Engine rotating speed filtering method and system for instrument display

Abstract

An engine rotating speed filtering method for instrument display comprises the steps that the rotating speed state of an engine is determined according to the collected engine rotating speed, the engine rotating speed displayed by an instrument and the opening degree of an accelerator; when the rotating speed state is in a variable speed state, filtering the currently collected engine rotating speed through first filtering intensity; when the rotating speed state is in the idling state, the currently-collected engine rotating speed is filtered through second filtering intensity; when the rotating speed state is in a constant speed state and meets a preset filtering condition, filtering the currently collected rotating speed of the engine through third filtering intensity; wherein the first filtering intensity is lt; a second filtering strength lt; and third filtering intensity. By distinguishing the rotating speed state of the engine, filtering is carried out on the collected rotating speed data of the engine by adopting different filtering intensities, and the response speed of an instrument pointer is adjusted in a targeted manner, so that the instantaneity, the accuracy and the stability of rotating speed display in the instrument can be effectively improved.

Description

Technical Field

[0001] The present application relates to the field of instrument technology, and in particular to an engine speed filtering method and system for instrument display. Background Art

[0002] In traditional internal combustion engine commercial vehicles, engine speed is a key indicator of operating status and is typically displayed prominently on the instrument panel. Its display directly influences the driver's perception of vehicle operating conditions. Typically, the speed data displayed on the instrument panel isn't directly obtained from the sensor, but rather indirectly from the ECU (Electronic Control Unit) responsible for collecting speed data via the CAN (Controller Area Network) bus. The ECU filters the raw speed value before transmission, so the instrument system only requires simple additional filtering to meet requirements.

[0003] For traditional instruments that use physical pointers, the response speed of the pointer is slow due to structural limitations. The problem of unstable display can be effectively avoided through preliminary filtering by the ECU and additional filtering by the instrument system. However, in full LCD instruments, the virtual pointer is not subject to physical limitations and has a very fast response speed. If the original simple filtering solution is continued to be used, the pointer will cause jitter, resulting in a visual "blurred" effect. To solve this problem, a common solution is to increase the filtering strength. However, although the current filtering strength enhancement technology can effectively reduce the jitter of the pointer, it will also reduce the response speed of the instrument pointer, thereby affecting the immediacy and accuracy of the speed information transmitted to the instrument, resulting in unstable instrument pointer display. Summary of the Invention

[0004] The present application provides an engine speed filtering method and system for instrument display, which can solve the technical problem of poor instrument speed display stability in the current full liquid crystal instrument speed display technology.

[0005] To achieve the above objectives, in a first aspect, the present application provides an engine speed filtering method for instrument display, the method comprising:

[0006] The engine speed state is determined based on the collected engine speed, the engine speed displayed on the instrument, and the throttle opening.

[0007] When the speed state is in the speed changing state, the currently collected engine speed is filtered using the first filtering strength.

[0008] When the speed state is in the idle state, the currently collected engine speed is filtered using the second filtering strength.

[0009] When the speed state is in a uniform speed state and meets the preset filtering conditions, the currently collected engine speed is filtered using the third filtering intensity.

[0010] Among them, the first filtering strength < the second filtering strength < the third filtering strength.

[0011] Furthermore, in one embodiment, determining the engine speed state based on the collected engine speed, the engine speed displayed by the instrument, and the throttle opening includes:

[0012] Calculate the speed difference between the currently collected engine speed and the engine speed currently displayed on the instrument.

[0013] When the speed difference is greater than the preset difference threshold, and the number of times it is greater than the preset difference threshold is greater than the preset count threshold, the speed state is in the speed change state; otherwise, if the current throttle opening is 0 and the currently collected engine speed is within the preset idle range, the speed state is in the idle state.

[0014] If the speed state is neither in the shifting state nor in the idling state, it is determined to be in the constant speed state.

[0015] Furthermore, in one embodiment, the number of times the speed difference is greater than a preset difference threshold is obtained by a cumulative counter: each time the speed difference is greater than the preset difference threshold, the value of the cumulative counter increases by 1.

[0016] Furthermore, in one embodiment, the preset filtering condition is: the speed difference between the currently collected engine speed and the engine speed currently displayed on the instrument is in the same direction as the current cumulative difference, and the current cumulative difference is greater than a preset cumulative threshold.

[0017] The current cumulative difference is: the cumulative result of the same-direction differences when the speed is in a constant speed state.

[0018] Furthermore, in one embodiment, when the speed difference between the currently collected engine speed and the engine speed currently displayed on the instrument is calculated for the first time, the current accumulated difference is the speed difference calculated this time.

[0019] Furthermore, in one embodiment, when the rotation speed difference value calculated this time is opposite to the rotation speed difference value calculated last time, the current accumulated difference value is reset to zero.

[0020] Furthermore, in one embodiment, after the currently collected engine speed is filtered using the first filtering strength or the third filtering strength, the filtered speed is used to update the engine speed currently displayed on the instrument.

[0021] Furthermore, in one embodiment, after filtering the currently collected engine speed using the second filtering strength, the method further includes:

[0022] A response dead zone value is set. If the absolute value of the difference between the filtered speed and the engine speed currently displayed on the instrument is greater than or equal to the response dead zone value, the filtered speed is used to update the engine speed currently displayed on the instrument; otherwise, the engine speed currently displayed on the instrument is not updated.

[0023] Furthermore, in one embodiment, when the speed is in a constant speed state and does not meet the preset filtering conditions, the currently collected engine speed is not filtered, and the engine speed currently displayed on the instrument is not updated.

[0024] In a second aspect, based on the above-mentioned engine speed filtering method for instrument display, the present application provides an engine speed filtering system for the engine speed filtering method for instrument display, the system comprising:

[0025] The speed status module is used to determine the engine speed status based on the collected engine speed, the engine speed displayed by the instrument, and the throttle opening.

[0026] The first filtering module is configured to filter the currently collected engine speed using a first filtering intensity when the speed state is in a variable speed state.

[0027] The second filtering module is used to filter the currently collected engine speed using a second filtering intensity when the speed state is in an idle state.

[0028] The third filtering module is used to filter the currently collected engine speed through a third filtering strength when the speed state is in a uniform speed state and meets the preset filtering conditions.

[0029] The beneficial effects of the technical solutions provided in the embodiments of the present application include:

[0030] This application determines the engine speed state based on the collected engine speed, the engine speed displayed on the instrument, and the throttle opening; when the speed state is in a variable speed state, the currently collected engine speed is filtered using a first filter strength; when the speed state is in an idle state, the currently collected engine speed is filtered using a second filter strength; when the speed state is in a uniform speed state and meets the preset filtering conditions, the currently collected engine speed is filtered using a third filter strength, and the first filter strength < the second filter strength < the third filter strength. By distinguishing the speed state of the vehicle engine, different filter strengths are adopted for filtering the currently collected engine speed for different speed states. Under different speed states, the instrument pointer response speed can be adjusted in a targeted manner, thereby improving the immediacy and accuracy of the speed information transmitted to the instrument, thereby effectively improving the stability of the instrument speed display. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a flow chart of an engine speed filtering method for instrument display according to an embodiment of the present application.

[0032] Figure 2 This is a flowchart of the detailed steps of step S1 of the embodiment of this application.

[0033] Figure 3 This is a block diagram of an engine speed filtering system for instrument display according to an embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] First, it should be noted that analysis of engine speed data on the CAN (Controller Area Network) bus shows that after filtering by the engine ECU (Electronic Control Unit), most speed jitter caused by acquisition or anomalies has been filtered out. The remaining data fluctuations mainly come from the following three situations:

[0036] (1) Control jitter: When the ECU adjusts the engine speed, the actual speed is unlikely to be completely stable and will fluctuate around the target speed. This jitter has a high frequency and a small amplitude, and the waveform is usually close to a sine wave or a triangle wave.

[0037] (2) Idle jitter: This type of jitter only occurs when the engine is idling and is generated when the engine is running. Its waveform is characterized by a rapid rise and slow fall, with a sawtooth-like shape. This type of jitter is usually large in amplitude and has a long period. It can even be heard by the human ear as a periodic fluctuation in the sound of the engine running.

[0038] (3) Abnormal jitter: This type of jitter is caused by data acquisition or other reasons and has no specific pattern. Since the front-end ECU has already performed filtering, the amplitude of this type of jitter is generally small and the probability of occurrence is also very low.

[0039] Based on the main sources of data fluctuations mentioned above and the characteristics of the engine speed displayed by the instrument, the engine speed state can be divided into variable speed state, idle state, and constant speed state, and the filtering strength of the three states is analyzed:

[0040] (1) Speed ​​​​change state: When the speed is changing, the pointer itself is moving rapidly. In this case, it is meaningless to eliminate jitter by enhancing the filtering. Instead, it will slow down the display response. Therefore, only very simple filtering is needed to smooth the movement of the pointer.

[0041] (2) Idle state: When the vehicle is stationary, the throttle opening is 0. At this time, the vehicle environment is relatively stable and the driver is more sensitive to speed fluctuations. Therefore, this is the scenario that requires the most stringent filtering.

[0042] (3) Constant Speed: Commercial vehicles typically travel on highways for extended periods of time, maintaining an economical speed for most of the time, with minimal changes in speed or rotational speed. However, due to vehicle movement and driver control of speed, the speed can still change slowly. In this scenario, the key is to accurately respond to subtle speed changes while filtering out jitter.

[0043] Since the speed filter strength is proportional to the instrument's response speed to the speed, that is, the greater the filter strength, the slower the response speed, and the smaller the filter strength, the faster the response speed. In combination with the above analysis, this application proposes an engine speed filtering method for instrument display, which performs different filtering strengths for different speed states, in order to balance the filter strength and response speed under different speed states and enhance the stability of the instrument speed display.

[0044] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0045] In a first aspect, an embodiment of the present application provides an engine speed filtering method for an instrument display, the method comprising:

[0046] The engine speed state is determined according to the collected engine speed, the engine speed displayed by the instrument, and the throttle opening; three filter intensities are set respectively, and the first filter intensity < the second filter intensity < the third filter intensity.

[0047] When the speed state is in the speed changing state, the currently collected engine speed is filtered using the first filtering strength.

[0048] When the speed state is in the idle state, the currently collected engine speed is filtered using the second filtering strength.

[0049] When the speed state is in a uniform speed state and meets the preset filtering conditions, the currently collected engine speed is filtered using the third filtering intensity.

[0050] This application first determines the engine speed state by collecting the actual engine speed, the speed displayed by the instrument, and the throttle opening. According to different speed states, different filter intensities are adopted to filter the collected engine speed: the first filter intensity is adopted in the variable speed state, the second filter intensity is adopted in the idle state, and the third filter intensity is adopted when the speed is constant and the preset conditions are met. The first filter intensity is less than the second filter intensity, and the second filter intensity is less than the third filter intensity. By distinguishing different speed states and adopting targeted filter intensities, this method can effectively improve the response speed of the instrument pointer and the immediacy and accuracy of the speed information, thereby improving the stability of the instrument speed display.

[0051] In one embodiment, see Figure 1 As shown, a specific embodiment of the above engine speed filtering method is provided. In this embodiment, the engine speed filtering method includes the following steps:

[0052] S1. Determine the engine speed state based on the collected engine speed, the engine speed displayed on the instrument, and the throttle opening. When the speed state is in the shifting state, proceed to step S2. When the speed state is in the idling state, proceed to step S3. When the speed state is in the uniform speed state, proceed to step S5.

[0053] The engine speed collected above refers to the actual engine speed measured by the speed sensor, and the engine speed displayed on the above instrument refers to the speed displayed on the vehicle dashboard.

[0054] S2. Filter the currently collected engine speed using a first filtering strength, and proceed to step S7.

[0055] S3. Filter the currently collected engine speed using a second filtering strength, and set a response dead zone value.

[0056] S4. Determine whether the absolute value of the difference between the rotation speed after the second filtering strength and the engine rotation speed currently displayed on the instrument is greater than or equal to the response dead zone value. If so, proceed to step S7; if not, proceed to step S8.

[0057] S5. Determine whether the preset filtering conditions are met. If so, proceed to step S6; if not, proceed to step S8.

[0058] S6. Filter the currently collected engine speed using a third filtering strength, and proceed to step S7.

[0059] S7. Use the filtered speed to update the engine speed currently displayed on the instrument.

[0060] S8. Continue to display the current engine speed displayed on the instrument.

[0061] The filtering condition in step S5 is that the speed difference between the currently acquired engine speed and the engine speed currently displayed on the instrument is in the same direction or equal to the current cumulative difference, and the current cumulative difference is greater than a preset cumulative threshold. The same direction means that the speed difference and the current cumulative difference are both positive or negative. The current cumulative difference is the cumulative result of the same-direction speed differences when the speed is in a constant speed state. The current cumulative difference is calculated as follows:

[0062] When the speed difference between the currently collected engine speed and the engine speed currently displayed on the instrument is first calculated, the calculated speed difference is directly used as the current cumulative difference. Each subsequent speed difference calculation, if the currently calculated speed difference is in the same direction as the previously calculated speed difference, the currently calculated speed difference is added to the current cumulative difference. Conversely, if the currently calculated speed difference is in the opposite direction of the previously calculated speed difference (i.e., one of the currently calculated speed difference and the previously calculated speed difference is positive and the other is negative), the current cumulative difference is reset to zero.

[0063] In this embodiment, the magnitude relationship among the first filtering strength, the second filtering strength, and the third filtering strength is: first filtering strength < second filtering strength < third filtering strength.

[0064] In this embodiment, by setting the response dead zone in step S3, unnecessary display fluctuations can be reduced, thereby improving the stability and reliability of the instrument display. By combining mean filtering and response dead zone, idle jitter can be effectively smoothed while avoiding excessive response of the pointer to small changes.

[0065] Further, in one embodiment, see Figure 2 As shown, in the above step S1, the engine speed state is determined according to the collected engine speed, the engine speed displayed by the instrument, and the throttle opening. The specific steps are:

[0066] S101: Calculate the speed difference between the currently collected engine speed and the engine speed currently displayed on the instrument.

[0067] S102: Determine whether the speed difference is greater than a preset difference threshold. If so, proceed to step S103; if not, proceed to step S105.

[0068] S103, determine whether the number of times the speed difference is greater than the preset difference threshold is greater than the preset counting threshold, if so, go to step S104, if not, go to step S105.

[0069] S104: Determine whether the current speed state is a speed change state.

[0070] S105: Determine whether the current throttle opening is 0 and the currently collected engine speed is within the preset idle range. If so, proceed to step S106; if not, proceed to step S107.

[0071] S106: Determine whether the current speed state is an idle state.

[0072] S107: Determine whether the current speed state is a uniform speed state.

[0073] In this embodiment, the speed difference between the currently acquired engine speed and the engine speed currently displayed on the instrument is first calculated. If the speed difference is greater than a preset difference threshold, a further determination is made as to whether the number of times the speed difference exceeds the threshold is greater than a preset count threshold. If the number of times the speed difference exceeds the threshold is also greater than the preset count threshold, the current speed state is determined to be a variable speed state. If the speed difference is less than or equal to the preset threshold, or the number of times the speed difference exceeds the threshold does not reach the preset count threshold, a determination is made as to whether the following two conditions are simultaneously met: the current throttle opening is 0 and the currently acquired engine speed is within a preset idle range. If both conditions are met, the current speed state is determined to be an idle state; otherwise, the current speed state is determined to be a constant speed state.

[0074] Furthermore, in one embodiment, the number of times the speed difference is greater than the preset difference threshold in the above step S103 can be obtained by a cumulative counter, and the value of the cumulative counter increases by 1 each time the speed difference is greater than the preset difference threshold.

[0075] Furthermore, in one embodiment, in the above step S2, filtering the currently collected engine speed by the first filtering strength can be achieved by a first-order lag filtering method with a smaller coefficient. The calculation formula (1) of the first-order lag filtering method is:

[0076] V o =V i ×β+V l×(1-β) (1),

[0077] Among them, V o Indicates the speed after filtering, V i Indicates the collected engine speed, V l It indicates the engine speed displayed on the instrument, β indicates the filter coefficient, and its value range is between 0 and 1. The larger the filter coefficient, the smaller the corresponding filter strength. Conversely, the smaller the filter coefficient, the greater the corresponding filter strength.

[0078] Furthermore, in one embodiment, in the above step S3, filtering the currently collected engine speed by the second filtering strength can be achieved by a long-period mean filtering method, and its calculation formula (2) is:

[0079]

[0080] Among them, m represents the mth cycle, O m represents the speed after filtering in the mth cycle, k represents the number of selected cycles, I m Indicates the currently collected engine speed of the mth cycle.

[0081] Furthermore, in one embodiment, in the above step S6, filtering the currently collected engine speed using the third filtering strength can be achieved by a first-order lag filtering method with a larger coefficient.

[0082] Furthermore, in one embodiment, by collecting and analyzing the speed data of the engine of a certain vehicle model, the following data is obtained:

[0083] The engine's idle speed is approximately between 550 and 600 rpm. The jitter fluctuation period at idle is approximately 500 milliseconds, with an amplitude of approximately 10 to 15 rpm. Furthermore, the control jitter period is approximately 80 ms, with an amplitude of approximately 3 to 5 rpm. Within the half-hour data collection, two spikes were observed, both with amplitudes within 10 rpm.

[0084] The tachometer dial on this model has an opening angle of 240°, covering a 0-3000 rpm range. Idle jitter causes the gauge needle to vibrate within a range of 1.8° at a frequency of 2 Hz, resulting in an unstable, constantly moving needle. Control jitter, on the other hand, causes the needle to vibrate within a range of 0.6° at a frequency of 12 Hz, making the needle edge appear blurred.

[0085] For this vehicle, the engine speed threshold should cover the amplitude of idle jitter and is therefore set at 20 rpm or higher. The motion count threshold is set to 2, meaning that if the speed change exceeds 20 rpm for two consecutive cycles, the speed is considered to be changing rapidly. In this case, using a weaker filter coefficient allows the pointer to quickly follow the speed changes.

[0086] When the speed changes are stable, it's necessary to determine whether the engine is idling. If it is idling, the stability of the speed displayed on the instrument is more important than accuracy and response speed. Using a long-period mean filter can effectively filter out idle jitter. The filter period should be at least longer than the idle jitter period, for example, 500ms or 1000ms. In addition, setting a deadband in the range of 3 to 5rpm after filtering can achieve a very stable indication effect.

[0087] When the speed is constant, setting a cumulative difference threshold can filter out control jitter to a certain extent. A value of 2 to 3 times the control jitter amplitude is generally appropriate. Because the threshold is cumulative, it can be increased appropriately. For this vehicle model, the cumulative difference threshold is set to 20 rpm. When the cumulative difference exceeds this threshold, it indicates that the engine speed displayed on the instrument panel is deviating from the actual engine speed. At this time, stronger filtering is applied to slowly approximate the actual engine speed, improving the accuracy of the engine speed display on the instrument panel.

[0088] In a second aspect, based on the above embodiment of the engine speed filtering method for instrument display, an embodiment of an engine speed filtering system for instrument display is provided. Figure 3 As shown, the above system includes a speed state module, a first filtering module, a second filtering module, and a third filtering module. Specifically:

[0089] The speed status module is used to determine the engine speed status based on the collected engine speed, the engine speed displayed by the instrument, and the throttle opening.

[0090] The first filtering module is configured to filter the currently collected engine speed using a first filtering intensity when the speed state is in a variable speed state.

[0091] The second filtering module is used to filter the currently collected engine speed using a second filtering intensity when the speed state is in an idle state.

[0092] The third filtering module is used to filter the currently collected engine speed through a third filtering strength when the speed state is in a uniform speed state and meets the preset filtering conditions.

[0093] In order to solve the problem of pointer jitter when the engine speed of traditional internal combustion engine commercial vehicles is displayed on a full LCD instrument, this application proposes an engine speed filtering method for instrument display. This method is a segmented filtering algorithm that aims to balance response speed and display stability, while avoiding the computing power burden caused by complex filtering algorithms to a certain extent. By collecting the actual engine speed, the speed displayed by the instrument, and the throttle opening, the engine speed state is judged, and different filtering strategies are adopted according to different speed states: a weaker first filtering strength is adopted in the variable speed state, a medium second filtering strength is adopted in the idle state, and a stronger third filtering strength is adopted in the uniform speed state and when the preset conditions are met. The filtered speed is used to update the engine speed displayed on the instrument. This segmented filtering method has a simple structure and low computing power requirements. It can effectively improve the response speed of the instrument pointer and the immediacy and accuracy of the speed information, thereby improving the stability of the instrument speed display.

[0094] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0095] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0096] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0097] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0098] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0099] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, of course, it 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 the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of the present application.

[0100] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for filtering engine speed for instrument display, characterized in that: The method comprises: Determine the engine speed status based on the collected engine speed, the engine speed displayed on the instrument, and the throttle opening; When the speed state is in a variable speed state, filtering the currently collected engine speed using a first filtering intensity; When the speed state is in the idle state, filtering the currently collected engine speed by a second filtering strength; When the speed state is in a uniform speed state and meets the preset filtering conditions, the currently collected engine speed is filtered using a third filtering strength; Among them, the first filtering strength < the second filtering strength < the third filtering strength.

2. The engine speed filtering method for instrument display according to claim 1, characterized in that: Determining the engine speed state based on the collected engine speed, the engine speed displayed by the instrument, and the throttle opening includes: Calculate the speed difference between the currently collected engine speed and the engine speed currently displayed on the instrument; When the speed difference is greater than a preset difference threshold, and the number of times it is greater than the preset difference threshold is greater than a preset count threshold, the speed state is in the speed change state; otherwise, if the current throttle opening is 0 and the currently collected engine speed is within the preset idle range, the speed state is in the idle state; If the speed state is neither in the shifting state nor in the idling state, it is determined to be in the constant speed state.

3. The engine speed filtering method for instrument display according to claim 2, characterized in that: The number of times the speed difference is greater than the preset difference threshold is obtained by an accumulating counter: each time the speed difference is greater than the preset difference threshold, the value of the accumulating counter increases by 1.

4. The engine speed filtering method for instrument display according to claim 1, characterized in that: The preset filtering condition is: the speed difference between the currently collected engine speed and the engine speed currently displayed by the instrument is in the same direction as the current cumulative difference, and the current cumulative difference is greater than the preset cumulative threshold; The current cumulative difference is: the cumulative result of the same-direction differences when the speed is in a constant speed state.

5. The engine speed filtering method for instrument display according to claim 4, characterized in that: When the speed difference between the currently collected engine speed and the engine speed currently displayed on the instrument is calculated for the first time, the current accumulated difference is the speed difference calculated this time.

6. The engine speed filtering method for instrument display according to claim 4, characterized in that: When the speed difference value calculated this time is opposite to the speed difference value calculated last time, the current accumulated difference value is reset to zero.

7. The engine speed filtering method for instrument display according to claim 1, characterized in that: After the currently acquired engine speed is filtered using the first filtering intensity or the third filtering intensity, the filtered speed is used to update the engine speed currently displayed on the instrument.

8. The engine speed filtering method for instrument display according to claim 1, characterized in that: After filtering the currently acquired engine speed by the second filtering strength, the method further includes: A response dead zone value is set. If the absolute value of the difference between the filtered speed and the engine speed currently displayed on the instrument is greater than or equal to the response dead zone value, the filtered speed is used to update the engine speed currently displayed on the instrument; otherwise, the engine speed currently displayed on the instrument is not updated.

9. The engine speed filtering method for instrument display according to claim 1, characterized in that: When the speed is in a constant speed state and does not meet the preset filtering conditions, the currently collected engine speed is not filtered and the engine speed displayed on the current instrument is not updated.

10. An engine speed filtering system based on the engine speed filtering method for instrument display according to any one of claims 1 to 9, characterized in that: The system comprises: The speed status module is used to determine the engine speed status based on the collected engine speed, the engine speed displayed by the instrument, and the throttle opening; a first filtering module, configured to filter the currently collected engine speed using a first filtering intensity when the speed state is in a variable speed state; a second filtering module, configured to filter the currently collected engine speed using a second filtering intensity when the speed state is in an idle state; The third filtering module is used to filter the currently collected engine speed through a third filtering strength when the speed state is in a uniform speed state and meets the preset filtering conditions.

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