A torque control method, device, equipment and medium for coasting switching to crawling

Abstract

The application discloses a torque control method, device and equipment for switching from coasting to crawling, and a medium. The method comprises the following steps: constructing a theoretical deceleration reference curve of a vehicle when the vehicle is running on a flat road based on a preset vehicle load gradient; acquiring a vehicle deceleration curve in a preset time interval when the vehicle coasting speed is lower than a preset threshold, and determining a theoretical coasting curve of the vehicle based on the vehicle deceleration curve and the theoretical deceleration reference curve; generating a predicted coasting curve by a preset coasting curve prediction algorithm based on the vehicle deceleration curve; determining a theoretical coasting deceleration based on the theoretical coasting curve, and determining a predicted coasting deceleration based on the predicted coasting curve; and calculating a preset torque for crawling in a current working condition based on the theoretical coasting deceleration and the predicted coasting deceleration. The application realizes accurate calculation of the torque required for maintaining crawling through the above method, so that the vehicle can be prevented from shaking due to large torque change when entering the crawling state.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of electric vehicles, in particular to a torque control method, device and equipment for switching from coasting to crawling and a medium. BACKGROUND

[0002] Coasting: during the whole vehicle driving process, the vehicle continues to drive without the help of power and only relies on its own kinetic energy (or inertia). Crawling: low-speed cruise driving assistance, the vehicle automatically controls the power output to maintain a low vehicle speed, and the driver only needs to control the steering wheel without operating the accelerator and brake to complete stable driving.

[0003] Since the crawling mode adopts closed-loop control based on vehicle speed, the motor torque control during normal driving is open-loop control. In the known vehicle weight condition, when the vehicle enters the crawling mode from the coasting state, the crawling torque calculated according to the simple PID algorithm may have the problems of serious vehicle speed overshoot or large torque fluctuation. Since the deceleration curve of the vehicle under the conditions of empty load, half load and full load on a flat road can be obtained in the whole vehicle verification stage, the coasting curve on a flat road under the current load can be calculated according to the current vehicle weight. However, on the actual road, the road conditions are extremely complex, and the road slope and road roughness change in real time. Therefore, how to accurately calculate the torque required to maintain the crawling becomes a technical problem to be solved, so as to avoid the large torque change of the vehicle when entering the crawling and cause the whole vehicle to shake. SUMMARY

[0004] The embodiments of the application provide a torque control method, device, equipment and medium for switching from coasting to crawling, to solve the technical problem of how to accurately calculate the torque required to maintain the crawling, so as to avoid the large torque change of the vehicle when entering the crawling and cause the whole vehicle to shake.

[0005] In a first aspect, the embodiments of the application provide a torque control method for switching from coasting to crawling, characterized in that the method comprises: constructing a theoretical deceleration reference curve of a vehicle driving on a flat road based on a preset vehicle load gradient; acquiring a vehicle deceleration curve in a preset time interval when the vehicle coasting speed is lower than a preset threshold, and determining a theoretical coasting curve of the vehicle based on the vehicle deceleration curve and the theoretical deceleration reference curve; generating a predicted coasting curve by a preset coasting curve prediction algorithm based on the vehicle deceleration curve; determining a theoretical coasting deceleration based on the theoretical coasting curve, and determining a predicted coasting deceleration based on the predicted coasting curve; and calculating a crawling preset torque under the current working condition based on the theoretical coasting deceleration and the predicted coasting deceleration.

[0006] In an implementation form of the application, the crawling preset torque under the current working condition is calculated based on the theoretical coasting deceleration and the predicted coasting deceleration, specifically comprising: calculating the theoretical crawling demand torque of the vehicle through a vehicle dynamics formula; determining the theoretical deviation coefficient of the vehicle based on the predicted coasting deceleration and the theoretical coasting deceleration; correcting the theoretical crawling demand torque based on the theoretical deviation coefficient to determine the crawling preset torque under the current working condition.

[0007] In an implementation form of the application, the theoretical deviation coefficient of the vehicle is determined based on the predicted coasting deceleration and the theoretical coasting deceleration, specifically comprising: determining a deceleration difference value of the theoretical coasting deceleration and the predicted coasting deceleration, and determining a deceleration ratio value of the deceleration difference value and the theoretical coasting deceleration; determining the theoretical deviation coefficient of the vehicle according to an association relationship between the deceleration ratio and the theoretical deviation coefficient; wherein the sum of the deceleration ratio and the theoretical deviation coefficient is a unit number.

[0008] In an implementation form of the application, after the crawling preset torque under the current working condition is determined, the method further comprises: determining whether the crawling preset torque is greater than the maximum braking torque of the drive system or less than the minimum braking torque; in the case that the crawling preset torque is determined to be not greater than the maximum braking torque of the drive system and not less than the minimum braking torque, outputting the crawling preset torque; in the case that the crawling preset torque is determined to be greater than the maximum braking torque of the drive system, outputting the maximum braking torque; in the case that the crawling preset torque is determined to be less than the minimum braking torque of the drive system, outputting the minimum braking torque.

[0009] In an implementation form of the application, the theoretical deceleration reference curve of the vehicle driving on a flat road is constructed based on a preset vehicle load gradient, specifically comprising: determining a vehicle to be tested based on the vehicle load gradient, and performing a coasting test on the vehicle to be tested based on a preset flat road; obtaining a coasting speed of the vehicle to be tested, and generating the theoretical deceleration reference curve of the vehicle driving on the flat road based on the coasting speed.

[0010] In an implementation form of the application, the theoretical coasting curve of the vehicle is determined based on the vehicle deceleration curve and the theoretical deceleration reference curve, specifically comprising: determining an average deceleration of the vehicle in a preset time interval based on a starting speed and an ending speed of the vehicle deceleration curve; determining a theoretical load of the vehicle based on the average deceleration and the theoretical deceleration reference curve of the vehicle; determining the theoretical coasting curve of the vehicle based on the theoretical load of the vehicle.

[0011] In an implementation form of the present application, before the predicted coasting curve is generated by the preset coasting curve prediction algorithm based on the vehicle deceleration curve, the method further comprises: obtaining sample vehicle deceleration curves of a plurality of vehicles under different working conditions when the vehicle coasting speed is lower than a preset threshold and within a preset time interval, and obtaining complete sample vehicle deceleration curves corresponding to the plurality of vehicles; and training the preset coasting curve prediction algorithm based on the sample vehicle deceleration curves and the complete sample vehicle deceleration curves until the training converges.

[0012] In a second aspect, the embodiments of the present application further provide a torque control device for coasting switching to crawling, which comprises a construction module, an acquisition module, a generation module, a determination module and a calculation module. The construction module is configured to construct a theoretical deceleration reference curve of a vehicle driving on a flat road based on a preset vehicle load gradient. The acquisition module is configured to acquire a vehicle deceleration curve within a preset time interval when the vehicle coasting speed is lower than a preset threshold, and determine a theoretical coasting curve of the vehicle based on the vehicle deceleration curve and the theoretical deceleration reference curve. The generation module is configured to generate a predicted coasting curve based on the vehicle deceleration curve by a preset coasting curve prediction algorithm. The determination module is configured to determine a theoretical coasting deceleration based on the theoretical coasting curve, and determine a predicted coasting deceleration based on the predicted coasting curve. The calculation module is configured to calculate a preset crawling torque under a current working condition based on the theoretical coasting deceleration and the predicted coasting deceleration.

[0013] In a third aspect, the embodiments of the present application further provide a torque control device for coasting switching to crawling, which comprises at least one processor and a memory communicatively connected to the at least one processor. The memory stores instructions executable by the at least one processor. The instructions are executed by the at least one processor to enable the at least one processor to: construct a theoretical deceleration reference curve of a vehicle driving on a flat road based on a preset vehicle load gradient; acquire a vehicle deceleration curve within a preset time interval when the vehicle coasting speed is lower than a preset threshold, and determine a theoretical coasting curve of the vehicle based on the vehicle deceleration curve and the theoretical deceleration reference curve; generate a predicted coasting curve based on the vehicle deceleration curve by a preset coasting curve prediction algorithm; determine a theoretical coasting deceleration based on the theoretical coasting curve, and determine a predicted coasting deceleration based on the predicted coasting curve; and calculate a preset crawling torque under a current working condition based on the theoretical coasting deceleration and the predicted coasting deceleration.

[0014] In a fourth aspect, the embodiments of the present application further provide a non-volatile computer storage medium for torque control of coasting switching to crawling, which stores computer executable instructions, and the computer executable instructions are configured to: construct a theoretical deceleration reference curve of a vehicle when the vehicle travels on a flat road based on a preset vehicle load gradient; acquire a vehicle deceleration curve in a preset time interval when a coasting speed of the vehicle is lower than a preset threshold, and determine a theoretical coasting curve of the vehicle based on the vehicle deceleration curve and the theoretical deceleration reference curve; generate a predicted coasting curve based on the vehicle deceleration curve and a preset coasting curve prediction algorithm; determine a theoretical coasting deceleration based on the theoretical coasting curve, and determine a predicted coasting deceleration based on the predicted coasting curve; and calculate a preset crawling torque in a current working condition based on the theoretical coasting deceleration and the predicted coasting deceleration.

[0015] The torque control method, device, equipment and medium provided by the embodiments of the present application can obtain a theoretical coasting deceleration through a theoretical deceleration reference curve, predict a coasting deceleration through a coasting direction prediction algorithm, and calculate a preset crawling torque in a current working condition according to the obtained theoretical coasting deceleration and the predicted predicted coasting deceleration. Through the above method, the coasting curve and other related data information can be obtained in the test stage of a sample vehicle, and calibration and application are relatively convenient. Moreover, the current working condition can be identified, and the preset torque when coasting switches to crawling can be corrected. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which are included to provide a further understanding of the present application and constitute a part of this application, illustrate certain illustrative embodiments of the present application and together with the description serve to explain the present application. In the drawings:

[0017] Figure 1 A flowchart of a torque control method of coasting switching to crawling is provided for the embodiments of the present application;

[0018] Figure 2 A structure schematic diagram of a torque control device of coasting switching to crawling is provided for the embodiments of the present application;

[0019] Figure 3 An internal structure schematic diagram of a torque control device of coasting switching to crawling is provided for the embodiments of the present application. DETAILED DESCRIPTION

[0020] In order to make the purposes, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described below in connection with specific embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0021] The embodiments of the present application provide a torque control method, device, equipment and medium for coasting to crawling, to solve the technical problem of how to accurately calculate the torque required to maintain crawling to avoid large torque changes when the vehicle enters crawling, which leads to vehicle shaking.

[0022] The technical solutions provided by the embodiments of the present application will be described in detail below with reference to the drawings.

[0023] Figure 1 A flowchart of a torque control method for coasting to crawling is provided in the embodiments of the present application. As shown in Figure 1 The torque control method for coasting to crawling provided by the embodiments of the present application specifically includes the following steps:

[0024] Step 101, based on a preset vehicle load gradient, a theoretical deceleration reference curve of the vehicle driving on a flat road is constructed.

[0025] In an embodiment of the present application, in order to accurately calculate the torque required to maintain crawling to avoid large torque changes when the vehicle enters crawling, which leads to vehicle shaking, first, based on a preset vehicle load gradient, a theoretical deceleration reference curve of the vehicle driving on a flat road is constructed.

[0026] Specifically, based on the vehicle load gradient, a vehicle to be tested is determined, and the vehicle to be tested is tested based on a preset flat road; the coasting speed of the vehicle to be tested is obtained, and the theoretical deceleration reference curve of the vehicle driving on a flat road is generated based on the coasting speed.

[0027] In an embodiment of the present application, the vehicle dynamics formula is represented by the following formula:

[0028]

[0029] Wherein, T TM is the motor torque, i g is the gear ratio of the gearbox, i0 is the rear axle ratio, η is the transmission system efficiency, r is the tire rolling radius, C DC d is the vehicle's wind resistance coefficient, A is the vehicle's frontal area, m is the vehicle's weight, g is the acceleration of gravity, f is the road rolling coefficient, i is the road slope, v is the vehicle's speed, a is the vehicle's acceleration, and δ is the vehicle's rotational mass conversion coefficient.

[0030] Step 102, in the case where the vehicle's sliding speed is lower than a preset threshold, a vehicle deceleration curve in a preset time interval is obtained, and a theoretical sliding curve of the vehicle is determined based on the vehicle deceleration curve and a theoretical deceleration reference curve.

[0031] In an embodiment of the present application, in the case where the vehicle's sliding speed is lower than a preset threshold, a vehicle deceleration curve in a preset time interval is first obtained according to a speed sensor arranged on the vehicle. The preferred preset time interval is 5 s.

[0032] Further, the theoretical sliding curve of the vehicle is determined based on the vehicle deceleration curve and a theoretical deceleration reference curve.

[0033] Specifically, the average deceleration of the vehicle in the preset time interval is determined based on the starting speed and the ending speed of the vehicle deceleration curve; the theoretical load of the vehicle is determined based on the average deceleration and the theoretical deceleration reference curve of the vehicle; and the theoretical sliding curve of the vehicle is determined based on the theoretical load of the vehicle.

[0034] Step 103, a predicted sliding curve is generated based on the vehicle deceleration curve and a preset sliding curve prediction algorithm.

[0035] In an embodiment of the present application, after obtaining the vehicle deceleration curve in the preset time interval, a predicted sliding curve is generated based on the vehicle deceleration curve and a preset sliding curve prediction algorithm.

[0036] In an embodiment of the present application, before generating the predicted sliding curve based on the vehicle deceleration curve and a preset sliding curve prediction algorithm, the method further comprises: obtaining sample vehicle deceleration curves of vehicles with different loads under different road conditions in a preset time interval when the vehicle's sliding speed is lower than a preset threshold, and obtaining complete sample vehicle deceleration curves corresponding to the vehicles with different loads; and training the preset sliding curve prediction algorithm based on the sample vehicle deceleration curves and the complete sample vehicle deceleration curves until the training converges.

[0037] Step 104, a theoretical sliding deceleration is determined based on the theoretical sliding curve, and a predicted sliding deceleration is determined based on the predicted sliding curve.

[0038] In an embodiment of the present application, after obtaining the theoretical sliding curve and the predicted sliding curve, a theoretical sliding deceleration is determined based on the theoretical sliding curve, and a predicted sliding deceleration is determined based on the predicted sliding curve.

[0039] Step 105, calculating the creep preset torque under the current working condition based on the theoretical coasting deceleration and the predicted coasting deceleration.

[0040] In an embodiment of the present application, after determining the theoretical coasting deceleration and the predicted coasting deceleration, the creep preset torque under the current working condition is calculated based on the theoretical coasting deceleration and the predicted coasting deceleration

[0041] Specifically, the theoretical creep demand torque of the vehicle is calculated through a vehicle dynamics formula; the theoretical deviation coefficient of the vehicle is determined based on the predicted coasting deceleration and the theoretical coasting deceleration; and the theoretical creep demand torque is corrected based on the theoretical deviation coefficient to determine the creep preset torque under the current working condition.

[0042] In an embodiment of the present application, the theoretical deviation coefficient of the vehicle is determined based on the predicted coasting deceleration and the theoretical coasting deceleration, specifically including: determining a deceleration difference value of the theoretical coasting deceleration and the predicted coasting deceleration, and determining a deceleration ratio value of the deceleration difference value and the theoretical coasting deceleration; determining the theoretical deviation coefficient of the vehicle according to an association relationship between the deceleration ratio and the theoretical deviation coefficient; and wherein the sum of the deceleration ratio and the theoretical deviation coefficient is a unit number.

[0043] In an embodiment of the present application, after determining the creep preset torque under the current working condition, the method further includes: determining whether the creep preset torque is greater than the maximum braking torque of the drive system or less than the minimum braking torque; outputting the creep preset torque in the case of determining that the creep preset torque is not greater than the maximum braking torque of the drive system and not less than the minimum braking torque; outputting the maximum braking torque in the case of determining that the creep preset torque is greater than the maximum braking torque of the drive system; and outputting the minimum braking torque in the case of determining that the creep preset torque is less than the minimum braking torque of the drive system.

[0044] The above is a method embodiment provided by the present application. Based on the same inventive concept, the present application embodiment also provides a torque control device for coasting switching to creeping, the structure of which is shown in Figure 2 .

[0045] Figure 2 A torque control device for coasting switching to creeping provided by an embodiment of the present application is shown in Figure 2 . As shown, the device includes a construction module 201, an acquisition module 202, a generation module 203, a determination module 204, and a calculation module 205.

[0046] In an embodiment of the present application, the construction module 201 is configured to construct a theoretical deceleration reference curve of the vehicle when the vehicle travels on a flat road based on a preset vehicle load gradient; the acquisition module 202 is configured to acquire a vehicle deceleration curve in a preset time interval when the vehicle coasting speed is lower than a preset threshold, and determine a theoretical coasting curve of the vehicle based on the vehicle deceleration curve and the theoretical deceleration reference curve; the generation module 203 is configured to generate a predicted coasting curve based on the vehicle deceleration curve by using a preset coasting curve prediction algorithm; the determination module 204 is configured to determine a theoretical coasting deceleration based on the theoretical coasting curve, and determine a predicted coasting deceleration based on the predicted coasting curve; and the calculation module 205 is configured to calculate the preset creep torque under the current working condition based on the theoretical coasting deceleration and the predicted coasting deceleration.

[0047] The above is a method embodiment of the present application. Based on the same inventive concept, the embodiment of the present application also provides a torque control device for switching from coasting to creeping, and a structure thereof is shown in Figure 3 .

[0048] Figure 3 A torque control device for switching from coasting to creeping provided by the embodiment of the present application is shown in Figure 3 .

[0049] at least one processor 301;

[0050] and a memory 302 in communication connection with the at least one processor;

[0051] The memory 302 stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor 301 to enable the at least one processor 301 to:

[0052] construct a theoretical deceleration reference curve of the vehicle when the vehicle travels on a flat road based on a preset vehicle load gradient;

[0053] acquire a vehicle deceleration curve in a preset time interval when the vehicle coasting speed is lower than a preset threshold, and determine a theoretical coasting curve of the vehicle based on the vehicle deceleration curve and the theoretical deceleration reference curve;

[0054] generate a predicted coasting curve based on the vehicle deceleration curve by using a preset coasting curve prediction algorithm;

[0055] determine a theoretical coasting deceleration based on the theoretical coasting curve, and determine a predicted coasting deceleration based on the predicted coasting curve;

[0056] calculate the preset creep torque under the current working condition based on the theoretical coasting deceleration and the predicted coasting deceleration.

[0057] Some embodiments of the present application provide a non-volatile computer storage medium corresponding to Figure 1 a torque control for coasting to crawling switching, storing computer executable instructions, the computer executable instructions being arranged to:

[0058] construct a theoretical deceleration reference curve of the vehicle when driving on a flat road based on a preset vehicle load gradient;

[0059] in a case where the vehicle coasting speed is lower than a preset threshold, acquire a vehicle deceleration curve in a preset time interval, and determine a theoretical coasting curve of the vehicle based on the vehicle deceleration curve and the theoretical deceleration reference curve;

[0060] generate a predicted coasting curve based on the vehicle deceleration curve and a preset coasting curve prediction algorithm;

[0061] determine a theoretical coasting deceleration based on the theoretical coasting curve, and determine a predicted coasting deceleration based on the predicted coasting curve;

[0062] calculate a crawling preset torque in a current working condition based on the theoretical coasting deceleration and the predicted coasting deceleration.

[0063] In the 1990s, it was quite obvious to distinguish whether an improvement in a technology was in hardware (e.g., improvement in circuit structures of diodes, transistors, switches, etc.) or in software (improvement in method flow). However, as technology has evolved, many improvements in method flow today can be considered as direct improvements in hardware circuit structures. Designers almost always obtain the corresponding hardware circuit structures by programming the improved method flow into hardware circuits. Therefore, it cannot be said that an improvement in a method flow cannot be implemented by hardware entity modules. For example, a programmable logic device (PLD) (e.g., a field programmable gate array (FPGA)) is an integrated circuit whose logic function is determined by user programming of the device. A digital system is "integrated" on a PLD by the designer programming it, rather than by asking a chip manufacturer to design and fabricate a custom integrated circuit chip. Moreover, instead of manually fabricating integrated circuit chips, this programming is now mostly implemented by "logic compiler" software, which is similar to software compilers used in program development, and the original code to be compiled is written in a specific programming language, which is called a hardware description language (HDL), and there are many such languages, such as ABEL (Advanced Boolean Expression Language), AHDL (Altera Hardware Description Language), Confluence, CUPL (Cornell University Programming Language), HDCal, JHDL (Java Hardware Description Language), Lava, Lola, MyHDL, PALASM, RHDL (Ruby Hardware Description Language), etc., and the most commonly used are VHDL (Very-High-Speed Integrated Circuit Hardware Description Language) and Verilog. Those skilled in the art should be aware that, as long as the method flow is logically programmed in the above-mentioned hardware description languages and programmed into an integrated circuit, a hardware circuit implementing the logical method flow can be easily obtained.

[0064] The controller can be implemented in any suitable manner. For example, it can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers. Examples of controllers include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicon Labs C8051F320. A memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art will also recognize that, in addition to implementing the controller in purely computer-readable program code form, the same functionality can be achieved by logically programming the method steps to make the controller take the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers. Therefore, such a controller can be considered a hardware component, and the means included therein for implementing various functions can also be considered as structures within the hardware component. Alternatively, the means for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0065] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, a computer can be, for example, a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email device, game console, tablet computer, wearable device, or any combination of these devices.

[0066] For ease of description, the above devices are described in terms of function, divided into various units. Of course, in implementing this specification, the functions of each unit can be implemented in one or more software and / or hardware components.

[0067] Those skilled in the art will understand that the embodiments of this specification can be provided as methods, systems, or computer program products. Therefore, the embodiments of this specification can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the embodiments of this specification can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0068] This specification is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this specification. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0069] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0070] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0071] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0072] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0073] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0074] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0075] This specification can be described in the general context of computer-executable instructions that are executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform a specific task or implement a specific abstract data type. This specification can also be practiced in distributed computing environments, where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0076] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the embodiments of apparatus, devices, and non-volatile computer storage media are basically similar to the method embodiments, so the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0077] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0078] The above description is merely one or more embodiments of this specification and is not intended to limit this specification. Various modifications and variations can be made to the one or more embodiments of this specification by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of one or more embodiments of this specification should be included within the scope of the claims of this specification.

Claims

1. A torque control method for switching from coasting to creeping, characterized in that, The method includes: Based on the preset vehicle load gradient, a theoretical deceleration reference curve is constructed for the vehicle when it is traveling on a straight road. When the vehicle's coasting speed is lower than a preset threshold, the vehicle deceleration curve at a preset time interval is obtained, and the theoretical coasting curve of the vehicle is determined based on the vehicle deceleration curve and the theoretical deceleration reference curve. Based on the vehicle deceleration curve, a predicted slip curve is generated using a preset slip curve prediction algorithm; Based on the theoretical gliding curve, the theoretical gliding deceleration is determined, and based on the predicted gliding curve, the predicted gliding deceleration is determined. The creep preset torque under the current operating condition is calculated based on the theoretical and predicted gliding deceleration.

2. The torque control method for switching from coasting to creeping according to claim 1, characterized in that, The calculation of the preset creep torque under the current operating condition based on the theoretical coasting deceleration and the predicted coasting deceleration specifically includes: The theoretical creep torque requirement of the vehicle is calculated using vehicle dynamics formulas. Based on the predicted coasting deceleration and the theoretical coasting deceleration, the theoretical deviation coefficient of the vehicle is determined; Based on the theoretical deviation coefficient, the theoretical creeping torque requirement is corrected to determine the preset creeping torque under the current working conditions.

3. The torque control method for switching from coasting to creeping according to claim 2, characterized in that, Based on the predicted coasting deceleration and the theoretical coasting deceleration, the theoretical deviation coefficient of the vehicle is determined, specifically including: Determine the deceleration difference between the theoretical deceleration and the predicted deceleration, and determine the deceleration ratio between the deceleration difference and the theoretical deceleration; The theoretical deviation coefficient of the vehicle is determined based on the correlation between the deceleration ratio and the theoretical deviation coefficient; wherein the sum of the deceleration ratio and the theoretical deviation coefficient is a single unit.

4. The torque control method for switching from coasting to creeping according to claim 2, characterized in that, After determining the preset creep torque under the current operating conditions, the method further includes: Determine whether the creeping preset torque is greater than the maximum braking torque of the drive system or less than the minimum braking torque; If the creep preset torque is determined to be no greater than the maximum braking torque of the drive system and no less than the minimum braking torque, the creep preset torque is output. If the creep preset torque is determined to be greater than the maximum braking torque of the drive system, the maximum braking torque is output. If the creep preset torque is determined to be less than the minimum braking torque of the drive system, the minimum braking torque is output.

5. The torque control method for switching from coasting to creeping according to claim 1, characterized in that, Based on a preset vehicle load gradient, a theoretical deceleration reference curve is constructed for the vehicle traveling on a straight road, specifically including: Based on the vehicle load gradient, the vehicle to be tested is determined, and a skidding test is conducted on the vehicle to be tested on a preset straight road. The coasting speed of the vehicle under test load is obtained, and a theoretical deceleration reference curve for the vehicle when traveling on a straight road is generated based on the coasting speed.

6. The torque control method for switching from coasting to creeping according to claim 1, characterized in that, Based on the vehicle deceleration curve and the theoretical deceleration reference curve, the theoretical coasting curve of the vehicle is determined, specifically including: Based on the starting and ending speeds of the vehicle deceleration curve, the average deceleration of the vehicle during the preset time interval is determined. The theoretical load of the vehicle is determined based on the average deceleration and the vehicle's theoretical deceleration reference curve. Based on the vehicle's theoretical load, the vehicle's theoretical coasting curve is determined.

7. The torque control method for switching from coasting to creeping according to claim 1, characterized in that, Before generating a predicted slip curve based on the vehicle deceleration curve using a preset slip curve prediction algorithm, the method further includes: Obtain deceleration curves of sample vehicles with different loads under different working conditions and road conditions, where the vehicle coasting speed is lower than a preset threshold and within a preset time interval, and obtain complete sample vehicle deceleration curves corresponding to the several different load vehicles. Based on the deceleration curves of the sample vehicles and the deceleration curves of the complete sample vehicles, a preset coasting curve prediction algorithm is trained until the training converges.

8. A torque control device for switching from coasting to creeping, characterized in that, The device includes: a construction module, an acquisition module, a generation module, a determination module, and a calculation module; The construction module is used to construct a theoretical deceleration reference curve for a vehicle traveling on a straight road based on a preset vehicle load gradient. The acquisition module is used to acquire the vehicle deceleration curve over a preset time interval when the vehicle coasting speed is lower than a preset threshold, and to determine the theoretical coasting curve of the vehicle based on the vehicle deceleration curve and the theoretical deceleration reference curve. The generation module is used to generate a predicted slip curve based on the vehicle deceleration curve using a preset slip curve prediction algorithm. The determining module is used to determine the theoretical gliding deceleration based on the theoretical gliding curve, and to determine the predicted gliding deceleration based on the predicted gliding curve. The calculation module is used to calculate the creep preset torque under the current working condition based on the theoretical coasting deceleration and the predicted coasting deceleration.

9. A torque control device for switching from coasting to creeping, characterized in that, The device includes: At least one processor; And, a memory communicatively connected to the at least one processor; The memory stores instructions executable by the at least one processor, which, when executed by the at least one processor, enable the at least one processor to: Based on the preset vehicle load gradient, a theoretical deceleration reference curve is constructed for the vehicle when it is traveling on a straight road. When the vehicle's coasting speed is lower than a preset threshold, the vehicle deceleration curve at a preset time interval is obtained, and the theoretical coasting curve of the vehicle is determined based on the vehicle deceleration curve and the theoretical deceleration reference curve. Based on the vehicle deceleration curve, a predicted slip curve is generated using a preset slip curve prediction algorithm; Based on the theoretical gliding curve, the theoretical gliding deceleration is determined, and based on the predicted gliding curve, the predicted gliding deceleration is determined. The creep preset torque under the current operating condition is calculated based on the theoretical and predicted gliding deceleration.

10. A non-volatile computer storage medium for torque control of coasting to creep switching, storing computer-executable instructions, characterized in that, The computer-executable instructions are set as follows: Based on the preset vehicle load gradient, a theoretical deceleration reference curve is constructed for the vehicle when it is traveling on a straight road. When the vehicle's coasting speed is lower than a preset threshold, the vehicle deceleration curve at a preset time interval is obtained, and the theoretical coasting curve of the vehicle is determined based on the vehicle deceleration curve and the theoretical deceleration reference curve. Based on the vehicle deceleration curve, a predicted slip curve is generated using a preset slip curve prediction algorithm; Based on the theoretical gliding curve, the theoretical gliding deceleration is determined, and based on the predicted gliding curve, the predicted gliding deceleration is determined. The creep preset torque under the current operating condition is calculated based on the theoretical and predicted gliding deceleration.

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