Engine misfire diagnosis method, device and equipment, medium and vehicle

Abstract

The invention discloses an engine misfire diagnosis method, device and equipment, a medium and a vehicle, and the method comprises the steps: when a range extender is in a normal power generation working condition, carrying out the statistics of a misfire counting value of an engine, and recording the misfire counting once when the operation state of the engine reaches a preset misfire detection state; when the misfire counting value is larger than a preset counting threshold value, the actual generated power and the required generated power of a generator are obtained; and according to the power error between the actual generated power and the required generated power in the sliding window, whether the engine has a misfire fault or not is determined, so that the accuracy and reliability of engine misfire diagnosis can be effectively improved, the situations of false alarm and missing alarm are reduced, and the reliability of engine misfire diagnosis is improved. Therefore, the running state monitoring and fault diagnosis capabilities of the engine are optimized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engine detection, in particular to an engine misfire diagnosis method, device, equipment, medium and vehicle. BACKGROUND

[0002] Engine misfire refers to that during the operation of the engine, the combustion process of one or more cylinders fails to proceed normally, resulting in that the cylinder fails to produce the expected power output. Engine misfire not only affects the power performance and fuel economy of the vehicle, but also may cause engine damage or even safety accidents. Therefore, accurate and timely diagnosis of engine misfire is crucial to ensure the safety of vehicle operation.

[0003] The traditional engine misfire diagnosis method mainly sets a crank angle acceleration threshold based on the engine speed and torque, and judges whether misfire occurs by detecting the crank angle acceleration in each combustion process. When the actual crank angle acceleration exceeds the set acceleration threshold, the misfire count is incremented by 1, and when the misfire count is greater than a certain threshold within a set period, misfire is determined. However, this method has many problems when applied to the range extender system.

[0004] During the operation of the engine, its output torque will be affected by the combustion process and will fluctuate slightly. In the range extender system, the generator needs to maintain a stable speed. When the engine torque changes slightly, the speed of the generator will be adjusted accordingly in order to maintain the stable speed of the generator. This adjustment will cause the crank angle acceleration to repeatedly exceed the corresponding acceleration threshold, causing the misfire count to repeatedly increase, resulting in that the misfire count reaches the corresponding count threshold when the engine is not truly misfiring, i.e. misfire is misjudged.

[0005] It can be seen that the existing engine misfire diagnosis method cannot meet the high precision and high reliability requirements of vehicle engine misfire diagnosis. Therefore, how to improve the accuracy and reliability of engine misfire diagnosis is a technical problem to be solved. SUMMARY

[0006] The present application provides an engine misfire diagnosis method, device, equipment, medium and vehicle, which can solve the technical problem of misjudgment of engine misfire diagnosis in the prior art, affecting the accuracy of diagnosis.

[0007] In a first aspect, an engine misfire diagnosis method is provided, which comprises: When the range extender is in a normal power generation condition, the misfire count value of the engine is counted, wherein the misfire count is recorded once every time the engine operating state reaches a preset misfire detection state; When the misfire count value is greater than a preset count threshold, the actual power generation power and the required power generation power of the generator are obtained; Based on the power error between the actual power generation and the required power generation within the set sliding window, it is determined whether the engine has a misfire fault.

[0008] In conjunction with the first aspect, in one embodiment, determining whether the engine has a misfire fault based on the power error between the actual power generation and the required power generation within a set sliding window includes: A first sliding window is set on the actual power generation, and the actual power generation is filtered by the first sliding window. After the sliding window filtering, the maximum value and minimum value of the actual power generation within the first sliding window are obtained. A second sliding window corresponding to the first sliding window is set on the demand power generation, and the demand power generation in the second sliding window is filtered by average value to obtain the corresponding average demand power generation. Based on the errors between the maximum and minimum actual power generation values ​​and the average required power generation value, it is determined whether the engine has a misfire fault.

[0009] In conjunction with the first aspect, in one embodiment, determining whether the engine has a misfire fault based on the errors between the maximum and minimum actual power generation values ​​and the average required power generation value, respectively, includes: Calculate the absolute value of the first difference between the maximum actual power generation and the average demanded power generation; Calculate the absolute value of the second difference between the minimum actual power generation and the average demanded power generation; If the absolute value of the first difference or the absolute value of the second difference is greater than a preset difference threshold, then it is determined that the engine has a misfire fault.

[0010] In conjunction with the first aspect, in one embodiment, setting the first sliding window on the actual power generation includes: Calculate the ignition cycle of the engine based on the engine speed and the number of cylinders. Multiply the ignition cycle period by the cycle factor to obtain the duration of the first sliding window; Wherein, the period multiple is an integer.

[0011] In conjunction with the first aspect, in one embodiment, before multiplying the ignition cycle period by a cycle factor to obtain the duration of the first sliding window, the method further includes: The cycle multiple is determined based on the mapping relationship between the engine speed and the cycle multiple; The higher the engine speed, the greater the cycle multiple.

[0012] In conjunction with the first aspect, in one implementation, performing sliding window filtering on the actual power generation based on the first sliding window includes: Calculate the average value of the actual power generation within the first sliding window, and replace the actual power generation at the center position within the first sliding window with the average value.

[0013] In conjunction with the first aspect, in one implementation, the demand power generation within the second sliding window is filtered by average value to obtain the corresponding average demand power generation, including: Divide the total demand for power generation within the second sliding window by the duration of the second sliding window to obtain the corresponding average demand for power generation.

[0014] In conjunction with the first aspect, in one implementation, obtaining the actual power output of the generator includes: Obtain the bus voltage and bus current of the generator; The actual power generation is obtained by multiplying the bus voltage and the bus current.

[0015] Secondly, this application provides an engine misfire diagnosis device, which includes: a statistics module, which is used to count the engine misfire count value when the range extender is in normal power generation condition, wherein a misfire count is recorded every time the engine operating state reaches a preset misfire detection state. The acquisition module is used to acquire the actual power generation and required power generation of the generator when the fire count value is greater than a preset count threshold. The determination module is used to determine whether the engine has a misfire fault based on the power error between the actual power generation and the required power generation within a set sliding window.

[0016] In conjunction with the second aspect, in one implementation, the determining module is further configured to: A first sliding window is set on the actual power generation, and the actual power generation is filtered by the first sliding window. After the sliding window filtering, the maximum value and minimum value of the actual power generation within the first sliding window are obtained. A second sliding window corresponding to the first sliding window is set on the demand power generation, and the demand power generation in the second sliding window is filtered by average value to obtain the corresponding average demand power generation. Based on the errors between the maximum and minimum actual power generation values ​​and the average required power generation value, it is determined whether the engine has a misfire fault.

[0017] In conjunction with the second aspect, in one implementation, the determining module is further configured to: Calculate the absolute value of the first difference between the maximum actual power generation and the average demanded power generation; Calculate the absolute value of the second difference between the minimum actual power generation and the average demanded power generation; If the absolute value of the first difference or the absolute value of the second difference is greater than a preset difference threshold, then it is determined that the engine has a misfire fault.

[0018] In conjunction with the second aspect, in one implementation, the determining module is further configured to: Calculate the ignition cycle of the engine based on the engine speed and the number of cylinders. Multiply the ignition cycle period by the cycle factor to obtain the duration of the first sliding window; Wherein, the period multiple is an integer.

[0019] In conjunction with the second aspect, in one implementation, the determining module is further configured to: The cycle multiple is determined based on the mapping relationship between the engine speed and the cycle multiple; The higher the engine speed, the greater the cycle multiple.

[0020] In conjunction with the second aspect, in one implementation, the determining module is further configured to: Calculate the average value of the actual power generation within the first sliding window, and replace the actual power generation at the center position within the first sliding window with the average value.

[0021] In conjunction with the second aspect, in one implementation, the determining module is further configured to: Divide the total demand for power generation within the second sliding window by the duration of the second sliding window to obtain the corresponding average demand for power generation.

[0022] In conjunction with the second aspect, in one implementation, the acquisition module is further configured to: Obtain the bus voltage and bus current of the generator; The actual power generation is obtained by multiplying the bus voltage and the bus current.

[0023] Thirdly, embodiments of this application provide a vehicle that includes an engine misfire diagnostic device as described in any of the preceding claims.

[0024] Fourthly, embodiments of this application provide an engine misfire diagnostic device, characterized in that the engine misfire diagnostic device includes a processor, a memory, and an engine misfire diagnostic program stored in the memory and executable by the processor, wherein when the engine misfire diagnostic program is executed by the processor, it implements the steps of the engine misfire diagnostic method as described in any of the above claims.

[0025] Fifthly, embodiments of this application provide a computer-readable storage medium, characterized in that the computer-readable storage medium stores an engine misfire diagnosis program, wherein when the engine misfire diagnosis program is executed by a processor, it implements the steps of the engine misfire diagnosis method as described in any of the preceding claims.

[0026] The beneficial effects of the technical solutions provided in this application include: This solution addresses the misfire detection problem in range extender systems where, under normal generator operation, the engine misfire count is recorded. Each time the engine reaches a preset misfire detection state, a misfire count is recorded. When the misfire count exceeds a preset threshold, the generator's actual and required power outputs are obtained. Based on the power error between the actual and required power outputs within a set sliding window, the system determines whether a misfire fault exists. This solution solves the technical problem in related technologies where, in range extender systems, slight changes in engine torque due to generator speed fluctuations lead to repeated crankshaft angular acceleration exceeding a threshold, resulting in false misfires. By introducing a comparison between actual and required power outputs and combining it with sliding window filtering technology, the accuracy and reliability of engine misfire diagnosis are effectively improved, reducing false alarms and missed alarms, and optimizing engine operation status monitoring and fault diagnosis capabilities. Attached Figure Description

[0027] Figure 1 This is a flowchart illustrating an embodiment of the engine misfire diagnosis method of this application; Figure 2 This is a schematic diagram of the functional modules of an embodiment of the engine misfire diagnostic device of this application; Figure 3 This is a schematic diagram of the hardware structure of the engine misfire diagnostic device involved in the embodiments of this application. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0029] In related technologies, the following methods are also used to determine whether an engine has misfired: Some methods determine whether an engine has misfired by comparing the magnitudes of the engine's output torque and the generator's output torque, or by comparing the generator's theoretical output torque (i.e., the given torque) with the actual output torque. If the actual torque is significantly lower, it is usually determined that the engine has misfired.

[0030] However, this method has significant limitations. There is a consistency issue between the engine and generator; even when the range extender is generating power normally, the actual output torque of the engine and the generator torque may deviate under certain operating conditions. Furthermore, generator torque is usually estimated based on current, and engine torque is usually estimated based on an engine bench calibration model; both are estimates and cannot fully and accurately reflect the actual torque situation. Especially when the engine is in a misfire state, the torque distortion becomes more severe, which can easily lead to false misfire reports.

[0031] Other methods use a table lookup approach with different engine speeds and torques to obtain a threshold for misfire angular acceleration, and then determine whether a misfire has occurred based on whether the engine's actual angular acceleration exceeds the threshold obtained from the table lookup.

[0032] The main problem with this method is that the calibration process for the judgment threshold is extremely complex. The judgment threshold is not only related to torque and speed, but also closely related to the current system state (such as engine cylinder pressure). Due to the interaction of these factors, the calibration value is difficult to fully cover all possible operating conditions. This means that under certain specific operating conditions, the threshold may become inapplicable, affecting the accuracy of misfire detection and leading to false alarms or missed misfires.

[0033] Therefore, this application provides an engine misfire diagnosis method, apparatus, equipment, medium, and vehicle to solve the aforementioned technical problems such as misjudgment and missed judgment in the engine misfire diagnosis process.

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0035] In a first aspect, embodiments of this application provide a method for diagnosing engine misfire.

[0036] In one embodiment, reference is made to Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the engine misfire diagnosis method of this application. Figure 1 As shown, engine misfire diagnosis methods include: Step S101: When the range extender is in normal power generation mode, count the engine misfire count, and record a misfire count each time the engine operation reaches the preset misfire detection state.

[0037] It's worth noting that the operating characteristics of a range extender may differ under different operating conditions. For example, during the start-up phase, the engine torque and speed may vary significantly, potentially causing fluctuations in generator power and affecting the accuracy of subsequent engine misfire diagnosis. However, under normal generator operation, the engine and generator operate relatively stably. Performing engine misfire diagnosis under these conditions avoids misjudgments caused by changes in operating conditions, thus ensuring the accuracy of the misfire diagnosis.

[0038] Optionally, in this embodiment, whenever the engine operating state reaches a preset misfire detection state, a misfire count is recorded, including: setting a crankshaft angular acceleration threshold for the engine based on the current engine speed and torque; when the engine crankshaft angular acceleration exceeds the set crankshaft angular acceleration threshold, the misfire count is incremented by 1.

[0039] Step S102: When the fire count value is greater than the preset count threshold, obtain the actual power generation and required power generation of the generator.

[0040] In one embodiment, obtaining the actual power generation of the generator includes: obtaining the bus voltage and bus current of the generator, and multiplying the bus voltage and the bus current to obtain the actual power generation.

[0041] The required power output of the generator can be obtained from the generator's control system. The generator control system typically calculates the required power output of the generator based on the vehicle's operating status (such as vehicle speed and load) and the charging needs of the vehicle's battery.

[0042] The counting threshold in this embodiment can be calibrated based on the actual parameters of the engine.

[0043] Step S103: Determine whether the engine has a misfire fault based on the power error between the actual power generation and the required power generation within the set sliding window.

[0044] In one embodiment, step S103 specifically includes the following steps: Step S301: Set a first sliding window on the actual power generation, perform sliding window filtering on the actual power generation according to the first sliding window, and obtain the maximum value and minimum value of the actual power generation within the first sliding window after sliding window filtering.

[0045] Specifically, setting a first sliding window on the actual power generation includes: Based on the engine's rotational speed and the number of cylinders, the ignition cycle of the engine is calculated; the ignition cycle is multiplied by a cycle factor to obtain the duration of the first sliding window; wherein the cycle factor is an integer.

[0046] As an example, let's assume an engine speed of 1600 rpm, a 4-cylinder engine, and a cycle multiple of 5. Here, 1600 rpm represents 1600 crankshaft revolutions per minute. A 4-cylinder engine ignites every two crankshaft revolutions; therefore, the ignition cycle of the engine is calculated as follows: T=

[0047] Where T is the engine's ignition cycle and f is the engine's ignition frequency.

[0048] The duration of the first sliding window is 5 = 93.75 .

[0049] In a preferred embodiment, the cycle multiple is determined based on the mapping relationship between the engine speed and the cycle multiple; wherein the higher the engine speed, the larger the cycle multiple. Since a higher engine speed results in a shorter ignition cycle, using a fixed cycle multiple in this case might lead to an excessively short sliding window duration, resulting in poor filtering. Increasing the cycle multiple ensures a sufficiently long sliding window duration to cover more ignition cycles, maintaining an appropriate sliding window duration at different engine speeds, thereby improving filtering performance and ensuring the accuracy and real-time performance of subsequent engine misfire diagnosis.

[0050] In a preferred embodiment, the actual power generation is filtered by sliding window according to the first sliding window, which includes: calculating the average value of the actual power generation within the first sliding window, and replacing the actual power generation at the center position within the first sliding window with the average value.

[0051] As an example, a first sliding window, five times the ignition cycle length, is used to slide across the data sequence of the generator's actual power output. The average value within this first sliding window is calculated and replaced with the original value at the center of the window, achieving data smoothing and noise reduction. Moving average is used as an example:

[0052] in For window size, For a moment The filtered value.

[0053] Next, after filtering, the maximum and minimum values ​​of the actual power generation within the first sliding window are obtained by scaling up and down the sliding window within the first sliding window.

[0054] It is worth noting that during the engine ignition cycle, there is usually some noise at a fixed frequency, which may originate from factors such as the reciprocating motion of the piston and electromagnetic interference. To effectively reduce the impact of this noise on engine performance monitoring and misfire diagnosis, this embodiment sets the sliding window filtering period of the first sliding window to an integer multiple of the ignition cycle period. This design can cancel out interference signals with the same frequency as the ignition cycle by calculating the average value of the data within the sliding window.

[0055] If the sliding window fails to fully cover one or more ignition cycles, the calculated mean may deviate from the true value because it fails to capture the entire physical process. By setting the sliding window filter period to a multiple of the ignition cycle period, it is ensured that each sliding window fully covers the entire ignition cycle of the engine, including the intake, compression, combustion, and exhaust stages. This multiple setting helps ensure that the window contains complete physical process data, thus more accurately reflecting the actual operating state of the engine when calculating the mean, significantly improving filtering accuracy and the reliability of misfire diagnosis.

[0056] Step S302: Set a second sliding window corresponding to the first sliding window on the demand power generation, and perform average value filtering on the demand power generation within the second sliding window to obtain the corresponding average demand power generation.

[0057] In one embodiment, the total demand for power generation within the second sliding window is divided by the duration of the second sliding window to obtain the corresponding average demand for power generation.

[0058] It is worth noting that by calculating the average value, fluctuations in demand for power generation over a short period of time can be smoothed out. This helps reduce drastic fluctuations in demand caused by instantaneous load changes or measurement noise, thus providing a more stable and reliable reference value for demand. This helps to more accurately determine whether there is a misfire in the engine and reduces misjudgments caused by fluctuations in demand.

[0059] Step S303: Determine whether the engine has a misfire fault based on the errors between the maximum and minimum actual power generation values ​​and the average required power generation value, respectively.

[0060] Specifically, the absolute value of the first difference between the maximum actual power generation and the average demand power generation is calculated; the absolute value of the second difference between the minimum actual power generation and the average demand power generation is calculated; if the absolute value of the first difference or the absolute value of the second difference is greater than a preset difference threshold, then it is determined that the engine has a misfire fault.

[0061] It is worth noting that traditional engine misfire diagnosis only considers misfire counts. When the threshold is set too low, the system may be overly sensitive to normal engine fluctuations, leading to false misfires. Conversely, when the threshold is set too high, the system may fail to detect actual misfire events in a timely manner, resulting in missed misfires. This application specifically considers engine characteristics, introducing the generator's required and actual power output, and sets a sliding window filtering time based on the ignition cycle multiple for different speed ranges to filter the actual power output. This design effectively eliminates false misfires caused by engine fluctuations in range extender systems. The system can not only adapt to the engine's operating characteristics under different conditions but also more accurately identify genuine misfire events.

[0062] Explanatoryly, compared with related technologies that only consider actual torque and preset torque, the misfire detection method of this application is more comprehensive and accurate. The principle calculation formula for the actual generator power output is P=n*T*η / 9550, where n is the generator speed (obtained by a speed sensor), T is the generator torque (usually an estimated value), and η is the system efficiency. In this embodiment, the actual power output P is obtained by multiplying the generator bus voltage U and bus current I to perform misfire diagnosis. As can be seen from the principle formula, not only the fluctuation of speed during misfire but also the fluctuation of torque during misfire is considered, thus making the misfire detection more accurate. This method based on actual measurements provides higher accuracy and reliability compared to using only estimated torque for misfire detection. In this way, the present invention can more accurately assess the engine's operating status, thereby improving the accuracy of misfire diagnosis and the overall performance of the system.

[0063] Secondly, embodiments of this application also provide an engine misfire diagnostic device.

[0064] In one embodiment, reference is made to Figure 2 , Figure 2 This is a functional module diagram of an embodiment of the engine misfire diagnostic device of this application. Figure 2 As shown, the engine misfire diagnostic device includes: The statistics module is used to count the engine misfire count when the range extender is in normal power generation mode. Each time the engine operation reaches the preset misfire detection state, a misfire count is recorded. The acquisition module is used to acquire the actual power generation and required power generation of the generator when the fire count value is greater than a preset count threshold. The determination module is used to determine whether the engine has a misfire fault based on the power error between the actual power generation and the required power generation within a set sliding window.

[0065] Furthermore, in one embodiment, the determining module is further configured to: A first sliding window is set on the actual power generation, and the actual power generation is filtered by the first sliding window. After the sliding window filtering, the maximum value and minimum value of the actual power generation within the first sliding window are obtained. A second sliding window corresponding to the first sliding window is set on the demand power generation, and the demand power generation in the second sliding window is filtered by average value to obtain the corresponding average demand power generation. Based on the errors between the maximum and minimum actual power generation values ​​and the average required power generation value, it is determined whether the engine has a misfire fault.

[0066] Furthermore, in one embodiment, the determining module is further configured to: Calculate the absolute value of the first difference between the maximum actual power generation and the average demanded power generation; Calculate the absolute value of the second difference between the minimum actual power generation and the average demanded power generation; If the absolute value of the first difference or the absolute value of the second difference is greater than a preset difference threshold, then it is determined that the engine has a misfire fault.

[0067] Furthermore, in one embodiment, the determining module is further configured to: Calculate the ignition cycle of the engine based on the engine speed and the number of cylinders. Multiply the ignition cycle period by the cycle factor to obtain the duration of the first sliding window; Wherein, the period multiple is an integer.

[0068] Furthermore, in one embodiment, the determining module is further configured to: The cycle multiple is determined based on the mapping relationship between the engine speed and the cycle multiple; The higher the engine speed, the greater the cycle multiple.

[0069] Furthermore, in one embodiment, the determining module is further configured to: Calculate the average value of the actual power generation within the first sliding window, and replace the actual power generation at the center position within the first sliding window with the average value.

[0070] Furthermore, in one embodiment, the determining module is further configured to: Divide the total demand for power generation within the second sliding window by the duration of the second sliding window to obtain the corresponding average demand for power generation.

[0071] Furthermore, in one embodiment, the acquisition module is further configured to: Obtain the bus voltage and bus current of the generator; The actual power generation is obtained by multiplying the bus voltage and the bus current.

[0072] The functions of each module in the aforementioned engine misfire diagnosis device correspond to the steps in the aforementioned engine misfire diagnosis method embodiment, and their functions and implementation processes will not be described in detail here.

[0073] Thirdly, embodiments of this application provide a vehicle including an engine misfire diagnostic device as described in any of the preceding claims. The vehicle's functionality corresponds to the steps in the aforementioned engine misfire diagnostic method embodiments, and its functions and implementation processes will not be elaborated upon here.

[0074] Fourthly, embodiments of this application provide an engine misfire diagnostic device, which can be a device with data processing capabilities, such as a vehicle controller or an on-board computer.

[0075] Reference Figure 3 , Figure 3 This is a schematic diagram of the hardware structure of the engine misfire diagnostic device involved in the embodiments of this application. In the embodiments of this application, the engine misfire diagnostic device may include a processor, a memory, a communication interface, and a communication bus.

[0076] The communication bus can be of any type and is used to interconnect the processor, memory, and communication interface.

[0077] The communication interface includes input / output (I / O) interfaces, physical interfaces, and logical interfaces used for interconnecting components within the engine misfire diagnostic equipment, as well as interfaces used for interconnecting the engine misfire diagnostic equipment with other devices (such as other computing devices or user equipment). Physical interfaces can be Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc.; user equipment can be displays, keyboards, etc.

[0078] Memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0079] The processor can be a general-purpose processor, which can call the engine misfire diagnostic program stored in the memory and execute the engine misfire diagnostic method provided in the embodiments of this application. For example, the general-purpose processor can be a central processing unit (CPU). The method executed when the engine misfire diagnostic program is called can be referred to in the various embodiments of the engine misfire diagnostic method of this application, and will not be repeated here.

[0080] Those skilled in the art will understand that Figure 3 The hardware structure shown does not constitute a limitation of this application and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0081] Fifthly, embodiments of this application also provide a computer-readable storage medium.

[0082] The present application provides a computer-readable storage medium storing an engine misfire diagnostic program, wherein when the engine misfire diagnostic program is executed by a processor, it implements the steps of the engine misfire diagnostic method described above.

[0083] The method implemented when the engine misfire diagnosis procedure is executed can be referred to in various embodiments of the engine misfire diagnosis method of this application, and will not be repeated here.

[0084] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0085] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.

[0086] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.

[0087] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0088] In some processes described in the embodiments of this application, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of this application, or they may be executed in parallel. The sequence number of the operation is only used to distinguish different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed sequentially or in parallel, and these operations or steps may be combined.

[0089] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of this application.

[0090] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method for diagnosing engine misfire, characterized in that, The engine misfire diagnosis method includes: When the range extender is in normal power generation mode, the engine misfire count is recorded. Each time the engine reaches the preset misfire detection state, a misfire count is recorded. When the fire count value is greater than the preset count threshold, the actual power generation and required power generation of the generator are obtained; Based on the power error between the actual power generation and the required power generation within the set sliding window, it is determined whether the engine has a misfire fault.

2. The engine misfire diagnosis method as described in claim 1, characterized in that, The step of determining whether the engine has a misfire fault based on the power error between the actual power generation and the required power generation within a set sliding window includes: A first sliding window is set on the actual power generation, and the actual power generation is filtered by the first sliding window. After the sliding window filtering, the maximum value and minimum value of the actual power generation within the first sliding window are obtained. A second sliding window corresponding to the first sliding window is set on the demand power generation, and the demand power generation in the second sliding window is filtered by average value to obtain the corresponding average demand power generation. Based on the errors between the maximum and minimum actual power generation values ​​and the average required power generation value, it is determined whether the engine has a misfire fault.

3. The engine misfire diagnosis method as described in claim 2, characterized in that, The step of determining whether the engine has a misfire fault based on the errors between the maximum and minimum actual power generation values ​​and the average demand power generation value, respectively, includes: Calculate the absolute value of the first difference between the maximum actual power generation and the average demanded power generation; Calculate the absolute value of the second difference between the minimum actual power generation and the average demanded power generation; If the absolute value of the first difference or the absolute value of the second difference is greater than a preset difference threshold, then it is determined that the engine has a misfire fault.

4. The engine misfire diagnosis method as described in claim 2, characterized in that, Setting a first sliding window on the actual power generation includes: Calculate the ignition cycle of the engine based on the engine speed and the number of cylinders. Multiply the ignition cycle period by the cycle factor to obtain the duration of the first sliding window; Wherein, the period multiple is an integer.

5. The engine misfire diagnosis method as described in claim 4, characterized in that, Before multiplying the ignition cycle period by a cycle factor to obtain the duration of the first sliding window, the method further includes: The cycle multiple is determined based on the mapping relationship between the engine speed and the cycle multiple; The higher the engine speed, the greater the cycle multiple.

6. The engine misfire diagnosis method as described in claim 2, characterized in that, Sliding window filtering of the actual power generation based on the first sliding window includes: Calculate the average value of the actual power generation within the first sliding window, and replace the actual power generation at the center position within the first sliding window with the average value.

7. The engine misfire diagnosis method as described in claim 2, characterized in that, The average value of the demand power generation within the second sliding window is filtered to obtain the corresponding average value of the demand power generation, including: Divide the total demand for power generation within the second sliding window by the duration of the second sliding window to obtain the corresponding average demand for power generation.

8. The engine misfire diagnosis method as described in claim 1, characterized in that, Obtaining the actual power output of the generator includes: Obtain the bus voltage and bus current of the generator; The actual power generation is obtained by multiplying the bus voltage and the bus current.

9. An engine misfire diagnostic device, characterized in that, The engine misfire diagnostic device includes: The statistics module is used to count the engine misfire count when the range extender is in normal power generation mode. Each time the engine operation reaches the preset misfire detection state, a misfire count is recorded. The acquisition module is used to acquire the actual power generation and required power generation of the generator when the fire count value is greater than a preset count threshold. The determination module is used to determine whether the engine has a misfire fault based on the power error between the actual power generation and the required power generation within a set sliding window.

10. The engine misfire diagnostic device as described in claim 9, characterized in that, The determining module is also used for: A first sliding window is set on the actual power generation, and the actual power generation is filtered by the first sliding window. After the sliding window filtering, the maximum value and minimum value of the actual power generation within the first sliding window are obtained. A second sliding window corresponding to the first sliding window is set on the demand power generation, and the demand power generation in the second sliding window is filtered by average value to obtain the corresponding average demand power generation. Based on the errors between the maximum and minimum actual power generation values ​​and the average required power generation value, it is determined whether the engine has a misfire fault.

11. The engine misfire diagnostic device as described in claim 10, characterized in that, The determining module is also used for: Calculate the absolute value of the first difference between the maximum actual power generation and the average demanded power generation; Calculate the absolute value of the second difference between the minimum actual power generation and the average demanded power generation; If the absolute value of the first difference or the absolute value of the second difference is greater than a preset difference threshold, then it is determined that the engine has a misfire fault.

12. The engine misfire diagnostic device as described in claim 10, characterized in that, The determining module is also used for: Calculate the ignition cycle of the engine based on the engine speed and the number of cylinders. Multiply the ignition cycle period by the cycle factor to obtain the duration of the first sliding window; Wherein, the period multiple is an integer.

13. A vehicle, characterized in that, Includes the engine misfire diagnostic device as described in any one of claims 9 to 12.

14. An engine misfire diagnostic device, characterized in that, The engine misfire diagnostic device includes a processor, a memory, and an engine misfire diagnostic program stored in the memory and executable by the processor, wherein when the engine misfire diagnostic program is executed by the processor, it implements the steps of the engine misfire diagnostic method as described in any one of claims 1 to 8.

15. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores an engine misfire diagnostic program, wherein when the engine misfire diagnostic program is executed by a processor, it implements the steps of the engine misfire diagnostic method as described in any one of claims 1 to 8.

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