Gearbox output shaft speed sensor failure diagnosis and control method and gearbox

Abstract

The present invention provides a diagnostic control method for a transmission output shaft speed sensor failure and a transmission. The method comprises: determining whether the transmission output shaft speed signal is below a low-speed threshold; if so, determining whether the transmission output shaft speed signal satisfies a rationality check initiation condition; and if so, initiating a rationality check of the transmission output shaft speed signal. Determining whether the transmission output shaft speed signal also satisfies an abnormality condition; if so, obtaining a processed value of the received transmission output shaft speed signal by a transmission controller and replacing the transmission output shaft speed signal with the processed value; and determining whether the transmission output shaft speed signal also satisfies a normal condition; if so, resuming reception of the transmission output shaft speed signal. By increasing the rationality check of the transmission output shaft speed sensor signal at low speeds, the coverage of the dual-clutch automatic transmission output shaft speed signal monitoring is improved, thereby increasing vehicle availability and enhancing performance.

Description

Technical Field

[0001] The present invention relates to the field of automobiles, and in particular to a diagnosis and control method for failure of a transmission output shaft speed sensor and a transmission. Background Art

[0002] The current method for managing the failure of the output shaft speed sensor of a dual-clutch automatic transmission has the following deficiencies:

[0003] The vehicle speed used by the automatic transmission control unit is derived from the transmission output shaft speed conversion. Upon detecting a failure of the transmission output shaft speed sensor, the transmission output shaft speed is replaced by another input source (drive wheel speed on the controller domain network or transmission input shaft speed hardwired into the controller). To protect the transmission, shifts from forward to reverse, or vice versa, are permitted only when the vehicle speed is below a threshold. The vehicle speed used by the automatic transmission control unit is derived from the transmission output shaft speed conversion. If the automatic transmission control unit uses an incorrect vehicle speed signal, the target gear position will be incorrect, resulting in poor performance. If the vehicle speed signal used in low-speed driving conditions is incorrect, it may also affect vehicle DR shifts, leading to power interruption.

[0004] The transmission output shaft speed sensor signal is one of the most important inputs in the automatic transmission control process, and it is very important to diagnose the transmission output speed sensor signal fault. Currently, there are two aspects to monitoring the transmission output shaft speed sensor signal:

[0005] One is an electrical fault related to the transmission output shaft speed sensor;

[0006] Second, when the speed reaches above a certain threshold, a three-axis rationality check is performed on the odd-numbered input shaft speed, even-numbered input shaft speed, and output shaft speed of the gearbox to detect faults in the gearbox output shaft speed sensor.

[0007] However, the above-mentioned monitoring of the transmission output shaft speed sensor signal only includes monitoring whether there is a fault but does not monitor whether there is an invalid signal. It has the disadvantage of insufficient robustness and there is a possibility of using an erroneous signal because the signal failure is not detected. Summary of the Invention

[0008] In order to solve the above technical problems, the purpose of the present invention is to provide a diagnosis and control method for failure of a transmission output shaft speed sensor, which increases the coverage of the dual-clutch automatic transmission output shaft speed signal monitoring by adding the rationality detection of the transmission output shaft speed sensor signal at low speed, thereby increasing the vehicle's availability and improving performance.

[0009] The present invention provides a method for diagnosing and controlling failure of a transmission output shaft speed sensor in this embodiment, including:

[0010] The gearbox output shaft speed signal rationality detection starting step determines whether the gearbox output shaft speed signal is lower than the low-speed threshold. If so, it determines whether the gearbox output shaft speed signal meets the rationality detection starting conditions. If the rationality detection starting conditions are met at the same time, the gearbox output shaft speed signal rationality detection is started.

[0011] The transmission output shaft speed signal rationality detection execution step determines whether the transmission output shaft speed signal satisfies abnormal conditions at the same time. If the abnormal conditions are met and last for a preset abnormal time threshold, the transmission obtains the processed value of the received transmission output shaft speed signal processed by the transmission controller and replaces the transmission output shaft speed signal.

[0012] The gearbox output shaft speed signal recovery step determines whether the gearbox output shaft speed signal satisfies normal conditions at the same time. If it satisfies and lasts for a preset normal time threshold, the gearbox recovers receiving the gearbox output shaft speed signal.

[0013] This solution adds rationality detection for abnormal transmission output shaft speed sensor signals at low speeds, improving the coverage of transmission output shaft speed signal monitoring. If an unreasonable transmission output shaft speed sensor signal is detected at low speeds, the transmission output shaft speed signal is replaced. This improves the coverage of dual-clutch automatic transmission output shaft speed signal monitoring and effectively avoids power interruptions caused by vehicle switching between drive-to-drive (DR) systems due to incorrect transmission output speeds at low speeds.

[0014] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a diagnostic control method for failure of a transmission output shaft speed sensor, wherein abnormal conditions include: a speed value converted from the input shaft speed to the output end is less than a preset first threshold; a transmission output shaft speed signal received by a transmission controller is zero; and a processed value of the transmission controller is greater than a second threshold and remains unchanged within an abnormal time threshold; and normal conditions include: a speed value converted from the input shaft speed to the output end is greater than a preset third threshold; and a transmission output shaft speed signal received by the transmission controller is greater than the second threshold; wherein the second threshold < the first threshold ≤ the third threshold.

[0015] By adopting the above scheme, it is possible to accurately determine that there is no circuit fault in the transmission output shaft speed sensor and no mechanical fault in the transmission. When power transmission occurs but the transmission output shaft speed signal is unreasonable, when the above abnormal conditions in this embodiment are met at the same time and last for more than the abnormal time threshold, it is determined that the transmission output shaft speed sensor signal drops to 0 abnormal fault and is replaced. When the above normal conditions are met at the same time and last for more than the normal time threshold, it is determined that the transmission output shaft speed signal drops to 0 abnormal recovery and the transmission output shaft speed sensor signal is restored. This can improve the coverage of the dual-clutch automatic transmission output shaft speed signal monitoring and effectively avoid the problem of power interruption caused by switching between vehicle DRs due to incorrect gear output speed at low speed.

[0016] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a method for diagnosing and controlling failure of a transmission output shaft speed sensor. The method for determining whether the speed value converted from the input shaft speed to the output end is less than a preset first threshold includes:

[0017] When the odd-numbered shaft shift fork is in position, the speed of the odd-numbered input shaft converted to the speed of the output end is less than the first threshold; or

[0018] When the even-numbered shaft shift fork is in position, the speed value of the even-numbered input shaft converted to the output end is less than the first threshold.

[0019] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a method for diagnosing and controlling failure of a transmission output shaft speed sensor, wherein a method for determining whether the speed value converted from the input shaft speed to the output end is greater than a preset third threshold value includes:

[0020] When the odd-numbered shaft shift fork is in position, the speed of the odd-numbered input shaft converted to the speed of the output end is greater than the third threshold; or

[0021] When the even-numbered shaft shift fork is in position, the speed value of the even-numbered input shaft converted to the output end is greater than the third threshold.

[0022] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a method for diagnosing and controlling failure of a transmission output shaft speed sensor. In the step of starting the rationality detection of the transmission output shaft speed signal, the rationality detection starting conditions include:

[0023] There is no electrical fault in the transmission output shaft speed sensor;

[0024] The transmission output shaft speed was determined to be fault-free after three-axis calibration;

[0025] The gearbox output shaft meets the detection enabling conditions;

[0026] The detection enabling conditions are that the transmission control system is powered on, the battery voltage is greater than the voltage threshold, the sensor is powered, and there is a transmission output shaft speed signal output.

[0027] The above solution can be used as an enabling condition for the rationality detection of the transmission output shaft speed signal, that is, the detection can be performed only when there is a signal output, while eliminating errors other than unreasonable transmission output shaft speed signals.

[0028] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a method for diagnosing and controlling failure of a transmission output shaft speed sensor. In the step of starting the transmission output shaft speed signal rationality detection, if the transmission output shaft speed signal is zero, a zero-drop signal correction is performed. The step of zero-drop signal correction is as follows:

[0029] If the transmission output shaft speed signal received by the transmission controller changes from a speed greater than a fourth threshold to zero, the processing value of the transmission controller remains at the value before the change to zero;

[0030] If the transmission output shaft speed signal received by the transmission controller changes from a speed less than the fourth threshold to zero, the processing value of the transmission controller gradually changes to zero according to the preset deceleration slope;

[0031] The second threshold value < the fourth threshold value < the first threshold value.

[0032] By adopting the above scheme, if an abnormality such as a sudden change in speed dropping to zero occurs before the rationality detection of the transmission output shaft speed signal, a processing value can be directly obtained and then the rationality detection of the transmission output shaft speed signal can be judged, so that in the rationality detection of the transmission output shaft speed signal, there is data to be analyzed regarding the judgment that "the processing value of the transmission controller is greater than the second threshold and remains unchanged within the abnormal time threshold range", thereby improving the analysis accuracy.

[0033] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a method for diagnosing and controlling failure of a transmission output shaft speed sensor, wherein if the transmission output shaft speed signal received by the transmission controller rises from zero to greater than a fifth threshold value, the processing value of the transmission controller changes from zero to the transmission output shaft speed signal; and

[0034] The fourth threshold value is less than the fifth threshold value.

[0035] With the above solution, when it is detected that the zero-drop anomaly does not reach the anomaly time threshold, the situation in which the transmission output shaft speed signal is indeed restored does not need to be replaced by a processed value.

[0036] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a diagnosis and control method for failure of a transmission output shaft speed sensor. In the transmission output shaft speed signal rationality detection starting step, if the transmission output shaft has an electrical fault, a three-axis calibration fault, or does not meet the detection enable conditions, the transmission obtains a processed value of the transmission controller to replace the transmission output shaft speed signal.

[0037] With the above solution, when a problem other than unreasonable signal is detected, that is, the above-mentioned types of faults, the system directly jumps to using the transmission to obtain the processing value of the transmission controller to replace the transmission output shaft speed signal.

[0038] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a diagnostic control method for failure of a transmission output shaft speed sensor, wherein the processing value of the transmission controller is the driving wheel speed obtained from the controller area network or the transmission input shaft speed input by the controller hard line.

[0039] By adopting the above solution, there is power transmission between the driving wheel or the input shaft and the output shaft of the gearbox, and the processing value can be converted relatively simply and accurately.

[0040] The present invention also provides a transmission, which is a dual-clutch automatic transmission, and the dual-clutch automatic transmission uses the above-mentioned transmission output shaft speed sensor failure diagnosis and control method when switching between forward gear and reverse gear.

[0041] The adoption of this management method can improve the coverage of the output shaft speed signal monitoring of the dual-clutch automatic transmission, and effectively avoid the problem of power interruption caused by incorrect transmission output speed at low speed.

[0042] The beneficial effects of the present invention are:

[0043] By providing a transmission output shaft speed sensor failure diagnosis and control method and transmission, the rationality detection of transmission output shaft speed sensor signal anomalies at low speeds is enhanced, thereby improving the coverage of transmission output shaft speed signal monitoring. If an unreasonable abnormality in the transmission output shaft speed sensor signal is detected at low speeds, the transmission output shaft speed signal is replaced. This improves the coverage of dual-clutch automatic transmission output shaft speed signal monitoring and effectively avoids power interruptions caused by vehicle switching between drive systems due to incorrect transmission output speeds at low speeds. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a control flow chart of a method for diagnosing and controlling failure of a transmission output shaft speed sensor in one implementation manner of Example 1 of the present invention;

[0045] Figure 2This is a control flow chart of a method for diagnosing and controlling failure of a transmission output shaft speed sensor in another implementation manner in Example 1 of the present invention. DETAILED DESCRIPTION

[0046] The following is an explanation of the embodiments of the present invention by specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this embodiment. On the contrary, the purpose of introducing the invention in conjunction with the embodiment is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will contain many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0047] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0048] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0049] The terms “first”, “second”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0050] In the description of this embodiment, it should be noted that, unless otherwise specified or limited, the terms "disposed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this embodiment based on specific circumstances.

[0051] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0052] Example 1

[0053] This embodiment provides a method for diagnosing and controlling failure of a transmission output shaft speed sensor. Figure 1 As shown, it includes a gearbox output shaft speed signal rationality detection starting step, a gearbox output shaft speed signal rationality detection execution step and a gearbox output shaft speed signal recovery step.

[0054] Among them, the step of starting the rationality detection of the transmission output shaft speed signal is to determine whether the transmission output shaft speed signal is lower than the low-speed threshold. If so, it is determined whether the transmission output shaft speed signal meets the rationality detection starting conditions. If the rationality detection starting conditions are met at the same time, the rationality detection of the transmission output shaft speed signal is started.

[0055] The execution steps of the rationality detection of the transmission output shaft speed signal are to determine whether the transmission output shaft speed signal meets the abnormal conditions at the same time. If the abnormal conditions are met and last for the preset abnormal time threshold, the transmission obtains the processed value of the transmission output shaft speed signal received by the transmission controller and replaces the transmission output shaft speed signal.

[0056] The gearbox output shaft speed signal recovery step is to determine whether the gearbox output shaft speed signal meets normal conditions at the same time. If it meets and lasts for a preset normal time threshold, the gearbox recovers to receive the gearbox output shaft speed signal.

[0057] Specifically, if the abnormal condition is met and continues for a preset abnormal time threshold, it means that an abnormality has occurred in the transmission output shaft speed signal at low speed. At this time, the transmission output shaft speed signal is replaced by the processed value. If the preset normal time threshold is met and continues, it means that the abnormality has been recovered and the transmission output shaft speed signal is resumed.

[0058] The low-speed threshold can be set by a person skilled in the art based on the speed threshold protection mechanism set when switching between forward and reverse gears of the existing transmission mentioned in the background technology, or it can be selected based on the actual vehicle model and manufacturing process accuracy. This embodiment does not make any specific limitations here.

[0059] Regarding the rationality detection starting conditions, they at least include the fault detection content already available in the prior art, so that rationality detection can be performed only when a signal is transmitted. If the rationality detection starting conditions are not met and an electrical or mechanical fault problem occurs, the processed value can be directly used as a substitute.

[0060] Abnormal conditions can be set according to the actual vehicle model and process level resulting in incorrect output speed. The preferred implementation will be described later and will not be repeated here. Similarly, the preferred normal conditions will be described later and will not be repeated here.

[0061] The preset abnormal time threshold can be determined based on existing vehicle self-diagnosis recovery times and empirically determined values for the time it takes for power to be interrupted due to an abnormal transmission output shaft speed signal for a specific vehicle model, and this embodiment does not impose any specific limitations on this. Similarly, those skilled in the art can determine the normal time threshold based on the accuracy and stability requirements of the actual output signal, and this embodiment does not impose any specific limitations on this normal time threshold.

[0062] The processed value of the transmission output shaft speed signal received by the transmission controller can be converted using input values from other input sources, such as the drive wheel speed or the drive axle at the end of the power transmission system obtained through theoretical calculation or empirical value conversion to the transmission output shaft speed.

[0063] This solution adds rationality detection for abnormal transmission output shaft speed sensor signals at low speeds, improving the coverage of transmission output shaft speed signal monitoring. If an unreasonable transmission output shaft speed sensor signal is detected at low speeds, the transmission output shaft speed signal is replaced. This improves the coverage of dual-clutch automatic transmission output shaft speed signal monitoring and effectively avoids power interruptions caused by vehicle switching between drive-to-drive (DR) systems due to incorrect transmission output speeds at low speeds.

[0064] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a diagnostic control method for failure of a transmission output shaft speed sensor, wherein abnormal conditions include: a speed value converted from the input shaft speed to the output end is less than a preset first threshold; a transmission output shaft speed signal received by a transmission controller is zero; and a processed value of the transmission controller is greater than a second threshold and remains unchanged within an abnormal time threshold; and normal conditions include: a speed value converted from the input shaft speed to the output end is greater than a preset third threshold; and a transmission output shaft speed signal received by the transmission controller is greater than the second threshold; wherein the second threshold < the first threshold ≤ the third threshold.

[0065] Specifically, the speed converted from the input shaft speed to the output end is the speed corresponding to the location where the transmission output shaft speed sensor is installed. Since the rationality check of the transmission output shaft speed signal is activated, other parameters are required to indirectly verify the transmission output shaft speed signal to determine whether the transmission output shaft speed signal is rational. In this embodiment, the rationality check is performed using the speed corresponding to the clutch input shaft output at the location where the transmission output shaft speed sensor is installed, the transmission output shaft speed signal received by the transmission controller, and the value processed by the transmission controller.

[0066] When the input shaft speed converted to the output speed value is less than the preset first threshold, it means that the vehicle is actually at low speed or stationary; when the processed value of the transmission controller is greater than the second threshold and remains unchanged within the abnormal time threshold range, it means that the output shaft speed processing value controlled by the transmission is abnormal, which is different from the input shaft reaction. This means that the moment the output shaft speed drops to zero is an abnormal situation, such as collecting the vehicle speed of the drive wheels on the controller domain network; and the transmission output shaft speed signal received by the transmission controller is zero, which means that although there is power transmission, the received transmission output shaft speed signal is zero, indicating that an output shaft drop-to-zero abnormality has occurred. In this case, the existing three-axis calibration can be activated to detect output speed faults. However, when the three-axis calibration time threshold is not met, the vehicle speed decreases and it is impossible to determine whether there is a significant vehicle speed (power transmission), so the output shaft speed sensor fault cannot be identified through the three-axis calibration. In this case, the output speed abnormality is determined by the method described in this patent. The fact that the received transmission output shaft speed signal remains unchanged after the abnormal time threshold indicates that the drop-to-zero abnormality is not an individual abnormal signal fluctuation, but rather an invalid signal.

[0067] The speed value converted from the input shaft speed to the output end is greater than the preset third threshold, and the transmission output shaft speed signal received by the transmission controller is greater than the second threshold, indicating that the signal has returned to normal.

[0068] The first threshold is the minimum threshold for performing a three-axis test. The vehicle has been moving, and above this speed, a three-axis test can be used to determine whether the output speed is abnormal.

[0069] The second threshold is used to handle the normal drop-to-zero output speed signal. Because the transmission's output speed is processed with resolution and accuracy by the TCU's underlying layer, the second threshold represents the resolution value received by the TCU's application layer. Below this threshold, the output shaft speed normally drops to zero. This is the minimum threshold.

[0070] The third threshold is the threshold for returning to normal after the low-speed output speed drops to 0 abnormally. It needs to cover the minimum threshold of the three-axis verification and ensure that the vehicle moves.

[0071] The fourth threshold is a threshold for determining whether the value drops to zero at low speed, and needs to be above the normal minimum threshold.

[0072] It should be understood that when the gearbox is a dual-clutch gearbox, the input shaft includes odd-numbered input shafts and / or even-numbered input shafts. When the gearbox is a single-clutch gearbox, the input shaft is one input shaft. Those skilled in the art can select the input shaft to be tested based on the specific vehicle model and needs. When it is a dual-clutch gearbox, they can choose to test one or both of them.

[0073] By adopting the above scheme, it is possible to accurately determine that there is no circuit fault in the transmission output shaft speed sensor and no mechanical fault in the transmission. When power transmission occurs but the transmission output shaft speed signal is unreasonable, when the above abnormal conditions in this embodiment are met at the same time and last for more than the abnormal time threshold, it is determined that the transmission output shaft speed sensor signal drops to 0 abnormal fault and is replaced. When the above normal conditions are met at the same time and last for more than the normal time threshold, it is determined that the transmission output shaft speed signal drops to 0 abnormal recovery and the transmission output shaft speed sensor signal is restored. This can improve the coverage of the dual-clutch automatic transmission output shaft speed signal monitoring and effectively avoid the problem of power interruption caused by switching between forward and reverse gears of the vehicle due to incorrect transmission output speed at low speed.

[0074] Furthermore, a method for determining whether the speed value converted from the input shaft speed to the output end is less than a preset first threshold value includes:

[0075] When the odd-numbered shaft shift fork is in position, the speed of the odd-numbered input shaft converted to the speed of the output end is less than the first threshold; or

[0076] When the even-numbered shaft shift fork is in position, the speed value of the even-numbered input shaft converted to the output end is less than the first threshold.

[0077] Specifically, when the odd-numbered shaft shift fork is in position or when the even-numbered shaft shift fork is in position, it indicates that the corresponding gear shift is completed and the clutch is transmitting power.

[0078] It's important to understand that the shift fork is a component of a car's transmission, connected to the shift handle and located at the bottom end. It shifts the middle shift wheel to change the input / output speed ratio. A dual-clutch transmission has two clutches and corresponding shift forks: one for the odd-numbered axles and one for the even-numbered axles.

[0079] Furthermore, a method for determining whether the speed value converted from the input shaft speed to the output end is greater than a preset third threshold value includes:

[0080] When the odd-numbered shaft shift fork is in position, the speed of the odd-numbered input shaft converted to the speed of the output end is greater than the third threshold; or

[0081] When the even-numbered shaft shift fork is in position, the speed value of the even-numbered input shaft converted to the output end is greater than the third threshold.

[0082] According to another specific embodiment of the present invention, a diagnosis and control method for a transmission output shaft speed sensor failure is disclosed in an embodiment of the present invention, such as Figure 2 As shown, in the step of starting the rationality detection of the transmission output shaft speed signal, the rationality detection starting conditions include:

[0083] There is no electrical fault in the transmission output shaft speed sensor;

[0084] The gearbox output shaft speed was verified to have no hardware faults after three-axis calibration;

[0085] The gearbox output shaft meets the detection enabling conditions;

[0086] The detection enabling conditions are that the transmission control system is powered on, the battery voltage is greater than the voltage threshold, the sensor is powered, and there is a transmission output shaft speed signal output.

[0087] Specifically, the transmission control system is powered on by the KL15 signal going high, and a normal battery voltage is indicated by the battery voltage being greater than a preset voltage threshold. If the battery voltage is too low, the automatic transmission electronic control system will not function properly, requiring the minimum voltage requirement for normal operation of the automatic transmission electronic control system to be met.

[0088] The above solution can be used as an enabling condition for the rationality detection of the transmission output shaft speed signal, that is, the detection can be performed only when there is a signal output, while eliminating errors other than unreasonable transmission output shaft speed signals.

[0089] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a method for diagnosing and controlling failure of a transmission output shaft speed sensor. In the step of starting the transmission output shaft speed signal rationality detection, if the transmission output shaft speed signal is zero, a zero-drop signal correction is performed. The step of zero-drop signal correction is as follows:

[0090] If the transmission output shaft speed signal received by the transmission controller changes from a speed greater than a fourth threshold to zero, the processing value of the transmission controller remains at the value before the change to zero;

[0091] If the transmission output shaft speed signal received by the transmission controller changes from a speed less than the fourth threshold to zero, the processing value of the transmission controller gradually changes to zero according to the preset deceleration slope;

[0092] The second threshold value < the fourth threshold value < the first threshold value.

[0093] By adopting the above scheme, if an abnormality such as a sudden change in speed dropping to zero occurs before the rationality detection of the transmission output shaft speed signal, a processing value can be directly obtained and then the rationality detection of the transmission output shaft speed signal can be judged, so that in the rationality detection of the transmission output shaft speed signal, there is data to be analyzed regarding the judgment that "the processing value of the transmission controller is greater than the second threshold and remains unchanged within the abnormal time threshold range", thereby improving the analysis accuracy.

[0094] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a method for diagnosing and controlling failure of a transmission output shaft speed sensor, wherein if the transmission output shaft speed signal received by the transmission controller rises from zero to greater than a fifth threshold value, the processing value of the transmission controller changes from zero to the transmission output shaft speed signal; and

[0095] The fourth threshold value is less than the fifth threshold value.

[0096] Specifically, if the output shaft speed returns to normal within the debounce time, there's no need to use the processed value as a replacement. Once the processed value is used as a replacement, the output shaft speed value can only be restored after normal conditions and time thresholds are met. The fourth threshold is less than the fifth threshold, and this setting is intended to ensure that the original transmission output shaft speed signal is restored.

[0097] With the above solution, when it is detected that the zero-drop anomaly does not reach the anomaly time threshold, the situation in which the transmission output shaft speed signal is indeed restored does not need to be replaced by a processed value.

[0098] According to another specific embodiment of the present invention, a diagnosis and control method for a transmission output shaft speed sensor failure is disclosed in an embodiment of the present invention, such as Figure 2 As shown, in the transmission output shaft speed signal rationality detection start step, if the transmission output shaft has an electrical fault, a three-axis calibration fault, or does not meet the detection enable, the transmission obtains the processing value of the transmission controller to replace the transmission output shaft speed signal.

[0099] With the above solution, when a problem other than unreasonable signal is detected, that is, the above-mentioned types of faults, the system directly jumps to using the transmission to obtain the processing value of the transmission controller to replace the transmission output shaft speed signal.

[0100] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a diagnostic control method for failure of a transmission output shaft speed sensor, wherein the processing value of the transmission controller is the driving wheel speed obtained from the controller area network or the transmission input shaft speed input by the controller hard line.

[0101] Specifically, the driving wheel is a wheel that is connected to the drive axle and then indirectly connected to the output shaft of the transmission. The ground friction force it receives is directed forward, providing driving force for the vehicle.

[0102] By adopting the above solution, there is power transmission between the driving wheel or the input shaft and the output shaft of the gearbox, and the processing value can be converted relatively simply and accurately.

[0103] Example 2

[0104] This embodiment provides a transmission, which is a dual-clutch automatic transmission. The dual-clutch automatic transmission uses the diagnosis and control method for failure of the transmission output shaft speed sensor in Example 1 when switching between forward gear and reverse gear.

[0105] The adoption of this management method can improve the coverage of the output shaft speed signal monitoring of the dual-clutch automatic transmission, and effectively avoid the problem of power interruption caused by incorrect transmission output speed at low speed.

[0106] Although the present invention has been illustrated and described with reference to certain preferred embodiments thereof, it should be understood by those skilled in the art that the above description is provided as a further detailed description of the present invention in conjunction with specific embodiments thereof, and that the specific implementation of the present invention is not limited to these descriptions. Those skilled in the art may make various changes in form and details, including simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A method for diagnosing and controlling a transmission output shaft speed sensor failure, comprising the following steps: a gearbox output shaft speed signal rationality detection initiation step, determining whether the gearbox output shaft speed signal is lower than a low-speed threshold; if so, determining whether the gearbox output shaft speed signal satisfies rationality detection initiation conditions; and if both conditions are satisfied, initiating the gearbox output shaft speed signal rationality detection; a gearbox output shaft speed signal rationality detection execution step, determining whether the gearbox output shaft speed signal satisfies an abnormal condition simultaneously; if the abnormal condition is satisfied and persists for a preset abnormal time threshold, the gearbox obtains a processed value of the gearbox output shaft speed signal received after the gearbox controller processes the received gearbox output shaft speed signal, and replaces the gearbox output shaft speed signal with the processed value; a gearbox output shaft speed signal recovery step, determining whether the gearbox output shaft speed signal satisfies normal conditions at the same time; if the normal conditions are met and last for a preset normal time threshold, the gearbox recovers receiving the gearbox output shaft speed signal; The abnormal conditions include: the speed value converted from the input shaft speed to the output end is less than a preset first threshold; the transmission output shaft speed signal received by the transmission controller is zero; and the processed value of the transmission controller is greater than a second threshold and remains unchanged within the abnormal time threshold range; The normal condition includes that the speed value converted from the input shaft speed to the output end is greater than the preset third threshold value, and the transmission output shaft speed signal received by the transmission controller is greater than the second threshold value; The second threshold < the first threshold ≤ the third threshold.

2. The method for diagnosing and controlling failure of a transmission output shaft speed sensor according to claim 1, characterized in that: The method for determining whether the speed value of the input shaft speed converted to the output end speed is less than a preset first threshold includes: When the odd-numbered shaft shift fork is in position, the speed of the odd-numbered input shaft converted to the speed of the output end is less than the first threshold; or When the even-numbered shaft shift fork is in position, the speed value of the even-numbered input shaft converted to the output end is less than the first threshold.

3. The method for diagnosing and controlling failure of a transmission output shaft speed sensor according to claim 1, characterized in that: The method for determining whether the speed value converted from the input shaft speed to the output end is greater than the preset third threshold value includes: When the odd-numbered shaft shift fork is in position, the speed of the odd-numbered input shaft converted to the speed of the output end is greater than the third threshold; or When the even-numbered shaft shift fork is in position, the speed value of the even-numbered input shaft converted to the output end is greater than the third threshold.

4. The method for diagnosing and controlling failure of a transmission output shaft speed sensor according to claim 1, characterized in that: In the step of starting the rationality detection of the transmission output shaft speed signal, the rationality detection starting conditions include: There is no electrical fault in the transmission output shaft speed sensor; The output shaft speed of the gearbox is judged to be fault-free after three-axis calibration; The gearbox output shaft meets the detection enabling conditions; wherein The detection enabling condition is that the transmission control system is powered on, the battery voltage is greater than the voltage threshold, the sensor is powered, and there is a transmission output shaft speed signal output.

5. The method for diagnosing and controlling failure of a transmission output shaft speed sensor according to claim 4, characterized in that: In the gearbox output shaft speed signal rationality detection starting step, if the gearbox output shaft speed signal is zero, a zero-drop signal correction is performed, and the zero-drop signal correction step is: If the transmission output shaft speed signal received by the transmission controller changes from a speed greater than a fourth threshold to zero, the processed value of the transmission controller remains at the value before the change to zero; If the transmission output shaft speed signal received by the transmission controller changes from a speed less than a fourth threshold to zero, the processing value of the transmission controller gradually changes to zero according to a preset deceleration slope; The second threshold < the fourth threshold < the first threshold.

6. The method for diagnosing and controlling failure of a transmission output shaft speed sensor according to claim 5, characterized in that: If the transmission output shaft speed signal received by the transmission controller increases from zero to greater than a fifth threshold, the processing value of the transmission controller changes from zero to the transmission output shaft speed signal; and The fourth threshold value is less than the fifth threshold value.

7. The method for diagnosing and controlling failure of a transmission output shaft speed sensor according to claim 4, characterized in that: In the transmission output shaft speed signal rationality detection starting step, if the transmission output shaft has the electrical fault, the three-axis calibration fault or does not meet the detection enabling conditions, the transmission obtains the processed value of the transmission controller to replace the transmission output shaft speed signal.

8. The method for diagnosing and controlling failure of a transmission output shaft speed sensor according to claim 1, characterized in that: The processing value of the transmission controller is the driving wheel speed obtained from the controller area network or the transmission input shaft speed input by the controller hard line.

9. A gearbox, characterized in that: The transmission is a dual-clutch automatic transmission, and the dual-clutch automatic transmission uses the transmission output shaft speed sensor failure diagnosis and control method according to any one of claims 1 to 8 when switching between forward gear and reverse gear.

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