Retarder fault diagnosis method and device

Abstract

This invention relates to the field of fault diagnosis technology and discloses a method and apparatus for diagnosing retarder faults. The method includes: collecting the retarder's operating state parameters; determining a torque deviation rate based on the retarder's actual braking torque and requested braking torque; obtaining the retarder's standard oil pressure under the current operating conditions; if the torque deviation rate is greater than a preset deviation rate, the retarder's requested braking torque is higher than a first preset percentage of the rated braking torque, and the oil pressure is lower than a set percentage of the standard oil pressure, then the retarder is determined to have a high-gear braking torque deficiency fault. This invention aims to at least solve the problem of difficulty in locating the cause of a retarder fault, by improving the efficiency and accuracy of retarder fault diagnosis, thus ensuring stable and reliable equipment operation.

Description

Technical Field

[0001] This invention relates to the field of fault diagnosis technology, and in particular to a method and apparatus for diagnosing retarder faults. Background Technology

[0002] Hydraulic retarders are core auxiliary braking devices for heavy vehicles. They utilize the viscous damping effect of hydraulic fluid to convert the vehicle's kinetic energy into heat energy and dissipate it outwards. The stable output of their braking torque is directly related to driving safety. However, in actual operating conditions, frequent malfunctions occur, such as broken return springs, wear between the blades and the pump body, blockage of the oil inlet, and axial movement of the pump shaft. These malfunctions can lead to problems such as failure of auxiliary braking force, sudden changes in braking torque, delayed response, or even the complete inability to establish braking torque.

[0003] Currently, the correlation between hydraulic retarder malfunctions and abnormal braking phenomena is rather vague, and there is a lack of clear criteria for determining this correlation. Troubleshooting can only be carried out by disassembling and testing each component one by one, which is not only cumbersome and time-consuming but also prone to misdiagnosis. Especially in emergency situations such as long downhill slopes, inefficient fault location can delay maintenance and further exacerbate safety risks. Summary of the Invention

[0004] The purpose of this invention is to provide a method and apparatus for diagnosing retarder faults, so as to at least solve the problem of difficulty in locating the cause of faults when retarders fail, and to improve the efficiency and accuracy of retarder fault diagnosis, thereby ensuring stable and reliable operation of the equipment.

[0005] To address the aforementioned technical problems, in a first aspect, the present invention provides a method for diagnosing retarder faults, comprising at least:

[0006] S1. Collect the operating status parameters of the retarder; the operating status parameters include at least the actual braking torque of the retarder, the requested braking torque of the retarder, the rated braking torque, and the oil pressure.

[0007] S2. Determine the torque deviation rate based on the actual braking torque of the retarder and the requested braking torque of the retarder;

[0008] S3. Obtain the standard oil pressure of the retarder under the current operating conditions of the retarder;

[0009] S4. If the torque deviation rate is greater than the preset deviation rate, the retarder requests a braking torque higher than the rated braking torque by a first preset percentage, and the oil pressure is lower than the standard oil pressure by a set percentage, then the retarder is determined to have a high-gear braking torque loss fault.

[0010] Optionally, after step S3, the method further includes:

[0011] S5. If the torque deviation rate is not greater than the preset deviation rate, the retarder requested braking torque is not higher than the first preset percentage of the rated braking torque, or the oil pressure is not lower than the set percentage of the standard oil pressure, then when the retarder is working in a fixed position, the braking torque acquisition cycle with a preset step size is set.

[0012] S6. Based on the braking torque acquisition cycle, acquire at least one cycle of the actual braking torque of the retarder;

[0013] S7. Determine the torque difference between adjacent braking torque acquisition cycles based on the actual braking torque of the retarder;

[0014] S8. Determine whether there are positive or negative fluctuations between the torque differences;

[0015] S9. If it exists, the retarder is determined to have a braking torque jump fault.

[0016] Optionally, after step S8, the method further includes:

[0017] S10. If not, obtain the working time required for the actual braking torque of the retarder to reach the preset ratio of the rated braking torque after the retarder is turned on, and monitor the oil temperature rise rate of the retarder within the working time.

[0018] S11. If the working time is greater than the preset working time and the oil temperature rise rate is less than the first preset temperature rise rate, then the retarder is determined to have a braking torque response delay fault.

[0019] Optionally, after step S10, the method further includes:

[0020] S12. If the working time is not greater than the preset working time or the oil temperature rise rate is not less than the first preset oil temperature rise rate, then continue to determine whether the actual braking torque of the retarder is less than the second preset ratio of the rated braking torque, and whether the oil temperature rise rate is less than the second preset temperature rise rate.

[0021] S13. If all values ​​are less than the specified values, the retarder is determined to be in a fault where it cannot establish braking torque in high or low gears.

[0022] Optionally, after step S12, the method further includes:

[0023] S14. If the actual braking torque of the retarder is not less than the second preset ratio of the rated braking torque or the oil temperature rise rate is not less than the second preset oil temperature rise rate, then the retarder is determined to be fault-free, and the working status parameters of the retarder are collected again.

[0024] Optionally, the method further includes:

[0025] S15. Determine the corresponding fault source, fault code, and maintenance plan prompts based on the fault category of the retarder;

[0026] S16. Upload the root cause of the fault, the fault code, and the repair plan to the vehicle display unit.

[0027] Optionally, step S15 specifically includes:

[0028] S151. If the fault category of the retarder is the high-gear braking torque loss fault, then the root cause of the fault is determined to be the broken return spring of the flow pump and the inability of the flow pump to return to the maximum eccentric position, and the corresponding fault code and the repair plan prompt are determined.

[0029] S152. If the fault category of the retarder is the braking torque jump fault, then the root cause of the fault is determined to be the abnormality of the mating end face between the pump blade and the pump body, and the corresponding fault code and the maintenance plan prompt are determined.

[0030] S153. If the fault category of the retarder is the braking torque response delay fault, then the root cause of the fault is determined to be the blockage of the flow pump inlet, and the corresponding fault code and the repair plan prompt are determined.

[0031] S154. If the fault category of the retarder is the inability to establish braking torque in high and low gears, then the root cause of the fault is determined to be abnormal pump shaft axial direction, internal leakage of oil in the flow pump, and the corresponding fault code and maintenance plan prompt are determined.

[0032] Optionally, the actual braking torque of the retarder is acquired / determined at least through the following methods:

[0033] The actual braking torque of the retarder is collected using a torque sensor; or,

[0034] S17. Obtain vehicle acceleration, gradient, vehicle weight, rolling coefficient, tire radius, equivalent coefficient of rotational inertia, transmission efficiency, and rear axle speed ratio;

[0035] S18. Determine the actual braking torque of the retarder based on the vehicle's acceleration, gradient, vehicle weight, rolling coefficient, tire radius, equivalent coefficient of rotational inertia, transmission efficiency, and rear axle speed ratio.

[0036] Optionally, the actual braking torque of the retarder is determined at least in the following ways:

[0037] ;

[0038] In the formula, Th represents the actual braking torque of the retarder, a represents the vehicle acceleration, θ represents the gradient, m represents the vehicle weight, f represents the rolling coefficient, r represents the tire radius, δ represents the equivalent coefficient of rotational inertia, η represents the transmission efficiency, and i represents the rear axle speed ratio.

[0039] Secondly, the present invention also provides a retarder fault diagnosis device, comprising at least:

[0040] The parameter acquisition module is used to acquire the operating status parameters of the retarder; the operating status parameters include at least one of the following: actual braking torque of the retarder, requested braking torque of the retarder, rated braking torque, and hydraulic pressure.

[0041] The deviation calculation module is used to determine the torque deviation rate based on the actual braking torque of the retarder and the requested braking torque of the retarder.

[0042] The oil pressure determination module is used to obtain the standard oil pressure of the retarder under the current operating conditions of the retarder.

[0043] The fault determination module is used to determine that the retarder has a high-gear braking torque loss fault when the torque deviation rate is greater than a preset deviation rate, the retarder's requested braking torque is higher than the rated braking torque by a first preset percentage, and the oil pressure is lower than the standard oil pressure by a set percentage.

[0044] The technical solution provided by this invention first collects the working status parameters of the retarder; second, it determines the torque deviation rate based on the actual braking torque and the requested braking torque of the retarder; then, it obtains the standard oil pressure of the retarder under the current operating conditions; finally, if the torque deviation rate is greater than the preset deviation rate, the requested braking torque of the retarder is higher than the rated braking torque by a first preset percentage, and the oil pressure is lower than the standard oil pressure by a set percentage, then the retarder is determined to have a high-gear braking torque loss fault.

[0045] Therefore, this invention can accurately identify and locate the cause of retarder failure by collecting the retarder's working status parameters, torque deviation rate, and standard oil pressure. This improves the efficiency of retarder fault diagnosis, reduces manual troubleshooting costs, and ensures the reliability of retarder operation. Attached Figure Description

[0046] Figure 1 This is a flowchart of a retarder fault diagnosis method provided by the present invention;

[0047] Figure 2 This is a flowchart of another retarder fault diagnosis method provided by the present invention;

[0048] Figure 3This is a schematic diagram of the structure of a retarder fault diagnosis device provided by the present invention. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0050] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0051] It should be understood that although the terms first, second, third, etc., may be used in the embodiments of the present invention, these descriptions should not be limited to these terms. These terms are only used to distinguish the descriptions. For example, first may also be referred to as second without departing from the scope of the embodiments of the present invention, and similarly, second may also be referred to as first.

[0052] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0053] It should be noted that any symbols and / or numbers present in the specification that are not marked in the accompanying drawings are not reference numerals.

[0054] Figure 1 This is a flowchart of a retarder fault diagnosis method provided by the present invention. The present invention is applicable to fault diagnosis scenarios for at least various types of vehicle retarders, and particularly applicable to fault diagnosis scenarios for variable flow pumps in integrated hydraulic retarders of vehicles. This retarder fault diagnosis method can be, but is not limited to, executed by the retarder fault diagnosis device of the present invention as the execution subject, which can be implemented in software and / or hardware. Figure 1 As shown, the retarder fault diagnosis method includes at least the following steps:

[0055] S1. Collect the working status parameters of the retarder.

[0056] The operating parameters include at least one of the following: actual braking torque of the retarder, requested braking torque of the retarder, rated braking torque, and hydraulic pressure. The retarder can be a hydraulic retarder. Rated braking torque refers to the effective braking torque that the retarder can generate under rated operating conditions, used to ensure safe, stable operation and precise positioning of the equipment.

[0057] In one specific implementation, optionally, the actual braking torque of the retarder is acquired / determined at least through the following methods:

[0058] Method 1:

[0059] The actual braking torque of the retarder is collected using a torque sensor.

[0060] Method 2:

[0061] S17. Obtain vehicle acceleration, gradient, vehicle weight, rolling coefficient, tire radius, equivalent coefficient of rotational inertia, transmission efficiency, and rear axle speed ratio.

[0062] S18. Determine the actual braking torque of the retarder based on the vehicle's acceleration, gradient, weight, rolling coefficient, tire radius, equivalent coefficient of rotational inertia, transmission efficiency, and rear axle speed ratio.

[0063] In another specific implementation, optionally, the actual braking torque of the retarder in method 2 is determined at least in the following ways:

[0064] ;

[0065] In the formula, Th represents the actual braking torque of the retarder, a represents the vehicle acceleration, θ represents the gradient, m represents the vehicle weight, f represents the rolling coefficient, r represents the tire radius, δ represents the equivalent coefficient of rotational inertia, η represents the transmission efficiency, and i represents the rear axle speed ratio.

[0066] S2. Determine the torque deviation rate based on the actual braking torque of the retarder and the requested braking torque of the retarder.

[0067] The torque deviation rate can be determined as follows:

[0068] ;

[0069] In the formula, T represents the torque deviation rate, T1 represents the actual braking torque of the retarder, and T2 represents the braking torque requested by the retarder.

[0070] S3. Obtain the standard oil pressure of the retarder under the current operating conditions.

[0071] The standard oil pressure can be obtained through calibration or pre-experimentation.

[0072] S4. If the torque deviation rate is greater than the preset deviation rate, the retarder requests a braking torque that is higher than the first preset percentage of the rated braking torque, and the oil pressure is lower than the set percentage of the standard oil pressure, then the retarder is determined to have a high-gear braking torque loss fault.

[0073] The preset deviation rate can be 80%. The first preset percentage can be 30%. The set percentage can be 60%. The high-gear braking torque loss fault may be due to the large swing resistance of the flow pump, which prevents the flow pump from returning to the maximum eccentric position, resulting in the flow rate not increasing and the oil pressure not being established when the retarder is in high gear.

[0074] The technical solution provided by this invention first collects the working status parameters of the retarder; second, it determines the torque deviation rate based on the actual braking torque and the requested braking torque of the retarder; then, it obtains the standard oil pressure of the retarder under the current operating conditions; finally, if the torque deviation rate is greater than the preset deviation rate, the requested braking torque of the retarder is higher than the rated braking torque by a first preset percentage, and the oil pressure is lower than the standard oil pressure by a set percentage, then the retarder is determined to have a high-gear braking torque loss fault.

[0075] Therefore, this invention can accurately identify and locate the cause of retarder failure by collecting the retarder's working status parameters, torque deviation rate, and standard oil pressure. This improves the efficiency of retarder fault diagnosis, reduces manual troubleshooting costs, and ensures the reliability of retarder operation.

[0076] Based on the above embodiments or implementation methods Figure 2 This is a flowchart of another retarder fault diagnosis method provided by the present invention, which is based on the above embodiments and includes additions. Figure 2 As shown, the retarder fault diagnosis method includes at least the following steps:

[0077] S1. Collect the working status parameters of the retarder.

[0078] S2. Determine the torque deviation rate based on the actual braking torque of the retarder and the requested braking torque of the retarder.

[0079] S3. Obtain the standard oil pressure of the retarder under the current operating conditions.

[0080] S5. If the torque deviation rate is not greater than the preset deviation rate, the retarder's requested braking torque is not higher than the first preset percentage of the rated braking torque, or the oil pressure is not lower than the set percentage of the standard oil pressure, then when the retarder is working in a fixed position, the braking torque acquisition cycle with a preset step size is set.

[0081] The fixed gear operation can be in gears 2-5 (braking gear). The preset step size can be 20ms.

[0082] S6. Collect the actual braking torque of the retarder for at least one cycle based on the braking torque acquisition cycle.

[0083] S7. Determine the torque difference between adjacent braking torque acquisition cycles based on the actual braking torque of the retarder.

[0084] The torque difference can be determined by subtracting the actual braking torque of the retarder from the actual braking torque collected in two adjacent braking torque acquisition cycles. For example, the torque differences obtained from n braking torque acquisition cycles are: ΔTq1, ΔTq2, ΔTq3, ..., ΔTqn.

[0085] S8. Determine whether there are positive or negative fluctuations in the torque difference.

[0086] Among them, positive and negative fluctuations can refer to the frequent fluctuations in torque difference between positive and negative values.

[0087] S10. If not, obtain the working time required for the actual braking torque of the retarder to reach the preset ratio of the rated braking torque after the retarder is turned on, and monitor the oil temperature rise rate of the retarder within the working time.

[0088] The preset proportional rated torque can be 80% of the rated torque. The time required for the actual braking torque of the retarder to reach the preset proportional rated torque after the retarder is activated can be understood as the time required from the moment the retarder is activated until its actual braking torque reaches 80% of the rated torque at the current speed. The oil temperature rise rate can be the number of degrees Celsius the oil temperature rises per second.

[0089] S12. If the working time is not greater than the preset working time or the oil temperature rise rate is not less than the first preset oil temperature rise rate, then continue to determine whether the actual braking torque of the retarder is less than the second preset ratio of the rated braking torque, and whether the oil temperature rise rate is less than the second preset temperature rise rate.

[0090] The preset working time can be a calibrated value, which can be confirmed in advance through pre-experimentation. The first preset oil temperature rise rate can be 8℃ / s. The second preset ratio can be 35%. The second preset temperature rise rate can be 5℃ / s.

[0091] In one specific implementation, optionally, after step S12, the method further includes:

[0092] S14. If the actual braking torque of the retarder is not less than the second preset ratio of the rated braking torque or the oil temperature rise rate is not less than the second preset oil temperature rise rate, then the retarder is determined to be fault-free, and the working status parameters of the retarder are re-acquired.

[0093] S13. If all values ​​are less than the specified values, the retarder is determined to be in a high / low gear failure and unable to establish braking torque.

[0094] Among them, the failure to establish braking torque in high and low gears can be a fault where braking torque cannot be established when the high and low gear hydraulic retarder is working.

[0095] S11. If the working time is longer than the preset working time and the oil temperature rise rate is less than the first preset temperature rise rate, the retarder is determined to have a braking torque response delay fault.

[0096] Among them, the braking torque response delay fault may be due to slow retarder filling and long braking torque build-up time.

[0097] S9. If present, the retarder is determined to have a braking torque jump fault.

[0098] Among them, the brake torque jump fault of the retarder may be due to abnormal matching between the pump blades and the inside of the pump body, resulting in unstable brake torque of the retarder.

[0099] S4. If the torque deviation rate is greater than the preset deviation rate, the retarder requests a braking torque that is higher than the first preset percentage of the rated braking torque, and the oil pressure is lower than the set percentage of the standard oil pressure, then the retarder is determined to have a high-gear braking torque loss fault.

[0100] In one specific implementation, the method may optionally further include:

[0101] S15. Determine the corresponding root cause of the fault, fault code, and repair solution prompts based on the fault category of the retarder.

[0102] In one specific implementation, step S15 may optionally include:

[0103] S151. If the retarder's fault category is a high-gear braking torque loss fault, then the root cause of the fault is determined to be a broken return spring of the flow pump and the flow pump's inability to return to the maximum eccentric position. The corresponding fault code and repair plan prompts are then determined.

[0104] The root causes of the malfunction in this step also include excessive oscillation resistance in the flow pump, preventing it from returning to its maximum eccentric position; and insufficient flow and inability to build up oil pressure when the retarder is in high gear. The fault code could be E101. Repair solutions can be pre-programmed into the vehicle's infotainment system by diagnostic personnel based on their past repair experience.

[0105] S152. If the retarder's fault category is braking torque jump fault, the root cause of the fault is determined to be an abnormality between the pump blade and the inner mating end face of the pump body, and the corresponding fault code and maintenance plan prompt are determined.

[0106] One possible cause is abnormal wear of the mating surfaces between the pump blades and the pump body, resulting in uneven clearance and significant flow fluctuations. The fault code could be E102.

[0107] S153. If the retarder's fault category is a braking torque response delay fault, then the root cause of the fault is determined to be a blockage at the flow pump inlet, and the corresponding fault code and repair plan prompt are determined.

[0108] The fault code could be E103.

[0109] S154. If the retarder's fault category is "failure to establish braking torque in high and low gears", then the root cause of the fault is determined to be "abnormal axial movement of the pump shaft" or "internal leakage of oil in the flow pump". Determine the corresponding fault code and repair solution.

[0110] Among them, the fault code could be E104. Internal leakage of oil in the flow pump can be caused by axial movement of the pump shaft and wear of the end face, resulting in high-pressure oil leaking into the low-pressure chamber, preventing pressure from being established, and consequently preventing the establishment of braking torque.

[0111] S16. Upload the root cause of the fault, the fault code, and the repair plan to the vehicle display unit.

[0112] The in-vehicle display unit can be the vehicle's central control display instrument panel. Specifically, the upload process involves uploading the fault source, fault code, and repair plan to the vehicle controller via the Controller Area Network (CAN) bus. The vehicle then uses this information to distribute the fault source, fault code, and repair plan to the central control display instrument panel for user access.

[0113] The technical solution provided by this invention is as follows: First, the working state parameters of the retarder are collected. Further, the torque deviation rate is determined based on the actual braking torque and the requested braking torque of the retarder. Further, the standard oil pressure of the retarder under the current operating conditions is obtained. Further, if the torque deviation rate is not greater than a preset deviation rate, the requested braking torque of the retarder is not higher than a first preset percentage of the rated braking torque, or the oil pressure is not lower than a set percentage of the standard oil pressure, then when the retarder is operating in a fixed position, a braking torque acquisition cycle with a preset step size is set. Further, the actual braking torque of the retarder for at least one cycle is collected based on the braking torque acquisition cycle. Further, the torque difference between adjacent braking torque acquisition cycles is determined based on the actual braking torque of the retarder. Further, it is determined whether there are positive or negative fluctuations between the torque differences. Further, if not, the working time required for the actual braking torque of the retarder to reach a preset proportion of the rated braking torque after the retarder is started is obtained, and the oil temperature rise rate of the retarder during the working time is monitored. Furthermore, if the operating time is not greater than the preset operating time or the oil temperature rise rate is not less than the first preset oil temperature rise rate, then it is further determined whether the actual braking torque of the retarder is less than the second preset percentage of the rated braking torque, and whether the oil temperature rise rate is less than the second preset temperature rise rate. Further, if both are less than, then the retarder is determined to have a high / low gear braking torque failure. Further, if the operating time is greater than the preset operating time, and the oil temperature rise rate is less than the first preset temperature rise rate, then the retarder is determined to have a braking torque response delay failure. Further, if both exist, then the retarder is determined to have a braking torque jump failure. Finally, if the torque deviation rate is greater than the preset deviation rate, the retarder requests a braking torque higher than the first preset percentage of the rated braking torque, and the oil pressure is lower than the set percentage of the standard oil pressure, then the retarder is determined to have a high gear braking torque deficiency failure.

[0114] Therefore, this invention, on the one hand, by collecting the retarder's operating status parameters, torque deviation rate, and standard oil pressure, can accurately identify and locate the cause of retarder failures based on these parameters, thereby improving the efficiency of retarder fault diagnosis, reducing manual troubleshooting costs, and ensuring the reliability of retarder operation. On the other hand, this invention can automatically determine the corresponding fault root cause, fault code, and repair solution prompts based on the retarder's fault category, significantly reducing the difficulty and cost of maintenance. Without disassembling the entire machine or using specialized testing equipment, maintenance personnel can quickly and accurately repair the faults based on the fault code prompts, greatly shortening maintenance time and reducing labor and parts replacement errors.

[0115] Figure 3This is a schematic diagram of a retarder fault diagnosis device provided by the present invention. The present invention is applicable to fault diagnosis scenarios for at least various types of vehicle retarders, and particularly applicable to fault diagnosis scenarios for variable flow pumps in integrated hydraulic retarders of vehicles. This retarder fault diagnosis device can be implemented using software and / or hardware. Figure 3 As shown, the retarder fault diagnosis device includes at least:

[0116] The parameter acquisition module 110 is used to acquire the working status parameters of the retarder.

[0117] The deviation calculation module 120 is used to determine the torque deviation rate based on the actual braking torque of the retarder and the requested braking torque of the retarder.

[0118] The oil pressure determination module 130 is used to obtain the standard oil pressure of the retarder under the current operating conditions of the retarder.

[0119] The fault determination module 140 is used to determine that the retarder has a high-gear braking torque loss fault when the torque deviation rate is greater than the preset deviation rate, the retarder's requested braking torque is higher than the rated braking torque by a first preset percentage, and the oil pressure is lower than the standard oil pressure by a set percentage.

[0120] Optionally, the fault determination module 140 is also used for:

[0121] When the torque deviation rate is not greater than a preset deviation rate, the retarder's requested braking torque is not higher than a first preset percentage of the rated braking torque, or the oil pressure is not lower than a set percentage of the standard oil pressure, and the retarder is operating in a fixed position, a braking torque acquisition cycle with a preset step size is set; and, based on the braking torque acquisition cycle, at least one cycle of the retarder's actual braking torque is acquired; and, based on the retarder's actual braking torque, the torque difference between adjacent braking torque acquisition cycles is determined; and, it is determined whether there are positive or negative fluctuations between the torque differences; and, if positive or negative fluctuations exist, the retarder is determined to have a braking torque jump fault.

[0122] Optionally, the fault determination module 140 is also used for:

[0123] When there are no positive or negative fluctuations, the system obtains the working time required for the actual braking torque of the retarder to reach the preset proportional rated braking torque after the retarder starts working, and monitors the oil temperature rise rate of the retarder within the working time; and when the working time is longer than the preset working time and the oil temperature rise rate is less than the first preset temperature rise rate, the system determines that the retarder has a braking torque response delay fault.

[0124] Optionally, the fault determination module 140 is also used for:

[0125] If the working time is not greater than the preset working time or the oil temperature rise rate is not less than the first preset oil temperature rise rate, continue to determine whether the actual braking torque of the retarder is less than the second preset ratio of the rated torque and whether the oil temperature rise rate is less than the second preset temperature rise rate; and if the actual braking torque of the retarder is less than the second preset ratio of the rated torque and the oil temperature rise rate is less than the second preset temperature rise rate, determine that the retarder has a high / low gear failure to establish braking torque.

[0126] Optionally, the fault determination module 140 is also used for:

[0127] If the actual braking torque of the retarder is not less than the second preset ratio of the rated braking torque or the oil temperature rise rate is not less than the second preset oil temperature rise rate, the retarder is determined to be fault-free, and the retarder's operating status parameters are re-acquired.

[0128] Optionally, it also includes:

[0129] The fault upload module 150 is used to determine the corresponding fault source, fault code and repair solution prompt according to the fault category of the retarder; and to upload the fault source, fault code and repair solution to the vehicle display unit.

[0130] Optionally, the fault upload module 150 is specifically used for:

[0131] When the retarder's fault category is a lack of braking torque in the high gear range, the root cause is determined to be a broken return spring in the flow pump, preventing the flow pump from returning to its maximum eccentric position. The corresponding fault code and repair plan are then identified. Similarly, when the retarder's fault category is a sudden change in braking torque, the root cause is determined to be an abnormality in the mating end face between the pump blades and the pump body. The corresponding fault code and repair plan are then identified. When the retarder's fault category is a delayed braking torque response, the root cause is determined to be a blockage at the flow pump's inlet. The corresponding fault code and repair plan are then identified. Finally, when the retarder's fault category is an inability to establish braking torque in both high and low gears, the root cause is determined to be an abnormal axial movement of the pump shaft, causing internal leakage of oil from the flow pump. The corresponding fault code and repair plan are then identified.

[0132] Optionally, the actual braking torque of the retarder shall be acquired / determined at least through the following methods:

[0133] The actual braking torque of the retarder is collected using a torque sensor; or,

[0134] Obtain vehicle acceleration, gradient, vehicle weight, rolling coefficient, tire radius, equivalent coefficient of rotational inertia, transmission efficiency, and rear axle ratio;

[0135] The actual braking torque of the retarder is determined based on the vehicle's acceleration, gradient, weight, rolling coefficient, tire radius, equivalent coefficient of rotational inertia, transmission efficiency, and rear axle speed ratio.

[0136] Alternatively, the actual braking torque of the retarder may be determined at least in the following ways:

[0137] ;

[0138] In the formula, Th represents the actual braking torque of the retarder, a represents the vehicle acceleration, θ represents the gradient, m represents the vehicle weight, f represents the rolling coefficient, r represents the tire radius, δ represents the equivalent coefficient of rotational inertia, η represents the transmission efficiency, and i represents the rear axle speed ratio.

[0139] The technical solution provided by this invention firstly acquires the working state parameters of the retarder through a parameter acquisition module; secondly, it determines the torque deviation rate based on the actual braking torque and the requested braking torque of the retarder through a deviation calculation module; then, it obtains the standard oil pressure of the retarder under the current operating conditions through an oil pressure determination module; finally, when the torque deviation rate is greater than a preset deviation rate, the requested braking torque of the retarder is higher than a first preset percentage of the rated braking torque, and the oil pressure is lower than a set percentage of the standard oil pressure, the fault determination module determines that the retarder has a high-gear braking torque loss fault.

[0140] Therefore, this invention can accurately identify and locate the cause of retarder failure by collecting the retarder's working status parameters, torque deviation rate, and standard oil pressure. This improves the efficiency of retarder fault diagnosis, reduces manual troubleshooting costs, and ensures the reliability of retarder operation.

[0141] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A retarder failure diagnosis method characterized by comprising: At least including: S1. Collect the working status parameters of the retarder; The operating status parameters include at least the actual braking torque of the retarder, the requested braking torque of the retarder, the rated braking torque, and the oil pressure. S2. Determine the torque deviation rate based on the actual braking torque of the retarder and the requested braking torque of the retarder; S3. Obtain the standard oil pressure of the retarder under the current operating conditions of the retarder; S4. If the torque deviation rate is greater than the preset deviation rate, the retarder requests a braking torque higher than the rated braking torque by a first preset percentage, and the oil pressure is lower than the standard oil pressure by a set percentage, then the retarder is determined to have a high-gear braking torque loss fault.

2. The method of diagnosing a failure of a retarder according to claim 1, characterized by, Following step S3, the following is also included: S5. If the torque deviation rate is not greater than the preset deviation rate, the retarder requested braking torque is not higher than the first preset percentage of the rated braking torque, or the oil pressure is not lower than the set percentage of the standard oil pressure, then when the retarder is working in a fixed position, the braking torque acquisition cycle with a preset step size is set. S6. Based on the braking torque acquisition cycle, acquire at least one cycle of the actual braking torque of the retarder; S7. Determine the torque difference between adjacent braking torque acquisition cycles based on the actual braking torque of the retarder; S8. Determine whether there are positive or negative fluctuations between the torque differences; S9. If it exists, the retarder is determined to have a braking torque jump fault.

3. The method of claim 2, wherein Following step S8, the following is also included: S10. If not, obtain the working time required for the actual braking torque of the retarder to reach the preset ratio of the rated braking torque after the retarder is turned on, and monitor the oil temperature rise rate of the retarder within the working time. S11. If the working time is greater than the preset working time and the oil temperature rise rate is less than the first preset temperature rise rate, then the retarder is determined to have a braking torque response delay fault.

4. The method of claim 3, wherein Following step S10, the method further includes: S12. If the working time is not greater than the preset working time or the oil temperature rise rate is not less than the first preset oil temperature rise rate, then continue to determine whether the actual braking torque of the retarder is less than the second preset ratio of the rated braking torque, and whether the oil temperature rise rate is less than the second preset temperature rise rate. S13. If all values ​​are less than the specified values, the retarder is determined to be in a fault where it cannot establish braking torque in high or low gears.

5. The method of diagnosing a failure of a retarder according to claim 4, characterized by, Following step S12, the following is also included: S14. If the actual braking torque of the retarder is not less than the second preset ratio of the rated braking torque or the oil temperature rise rate is not less than the second preset oil temperature rise rate, then the retarder is determined to be fault-free, and the working status parameters of the retarder are collected again.

6. The method of diagnosing a failure of the retarder according to claim 5, characterized by, The method further includes: S15. Determine the corresponding fault source, fault code, and maintenance plan prompts based on the fault category of the retarder; S16. Upload the root cause of the fault, the fault code, and the repair plan to the vehicle display unit.

7. The method of diagnosing a failure of the retarder according to claim 6, characterized by, Step S15 specifically includes: S151. If the fault category of the retarder is the high-gear braking torque loss fault, then the root cause of the fault is determined to be the broken return spring of the flow pump and the inability of the flow pump to return to the maximum eccentric position, and the corresponding fault code and the repair plan prompt are determined. S152. If the fault category of the retarder is the braking torque jump fault, then the root cause of the fault is determined to be the abnormality of the mating end face between the pump blade and the pump body, and the corresponding fault code and the maintenance plan prompt are determined. S153. If the fault category of the retarder is the braking torque response delay fault, then the root cause of the fault is determined to be the blockage of the flow pump inlet, and the corresponding fault code and the repair plan prompt are determined. S154. If the fault category of the retarder is the inability to establish braking torque in high and low gears, then the root cause of the fault is determined to be abnormal pump shaft axial direction, internal leakage of oil in the flow pump, and the corresponding fault code and maintenance plan prompt are determined.

8. The method of diagnosing a failure of a retarder according to claim 1, characterized by, The actual braking torque of the retarder is acquired / determined through at least the following methods: The actual braking torque of the retarder is collected using a torque sensor; or, S17. Obtain vehicle acceleration, gradient, vehicle weight, rolling coefficient, tire radius, equivalent coefficient of rotational inertia, transmission efficiency, and rear axle speed ratio; S18. Determine the actual braking torque of the retarder based on the vehicle's acceleration, gradient, vehicle weight, rolling coefficient, tire radius, equivalent coefficient of rotational inertia, transmission efficiency, and rear axle speed ratio.

9. The method of claim 8, wherein, The actual braking torque of the retarder is determined at least in the following ways: ； In the formula, Th represents the actual braking torque of the retarder, a represents the vehicle acceleration, θ represents the gradient, m represents the vehicle weight, f represents the rolling coefficient, r represents the tire radius, δ represents the equivalent coefficient of rotational inertia, η represents the transmission efficiency, and i represents the rear axle speed ratio.

10. A retarder failure diagnostic device characterized by, The device is used to perform the retarder fault diagnosis method as described in any one of claims 1-9; The device includes at least: The parameter acquisition module is used to acquire the operating status parameters of the retarder; the operating status parameters include at least one of the following: actual braking torque of the retarder, requested braking torque of the retarder, rated braking torque, and hydraulic pressure. The deviation calculation module is used to determine the torque deviation rate based on the actual braking torque of the retarder and the requested braking torque of the retarder. The oil pressure determination module is used to obtain the standard oil pressure of the retarder under the current operating conditions of the retarder. The fault determination module is used to determine that the retarder has a high-gear braking torque loss fault when the torque deviation rate is greater than a preset deviation rate, the retarder's requested braking torque is higher than the rated braking torque by a first preset percentage, and the oil pressure is lower than the standard oil pressure by a set percentage.

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