Transmission fault diagnosis method and device and vehicle

Abstract

The invention discloses a transmission fault diagnosis method and device and a vehicle, and the method comprises the steps: obtaining the vehicle speed of the vehicle, and obtaining the wheel speed and gear information of the vehicle and the actual rotation speed of the input end of a transmission when the vehicle speed is greater than or equal to a vehicle speed threshold value; the theoretical rotating speed of the input end of the transmission is obtained based on the gear information and the wheel speed, and the rotating speed difference is obtained according to the actual rotating speed and the theoretical rotating speed; and whether a transmission of the vehicle breaks down or not is determined at least based on the size relation between the rotating speed difference and a preset rotating speed difference threshold value. According to the method, the device and the vehicle, the theoretical rotating speed of the input end of the transmission of the vehicle is obtained, the rotating speed difference value is obtained according to the actual rotating speed and the theoretical rotating speed of the input end of the transmission, whether the transmission breaks down or not is judged based on the relation between the rotating speed difference value and the rotating speed difference threshold value, and therefore accurate judgment of the transmission fault is achieved; and the driving safety of the vehicle is improved.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and more specifically to a method, apparatus and vehicle for diagnosing transmission faults. Background Technology

[0002] In recent years, consumers have placed increasingly higher demands on vehicle power and comfort, as well as fuel economy. For electric or hybrid four-wheel-drive vehicles, a two-speed transmission can be added to balance fuel economy and power. Electric or hybrid vehicles equipped with a two-speed transmission use different gears under different operating conditions. However, if the transmission wears down and develops mechanical failures due to prolonged use, and the fault is not diagnosed in time, it may lead to a sudden loss of power, posing a safety risk. Summary of the Invention

[0003] This application is made to address the aforementioned problems. According to one aspect of this application, a method for diagnosing transmission faults is provided. The method includes: acquiring the vehicle speed; when the vehicle speed is greater than or equal to a vehicle speed threshold, acquiring the wheel speeds, gear information, and actual rotational speed of the transmission input terminal; obtaining a theoretical rotational speed of the transmission input terminal based on the gear information and the wheel speeds, and obtaining a speed difference based on the actual rotational speed and the theoretical rotational speed; and determining whether the vehicle's transmission has malfunctioned, at least based on the relationship between the speed difference and a preset speed difference threshold.

[0004] In one embodiment of this application, the step of obtaining the theoretical speed of the transmission input end based on the gear information and the wheel speed, and obtaining the speed difference based on the actual speed and the theoretical speed, includes: when the gear information is a first gear, obtaining the first theoretical speed of the transmission input end based on the wheel speed and the first gear ratio, and obtaining the first speed difference based on the actual speed and the first theoretical speed.

[0005] In one embodiment of this application, determining whether the vehicle's transmission has malfunctioned based at least on the relationship between the speed difference and a preset speed difference threshold includes: determining that the transmission has malfunctioned when the first speed difference is greater than or equal to a first preset speed difference threshold.

[0006] In one embodiment of this application, determining whether the vehicle's transmission has malfunctioned based at least on the relationship between the speed difference and a preset speed difference threshold further includes: determining that the transmission has malfunctioned when the first speed difference is greater than or equal to a first preset speed difference threshold and the duration of the first speed difference being greater than or equal to the first preset speed difference threshold is greater than or equal to a first time threshold.

[0007] In one embodiment of this application, the step of obtaining the theoretical speed of the transmission input end based on the gear information and the wheel speed, and obtaining the speed difference based on the actual speed and the theoretical speed, includes: when the gear information is the second gear, obtaining the second theoretical speed of the transmission input end based on the wheel speed and the second gear transmission ratio, and obtaining the second speed difference based on the actual speed and the second theoretical speed; wherein the vehicle speed corresponding to the second gear is less than the vehicle speed corresponding to the first gear.

[0008] In one embodiment of this application, determining whether the vehicle's transmission has malfunctioned based at least on the relationship between the speed difference and a preset speed difference threshold includes: determining that the transmission has malfunctioned when the second speed difference is greater than or equal to the second preset speed difference threshold.

[0009] In one embodiment of this application, determining whether the vehicle's transmission has malfunctioned based at least on the relationship between the speed difference and a preset speed difference threshold further includes: determining that the transmission has malfunctioned when the second speed difference is greater than or equal to a second preset speed difference threshold and the duration of the second speed difference being greater than or equal to the second preset speed difference threshold is greater than or equal to a second time threshold.

[0010] In one embodiment of this application, the step of obtaining the theoretical speed of the transmission input based on the gear information and the wheel speed, and obtaining the speed difference based on the actual speed and the theoretical speed, includes: when the gear information is in neutral: obtaining the first theoretical speed based on the wheel speed and the first gear ratio, and obtaining the first speed difference based on the actual speed and the first theoretical speed; and / or, obtaining the second theoretical speed based on the wheel speed and the second gear ratio, and obtaining the second speed difference based on the actual speed and the second theoretical speed.

[0011] In one embodiment of this application, determining whether the vehicle's transmission has malfunctioned based at least on the relationship between the speed difference and a preset speed difference threshold includes: determining that the transmission has malfunctioned when the first speed difference is less than or equal to a third preset speed difference threshold; and / or, determining that the transmission has malfunctioned when the second speed difference is less than or equal to a fourth preset speed difference threshold.

[0012] In one embodiment of this application, determining whether the vehicle's transmission has malfunctioned based at least on the relationship between the speed difference and a preset speed difference threshold further includes: determining that the transmission has malfunctioned when the first speed difference is less than or equal to a third preset speed difference threshold and the duration for which the first speed difference is less than or equal to the third preset speed difference threshold is greater than or equal to a third time threshold; and / or, determining that the transmission has malfunctioned when the second speed difference is less than or equal to a fourth preset speed difference threshold and the duration for which the second speed difference is less than or equal to the fourth preset speed difference threshold is greater than or equal to a fourth time threshold.

[0013] In one embodiment of this application, determining whether the vehicle's transmission has malfunctioned based at least on the relationship between the speed difference and a preset speed difference threshold further includes: when the first speed difference is greater than the third preset speed difference threshold and the second speed difference is greater than the fourth preset speed difference threshold, determining whether the actual speed is greater than or equal to the preset speed threshold; and when the actual speed is greater than or equal to the preset speed threshold, determining that the transmission has malfunctioned.

[0014] In one embodiment of this application, determining whether the vehicle's transmission has malfunctioned based at least on the relationship between the speed difference and a preset speed difference threshold further includes: determining that the transmission has malfunctioned when the actual speed is greater than or equal to a preset speed threshold and the duration of the actual speed being greater than or equal to the preset speed threshold is greater than or equal to a fifth time threshold.

[0015] In one embodiment of this application, the method further includes: after determining that the transmission has malfunctioned, issuing an alarm and / or limiting the motor torque based on the malfunction.

[0016] According to another aspect of this application, a transmission fault diagnosis device is provided, the device including a processor and a memory, wherein the memory stores a computer-executable program executed by the processor, the computer-executable program causing the processor to perform the above-described transmission fault diagnosis method when executed by the processor.

[0017] According to another aspect of this application, a vehicle is provided that includes the aforementioned transmission fault diagnosis device.

[0018] According to another aspect of this application, a storage medium is provided that stores a computer program executed by a processor, which, when executed by the processor, causes the processor to perform the above-described transmission fault diagnosis method.

[0019] According to another aspect of this application, a computer program is provided, which stores a computer program that is executed by a processor, and when the computer program is executed by the processor, causes the processor to perform the above-described transmission fault diagnosis method.

[0020] The transmission fault diagnosis method, device, and vehicle of this application obtain the theoretical speed of the transmission input end of the vehicle, obtain the speed difference between the actual speed of the transmission input end and its theoretical speed, and determine whether the transmission is faulty based on the relationship between the speed difference and the speed difference threshold, thereby achieving accurate diagnosis of transmission faults and improving the safety of vehicle driving. Attached Figure Description

[0021] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0022] Figure 1 A schematic block diagram of an electronic device for a transmission fault diagnosis method and apparatus according to an embodiment of this application is shown.

[0023] Figure 2 A schematic flowchart of a transmission fault diagnosis method according to an embodiment of this application is shown.

[0024] Figure 3 A schematic flowchart illustrating the high-speed gear situation in the transmission fault diagnosis method according to an embodiment of this application is shown.

[0025] Figure 4 A schematic flowchart illustrating the low-speed gear situation in the transmission fault diagnosis method according to an embodiment of this application is shown.

[0026] Figure 5 A schematic flowchart illustrating the neutral gear condition in a transmission fault diagnosis method according to an embodiment of this application is shown.

[0027] Figure 6 A schematic structural block diagram of a transmission fault diagnosis device according to an embodiment of this application is shown. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application more apparent, exemplary embodiments according to this application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of this application, and not all of the embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein. Based on the embodiments of this application described herein, all other embodiments obtained by those skilled in the art without inventive effort should fall within the protection scope of this application.

[0029] First, refer to Figure 1 This describes an example electronic device 100 for implementing the transmission fault diagnosis method and apparatus of embodiments of the present invention.

[0030] like Figure 1 As shown, the electronic device 100 includes one or more processors 102, one or more storage devices 104, input devices 106, and output devices 108, which are interconnected via a bus system 110 and / or other forms of connection mechanisms (not shown). It should be noted that... Figure 1 The components and structure of the electronic device 100 shown are merely exemplary and not limiting; the electronic device may also have other components and structures as needed.

[0031] The processor 102 may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device 100 to perform desired functions.

[0032] The storage device 104 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 102 may execute the program instructions to implement the client functions (implemented by the processor) in the embodiments of the present invention described below, and / or other desired functions. Various applications and various data, such as various data used and / or generated by the applications, may also be stored in the computer-readable storage medium.

[0033] The input device 106 can be a device used by a user to input commands, and may include one or more of a keyboard, mouse, microphone, and touchscreen. Furthermore, the input device 106 can also be any interface for receiving information.

[0034] The output device 108 can output various information (e.g., images or sounds) to the outside (e.g., a user), and may include one or more of a display, speaker, etc. Furthermore, the output device 108 can also be any other device with output functionality.

[0035] For example, an example electronic device for implementing the transmission fault diagnosis method and apparatus according to embodiments of the present invention can be implemented such as a smart vehicle terminal.

[0036] Below, we will refer to Figure 2 This application describes a transmission fault diagnosis method 200 according to an embodiment of the present application. Figure 2 A schematic flowchart of a transmission fault diagnosis method 200 according to an embodiment of this application is shown. Figure 2 As shown, the transmission fault diagnosis method 200 according to an embodiment of this application may include the following steps:

[0037] In step S210, the vehicle speed is obtained. When the vehicle speed is greater than or equal to the vehicle speed threshold, the wheel speed, gear information and actual rotational speed of the transmission input are obtained.

[0038] In step S220, the theoretical speed of the transmission input is obtained based on the gear information and wheel speed, and the speed difference is obtained based on the actual speed and the theoretical speed.

[0039] In step S230, it is determined whether the vehicle's transmission has malfunctioned, based at least on the relationship between the speed difference and a preset speed difference threshold and the duration of the relationship.

[0040] In the embodiments of this application, the vehicle speed information is first acquired. The condition for further judgment is met only when the vehicle exceeds a certain speed. This is because the relationship between wheel speed and transmission input speed is used to determine whether the transmission system is functioning correctly. If the vehicle is stopped or traveling at a very low speed, the speed difference at the transmission input is not significant, affecting subsequent transmission system judgments. To ensure the accuracy of transmission system judgments, the vehicle speed must be greater than or equal to a certain speed threshold. When the vehicle speed is greater than or equal to this threshold, wheel speed, gear information, and the actual speed of the transmission input are acquired via the Controller Area Network (CAN). The theoretical speed of the transmission input can be calculated using the acquired gear information and wheel speed. The speed difference between the acquired actual speed and the calculated theoretical speed is then used to determine whether the speed difference is greater than or equal to a preset speed difference threshold. When the speed difference is greater than or equal to the preset speed difference threshold, it can be determined that the vehicle's transmission has malfunctioned. The speed at the vehicle's transmission input can be either the vehicle's electric motor speed or the vehicle's engine speed; no specific limitation is made.

[0041] Therefore, the transmission fault diagnosis method 200 according to the embodiments of this application obtains the theoretical speed of the transmission input end of the vehicle, obtains the speed difference between the actual speed of the transmission input end and its theoretical speed, and determines whether the transmission is faulty based on the relationship between the speed difference and the speed difference threshold, thereby achieving accurate judgment of transmission faults and improving the safety of vehicle driving.

[0042] In the embodiments of this application, step S210 involves obtaining the current vehicle speed and determining whether the speed is greater than or equal to a speed threshold. First, the current vehicle speed is obtained, and it is ensured that the vehicle speed is greater than or equal to a certain speed threshold. This is because the relationship between wheel speed and the rotational speed at the transmission input is used to determine whether the transmission system is functioning correctly. If the vehicle is stopped or traveling at a very low speed, the difference in rotational speed at the transmission input will not be significant, affecting subsequent judgments about the transmission system. To ensure the accuracy of the transmission system judgment, the vehicle speed must be greater than or equal to a certain speed threshold.

[0043] In embodiments of this application, when the vehicle speed is greater than or equal to a vehicle speed threshold, the wheel speeds, gear information, and actual rotational speed of the transmission input are obtained, and the theoretical rotational speed of the transmission input is obtained based on the gear information and wheel speeds. In one example, the actual and theoretical rotational speeds of the vehicle transmission input can be the actual and theoretical rotational speeds of the vehicle's electric motor; in another example, the actual and theoretical rotational speeds of the vehicle transmission input can be the actual and theoretical rotational speeds of the vehicle's engine.

[0044] Specifically, the following explanation uses the actual and theoretical speeds of the motor as the input speeds and theoretical speeds of the transmission. The vehicle's wheel speeds, transmission gear (gear information), and actual motor speed are obtained via CAN communication, a serial communication protocol bus used for real-time applications. Wheel speeds can be the left and right wheels of the transmission drive shaft, or the speeds of other wheels on the vehicle; there is no specific limitation. Gear information can be categorized as first gear, second gear, and neutral. The vehicle speed corresponding to the second gear is lower than that corresponding to the first gear. Specifically, the first gear can be a high gear, and the second gear can be a low gear. In one example, for an electric or hybrid four-wheel drive vehicle, to balance economy and power, a two-speed transmission with three switchable gears can be added: low gear, high gear, and neutral. Specifically, neutral is used for economical driving, switching the vehicle to two-wheel drive to reduce energy consumption; high gear is used for normal driving, allowing the vehicle to travel at high speeds in four-wheel drive; and low gear is used for extreme road conditions to increase wheel torque and improve off-road performance. By observing the different gears the transmission is in, the theoretical motor speed can be obtained based on the wheel speeds of the vehicle in different gears.

[0045] In the embodiments of this application, in step S220, the theoretical speed of the transmission input is obtained based on the gear information and wheel speed, and the speed difference is obtained based on the actual speed and the theoretical speed. When the gear information is the first gear, the first theoretical speed of the transmission input is obtained based on the wheel speed and the first gear ratio, and the first speed difference is obtained based on the actual speed and the first theoretical speed. Specifically, the first gear is described as a high-speed gear, as follows: Figure 3 As shown. In step S310, when the gear information is high gear (first gear), and the current vehicle speed is determined to be greater than or equal to the vehicle speed threshold, step S320 continues to obtain the theoretical speed of the high-speed motor (first theoretical speed) based on the wheel speed and the high-speed gear transmission ratio (first gear transmission ratio), and obtains the speed difference of the high-speed motor (first speed difference) based on the actual motor speed and the theoretical high-speed motor speed. Specifically, the wheel speed in high gear can be obtained through CAN communication. The transmission ratio refers to the ratio of the speeds of the two transmission mechanisms before and after the transmission device in the vehicle transmission system. The gear with the smaller transmission ratio is called the high gear, and the gear with the larger transmission ratio is called the low gear. The theoretical speed of the high-speed motor can be obtained based on the current wheel speed and the high-speed gear transmission ratio. Then, the speed difference of the motor in high gear is obtained by obtaining the actual motor speed in high gear and the theoretical high-speed motor speed through CAN communication.

[0046] In embodiments of this application, determining whether the vehicle's transmission has malfunctioned in step S230, at least based on the relationship between the speed difference and a preset speed difference threshold, includes: determining that the transmission has malfunctioned when the first speed difference is greater than or equal to a first preset speed difference threshold, and the duration for which the first speed difference is greater than or equal to the first preset speed difference threshold is greater than or equal to a first time threshold. Figure 3 When the first gear is in high gear, in step S330, if the motor speed difference value (i.e., the first speed difference) in high gear is greater than or equal to a certain motor speed difference threshold (i.e., the first preset speed difference threshold), it indicates that the speeds of the vehicle's motor and wheels are not synchronized. Step S340 then determines whether the duration for which the high-speed motor speed difference is greater than or equal to the first preset speed difference threshold is greater than or equal to a certain time (i.e., the first time threshold). If the duration is greater than or equal to the first time threshold, step S350 determines that the vehicle's transmission has malfunctioned in high gear.

[0047] In another embodiment, when the gear information is the first gear (i.e., high gear), if the preset speed difference threshold is large at this time, it indicates that the difference between the vehicle's motor speed and wheel speed is too large. Therefore, the transmission fault can be determined directly when the motor speed difference value (i.e., the first speed difference) in the high gear condition is greater than or equal to a certain motor speed difference threshold (i.e., the first preset speed difference threshold).

[0048] In the embodiments of this application, the theoretical speed at the input end of the transmission is obtained based on gear information and wheel speed, and the speed difference is obtained based on the actual speed and the theoretical speed. This includes: when the gear information is the second gear, obtaining the second theoretical speed at the input end of the transmission based on the wheel speed and the transmission ratio of the second gear, and obtaining the second speed difference based on the actual speed and the second theoretical speed. The vehicle speed corresponding to the second gear is less than the vehicle speed corresponding to the first gear. Specifically, the second gear is described as a low gear, such as... Figure 4 As shown, in step S410, when the gear information is low gear, if the current vehicle speed is greater than or equal to the vehicle speed threshold, the wheel speed in low gear can be obtained through CAN communication. In step S420, the theoretical motor speed in low gear (i.e., the second theoretical speed) can be obtained based on the wheel speed and the low gear transmission ratio (i.e., the second gear transmission ratio). Then, the actual motor speed is obtained through CAN communication. The difference between the actual motor speed and the theoretical low gear motor speed (i.e., the second speed difference) is obtained. The subsequent transmission status is confirmed based on this difference.

[0049] In embodiments of this application, determining whether a vehicle's transmission has malfunctioned is based at least on the relationship between the speed difference and a preset speed difference threshold, and the duration of this relationship. This includes determining that the transmission has malfunctioned when a second speed difference is greater than or equal to a second preset speed difference threshold, and the duration of this relationship is greater than or equal to a second time threshold. Specifically, as... Figure 4 As shown, when the second gear is a low gear, in step S430, based on the obtained low gear motor speed difference (second speed difference), it is determined whether the low gear motor speed difference is greater than or equal to a certain motor speed difference threshold (second preset speed difference threshold). In step S440, if the low gear motor speed difference is greater than or equal to the certain motor speed difference threshold, it indicates that the speeds of the vehicle's motor and wheels are not synchronized in low gear. The duration for which the low gear motor speed difference is greater than or equal to the second motor speed difference threshold is then determined. If the duration is greater than or equal to the second time threshold, in step S450, it can be determined that the vehicle's transmission has malfunctioned in low gear. Specifically, the first time threshold and the second time threshold can be equal. The second preset speed difference threshold (i.e., the motor speed difference threshold in low gear) is less than the first preset speed difference threshold (i.e., the motor speed difference threshold in high gear).

[0050] In another embodiment, when the gear information is the second gear (i.e., low gear), if the preset speed difference threshold is large at this time, it indicates that the difference between the vehicle's motor speed and wheel speed is too large. Therefore, the transmission fault can be determined directly when the motor speed difference value (i.e., the second speed difference) in the low gear condition is greater than or equal to a certain motor speed difference threshold (i.e., the second preset speed difference threshold).

[0051] In the embodiments of this application, the theoretical speed at the input end of the transmission is obtained based on gear information and wheel speed, and the speed difference is obtained based on the actual speed and the theoretical speed, including: when the gear information is neutral: a first theoretical speed is obtained based on wheel speed and the first gear ratio, and a first speed difference is obtained based on the actual speed and the first theoretical speed; and / or, a second theoretical speed is obtained based on wheel speed and the second gear ratio, and a second speed difference is obtained based on the actual speed and the second theoretical speed. Specifically, the first gear can be a high gear, the second gear can be a low gear, and the vehicle speed in the low gear condition is less than the vehicle speed in the high gear condition. The following is in conjunction with... Figure 5 To describe the process in neutral, such as Figure 5As shown, in step S510, when the vehicle's transmission is in neutral, it is still necessary to first determine whether the current vehicle speed is greater than or equal to a speed threshold. This is because the relationship between wheel speed and motor speed is used to determine if the transmission system is functioning correctly. If the vehicle is stationary or traveling at a very low speed, the difference in motor speed will not be significant, affecting subsequent transmission system assessments. To ensure the accuracy of transmission system assessments, the vehicle speed must be greater than or equal to a certain speed threshold.

[0052] In this embodiment, the wheel speed, transmission gear (gear information), and actual motor speed in neutral mode can be obtained via CAN communication. In step S520, the theoretical speed of the high-speed motor (first theoretical speed) can be obtained based on the wheel speed and the high-speed gear ratio (first gear ratio). Then, the speed difference between the high-speed motor in neutral mode and the theoretical speed of the high-speed motor in neutral mode (first speed difference) is obtained. And / or, the theoretical speed of the low-speed motor (second theoretical speed) can be obtained based on the wheel speed and the low-speed gear ratio (second gear ratio). Then, the speed difference between the low-speed motor in neutral mode and the theoretical speed of the low-speed motor in neutral mode (second speed difference) is obtained. Because in neutral mode, the vehicle's transmission is not engaged in any gear, and when the transmission malfunctions, there may be unexpected shifts to high or low gears, therefore, it is necessary to determine the motor speed difference between high and low gear modes.

[0053] In embodiments of this application, determining whether a vehicle's transmission has malfunctioned is based at least on the relationship between the speed difference and a preset speed difference threshold, and the duration of this relationship. This includes: determining a transmission malfunction when a first speed difference is less than or equal to a third preset speed difference threshold, and the duration of this relationship is greater than or equal to a third time threshold; and / or, determining a transmission malfunction when a second speed difference is less than or equal to a fourth preset speed difference threshold, and the duration of this relationship is greater than or equal to a fourth time threshold. (Continuing with...) Figure 5 In step S530, when the transmission is in neutral, if the calculated high-speed motor speed difference (first speed difference) is less than or equal to a certain speed difference threshold (third preset speed difference threshold), it indicates that the vehicle's transmission has mistakenly shifted to a high-speed position, potentially indicating a transmission malfunction. Step S540 then determines whether the duration for which the high-speed motor speed difference (first speed difference) in neutral is less than or equal to the third preset speed difference threshold is greater than or equal to a third time threshold. If this duration is also greater than or equal to the third time threshold, step S570 confirms that the vehicle's transmission has malfunctioned. If the duration is less than the third time threshold, then the vehicle's transmission has not malfunctioned.

[0054] In this embodiment, when the transmission is in neutral, if the calculated low-speed motor speed difference (second speed difference) in step S530 is less than or equal to a certain speed difference threshold (fourth preset speed difference threshold), it indicates that the vehicle's transmission has been mistakenly switched to a low-speed position, potentially indicating a transmission malfunction. Step S540 then determines whether the duration for which the low-speed motor speed difference (second speed difference) in neutral is less than or equal to the fourth preset speed difference threshold is greater than or equal to a fourth time threshold. If this duration is also greater than or equal to the fourth time threshold, step S570 confirms that the vehicle's transmission has malfunctioned. If the duration is less than the fourth time threshold, the vehicle's transmission has not malfunctioned. In one example, the third preset speed difference threshold (i.e., the motor speed difference threshold for determining whether a mistaken switch to a high-speed gear has occurred in neutral) can be equal to the first preset speed difference threshold, and the fourth preset speed difference threshold (i.e., the motor speed difference threshold for determining whether a mistaken switch to a low-speed gear has occurred in neutral) can be equal to the second preset speed difference threshold, wherein the third preset speed difference threshold is greater than the fourth preset speed difference threshold. In another example, the third preset speed difference threshold may not be equal to the first preset speed difference threshold, and the fourth preset speed difference threshold may not be equal to the second preset speed difference threshold. The first time threshold, the second time threshold, the third time threshold, and the fourth time threshold may be equal.

[0055] In another embodiment, when the preset speed difference threshold is small, that is, when the third preset speed difference threshold is small, it indicates that the vehicle's motor speed is close to the wheel speed in the first gear (i.e., high gear), and the transmission has mistakenly switched to high gear. Therefore, the transmission fault can be determined directly by the first speed difference being less than or equal to the third preset speed difference threshold. And / or, when the fourth preset speed difference threshold is small, it indicates that the vehicle's motor speed is close to the wheel speed in the second gear (i.e., low gear), and the transmission has mistakenly switched to low gear. Therefore, the transmission fault can be determined directly by the second speed difference being less than or equal to the fourth preset speed difference threshold.

[0056] In embodiments of this application, determining whether a vehicle's transmission has malfunctioned, at least based on the relationship between the speed difference and a preset speed difference threshold, further includes: when a first speed difference is greater than a third preset speed difference threshold and a second speed difference is greater than a fourth preset speed difference threshold, determining whether the actual speed is greater than or equal to a preset speed threshold; and when the actual speed is greater than or equal to the preset speed threshold, and the duration of the actual speed being greater than or equal to the preset speed threshold is greater than or equal to a fifth time threshold, determining that the transmission has malfunctioned. (Continuing to refer to...) Figure 5When the transmission is in neutral, if the calculated difference in motor speed between high and low gears (first speed difference) is greater than a third preset speed difference threshold, it indicates that the vehicle's transmission has not mistakenly shifted to a high gear. Simultaneously, if the calculated difference in motor speed between low and high gears (second speed difference) is greater than a fourth preset speed difference threshold, it indicates that the vehicle's transmission has not mistakenly shifted to a low gear. After confirming that the transmission has not mistakenly shifted to either a high or low gear, the actual motor speed in neutral, obtained through CAN communication, can be used for further determination.

[0057] In this embodiment, in step S550, when the actual motor speed in neutral is greater than or equal to a certain speed threshold (i.e., a preset speed threshold), and in step S560, when the duration of the actual motor speed being greater than or equal to the preset speed threshold is greater than or equal to a fifth time threshold, it can be determined in step S570 that the vehicle's transmission has malfunctioned. Specifically, the preset speed threshold is greater than the speed difference threshold between high and low gears, and the fifth time threshold is greater than the time threshold between high and low gears. This is because when the vehicle's transmission is in neutral, the motor in neutral will not output power and will stop rotating. If the motor continues to rotate (i.e., the actual motor speed has a certain value) and the motor rotation is maintained for a certain period of time, it can be determined that the vehicle's transmission has malfunctioned.

[0058] In another embodiment, when the gear information is neutral, the motor will stop rotating because it will not output power. If the actual speed of the motor is greater than or equal to the preset speed threshold when the preset speed threshold is large, that is, when the motor has a relatively high speed, it can be directly determined that the vehicle's transmission has malfunctioned.

[0059] In the embodiments of this application, after a transmission malfunction is determined, an alarm is triggered and / or the motor torque is limited based on the malfunction. Specifically, when a transmission malfunctions, the vehicle can issue an alarm based on the transmission malfunction, and at the same time, the motor torque can be limited. Motor torque limiting primarily restricts the vehicle's output power to a very low level or eliminates it altogether, thereby ensuring vehicle driving safety.

[0060] Therefore, the transmission fault diagnosis method according to the embodiments of this application obtains the theoretical speed of the transmission input end of the vehicle, obtains the speed difference between the actual speed of the transmission input end and its theoretical speed, and determines whether the transmission is faulty based on the relationship between the speed difference and the speed difference threshold, thereby achieving accurate judgment of transmission faults and improving the safety of vehicle driving.

[0061] The following is combined with Figure 6 Describes a transmission fault diagnosis device provided according to another aspect of this application. Figure 6 A schematic structural block diagram of a transmission fault diagnosis device 600 according to an embodiment of this application is shown. Figure 6 As shown, the transmission fault diagnosis device 600 includes a memory 610 and a processor 620. The memory 610 stores a computer-executable program that is run by the processor 620. When the computer-executable program is run by the processor 620, the processor 620 executes the transmission fault diagnosis method 200 described above. Those skilled in the art can understand the structure and specific operation of each module in the transmission fault diagnosis device 600 according to the embodiments of this application based on the foregoing description; for brevity, these details are not repeated here. Therefore, the transmission fault diagnosis device according to the embodiments of this application obtains the theoretical speed of the motor at the transmission input end, calculates the speed difference between the actual speed at the transmission input end and its theoretical speed, and determines whether the transmission is faulty based on the relationship between the speed difference and the speed difference threshold, thereby achieving accurate judgment of transmission faults and improving vehicle driving safety.

[0062] Furthermore, according to embodiments of this application, a vehicle is also provided, which may include the transmission fault diagnosis device 600 described above.

[0063] Furthermore, this application also provides a storage medium storing a computer program thereon, which, when run by a processor, causes the processor to execute the transmission fault diagnosis method 200 described above according to an embodiment of this application. The storage medium may, for example, include a memory card of a smartphone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disc read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

[0064] In addition, this application also provides a computer program having stored thereon a computer program that is executed by a processor, wherein when the computer program is executed by the processor, the processor causes the processor to perform the aforementioned transmission fault diagnosis method 200.

[0065] Based on the above description, the transmission fault diagnosis method, device, and vehicle of this application embodiment obtain the theoretical speed of the motor at the transmission input end, obtain the speed difference between the actual speed at the transmission input end and its theoretical speed, and determine whether the transmission is faulty based on the relationship between the speed difference and the speed difference threshold, thereby achieving accurate judgment of transmission faults and improving the safety of vehicle driving.

[0066] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of this application. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of this application. All such changes and modifications are intended to be included within the scope of this application as claimed in the appended claims.

[0067] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0068] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed.

[0069] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of this application may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0070] Similarly, it should be understood that, in order to streamline this application and aid in understanding one or more of the various inventive aspects, features of this application may sometimes be grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of this application. However, this approach should not be construed as reflecting an intention that the claimed application requires more features than are expressly recited in each claim. Rather, as reflected in the corresponding claims, its inventive point lies in solving the corresponding technical problem with features fewer than all features of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of this application.

[0071] Those skilled in the art will understand that, apart from the mutual exclusion of features, all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or apparatus so disclosed can be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0072] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0073] The various component embodiments of this application can be implemented in hardware, or as software modules running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some modules according to the embodiments of this application. This application can also be implemented as a program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such a program implementing this application can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

[0074] It should be noted that the above embodiments are illustrative of this application and not limiting of it, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. This application can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. These words can be interpreted as names.

[0075] The above description is merely a specific embodiment or illustration of the embodiments of this application. The scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. The scope of protection of this application shall be determined by the scope of the claims.

Claims

1. A transmission failure diagnosis method characterized by comprising: The method comprises: obtaining a vehicle speed of a vehicle, when the vehicle speed is greater than or equal to a vehicle speed threshold, obtaining a wheel speed of the vehicle, gear information and an actual speed of a transmission input end; obtaining a theoretical speed of the transmission input end based on the gear information and the wheel speed, and obtaining a speed difference based on the actual speed and the theoretical speed; determining whether the transmission of the vehicle has a fault based on at least a size relationship between the speed difference and a preset speed difference threshold.

2. The method of claim 1, wherein, The method comprises: when the gear information is a first gear, obtaining a first theoretical speed of the transmission input end based on the wheel speed and a first gear transmission ratio, and obtaining a first speed difference based on the actual speed and the first theoretical speed.

3. The method of claim 2, wherein, The method comprises: when the first speed difference is greater than or equal to a first preset speed difference threshold, it is determined that the transmission has a fault.

4. The method of claim 2, wherein, The method further comprises: when the first speed difference is greater than or equal to the first preset speed difference threshold, and a duration for which the first speed difference is greater than or equal to the first preset speed difference threshold is greater than or equal to a first time threshold, it is determined that the transmission has a fault.

5. The method according to claim 3 or 4, characterized in that, The method comprises: when the gear information is a second gear, obtaining a second theoretical speed of the transmission input end based on the wheel speed and a second gear transmission ratio, and obtaining a second speed difference based on the actual speed and the second theoretical speed; wherein the second gear corresponds to a vehicle speed that is less than the vehicle speed corresponding to the first gear.

6. The method of claim 5, wherein, The method comprises: when the second speed difference is greater than or equal to a second preset speed difference threshold, it is determined that the transmission has a fault.

7. The method of claim 5, wherein, The method further comprises: when the second speed difference is greater than or equal to the second preset speed difference threshold, and a duration for which the second speed difference is greater than or equal to the second preset speed difference threshold is greater than or equal to a second time threshold, it is determined that the transmission has a fault.

8. The method of claim 5, wherein, The method comprises: when the gear information is a neutral gear, obtaining the first theoretical speed based on the wheel speed and the first gear transmission ratio, and obtaining the first speed difference based on the actual speed and the first theoretical speed; and / or, The second theoretical rotation speed is obtained based on the wheel rotation speed and the second gear transmission ratio, and the second rotation speed difference is obtained according to the actual rotation speed and the second theoretical rotation speed.

9. The method of claim 8, wherein, The determination of whether the transmission of the vehicle is malfunctioning based on at least the size relationship between the rotation speed difference and a preset rotation speed difference threshold value comprises: when the first rotation speed difference is less than or equal to a third preset rotation speed difference threshold value, it is determined that the transmission is malfunctioning; and / or, when the second rotation speed difference is less than or equal to a fourth preset rotation speed difference threshold value, it is determined that the transmission is malfunctioning.

10. The method of claim 8, wherein, The determination of whether the transmission of the vehicle is malfunctioning based on at least the size relationship between the rotation speed difference and a preset rotation speed difference threshold value further comprises: when the first rotation speed difference is less than or equal to a third preset rotation speed difference threshold value, and the duration that the first rotation speed difference is less than or equal to the third preset rotation speed difference threshold value is greater than or equal to a third time threshold value, it is determined that the transmission is malfunctioning; and / or, when the second rotation speed difference is less than or equal to a fourth preset rotation speed difference threshold value, and the duration that the second rotation speed difference is less than or equal to the fourth preset rotation speed difference threshold value is greater than or equal to a fourth time threshold value, it is determined that the transmission is malfunctioning.

11. The method according to claim 9 or 10, characterized in that, The determination of whether the transmission of the vehicle is malfunctioning based on at least the size relationship between the rotation speed difference and a preset rotation speed difference threshold value further comprises: when the first rotation speed difference is greater than the third preset rotation speed difference threshold value, and the second rotation speed difference is greater than the fourth preset rotation speed difference threshold value, it is determined whether the actual rotation speed is greater than or equal to a preset rotation speed threshold value; when the actual rotation speed is greater than or equal to the preset rotation speed threshold value, it is determined that the transmission is malfunctioning.

12. The method of claim 8, wherein, The determination of whether the transmission of the vehicle is malfunctioning based on at least the size relationship between the rotation speed difference and a preset rotation speed difference threshold value further comprises: when the actual rotation speed is greater than or equal to a preset rotation speed threshold value, and the duration that the actual rotation speed is greater than or equal to the preset rotation speed threshold value is greater than or equal to a fifth time threshold value, it is determined that the transmission is malfunctioning.

13. The method of claim 1, wherein, The method further comprises: after determining that the transmission is malfunctioning, performing an alarm and / or motor torque limitation based on the malfunction.

14. A transmission failure diagnosis device characterized by comprising: The device comprises a memory and a processor, wherein the memory stores a computer executable program run by the processor, and the computer executable program, when run by the processor, causes the processor to perform the transmission malfunction diagnosis method of any one of claims 1-13.

15. A vehicle characterized by comprising: The vehicle comprises the transmission malfunction diagnosis device of claim 14.

16. A storage medium, characterized by The storage medium stores a computer program run by a processor, and the computer program, when run by the processor, causes the processor to perform the transmission malfunction diagnosis method of any one of claims 1-13.

17. A computer program, characterized in that, The computer program stores a computer program run by a processor, and the computer program, when run by the processor, causes the processor to perform the transmission malfunction diagnosis method of any one of claims 1-13.

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