Range extender misfire diagnosis method, device, equipment and medium

Abstract

The invention provides a range extender misfire diagnosis method, device and equipment and a medium, and relates to the technical field of hybrid electric vehicles. The method comprises the following steps: determining a first rotary change signal corresponding to a target falling edge of the cam shaft based on a target rotary change signal of the rotating shaft; based on the first resolver signal and a target pitch, determining a second resolver signal corresponding to a compression top dead center of a first cylinder in the plurality of cylinders; determining a mapping relation between a current rotary change signal of the rotating shaft and a crankshaft rotation angle of the crankshaft based on the second rotary change signal; based on the mapping relation, the first duration of the power stroke of combustion of the target air cylinder in the multiple air cylinders is determined; and determining whether the range extender is on fire or not based on the first duration. According to the range extender misfire diagnosis method, device and equipment and the medium provided by the invention, the accurate diagnosis of the misfire of the range extender can be realized.

Description

Technical Field

[0001] The present application relates to the technical field of hybrid electric vehicles, and in particular to a range extender misfire diagnosis method, device, equipment and medium. Background Art

[0002] In today's hybrid vehicles with extended-range configuration, the range extender is generally composed of two major assemblies: the engine and the generator. The power stroke of each cylinder of the engine corresponds to a half-turn crankshaft rotation time period Δt. When a misfire occurs in a cylinder of the engine, the corresponding crankshaft rotation angular velocity ω will slow down, the angular acceleration α will become smaller, and the half-turn time period Δt will be significantly shortened. By detecting the size change of Δt, it can be determined whether there is a misfire in this cylinder. The engine crankshaft and other mechanical components (such as flywheels, connecting rods, transmission components, etc.) have certain rotational inertia and elastic characteristics. The sudden change in engine torque caused by misfire will excite the resonance of these mechanical components, resulting in an instantaneous drop in crankshaft speed, followed by reverse-forward reciprocating fluctuations under the action of system inertia, such as Figure 1 ( Figure 1 It is a schematic diagram of the crankshaft speed when the cylinder misfires as provided in the background technology of this application). These resonances will weaken quickly and disappear after the misfire disappears. When the misfire rate increases, the misfire frequency per unit time becomes faster, and the resonance area will gradually overlap with the misfire area. When the resonance direction is the same as the misfire direction, the misfire signal will be strengthened (for example, Δt becomes larger); and when the direction is opposite, the misfire signal will be weakened (for example, Δt becomes larger). When Δt becomes smaller to a certain extent, it will cause the misfire diagnosis to miss the misfire, such as Figure 2 ( Figure 2 (This is a schematic diagram illustrating a missed misfire diagnosis provided in the background technology of this application.) Missed misfire diagnosis at high misfire rates can result in fault codes not being reported and protective measures not being implemented. Continued unburned fuel entering the catalyst can cause afterburning, ultimately damaging the catalyst. Summary of the Invention

[0003] The present application provides a range extender misfire diagnosis method, device, equipment and medium to address the defect of low accuracy in range extender misfire diagnosis in the prior art and achieve accurate diagnosis of range extender misfire.

[0004] In a first aspect, the present application provides a method for diagnosing misfire in a range extender, wherein the range extender includes an engine and a generator, wherein the engine includes a camshaft, a crankshaft, and a plurality of cylinders, and the generator includes a rotating shaft, wherein the camshaft is connected to the crankshaft, wherein the plurality of cylinders are connected to the crankshaft, and wherein the rotating shaft is connected to the crankshaft; the method includes:

[0005] Determining a first resolver signal corresponding to a target falling edge of the camshaft based on a target resolver signal of the rotating shaft; the target resolver signal is a set of resolver signals corresponding to a rising edge and a falling edge of the camshaft;

[0006] determining, based on the first resolver signal and a target tooth pitch, a second resolver signal corresponding to a compression top dead center of a first cylinder among the plurality of cylinders; wherein a fixed tooth pitch relationship exists between the target falling edge and the compression top dead center of the first cylinder, and the target tooth pitch is a distance between the target falling edge and the compression top dead center of the first cylinder;

[0007] determining, based on the second resolver signal, a mapping relationship between a current resolver signal of the rotating shaft and a crankshaft angle of the crankshaft;

[0008] Determining a first duration of a power stroke of combustion of a target cylinder among the plurality of cylinders based on the mapping relationship; the target cylinder is a cylinder currently burning among the plurality of cylinders;

[0009] Based on the first time period, it is determined whether the range extender misfires.

[0010] Optionally, determining the first resolver signal corresponding to the target falling edge of the camshaft based on the target resolver signal of the rotating shaft includes:

[0011] When a rising edge or a falling edge of the camshaft is identified for the first time, the resolver signal at this time is recorded as a first target signal, and a module where the first target signal is located is defined as a first module;

[0012] determining a plurality of target signals in the target resolver signal corresponding to a rising edge or a falling edge appearing when the camshaft rotates one circle starting from the first target signal, and determining a module where each target signal in the plurality of target signals is located based on the first module;

[0013] Determining a target camshaft angle based on the multiple target signals and the module where each target signal is located; the target camshaft angle is the camshaft angle corresponding to the wide side and the camshaft angle corresponding to the narrow side of the camshaft;

[0014] Based on the target camshaft rotation angle, the target falling edge is determined, and a resolver signal corresponding to the target falling edge is used as the first resolver signal.

[0015] Optionally, determining the target falling edge based on the target camshaft angle includes:

[0016] determining a wide side and a narrow side of the camshaft based on a magnitude relationship between the target camshaft rotation angle and a rotation angle threshold;

[0017] If there are edges before and after the falling edge that meet the preset wide and narrow edge type conditions, the falling edge that meets the preset wide and narrow edge type conditions is determined as the target falling edge.

[0018] Optionally, determining a second resolver signal corresponding to a compression top dead center of a first cylinder among the plurality of cylinders based on the first resolver signal and a target tooth pitch includes:

[0019] determining a first parameter based on the target tooth pitch;

[0020] If a target difference between the first resolver signal and the first parameter is greater than or equal to zero, determining that the second resolver signal is the target difference;

[0021] If a target difference between the first resolver signal and the first parameter is less than zero, the second resolver signal is determined to be a sum of the target difference and a preset degree.

[0022] Optionally, determining a mapping relationship between a current resolver signal of the rotating shaft and a crankshaft angle of the crankshaft based on the second resolver signal includes:

[0023] defining a target crankshaft angle corresponding to the second resolver signal, and redefining the module containing the second resolver signal as the first module;

[0024] When the crankshaft rotates, the module to which the current resolver signal belongs is determined based on the redefined first module, and the current degree of the crankshaft angle is determined based on the current resolver signal, the module to which the current resolver signal belongs, the second resolver signal, and the target degree.

[0025] Optionally, determining a first duration of a power stroke of combustion of a target cylinder among the plurality of cylinders based on the mapping relationship includes:

[0026] determining a crankshaft angle range corresponding to a power stroke of combustion in the target cylinder;

[0027] The duration for the current resolver signal to change from the first signal to the second signal is recorded as the first duration; the first signal corresponds to the lower limit value of the crankshaft angle range, and the second signal corresponds to the upper limit value of the crankshaft angle range.

[0028] Optionally, determining whether the range extender has misfired based on the first duration includes:

[0029] Obtaining a second duration of a power stroke of a cylinder that burns before the target cylinder and a third duration of a power stroke of a cylinder that burns after the target cylinder;

[0030] If a first difference between the first duration and the second duration is positive, and a second difference between the first duration and the third duration is positive, taking the sum of the first difference and the second difference as a first reference duration of the power stroke of the combustion of the target cylinder;

[0031] Obtaining a second reference duration of a power stroke of a cylinder that burns before the target cylinder;

[0032] If a first reference difference between the first reference time and the second reference time is positive, obtaining a second reference difference of the power stroke of the last combustion of the target cylinder;

[0033] If a target difference between the first reference difference and the second reference difference is greater than a preset threshold, it is determined that the range extender is misfired.

[0034] In a second aspect, the present application further provides a range extender misfire diagnostic device, the range extender including an engine and a generator, the engine including a camshaft, a crankshaft, and a plurality of cylinders, the generator including a rotating shaft, the camshaft connected to the crankshaft, the plurality of cylinders connected to the crankshaft, and the rotating shaft connected to the crankshaft; the device including:

[0035] a first determining module, configured to determine a first resolver signal corresponding to a target falling edge of the camshaft based on a target resolver signal of the rotating shaft; the target resolver signal being a set of resolver signals corresponding to a rising edge and a falling edge of the camshaft;

[0036] a second determination module, configured to determine a second resolver signal corresponding to a compression top dead center of a first cylinder among the plurality of cylinders based on the first resolver signal and a target tooth pitch; wherein a fixed tooth pitch relationship exists between the target falling edge and the compression top dead center of the first cylinder, and the target tooth pitch is a distance between the target falling edge and the compression top dead center of the first cylinder;

[0037] a third determining module, configured to determine a mapping relationship between a current resolver signal of the rotating shaft and a crankshaft angle of the crankshaft based on the second resolver signal;

[0038] a fourth determining module, configured to determine, based on the mapping relationship, a first duration of a power stroke of combustion of a target cylinder among the plurality of cylinders; the target cylinder being a cylinder currently burning among the plurality of cylinders;

[0039] A fifth determining module is configured to determine whether the range extender has misfired based on the first duration.

[0040] In a third aspect, the present application further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in the first aspect when executing the computer program.

[0041] In a fourth aspect, the present application further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which implements the method described in the first aspect when executed by a processor.

[0042] In a fifth aspect, the present application further provides a computer program product, comprising a computer program, which implements the method described in the first aspect when executed by a processor.

[0043] The range extender misfire diagnosis method, device, equipment and medium provided in the present application determine the first rotary signal corresponding to the target falling edge of the camshaft through the target rotary signal of the rotating shaft, determine the second rotary signal corresponding to the compression top dead center of the first cylinder through the first rotary signal, determine the mapping relationship between the current rotary signal and the crankshaft angle through the second rotary signal, and determine the first duration of the power stroke of the combustion of the target cylinder through the mapping relationship, so as to calculate the crankshaft angle by replacing the crankshaft position sensor signal with the rotary signal, and then calculate the first duration. The engine crankshaft position sensor can be eliminated to achieve cost reduction, and the accuracy of the first duration calculation can be improved, thereby improving the range extender misfire diagnosis accuracy. In the case of high misfire rate, the resonance effect caused by mechanical structures such as traditional systems can be avoided to cause missed misfire reports, thereby solving the problem of missed misfire identification under high misfire rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the present application or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0045] Figure 1 This is a schematic diagram of the crankshaft speed when a cylinder misfires, as provided in the background art of this application;

[0046] Figure 2 This is a schematic diagram of a missed fire identification situation provided by the background technology of this application;

[0047] Figure 3 1 is a flow chart of a range extender misfire diagnosis method provided in an embodiment of the present application;

[0048] Figure 4 Schematic diagram of the corresponding relationship between the camshaft signal and the resolver signal provided in the embodiment of the present application;

[0049] Figure 5 This is a schematic diagram of the principle of determining the target falling edge based on preset wide and narrow edge type conditions provided by an embodiment of the present application;

[0050] Figure 6 Schematic diagram of the positional relationship between the target falling edge and the compression upper limb point of the first cylinder provided in an embodiment of the present application;

[0051] Figure 7 Schematic diagram of the mapping relationship between the current resolver signal and the crankshaft angle provided in an embodiment of the present application;

[0052] Figure 8 This is a flowchart of the first benchmark duration calculation provided by an embodiment of the present application;

[0053] Figure 9 1 is a flow chart of calculating the first benchmark difference provided in an embodiment of the present application;

[0054] Figure 10 Schematic diagram of the target difference calculation process provided in the embodiment of the present application;

[0055] Figure 11 Schematic diagram of the structure of the range extender misfire diagnosis device provided in an embodiment of the present application;

[0056] Figure 12 It is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0057] The engine and generator each have their own "position sensor". The engine is generally equipped with a crankshaft position sensor, which can be used to calculate the rotation speed and position of the crankshaft with an accuracy of 360° / 60=6°; the generator is generally equipped with a rotary transformer, which can be used to calculate the angular velocity and rotation angle of the rotating shaft. Taking four pairs of poles as an example, the accuracy can be as high as 0.087°. The accuracy of the rotary transformer signal is 4 times that of the crankshaft position sensor equipped on traditional engines, and it has advantages in more complex calculation methods and higher precision applications. Based on this, the present application provides a method for diagnosing range extender misfire based on the generator rotary transformer signal (i.e., resolver signal).

[0058] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0059] An embodiment of the present application provides a range extender misfire diagnosis method, the execution subject of which may be an electronic device, for example, a controller. The following description will be made using the controller as an example in which the execution subject of the method is a controller. Figure 3This is a flow chart of a range extender misfire diagnosis method provided by an embodiment of the present application. The range extender includes an engine and a generator. The engine includes a camshaft, a crankshaft, and a plurality of cylinders. The generator includes a rotating shaft. The camshaft is connected to the crankshaft. The plurality of cylinders are connected to the crankshaft. The rotating shaft is connected to the crankshaft. Figure 3 , the method may include:

[0060] Step 310: Determine a first resolver signal corresponding to a target falling edge of the camshaft based on a target resolver signal of the rotating shaft; the target resolver signal is a set of resolver signals corresponding to a rising edge and a falling edge of the camshaft;

[0061] Step 320: Determine a second resolver signal corresponding to the compression top dead center of a first cylinder among the multiple cylinders based on the first resolver signal and the target tooth pitch; there is a fixed tooth pitch relationship between the target falling edge and the compression top dead center of the first cylinder, and the target tooth pitch is the distance between the target falling edge and the compression top dead center of the first cylinder;

[0062] Step 330: Determine a mapping relationship between the current resolver signal of the rotating shaft and the crankshaft angle of the crankshaft based on the second resolver signal;

[0063] Step 340: Determine a first duration of a power stroke of combustion of a target cylinder among the multiple cylinders based on the mapping relationship; the target cylinder is a cylinder currently burning among the multiple cylinders;

[0064] Step 350: Determine whether the range extender has misfired based on the first duration.

[0065] This application is introduced based on the range extender configuration. The engine and generator speed ratio can be 1:1, and the resolver can be a four-pole signal. The camshaft signal can be a 4-tooth signal with two large and two small teeth. The 4 360° signals of the four-pole resolver correspond to one rotation of the crankshaft. Therefore, the camshaft rotates 1 circle, the crankshaft rotates 2 circles, and the resolver signal undergoes 8 0-360° jumps. The target falling edge of the camshaft is defined as the falling edge closest to the compression top dead center of the first cylinder (i.e., cylinder 1), which is k teeth away from the compression top dead center of cylinder 1 (crankshaft tooth 1 is 6°, and the actual distance between the two is 6k°). This relationship is determined by the hardware. If each 360° of the resolver signal is defined as a block, the camshaft rotates 1 circle (crankshaft rotates 2 circles), and the resolver signal corresponds to 8 modules.

[0066] The basic logic of the present application is as follows: in step 310, the target falling edge of the camshaft is identified by the target resolver signal, thereby determining a first resolver signal corresponding to the target falling edge; in step 320, the compression top dead center position of the first cylinder (i.e., cylinder 1) having a fixed tooth pitch relationship with the target falling edge is found, thereby finding a second resolver signal corresponding to the compression top dead center position of cylinder 1; in step 330, the mapping relationship between the current resolver signal and the crankshaft angle of the crankshaft is determined by the second resolver signal; in step 340, the duration of the cylinder power stroke is generally calculated by the change in the crankshaft angle; after determining the mapping relationship between the current resolver signal and the crankshaft angle, the duration of the cylinder power stroke can be calculated by the change in the current resolver signal, thereby obtaining a first duration of the power stroke of the target cylinder currently being burned; in step 350, whether the range extender has misfired can be determined by the first duration.

[0067] The range extender misfire diagnosis method provided in the embodiment of the present application determines the first resolvent signal corresponding to the target falling edge of the camshaft through the target resolvent signal of the rotating shaft, determines the second resolvent signal corresponding to the compression top dead center of the first cylinder through the first resolvent signal, determines the mapping relationship between the current resolvent signal and the crankshaft angle through the second resolvent signal, and determines the first duration of the power stroke of the combustion of the target cylinder through the mapping relationship, thereby calculating the crankshaft angle by replacing the crankshaft position sensor signal with the resolvent signal, and then calculating the first duration. The engine crankshaft position sensor can be eliminated to achieve cost reduction, and the accuracy of the first duration calculation can be improved, thereby improving the range extender misfire diagnosis accuracy. In the case of high misfire rate, the misfire missed report caused by the resonance effect brought by mechanical structures such as traditional systems can be avoided, thereby solving the problem of misfire missed identification under high misfire rate.

[0068] In some embodiments, based on the target rotary signal of the rotating shaft, the first rotary signal corresponding to the target falling edge of the camshaft is determined, including: when the rising edge or falling edge of the camshaft is identified for the first time, recording the rotary signal at this time as the first target signal, and defining the module where the first target signal is located as the first module; determining multiple target signals in the target rotary signal corresponding to the rising edge or falling edge that appears when the camshaft rotates one circle starting from the first target signal, and determining the module where each target signal in the multiple target signals is located based on the first module; determining the target camshaft angle based on the multiple target signals and the module where each target signal is located; the target camshaft angle is the camshaft angle corresponding to the wide side of the camshaft and the camshaft angle corresponding to the narrow side; based on the target camshaft angle, determining the target falling edge, and using the rotary signal corresponding to the target falling edge as the first rotary signal.

[0069] The controller can identify a square wave signal with high and low levels formed by four teeth, two large and two small, on the camshaft target wheel through the camshaft position sensor, which is called the camshaft signal. The controller can continuously identify the camshaft signal and its rising and falling edges. There are 4 falling edges in the camshaft signal when the camshaft rotates one circle, and the fixed interval between each falling edge is 180° crankshaft rotation angle. During the process of the camshaft rotating one circle, by identifying the rising and falling edges, 8 rotation angle intervals corresponding to high and low levels can be obtained. Since the wide tooth pitch and narrow tooth pitch of the camshaft target wheel are fixed, there are only two types of these rotation angle intervals corresponding to high and low levels. The longer one is called the "wide side", and the shorter one is called the "narrow side".

[0070] Let the camshaft signal be U (0V ≤ U ≤ 5V), and the high and low level recognition voltage be U0 (commonly used U0 is 2.5V), then there is:

[0071] When U i , i , i+1 , 1， , , i ,

[0075] > U0 and U n-1 < U0, a rising edge is recognized;

[0072] When U n < U0 and U n-1 > U0, a falling edge is recognized.

[0073] Figure 4 It is a schematic diagram of the correspondence between the camshaft signal and the resolver signal provided by the embodiment of the present application. As Figure 4 shown, after the controller first recognizes a rising edge or a falling edge, record the resolver signal at this time as the first target signal θ1, and temporarily define the module where this resolver signal is located as the first module. After that, each time the resolver signal changes from 360° to 0°, the module number +1. When the module > 8, reset the module number to 1.

[0074] Since there are 8 rising edges + falling edges when the camshaft rotates one circle, and the module jumps from 1 to 8, the resolver signal will change 8 times from 0 to 360°. Therefore, multiple target signals θ1 to θ8 in the target resolver signal corresponding to the rising and falling edges that appear in the direction of rotating one circle along the camshaft starting from the first target signal can be obtained in sequence, and the serial numbers N1 to N8 of the modules where each target signal is located. Among them, the first target signal belongs to one of the multiple target signals, and the first target signal is the first one obtained among the multiple target signals. At the same time, for the convenience of calculation, record θ9 = θ 1， N9 = N1. Then, among the camshaft high and low level signals obtained when the camshaft rotates one circle, the target camshaft rotation angle ψ i (0 to 720°) corresponding to the i-th wide side / narrow side (i = 1 to 8) is: ?

[0075] When N i = 8 and N i+1 = 1: ψ i=90+(θ i+1 -θ i ) / 4;

[0076] In other cases: ψ i =(N i -N1)x90+(θ i -θ1) / 4.

[0077] Furthermore, the target falling edge can be determined according to the size of the target camshaft rotation angle, and the resolver signal corresponding to the target falling edge is used as the first resolver signal.

[0078] The range extender misfire diagnosis method provided in an embodiment of the present application determines a first resolvent signal corresponding to a target falling edge of a camshaft through a target resolvent signal of a rotating shaft, determines a second resolvent signal corresponding to a compression top dead center of a first cylinder through the first resolvent signal, determines a mapping relationship between a current resolvent signal and a crankshaft angle through the second resolvent signal, and determines a first duration of a power stroke of combustion in a target cylinder through the mapping relationship, thereby calculating the crankshaft angle and further calculating the first duration by using the resolvent signal instead of a crankshaft position sensor signal. This can improve the accuracy of the first duration calculation, thereby improving the accuracy of the range extender misfire diagnosis.

[0079] In some embodiments, a target falling edge is determined based on a target camshaft angle, including: determining the wide side and narrow side of the camshaft based on a size relationship between the target camshaft angle and a rotation angle threshold; if there are edges before and after the falling edge that meet preset wide and narrow edge type conditions, the falling edge that meets the preset wide and narrow edge type conditions is determined as the target falling edge.

[0080] Figure 5 This is a schematic diagram of the principle of determining the target falling edge based on the preset wide and narrow edge type conditions provided by the embodiment of the present application. Figure 5 As shown, ψ0 is the angle threshold for judging the wide side and narrow side. This value can be determined by hardware design. The average of the camshaft angles corresponding to the wide side and narrow side can be taken. The common value is 90°. i When >ψ0, this edge is identified as a "wide edge"; otherwise, it is a "short edge".

[0081] Every falling edge of the camshaft is special, and the "wide side" and "narrow side" before and after the falling edge are different: the first falling edge: wide side -> wide side; the second falling edge: narrow side -> wide side; the third falling edge: narrow side -> narrow side; the fourth falling edge: wide side -> narrow side.

[0082] By identifying the "wide edge" and "narrow edge" types before and after each falling edge, the controller can find a special falling edge that meets the preset wide and narrow edge type conditions as the target falling edge, and record the first resolver signal corresponding to the target falling edge as θde (de means falling edge, descending edge).

[0083] The range extender misfire diagnosis method provided in an embodiment of the present application determines a first resolvent signal corresponding to a target falling edge of a camshaft through a target resolvent signal of a rotating shaft, determines a second resolvent signal corresponding to a compression top dead center of a first cylinder through the first resolvent signal, determines a mapping relationship between a current resolvent signal and a crankshaft angle through the second resolvent signal, and determines a first duration of a power stroke of combustion in a target cylinder through the mapping relationship, thereby calculating the crankshaft angle and further calculating the first duration by using the resolvent signal instead of a crankshaft position sensor signal. This can improve the accuracy of the first duration calculation, thereby improving the accuracy of the range extender misfire diagnosis.

[0084] In some embodiments, based on the first resolver signal and the target tooth pitch, a second resolver signal corresponding to the compression top dead center of a first cylinder among a plurality of cylinders is determined, including: determining a first parameter based on the target tooth pitch; if the target difference between the first resolver signal and the first parameter is greater than or equal to zero, determining the second resolver signal to be the target difference; if the target difference between the first resolver signal and the first parameter is less than zero, determining the second resolver signal to be the sum of the target difference and a preset degree.

[0085] Figure 6 Schematic diagram of the positional relationship between the target falling edge and the compression upper limb point of the first cylinder provided in the embodiment of the present application. Figure 6 As shown, there is a fixed tooth pitch relationship between the target falling edge and the compression top dead center of the first cylinder, or a fixed crankshaft rotation angle relationship. Assuming that the distance between the compression top dead center of the first cylinder and the target falling edge of the camshaft is k teeth, the second resolver signal θ corresponding to the compression top dead center of the first cylinder is init There are two cases:

[0086] When θ de -(6k×4)≥0, then θ init =θ de -(6k×4);

[0087] When θ de -(6k×4)<0, then θ init =θ de -(6k×4)+360.

[0088] Among them, 6k×4 is the first parameter, and 360 is the preset degree.

[0089] The range extender misfire diagnosis method provided in an embodiment of the present application determines a first resolvent signal corresponding to a target falling edge of a camshaft through a target resolvent signal of a rotating shaft, determines a second resolvent signal corresponding to a compression top dead center of a first cylinder through the first resolvent signal, determines a mapping relationship between a current resolvent signal and a crankshaft angle through the second resolvent signal, and determines a first duration of a power stroke of combustion in a target cylinder through the mapping relationship, thereby calculating the crankshaft angle and further calculating the first duration by using the resolvent signal instead of a crankshaft position sensor signal. This can improve the accuracy of the first duration calculation, thereby improving the accuracy of the range extender misfire diagnosis.

[0090] In some embodiments, based on the second resolver signal, a mapping relationship between a current resolver signal of a rotating shaft and a crankshaft angle of a crankshaft is determined, including: defining a target degree of the crankshaft angle corresponding to the second resolver signal, and redefining the module where the second resolver signal is located as the first module; when the crankshaft rotates, based on the redefined first module, determining the module to which the current resolver signal belongs, and determining the current degree of the crankshaft angle based on the current resolver signal, the module to which the current resolver signal belongs, the second resolver signal, and the target degree.

[0091] Figure 7 Schematic diagram of the mapping relationship between the current resolver signal and the crankshaft angle provided in the embodiment of the present application. Figure 7 As shown, the second resolver signal θ init The corresponding module is redefined as the first module, and subsequent modules are numbered 2 to 8. Modules beyond number 8 are reset to number 1, and the counting continues in this order. Two crankshaft revolutions span 0 to 720°, and the resolver signal undergoes four power strokes (1-3-4-2). Therefore, the resolver signal can be used to calculate the position and rotation angle of the crankshaft during rotation.

[0092] θ init The position of is defined as the target degree of the crankshaft angle 0°. When the crankshaft rotates to any angle ψ (0≤ψ<720°), the rotation angle is θ (0≤θ<360°), which is located in the jth module (1≤j≤8, j is an integer). The current degree of the crankshaft angle ψ is calculated as follows:

[0093] If j = 1, and θ < θ init When: ψ=720+(θ-θ init ) / 4;

[0094] In other cases: ψ=90×(j-1)+(θ-θ init ) / 4.

[0095] The range extender misfire diagnosis method provided in an embodiment of the present application determines a first resolvent signal corresponding to a target falling edge of a camshaft through a target resolvent signal of a rotating shaft, determines a second resolvent signal corresponding to a compression top dead center of a first cylinder through the first resolvent signal, determines a mapping relationship between a current resolvent signal and a crankshaft angle through the second resolvent signal, and determines a first duration of a power stroke of combustion in a target cylinder through the mapping relationship, thereby calculating the crankshaft angle and further calculating the first duration by using the resolvent signal instead of a crankshaft position sensor signal. This can improve the accuracy of the first duration calculation, thereby improving the accuracy of the range extender misfire diagnosis.

[0096] In some embodiments, based on a mapping relationship, a first duration of a power stroke of combustion in a target cylinder among a plurality of cylinders is determined, including: determining a crankshaft angle range corresponding to the power stroke of combustion in the target cylinder; recording a duration for the current rotary signal to change from a first signal to a second signal as the first duration; the first signal corresponds to a lower limit value of the crankshaft angle range, and the second signal corresponds to an upper limit value of the crankshaft angle range.

[0097] If the combustion order of multiple cylinders in this application is 1-3-4-2. The crankshaft angle range corresponding to the power stroke of cylinder 1 combustion is 0°-180°, the crankshaft angle range corresponding to the power stroke of cylinder 3 combustion is 180°-360°, the crankshaft angle range corresponding to the power stroke of cylinder 4 combustion is 360°-540°, and the crankshaft angle range corresponding to the power stroke of cylinder 2 combustion is 540°-720°. When the crankshaft angle ψ corresponding to the current resolver signal is 0°, the timer starts timing. When the crankshaft angle ψ corresponding to the current resolver signal is 180°, the timer ends and the time is recorded as t1, which is the duration of the power stroke of the combustion of cylinder 1. When the crankshaft angle ψ corresponding to the current resolver signal is 180°, the timer starts timing. When the crankshaft angle ψ corresponding to the current resolver signal is 360°, the timer ends and the time is recorded as t2, which is the duration of the power stroke of the combustion of cylinder 3. °, the timer starts timing. When the crankshaft angle ψ corresponding to the current resolver signal is 540°, the timer ends and the time is recorded as t3, which is the duration corresponding to the power stroke of the combustion of the 4th cylinder; when the crankshaft angle ψ corresponding to the current resolver signal is 540°, the timer starts timing. When the crankshaft angle ψ corresponding to the current resolver signal is 720°, the timer ends and the time is recorded as t4, which is the duration corresponding to the power stroke of the combustion of the 2nd cylinder. The duration corresponding to the power stroke of the combustion of the cylinder currently burning is used as the first duration.

[0098] Based on the descriptions of the above embodiments, even in the absence of a crankshaft position sensor signal, the crankshaft angle relative to the compression top dead center of cylinder 1 when the crankshaft rotates to any position can be obtained through the camshaft position signal and the rotational signal. Therefore, the duration of the power stroke corresponding to the combustion of each cylinder can also be obtained, that is, the time Δt that the crankshaft takes to run from the compression top dead center to the compression bottom dead center of the nth cylinder.

[0099] The range extender misfire diagnosis method provided in an embodiment of the present application determines a first resolvent signal corresponding to a target falling edge of a camshaft through a target resolvent signal of a rotating shaft, determines a second resolvent signal corresponding to a compression top dead center of a first cylinder through the first resolvent signal, determines a mapping relationship between a current resolvent signal and a crankshaft angle through the second resolvent signal, and determines a first duration of a power stroke of combustion in a target cylinder through the mapping relationship, thereby calculating the crankshaft angle and further calculating the first duration by using the resolvent signal instead of a crankshaft position sensor signal. This can improve the accuracy of the first duration calculation, thereby improving the accuracy of the range extender misfire diagnosis.

[0100] In some embodiments, determining whether the range extender has misfired based on the first duration includes: obtaining a second duration of a power stroke of the cylinder that burns before the target cylinder, and a third duration of a power stroke of the cylinder that burns after the target cylinder; if a first difference between the first duration and the second duration is positive, and a second difference between the first duration and the third duration is positive, taking the sum of the first difference and the second difference as a first reference duration of the power stroke of the target cylinder; obtaining a second reference duration of the power stroke of the cylinder that burns before the target cylinder; if the first reference difference between the first reference duration and the second reference duration is positive, obtaining a second reference difference of the power stroke of the last combustion of the target cylinder; if the difference between the first reference difference and the second reference difference is greater than a preset threshold, determining that the range extender has misfired.

[0101] In the misfire algorithm, higher-order dynamic information can be obtained by taking multiple derivatives of Δt to capture more accurate speed change trends. For example, taking a single derivative of Δt can obtain the time period inversely proportional to the angular acceleration: ΔΔt = d(Δt) / dt = -Δt. 2 α (α is angular acceleration), etc. These methods may help solve the problem of missed misfire diagnosis, but they will increase computational complexity and require higher signal accuracy and additional filtering. Therefore, this application proposes a new method for determining range extender misfire based on Δt.

[0102] Based on the description of the above embodiments, the second duration and the third duration may be calculated in a similar manner to the calculation of the first duration.

[0103] Figure 8This is a schematic diagram of the first benchmark duration calculation process provided in an embodiment of the present application. The current combustion, i.e., the target cylinder combustion, is the nth combustion; the cylinder combustion preceding the target cylinder is the n-1th combustion; and the cylinder combustion following the target cylinder is the n+1th combustion. Tn is the first benchmark duration.

[0104] Figure 9 : is a flow chart of calculating the first reference difference provided by an embodiment of the present application, wherein Tn-1 is the second reference duration, and ΔTn is the first reference difference.

[0105] Figure 10 : is a flow chart of target difference calculation provided by an embodiment of the present application, wherein the last combustion of the target cylinder is the n-4th combustion, ΔTn-4 is the second reference difference, ΔΔTn is the target difference, and Tthrsh is the preset threshold.

[0106] Under other conditions, other methods are needed to determine the misfire condition of the range extender.

[0107] The range extender misfire diagnosis method provided in the embodiment of the present application determines whether the range extender has misfired by continuously performing subtraction to obtain a first reference time length, a first reference difference value, a target difference value, etc. The calculation effect of multiple derivations of the first time length can be achieved through a relatively simple calculation method, thereby improving the diagnostic accuracy of the range extender misfire.

[0108] The range extender misfire diagnostic device provided in the present application is described below. The range extender misfire diagnostic device described below and the range extender misfire diagnostic method described above can be referenced to each other.

[0109] Figure 11 : This is a schematic diagram of the structure of the range extender misfire diagnosis device provided by an embodiment of the present application. The range extender includes an engine and a generator, the engine includes a camshaft, a crankshaft and a plurality of cylinders, the generator includes a rotating shaft, the camshaft is connected to the crankshaft, the plurality of cylinders are connected to the crankshaft, and the rotating shaft is connected to the crankshaft. Figure 11 The range extender misfire diagnosis device provided in the embodiment of the present application may include:

[0110] A first determining module 1110 is configured to determine a first resolver signal corresponding to a target falling edge of the camshaft based on a target resolver signal of the rotating shaft; the target resolver signal is a set of resolver signals corresponding to a rising edge and a falling edge of the camshaft;

[0111] a second determination module 1120 configured to determine a second resolver signal corresponding to a compression top dead center of a first cylinder among the plurality of cylinders based on the first resolver signal and a target tooth pitch; wherein the target falling edge and the compression top dead center of the first cylinder have a fixed tooth pitch relationship, and the target tooth pitch is the distance between the target falling edge and the compression top dead center of the first cylinder;

[0112] a third determining module 1130, configured to determine a mapping relationship between a current resolver signal of the rotating shaft and a crankshaft angle of the crankshaft based on the second resolver signal;

[0113] a fourth determining module 1140 configured to determine, based on the mapping relationship, a first duration of a power stroke of combustion of a target cylinder among the plurality of cylinders; the target cylinder being a cylinder currently burning among the plurality of cylinders;

[0114] The fifth determining module 1150 is configured to determine whether the range extender has misfired based on the first duration.

[0115] The range extender misfire diagnosis device provided in the embodiment of the present application determines a first resolvent signal corresponding to a target falling edge of the camshaft through a target resolvent signal of a rotating shaft, determines a second resolvent signal corresponding to a compression top dead center of the first cylinder through the first resolvent signal, determines a mapping relationship between the current resolvent signal and the crankshaft angle through the second resolvent signal, and determines a first duration of a power stroke of combustion in the target cylinder through the mapping relationship, thereby calculating the crankshaft angle and further calculating the first duration by replacing the crankshaft position sensor signal with the resolvent signal. This eliminates the need for an engine crankshaft position sensor, thereby achieving cost reduction, and improving the accuracy of the first duration calculation, thereby improving the range extender misfire diagnosis accuracy. In the case of a high misfire rate, this device can avoid missed misfire reports due to resonance effects caused by mechanical structures such as traditional systems, thereby solving the problem of missed misfire identification under high misfire rates.

[0116] In some embodiments, the first determining module is configured to:

[0117] When a rising edge or a falling edge of the camshaft is identified for the first time, the resolver signal at this time is recorded as a first target signal, and a module where the first target signal is located is defined as a first module;

[0118] determining a plurality of target signals in the target resolver signal corresponding to a rising edge or a falling edge appearing when the camshaft rotates one circle starting from the first target signal, and determining a module where each target signal in the plurality of target signals is located based on the first module;

[0119] Determining a target camshaft angle based on the multiple target signals and the module where each target signal is located; the target camshaft angle is the camshaft angle corresponding to the wide side and the camshaft angle corresponding to the narrow side of the camshaft;

[0120] Based on the target camshaft rotation angle, the target falling edge is determined, and a resolver signal corresponding to the target falling edge is used as the first resolver signal.

[0121] In some embodiments, the first determining module is configured to:

[0122] determining a wide side and a narrow side of the camshaft based on a magnitude relationship between the target camshaft rotation angle and a rotation angle threshold;

[0123] If there are edges before and after the falling edge that meet the preset wide and narrow edge type conditions, the falling edge that meets the preset wide and narrow edge type conditions is determined as the target falling edge.

[0124] In some embodiments, the second determining module is configured to:

[0125] determining a first parameter based on the target tooth pitch;

[0126] If a target difference between the first resolver signal and the first parameter is greater than or equal to zero, determining that the second resolver signal is the target difference;

[0127] If a target difference between the first resolver signal and the first parameter is less than zero, the second resolver signal is determined to be a sum of the target difference and a preset degree.

[0128] In some embodiments, the third determining module is configured to:

[0129] defining a target crankshaft angle corresponding to the second resolver signal, and redefining the module containing the second resolver signal as the first module;

[0130] When the crankshaft rotates, the module to which the current resolver signal belongs is determined based on the redefined first module, and the current degree of the crankshaft angle is determined based on the current resolver signal, the module to which the current resolver signal belongs, the second resolver signal, and the target degree.

[0131] In some embodiments, the fourth determining module is configured to:

[0132] determining a crankshaft angle range corresponding to a power stroke of combustion in the target cylinder;

[0133] The duration for the current resolver signal to change from the first signal to the second signal is recorded as the first duration; the first signal corresponds to the lower limit value of the crankshaft angle range, and the second signal corresponds to the upper limit value of the crankshaft angle range.

[0134] In some embodiments, the fifth determining module is configured to:

[0135] Obtaining a second duration of a power stroke of a cylinder that burns before the target cylinder and a third duration of a power stroke of a cylinder that burns after the target cylinder;

[0136] If a first difference between the first duration and the second duration is positive, and a second difference between the first duration and the third duration is positive, taking the sum of the first difference and the second difference as a first reference duration of the power stroke of the combustion of the target cylinder;

[0137] Obtaining a second reference duration of a power stroke of a cylinder that burns before the target cylinder;

[0138] If a first reference difference between the first reference time and the second reference time is positive, obtaining a second reference difference of the power stroke of the last combustion of the target cylinder;

[0139] If a target difference between the first reference difference and the second reference difference is greater than a preset threshold, it is determined that the range extender is misfired.

[0140] Specifically, the range extender misfire diagnostic device provided in the embodiment of the present application can implement all the method steps implemented in the method embodiment in which the execution subject is the controller, and can achieve the same technical effects. The parts and beneficial effects of this embodiment that are the same as those of the method embodiment will not be described in detail here.

[0141] Figure 12 Schematic diagram of the structure of the electronic device provided in the embodiment of the present application. Figure 12 As shown, the electronic device may include: a processor 1210, a communication interface 1220, a memory 1230, and a communication bus 1240, wherein the processor 1210, the communication interface 1220, and the memory 1230 communicate with each other via the communication bus 1240. The processor 1210 may call the logic instructions in the memory 1230 to execute the range extender misfire diagnosis method, for example, including:

[0142] Determining a first resolver signal corresponding to a target falling edge of the camshaft based on a target resolver signal of the rotating shaft; the target resolver signal is a set of resolver signals corresponding to a rising edge and a falling edge of the camshaft;

[0143] determining, based on the first resolver signal and a target tooth pitch, a second resolver signal corresponding to a compression top dead center of a first cylinder among the plurality of cylinders; wherein a fixed tooth pitch relationship exists between the target falling edge and the compression top dead center of the first cylinder, and the target tooth pitch is a distance between the target falling edge and the compression top dead center of the first cylinder;

[0144] determining, based on the second resolver signal, a mapping relationship between a current resolver signal of the rotating shaft and a crankshaft angle of the crankshaft;

[0145] Determining a first duration of a power stroke of combustion of a target cylinder among the plurality of cylinders based on the mapping relationship; the target cylinder is a cylinder currently burning among the plurality of cylinders;

[0146] Based on the first time period, it is determined whether the range extender misfires.

[0147] In addition, the logic instructions in the above-mentioned memory 1230 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0148] On the other hand, the present application also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the range extender misfire diagnosis method provided by the above methods are implemented, for example, including:

[0149] Determining a first resolver signal corresponding to a target falling edge of the camshaft based on a target resolver signal of the rotating shaft; the target resolver signal is a set of resolver signals corresponding to a rising edge and a falling edge of the camshaft;

[0150] determining, based on the first resolver signal and a target tooth pitch, a second resolver signal corresponding to a compression top dead center of a first cylinder among the plurality of cylinders; wherein a fixed tooth pitch relationship exists between the target falling edge and the compression top dead center of the first cylinder, and the target tooth pitch is a distance between the target falling edge and the compression top dead center of the first cylinder;

[0151] determining, based on the second resolver signal, a mapping relationship between a current resolver signal of the rotating shaft and a crankshaft angle of the crankshaft;

[0152] Determining a first duration of a power stroke of combustion of a target cylinder among the plurality of cylinders based on the mapping relationship; the target cylinder is a cylinder currently burning among the plurality of cylinders;

[0153] Based on the first time period, it is determined whether the range extender misfires.

[0154] In another aspect, the present application further provides a computer program product, comprising a computer program. The computer program may be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can perform the steps of the range extender misfire diagnosis method provided by the above methods, for example, including:

[0155] Determining a first resolver signal corresponding to a target falling edge of the camshaft based on a target resolver signal of the rotating shaft; the target resolver signal is a set of resolver signals corresponding to a rising edge and a falling edge of the camshaft;

[0156] determining, based on the first resolver signal and a target tooth pitch, a second resolver signal corresponding to a compression top dead center of a first cylinder among the plurality of cylinders; wherein a fixed tooth pitch relationship exists between the target falling edge and the compression top dead center of the first cylinder, and the target tooth pitch is a distance between the target falling edge and the compression top dead center of the first cylinder;

[0157] determining, based on the second resolver signal, a mapping relationship between a current resolver signal of the rotating shaft and a crankshaft angle of the crankshaft;

[0158] Determining a first duration of a power stroke of combustion of a target cylinder among the plurality of cylinders based on the mapping relationship; the target cylinder is a cylinder currently burning among the plurality of cylinders;

[0159] Based on the first time period, it is determined whether the range extender misfires.

[0160] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0161] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the existing technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0162] It should also be noted that in the embodiments of the present application, the terms "first," "second," etc. are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein. The objects distinguished by "first," "second," etc. are generally of the same type, and do not limit the number of objects. For example, the first object can be one or more.

[0163] In the embodiments of the present application, the term "and / or" describes the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0164] In the embodiments of the present application, "determine B based on A" means that the factor A must be considered when determining B. It is not limited to "B can be determined based on A alone", and should also include: "determine B based on A and C", "determine B based on A, C and E", "determine C based on A, and further determine B based on C", etc. It can also include taking A as a condition for determining B, for example, "when A meets the first condition, use the first method to determine B"; for example, "when A meets the second condition, determine B", etc.; for example, "when A meets the third condition, determine B based on the first parameter", etc. Of course, it can also be a condition that takes A as a factor in determining B, for example, "when A meets the first condition, use the first method to determine C, and further determine B based on C", etc.

[0165] In the embodiments of the present application, the term "plurality" refers to two or more than two, and other quantifiers are similar thereto.

[0166] In the embodiments of the present application, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0167] In the embodiments of this application, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of this application based on the specific circumstances.

[0168] In the embodiments of the present application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0169] In the embodiments of the present application, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In the embodiments of the present application, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0170] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A range extender misfire diagnosis method, characterized in that: The range extender includes an engine and a generator, the engine includes a camshaft, a crankshaft, and a plurality of cylinders, the generator includes a rotating shaft, the camshaft is connected to the crankshaft, the plurality of cylinders are connected to the crankshaft, and the rotating shaft is connected to the crankshaft; the method includes: Determining a first resolver signal corresponding to a target falling edge of the camshaft based on a target resolver signal of the rotating shaft; the target resolver signal is a set of resolver signals corresponding to a rising edge and a falling edge of the camshaft; determining, based on the first resolver signal and a target tooth pitch, a second resolver signal corresponding to a compression top dead center of a first cylinder among the plurality of cylinders; wherein a fixed tooth pitch relationship exists between the target falling edge and the compression top dead center of the first cylinder, and the target tooth pitch is a distance between the target falling edge and the compression top dead center of the first cylinder; determining, based on the second resolver signal, a mapping relationship between a current resolver signal of the rotating shaft and a crankshaft angle of the crankshaft; Determining a first duration of a power stroke of combustion of a target cylinder among the plurality of cylinders based on the mapping relationship; the target cylinder is a cylinder currently burning among the plurality of cylinders; Based on the first time period, it is determined whether the range extender misfires.

2. The range extender misfire diagnosis method according to claim 1, characterized in that: The determining, based on the target resolver signal of the rotating shaft, a first resolver signal corresponding to a target falling edge of the camshaft includes: When a rising edge or a falling edge of the camshaft is identified for the first time, the resolver signal at this time is recorded as a first target signal, and a module where the first target signal is located is defined as a first module; determining a plurality of target signals in the target resolver signal corresponding to a rising edge or a falling edge appearing when the camshaft rotates one circle starting from the first target signal, and determining a module where each target signal in the plurality of target signals is located based on the first module; Determining a target camshaft angle based on the multiple target signals and the module where each target signal is located; the target camshaft angle is the camshaft angle corresponding to the wide side and the camshaft angle corresponding to the narrow side of the camshaft; Based on the target camshaft rotation angle, the target falling edge is determined, and a resolver signal corresponding to the target falling edge is used as the first resolver signal.

3. The range extender misfire diagnosis method according to claim 2, characterized in that: The determining the target falling edge based on the target camshaft angle includes: determining a wide side and a narrow side of the camshaft based on a magnitude relationship between the target camshaft rotation angle and a rotation angle threshold; If there are edges before and after the falling edge that meet the preset wide and narrow edge type conditions, the falling edge that meets the preset wide and narrow edge type conditions is determined as the target falling edge.

4. The range extender misfire diagnosis method according to claim 1, characterized in that: The determining, based on the first resolver signal and the target tooth pitch, a second resolver signal corresponding to the compression top dead center of a first cylinder among the plurality of cylinders includes: determining a first parameter based on the target tooth pitch; If a target difference between the first resolver signal and the first parameter is greater than or equal to zero, determining that the second resolver signal is the target difference; If a target difference between the first resolver signal and the first parameter is less than zero, the second resolver signal is determined to be a sum of the target difference and a preset degree.

5. The range extender misfire diagnosis method according to claim 1, characterized in that: Determining a mapping relationship between a current resolver signal of the rotating shaft and a crankshaft angle of the crankshaft based on the second resolver signal includes: defining a target crankshaft angle corresponding to the second resolver signal, and redefining the module containing the second resolver signal as the first module; When the crankshaft rotates, the module to which the current resolver signal belongs is determined based on the redefined first module, and the current degree of the crankshaft angle is determined based on the current resolver signal, the module to which the current resolver signal belongs, the second resolver signal, and the target degree.

6. The range extender misfire diagnosis method according to claim 1, characterized in that: Determining a first duration of a power stroke of combustion of a target cylinder among the plurality of cylinders based on the mapping relationship includes: determining a crankshaft angle range corresponding to a power stroke of combustion in the target cylinder; The duration for the current resolver signal to change from the first signal to the second signal is recorded as the first duration; the first signal corresponds to the lower limit value of the crankshaft angle range, and the second signal corresponds to the upper limit value of the crankshaft angle range.

7. The range extender misfire diagnosis method according to claim 1, characterized in that: The determining whether the range extender has misfired based on the first time period includes: Obtaining a second duration of a power stroke of a cylinder that burns before the target cylinder and a third duration of a power stroke of a cylinder that burns after the target cylinder; If a first difference between the first duration and the second duration is positive, and a second difference between the first duration and the third duration is positive, taking the sum of the first difference and the second difference as a first reference duration of the power stroke of the combustion of the target cylinder; Obtaining a second reference duration of a power stroke of a cylinder that burns before the target cylinder; If a first reference difference between the first reference time and the second reference time is positive, obtaining a second reference difference of the power stroke of the last combustion of the target cylinder; If a target difference between the first reference difference and the second reference difference is greater than a preset threshold, it is determined that the range extender is misfired.

8. A range extender misfire diagnostic device, characterized in that: The range extender includes an engine and a generator, wherein the engine includes a camshaft, a crankshaft, and a plurality of cylinders, the generator includes a rotating shaft, the camshaft is connected to the crankshaft, the plurality of cylinders are connected to the crankshaft, and the rotating shaft is connected to the crankshaft; the device includes: a first determining module, configured to determine a first resolver signal corresponding to a target falling edge of the camshaft based on a target resolver signal of the rotating shaft; the target resolver signal being a set of resolver signals corresponding to a rising edge and a falling edge of the camshaft; a second determination module, configured to determine a second resolver signal corresponding to a compression top dead center of a first cylinder among the plurality of cylinders based on the first resolver signal and a target tooth pitch; wherein a fixed tooth pitch relationship exists between the target falling edge and the compression top dead center of the first cylinder, and the target tooth pitch is a distance between the target falling edge and the compression top dead center of the first cylinder; a third determining module, configured to determine a mapping relationship between a current resolver signal of the rotating shaft and a crankshaft angle of the crankshaft based on the second resolver signal; a fourth determining module, configured to determine, based on the mapping relationship, a first duration of a power stroke of combustion of a target cylinder among the plurality of cylinders; the target cylinder being a cylinder currently burning among the plurality of cylinders; A fifth determining module is configured to determine whether the range extender has misfired based on the first duration.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the range extender misfire diagnosis method according to any one of claims 1 to 7 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the range extender misfire diagnosis method according to any one of claims 1 to 7 is implemented.

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