Vehicle transmission system protection method and device and vehicle

Abstract

The invention provides a vehicle transmission system protection method and device and a vehicle, and relates to the technical field of vehicle control systems.The vehicle transmission system protection method comprises the following steps that a predicted load of a concerned part in a transmission system load prediction model is obtained in real time, and the predicted load is calculated; when the predicted load of the concerned part meets a first preset condition, a torque reduction protection strategy is executed, and when the predicted load of the concerned part meets a second preset condition, the torque reduction protection strategy is quitted. According to the vehicle transmission system protection method, the predicted load of the concerned part is predicted through the transmission system load prediction model, and the predicted load serves as a judgment condition to determine whether to execute the torque reduction protection strategy or exit the torque reduction protection strategy; the transmission system load prediction model can be effectively utilized to predict and deal with potential load problems, so that safe and stable operation of the transmission system is protected.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control systems, and in particular to a vehicle transmission system protection method. At the same time, the present invention also relates to a vehicle transmission system protection device capable of implementing the vehicle transmission system protection method, and a vehicle equipped with the vehicle transmission system protection device. Background Art

[0002] When a vehicle passes through a bumpy road, such as a washboard road, a speed bump, or a Belgian road, the wheels may be lifted off and then land on the ground. Especially when the accelerator is high on a bumpy road, there is no friction with the road surface during the wheel lift-off phase. Under the driving torque of the power source (such as the engine and motor), the transmission system speed rises, and friction between the wheels and the ground appears at the moment of landing. The transmission system speed drops, and the potential energy accumulated in the transmission system at the moment of lift-off is released in a short time after landing, which can easily cause the transmission system components to bear a large load.

[0003] Especially when passing through continuously bumpy roads, the alternating impact loads generated will cause serious fatigue damage to the components of the transmission system. When the impact load reaches a certain intensity, it will cause the transmission system components to break and be damaged, affecting the driving safety of the vehicle.

[0004] For traditional hybrid powertrains, due to the limitation of clutch capacity, the total torque of the powertrain on bumpy roads will be limited to a certain level, which plays a certain role in impact protection. For hybrid powertrains or pure electric powertrains driven by motors without clutches, when the vehicle passes over bumpy roads, since there is no clutch, a component that limits impact loads, it is generally necessary to actively control the driving torque of the power source to effectively protect the components of the powertrain.

[0005] However, the current bumpy road protection strategy of pure electric transmission systems generally triggers the torque reduction protection strategy through abnormal fluctuations in wheel speed and motor speed. This method has the disadvantage of indirect impact load representation and is prone to false triggering of the torque reduction protection strategy. Summary of the invention

[0006] In view of this, the present invention aims to provide a vehicle transmission system protection method, so as to more accurately execute the torque reduction protection strategy, thereby better protecting the vehicle transmission system.

[0007] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0008] A vehicle transmission system protection method, the method comprising:

[0009] Obtain the predicted load of the concerned parts in the transmission system load prediction model in real time;

[0010] When the predicted load of the concerned part meets the first preset condition, executing the torque reduction protection strategy;

[0011] When the predicted load of the concerned part meets the second preset condition, the torque reduction protection strategy is exited.

[0012] As a preferred implementation, when the predicted load at the concerned part meets the first preset condition, executing the torque reduction protection strategy includes:

[0013] When the load difference between the predicted load and the nominal load of the concerned part is greater than the preset load difference, or when the predicted load of the concerned part is greater than the preset load, the torque reduction protection strategy is executed.

[0014] As a preferred implementation, when the predicted load at the concerned part meets the second preset condition, exiting the torque reduction protection strategy includes:

[0015] When the load difference between the predicted load and the nominal load of the concerned part is less than the preset load difference, the torque reduction protection strategy is exited.

[0016] As a preferred implementation, after obtaining the predicted load of the concerned part in the transmission system load prediction model in real time, the method further includes:

[0017] According to the predicted load, obtaining the predicted damage degree of the concerned part;

[0018] When the predicted damage degree meets the third preset condition, it is prompted that the concerned part has a risk of damage.

[0019] As a preferred implementation, obtaining the predicted damage degree of the concerned part according to the predicted load includes:

[0020] Obtain the operating conditions of the vehicle;

[0021] When the operating condition of the vehicle is consistent with the preset operating condition, a preset damage degree of the concerned part under the preset operating condition is obtained, and the preset damage degree is used as the predicted damage degree of the concerned part.

[0022] As a preferred implementation manner, when the predicted damage degree meets the third preset condition, prompting that the concerned part has a damage risk includes:

[0023] Calculating the current damage degree of the concerned part according to the predicted damage degree of the concerned part and the actual damage degree at the last moment;

[0024] When the current damage degree is greater than a preset damage degree threshold, it is prompted that the concerned part is at risk of damage.

[0025] As a preferred implementation, the real-time acquisition of the predicted load of the concerned part in the transmission system load prediction model includes:

[0026] Establish a transmission system load prediction model based on vehicle driving mode, gear mode, power source parameters, wheel speed, powertrain inertia and powertrain stiffness;

[0027] Embedding the transmission system load prediction model into vehicle control software;

[0028] After embedding the transmission system load prediction model into the vehicle control software, obtaining the predicted load of the concerned part in real time from the transmission system load prediction model;

[0029] The transmission system load prediction model can output the predicted load of the concerned part according to the current vehicle driving mode, current gear mode, current power source parameters and current wheel speed of the vehicle.

[0030] As a preferred implementation, the powertrain load prediction model is established based on the vehicle driving mode, gear mode, power source parameters, wheel speed, powertrain inertia and powertrain stiffness, including:

[0031] Establish an initial drivetrain load prediction model based on vehicle drive mode, gear mode, power source parameters, wheel speed, drivetrain inertia, and drivetrain stiffness;

[0032] Conduct dynamic torque load tests on the vehicle's powertrain system under various operating conditions;

[0033] During the dynamic torque load test, the theoretical dynamic load of the concerned part is obtained;

[0034] When the theoretical dynamic load of the concerned part and the predicted load of the concerned part meet a fourth preset condition, the initial transmission system load prediction model is used as the final transmission system load prediction model; otherwise, the initial transmission system load prediction model is corrected to obtain the final transmission system load prediction model;

[0035] The embedding of the transmission system load prediction model into vehicle control software comprises:

[0036] The final drive system load prediction model is embedded into the vehicle control software.

[0037] Compared with the prior art, the present invention has the following advantages:

[0038] The vehicle transmission system protection method of the present invention predicts the predicted load of the concerned part through the transmission system load prediction model, and uses this as a judgment condition to decide whether to execute the torque reduction protection strategy or exit the torque reduction protection strategy. The torque reduction protection strategy can be executed more accurately, and the impact load can be predicted by effectively using the transmission system load prediction model to conveniently and timely respond to potential load problems, thereby ensuring the safe and stable operation of the transmission system. The torque reduction protection strategy is a preventive measure that aims to reduce the load borne by the concerned part by reducing the working torque or adjusting the working parameters, thereby avoiding damage or failure due to overload.

[0039] In addition, the predicted load is the load that the concerned part may bear, which is estimated by the transmission system load prediction model. It can directly quantify the load of the concerned part, while the preset load difference and nominal load are the safety load standards. Through these two judgment conditions, possible safety problems can be effectively prevented. When the vehicle transmission system meets any of the above two first preset conditions, the system will execute the torque reduction protection strategy, which can accurately and reliably prevent the concerned part from bearing excessive impact loads.

[0040] In addition, when the load difference between the predicted load and the nominal load of the concerned part is less than the preset load difference, exiting the torque reduction protection strategy is a more stringent judgment condition, that is, the second preset condition in the present invention. When the predicted load of the concerned part meets the second preset condition, it means that the load condition of the concerned part has been restored to a relatively safe or normal range. At this time, it is no longer necessary to continue to implement the torque reduction protection strategy. After exiting the torque reduction protection strategy, the vehicle transmission system restores normal working efficiency and performance, preventing the reduction in vehicle transmission system efficiency that may be caused by working torque or parameter adjustment, and preventing unnecessary energy consumption.

[0041] Furthermore, the vehicle transmission system will evaluate the predicted degree of damage to the focus area based on the predicted load, and when the damage degree reaches or exceeds the set third preset condition, the system will issue a prompt to warn that there is a potential risk of damage to the focus area. This is an active risk management method based on prediction and preset standards, which aims to detect and prevent possible equipment failures or damage in advance, and can better prevent accidental damage to the vehicle transmission system, thereby ensuring the safety of vehicle driving.

[0042] As for obtaining the preset damage degree of the focus part under the preset operating conditions, and using the preset damage degree as the predicted damage degree of the focus part, it is equivalent to predicting the damage degree of the focus part, and the prediction process can quantify the damage degree of the focus part, thereby facilitating timely reminding the user of potential risks that may exist in the vehicle transmission system.

[0043] Calculating the current damage level of the focus area and indicating the risk of damage to the focus area based on the current damage level is conducive to accurately assessing the risk time. This method combines predictive data and historical data for judgment, and can make a more accurate assessment of the damage status of the focus area, which helps to timely discover and prevent potential failures or damage risks in the focus area of ​​the vehicle transmission system.

[0044] Another object of the present invention is to provide a control device for protecting a vehicle transmission system, comprising an acquisition unit and a control unit connected to the acquisition unit;

[0045] The acquisition unit is used to acquire the predicted load of the concerned part in the transmission system load prediction model in real time;

[0046] The control unit is used to execute the torque reduction protection strategy when the predicted load of the concerned part meets the first preset condition; and exit the torque reduction protection strategy when the predicted load of the concerned part meets the second preset condition.

[0047] At the same time, another object of the present invention is to provide a vehicle, on which is provided the control device for protecting the vehicle transmission system as described above.

[0048] The vehicle transmission system protection control device and vehicle described in the present invention have the same beneficial effects as the aforementioned vehicle transmission system protection method relative to the prior art, and will not be described in detail herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0050] Figure 1 is an exemplary flow chart of a vehicle transmission system protection method according to Embodiment 1 of the present invention;

[0051] Figure 2 This is an exemplary flow chart of predicting the degree of damage to a site of interest according to the first embodiment of the present invention;

[0052] Figure 3 is another exemplary flow chart of the vehicle transmission system protection method according to the first embodiment of the present invention;

[0053] Figure 4 This is an exemplary flow chart of how to obtain the predicted load of the concerned part according to the first embodiment of the present invention;

[0054] Figure 5 This is an exemplary flow chart of how to establish a transmission system load prediction model according to the first embodiment of the present invention;

[0055] Figure 6 is a schematic diagram of an exemplary structure of a vehicle transmission system according to Embodiment 1 of the present invention;

[0056] Figure 7 It is a schematic structural diagram of an exemplary concentrated mass system of a vehicle transmission system according to Embodiment 1 of the present invention.

[0057] Description of reference numerals:

[0058] 1. Motor; 2. Wheel; 3. First set of gear pairs; 4. Second set of gear pairs;

[0059] 301, a first driving gear; 302, a first driven gear;

[0060] 401, a second driving gear; 402, a second driven gear. DETAILED DESCRIPTION

[0061] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0062] In the description of the present invention, it should be noted that the orientation or positional relationship shown in the drawings is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0063] In addition, in the description of the present invention, unless otherwise clearly defined, the terms "installation", "connection", "connection", and "connector" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in combination with specific circumstances.

[0064] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0065] Embodiment 1

[0066] The present embodiment relates to a vehicle transmission system protection method, which aims to more accurately predict the characterization of the impact load, thereby deciding to execute or exit the torque reduction protection strategy based on the predicted impact load, thereby achieving the purpose of better protecting the vehicle transmission system.

[0067] This vehicle transmission system protection method can quantify the instantaneous loads at the vehicle transmission system's focus locations (such as the transmission input shaft, differential gears, and half shafts), identify impacts and trigger torque reduction protection strategies, and predict fatigue damage at focus locations based on predicted loads. When the damage at the focus locations reaches the fatigue limit, the customer is promptly prompted to perform repairs.

[0068] The vehicle transmission system protection method of this embodiment can better protect the vehicle transmission system, especially when the vehicle passes through bumpy roads, such as washboard roads, speed bumps, Belgian roads, cobblestone roads, etc.

[0069] Based on the above design concept, an exemplary flow chart of the vehicle transmission system protection method of this embodiment is as follows: Figure 1 As shown in , the vehicle transmission system protection method mainly includes the following steps:

[0070] S101. Obtaining predicted loads of concerned parts in a transmission system load prediction model in real time.

[0071] S102: When the predicted load of the concerned part meets the first preset condition, execute the torque reduction protection strategy.

[0072] S103: When the predicted load of the concerned part meets the second preset condition, exit the torque reduction protection strategy.

[0073] In order to better understand the vehicle transmission system protection method of this example, it should be explained here that the vehicle transmission system mentioned in this embodiment is a general term for all power transmission devices located on the power transmission path of the power source, that is, a general term for all power transmission devices that transmit the power of the power source to the vehicle wheels 2. The structure of the vehicle transmission system may be different in different vehicle models. However, the vehicle transmission system protection method of this embodiment can be used to protect any vehicle transmission system.

[0074] It should also be noted that the power source in this embodiment can be, for example, the motor 1. In addition, the power source can also be an engine, or the power source includes both the engine and the motor 1. The focus of this embodiment is the parts of the vehicle transmission system where the structural strength of the components is relatively weak, such as the input shaft, bearings, gears, differentials, etc.

[0075] It should be noted that the focus points mentioned in this embodiment include but are not limited to one focus point. That is to say, through the following transmission system load prediction model, the predicted loads of multiple focus points can be output in real time. When comparing and judging the predicted loads in the following method, the judgment is made based on the corresponding parameters of the same focus point.

[0076] It should be noted that in step S101, the transmission system load prediction model can output the predicted load of the concerned part under the premise that the transmission system load prediction model needs input parameters, and the transmission system load prediction model will output the predicted load of the concerned part based on these input parameters, which is conducive to improving the accuracy of the predicted load. The input parameters mentioned here will be described in detail below.

[0077] In addition, the predicted load of the concerned part in this embodiment is not a fixed value. It will change with the driving torque of the power source, the current driving mode of the vehicle, the current gear mode of the vehicle, the vehicle operating conditions, etc. Therefore, the predicted load is a dynamic load and needs to be obtained in real time.

[0078] like Figure 3 As shown, as a preferred implementation, as in step S102 above, when the predicted load of the concerned part meets the first preset condition, a torque reduction protection strategy is executed, specifically including S1021: when the load difference between the predicted load of the concerned part and the nominal load is greater than the preset load difference, or when the predicted load of the concerned part is greater than the preset load, a torque reduction protection strategy is executed.

[0079] It should be noted that the preset load mentioned here is the upper limit of the load that the concerned part can bear, while the nominal load refers to the load acting on the concerned part when the driving torque and speed ratio are considered.

[0080] In this step, the predicted load is the load that the concerned part may bear, which is estimated by the transmission system load prediction model. It can directly quantify the load of the concerned part, and the preset load difference and nominal load are the safety load standards. Through these two judgment conditions, possible safety problems can be effectively prevented. When the vehicle transmission system meets any of the above two first preset conditions, the system will execute the torque reduction protection strategy, which can accurately and reliably prevent the concerned part from bearing excessive impact loads.

[0081] As a preferred embodiment, continue to refer to Figure 3 As shown, when the predicted load of the concerned part meets the second preset condition, the torque reduction protection strategy is exited, specifically including S1031, when the load difference between the predicted load of the concerned part and the nominal load is less than the preset load difference, the torque reduction protection strategy is exited.

[0082] It should be noted that when the load difference between the predicted load and the nominal load of the concerned part is less than the preset load difference, exiting the torque reduction protection strategy is a more stringent judgment condition, that is, the second preset condition in the present invention. When the predicted load of the concerned part meets the second preset condition, it means that the load condition of the concerned part has been restored to a relatively safe or normal range. At this time, it is no longer necessary to continue to implement the torque reduction protection strategy. After exiting the torque reduction protection strategy, the vehicle transmission system restores normal working efficiency and performance, preventing the reduction in vehicle transmission system efficiency that may be caused by working torque or parameter adjustment, and preventing unnecessary energy consumption.

[0083] Since the implementation of the torque reduction strategy can only protect the vehicle's transmission system, the damage caused to the vehicle's transmission system by the alternating load generated when the vehicle passes over bumpy roads cannot be determined, and the existing vehicle control methods cannot quantify the impact damage.

[0084] Therefore, if Figure 2 As shown, as a preferred implementation, after obtaining the predicted load of the concerned part in the transmission system load prediction model in real time, the vehicle transmission system protection method of this embodiment further includes the following steps:

[0085] S201. Obtain the predicted damage degree of the concerned part according to the predicted load.

[0086] S202: When the predicted damage degree meets the third preset condition, it is indicated that there is a risk of damage to the concerned part.

[0087] Still refer to Figure 3 As shown, as a preferred implementation, as in step S201 above, the predicted damage degree of the concerned part is obtained according to the predicted load, which specifically includes the following steps:

[0088] S2011. Obtain the operating condition of the vehicle.

[0089] S2022. When the operating condition of the vehicle is consistent with the preset operating condition, obtain a preset damage degree of the focus part under the preset operating condition, and use the preset damage degree as the predicted damage degree of the focus part.

[0090] Here, the preset damage degree of the focus part under the preset operating condition is obtained, and the preset damage degree is used as the predicted damage degree of the focus part, which is equivalent to predicting the damage degree of the focus part, and the prediction process can quantify the damage degree of the focus part, so as to facilitate timely reminding the user of potential risks that may exist in the vehicle transmission system.

[0091] It should be noted that in step S2011, the operating conditions mentioned are mainly divided based on road conditions and vehicle speed conditions. According to the road conditions, for example, they include washboard roads, speed bumps, Belgian roads, cobblestone roads, etc., and according to the vehicle speed conditions, for example, they include accelerated driving, constant speed driving, and rapid deceleration driving.

[0092] The vehicle operating condition is any combination of the road surface condition and the vehicle driving speed condition. Taking the vehicle passing through a washboard road as an example, the vehicle operating conditions include accelerating on the washboard road, driving at a constant speed on the washboard road, and rapidly decelerating on the washboard road. When the vehicle passes through other roads, it can also be divided into three operating conditions.

[0093] It should be understood that the vehicle operating conditions mentioned above are only some exemplary vehicle operating conditions, and in addition to the vehicle operating conditions mentioned in this embodiment, other vehicle operating conditions may be set. In addition, the more preset operating conditions are divided, the more specific and accurate the quantification of the damage degree of the concerned parts will be, which is conducive to improving the accuracy and reliability of risk warnings.

[0094] Continue to refer to Figure 3 As shown, as a preferred implementation, as in the above step S202, when the predicted damage degree meets the third preset condition, prompting that the concerned part has a damage risk specifically includes the following steps:

[0095] S2021. Calculate the current damage degree of the focus area based on the predicted damage degree of the focus area and the actual damage degree at the previous moment.

[0096] S2022. When the current damage level is greater than a preset damage level threshold, it is indicated that there is a risk of damage to the concerned part.

[0097] It should be noted that the vehicle transmission system protection method of this embodiment can predict and calculate the current damage level, and when the current damage level is greater than the preset damage level threshold, it can prompt that there is a risk of damage to the focus area, which can remind the driver in time and help ensure the safety of vehicle driving.

[0098] In this step, the current damage degree of the concerned part is calculated, and the risk of damage to the concerned part is indicated based on the current damage degree, which is conducive to accurate assessment of risk time. This method combines prediction data and historical data for judgment, and can make a more accurate assessment of the damage status of the concerned part, which helps to timely discover and prevent potential failures or damage risks of the concerned part in the vehicle transmission system.

[0099] In addition, the method of prompting the presence of damage risk in the concerned part can be achieved, for example, through an existing alarm device or display screen on the vehicle. The specific method can refer to the existing alarm prompt method, and will not be described in detail in this embodiment.

[0100] In actual settings, the alarm device or display screen is connected to the control unit described below. When the control unit determines that the current damage level is greater than a preset damage level threshold, a control signal is sent to the alarm device or display screen for implementation.

[0101] The alarm device may be, for example, an existing sound alarm device, a light alarm device, etc., and the display screen may use an existing display screen on the vehicle. The prompt message may be, for example, "There is a risk of damage to XX part, please repair it in time."

[0102] like Figure 4 As shown, as a preferred implementation, as in step S101 above, the predicted load of the concerned part in the transmission system load prediction model is obtained in real time, which specifically includes the following steps:

[0103] S1011. Establish a transmission system load prediction model based on the vehicle driving mode, gear mode, power source parameters, wheel speed, power transmission system inertia and power transmission system stiffness.

[0104] S1012. Embed the transmission system load prediction model into the vehicle control software.

[0105] S1013: After embedding the transmission system load prediction model into the vehicle control software, obtain the predicted load of the concerned part in real time from the transmission system load prediction model.

[0106] It should be noted that the transmission system load prediction model in this embodiment can output the predicted load of the concerned part according to the current vehicle driving mode, current gear mode, current power source parameters and current wheel speed of the vehicle. The power source parameters may include, for example, engine driving torque, engine speed, motor driving torque, motor speed, etc.

[0107] It should also be noted that, taking a hybrid vehicle transmission system as an example, the vehicle driving mode may include at least one of a pure electric driving mode, a hybrid driving mode, a pure engine driving mode, an extended range mode, etc., which can be set according to the specific mode that the vehicle transmission system can achieve. The vehicle driving mode can be provided to the transmission system load prediction model by the vehicle controller.

[0108] The current gear mode may include, for example, 1st gear, 2nd gear, 3rd gear, etc. The number of gear modes is actually adjusted according to the type of vehicle transmission system. It should be noted that the gear mode input to the transmission system load prediction model may be provided by an existing transmission controller.

[0109] The current power source parameters, such as the engine drive torque and the engine speed, can be provided to the transmission system load prediction model by the existing engine controller, and the motor drive torque and the motor speed can be provided to the transmission system load prediction model by the existing motor controller.

[0110] In addition, the transmission system load prediction model is a lumped model that takes into account the inertia and stiffness of the transmission system. The transmission system load prediction model takes into account the influence of the transmission system inertia stiffness on the torque load of the focus parts when the speed of each component of the vehicle transmission system changes dramatically under different vehicle operating conditions. The model can also output the impact torque load of the focus parts in real time. Therefore, the application of the transmission system load prediction model for prediction is conducive to better protection of the various components of the vehicle transmission system.

[0111] In addition, in step S1011 above, information such as clutch pressure and oil temperature can also be used as a basis for establishing a transmission system load prediction model, thereby improving the prediction accuracy of the transmission system load prediction model. It should be understood that in the process of establishing the transmission system load prediction model, the relevant factors affecting the predicted load include but are not limited to the factors described above.

[0112] like Figure 5 As shown, as a preferred implementation, as in step S1011 above, a transmission system load prediction model is established according to the vehicle driving mode, gear mode, power source parameters, wheel speed, power transmission system inertia and power transmission system stiffness, specifically including the following steps:

[0113] S10111. Establish an initial transmission system load prediction model based on the vehicle driving mode, gear mode, power source parameters, wheel speed, power transmission system inertia and power transmission system stiffness.

[0114] S10112. Perform dynamic torque load tests on the vehicle's powertrain system under various operating conditions.

[0115] S10113. During the dynamic torque load test, obtain the theoretical dynamic load of the focus area.

[0116] S10114. When the theoretical dynamic load of the concerned part and the predicted load of the concerned part meet the fourth preset condition, the initial transmission system load prediction model is used as the final transmission system load prediction model; otherwise, the initial transmission system load prediction model is corrected to obtain the final transmission system load prediction model.

[0117] At this time, the aforementioned step S1012, embedding the transmission system load prediction model into the vehicle control software, specifically includes S10121, embedding the final transmission system load prediction model into the vehicle control software.

[0118] It should be noted that in step S10112 above, the multiple operating conditions refer to the vehicle operating conditions mentioned above, and the dynamic torque load test on the vehicle's powertrain system should test all vehicle operating conditions and evaluate the degree of damage to the focus parts under different alternating loads, such as fatigue life.

[0119] In addition, after performing a dynamic torque load test on the vehicle's power transmission system under various operating conditions, the vehicle transmission system method of this embodiment also includes obtaining the degree of damage of the focus area under the corresponding operating conditions based on the dynamic torque load test, and storing the obtained degree of damage in the vehicle control software.

[0120] In addition, the dynamic torque load test process is carried out using existing equipment, and load data of the concerned parts are collected during the test. The load data can be, for example, torque data T 试验 , and record the fatigue life under alternating torque.

[0121] As in step S10114 above, the initial transmission system load prediction model is corrected. Specifically, the model can be corrected by adjusting the system damping, stiffness or other unknown physical parameters to control the error of the initial transmission system load prediction model within a preset error threshold, such as 5%. The final transmission system load prediction model is obtained and embedded in the vehicle control software, so that the control unit described below can execute subsequent methods based on the predicted load of the focus area provided by the transmission system load prediction model.

[0122] It should be noted that the preset damage degree under the preset operating condition is pre-stored in the memory of the vehicle control system. For example, the stored data includes: the vehicle operating condition is accelerated driving on a washboard road, and the damage degree to the focus area A when driving for a preset time t1 is recorded as a. The vehicle accelerates on the actual washboard road for a period of time, that is, the actual driving time t2 when the vehicle is in a certain vehicle operating condition such as accelerated driving on a washboard road. For example, the method of calculating the current damage degree includes dividing t2 by t1, and then multiplying by a to obtain the current damage degree.

[0123] The vehicle transmission system protection method of this embodiment predicts the predicted load of the focus part through the transmission system load prediction model, and uses this as a judgment condition to decide whether to execute the torque reduction protection strategy or exit the torque reduction protection strategy. The torque reduction protection strategy can be executed more accurately, and the impact load can be predicted by effectively using the transmission system load prediction model to facilitate and timely respond to potential load problems, thereby ensuring the safe and stable operation of the transmission system.

[0124] Next, we will Figure 6 As an example, the vehicle transmission system shown in FIG. Figure 7The equivalent concentrated mass system shown is used to illustrate the model establishment and correction process in the above vehicle transmission system protection method.

[0125] Reference first Figure 6 As shown, the vehicle transmission system is a two-speed ratio vehicle transmission system, the power source may be, for example, a motor 1, and two sets of gear pairs are provided between the motor 1 and the wheels 2 of the vehicle.

[0126] Specifically, the vehicle transmission system includes an input shaft, an intermediate shaft and an output shaft arranged in parallel with each other, and the first gear pair 3 includes a first driving gear 301 provided on the input shaft, and a first driven gear 302 provided on the intermediate shaft, and the first driving gear 301 and the first driven gear 302 are meshed and connected. The second gear pair 4 includes a second driving gear 401 provided on the intermediate shaft, and a second driven gear 402 provided on the output shaft, and the first driving gear 301 and the first driven gear 302 are meshed and connected. The power output end of the motor 1 is connected to the input shaft, and the output shaft is connected to the wheel 2.

[0127] It should be noted here that Figure 6 The vehicle transmission system shown is only an exemplary structure, in which the power source can be an engine in addition to the motor 1, and the number of gear pairs can be other numbers. For details, please refer to the existing transmission. In addition, for example, it can also include a clutch, a synchronizer, a planetary gear system, etc.

[0128] and Figure 7 The equivalent mass system shown is based on Figure 6 For the concentrated mass system obtained by basic simplification, it should be understood that Figure 7 The equivalent mass system shown has two nodes. In this embodiment, the vehicle transmission system adopts Figure 6 When other structures are used, the number of nodes of the equivalent mass system can be changed accordingly.

[0129] Continue to refer to Figure 7 As shown in , J1 is the equivalent inertia of motor 1, J2 is the equivalent inertia of 1st speed ratio, J3 is the equivalent inertia of 2nd speed ratio, J4 is the equivalent inertia of wheel 2 and vehicle body, K1 and C1 are the equivalent stiffness and damping between J1 and J2 respectively, K2 and C2 are the equivalent stiffness and damping between J2 and J3 respectively, K3 and C3 are the equivalent stiffness and damping between J3 and J4 respectively, and M is the driving torque of motor 1.

[0130] The above parameters such as inertia, stiffness, damping, etc. can be obtained through simulation or experiment. The simulation software used is the existing software, such as Siemens AMESIM. According to the equivalent mass system model of the vehicle power transmission system established, the motion equation of the transmission system is sorted out as follows:

[0131]

[0132] Where θ1~θ4 are the torsion angles of the inertia nodes, and θ4 can represent the rotation speed of the wheel.

[0133] Convert the above equation of motion into matrix form:

[0134]

[0135] In the formula, the moment of inertia matrix [J]:

[0136]

[0137] Damping matrix [C]:

[0138]

[0139] Stiffness matrix K:

[0140]

[0141] Angular displacement column vector {θ}:

[0142] {θ}=(θ 1 θ 2 θ 3 θ 4 ) T

[0143] External excitation column vector {M}:

[0144] {M}=(M 0 0 0) T

[0145] Based on the above multi-degree-of-freedom equation, the motor drive torque M and the wheel speed are known quantities, and the transient impact load of the concerned part can be obtained, also known as the predicted load, denoted as T 预测 , and then T 预测 With T 试验 (The theoretical dynamic load in this embodiment is also called test load) comparison.

[0146] The fourth preset condition mentioned above is: based on the predicted load and the test load, the load difference between the two is obtained, and the load fluctuation is obtained by dividing the load difference by the test load. When the load fluctuation is greater than the preset load fluctuation, the transmission system load prediction model needs to be corrected.

[0147] For example, when T 预测 -T 试验 | / T 试验|>5%, correct the parameters such as stiffness and damping of the vehicle transmission system, especially the stiffness and damping of the half-shaft, such as K3 and C3 parameters (because the impact-related modes are mainly based on the half-shaft stiffness as the node, and the half-shaft front and rear vibration amplitudes are opposite in phase, the half-shaft stiffness and damping have a great influence), so that the impact load frequency, amplitude, etc. correspond to the test results, and complete the correction of the transmission system load prediction model.

[0148] It should be noted that 5% is only an exemplary preset load fluctuation amount, and the preset load fluctuation amount may be other values ​​besides 5%, such as 3%, 10%, etc. The smaller the value of the preset load fluctuation amount, the more accurate the transmission system load prediction model is.

[0149] Then, based on the vehicle data platform, the input required by the transmission system load prediction model is obtained. The transmission system load prediction model can calculate the predicted load of the concerned part, and compare the predicted load with the nominal load (driving torque multiplied by the speed ratio). When the load difference between the predicted load and the nominal load of the concerned part is greater than the preset load difference, or when the predicted load of the concerned part is greater than the preset load, the torque reduction protection strategy is executed; when the load difference between the predicted load and the nominal load of the concerned part is less than the preset load difference, the torque reduction protection strategy is exited.

[0150] Next, take the above two-stage reduction pure electric vehicle transmission system as an example to introduce the specific process:

[0151] The transmission system load prediction model obtains the data required for calculation in the vehicle data platform such as the vehicle controller. For example, in this embodiment, the data that need to be input into the transmission system load prediction model include the motor drive torque T, the motor speed, and the wheel speed.

[0152] The above data is used as the input of the transmission system load prediction model, and the transmission system load prediction model outputs the impact load of the concerned part, which is calculated as T 冲击 (predicted load at the site of interest) and compared with the nominal load T 名义 for comparison.

[0153] The nominal load is the load of the concerned part obtained by considering the driving torque and the speed ratio. For example, when the concerned part is the differential (in this embodiment, it is the position after two speed ratios, assuming the speed ratio is i), the nominal load is: T 名义 =T*i.

[0154] If the load difference between the predicted load and the nominal load of the concerned part is greater than the preset load difference, or T 冲击 When the load is greater than the preset load, such as the upper load limit, the motor torque reduction protection strategy is immediately triggered to reduce the motor torque. 冲击 and T 名义When the difference between them is less than the preset load difference within the preset cycle threshold, the torque reduction protection strategy is exited.

[0155] The preset period threshold here may be, for example, 200 ms. It should be understood that, in addition to 200 ms, the preset period threshold may also be other values, such as 150 ms, 250 ms, etc.

[0156] It should be noted that, in addition to triggering the torque reduction protection strategy based on the load difference between the predicted load and the nominal load of the concerned part being greater than the preset load difference, the strategy can also be triggered based on the following methods. For example, the difference between the predicted load and the nominal load is calculated to obtain the load difference, and the load difference is divided by the nominal load to obtain the load fluctuation amount. When the load fluctuation amount is greater than the preset load fluctuation amount, for example |T 冲击 -T 名义 | / |T 名义 |>5%, the torque reduction protection strategy is executed. The load upper limit mentioned here may be, for example, the yield limit of the concerned component.

[0157] It should be noted that 5% here is also an exemplary preset load fluctuation amount, and the preset load fluctuation amount can be other values ​​besides 5%, such as 3%, 10%, etc. The smaller the value of the preset load fluctuation amount, the more accurate the timing of executing the torque reduction protection strategy, and the more accurate and reliable the vehicle transmission system protection method is, so that various components of the vehicle transmission system can be effectively protected.

[0158] At the same time, the present embodiment relates to a vehicle transmission system protection device, which includes an acquisition unit and a control unit connected to the acquisition unit, wherein the acquisition unit is used to execute the aforementioned step S101 to acquire the predicted load of the focus part in the transmission system load prediction model in real time, and the control unit is used to execute the aforementioned steps S102 and S103, and when the predicted load of the focus part meets the first preset condition, the torque reduction protection strategy is executed; when the predicted load of the focus part meets the second preset condition, the torque reduction protection strategy is exited.

[0159] It should be noted that the specific control unit is also used to execute the aforementioned steps S1021 and S1022. In addition, the acquisition unit is also used to execute the aforementioned steps S2011 and S2012, and the control unit is also used to execute the aforementioned steps S2021 and S2022.

[0160] The specific structure of the acquisition unit may refer to the acquisition unit in the prior art. For example, the rotation speed of the wheel may be acquired through an existing rotation speed sensor, and the torque of the wheel may be acquired through an existing torque sensor.

[0161] The control unit of this embodiment may adopt an existing vehicle controller, for example. For example, the vehicle controller includes one or more processors and one or more memories. The processor may include one or more processing cores, such as a 4-core processor, an 8-core processor, and the like. The processor may be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). The processor may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state.

[0162] In some embodiments, the processor may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content that needs to be displayed on the display screen. In some embodiments, the processor may also include an AI (Artificial Intelligence) processor, which is used to process computing operations related to machine learning. The memory may include one or more computer-readable storage media, which may be non-transitory. The memory may also include high-speed random access memory, and non-volatile memory, such as one or more disk storage devices, flash memory storage devices.

[0163] In some embodiments, the non-transitory computer-readable storage medium in the memory is used to store at least one computer program, and the at least one computer program is used to be executed by the processor to implement the vehicle transmission system protection method provided in this embodiment. It can be understood by those skilled in the art that the vehicle controller may include more or fewer components, or combine certain components, or adopt different component arrangements in addition to a memory and a processor.

[0164] The vehicle transmission system protection control device of this embodiment can be used to implement the aforementioned vehicle transmission system protection method, and can better protect the various components of the vehicle transmission system. At the same time, it can also predict the degree of damage to each component, thereby promptly reminding the user of potential component damage risks, which is beneficial to ensuring the safe and stable operation of the vehicle and has good practicality.

[0165] Embodiment 2

[0166] This embodiment relates to a vehicle, on which is provided the vehicle transmission system protection device as described in the first embodiment.

[0167] The vehicle of this embodiment has the same beneficial effects as the vehicle transmission system protection method and the vehicle transmission system protection device of the first embodiment relative to the prior art, and will not be described in detail here.

[0168] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0169] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0170] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A vehicle transmission system protection method, characterized in that: The method comprises: Obtain the predicted load of the concerned parts in the transmission system load prediction model in real time; When the predicted load of the concerned part meets the first preset condition, executing the torque reduction protection strategy; When the predicted load of the concerned part meets the second preset condition, the torque reduction protection strategy is exited.

2. The vehicle transmission system protection method according to claim 1, characterized in that: When the predicted load at the concerned part meets the first preset condition, executing the torque reduction protection strategy includes: When the load difference between the predicted load and the nominal load of the concerned part is greater than the preset load difference, or when the predicted load of the concerned part is greater than the preset load, the torque reduction protection strategy is executed.

3. The vehicle transmission system protection method according to claim 1, characterized in that: When the predicted load at the concerned part meets the second preset condition, exiting the torque reduction protection strategy includes: When the load difference between the predicted load and the nominal load of the concerned part is less than the preset load difference, the torque reduction protection strategy is exited.

4. The vehicle transmission system protection method according to claim 1, characterized in that: After obtaining the predicted load of the concerned part in the transmission system load prediction model in real time, the method further includes: According to the predicted load, obtaining the predicted damage degree of the concerned part; When the predicted damage degree meets the third preset condition, it is prompted that the concerned part has a risk of damage.

5. The vehicle transmission system protection method according to claim 4, characterized in that: The step of obtaining the predicted damage degree of the concerned part according to the predicted load includes: Obtain the operating conditions of the vehicle; When the operating condition of the vehicle is consistent with the preset operating condition, a preset damage degree of the concerned part under the preset operating condition is obtained, and the preset damage degree is used as the predicted damage degree of the concerned part.

6. The vehicle transmission system protection method according to claim 4, characterized in that: When the predicted damage degree meets the third preset condition, prompting that the concerned part has a damage risk includes: Calculating the current damage degree of the concerned part according to the predicted damage degree of the concerned part and the actual damage degree at the last moment; When the current damage degree is greater than a preset damage degree threshold, it is prompted that the concerned part is at risk of damage.

7. The vehicle transmission system protection method according to any one of claims 1 to 6, characterized in that: The real-time acquisition of the predicted load of the concerned part in the transmission system load prediction model includes: Establish a transmission system load prediction model based on vehicle driving mode, gear mode, power source parameters, wheel speed, powertrain inertia and powertrain stiffness; Embedding the transmission system load prediction model into vehicle control software; After embedding the transmission system load prediction model into the vehicle control software, obtaining the predicted load of the concerned part in real time from the transmission system load prediction model; The transmission system load prediction model can output the predicted load of the concerned part according to the current vehicle driving mode, current gear mode, current power source parameters and current wheel speed of the vehicle.

8. The vehicle transmission system protection method according to claim 7, characterized in that: The method of establishing a transmission system load prediction model based on the vehicle driving mode, gear mode, power source parameters, wheel speed, power transmission system inertia and power transmission system stiffness includes: Establish an initial drivetrain load prediction model based on vehicle drive mode, gear mode, power source parameters, wheel speed, drivetrain inertia, and drivetrain stiffness; Conduct dynamic torque load tests on the vehicle's powertrain system under various operating conditions; During the dynamic torque load test, the theoretical dynamic load of the concerned part is obtained; When the theoretical dynamic load of the concerned part and the predicted load of the concerned part meet a fourth preset condition, the initial transmission system load prediction model is used as the final transmission system load prediction model; otherwise, the initial transmission system load prediction model is corrected to obtain the final transmission system load prediction model; The embedding of the transmission system load prediction model into vehicle control software comprises: The final drive system load prediction model is embedded into the vehicle control software.

9. A vehicle transmission system protection device, characterized in that: comprising an acquisition unit and a control unit connected to the acquisition unit; The acquisition unit is used to acquire the predicted load of the concerned part in the transmission system load prediction model in real time; The control unit is used to execute the torque reduction protection strategy when the predicted load of the concerned part meets the first preset condition; and exit the torque reduction protection strategy when the predicted load of the concerned part meets the second preset condition.

10. A vehicle, characterized in that: The vehicle is provided with the vehicle transmission system protection device according to claim 9.

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