Vehicle axle end torque control method and device

Abstract

The invention discloses a vehicle shaft end torque control method and device, which can ensure that the acceleration of a vehicle does not cause an unexpected acceleration risk through the unexpected acceleration shaft end torque obtained by calculating the unexpected acceleration. The maximum resistance moment is calculated through the preset vehicle speed threshold value, the required shaft end torque exceeding the preset vehicle speed threshold value can be limited under the maximum resistance moment, and the maximum vehicle speed is limited. And when the required shaft end torque change value is not greater than the unexpected acceleration shaft end torque, it is indicated that the power reduction torque mapping relation is entered at the preset vehicle speed threshold value under different vehicle speed conditions, and unexpected acceleration cannot be caused. According to the method, the original torque mapping relation and the initial power reduction torque mapping relation can be obtained, then filtering can be carried out on switching between the original torque mapping relation and the initial power reduction torque mapping relation, and therefore the required shaft end torque can be output through the filtered power reduction torque mapping relation, unexpected vehicle acceleration is avoided, limitation of the maximum vehicle speed is achieved, and the vehicle running safety is improved.

Description

Technical Field

[0001] The present application relates to the field of automotive electronic technology control technology, and in particular to a method and device for controlling vehicle shaft end torque. Background Art

[0002] At present, in order to meet the driver's demand for vehicle driving quality and comfort, the vehicle's required shaft end torque is usually determined through a mapping relationship PedalMap between the accelerator pedal, the actual vehicle speed and the driver's expected torque.

[0003] In a hybrid power system, the hybrid control unit (HCU) distributes torque based on the required shaft end torque. However, when the required shaft end torque is too large, the actual output torque of the vehicle may be greater than the driver's expected demand, causing unexpected acceleration of the vehicle and affecting the personal safety of the driver and other personnel.

[0004] When the throttle opening or vehicle speed signals fail, the output of the required shaft end torque is usually too large. At present, the processing methods for this situation include interrupting the required shaft end torque data and reducing the overall percentage of the total mapping relationship. However, neither of these two methods can guarantee that the vehicle can be in a safe state when a vehicle fails, resulting in poor vehicle driving safety. Summary of the invention

[0005] In view of this, an embodiment of the present application provides a method and device for controlling the axle end torque of a vehicle, aiming to improve the safety of vehicle driving.

[0006] In a first aspect, an embodiment of the present application provides a method for controlling axle end torque of a vehicle, the method comprising:

[0007] Calculating the corresponding unexpected acceleration shaft end torque based on the unexpected acceleration; the unexpected acceleration is the unexpected increase limit of the acceleration;

[0008] Determining a coefficient of a power reduction torque mapping relationship based on a ratio between the unexpected acceleration shaft end torque and the maximum required shaft end torque; the maximum required shaft end torque is determined based on an original torque mapping relationship;

[0009] Calculating a corresponding maximum resistance torque by presetting a vehicle speed threshold, and obtaining a power reduction torque mapping relationship based on the maximum resistance torque, the coefficient and the original torque mapping relationship;

[0010] Comparing the required shaft end torque under different vehicle speed conditions with the required shaft end torque under the power reduction torque mapping relationship at the preset vehicle speed threshold, to obtain a required shaft end torque change value; the required shaft end torque under different vehicle speed conditions is obtained by mapping different vehicle speeds through the original torque mapping relationship;

[0011] When the required shaft end torque change value is not greater than the unexpected acceleration shaft end torque, the switching between the derated power torque mapping relationship and the original torque mapping relationship is filtered to obtain a filtered derated power torque mapping relationship.

[0012] Optionally, the method further comprises:

[0013] When the required shaft end torque change value is greater than the unexpected acceleration shaft end torque, the power reduction torque mapping relationship is subjected to slope change processing, and the switching between the processed power reduction torque mapping relationship and the original torque mapping relationship is filtered to obtain a filtered power reduction torque mapping relationship.

[0014] Optionally, the calculating of the unexpected acceleration shaft end torque corresponding to the unexpected acceleration based on the unexpected acceleration also includes:

[0015] Detect the input signal of the required shaft end torque to obtain the detection result;

[0016] When the detection result is an input signal failure, the required shaft end torque is output based on the power reduction torque mapping relationship.

[0017] Optionally, the method further comprises:

[0018] When the detection result shows that the input signal is normal, the required shaft end torque is output based on the original torque mapping relationship.

[0019] Optionally, the input signal includes a sensor signal and a communication signal, and the detecting the input signal of the required shaft end torque to obtain the detection result includes:

[0020] Perform fault diagnosis on the sensor signal of the required shaft end torque to obtain the fault diagnosis result;

[0021] Performing data verification on the communication signal of the required shaft end torque to obtain a data verification result;

[0022] A detection result is obtained based on the fault diagnosis result and the data verification result.

[0023] In a second aspect, an embodiment of the present application provides a device for controlling axle end torque of a vehicle, the device comprising:

[0024] A first calculation module is used to calculate the corresponding unexpected acceleration shaft end torque based on the unexpected acceleration; the unexpected acceleration is an unexpected increase limit of the acceleration;

[0025] A determination module, configured to determine a coefficient of a power reduction torque mapping relationship based on a ratio between the unexpected acceleration shaft end torque and a maximum required shaft end torque; the maximum required shaft end torque is determined based on an original torque mapping relationship;

[0026] A second calculation module is used to calculate the corresponding maximum resistance torque according to the preset vehicle speed threshold, and obtain a power reduction torque mapping relationship based on the maximum resistance torque, the coefficient and the original torque mapping relationship;

[0027] a comparison module, configured to compare the required shaft end torque under different vehicle speed conditions with the required shaft end torque under the power reduction torque mapping relationship at the preset vehicle speed threshold, to obtain a required shaft end torque change value; the required shaft end torque under different vehicle speed conditions is obtained by mapping different vehicle speeds through the original torque mapping relationship;

[0028] The filtering module is used to filter the switching between the power reduction torque mapping relationship and the original torque mapping relationship when the required shaft end torque change value is not greater than the unexpected acceleration shaft end torque to obtain a filtered power reduction torque mapping relationship.

[0029] Optionally, the device further comprises:

[0030] A processing unit is used to perform slope change processing on the power reduction torque mapping relationship when the required shaft end torque change value is greater than the unexpected acceleration shaft end torque, and filter the switching between the processed power reduction torque mapping relationship and the original torque mapping relationship to obtain a filtered power reduction torque mapping relationship.

[0031] Optionally, the first calculation module further includes:

[0032] A detection unit, used to detect an input signal of a required shaft end torque and obtain a detection result;

[0033] The first output unit is used to output the required shaft end torque based on the power reduction torque mapping relationship when the detection result is an input signal failure.

[0034] Optionally, the device further comprises:

[0035] The second output unit is used to output the required shaft end torque based on the original torque mapping relationship when the detection result shows that the input signal is normal.

[0036] Optionally, the detection unit comprises:

[0037] A diagnostic unit, used for performing fault diagnosis on a sensor signal of a required shaft end torque to obtain a fault diagnosis result;

[0038] A verification unit, used for performing data verification on the communication signal of the required shaft end torque to obtain a data verification result;

[0039] An obtaining unit is used to obtain a detection result based on the fault diagnosis result and the data verification result.

[0040] In a third aspect, an embodiment of the present application provides a vehicle shaft end torque control device, the device comprising:

[0041] Memory for storing computer programs;

[0042] The processor is used to execute the computer program so that the device executes the vehicle axle end torque control method described in the first aspect.

[0043] In a fourth aspect, an embodiment of the present application provides a computer storage medium, wherein a computer program is stored on the computer-readable storage medium. When the computer program is executed, the device executing the computer program implements the vehicle axle end torque control method described in the first aspect above.

[0044] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0045] The embodiment of the present application provides a method and device for controlling the shaft end torque of a vehicle. The unexpected acceleration shaft end torque corresponding to the unexpected acceleration is calculated based on the unexpected acceleration, and the unexpected acceleration is the unexpected increase limit of the acceleration. Based on the ratio between the unexpected acceleration shaft end torque and the maximum required shaft end torque, the coefficient of the power reduction torque mapping relationship is determined, and the maximum required shaft end torque is determined based on the original torque mapping relationship. The corresponding maximum resistance torque is calculated by a preset vehicle speed threshold, and the power reduction torque mapping relationship is obtained based on the maximum resistance torque, the coefficient and the original torque mapping relationship. The required shaft end torque under different vehicle speeds is compared with the required shaft end torque under the power reduction torque mapping relationship with the preset vehicle speed threshold, and the required shaft end torque change value is obtained. The required shaft end torque under different vehicle speeds is obtained by mapping different vehicle speeds through the original power torque mapping relationship. When the required shaft end torque change value is not greater than the unexpected acceleration shaft end torque, the switching between the power reduction torque mapping relationship and the original torque mapping relationship is filtered to obtain the filtered power reduction torque mapping relationship.

[0046] It can be seen that the unexpected acceleration shaft end torque calculated by the unexpected acceleration can ensure that the acceleration of the vehicle will not cause unexpected acceleration risks. By calculating the maximum resistance torque by presetting the vehicle speed threshold, the required shaft end torque exceeding the preset vehicle speed threshold can be limited to the maximum resistance torque, thereby realizing the limitation of the maximum vehicle speed. Thus, based on the coefficient, the maximum resistance torque and the original torque mapping relationship, a preliminary power reduction torque mapping relationship can be obtained. When the required shaft end torque change value is not greater than the unexpected acceleration shaft end torque, it means that entering the power reduction torque mapping relationship with the preset vehicle speed threshold under different vehicle speed conditions will not cause unexpected acceleration. Then, the switching between the original torque mapping relationship and the preliminary power reduction torque mapping relationship can be filtered, so that the required shaft end torque can be output through the filtered power reduction torque mapping relationship, thereby avoiding unexpected vehicle acceleration and realizing the limitation of the maximum vehicle speed, thereby improving the safety of vehicle driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in this embodiment or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 A schematic diagram of a required shaft end torque calculation structure provided by the prior art;

[0049] Figure 2 A flow chart of a method for controlling axle end torque of a vehicle provided in an embodiment of the present application;

[0050] Figure 3 A schematic diagram of input signal detection provided in an embodiment of the present application;

[0051] Figure 4 A schematic diagram for comparing the original required shaft end torque and the reduced power required shaft end torque provided in an embodiment of the present application;

[0052] Figure 5 A schematic diagram of the structure of a vehicle axle end torque control device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0054] See also Figure 1 , Figure 1 This is a schematic diagram of the calculation structure of the required shaft end torque in the prior art. The required shaft end torque can be obtained through the accelerator pedal position, vehicle speed signal, gear signal and brake pedal switch signal through the torque mapping relationship PedalMap. At the same time, the mapping relationship is different under different working conditions and modes. In the hybrid system, the torque is distributed and implemented based on the HCU and the required shaft end torque. When the required shaft end torque is too large, it will cause unexpected acceleration of the vehicle, which may endanger the personal safety of personnel in certain scenarios. The deceleration control of hybrid vehicles can be achieved through the assistance of brake energy recovery. Since the braking deceleration required torque is not provided by PedalMap, the unexpected deceleration scenario is not considered in this application.

[0055] When an unexpected demand shaft end torque risk occurs, controlling the driver's demand shaft end torque to enter a safe state is the key to ensuring the safety of the vehicle and personnel.

[0056] However, in actual applications, when there are problems with signals such as throttle opening and vehicle speed, methods for controlling the required shaft-end torque include interrupting the required shaft-end torque output or reducing the total mapping relationship by an overall percentage. If interrupting the required shaft-end torque output will cause unexpected torque loss in the vehicle, the vehicle will not be able to respond to the driver's torque request in certain scenarios, which may lead to safety accidents. The total mapping relationship is reduced by an overall percentage, and the reduction percentage is usually an empirical value and cannot guarantee that it can be in a safe state under every operating condition. Therefore, neither of these two methods can guarantee that the vehicle can be in a safe state when the vehicle fails under various operating conditions, resulting in poor vehicle driving safety.

[0057] Based on this, in order to solve the above problems, the embodiment of the present application provides a method for controlling the shaft end torque of a vehicle. The unexpected acceleration shaft end torque obtained by calculating the unexpected acceleration can ensure that the acceleration of the vehicle will not cause unexpected acceleration risks. By calculating the maximum resistance torque by presetting the vehicle speed threshold, the required shaft end torque exceeding the preset vehicle speed threshold can be limited to the maximum resistance torque, thereby realizing the limitation of the maximum vehicle speed. Thus, based on the coefficient, the maximum resistance torque and the original torque mapping relationship, a preliminary power reduction torque mapping relationship can be obtained. When the required shaft end torque change value is not greater than the unexpected acceleration shaft end torque, it means that under different vehicle speed conditions, entering the power reduction torque mapping relationship with the preset vehicle speed threshold will not cause unexpected acceleration. Then, the switching between the original torque mapping relationship and the preliminary power reduction torque mapping relationship can be filtered, so that the required shaft end torque can be output through the filtered power reduction torque mapping relationship, thereby avoiding unexpected vehicle acceleration and realizing the limitation of the maximum vehicle speed, thereby improving the safety of vehicle driving.

[0058] The specific implementation of the method and device for controlling the vehicle shaft end torque in the embodiment of the present application will be described in detail below with reference to the accompanying drawings by way of examples.

[0059] See also Figure 2 , which is a flow chart of a method for controlling axle end torque of a vehicle provided in an embodiment of the present application, combined with Figure 2 As shown, it may specifically include:

[0060] S201: Calculate the corresponding unexpected acceleration shaft end torque based on the unexpected acceleration, where the unexpected acceleration is the unexpected increase limit of the acceleration.

[0061] This application is mainly used in cases where functions such as non-cruise control, non-adaptive cruise control, and non-active speed limit are activated. At this time, the driver's required shaft end torque can be obtained by mapping the accelerator pedal and vehicle speed signal.

[0062] In one possible implementation, see Figure 3 , Figure 3A schematic diagram of input signal detection provided in an embodiment of the present application, firstly, the input signal of the vehicle is diagnosed, wherein the input signal that affects the required shaft end torque of the vehicle is mainly divided into two types, namely, sensor signal and communication signal (English: Controller Area Network, CAN), the sensor signal includes the accelerator pedal opening signal and the brake pedal switch signal, the CAN signal includes the vehicle speed signal and the gear position signal, and the corresponding electrical fault and rationality fault diagnosis can be performed on the sensor signal to obtain the fault diagnosis result. The corresponding data verification (English: end to end, E2E) and frame timeout detection can be performed on the CAN signal to obtain the data verification result. Therefore, the fault diagnosis result and the data verification result are combined to obtain the detection result, which is used to determine whether there is a fault in the input signal.

[0063] When the detection result is an input signal failure, such as a sensor signal short circuit or a CAN signal loss, the required shaft-end torque is output through the power-reduction torque mapping relationship, that is, the required shaft-end torque is output through the power-reduction PedalMap, thereby ensuring the safe state of outputting the required shaft-end torque and not causing the risk of unexpected acceleration of the vehicle.

[0064] When the detection result shows that the input signal is normal, the required shaft end torque is output through the original torque mapping relationship, that is, the required shaft end torque is output through the normal PedalMap.

[0065] When the input signal fails, the required shaft end torque can be output by reducing the power PedalMap. Therefore, the calculation process of reducing the power PedalMap is specifically introduced below.

[0066] In order to ensure that the acceleration of the vehicle does not cause unexpected acceleration risks when a failure occurs, it is necessary to limit the unexpected acceleration of the vehicle to ensure the personal safety of the vehicle and the driver. As an example, the unexpected acceleration can be set to 0.2g, which is 0.2 times the acceleration of gravity. Unexpected acceleration refers to the unexpected increase limit of the vehicle acceleration in the event of a vehicle failure. Then, based on the unexpected acceleration, the corresponding unexpected acceleration shaft-end torque can be calculated. The unexpected acceleration shaft-end torque can be expressed by Axl_0.2g=M*0.2*g*R, where M is the vehicle mass, R is the tire radius, and g is the acceleration of gravity.

[0067] S202: Determine a coefficient of a power reduction torque mapping relationship based on a ratio between an unexpected acceleration shaft end torque and a maximum required shaft end torque, wherein the maximum required shaft end torque is determined based on an original torque mapping relationship.

[0068] In a possible implementation, the maximum required shaft end torque Pdlmap_Axl_Max can be determined from the original torque mapping relationship PedalMap, and the maximum required shaft end torque is the required shaft end torque that can cause the maximum acceleration of the vehicle. The coefficient of the power reduction PedalMap can be determined based on the ratio between the unexpected acceleration shaft end torque Axl_0.2g and the maximum required shaft end torque, and the coefficient factor=Axl_0.2g / Pdlmap_Axl_Max. Therefore, the preliminary power reduction torque mapping relationship can be determined based on the coefficient multiplied by the original torque mapping relationship, and the preliminary power reduction torque mapping relationship PedalMap_Raw=original PedalMap*factor. Therefore, the preliminary power reduction torque mapping relationship limited by unexpected acceleration can ensure that when a vehicle fails, even if the calculated required shaft end torque reaches the maximum value, the actual output required shaft end torque will not cause the vehicle to have an unexpected acceleration problem of exceeding 0.2g.

[0069] S203: Calculate the corresponding maximum resistance torque by presetting the vehicle speed threshold, and obtain a power reduction torque mapping relationship based on the maximum resistance torque, the coefficient and the original torque mapping relationship.

[0070] The purpose of the present application is to design a PedalMap that can adapt to various working conditions, so as to ensure that when the input signal fails or is unreliable, there is no risk of unexpected acceleration of the vehicle. Therefore, in the design process of the PedalMap, in addition to considering the changes in the shaft end torque that may cause unexpected acceleration, the changes in the actual driving resistance are also considered.

[0071] In order to avoid danger due to excessive speed in the event of a vehicle failure or failure of related input signals, the speed of the entire vehicle needs to be limited. As an example, the preset speed threshold of the entire vehicle in the event of a failure may be below 80 kph, and the vehicle's driving resistance may be calculated based on the preset speed threshold, that is, the vehicle's driving resistance when the speed is 80 kph.

[0072] In a possible implementation, the maximum drag torque can be obtained through the vehicle target drag curve, f=av 2 +bv+c, f is the maximum resistance torque, v is the vehicle speed, a, b, c are the resistance parameters verified by vehicle test calibration. Based on the preliminary power reduction PedalMap, the vehicle speed can be limited to limit the required shaft end torque above 80kph to below the maximum resistance torque F, thereby achieving the maximum vehicle speed limitation, and thus the power reduction torque mapping relationship PedalMap_Raw2 can be obtained.

[0073] S204: Compare the required shaft end torque under different vehicle speed conditions and the required shaft end torque under the power reduction torque mapping relationship with a preset vehicle speed threshold to obtain a change value of the required shaft end torque. The required shaft end torque under different vehicle speed conditions is obtained by mapping different vehicle speeds through the original torque mapping relationship.

[0074] In one possible implementation, when the vehicle speed signal is unreliable, a default vehicle speed of 80 kph is selected to enter the power reduction torque mapping relationship PedalMap_Raw2, and there is a certain difference between the actual vehicle speed and the default vehicle speed. For example, when the vehicle speed signal is unreliable, the vehicle speed entering the power reduction torque mapping relationship PedalMap_Raw2 is 80 kph, but the actual vehicle speed is 50 kph.

[0075] In this case, it is necessary to evaluate the required shaft end torque under various vehicle speed conditions obtained by mapping different vehicle speeds through the original torque mapping relationship under various working conditions, and compare it with the required shaft end torque output when entering the power reduction torque mapping relationship PedalMap_Raw2 at 80kph, so as to obtain the required shaft end torque change value. Then, it can be compared whether the required shaft end torque change value exceeds the unexpected acceleration shaft end torque, which is used to determine whether the required shaft end torque output when entering the power reduction torque mapping relationship PedalMap_Raw2 at 80kph under different vehicle speed conditions will have the risk of unexpected acceleration.

[0076] S205: When the required shaft end torque change value is not greater than the unexpected acceleration shaft end torque, filtering the switching between the reduced power torque mapping relationship and the original torque mapping relationship to obtain a filtered reduced power torque mapping relationship.

[0077] When the change value of the required shaft end torque under different vehicle speed conditions is less than or equal to the unexpected acceleration shaft end torque, it means that when entering the power reduction torque mapping relationship PedalMap_Raw2 at 80kph under different vehicle speed conditions, the output required shaft end torque has no risk of unexpected acceleration. PedalMap_Raw2 can be directly used as the power reduction PedalMap. In addition, the switching between PedalMap_Raw2 and the original PedalMap needs to be switched and filtered to avoid vehicle impact and affect vehicle driving safety. Finally, the filtered power reduction torque mapping relationship can be used as the final power reduction PedalMap with speed limit.

[0078] When the change value of the required shaft end torque under different vehicle speed conditions is greater than the unexpected acceleration shaft end torque, it means that when entering the power reduction torque mapping relationship PedalMap_Raw2 at 80kph under different vehicle speed conditions, the output required shaft end torque has the risk of unexpected acceleration. At this time, the power reduction torque mapping relationship can be processed with a slope change Ramp, that is, the process of processing according to a certain slope change, thereby obtaining the processed power reduction torque mapping relationship. Then, the switching between the original torque mapping relationship and the processed power reduction torque mapping relationship can be switched and filtered, so that the filtered power reduction torque mapping relationship can be used as the final power reduction PedalMap with vehicle speed limit.

[0079] See also Figure 4 , Figure 4 A schematic diagram of the comparison between the original required shaft end torque and the reduced power required shaft end torque provided in the embodiment of the present application is used to compare the original required shaft end torque and the reduced power shaft end required torque at the throttle opening of 40% and 80%. In the working condition where the vehicle speed is less than 80kph, the target required shaft end torque is degraded by the coefficient factor. In the working condition where the vehicle speed is greater than 80kph, the target required shaft end torque is limited to the vehicle driving resistance at 80kph, so as to ensure that the actual vehicle speed does not exceed the maximum value.

[0080] Therefore, after adopting the power reduction safety control method provided in the implementation of this application, for the output of the shaft end torque required by the hybrid vehicle, when the vehicle speed signal, accelerator pedal signal, gear signal, and brake switch signal fail, the power reduction PedalMap can be entered to avoid unexpected vehicle acceleration, thereby effectively improving the vehicle driving safety.

[0081] The above is a method for controlling the shaft end torque of a vehicle provided in an embodiment of the present application. The corresponding unexpected acceleration shaft end torque is calculated based on the unexpected acceleration, and the unexpected acceleration is the unexpected increase limit of the acceleration. Based on the ratio between the unexpected acceleration shaft end torque and the maximum demand shaft end torque, the coefficient of the power reduction torque mapping relationship is determined, and the maximum demand shaft end torque is determined based on the original torque mapping relationship. The corresponding maximum resistance torque is calculated by the preset vehicle speed threshold, and the power reduction torque mapping relationship is obtained based on the maximum resistance torque, the coefficient and the original torque mapping relationship. The demand shaft end torque under different vehicle speed conditions is compared with the demand shaft end torque under the power reduction torque mapping relationship with the preset vehicle speed threshold, and the demand shaft end torque change value is obtained. The demand shaft end torque under different vehicle speed conditions is obtained by mapping different vehicle speeds through the original power torque mapping relationship. When the demand shaft end torque change value is not greater than the unexpected acceleration shaft end torque, the switching between the power reduction torque mapping relationship and the original torque mapping relationship is filtered to obtain the filtered power reduction torque mapping relationship.

[0082] It can be seen that the unexpected acceleration shaft end torque calculated by the unexpected acceleration can ensure that the acceleration of the vehicle will not cause unexpected acceleration risks. By calculating the maximum resistance torque by presetting the vehicle speed threshold, the required shaft end torque exceeding the preset vehicle speed threshold can be limited to the maximum resistance torque, thereby realizing the limitation of the maximum vehicle speed. Thus, based on the coefficient, the maximum resistance torque and the original torque mapping relationship, a preliminary power reduction torque mapping relationship can be obtained. When the required shaft end torque change value is not greater than the unexpected acceleration shaft end torque, it means that entering the power reduction torque mapping relationship with the preset vehicle speed threshold under different vehicle speed conditions will not cause unexpected acceleration. Then, the switching between the original torque mapping relationship and the preliminary power reduction torque mapping relationship can be filtered, so that the required shaft end torque can be output through the filtered power reduction torque mapping relationship, thereby avoiding unexpected vehicle acceleration and realizing the limitation of the maximum vehicle speed, thereby improving the safety of vehicle driving.

[0083] The above are some specific implementations of the vehicle shaft end torque control method provided by the embodiment of the present application. Based on this, the present application also provides a corresponding device. The device provided by the embodiment of the present application will be introduced from the perspective of functional modularization.

[0084] See also Figure 5 , which is a schematic diagram of the structure of a vehicle shaft end torque control device 500 provided in an embodiment of the present application, and the device 500 may include:

[0085] A first calculation module 501 is used to calculate the corresponding unexpected acceleration shaft end torque based on the unexpected acceleration; the unexpected acceleration is the unexpected increase limit of the acceleration;

[0086] A determination module 502 is used to determine a coefficient of a power reduction torque mapping relationship based on a ratio between the unexpected acceleration shaft end torque and the maximum required shaft end torque; the maximum required shaft end torque is determined based on an original torque mapping relationship;

[0087] A second calculation module 503 is used to calculate the corresponding maximum resistance torque according to the preset vehicle speed threshold, and obtain a power reduction torque mapping relationship based on the maximum resistance torque, the coefficient and the original torque mapping relationship;

[0088] A comparison module 504 is used to compare the required shaft end torque under different vehicle speed conditions with the required shaft end torque under the power reduction torque mapping relationship at the preset vehicle speed threshold, to obtain a required shaft end torque change value; the required shaft end torque under different vehicle speed conditions is obtained by mapping different vehicle speeds through the original torque mapping relationship;

[0089] The filtering module 505 is used to filter the switching between the derated power torque mapping relationship and the original torque mapping relationship to obtain a filtered derated power torque mapping relationship when the required shaft end torque change value is not greater than the unexpected acceleration shaft end torque.

[0090] In the embodiment of the present application, through the cooperation between the first calculation module 501, the determination module 502, the second calculation module 503, the comparison module 504 and the filtering module 505, the unexpected acceleration shaft end torque obtained by the unexpected acceleration calculation can ensure that the acceleration of the vehicle will not cause unexpected acceleration risks. By calculating the maximum resistance torque by the preset vehicle speed threshold, the required shaft end torque exceeding the preset vehicle speed threshold can be limited to the maximum resistance torque, thereby realizing the limitation of the maximum vehicle speed. Thus, based on the coefficient, the maximum resistance torque and the original torque mapping relationship, a preliminary power reduction torque mapping relationship can be obtained. When the required shaft end torque change value is not greater than the unexpected acceleration shaft end torque, it means that under different vehicle speed conditions, entering the power reduction torque mapping relationship with the preset vehicle speed threshold will not cause unexpected acceleration. Then, the switching between the original torque mapping relationship and the preliminary power reduction torque mapping relationship can be filtered, so that the required shaft end torque can be output through the filtered power reduction torque mapping relationship, thereby avoiding unexpected vehicle acceleration and realizing the limitation of the maximum vehicle speed, thereby improving the safety of vehicle driving.

[0091] As an implementation manner, the vehicle shaft end torque control device 500 further includes:

[0092] A processing unit is used to perform slope change processing on the power reduction torque mapping relationship when the required shaft end torque change value is greater than the unexpected acceleration shaft end torque, and filter the switching between the processed power reduction torque mapping relationship and the original torque mapping relationship to obtain a filtered power reduction torque mapping relationship.

[0093] As an implementation manner, the first calculation module 501 also includes:

[0094] A detection unit, used to detect an input signal of a required shaft end torque and obtain a detection result;

[0095] The first output unit is used to output the required shaft end torque based on the power reduction torque mapping relationship when the detection result is an input signal failure.

[0096] As an implementation manner, the vehicle shaft end torque control device 500 further includes:

[0097] The second output unit is used to output the required shaft end torque based on the original torque mapping relationship when the detection result shows that the input signal is normal.

[0098] As an implementation mode, the detection unit includes:

[0099] A diagnostic unit, used for performing fault diagnosis on a sensor signal of a required shaft end torque to obtain a fault diagnosis result;

[0100] A verification unit, used for performing data verification on the communication signal of the required shaft end torque to obtain a data verification result;

[0101] An obtaining unit is used to obtain a detection result based on the fault diagnosis result and the data verification result.

[0102] The embodiments of the present application also provide corresponding devices and computer storage media for implementing the solutions provided by the embodiments of the present application.

[0103] The device includes a memory and a processor, the memory is used to store a computer program, and the processor is used to execute the computer program, so that the device executes the vehicle axle end torque control method described in any embodiment of the present application.

[0104] The computer storage medium stores a computer program. When the code is executed, the device executing the computer program implements the method for controlling the vehicle axle end torque described in any embodiment of the present application.

[0105] The "first" and "second" in the names such as "first" and "second" (if any) mentioned in the embodiments of the present application are only used as name identifiers and do not represent the first or second in order.

[0106] Through the description of the above implementation methods, it can be known that those skilled in the art can clearly understand that all or part of the steps in the above-mentioned embodiment method can be implemented by means of software plus a general hardware platform. Based on such an understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a storage medium, such as a read-only memory (ROM) / RAM, a magnetic disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network communication device such as a router) to execute the methods described in each embodiment of the present application or some parts of the embodiments.

[0107] It should be noted that each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The device embodiment described above is merely schematic, in which the unit described as a separate component may or may not be physically separated, and the component prompted as a unit may or may not be a physical unit, that is, it may be located in one place, or it may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative work.

[0108] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for controlling the torque at the shaft end of a vehicle, It is characterized in that The method comprises: Calculating the corresponding unexpected acceleration shaft end torque based on the unexpected acceleration; the unexpected acceleration is the unexpected increase limit of the acceleration; Determining a coefficient of a power reduction torque mapping relationship based on a ratio between the unexpected acceleration shaft end torque and the maximum required shaft end torque; the maximum required shaft end torque is determined based on an original torque mapping relationship; Calculating a corresponding maximum resistance torque by presetting a vehicle speed threshold, and obtaining a power reduction torque mapping relationship based on the maximum resistance torque, the coefficient and the original torque mapping relationship; Comparing the required shaft end torque under different vehicle speed conditions with the required shaft end torque under the power reduction torque mapping relationship at the preset vehicle speed threshold, to obtain a required shaft end torque change value; the required shaft end torque under different vehicle speed conditions is obtained by mapping different vehicle speeds through the original torque mapping relationship; When the required shaft end torque change value is not greater than the unexpected acceleration shaft end torque, the switching between the derated power torque mapping relationship and the original torque mapping relationship is filtered to obtain a filtered derated power torque mapping relationship.

2. The method according to claim 1, It is characterized in that The method further comprises: When the required shaft end torque change value is greater than the unexpected acceleration shaft end torque, the power reduction torque mapping relationship is subjected to slope change processing, and the switching between the processed power reduction torque mapping relationship and the original torque mapping relationship is filtered to obtain a filtered power reduction torque mapping relationship.

3. The method according to claim 1, It is characterized in that The unexpected acceleration shaft end torque corresponding to the unexpected acceleration calculation is also previously included: Detect the input signal of the required shaft end torque to obtain the detection result; When the detection result is an input signal failure, the required shaft end torque is output based on the power reduction torque mapping relationship.

4. The method according to claim 3, It is characterized in that The method further comprises: When the detection result shows that the input signal is normal, the required shaft end torque is output based on the original torque mapping relationship.

5. The method according to claim 3, It is characterized in that The input signal includes a sensor signal and a communication signal. The input signal of the required shaft end torque is detected to obtain a detection result, including: Perform fault diagnosis on the sensor signal of the required shaft end torque to obtain the fault diagnosis result; Performing data verification on the communication signal of the required shaft end torque to obtain a data verification result; A detection result is obtained based on the fault diagnosis result and the data verification result.

6. A vehicle shaft end torque control device, It is characterized in that The device comprises: A first calculation module is used to calculate the corresponding unexpected acceleration shaft end torque based on the unexpected acceleration; the unexpected acceleration is an unexpected increase limit of the acceleration; A determination module, configured to determine a coefficient of a power reduction torque mapping relationship based on a ratio between the unexpected acceleration shaft end torque and a maximum required shaft end torque; the maximum required shaft end torque is determined based on an original torque mapping relationship; A second calculation module is used to calculate the corresponding maximum resistance torque according to the preset vehicle speed threshold, and obtain a power reduction torque mapping relationship based on the maximum resistance torque, the coefficient and the original torque mapping relationship; a comparison module, configured to compare the required shaft end torque under different vehicle speed conditions with the required shaft end torque under the power reduction torque mapping relationship at the preset vehicle speed threshold, to obtain a required shaft end torque change value; the required shaft end torque under different vehicle speed conditions is obtained by mapping different vehicle speeds through the original torque mapping relationship; The filtering module is used to filter the switching between the power reduction torque mapping relationship and the original torque mapping relationship when the required shaft end torque change value is not greater than the unexpected acceleration shaft end torque to obtain a filtered power reduction torque mapping relationship.

7. The device according to claim 6, It is characterized in that The device also includes: A processing unit is used to perform slope change processing on the power reduction torque mapping relationship when the required shaft end torque change value is greater than the unexpected acceleration shaft end torque, and filter the switching between the processed power reduction torque mapping relationship and the original torque mapping relationship to obtain a filtered power reduction torque mapping relationship.

8. The device according to claim 6, It is characterized in that The first calculation module also includes: A detection unit, used to detect an input signal of a required shaft end torque and obtain a detection result; The first output unit is used to output the required shaft end torque based on the power reduction torque mapping relationship when the detection result is an input signal failure.

9. A vehicle shaft end torque control device, It is characterized in that The device comprises: Memory for storing computer programs; A processor is used to execute the computer program so that the device performs the vehicle axle end torque control method as claimed in any one of claims 1 to 5.

10. A computer storage medium, It is characterized in that The computer storage medium stores a computer program, and when the computer program is executed by a processor, the method for controlling the vehicle axle end torque according to any one of claims 1 to 5 is implemented.

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