A limp home torque control method and system for new energy vehicles

Abstract

The present invention provides a limp home torque control method and system for a new energy vehicle, comprising: determining a target limit speed of the new energy vehicle according to the vehicle operating state of the new energy vehicle; calculating a limit torque and a speed difference according to the target limit speed; determining the target limit torque of the new energy vehicle based on the limit torque and the speed difference; the present invention divides the calculation of the target limit torque of the vehicle into two steps, first calculating the speed difference between the target limit speed and the current speed, dividing the interval according to the speed difference, and then calculating the target limit torque according to the speed difference interval, which is conducive to refined and flexible control for different speed difference intervals, and performing limp home torque control through different operating states of the new energy vehicle, which is conducive to coping with complex situations, thereby improving the performance of the entire vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and in particular to a limp home torque control method and system for new energy vehicles. Background Art

[0002] At present, new energy vehicles are loved by many consumers because of their good driving quality, easy to realize intelligence, energy saving, environmental protection, low noise and other advantages. An important aspect to measure the power performance of new energy vehicles is their torque control. The limp torque limit of new energy vehicles is a major component of torque control. Its optimization and improvement is of great help to torque control and vehicle performance improvement.

[0003] When the vehicle is in limp mode, the existing limp torque control of new energy commercial vehicles does not consider the impact of other environmental factors on the speed limit, and implements fixed speed and torque limits under all working conditions. This method has the following problems:

[0004] 1. Traditional limp speed control is mostly based on PI regulation. The PI parameter regulation response control amplitude and response rate are fixed values. When the vehicle mass, tires, slope and other conditions are different, the PI regulation parameters vary greatly;

[0005] 2. Under different driving conditions, adopting a single response strategy cannot adapt to complex situations. Summary of the invention

[0006] The present invention provides a limp home torque control method for a new energy vehicle, which is used to solve the problem that the traditional torque limitation is only for a single driving condition and cannot cope with a variety of vehicle operating conditions, including:

[0007] Determining a target speed limit of the new energy vehicle according to the vehicle running state of the new energy vehicle;

[0008] Calculating a limit torque and a vehicle speed difference according to the target limit vehicle speed;

[0009] Based on the limit torque and the vehicle speed difference, a target limit torque of the new energy vehicle is determined.

[0010] Optionally, the vehicle operating status includes: gear status, operating mode, fault speed limit sign, door status and current vehicle speed;

[0011] The limit torque includes: a low limit torque and a high limit torque.

[0012] Optionally, determining the target speed limit of the new energy vehicle according to the vehicle running state of the new energy vehicle includes:

[0013] Determining a first speed limit of the new energy vehicle according to the gear state and the operating mode of the new energy vehicle;

[0014] Determining a second speed limit of the new energy vehicle according to a fault speed limit sign and a door status of the new energy vehicle;

[0015] A target vehicle speed limit of the new energy vehicle is determined according to the first vehicle speed limit and the second vehicle speed limit.

[0016] Optionally, determining the first speed limit of the new energy vehicle according to the gear state and the operation mode of the new energy vehicle includes:

[0017] When the gear state of the new energy vehicle is reverse gear or the operating mode is limp home mode, determining whether the current vehicle speed of the new energy vehicle is less than or equal to the sum of a preset speed limit upper limit value and a reference vehicle speed, and if so, setting the speed limit upper limit value to a first speed limit;

[0018] When the gear state of the new energy vehicle is not reverse gear and the operation mode is not limp home mode, the preset initial vehicle speed limit is set as the first vehicle speed limit.

[0019] Optionally, determining the second speed limit of the new energy vehicle according to the fault speed limit sign and the door status of the new energy vehicle includes:

[0020] When the fault speed limit sign of the new energy vehicle is in an open state or the door state is in an open state, determining whether the current speed of the new energy vehicle is less than or equal to the sum of a preset speed limit lower limit value and the reference speed, and if so, setting the speed limit lower limit value to a second speed limit;

[0021] When the fault speed limit sign of the new energy vehicle is in an off state and the door state is in a closed state, the preset initial speed limit is set as the second speed limit.

[0022] Optionally, determining a target speed limit of the new energy vehicle according to the first speed limit and the second speed limit includes:

[0023] The minimum value of the first vehicle speed limit and the second vehicle speed limit is set as the target vehicle speed limit of the new energy vehicle.

[0024] Optionally, calculating the limit torque according to the target limit vehicle speed includes:

[0025] When the target vehicle speed limit is less than or equal to a preset vehicle speed limit threshold, calculating a low limit torque according to the vehicle speed difference;

[0026] Otherwise, a high limit torque is calculated based on the vehicle speed difference.

[0027] Optionally, calculating the vehicle speed difference according to the target vehicle speed limit includes:

[0028] The vehicle speed difference is a difference between the target vehicle speed limit and the current vehicle speed.

[0029] Optionally, determining the target limit torque of the new energy vehicle based on the limit torque and the vehicle speed difference includes:

[0030] When the vehicle speed difference is within a preset vehicle speed difference threshold range, setting the low limit torque or the high limit torque as a target limit torque;

[0031] Otherwise, the preset initial limit torque is set as the target limit torque.

[0032] Based on the same inventive concept, the present invention also provides a limp home torque control system for a new energy vehicle, comprising:

[0033] The speed limit calculation module is used to determine the target speed limit of the new energy vehicle according to the vehicle running state of the new energy vehicle;

[0034] A state data calculation module: used for calculating the limit torque and the speed difference according to the target limit vehicle speed;

[0035] A torque limit determination module is used to determine a target torque limit of the new energy vehicle based on the torque limit and the vehicle speed difference.

[0036] Optionally, the vehicle running state in the speed limit calculation module includes: gear state, running mode, fault speed limit sign, door state and current vehicle speed;

[0037] The limit torque includes: a low limit torque and a high limit torque.

[0038] Optionally, the speed limit calculation module is specifically used to:

[0039] Determining a first speed limit of the new energy vehicle according to the gear state and the operating mode of the new energy vehicle;

[0040] Determining a second speed limit of the new energy vehicle according to a fault speed limit sign and a door status of the new energy vehicle;

[0041] A target vehicle speed limit of the new energy vehicle is determined according to the first vehicle speed limit and the second vehicle speed limit.

[0042] Optionally, the speed limit calculation module determines the first speed limit of the new energy vehicle according to the gear state and the operation mode of the new energy vehicle, including:

[0043] When the gear state of the new energy vehicle is reverse gear or the operating mode is limp home mode, determining whether the current vehicle speed of the new energy vehicle is less than or equal to the sum of a preset speed limit upper limit value and a reference vehicle speed, and if so, setting the speed limit upper limit value to a first speed limit;

[0044] When the gear state of the new energy vehicle is not reverse gear and the operation mode is not limp home mode, the preset initial vehicle speed limit is set as the first vehicle speed limit.

[0045] Optionally, the speed limit calculation module determines the second speed limit of the new energy vehicle according to the fault speed limit sign and the door status of the new energy vehicle, including:

[0046] When the fault speed limit sign of the new energy vehicle is in an open state or the door state is in an open state, determining whether the current speed of the new energy vehicle is less than or equal to the sum of a preset speed limit lower limit value and the reference speed, and if so, setting the speed limit lower limit value to a second speed limit;

[0047] When the fault speed limit sign of the new energy vehicle is in an off state and the door state is in a closed state, the preset initial speed limit is set as the second speed limit.

[0048] Optionally, the speed limit calculation module determines the target speed limit of the new energy vehicle according to the first speed limit and the second speed limit, including:

[0049] The minimum value of the first vehicle speed limit and the second vehicle speed limit is set as the target vehicle speed limit of the new energy vehicle.

[0050] Optionally, the state data calculation module calculates the limit torque according to the target limit vehicle speed, including:

[0051] When the target vehicle speed limit is less than or equal to a preset vehicle speed limit threshold, calculating a low limit torque according to the vehicle speed difference;

[0052] Otherwise, a high limit torque is calculated based on the vehicle speed difference.

[0053] Optionally, the state data calculation module calculates the vehicle speed difference according to the target vehicle speed limit, including:

[0054] The vehicle speed difference is a difference between the target vehicle speed limit and the current vehicle speed.

[0055] Optionally, the torque limit determination module is specifically used to:

[0056] When the vehicle speed difference is within a preset vehicle speed difference threshold range, setting the low limit torque or the high limit torque as a target limit torque;

[0057] Otherwise, the preset initial limit torque is set as the target limit torque.

[0058] Compared with the closest prior art, the present invention has the following beneficial effects:

[0059] The present invention provides a limp home torque control method and system for a new energy vehicle, comprising: determining a target limit speed of the new energy vehicle according to the vehicle operating state of the new energy vehicle; calculating a limit torque and a speed difference according to the target limit speed; determining the target limit torque of the new energy vehicle based on the limit torque and the speed difference; the present invention divides the calculation of the target limit torque of the vehicle into two steps, first calculating the speed difference between the target limit speed and the current speed, dividing the interval according to the speed difference, and then calculating the target limit torque according to the speed difference interval. The present invention is conducive to refined and flexible control for different speed difference intervals, and performs limp home torque control according to different operating states of the new energy vehicle, which is conducive to coping with complex situations and thus improving the performance of the entire vehicle.

[0060] Other features of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0061] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0063] Figure 1 A schematic flow chart of a limp home torque control method for a new energy vehicle provided by the present invention;

[0064] Figure 2 A schematic diagram of the overall framework of a limp home torque control method for a new energy vehicle provided by the present invention;

[0065] Figure 3 A schematic diagram of the structural composition of a limp home torque control system for a new energy vehicle provided by the present invention. DETAILED DESCRIPTION

[0066] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0067] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. "Multiple" means two or more, unless otherwise clearly and specifically defined. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0068] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0069] Embodiment 1:

[0070] The present invention provides a limp home torque control method for a new energy vehicle, the flow chart of which is as follows: Figure 1 As shown, including:

[0071] Step 1: Determine a target speed limit of the new energy vehicle according to the vehicle running state of the new energy vehicle;

[0072] Step 2: Calculate the limit torque and the speed difference according to the target limit vehicle speed;

[0073] Step 3: Determine the target limit torque of the new energy vehicle based on the limit torque and the vehicle speed difference.

[0074] In one implementation, the process of determining the target speed limit of the new energy vehicle according to the vehicle running state of the new energy vehicle in step 1 above may include:

[0075] Determining a first speed limit of the new energy vehicle according to the gear state and the operating mode of the new energy vehicle;

[0076] Determining a second speed limit of the new energy vehicle according to a fault speed limit sign and a door status of the new energy vehicle;

[0077] A target vehicle speed limit of the new energy vehicle is determined according to the first vehicle speed limit and the second vehicle speed limit.

[0078] For example, the above-mentioned vehicle operation status may include: gear status, operation mode, fault speed limit sign, door status and current vehicle speed; the vehicle operation status is collected by the vehicle controller of the new energy vehicle. In this implementation, the collected vehicle operation status is used as the main condition for limiting the vehicle speed. Based on the gear status, operation mode, fault status and door status of the vehicle, the speed limit can be calculated so that measures can be taken immediately to limit the vehicle speed when a fault or abnormal operation occurs, effectively preventing accidents caused by excessive speed and protecting the safety of drivers and pedestrians. In addition, combined with information such as the door status, such as limiting the speed when the door is not fully closed, it can prompt the driver to pay attention to safety, while reducing the risk of accidental door opening and improving the effectiveness of the overall driving assistance system.

[0079] In this implementation, the process of determining the first speed limit of the new energy vehicle according to the gear state and the operation mode of the new energy vehicle may include:

[0080] When the gear state of the new energy vehicle is reverse gear or the operating mode is limp home mode, determining whether the current vehicle speed of the new energy vehicle is less than or equal to the sum of a preset speed limit upper limit value and a reference vehicle speed, and if so, setting the speed limit upper limit value to a first speed limit;

[0081] When the gear state of the new energy vehicle is not reverse gear and the operating mode is not limp home mode, setting the preset initial speed limit as the first speed limit;

[0082] For example, the process of determining the first speed limit may include:

[0083] If the gear state is reverse gear or the operating mode is limp home mode, the speed limit will not be executed immediately after the condition is met. When it is detected that the current vehicle speed is ≤ the upper limit of the speed limit (for example, represented by a) + the reference speed (for example, set to 3), the first speed limit is determined to be a. Otherwise, the first speed limit is determined to be the default initial speed limit. Preferably, the first speed limit a of this embodiment is set to 15km / h.

[0084] In this implementation, the process of determining the second speed limit of the new energy vehicle according to the fault speed limit sign and the door status of the new energy vehicle may include:

[0085] When the fault speed limit sign of the new energy vehicle is in an open state or the door state is in an open state, determining whether the current speed of the new energy vehicle is less than or equal to the sum of a preset speed limit lower limit value and the reference speed, and if so, setting the speed limit lower limit value to a second speed limit;

[0086] When the fault speed limit sign of the new energy vehicle is in an off state and the door state is in a closed state, setting the preset initial speed limit as a second speed limit;

[0087] For example, the process of determining the second speed limit may include:

[0088] If the fault speed limit sign is in the open state or the door state is in the open state, the speed limit is not immediately executed after the condition is met. When it is detected that the current speed is ≤ the lower limit speed value (for example, represented by b) + the reference speed (for example, set to 3), the second limit speed = b, otherwise the second limit speed = the default initial limit speed. Preferably, the second limit speed b of this embodiment is set to 5km / h.

[0089] In this implementation, the process of determining the target speed limit of the new energy vehicle according to the first speed limit and the second speed limit may include:

[0090] The minimum value of the first speed limit and the second speed limit is set as the target speed limit of the new energy vehicle; that is, the target speed limit can be expressed as: min{first speed limit, second speed limit}.

[0091] In one implementation, the above-mentioned limit torque may include: a low limit torque and a high limit torque.

[0092] In this implementation, the process of calculating the limit torque according to the target limit vehicle speed may include:

[0093] When the target vehicle speed limit is less than or equal to a preset vehicle speed limit threshold, calculating a low limit torque according to the vehicle speed difference;

[0094] Otherwise, a high limit torque is calculated based on the vehicle speed difference.

[0095] Specifically, there are two cases according to the size of the speed limit value. In this embodiment, the target speed limit ≤ 15km / h is classified as the low speed limit, and the target speed limit > 15km / h is classified as the high speed limit. A series of speed difference intervals are obtained based on the speed difference between the target speed limit and the current speed, where the speed difference = target speed limit - current speed, and both the target speed limit and the current speed are integers. Based on experience and repeated experiments, different torque limit calculation formulas are used in different speed difference intervals. The calculation formula for the low torque limit in this embodiment is as follows:

[0096] When the speed difference is < 0,

[0097] When the vehicle speed difference = 0,

[0098] When the vehicle speed difference = 1,

[0099] When the speed difference = 2,

[0100] When the speed difference = 3,

[0101] When the speed difference = 4,

[0102] When the speed difference = 5,

[0103] Wherein, T0 represents the default initial limit torque; p0 and p1 are calibrated empirical values, preferably, p0=10, p1=20;

[0104] The calculation formula for the low limiting torque is as follows:

[0105] When the speed difference is < 0,

[0106] When the vehicle speed difference = 0,

[0107] When the vehicle speed difference = 1,

[0108] When the speed difference = 2,

[0109] When the speed difference = 3,

[0110] When the speed difference = 4,

[0111] When the speed difference = 5,

[0112] Wherein, T0 represents the default initial limit torque; p0 and p1 are calibrated empirical values, preferably, p0=20, p1=10;

[0113] In this implementation, the above-mentioned calculation of the vehicle speed difference according to the target vehicle speed limit includes:

[0114] The vehicle speed difference is a difference between the target vehicle speed limit and the current vehicle speed.

[0115] In the above step 3, the process of determining the target limit torque of the new energy vehicle based on the limit torque and the vehicle speed difference may include:

[0116] When the vehicle speed difference is within a preset vehicle speed difference threshold range, setting the low limit torque or the high limit torque as a target limit torque;

[0117] Otherwise, the preset initial limit torque is set as the target limit torque.

[0118] For example, the process of determining the target limit torque may include: in the case of a low limit vehicle speed, combining the size of the vehicle speed difference, outputting the low limit torque T qlow In the case of high speed limit, combined with the speed difference, the high limit torque T is output qhigh Finally, determine whether the speed difference is between -3km / h and 5km / h. If -3km / h≤speed difference≤5km / h, the output target limit torque = low limit torque T qlow Or high limit torque T qhigh If the vehicle speed difference is <-3km / h or the vehicle speed difference is >5km / h, the output target limit torque = the default initial limit torque T0.

[0119] The present invention proposes a limp torque control method for a new energy vehicle, and the overall framework diagram is shown in FIG. Figure 2 As shown, the target limit torque calculation of the vehicle is completed in two steps. First, the speed difference between the target limit speed and the current speed is calculated, and the interval is divided according to the speed difference. Then, the target limit torque is calculated according to the speed difference interval, which is conducive to refined and flexible control for different speed difference intervals. When calculating the target limit speed, the current speed, gear state and fault state are detected by the vehicle controller, and the door state sent by the body controller is received through the CAN bus. When the vehicle fails, the door is opened or enters the limp mode, the speed limit is executed, the target limit speed is calculated, and the difference between the target limit speed and the current speed is divided into intervals. In different difference intervals, different calculation formulas are used on the basis of the motor torque limit to obtain the corresponding limp torque. The present invention is based on a similar PI adjustment idea, formulates a fixed parameter value control adjustment, achieves the purpose of precise control, and solves the problem of other factors such as load, working conditions, and tires affecting the changes in vehicle parameters.

[0120] Embodiment 2:

[0121] The present invention provides a limp home torque control system for a new energy vehicle, the structural composition diagram of which is shown in FIG. Figure 3 As shown, including:

[0122] The speed limit calculation module is used to determine the target speed limit of the new energy vehicle according to the vehicle running state of the new energy vehicle;

[0123] A state data calculation module: used for calculating the limit torque and the speed difference according to the target limit vehicle speed;

[0124] A torque limit determination module is used to determine a target torque limit of the new energy vehicle based on the torque limit and the vehicle speed difference.

[0125] For example, the vehicle running state in the above-mentioned speed limit calculation module may include: gear state, running mode, fault speed limit sign, door state and current vehicle speed;

[0126] The above-mentioned limit torque may include: a low limit torque and a high limit torque.

[0127] The above-mentioned speed limit calculation module is specifically used for:

[0128] Determining a first speed limit of the new energy vehicle according to the gear state and the operating mode of the new energy vehicle;

[0129] Determining a second speed limit of the new energy vehicle according to a fault speed limit sign and a door status of the new energy vehicle;

[0130] A target vehicle speed limit of the new energy vehicle is determined according to the first vehicle speed limit and the second vehicle speed limit.

[0131] The process of determining the first speed limit of the new energy vehicle according to the gear state and the operation mode of the new energy vehicle in the above-mentioned speed limit calculation module may include:

[0132] When the gear state of the new energy vehicle is reverse gear or the operating mode is limp home mode, determining whether the current vehicle speed of the new energy vehicle is less than or equal to the sum of a preset speed limit upper limit value and a reference vehicle speed, and if so, setting the speed limit upper limit value to a first speed limit;

[0133] When the gear state of the new energy vehicle is not reverse gear and the operation mode is not limp home mode, the preset initial vehicle speed limit is set as the first vehicle speed limit.

[0134] The process of determining the second speed limit of the new energy vehicle according to the fault speed limit sign and the door status of the new energy vehicle in the above-mentioned speed limit calculation module may include:

[0135] When the fault speed limit sign of the new energy vehicle is in an open state or the door state is in an open state, determining whether the current speed of the new energy vehicle is less than or equal to the sum of a preset speed limit lower limit value and the reference speed, and if so, setting the speed limit lower limit value to a second speed limit;

[0136] When the fault speed limit sign of the new energy vehicle is in an off state and the door state is in a closed state, the preset initial speed limit is set as the second speed limit.

[0137] The process of determining the target speed limit of the new energy vehicle according to the first speed limit and the second speed limit in the above-mentioned speed limit calculation module may include:

[0138] The minimum value of the first vehicle speed limit and the second vehicle speed limit is set as the target vehicle speed limit of the new energy vehicle.

[0139] The process of calculating the limit torque according to the target limit vehicle speed in the above-mentioned state data calculation module may include:

[0140] When the target vehicle speed limit is less than or equal to a preset vehicle speed limit threshold, calculating a low limit torque according to the vehicle speed difference;

[0141] Otherwise, a high limit torque is calculated based on the vehicle speed difference.

[0142] The process of calculating the vehicle speed difference according to the target vehicle speed limit in the above-mentioned state data calculation module may include:

[0143] The vehicle speed difference is a difference between the target vehicle speed limit and the current vehicle speed.

[0144] The above-mentioned limit torque determination module is specifically used for:

[0145] When the vehicle speed difference is within a preset vehicle speed difference threshold range, setting the low limit torque or the high limit torque as a target limit torque;

[0146] Otherwise, the preset initial limit torque is set as the target limit torque.

[0147] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0148] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0149] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0150] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0151] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A limp home torque control method for a new energy vehicle, characterized in that: include: Determining a target speed limit of the new energy vehicle according to the vehicle running state of the new energy vehicle; Calculating a limit torque and a vehicle speed difference according to the target limit vehicle speed; Determining a target limit torque of the new energy vehicle based on the limit torque and the vehicle speed difference; The vehicle operation status includes: gear status, operation mode, fault speed limit sign, door status and current vehicle speed; The limiting torque includes: a low limiting torque and a high limiting torque; Calculating the limit torque according to the target limit vehicle speed includes: When the target vehicle speed limit is less than or equal to a preset vehicle speed limit threshold, calculating a low limit torque according to the vehicle speed difference; otherwise, calculating a high limit torque according to the vehicle speed difference; The expression corresponding to the low limit torque is as follows: When the speed difference is < 0, When the vehicle speed difference = 0, When the vehicle speed difference = 1, When the speed difference = 2, When the speed difference = 3, When the speed difference = 4, When the speed difference = 5, The expression corresponding to the high limit torque is as follows: When the speed difference is < 0, When the vehicle speed difference = 0, When the vehicle speed difference = 1, When the speed difference = 2, When the speed difference = 3, When the speed difference = 4, When the speed difference = 5, Where, T0 represents the default initial limit torque; T qlow Indicates low limit torque; T qhigh Indicates high limit torque; p0 is the first preset empirical value; p1 is the second preset empirical value.

2. The method according to claim 1, characterized in that Determining the target speed limit of the new energy vehicle according to the vehicle running state of the new energy vehicle includes: Determining a first speed limit of the new energy vehicle according to the gear state and the operating mode of the new energy vehicle; Determining a second speed limit of the new energy vehicle according to a fault speed limit sign and a door status of the new energy vehicle; A target vehicle speed limit of the new energy vehicle is determined according to the first vehicle speed limit and the second vehicle speed limit.

3. The method according to claim 2, characterized in that The step of determining a first speed limit of the new energy vehicle according to the gear state and the operation mode of the new energy vehicle comprises: When the gear state of the new energy vehicle is reverse gear or the operating mode is limp home mode, determining whether the current speed of the new energy vehicle is less than or equal to the sum of a preset speed limit upper limit value and a reference speed, and if so, setting the speed limit upper limit value to a first speed limit; When the gear state of the new energy vehicle is not reverse gear and the operation mode is not limp home mode, the preset initial vehicle speed limit is set as the first vehicle speed limit.

4. The method according to claim 3, characterized in that The determining the second speed limit of the new energy vehicle according to the fault speed limit sign and the door status of the new energy vehicle comprises: When the fault speed limit mark of the new energy vehicle is in an open state or the door state is in an open state, determining whether the current speed of the new energy vehicle is less than or equal to the sum of a preset speed limit lower limit value and the reference speed, and if so, setting the speed limit lower limit value to a second speed limit; When the fault speed limit sign of the new energy vehicle is in an off state and the door state is in a closed state, the preset initial speed limit is set as the second speed limit.

5. The method according to claim 2, characterized in that The step of determining a target speed limit of the new energy vehicle according to the first speed limit and the second speed limit includes: The minimum value of the first vehicle speed limit and the second vehicle speed limit is set as the target vehicle speed limit of the new energy vehicle.

6. The method according to claim 1, characterized in that Calculating the vehicle speed difference according to the target vehicle speed limit includes: The vehicle speed difference is a difference between the target vehicle speed limit and the current vehicle speed.

7. The method according to claim 6, characterized in that The determining the target limit torque of the new energy vehicle based on the limit torque and the vehicle speed difference includes: When the vehicle speed difference is within a preset vehicle speed difference threshold range, setting the low limit torque or the high limit torque as a target limit torque; Otherwise, the preset initial limit torque is set as the target limit torque.

8. A limp home torque control system for a new energy vehicle, characterized in that: include: The speed limit calculation module is used to determine the target speed limit of the new energy vehicle according to the vehicle running state of the new energy vehicle; A state data calculation module: used for calculating the limit torque and the speed difference according to the target limit vehicle speed; A torque limit determination module: used for determining a target torque limit of the new energy vehicle based on the torque limit and the vehicle speed difference; The vehicle operation status includes: gear status, operation mode, fault speed limit sign, door status and current vehicle speed; The limiting torque includes: a low limiting torque and a high limiting torque; The state data calculation module comprises: When the target vehicle speed limit is less than or equal to a preset vehicle speed limit threshold, calculating a low limit torque according to the vehicle speed difference; otherwise, calculating a high limit torque according to the vehicle speed difference; The expression corresponding to the low limit torque is as follows: When the speed difference is < 0, When the vehicle speed difference = 0, When the vehicle speed difference = 1, When the speed difference = 2, When the speed difference = 3, When the speed difference = 4, When the speed difference = 5, The expression corresponding to the high limit torque is as follows: When the speed difference is < 0, When the vehicle speed difference = 0, When the vehicle speed difference = 1, When the speed difference = 2, When the speed difference = 3, When the speed difference = 4, When the speed difference = 5, Where, T0 represents the default initial limit torque; T qlow Indicates low limit torque; T qhigh Indicates high limit torque; p0 is the first preset empirical value; p1 is the second preset empirical value.

Images