Speed ratio monitoring method for vehicle carrying automatic gearbox and related device

Abstract

The invention discloses a speed ratio monitoring method for a vehicle carrying an automatic gearbox and a related device. In the process of gear shifting based on a target speed ratio, if the current vehicle speed is larger than or equal to a first vehicle speed threshold value, it is indicated that gear shifting is conducted based on the target speed ratio; the engine or motor rotating speed may be dragged to the maximum allowable rotating speed by the wheel rotating speed due to clutch combination, and a target speed ratio fault is determined. In order to ensure the safety of the vehicle, if a target speed ratio fault is determined, the vehicle is not controlled to be shifted to a target gear at the current vehicle speed, a transmission chain is controlled to be disengaged to interrupt power transmission, and the target gear is updated to a neutral gear, so that the gearbox does not transmit power, or the input and the output of the gearbox are disconnected; the rotating speed of the engine or the motor is not dragged to be higher than the maximum allowable rotating speed by the rotating speed of the wheels due to clutch combination, so that sudden unpowered output caused by damage of the engine or the motor is avoided, non-driver expected deceleration of the vehicle is avoided, and the safety is improved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a speed ratio monitoring method and related device for a vehicle equipped with an automatic transmission. Background Art

[0002] The automobile transmission ratio, also known as the speed ratio, refers to the ratio of the rotational speeds of the two transmission mechanisms before and after the speed change device in the automobile transmission system.

[0003] In the related art, vehicles equipped with automatic transmissions will perform gear shifting based on the gear shifting map to change the vehicle's speed ratio. However, during the gear shifting preparation or shifting process, the engine or motor may be damaged, causing a sudden loss of power output, which may cause the vehicle to decelerate unexpectedly, resulting in low safety. Summary of the invention

[0004] In response to the above problems, the present application provides a speed ratio monitoring method and related devices for a vehicle equipped with an automatic transmission, which are used to avoid deceleration of the vehicle that is not expected by the driver and improve the safety of the vehicle.

[0005] Based on this, the embodiments of the present application disclose the following technical solutions:

[0006] On the one hand, an embodiment of the present application provides a method for monitoring the speed ratio of a vehicle equipped with an automatic transmission, the method comprising:

[0007] In the process of shifting gears based on a target speed ratio, obtaining a current vehicle speed, wherein the target speed ratio is a speed ratio required to shift the current gear to the target gear;

[0008] If the current vehicle speed is greater than or equal to a first vehicle speed threshold, determining that the target speed ratio is faulty, the first vehicle speed threshold being determined based on a maximum allowable speed of the engine or the motor;

[0009] If it is determined that the target speed ratio fails, the transmission chain is disengaged to interrupt power transmission, and the target gear is updated to neutral.

[0010] Optionally, the first vehicle speed threshold is determined as follows:

[0011]

[0012] Among them, V2 is the first vehicle speed threshold, InputSpeedMax is the maximum allowable speed of the engine or the motor; Offset_2 is the deviation safety threshold corresponding to the target gear; i is the total speed ratio of the gearbox corresponding to the target speed ratio; R is the tire radius.

[0013] Optionally, the method further includes:

[0014] Obtain handle position signal and vehicle speed signal;

[0015] If the first and second conditions are met, the step of determining a target speed ratio failure if the current vehicle speed is greater than or equal to a first vehicle speed threshold is performed;

[0016] Among them, the first condition is that the handle position signal is valid and the vehicle speed signal is valid; the second condition is that the handle position signal indicates that the handle is in the forward position or the reverse position, or the vehicle has power transmission.

[0017] Optionally, the method further includes:

[0018] During the current speed ratio control process corresponding to the current vehicle speed, if the transmission chain disengagement control is determined based on the command current of the clutch, the step of determining a target speed ratio failure if the current vehicle speed is greater than or equal to a first vehicle speed threshold is executed.

[0019] Optionally, in the process of shifting gears based on the target speed ratio, before obtaining the current vehicle speed, the method further includes:

[0020] Acquire the real-time vehicle speed and a second vehicle speed threshold corresponding to the current gear, wherein the second vehicle speed threshold is determined based on the maximum allowable speed of the engine or the motor and the engine speed surge margin;

[0021] If the real-time vehicle speed is equal to the second vehicle speed threshold, the target speed ratio is determined based on the second vehicle speed threshold, and a shift operation is performed based on the target speed ratio.

[0022] Optionally, the second vehicle speed threshold is determined as follows:

[0023]

[0024] Among them, V1 is the second vehicle speed threshold, InputSpeedMax is the maximum allowable speed of the engine or the motor; Offset_1 is the engine speed increase margin; i is the total speed ratio of the gearbox corresponding to the target speed ratio; and R is the tire radius.

[0025] On the other hand, the present application provides a vehicle speed ratio monitoring device equipped with an automatic transmission, the device comprising: an acquisition unit, a determination unit, and an execution unit;

[0026] The acquisition unit is used to acquire the current vehicle speed during the gear shifting process based on the target speed ratio, wherein the target speed ratio is the speed ratio required to shift the current gear to the target gear;

[0027] The determination unit is configured to determine a target speed ratio failure if the current vehicle speed is greater than or equal to a first vehicle speed threshold, wherein the first vehicle speed threshold is determined based on a maximum allowable speed of an engine or a motor;

[0028] The execution unit is used for controlling the disengagement of the transmission chain to interrupt the power transmission and updating the target gear position to neutral if it is determined that the target speed ratio fails.

[0029] As a possible implementation manner, the determining unit 202 is further configured to determine the first vehicle speed threshold. The first vehicle speed threshold is determined as follows:

[0030]

[0031] Among them, V2 is the first vehicle speed threshold, InputSpeedMax is the maximum allowable speed of the engine or the motor; Offset_2 is the deviation safety threshold corresponding to the target gear; i is the total speed ratio of the gearbox corresponding to the target speed ratio; R is the tire radius.

[0032] Optionally, the acquisition unit 1 is further used to:

[0033] Obtain handle position signal and vehicle speed signal;

[0034] The execution unit is further used for:

[0035] If the first and second conditions are met, the step of determining a target speed ratio failure if the current vehicle speed is greater than or equal to a first vehicle speed threshold is performed;

[0036] Among them, the first condition is that the handle position signal is valid and the vehicle speed signal is valid; the second condition is that the handle position signal indicates that the handle is in the forward position or the reverse position, or the vehicle has power transmission.

[0037] Optionally, the execution unit is further used for:

[0038] During the current speed ratio control process corresponding to the current vehicle speed, if the transmission chain disengagement control is determined based on the command current of the clutch, the step of determining a target speed ratio failure if the current vehicle speed is greater than or equal to a first vehicle speed threshold is executed.

[0039] Optionally, the acquisition unit is further used to:

[0040] In the process of shifting gears based on the target speed ratio, before obtaining the current vehicle speed, obtaining the real-time vehicle speed and a second vehicle speed threshold value corresponding to the current gear, wherein the second vehicle speed threshold value is determined based on the maximum allowable speed of the engine or the motor and the engine speed rise margin;

[0041] The execution unit is further used for:

[0042] If the real-time vehicle speed is equal to the second vehicle speed threshold, the target speed ratio is determined based on the second vehicle speed threshold, and a shift operation is performed based on the target speed ratio.

[0043] Optionally, the determining unit is further used to determine the second vehicle speed threshold, and the second vehicle speed threshold is determined as follows:

[0044]

[0045] Among them, V1 is the second vehicle speed threshold, InputSpeedMax is the maximum allowable speed of the engine or the motor; Offset_1 is the engine speed increase margin; i is the total speed ratio of the gearbox corresponding to the target speed ratio; and R is the tire radius.

[0046] In another aspect, the present application provides a computer device, the device comprising a processor and a memory:

[0047] The memory is used to store program code and transmit the program code to the processor;

[0048] The processor is used to execute the method described in the above aspects according to the instructions in the program code.

[0049] On the other hand, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method described in the above aspects.

[0050] On the other hand, an embodiment of the present application provides a computer program product or a computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the method described in the above aspects.

[0051] The advantages of the above technical solution of this application are:

[0052] The current vehicle speed in the current gear is obtained. If the current vehicle speed is greater than or equal to the first vehicle speed threshold, the target speed ratio determined based on the current vehicle speed, or the speed ratio required to change from the current gear to the target gear, may cause the wheel speed to drag the engine or motor speed to above the maximum allowable speed due to the clutch engagement. At this time, a target speed ratio failure is determined. In order to ensure vehicle safety, if a target speed ratio failure is determined, the vehicle will not be controlled to shift to the target gear at the current speed, but the transmission chain will be controlled to be disengaged to interrupt power transmission, and the target gear will be updated to neutral, so that the gearbox does not transmit power, or the input and output of the gearbox are disconnected, and the wheel speed will not drag the engine or motor speed to above the maximum allowable speed due to the clutch engagement, so that the engine or motor will not be damaged and cause a sudden lack of power output, thereby avoiding the vehicle from decelerating unexpectedly by the driver, thereby improving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0054] Figure 1 A flow chart of speed ratio monitoring of a vehicle equipped with an automatic transmission provided in this application;

[0055] Figure 2 A schematic diagram of a vehicle speed ratio monitoring device equipped with an automatic transmission provided in the present application;

[0056] Figure 3 A structural diagram of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0057] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0058] In the related art, vehicles equipped with automatic transmissions will perform gear shifting based on the gear shifting diagram to change the vehicle's speed ratio. However, after research, it was found that during the gear shifting preparation or shifting process, based on the target gear determined at the current vehicle speed, the wheel speed may drag the engine or motor speed to above the maximum allowable speed due to the clutch engagement, which may cause damage to the engine or motor and cause a sudden loss of power output, resulting in the vehicle's unexpected deceleration, which is less safe.

[0059] Based on this, the embodiment of the present application provides a vehicle speed ratio monitoring method and related devices equipped with an automatic transmission, and in the process of shifting gears based on the target speed ratio, the current vehicle speed in the current gear is obtained. If the current vehicle speed is greater than or equal to the first vehicle speed threshold, it means that shifting gears based on the target speed ratio may cause the wheel speed to drag the engine or motor speed to above the maximum allowable speed due to the engagement of the clutch. At this time, the target speed ratio failure is determined. In order to ensure the safety of the vehicle, if the target speed ratio failure is determined, the vehicle will not be controlled to shift to the target gear at the current speed, but the transmission chain will be disengaged to interrupt the power transmission, and the target gear will be updated to neutral to avoid the wheel speed from dragging the engine or motor speed to above the maximum allowable speed due to the engagement of the clutch, which may cause damage to the engine or motor and cause a sudden lack of power output, thereby causing the vehicle to decelerate beyond the driver's expectation, and the safety is low.

[0060] Combine the following Figure 1 , a method for monitoring the speed ratio of a vehicle equipped with an automatic transmission provided in an embodiment of the present application is introduced. Figure 1 The method shown in the embodiment may be executed by an electronic control unit (ECU) included in a vehicle, for example. Figure 1 , this figure is a flow chart of a method for monitoring the speed ratio of a vehicle equipped with an automatic transmission provided in an embodiment of the present application, and the method may include S101-S103.

[0061] S101: During a gear shifting process based on a target speed ratio, a current vehicle speed is obtained.

[0062] The target speed ratio is the speed ratio required to change the current gear of the vehicle to the target gear, where the current gear is the gear the vehicle is currently in, and the target gear is the gear the vehicle is about to change to. For example, the speed ratio required to change from 1st gear to 2nd gear is the target speed ratio.

[0063] It should be noted that there is a one-to-one correspondence between the gear position and the speed ratio, and the target gear position can be determined based on the target speed ratio, or in other words, the process of shifting gears based on the target speed ratio can be the process of shifting gears based on the target gear position.

[0064] In addition, in some special circumstances, such as during bench testing experiments, the actual gear and the target gear may both be 1st gear, or the target speed ratio may be consistent with the current speed ratio, but the vehicle speed is very high. There may also be a problem that the vehicle drags the engine or motor to the maximum allowable speed due to the engagement of the clutch. Therefore, when the actual gear and the target gear are consistent, a speed ratio monitoring method for a vehicle equipped with an automatic transmission provided in an embodiment of the present application can also be used.

[0065] S102: If the current vehicle speed is greater than or equal to the first vehicle speed threshold, it is determined that the target speed ratio is faulty.

[0066] The first vehicle speed threshold is determined based on the maximum allowable speed of the engine or motor. If the current vehicle speed is greater than or equal to the first vehicle speed threshold, the rotational inertia of the automatic transmission input to the wheels in the target gear will be very large. In the process of shifting gears based on the target speed ratio, the clutch engagement may cause the wheel speed to drag the engine or motor speed to above the maximum allowable speed, which may cause damage to the engine or motor and cause a sudden lack of power output, thereby causing the vehicle to decelerate unexpectedly by the driver, and the safety is low.

[0067] Based on this, when the current vehicle speed is greater than or equal to the first vehicle speed threshold, a target speed ratio failure can be determined. For example, a prompt of a target speed ratio failure is issued so that the driver knows that deceleration will occur, thereby giving the driver enough psychological expectations and reducing safety risks.

[0068] As a possible implementation, if the current vehicle speed is greater than or equal to the first vehicle speed threshold and the duration is greater than a preset time threshold, a target speed ratio fault is determined. A condition for the duration of the current vehicle speed being greater than or equal to the first vehicle speed threshold is added to improve the reliability of determining a target speed ratio fault.

[0069] As a possible implementation method, the first vehicle speed threshold can be based on the maximum allowable speed of the engine or motor plus the deviation safety threshold, and then converted to the vehicle speed at the wheel end through the total speed ratio of the automatic transmission. The determination method of the first vehicle speed threshold can refer to formula (1):

[0070]

[0071] Among them, V2 is the first vehicle speed threshold, InputSpeedMax is the maximum allowable speed of the engine or motor, in rpm; Offset_2 is the deviation safety threshold corresponding to the target gear, in rpm; i is the total speed ratio of the gearbox corresponding to the target speed ratio; R is the tire radius, in m.

[0072] It should be noted that Offset_2 can be obtained by looking up a table based on the target speed ratio. The table records the corresponding relationship between the speed ratio corresponding to each gear and the deviation safety threshold. The table can be obtained based on bench performance testing. In addition, the greater the moment of inertia input from the automatic transmission to the wheel end in a certain gear, the smaller the Offset_2. Therefore, after the speed ratio conversion, the greater the speed ratio (or the lower the target gear), the smaller the first vehicle speed threshold.

[0073] As a possible implementation, the handle position signal and the vehicle speed signal can be obtained. If conditions one and two are met, S102 is executed. Among them, condition one is that the handle position signal is valid and the vehicle speed signal is valid, such as after the handle position signal and the vehicle speed signal are verified respectively, both are available; condition two is that the handle position signal indicates that the handle is in the forward position (D) or the reverse position (R), or the vehicle has power transmission. For example, whether the vehicle has power transmission can be judged based on the control command current of the gearbox actuator. For another example, if the number and type of clutches combined with the planetary gear do not match the corresponding gear position, it is considered that the vehicle has no power transmission.

[0074] It should be noted that when the handle is in D or R, the vehicle generally has power transmission, such as forward power transmission when the handle is in D, and backward power transmission when the handle is in R. Both situations are not empty. However, when the handle position is N (neutral position), the target power flow state is usually empty, but at this time the target speed ratio can be manually controlled to set, then the vehicle is not necessarily empty, that is, there is not necessarily no power transmission, so it cannot be determined that the vehicle has no power transmission based solely on the handle position being N.

[0075] As a possible implementation, if condition three is satisfied, S102 is executed. Condition three is to determine the transmission chain disengagement control based on the command current of the clutch. It should be noted that condition two is used to represent the driver's expectation, that is, it is determined based on the driver's control. However, even if the driver controls, the vehicle may not perform as expected by the driver due to errors or other reasons. In this case, it can be judged based on condition three, that is, the execution of the vehicle, so as to avoid misjudgment and improve the accuracy of the target speed ratio fault determination.

[0076] S103: If it is determined that the target speed ratio is faulty, control is performed to disengage the transmission chain to interrupt power transmission, and the target gear is updated to neutral.

[0077] For example, when it is determined that the target speed ratio fails, the high-side drive of the corresponding solenoid valve can be disconnected to control the disengagement of the transmission chain to interrupt the power transmission. For another example, the automatic transmission control unit controls the disengagement of the transmission chain to interrupt the power transmission request to control the disengagement of the transmission chain to interrupt the power transmission, and updates the target gear to neutral, for example, the automatic transmission control unit requests the target gear to be N (neutral) until the end of this driving cycle. Among them, one driving refers to the start of the driver starting the engine and the end of the engine shutting down.

[0078] It can be seen from the above technical solution that the current vehicle speed in the current gear is obtained. If the current vehicle speed is greater than or equal to the first vehicle speed threshold, the target speed ratio determined based on the current vehicle speed, or the speed ratio required to change from the current gear to the target gear, may cause the wheel speed to drag the engine or motor speed to above the maximum allowable speed due to the clutch engagement. At this time, the target speed ratio failure is determined. In order to ensure vehicle safety, if the target speed ratio failure is determined, the vehicle will not be controlled to shift to the target gear at the current speed, but the transmission chain will be controlled to be disengaged to interrupt the power transmission, and the target gear will be updated to neutral, so that the gearbox does not transmit power, or the input and output of the gearbox are disconnected, and the wheel speed will not drag the engine or motor speed to above the maximum allowable speed due to the clutch engagement, so that the engine or motor will not be damaged and cause a sudden lack of power output, thereby avoiding the vehicle from decelerating unexpectedly by the driver, thereby improving safety.

[0079] As a possible implementation method, in the related art, a vehicle equipped with an automatic transmission will perform gear shifting based on a gear shifting diagram, thereby changing the speed ratio of the vehicle. The gear shifting strategy in the related art is as follows:

[0080] (1) A shift map is obtained according to the shift pattern and the throttle, and then a target speed ratio of the shift map is obtained according to the shift map and the vehicle speed (for a continuously variable transmission (CVT)).

[0081] (2) An initial target speed ratio is obtained according to the position of the shift lever (such as the four gears of the vehicle, namely, parking gear, reverse gear, neutral gear and forward gear) and the target speed ratio of the shift map.

[0082] (3) Based on the initial target speed ratio, combined with other sources of target speed ratio requirements, such as disabling the limited speed ratio during fault post-processing, manually controlling the target speed ratio, and controlling the speed ratio that requires an intermediate transition, the target speed ratio required for the shift is obtained.

[0083] (4) The target speed ratio is checked. If updating the target speed ratio may cause the engine to overspeed, the target speed ratio is not updated and the previous speed ratio value is maintained.

[0084] (5) Perform speed ratio control based on the target speed ratio after successful verification.

[0085] (6) There is a timeout protection strategy for the speed ratio control. If the gear shift is not completed within the set time threshold, the current gear shift control will be exited and the clutch control will be opened to disengage the transmission chain and interrupt the power transmission, and the gear shift control will be restarted.

[0086] However, if the shift map is set unreasonably, the target gear of the shift map will be inappropriate. (4) Only the target gear to be updated is checked, that is, whether the updated target speed ratio will cause the engine to overspeed. If the target gear does not need to be updated according to the shift map, the target gear will remain unchanged. In other words, the previous target gear may also become inappropriate due to changes in vehicle conditions, which ultimately leads to an inappropriate target gear used for shifting.

[0087] Based on this, the embodiment of the present application limits the vehicle speed required for shifting gears. Specifically, the real-time vehicle speed and the second vehicle speed threshold corresponding to the current gear are obtained. If the real-time vehicle speed is equal to the second vehicle speed threshold, the target speed ratio is determined based on the second vehicle speed threshold, and the gear shifting operation is performed based on the target speed ratio.

[0088] The second vehicle speed threshold is determined based on the maximum allowable speed of the engine or motor and the engine speed rise margin. As a possible implementation, the second vehicle speed threshold can be determined by referring to formula (2):

[0089]

[0090] Among them, V1 is the second vehicle speed threshold, InputSpeedMax is the maximum allowable speed of the engine or motor, in rpm; Offset_1 is the engine speed increase margin, in rpm; i is the total speed ratio of the gearbox corresponding to the target speed ratio; R is the tire radius.

[0091] It should be noted that Offset_1 usually covers the margin of engine speed increase during normal gear shifting. As a possible implementation method, the higher the power requirements of the vehicle development goal, the smaller the corresponding Offset_1. During the gear shifting process, the vehicle will disengage one clutch and engage another clutch. In this process, the load will be reduced, so the engine speed will increase. The engine speed increase margin is the parameter to deal with this situation.

[0092] Therefore, the real-time vehicle speed can be limited based on the second vehicle speed threshold, thereby realizing the restriction of the gear shifting diagram, and limiting the vehicle speed corresponding to the upshifting point (such as the point corresponding to the shifting from 1st gear to 2nd gear) to below the second vehicle speed threshold, thereby preventing the unreasonable setting of the gear shifting diagram from causing an inappropriate target speed ratio.

[0093] In addition to the method for monitoring the speed ratio of a vehicle equipped with an automatic transmission, the embodiment of the present application also provides a device for monitoring the speed ratio of a vehicle equipped with an automatic transmission, such as Figure 2 As shown, it includes: an acquisition unit 201, a determination unit 202 and an execution unit 203;

[0094] The acquisition unit 201 is used to acquire the current vehicle speed during the gear shifting process based on the target speed ratio, wherein the target speed ratio is the speed ratio required to shift the current gear to the target gear;

[0095] The determining unit 202 is configured to determine a target speed ratio failure if the current vehicle speed is greater than or equal to a first vehicle speed threshold, wherein the first vehicle speed threshold is determined based on a maximum allowable speed of the engine or the motor;

[0096] The execution unit 203 is used for controlling the disengagement of the transmission chain to interrupt the power transmission and updating the target gear position to neutral if it is determined that the target speed ratio fails.

[0097] It can be seen from the above technical solution that the current vehicle speed in the current gear is obtained. If the current vehicle speed is greater than or equal to the first vehicle speed threshold, the target speed ratio determined based on the current vehicle speed, or the speed ratio required to change from the current gear to the target gear, may cause the wheel speed to drag the engine or motor speed to above the maximum allowable speed due to the clutch engagement. At this time, the target speed ratio failure is determined. In order to ensure vehicle safety, if the target speed ratio failure is determined, the vehicle will not be controlled to shift to the target gear at the current speed, but the transmission chain will be controlled to be disengaged to interrupt the power transmission, and the target gear will be updated to neutral, so that the gearbox does not transmit power, or the input and output of the gearbox are disconnected, and the wheel speed will not drag the engine or motor speed to above the maximum allowable speed due to the clutch engagement, so that the engine or motor will not be damaged and cause a sudden lack of power output, thereby avoiding the vehicle from decelerating unexpectedly by the driver, thereby improving safety.

[0098] As a possible implementation manner, the determining unit 202 is further configured to determine the first vehicle speed threshold. The first vehicle speed threshold is determined as follows:

[0099]

[0100] Among them, V2 is the first vehicle speed threshold, InputSpeedMax is the maximum allowable speed of the engine or the motor; Offset_2 is the deviation safety threshold corresponding to the target gear; i is the total speed ratio of the gearbox corresponding to the target speed ratio; R is the tire radius.

[0101] As a possible implementation manner, the obtaining unit 201 is further configured to:

[0102] Obtain handle position signal and vehicle speed signal;

[0103] The execution unit 203 is further configured to:

[0104] If the first and second conditions are met, the step of determining a target speed ratio failure if the current vehicle speed is greater than or equal to a first vehicle speed threshold is performed;

[0105] Among them, the first condition is that the handle position signal is valid and the vehicle speed signal is valid; the second condition is that the handle position signal indicates that the handle is in the forward position or the reverse position, or the vehicle has power transmission.

[0106] As a possible implementation manner, the execution unit 203 is further configured to:

[0107] During the current speed ratio control process corresponding to the current vehicle speed, if the transmission chain disengagement control is determined based on the command current of the clutch, the step of determining a target speed ratio failure if the current vehicle speed is greater than or equal to a first vehicle speed threshold is executed.

[0108] As a possible implementation manner, the obtaining unit 201 is further configured to:

[0109] In the process of shifting gears based on the target speed ratio, before obtaining the current vehicle speed, obtaining the real-time vehicle speed and a second vehicle speed threshold value corresponding to the current gear, wherein the second vehicle speed threshold value is determined based on the maximum allowable speed of the engine or the motor and the engine speed rise margin;

[0110] The execution unit 203 is further configured to:

[0111] If the real-time vehicle speed is equal to the second vehicle speed threshold, the target speed ratio is determined based on the second vehicle speed threshold, and a shift operation is performed based on the target speed ratio.

[0112] As a possible implementation manner, the determining unit 202 is further configured to determine the second vehicle speed threshold. The second vehicle speed threshold is determined as follows:

[0113]

[0114] Among them, V1 is the second vehicle speed threshold, InputSpeedMax is the maximum allowable speed of the engine or the motor; Offset_1 is the engine speed increase margin; i is the total speed ratio of the gearbox corresponding to the target speed ratio; and R is the tire radius.

[0115] The present application also provides a computer device, see Figure 3, which shows a structural diagram of a computer device provided in an embodiment of the present application, such as Figure 3 As shown, the device includes a memory 310 and a processor 320:

[0116] The memory 310 is used to store program codes and transmit the program codes to the processor;

[0117] The processor 320 is used to execute any of the speed ratio monitoring methods for a vehicle equipped with an automatic transmission provided in the above embodiments according to the instructions in the program code.

[0118] An embodiment of the present application provides a computer-readable storage medium, which is used to store a computer program, and the computer program is used to execute any one of the vehicle speed ratio monitoring methods equipped with an automatic transmission provided in the above embodiments.

[0119] The embodiment of the present application also provides a computer program product or a computer program, which includes computer instructions stored in a computer-readable storage medium. The processor of the computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the vehicle speed ratio monitoring method equipped with an automatic transmission provided in various optional implementations of the above aspects.

[0120] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the system or device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0121] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0122] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0123] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0124] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for monitoring the speed ratio of a vehicle equipped with an automatic transmission, characterized in that: The method comprises: In the process of shifting gears based on a target speed ratio, obtaining a current vehicle speed, wherein the target speed ratio is a speed ratio required to shift the current gear to the target gear; If the current vehicle speed is greater than or equal to a first vehicle speed threshold, determining that the target speed ratio is faulty, the first vehicle speed threshold being determined based on a maximum allowable speed of the engine or the motor; If it is determined that the target speed ratio fails, the transmission chain is disengaged to interrupt power transmission, and the target gear is updated to neutral.

2. The method according to claim 1, characterized in that The first vehicle speed threshold is determined as follows: Among them, V2 is the first vehicle speed threshold, InputSpeedMax is the maximum allowable speed of the engine or the motor; Offset_2 is the deviation safety threshold corresponding to the target gear; i is the total speed ratio of the gearbox corresponding to the target speed ratio; R is the tire radius.

3. The method according to claim 1, characterized in that The method further comprises: Obtain handle position signal and vehicle speed signal; If the first and second conditions are met, the step of determining a target speed ratio failure if the current vehicle speed is greater than or equal to a first vehicle speed threshold is performed; Among them, the first condition is that the handle position signal is valid and the vehicle speed signal is valid; the second condition is that the handle position signal indicates that the handle is in the forward position or the reverse position, or the vehicle has power transmission.

4. The method according to claim 3, characterized in that The method further comprises: During the current speed ratio control process corresponding to the current vehicle speed, if the transmission chain disengagement control is determined based on the command current of the clutch, the step of determining a target speed ratio failure if the current vehicle speed is greater than or equal to a first vehicle speed threshold is executed.

5. The method according to claim 1, characterized in that In the process of shifting gears based on the target speed ratio, before obtaining the current vehicle speed, the method further includes: Acquire the real-time vehicle speed and a second vehicle speed threshold corresponding to the current gear, wherein the second vehicle speed threshold is determined based on the maximum allowable speed of the engine or the motor and the engine speed surge margin; If the real-time vehicle speed is equal to the second vehicle speed threshold, the target speed ratio is determined based on the second vehicle speed threshold, and a shift operation is performed based on the target speed ratio.

6. The method according to claim 5, characterized in that The second vehicle speed threshold is determined as follows: Among them, V1 is the second vehicle speed threshold, InputSpeedMax is the maximum allowable speed of the engine or the motor; Offset_1 is the engine speed increase margin; i is the total speed ratio of the gearbox corresponding to the target speed ratio; and R is the tire radius.

7. A vehicle speed ratio monitoring device equipped with an automatic transmission, characterized in that: The device comprises: an acquisition unit, a determination unit and an execution unit; The acquisition unit is used to acquire the current vehicle speed during the gear shifting process based on the target speed ratio, wherein the target speed ratio is the speed ratio required to shift the current gear to the target gear; The determination unit is configured to determine a target speed ratio failure if the current vehicle speed is greater than or equal to a first vehicle speed threshold, wherein the first vehicle speed threshold is determined based on a maximum allowable speed of an engine or a motor; The execution unit is used for controlling the disengagement of the transmission chain to interrupt the power transmission and updating the target gear position to neutral if it is determined that the target speed ratio fails.

8. A computer device, characterized in that: The device comprises a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the method according to any one of claims 1 to 6 according to the instructions in the program code.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method according to any one of claims 1 to 6.

10. A computer program product, characterized in that The method comprises a computer program or an instruction; when the computer program or the instruction is executed by a processor, the method according to any one of claims 1 to 6 is executed.

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