameters before the throttle and at the gas inlet point, the throat diameter, the throat cross-sectional area, the discharge coefficient of the throat, the discharge coefficient of the throttle, the first compressibility coefficient, and the second compressibility coefficient; A second coefficient acquisition module, configured to acquire the excess air coefficient and the stoichiometric air-fuel ratio of the current engine fuel, and determine the air-fuel ratio correction coefficient according to the excess air coefficient and the stoichiometric air-fuel ratio; An estimated pressure value calculation module, configured to determine the estimated pressure value at the throat based on the air flow rate flowing into the EGR module and the pressure value before the throttle; wherein, determining the estimated pressure value at the throat based on the air flow rate flowing into the EGR module and the pressure value before the throttle is specifically used for: determining the estimated pressure value at the throat based on the air flow rate flowing into the EGR module, the pressure value before the throttle, the effective flow diameter and effective flow area at the current throttle opening, the pipe diameters before the throttle and at the gas inlet point, the throat diameter, the throat cross-sectional area, the discharge coefficient of the throat, the discharge coefficient of the throttle, the first compressibility coefficient, the second compressibility coefficient, and the air-fuel ratio correction coefficient; A pressure sensor state determination module, configured to acquire the current pressure value detected by the pressure sensor at the throat and determine the pressure sensor state at the throat of the EGR module according to the current pressure value and the estimated pressure value.

6. A vehicle, characterized in that, The vehicle includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and when the computer program is executed by the at least one processor, the at least one processor is enabled to execute the EGR module pressure sensor detection method according to any one of claims 1-4.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for enabling a processor to execute the EGR module pressure sensor detection method according to any one of claims 1-4 when executed.

Images