A method of fault determination based on a continuously variable transmission and related apparatus

Abstract

The application discloses a fault determination method based on a continuously variable transmission and a related device. The method comprises the following steps: when it is detected that the average rotation speed of a driving wheel and the actual rotation speed of a driven wheel do not match for a first preset time period, a first converted rotation speed is converted according to the actual rotation speed of a driving wheel and a first transmission relationship between the driving wheel and the driven wheel, and a second converted rotation speed is converted according to the average rotation speed of the driving wheel and a second transmission relationship between the driven wheel and the driving wheel; the first converted rotation speed, the actual rotation speed of the driven wheel and the second converted rotation speed are cross-verified to obtain a verification result; when the verification result indicates that the first converted rotation speed and the second converted rotation speed match, and the first converted rotation speed and the second converted rotation speed both do not match the actual rotation speed of the driven wheel, it is determined that the driven wheel has a fault; and when the verification result indicates that the first converted rotation speed and the actual rotation speed of the driven wheel match, and the first converted rotation speed and the actual rotation speed of the driven wheel both do not match the second converted rotation speed, it is determined that the driving wheel has a fault.

Description

Technical Field

[0001] This application relates to the field of data analysis technology, and in particular to a fault determination method and related apparatus based on continuously variable transmissions (CVTs). Background Technology

[0002] Currently, in vehicle power transmission based on continuously variable transmissions (CVTs), the speed ratio between the driving wheel and the driven wheel is changed by the clamping force of the steel belt. The driven wheel drives the drive wheel to rotate through the transmission device. There is a certain transmission relationship between the speed of the driving wheel, the speed of the driven wheel, and the average speed of the drive wheel.

[0003] In the prior art, when a mismatch is detected between the average speed of the drive wheel and the actual speed of the driven wheel for a certain period of time, it is determined that the driven wheel has malfunctioned. The actual speed of the driven wheel is replaced by the speed calculated from the average speed of the drive wheel based on the transmission relationship between the driven wheel and the drive wheel.

[0004] However, research has revealed that even when the drive wheels malfunction, there can be a mismatch between the average speed of the drive wheels and the actual speed of the driven wheels over a certain period of time. Using the above method to mistakenly identify a malfunction in the driven wheels leads to an incorrect fault diagnosis, causing the actual speed of the driven wheels to be incorrectly replaced, resulting in abnormal power transmission in the vehicle and thus posing a power safety risk during vehicle operation. Summary of the Invention

[0005] In view of this, embodiments of this application provide a fault determination method and related apparatus based on a continuously variable transmission (CVT), which distinguishes between faults in the driven wheel and faults in the drive wheel, and obtains accurate fault diagnosis results; so that subsequent correct fault handling can be carried out based on the fault diagnosis results, thereby avoiding power safety risks during vehicle operation.

[0006] In a first aspect, embodiments of this application provide a fault determination method based on a continuously variable transmission (CVT), the method comprising:

[0007] If the average speed of the drive wheel and the actual speed of the driven wheel are not matched within a first preset time period, the average speed of the drive wheel and the actual speed of the driven wheel are converted according to the first transmission relationship between the drive wheel and the driven wheel, the average speed of the drive wheel and the second transmission relationship between the driven wheel and the drive wheel, to obtain the first converted speed after converting the actual speed of the drive wheel and the second converted speed after converting the average speed of the drive wheel.

[0008] Cross-validation is performed on the first converted speed, the actual speed of the driven wheel, and the second converted speed to obtain the validation result;

[0009] If the verification result indicates that the second converted speed matches the first converted speed, and neither the first converted speed nor the second converted speed matches the actual speed of the driven wheel, then it is determined that the driven wheel has malfunctioned.

[0010] If the verification result indicates that the actual speed of the driven wheel matches the first calculated speed, and neither the first calculated speed nor the actual speed of the driven wheel matches the second calculated speed, then the drive wheel is determined to be faulty.

[0011] Optionally, the step of converting the actual speed of the driving wheel, the first transmission relationship between the driving wheel and the driven wheel, the average speed of the driving wheel, and the second transmission relationship between the driven wheel and the driving wheel to obtain the first converted speed after converting the actual speed of the driving wheel and the second converted speed after converting the average speed of the driving wheel includes:

[0012] If the average speed of the drive wheel and the actual speed of the driven wheel are not matched within a second preset time period, open-loop control of the target speed ratio is requested to maintain the target speed ratio; the second preset time period is shorter than the first preset time period, and the target speed ratio is the ratio of the target speed of the drive wheel to the filtered speed of the driven wheel;

[0013] When it is detected that the average speed of the drive wheel and the actual speed of the driven wheel do not match within the first preset time period, the first converted speed and the second converted speed are obtained by conversion based on the actual speed of the drive wheel, the first transmission relationship, the average speed of the drive wheel and the second transmission relationship.

[0014] Optionally, the matching of the first converted speed and the second converted speed specifically means that the difference between the first converted speed and the second converted speed conforms to a preset difference range; the mismatch between the first converted speed and the second converted speed and the actual speed of the driven wheel includes the difference between the first converted speed and the actual speed of the driven wheel not conforming to the preset difference range, and the difference between the second converted speed and the actual speed of the driven wheel not conforming to the preset difference range.

[0015] Optionally, the matching of the first converted speed and the actual speed of the driven wheel specifically means that the difference between the first converted speed and the actual speed of the driven wheel conforms to a preset difference range; the mismatch between the first converted speed and the actual speed of the driven wheel and the second converted speed includes the difference between the first converted speed and the second converted speed not conforming to the preset difference range, and the difference between the actual speed of the driven wheel and the second converted speed not conforming to the preset difference range.

[0016] Optionally, after determining that the driven wheel has failed, the method further includes:

[0017] The second converted speed is used to replace the actual speed of the driven wheel.

[0018] Optionally, after determining that the driven wheel has failed, the method further includes:

[0019] Record the failure of the driven wheel and disable the functions related to using the actual speed of the driven wheel.

[0020] Optionally, after determining that the drive wheel has failed, the method further includes:

[0021] Based on the actual rotational speed of the driven wheel and the second transmission relationship, a third converted rotational speed is obtained after converting the actual rotational speed of the driven wheel;

[0022] The third converted speed is used instead of the average speed of the drive wheel.

[0023] Optionally, after determining that the drive wheel has failed, the method further includes:

[0024] Record the failure of the drive wheel and disable the function related to using the average speed of the drive wheel.

[0025] Secondly, embodiments of this application provide a fault determination device based on a continuously variable transmission (CVT), the device comprising: a conversion unit, a verification unit, and a determination unit;

[0026] The conversion unit is used to perform a conversion based on the actual speed of the driving wheel, the first transmission relationship between the driving wheel and the driven wheel, and the second transmission relationship between the driving wheel and the driven wheel if a mismatch between the average speed of the driving wheel and the actual speed of the driven wheel is detected within a first preset time period, so as to obtain a first converted speed after the conversion of the actual speed of the driving wheel and a second converted speed after the conversion of the average speed of the driving wheel.

[0027] The verification unit is used to perform cross-verification on the first converted speed, the actual speed of the driven wheel, and the second converted speed to obtain a verification result;

[0028] The determining unit is configured to determine that the driven wheel has malfunctioned if the verification result indicates that the second converted speed and the first converted speed match, and both the first converted speed and the second converted speed do not match the actual speed of the driven wheel;

[0029] The determining unit is further configured to determine that the drive wheel has malfunctioned if the verification result indicates that the actual rotational speed of the driven wheel matches the first converted rotational speed, and neither the first converted rotational speed nor the actual rotational speed of the driven wheel matches the second converted rotational speed.

[0030] Thirdly, embodiments of this application provide a computer device, the computer device including a processor and a memory:

[0031] The memory is used to store program code and transmit the program code to the processor;

[0032] The processor is used to execute the fault determination method based on the continuously variable transmission described in the first aspect according to the instructions in the program code.

[0033] Compared with the prior art, this application has at least the following advantages:

[0034] Using the technical solution of this application embodiment, when a mismatch is detected between the average speed of the driving wheel and the actual speed of the driven wheel within a first preset time period, the actual speed of the driving wheel is converted into a first converted speed according to the first transmission relationship between the driving wheel and the driven wheel, and the average speed of the driving wheel is converted into a second converted speed according to the second transmission relationship between the driven wheel and the driving wheel. A cross-verification is performed on the first converted speed, the actual speed of the driven wheel, and the second converted speed to obtain a verification result. If the verification result indicates that the first converted speed and the second converted speed match, and both the first converted speed and the second converted speed do not match the actual speed of the driven wheel, then a fault is determined to have occurred in the driven wheel. If the verification result indicates that the first converted speed and the actual speed of the driven wheel match, and both the first converted speed and the actual speed of the driven wheel do not match the second converted speed, then a fault is determined to have occurred in the driving wheel.

[0035] As can be seen, when the average speed of the driving wheel and the actual speed of the driven wheel do not match within the first preset time period, based on the second converted speed obtained by converting the average speed of the driving wheel and the second transmission relationship between the driven wheel and the driving wheel, the first converted speed obtained by converting the actual speed of the driving wheel and the first transmission relationship between the driving wheel and the driven wheel is further used, combined with the cross-verification of the actual speed of the driven wheel, to distinguish between a fault in the driven wheel and a fault in the driving wheel, thus obtaining an accurate fault diagnosis result; so that the correct fault handling can be carried out based on the fault diagnosis result, thereby avoiding power safety risks during vehicle operation. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments of this application or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of vehicle power transmission based on a continuously variable transmission (CVT).

[0038] Figure 2 This is a schematic diagram of a method for diagnosing and handling a driven wheel failure in the prior art;

[0039] Figure 3 This is a schematic diagram of a prior art method for diagnosing and handling drive wheel failures;

[0040] Figure 4 This is a schematic diagram of the system framework involved in one application scenario in the embodiments of this application;

[0041] Figure 5 A flowchart illustrating a fault determination method based on a continuously variable transmission (CVT) provided in this application embodiment;

[0042] Figure 6 A schematic diagram illustrating a method for diagnosing and handling a driven wheel malfunction, provided in an embodiment of this application;

[0043] Figure 7 A schematic diagram illustrating a method for diagnosing and handling drive wheel failures provided in an embodiment of this application;

[0044] Figure 8 This is a schematic diagram of a fault determination device based on a continuously variable transmission (CVT) provided in an embodiment of this application. Detailed Implementation

[0045] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0046] At present, see Figure 1 The diagram illustrates a vehicle power transmission system based on a continuously variable transmission (CVT). The speed ratio between the driving and driven wheels is altered by the clamping force of a steel belt. The driven wheel drives the driving wheel to rotate via a transmission device. A specific transmission relationship exists between the speeds of the driving wheel, the driven wheel, and the average speed of the driving wheel. In existing technology, when a mismatch between the average speed of the driving wheel and the actual speed of the driven wheel is detected for a certain period, a fault is determined in the driven wheel. The actual speed of the driven wheel is then replaced by a speed calculated from the average speed of the driving wheel, based on the transmission relationship between the driven and driving wheels.

[0047] See Figure 2The diagram illustrates a prior art method for diagnosing and handling a driven wheel malfunction. At time t1, a mismatch is detected between the average speed of the driving wheel and the actual speed of the driven wheel. At time t2, this mismatch is confirmed to have occurred within a certain time period, indicating a driven wheel malfunction. At time t3, the actual speed of the driven wheel is replaced by the speed calculated from the average speed of the driving wheel, based on the transmission relationship between the driven wheel and the driving wheel. The replaced driven wheel speed is shown in the figure.

[0048] However, research has revealed that even when the drive wheel malfunctions, there can be a mismatch between the average speed of the drive wheel and the actual speed of the driven wheel over a certain period of time. (See [reference needed]). Figure 3 The diagram illustrates a prior art method for diagnosing and handling drive wheel failures. At time t1, a mismatch is detected between the average speed of the drive wheel and the actual speed of the driven wheel. At time t2, this mismatch leads to a misinterpretation of a driven wheel failure over a certain period. At time t3, the actual driven wheel speed is replaced by a speed calculated from the average speed of the drive wheel, based on the transmission relationship between the driven and drive wheels. The replaced driven wheel speed is shown in the diagram. This method incorrectly identifies faults in both the driven and drive wheels, leading to an incorrect replacement of the actual driven wheel speed with an abnormal power transmission, thus posing a power safety risk during vehicle operation.

[0049] To address this issue, in this embodiment, when a mismatch between the average speed of the driving wheel and the actual speed of the driven wheel is detected within a first preset time period, the actual speed of the driving wheel is converted into a first converted speed according to the first transmission relationship between the driving wheel and the driven wheel, and the average speed of the driving wheel is converted into a second converted speed according to the second transmission relationship between the driven wheel and the driving wheel. A cross-verification is performed on the first converted speed, the actual speed of the driven wheel, and the second converted speed to obtain a verification result. If the verification result indicates that the first converted speed and the second converted speed match, and both the first converted speed and the second converted speed do not match the actual speed of the driven wheel, then a fault is determined to have occurred in the driven wheel. If the verification result indicates that the first converted speed and the actual speed of the driven wheel match, and both the first converted speed and the actual speed of the driven wheel do not match the second converted speed, then a fault is determined to have occurred in the driving wheel.

[0050] As can be seen, when the average speed of the driving wheel and the actual speed of the driven wheel do not match within the first preset time period, based on the second converted speed obtained by converting the average speed of the driving wheel and the second transmission relationship between the driven wheel and the driving wheel, the first converted speed obtained by converting the actual speed of the driving wheel and the first transmission relationship between the driving wheel and the driven wheel is further used, combined with the cross-verification of the actual speed of the driven wheel, to distinguish between a fault in the driven wheel and a fault in the driving wheel, thus obtaining an accurate fault diagnosis result; so that the correct fault handling can be carried out based on the fault diagnosis result, thereby avoiding power safety risks during vehicle operation.

[0051] For example, one scenario in the embodiments of this application can be applied to, such as Figure 4 The scenario shown includes an Electronic Control Unit (ECU) 401, a drive wheel speed sensor 402, a driven wheel speed sensor 403, and a drive wheel speed sensor 404. The drive wheel speed sensor 402 detects the actual speed of the drive wheel and transmits it to the ECU 401. The driven wheel speed sensor 403 detects the actual speed of the driven wheel and transmits it to the ECU 401. The drive wheel speed sensor 404 detects the average speed of the drive wheel and transmits it to the ECU 401. The ECU 401 uses the implementation method of the continuously variable transmission (CVT) fault determination method provided in this application embodiment to distinguish between faults in the driven wheel and faults in the drive wheel, thereby obtaining accurate fault diagnosis results.

[0052] First, in the above application scenarios, although the action description of the implementation method provided in this application is executed by ECU401, the implementation method of this application is not limited in terms of the execution subject, as long as the action disclosed in the implementation method provided in this application is executed.

[0053] Secondly, the above scenario is only one example provided by the embodiments of this application, and the embodiments of this application are not limited to this scenario.

[0054] The following detailed description, in conjunction with the accompanying drawings, illustrates the specific implementation of the fault determination method and related devices based on continuously variable transmissions (CVTs) in this application.

[0055] First, the specific implementation of the fault determination method based on a continuously variable transmission (CVT) in this application will be explained in detail through examples.

[0056] See Figure 5 This document illustrates a flowchart of a fault determination method based on a continuously variable transmission (CVT) according to an embodiment of this application. In this embodiment, the method may include, for example, the following steps:

[0057] Step 501: If the average speed of the drive wheel and the actual speed of the driven wheel are not matched within a first preset time period, the average speed of the drive wheel and the actual speed of the driven wheel are converted according to the first transmission relationship between the drive wheel and the driven wheel, the average speed of the drive wheel and the second transmission relationship between the driven wheel and the drive wheel, to obtain the first converted speed after converting the actual speed of the drive wheel and the second converted speed after converting the average speed of the drive wheel.

[0058] In existing technology, when a mismatch between the average speed of the driving wheel and the actual speed of the driven wheel is detected for a certain period of time, a fault is determined in the driven wheel. The actual speed of the driven wheel is then replaced by the speed calculated from the average speed of the driving wheel, based on the transmission relationship between the driven and driving wheels. However, research has revealed that even when the driving wheel malfunctions, the mismatch between the average speed of the driving wheel and the actual speed of the driven wheel can still occur for a certain period. Using the above method to mistakenly identify a fault in the driven wheel leads to an incorrect fault diagnosis, resulting in the incorrect replacement of the actual speed of the driven wheel with an abnormal power transmission, thus posing a power safety risk during vehicle operation.

[0059] Therefore, in this embodiment, when a mismatch between the average speed of the driving wheel and the actual speed of the driven wheel is detected for a certain period of time, i.e., when a mismatch between the average speed of the driving wheel and the actual speed of the driven wheel is detected for a first preset period of time, it is not directly determined that the driven wheel has failed. Instead, based on the certain transmission relationship between the speed of the driving wheel, the speed of the driven wheel, and the average speed of the driving wheel, the actual speed of the driving wheel is converted into a first converted speed according to the first transmission relationship between the driving wheel and the driven wheel, and the average speed of the driving wheel is converted into a second converted speed according to the second transmission relationship between the driven wheel and the driving wheel. This allows for a more accurate determination of whether the driven wheel or the driving wheel has failed, based on the first converted speed, the actual speed of the driven wheel, and the second converted speed.

[0060] In the specific implementation of step 501, when it is detected that the average speed of the driving wheel and the actual speed of the driven wheel do not match within a second preset time period that is less than the first preset time period, in order to maintain the target speed ratio (the speed ratio between the active target speed and the driven wheel filter speed), it is necessary to request open-loop control of the target speed ratio. Based on this, when it is further detected that the average speed of the driving wheel and the actual speed of the driven wheel do not match within the first preset time period, the actual speed of the driving wheel can be converted into a first converted speed according to the first transmission relationship between the driving wheel and the driven wheel, and the average speed of the driving wheel can be converted into a second converted speed according to the second transmission relationship between the driven wheel and the driving wheel. Therefore, in an optional embodiment of this application, step 501 may include, for example, the following steps 5011-5012:

[0061] Step 5011: If it is detected that the average speed of the drive wheel and the actual speed of the driven wheel do not match within a second preset time period, request open-loop control of the target speed ratio to maintain the target speed ratio; the second preset time period is shorter than the first preset time period, and the target speed ratio is the speed ratio of the target speed of the drive wheel to the filtered speed of the driven wheel.

[0062] Step 5012: When it is detected that the average speed of the drive wheel and the actual speed of the driven wheel do not match within the first preset time period, the first converted speed and the second converted speed are obtained by conversion based on the actual speed of the drive wheel, the first transmission relationship, the average speed of the drive wheel and the second transmission relationship.

[0063] Step 502: Perform cross-verification on the first converted speed, the actual speed of the driven wheel, and the second converted speed to obtain the verification result.

[0064] In this embodiment of the application, after obtaining the first converted speed and the second converted speed in step 501, since the first converted speed is obtained by converting the actual speed of the driving wheel according to the first transmission relationship between the driving wheel and the driven wheel, and the second converted speed is obtained by converting the average speed of the driving wheel according to the second transmission relationship between the driven wheel and the driving wheel, in the event of a failure of the driven wheel or the driving wheel, only one of the first converted speed, the actual speed of the driven wheel, and the second converted speed matches the first converted speed, and neither the first converted speed nor the aforementioned speed matches the other speed; based on this, the first converted speed, the actual speed of the driven wheel, and the second converted speed can be cross-checked to obtain a check result, and the check result can be used to further accurately determine whether the failure is caused by the driven wheel or the driving wheel.

[0065] Step 503: If the verification result indicates that the second converted speed matches the first converted speed, and neither the first converted speed nor the second converted speed matches the actual speed of the driven wheel, then it is determined that the driven wheel has malfunctioned.

[0066] In this embodiment of the application, after obtaining the verification result by executing step 502, if the verification result is specifically the first converted speed, the actual speed of the driven wheel, and the second converted speed, and the second converted speed matches the first converted speed but neither the first converted speed nor the second converted speed matches the actual speed of the driven wheel, it indicates that the average speed of the drive wheel is correct but the actual speed of the driven wheel is incorrect, and therefore it is determined that the driven wheel has malfunctioned.

[0067] In this context, "matching" means that the difference between the two rotational speeds falls within a preset range, while "mismatching" means that the difference between the two rotational speeds does not fall within the preset range. Therefore, in an optional embodiment of this application, "matching" the first converted rotational speed and the second converted rotational speed specifically means that the difference between the first converted rotational speed and the second converted rotational speed falls within a preset range; "mismatching" the first converted rotational speed and the second converted rotational speed with respect to the actual rotational speed of the driven wheel includes situations where the difference between the first converted rotational speed and the actual rotational speed of the driven wheel does not fall within the preset range, and the difference between the second converted rotational speed and the actual rotational speed of the driven wheel does not fall within the preset range.

[0068] Furthermore, in this embodiment, after determining that the driven wheel has malfunctioned in step 503, in order to correct the incorrect actual speed of the driven wheel, it is necessary to replace the actual speed of the driven wheel with a second converted speed obtained by converting the average speed of the driving wheel according to the second transmission relationship between the driven wheel and the driving wheel. Therefore, in an optional embodiment of this application, after step 503, the method may further include step A: replacing the actual speed of the driven wheel with the second converted speed.

[0069] Furthermore, in this embodiment of the application, after determining that the driven wheel has malfunctioned in step 503, in order to facilitate subsequent identification of the driven wheel malfunction and avoid abnormalities in functions related to the actual rotational speed of the driven wheel, it is necessary to record the driven wheel malfunction and disable the functions related to the actual rotational speed of the driven wheel. Therefore, in an optional embodiment of this application, after step 503, the method may further include step B: recording the driven wheel malfunction and disabling the functions related to the actual rotational speed of the driven wheel.

[0070] As an example, such as Figure 6 The diagram illustrates a method for diagnosing and handling a driven wheel malfunction according to an embodiment of this application. During the 0-t1 stage, the vehicle is in normal operation. The actual speed ratio (the ratio of the actual speed of the driving wheel to the speed of the driven wheel after substitution) follows the target speed ratio. There is a certain transmission relationship between the driving wheel speed, the driven wheel speed, and the average speed of the driving wheels. At time t1, a driven wheel malfunction occurs, causing a step drop in the actual speed of the driven wheel, increasing the actual speed ratio. The target speed ratio increases slightly under the action of the filtering module, while the average speed of the driving wheels remains unchanged. At this time, a large deviation occurs between the actual speed ratio and the target speed ratio. To ensure that the actual speed ratio can follow the change in the target speed ratio, the driving wheel speed is gradually decreased. During the t1-t2 stage, a mismatch between the average speed of the driving wheels and the actual speed of the driven wheels is detected. At time t2, if the mismatch between the average speed of the driving wheels and the actual speed of the driven wheels conforms to a second preset time period (the time period t1-t2), open-loop control of the target speed ratio is requested. The actual speed ratio value is replaced by the target speed ratio value to maintain the target speed ratio at time t2.

[0071] During the t2-t3 phase, a mismatch between the average speed of the driving wheel and the actual speed of the driven wheel is detected. At time t3, the mismatch between the average speed of the driving wheel and the actual speed of the driven wheel is detected to be within the first preset time period (the time period t1-t3). During the t3-t4 phase, a cross-validation is performed on the first converted speed (obtained by converting the actual speed of the driving wheel according to the first transmission relationship between the driving wheel and the driven wheel), the actual speed of the driven wheel, and the second converted speed (obtained by converting the average speed of the driving wheel according to the second transmission relationship between the driven wheel and the driving wheel). If the second converted speed matches the first converted speed, and if both the first converted speed and the second converted speed do not match the actual speed of the driven wheel, it is determined that the driven wheel has failed. At time t4, the second converted speed is used to replace the actual speed of the driven wheel, and the speed of the driven wheel after replacement is shown in the figure. During the t4-t5 stage, under the action of the filter module, the filtered speed of the driven wheel slowly changes to the speed of the driven wheel after replacement. At this time, the target speed ratio is still in open-loop control. The flag bit of the driven wheel failure is returned to record the failure of the driven wheel and the relevant functions of using the actual speed of the driven wheel are turned off.

[0072] At time t5, the open-loop control of the target speed ratio is exited; during the t5-t6 stage, as the speed of the driven wheel filter gradually follows the speed of the replaced driven wheel, the target speed ratio gradually decreases to the value at time t1, and the actual speed ratio gradually changes synchronously with the target speed ratio.

[0073] Step 504: If the verification result indicates that the actual speed of the driven wheel matches the first converted speed, and neither the first converted speed nor the actual speed of the driven wheel matches the second converted speed, then it is determined that the drive wheel has malfunctioned.

[0074] In this embodiment of the application, after obtaining the verification result by executing step 502, if the verification result is specifically the first converted speed, the actual speed of the driven wheel, and the second converted speed, and the actual speed of the driven wheel matches the first converted speed, but neither the first converted speed nor the actual speed of the driven wheel matches the second converted speed, it indicates that the actual speed of the driven wheel is correct while the average speed of the drive wheel is incorrect, and therefore it is determined that the drive wheel has malfunctioned.

[0075] Similarly, in an optional embodiment of this application, the matching of the first converted speed and the actual speed of the driven wheel specifically means that the difference between the first converted speed and the actual speed of the driven wheel meets a preset difference range; the mismatch between the first converted speed and the actual speed of the driven wheel and the second converted speed includes the difference between the first converted speed and the second converted speed not meeting the preset difference range, and the difference between the actual speed of the driven wheel and the second converted speed not meeting the preset difference range.

[0076] Furthermore, in this embodiment of the application, after determining that the drive wheel has malfunctioned in step 504, in order to correct the incorrect average speed of the drive wheel, it is necessary to convert the correct actual speed of the driven wheel into a third converted speed according to the second transmission relationship between the driven wheel and the drive wheel, and then replace the average speed of the drive wheel with the third converted speed. Therefore, in an optional embodiment of this application, after step 504, the method may further include, for example, the following steps C-D:

[0077] Step C: Based on the actual speed of the driven wheel and the second transmission relationship, a third converted speed is obtained after converting the actual speed of the driven wheel.

[0078] Step D: Use the third converted speed instead of the average speed of the drive wheel.

[0079] Furthermore, in this embodiment of the application, after determining that the drive wheel has malfunctioned in step 503, in order to facilitate subsequent identification of the drive wheel malfunction and avoid abnormalities in the functions related to the average speed of the drive wheel, it is necessary to record the drive wheel malfunction and disable the functions related to the average speed of the drive wheel. Therefore, in an optional embodiment of this application, after step 504, the method may further include step E: recording the drive wheel malfunction and disabling the functions related to the average speed of the drive wheel.

[0080] As an example, such as Figure 7 The diagram shown illustrates a method for diagnosing and handling a driven wheel malfunction according to an embodiment of this application. During the 0-t1 phase, the vehicle is in normal operation. The actual speed ratio (the ratio of the actual speed of the driving wheel to the speed of the replaced driven wheel) follows the target speed ratio. There is a certain transmission relationship between the driving wheel speed, the driven wheel speed, and the average speed of the driving wheel. At time t1, a drive wheel malfunction occurs, causing a step drop in the average speed of the driving wheel. The target speed ratio and the actual speed ratio remain unchanged. During the t1-t2 phase, a mismatch is detected between the average speed of the driving wheel and the actual speed of the driven wheel. At time t2, the mismatch is detected to conform to a second preset time period (the time period t1-t2). Open-loop control of the target speed ratio is requested, and the actual speed ratio value is replaced by the target speed ratio value to maintain the target speed ratio at time t2.

[0081] During the t2-t3 phase, a mismatch between the average speed of the drive wheel and the actual speed of the driven wheel continues to be detected. At time t3, the mismatch between the average speed of the drive wheel and the actual speed of the driven wheel is detected to be within the first preset time period (the time period t1-t3). During the t3-t4 phase, a cross-validation is performed on the first converted speed (calculated by converting the actual speed of the drive wheel according to the first transmission relationship between the drive wheel and the driven wheel), the actual speed of the driven wheel, and the second converted speed (calculated by converting the average speed of the drive wheel according to the second transmission relationship between the driven wheel and the drive wheel). If the actual speed of the driven wheel matches the first converted speed, and neither the first converted speed nor the actual speed of the driven wheel matches the second converted speed, a drive wheel fault is determined. At time t4, the third converted speed, calculated by converting the actual speed of the driven wheel according to the second transmission relationship, replaces the actual speed of the driven wheel. The replaced driven wheel speed is shown in the figure. During the t4-t5 phase, the target speed ratio open-loop control is still in effect. The drive wheel fault flag is returned to record the drive wheel fault, and the related functions using the average speed of the drive wheel are disabled.

[0082] At time t5, the open-loop control of the target speed ratio is exited; during the t5-t6 period, the actual speed ratio still changes synchronously with the target speed ratio.

[0083] Through the various implementation methods provided in this embodiment, when a mismatch between the average speed of the driving wheel and the actual speed of the driven wheel is detected within a first preset time period, the actual speed of the driving wheel is converted into a first converted speed according to the first transmission relationship between the driving wheel and the driven wheel, and the average speed of the driving wheel is converted into a second converted speed according to the second transmission relationship between the driven wheel and the driving wheel. A cross-verification is performed on the first converted speed, the actual speed of the driven wheel, and the second converted speed to obtain a verification result. If the verification result indicates that the first converted speed and the second converted speed match, and both the first converted speed and the second converted speed do not match the actual speed of the driven wheel, then a fault is determined to have occurred in the driven wheel. If the verification result indicates that the first converted speed and the actual speed of the driven wheel match, and both the first converted speed and the actual speed of the driven wheel do not match the second converted speed, then a fault is determined to have occurred in the driving wheel.

[0084] As can be seen, when the average speed of the driving wheel and the actual speed of the driven wheel do not match within the first preset time period, based on the second converted speed obtained by converting the average speed of the driving wheel and the second transmission relationship between the driven wheel and the driving wheel, the first converted speed obtained by converting the actual speed of the driving wheel and the first transmission relationship between the driving wheel and the driven wheel is further used, combined with the cross-verification of the actual speed of the driven wheel, to distinguish between a fault in the driven wheel and a fault in the driving wheel, thus obtaining an accurate fault diagnosis result; so that the correct fault handling can be carried out based on the fault diagnosis result, thereby avoiding power safety risks during vehicle operation.

[0085] Next, corresponding to the above-mentioned fault determination method based on continuously variable transmission (CVT), the specific implementation of the fault determination device based on CVT in this application will be described in detail through embodiments.

[0086] See Figure 8 This illustration shows a structural schematic diagram of a fault determination device based on a continuously variable transmission (CVT) according to an embodiment of this application. In this embodiment, the device may specifically include, for example, a conversion unit 801, a verification unit 802, and a determination unit 803;

[0087] The conversion unit 801 is used to perform a conversion based on the actual speed of the driving wheel, the first transmission relationship between the driving wheel and the driven wheel, the average speed of the driving wheel and the second transmission relationship between the driven wheel and the driving wheel if a mismatch between the average speed of the driving wheel and the actual speed of the driven wheel is detected within a first preset time period, so as to obtain a first converted speed after the conversion of the actual speed of the driving wheel and a second converted speed after the conversion of the average speed of the driving wheel.

[0088] The verification unit 802 is used to perform cross-verification on the first converted speed, the actual speed of the driven wheel, and the second converted speed to obtain a verification result;

[0089] The determining unit 803 is used to determine that the driven wheel has malfunctioned if the verification result indicates that the second converted speed and the first converted speed match, and both the first converted speed and the second converted speed do not match the actual speed of the driven wheel.

[0090] The determining unit 803 is further configured to determine that the drive wheel has malfunctioned if the verification result indicates that the actual speed of the driven wheel matches the first converted speed, and neither the first converted speed nor the actual speed of the driven wheel matches the second converted speed.

[0091] In one optional embodiment of this application, the conversion unit 801 is specifically used for:

[0092] If the average speed of the drive wheel and the actual speed of the driven wheel are not matched within a second preset time period, open-loop control of the target speed ratio is requested to maintain the target speed ratio; the second preset time period is shorter than the first preset time period, and the target speed ratio is the ratio of the target speed of the drive wheel to the filtered speed of the driven wheel;

[0093] When it is detected that the average speed of the drive wheel and the actual speed of the driven wheel do not match within the first preset time period, the first converted speed and the second converted speed are obtained by conversion based on the actual speed of the drive wheel, the first transmission relationship, the average speed of the drive wheel and the second transmission relationship.

[0094] In one optional embodiment of this application, the matching of the first converted speed and the second converted speed specifically means that the difference between the first converted speed and the second converted speed conforms to a preset difference range; the mismatch between the first converted speed and the second converted speed and the actual speed of the driven wheel includes the difference between the first converted speed and the actual speed of the driven wheel not conforming to the preset difference range, and the difference between the second converted speed and the actual speed of the driven wheel not conforming to the preset difference range.

[0095] In one optional embodiment of this application, the matching of the first converted speed and the actual speed of the driven wheel specifically means that the difference between the first converted speed and the actual speed of the driven wheel conforms to a preset difference range; the mismatch between the first converted speed and the actual speed of the driven wheel and the second converted speed includes the difference between the first converted speed and the second converted speed not conforming to the preset difference range, and the difference between the actual speed of the driven wheel and the second converted speed not conforming to the preset difference range.

[0096] In one optional embodiment of this application, the device further includes: a first replacement unit;

[0097] The first substitution unit is used to substitute the actual rotational speed of the driven wheel with the second converted rotational speed.

[0098] In one optional embodiment of this application, the device further includes: a first recording and closing unit;

[0099] The first recording and shutting-down unit is used to record that the driven wheel has malfunctioned and to disable the relevant functions that use the actual rotational speed of the driven wheel.

[0100] In one optional embodiment of this application, the device further includes: a first replacement unit;

[0101] The conversion unit 801 is also used to perform a conversion based on the actual rotational speed of the driven wheel and the second transmission relationship to obtain a third converted rotational speed after the actual rotational speed of the driven wheel is converted.

[0102] The second substitution unit is used to substitute the average speed of the drive wheel with the third converted speed.

[0103] In one optional embodiment of this application, the device further includes: a second recording and closing unit;

[0104] The second-to-record and shut-down unit is used to record the failure of the drive wheel and disable the related functions that use the average speed of the drive wheel.

[0105] Through the various implementation methods provided in this embodiment, when a mismatch between the average speed of the driving wheel and the actual speed of the driven wheel is detected within a first preset time period, the actual speed of the driving wheel is converted into a first converted speed according to the first transmission relationship between the driving wheel and the driven wheel, and the average speed of the driving wheel is converted into a second converted speed according to the second transmission relationship between the driven wheel and the driving wheel. A cross-verification is performed on the first converted speed, the actual speed of the driven wheel, and the second converted speed to obtain a verification result. If the verification result indicates that the first converted speed and the second converted speed match, and both the first converted speed and the second converted speed do not match the actual speed of the driven wheel, then a fault is determined to have occurred in the driven wheel. If the verification result indicates that the first converted speed and the actual speed of the driven wheel match, and both the first converted speed and the actual speed of the driven wheel do not match the second converted speed, then a fault is determined to have occurred in the driving wheel.

[0106] As can be seen, when the average speed of the driving wheel and the actual speed of the driven wheel do not match within the first preset time period, based on the second converted speed obtained by converting the average speed of the driving wheel and the second transmission relationship between the driven wheel and the driving wheel, the first converted speed obtained by converting the actual speed of the driving wheel and the first transmission relationship between the driving wheel and the driven wheel is further used, combined with the cross-verification of the actual speed of the driven wheel, to distinguish between a fault in the driven wheel and a fault in the driving wheel, thus obtaining an accurate fault diagnosis result; so that the correct fault handling can be carried out based on the fault diagnosis result, thereby avoiding power safety risks during vehicle operation.

[0107] Furthermore, embodiments of this application also provide a computer device, which includes a processor and a memory:

[0108] The memory is used to store program code and transmit the program code to the processor;

[0109] The processor is used to execute the fault determination method based on continuously variable transmission (CVT) described in the above embodiments according to the instructions in the program code.

[0110] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0111] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0112] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0113] The above description is merely a preferred embodiment of this application and is not intended to limit the application in any way. Although this application has disclosed preferred embodiments above, it is not intended to limit the application. Any person skilled in the art can make many possible variations and modifications to the technical solutions of this application using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the technical solutions of this application. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this application without departing from the content of the technical solutions of this application shall still fall within the protection scope of the technical solutions of this application.

Claims

1. A fault determination method based on a continuously variable transmission (CVT), characterized in that, include: If the average speed of the drive wheel and the actual speed of the driven wheel are not matched within a first preset time period, the average speed of the drive wheel and the actual speed of the driven wheel are converted according to the first transmission relationship between the drive wheel and the driven wheel, the average speed of the drive wheel and the second transmission relationship between the driven wheel and the drive wheel, to obtain the first converted speed after converting the actual speed of the drive wheel and the second converted speed after converting the average speed of the drive wheel. Cross-validation is performed on the first converted speed, the actual speed of the driven wheel, and the second converted speed to obtain the validation result; If the verification result indicates that the second converted speed matches the first converted speed, and neither the first converted speed nor the second converted speed matches the actual speed of the driven wheel, then it is determined that the driven wheel has malfunctioned. If the verification result indicates that the actual speed of the driven wheel matches the first calculated speed, and neither the first calculated speed nor the actual speed of the driven wheel matches the second calculated speed, then the drive wheel is determined to be faulty.

2. The method according to claim 1, characterized in that, The step of converting the actual speed of the driving wheel, the first transmission relationship between the driving wheel and the driven wheel, the average speed of the driving wheel, and the second transmission relationship between the driven wheel and the driving wheel to obtain the first converted speed after converting the actual speed of the driving wheel and the second converted speed after converting the average speed of the driving wheel includes: If the average speed of the drive wheel and the actual speed of the driven wheel are not matched within a second preset time period, open-loop control of the target speed ratio is requested to maintain the target speed ratio; the second preset time period is shorter than the first preset time period, and the target speed ratio is the ratio of the target speed of the drive wheel to the filtered speed of the driven wheel; When it is detected that the average speed of the drive wheel and the actual speed of the driven wheel do not match within the first preset time period, the first converted speed and the second converted speed are obtained by conversion based on the actual speed of the drive wheel, the first transmission relationship, the average speed of the drive wheel and the second transmission relationship.

3. The method according to claim 1, characterized in that, The matching of the first converted speed and the second converted speed specifically means that the difference between the first converted speed and the second converted speed meets a preset difference range; the mismatch between the first converted speed and the second converted speed and the actual speed of the driven wheel includes the difference between the first converted speed and the actual speed of the driven wheel not meeting the preset difference range, and the difference between the second converted speed and the actual speed of the driven wheel not meeting the preset difference range.

4. The method according to claim 1, characterized in that, The matching of the first converted speed and the actual speed of the driven wheel specifically means that the difference between the first converted speed and the actual speed of the driven wheel meets a preset difference range; the mismatch between the first converted speed and the actual speed of the driven wheel and the second converted speed includes the difference between the first converted speed and the second converted speed not meeting the preset difference range, and the difference between the actual speed of the driven wheel and the second converted speed not meeting the preset difference range.

5. The method according to claim 1, characterized in that, After determining that the driven wheel has malfunctioned, the method further includes: The second converted speed is used to replace the actual speed of the driven wheel.

6. The method according to claim 1, characterized in that, After determining that the driven wheel has malfunctioned, the method further includes: Record the failure of the driven wheel and disable the functions related to using the actual speed of the driven wheel.

7. The method according to claim 1, characterized in that, After determining that the drive wheel has failed, the method further includes: Based on the actual rotational speed of the driven wheel and the second transmission relationship, a third converted rotational speed is obtained after converting the actual rotational speed of the driven wheel; The third converted speed is used instead of the average speed of the drive wheel.

8. The method according to claim 1, characterized in that, After determining that the drive wheel has failed, the method further includes: Record the failure of the drive wheel and disable the function related to using the average speed of the drive wheel.

9. A fault determination device based on a continuously variable transmission (CVT), characterized in that, include: Conversion unit, verification unit, and determination unit; The conversion unit is used to perform a conversion based on the actual speed of the driving wheel, the first transmission relationship between the driving wheel and the driven wheel, and the second transmission relationship between the driving wheel and the driven wheel if a mismatch between the average speed of the driving wheel and the actual speed of the driven wheel is detected within a first preset time period, so as to obtain a first converted speed after the conversion of the actual speed of the driving wheel and a second converted speed after the conversion of the average speed of the driving wheel. The verification unit is used to perform cross-verification on the first converted speed, the actual speed of the driven wheel, and the second converted speed to obtain a verification result; The determining unit is configured to determine that the driven wheel has malfunctioned if the verification result indicates that the second converted speed and the first converted speed match, and both the first converted speed and the second converted speed do not match the actual speed of the driven wheel; The determining unit is further configured to determine that the drive wheel has malfunctioned if the verification result indicates that the actual rotational speed of the driven wheel matches the first converted rotational speed, and neither the first converted rotational speed nor the actual rotational speed of the driven wheel matches the second converted rotational speed.

10. A computer device, characterized in that, The computer device includes a processor and memory: The memory is used to store program code and transmit the program code to the processor; The processor is configured to execute the fault determination method based on a continuously variable transmission as described in any one of claims 1-8 according to the instructions in the program code.

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