Electric tractor speed control method and device, medium, product and vehicle control unit

Abstract

The invention provides an electric tractor speed control method and device, a medium, a product and a vehicle control unit. The method comprises the steps that the target speed of the electric tractor is set; obtaining the current calculated vehicle speed of the electric tractor, and obtaining the current navigation vehicle speed of the electric tractor through navigation positioning equipment; executing speed control judgment operation based on the target vehicle speed, the current calculation vehicle speed and the current navigation vehicle speed to obtain a corresponding speed control judgment result; and under the condition that the obtained speed control judgment result is that speed control needs to be carried out, the motor rotating speed of the electric tractor is adjusted so that the electric tractor can run according to the target vehicle speed. Parts configured in the electric tractor are adopted for vehicle speed acquisition and control, the cost is low, and the precision of vehicle speed control of the electric tractor is improved.

Description

Technical Field

[0001] The present application relates to the field of new energy agricultural machinery technology, and in particular to a speed control method, device, medium, product and vehicle controller for an electric tractor. Background Art

[0002] With the application of new energy technologies in the field of agricultural machinery, the technical route of motor directly driving the gearbox and rear axle to move has been gradually applied and turned to actual vehicle verification. Due to its rapid response characteristics, the motor can quickly adjust the motor speed and power. Therefore, it is of great significance to explore the integration of the motor's rapid response performance and the speed control of the tractor vehicle.

[0003] With the improvement of the sophistication of agricultural machinery (such as precision seeders and precision fertilizer applicators), the level of operation quality (such as sowing row spacing) is strongly related to the accuracy requirements of the travel speed of the tractor-driven machinery, so how to achieve precise control of the tractor's travel speed is the key.

[0004] When a tractor is operating in the field, its wheels may slip to varying degrees due to varying factors such as soil conditions (such as softness and muddiness), tire inflation pressure (unstable tire radius), and operating loads (such as large differences in plowing and sowing loads). Since existing vehicle speed displays are calculated based on the relationship between tire speed and tire radius, when the tires slip, the difference between the tractor's actual running speed and the speed converted from the tire speed is large (when the wheels slip severely, the slip rate can be 30-50% or even higher). This distortion in vehicle speed acquisition directly affects the tractor's precise operating objectives. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of this application is to provide an electric tractor speed control method, device, medium, product and vehicle controller to solve the problem of low speed control accuracy of the above-mentioned existing electric tractors.

[0006] To achieve the above-mentioned purpose and other related purposes, the first aspect of the present application provides an electric tractor speed control method, which is applied to an electric tractor and executed by a vehicle controller of the electric tractor, comprising: obtaining a target speed of the electric tractor; obtaining a current calculated speed of the electric tractor, and obtaining the current navigation speed of the electric tractor through a navigation and positioning device of the electric tractor; performing a speed control judgment operation based on the target speed, the current calculated speed and the current navigation speed to obtain a corresponding speed control judgment result; wherein the speed control judgment operation includes: one or more of a navigation speed judgment operation, a speed difference judgment operation and a slip rate judgment operation; when a speed control judgment result requiring speed control is obtained, adjusting the motor speed of the electric tractor so that the electric tractor travels at the target speed.

[0007] In some embodiments of the first aspect of the present application, the method for obtaining the current calculated vehicle speed of the electric tractor specifically includes: collecting the current motor speed or the current rear axle gear speed of the electric tractor; based on the current motor speed or the current rear axle gear speed, according to the vehicle speed calculation formula, obtaining the current calculated vehicle speed of the electric tractor.

[0008] In some embodiments of the first aspect of the present application, the navigation vehicle speed judgment operation includes: comparing the current navigation vehicle speed with a pre-set first vehicle speed judgment threshold; if the current navigation vehicle speed is greater than the first vehicle speed judgment threshold, obtaining a speed control judgment result that does not require speed control; if the current navigation vehicle speed is not greater than the first vehicle speed judgment threshold, performing a speed difference judgment operation.

[0009] In some embodiments of the first aspect of the present application, the speed difference judgment operation includes: calculating the speed difference between the target vehicle speed and the current navigation vehicle speed; if the absolute value of the speed difference is less than a preset second vehicle speed judgment threshold, obtaining a speed control judgment result that no speed control is required; if the absolute value of the speed difference is not less than the preset second vehicle speed judgment threshold, performing a slip rate judgment operation.

[0010] In some embodiments of the first aspect of the present application, the slip rate determination operation includes: calculating a current slip rate based on the target vehicle speed and the current calculated vehicle speed according to a slip rate calculation formula; if the current slip rate is greater than a set slip rate threshold, obtaining a speed control determination result that no speed control is required; if the current slip rate is not greater than the set slip rate threshold, obtaining a speed control determination result that speed control is required.

[0011] In some embodiments of the first aspect of the present application, adjusting the motor speed of the electric tractor so that the electric tractor travels at the target speed includes: adjusting the motor speed of the electric tractor at least once according to a speed calculation formula until the absolute value of the speed difference between the current navigation speed of the electric tractor and the target speed is less than the second speed judgment threshold.

[0012] To achieve the above-mentioned purpose and other related purposes, the second aspect of the present application provides an electric tractor speed control device, which is arranged in the vehicle controller of the electric tractor, including: an acquisition module, used to obtain the target speed of the electric tractor; also used to obtain the current calculated speed of the electric tractor, and obtain the current navigation speed of the electric tractor through the navigation and positioning equipment of the electric tractor; a judgment module, used to perform a speed control judgment operation based on the target speed, the current calculated speed and the current actual speed, and obtain a corresponding speed control judgment result; wherein the speed control judgment operation includes: one or more of a navigation speed judgment operation, a speed difference judgment operation and a slip rate judgment operation; a speed adjustment module, used to adjust the motor speed of the electric tractor when a speed control judgment result requiring speed control is obtained, so that the electric tractor travels according to the target speed.

[0013] To achieve the above-mentioned purpose and other related purposes, the third aspect of the present application provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the electric tractor speed control method is implemented.

[0014] To achieve the above-mentioned objectives and other related objectives, the fourth aspect of the present application provides a computer program product, which includes computer program code. When the computer program code is run on a computer, the computer implements the electric tractor speed control method.

[0015] To achieve the above-mentioned purpose and other related purposes, the fifth aspect of the present application provides a vehicle controller, including a memory, a processor and a computer program stored in the memory; the processor executes the computer program to implement the electric tractor speed control method.

[0016] As described above, the electric tractor speed control method, device, medium, product, and vehicle controller of the present application have the following beneficial effects:

[0017] This application uses components already configured on the electric tractor to acquire and control the vehicle speed, which is low-cost and improves the accuracy of the electric tractor's speed control. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Shown is a schematic structural diagram of an electric tractor in the prior art.

[0019] Figure 2 Shown is a flow chart of a method for controlling the speed of an electric tractor according to an embodiment of the present application.

[0020] Figure 3Shown is a specific flow chart of the electric tractor speed control method in one embodiment of the present application.

[0021] Figure 4 Shown is a schematic block diagram of an electric tractor speed control device according to an embodiment of the present application.

[0022] Figure 5 Shown is a structural diagram of a vehicle controller in one embodiment of the present application. DETAILED DESCRIPTION

[0023] The following describes the embodiments of the present application through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other unless they conflict.

[0024] In the embodiments of this application, terms such as "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that terms such as "first" and "second" do not limit the quantity or order of execution, and that terms such as "first" and "second" do not necessarily define differences.

[0025] It should be noted that in the embodiments of this application, words such as "exemplary" or "for example" represent examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0026] In the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can represent: a, b, c, ab, ac, bc or abc, where a, b, c can be single or multiple.

[0027] Before further describing the present invention in detail, the structure of the electric tractor according to the embodiment of the present invention is explained:

[0028] Electric tractors such as Figure 1 As shown, the system primarily includes: a drive motor, a gearbox, a rear axle box, a speed sensor, a navigation and positioning receiver, and an assisted driving actuator. The drive motor is located in front of the gearbox. The rear axle box is located behind the gearbox and connects to the tractor's rear drive wheels. The order "front" and "back" indicates the direction of power transmission. The speed sensor is typically located at the rear axle box. The navigation and positioning receiver is typically located on top of the tractor. The assisted driving actuator is the steering wheel.

[0029] To facilitate understanding of the embodiments of this application, first Figure 2 Detailed description. Figure 2 The following is a flow chart showing a method for controlling the speed of an electric tractor according to an embodiment of the present invention. The method is executed by the vehicle controller of the electric tractor. The method primarily includes the following steps:

[0030] Step S21: obtaining the target speed of the electric tractor; obtaining the current calculated speed of the electric tractor, and obtaining the current navigation speed of the electric tractor through the navigation and positioning device of the electric tractor.

[0031] It should be understood that the target speed can be set according to the working condition of the tractor. The electric tractor speed control method in this embodiment is mainly aimed at the scene of tractor working in the field. Road transportation does not require the navigation and positioning equipment to be turned on, so there is no navigation speed information.

[0032] In one embodiment, the method for obtaining the current calculated vehicle speed of the electric tractor specifically includes: collecting the current motor speed or the current rear axle gear speed of the electric tractor; and obtaining the current calculated vehicle speed of the electric tractor based on the current motor speed or the current rear axle gear speed according to a vehicle speed calculation formula.

[0033] It should be understood that a speed sensor can be installed on the output shaft of the electric tractor's drive motor to measure the speed of the drive motor. The speed of the electric tractor's drive motor is the motor speed. A speed sensor can also be installed on any gear stage in the rear axle box to measure the speed of that gear. The speed of the gear on which the speed sensor is installed is the rear axle gear speed.

[0034] In one embodiment, the navigation and positioning device may use Beidou navigation.

[0035] Step S22: Based on the target vehicle speed, the current calculated vehicle speed, and the current actual vehicle speed, a speed control judgment operation is performed to obtain a corresponding speed control judgment result; wherein the speed control judgment operation includes: one or more of a navigation vehicle speed judgment operation, a speed difference judgment operation, and a slip rate judgment operation.

[0036] In one embodiment, the navigation vehicle speed determination operation includes: comparing the current navigation vehicle speed with a pre-set first vehicle speed determination threshold; if the current navigation vehicle speed is greater than the first vehicle speed determination threshold, obtaining a speed control determination result that no speed control is required; if the current navigation vehicle speed is not greater than the first vehicle speed determination threshold, performing a speed difference determination operation.

[0037] In one embodiment, the speed difference determination operation includes: calculating the speed difference between the target vehicle speed and the current navigation vehicle speed; if the absolute value of the speed difference is less than a preset second vehicle speed determination threshold, obtaining a speed control determination result that no speed control is required; if the absolute value of the speed difference is not less than the preset second vehicle speed determination threshold, performing a slip rate determination operation.

[0038] In one embodiment, the slip ratio determination operation includes: calculating the current slip ratio based on the target vehicle speed and the current calculated vehicle speed according to a slip ratio calculation formula; determining that speed control is not required if the current slip ratio is greater than a set slip ratio threshold; and determining that speed control is required if the current slip ratio is not greater than the set slip ratio threshold. It should be understood that the slip ratio is the ratio of the actual wheel speed to the theoretical pure rolling speed.

[0039] Step S23: When a speed control judgment result indicating that speed control is required is obtained, the motor speed of the electric tractor is adjusted so that the electric tractor travels at the target speed.

[0040] In one embodiment, adjusting the motor speed of the electric tractor so that the electric tractor travels at the target speed includes: adjusting the motor speed of the electric tractor at least once according to a speed calculation formula until the absolute value of the speed difference between the current calculated speed of the electric tractor and the target speed is less than the second speed judgment threshold.

[0041] The following will be combined with the attached Figure 3 The process of vehicle speed control is described in detail:

[0042] Get the target speed V of the electric tractor mMoreover, collect the rotational speed of the drive motor of the electric tractor or the rotational speed of any stage of gears in the rear axle housing. Obtain the tire dynamic radius r of the electric tractor. Calculate the current calculated vehicle speed V0 of the electric tractor according to the vehicle speed calculation formula described in Formula 1 below:

[0043] V0 = 3.6×2πrn0 / (i×60); (Formula 1)

[0044] Where, n0 is the rotational speed of the drive motor collected or the rotational speed of any stage of gears in the rear axle housing. If n0 is the rotational speed of the drive motor collected, then i is the transmission ratio from the drive motor to the wheels; if n0 is the rotational speed of any stage of gears in the rear axle housing, then i is the transmission ratio from the speed sensor to the tires.

[0045] Meanwhile, obtain the current navigation speed V1 of the electric tractor through the navigation and positioning device.

[0046] It should be noted that during the acceleration start, due to the large load of the electric tractor, the driving wheels will slip, the current calculated vehicle speed V0 is greater than the actual vehicle speed, and the current navigation speed V1 obtained by the navigation and positioning device is close to the actual vehicle speed of the electric tractor (the error is generally between 0.1 and 0.3 km / h).

[0047] Furthermore, the vehicle controller obtains the current calculated vehicle speed V0 and the current navigation speed V1. Then, compare the current navigation speed V1 of the electric tractor with the previously obtained first vehicle speed judgment threshold a. Generally, set the first vehicle speed judgment threshold a to be equal to 15 km / h. If V1 > a, it is judged that no speed control is required for the electric tractor; if V1 ≤ a, calculate the absolute value V2 of the speed difference between the current navigation speed V1 of the electric tractor and the target vehicle speed V m It should be noted that V1 ≤ 15 km / h is the vehicle speed for the field operation condition of the electric tractor.

[0048] Then, compare the absolute value V2 of the speed difference with the previously obtained second vehicle speed judgment threshold b. Generally, set the second vehicle speed judgment threshold b to be 0.5 km / h. If V2 < b, it is judged that no speed control is required for the electric tractor; if V2 ≥ b, based on the target vehicle speed V m and the current calculated vehicle speed V0, and calculate the current slip ratio δ according to the following Formula 2:

[0049] <0,

[0050] Compare the slip ratio δ with the set slip ratio threshold. If δ > 40%, it is judged that no speed control is required for the electric tractor; if

[0051] If δ ≤ 40%, the electric tractor needs to increase its rotational speed to increase its speed. It should be understood that the slip ratio is the ratio of the actual wheel speed to the theoretical pure rolling speed. The slip ratio threshold can also be set to other values ​​as needed, and this is not limited in the present invention.

[0052] Furthermore, based on the current navigation vehicle speed V1 and the target vehicle speed V m , calculate the target adjustment speed n′ of the motor according to the following formula 3:

[0053] n′=i1×(V m -V1)×i0×60 / (3.6×2πr); (Formula 3);

[0054] Among them, i0 is the speed ratio from the speed sensor to the wheel end, and i1 is the speed ratio from the drive motor to the speed sensor.

[0055] Furthermore, the navigation vehicle speed is collected again through the navigation positioning device. If the absolute value of the speed difference between the newly collected navigation vehicle speed and the target vehicle speed is less than the second vehicle speed judgment threshold b, it means that the actual vehicle speed of the electric tractor has reached the target vehicle speed, and the motor speed adjustment is stopped; if the absolute value of the speed difference between the newly collected navigation vehicle speed and the target vehicle speed is not less than the second vehicle speed judgment threshold b, the motor speed is adjusted again according to Formula 3 until the speed difference between the navigation vehicle speed collected by the navigation device and the target vehicle speed is less than the second vehicle speed judgment threshold b.

[0056] In one embodiment, step 23 and step 24 are mainly performed by a VCU (vehicle controller unit).

[0057] It should be noted that the speed sensor, VCU, navigation and positioning equipment, etc. involved in the present invention are all existing parts of electric tractors. Compared with the existing technology that requires the additional installation of multiple detection equipment, the present invention has a simple structure and low cost. In addition, the present invention applies the slip rate to the vehicle speed control process. The present invention also adjusts the motor speed to provide feedback with the target vehicle speed, ultimately achieving the ideal vehicle speed within the target error range (the error is within 0.5km / h). The present invention can control the motor speed to achieve the expected value of the actual vehicle speed and the target vehicle speed, achieving the expected operating speed and operation quality.

[0058] Figure 4 FIG. 1 is a schematic block diagram of an electric tractor speed control device provided in an embodiment of the present application. Figure 4 As shown, the electric tractor speed control device includes:

[0059] A setting module 41 is used to obtain a target speed of the electric tractor;

[0060] An acquisition module 42 is configured to adjust the motor speed of the electric tractor when a speed control judgment result indicating that speed control is required is obtained, so that the electric tractor travels at the target speed;

[0061] a determination module 43 configured to perform a speed control determination operation based on the target vehicle speed, the current calculated vehicle speed, and the current actual vehicle speed to obtain a corresponding speed control determination result; wherein the speed control determination operation includes one or more of a navigation vehicle speed determination operation, a speed difference determination operation, and a slip ratio determination operation;

[0062] The speed adjustment module 44 is configured to adjust the motor speed of the electric tractor when the obtained speed control judgment result indicates that speed control is required, so that the electric tractor travels at the target speed.

[0063] It should be understood that the specific process of each module executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0064] It should also be understood that the division of modules in the embodiments of the present application is illustrative and is merely a logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the various embodiments of the present application may be integrated into a single processor, or may exist physically separately, or two or more modules may be integrated into a single module. The aforementioned integrated modules may be implemented in the form of hardware or software functional modules.

[0065] In some embodiments of the first aspect of the present application, the method for obtaining the current calculated vehicle speed of the electric tractor specifically includes: collecting the current motor speed or the current rear axle gear speed of the electric tractor; based on the current motor speed or the current rear axle gear speed, according to the vehicle speed calculation formula, obtaining the current calculated vehicle speed of the electric tractor.

[0066] In some embodiments of the first aspect of the present application, the navigation vehicle speed judgment operation includes: comparing the current navigation vehicle speed with a pre-set first vehicle speed judgment threshold; if the current navigation vehicle speed is greater than the first vehicle speed judgment threshold, obtaining a speed control judgment result that does not require speed control; if the current navigation vehicle speed is not greater than the first vehicle speed judgment threshold, performing a speed difference judgment operation.

[0067] In some embodiments of the first aspect of the present application, the speed difference judgment operation includes: calculating the speed difference between the target vehicle speed and the current navigation vehicle speed; if the absolute value of the speed difference is less than a preset second vehicle speed judgment threshold, obtaining a speed control judgment result that no speed control is required; if the absolute value of the speed difference is not less than the preset second vehicle speed judgment threshold, performing a slip rate judgment operation.

[0068] In some embodiments of the first aspect of the present application, the slip rate determination operation includes: calculating the current slip rate based on the target vehicle speed and the current calculated vehicle speed according to a slip rate calculation formula; if the current slip rate is greater than a set slip rate threshold, obtaining a speed control determination result that no speed control is required; if the current slip rate is not greater than the set slip rate threshold, obtaining a speed control determination result that speed control is required.

[0069] In some embodiments of the first aspect of the present application, adjusting the motor speed of the electric tractor so that the electric tractor travels at the target speed includes: adjusting the motor speed of the electric tractor at least once according to a speed calculation formula until the absolute value of the speed difference between the current navigation speed of the electric tractor and the target speed is less than the second speed judgment threshold.

[0070] Figure 5 This is a schematic block diagram of the vehicle controller provided in the embodiment of the present application. Figure 5 As shown, the vehicle controller includes: at least one processor 501, a memory 502, at least one network interface 503 and a user interface 505. The various components in the device are coupled together through a bus system 504. It is understood that the bus system 504 is used to achieve connection and communication between these components. In addition to the data bus, the bus system 504 also includes a power bus, a control bus and a status signal bus. However, for the sake of clarity, Figure 5 Various buses are labeled as bus systems.

[0071] The user interface 505 may include a display, a keyboard, a mouse, a trackball, a click gun, keys, buttons, a touch pad or a touch screen.

[0072] It will be appreciated that the memory 502 may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM) or a programmable read-only memory (PROM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM) and synchronous static random access memory (SSRAM). The memory described in the embodiments of the present invention is intended to include, but is not limited to, these and any other suitable types of memory.

[0073] The memory 502 in this embodiment of the present invention is used to store various types of data to support the operation of the vehicle controller 500. Examples of this data include: any executable program used to operate on the vehicle controller 500, such as the operating system 4021 and the application 5022; the operating system 5021 includes various system programs, such as the framework layer, core library layer, and driver layer, which are used to implement various basic services and process hardware-based tasks. The application 5022 can include various application programs, such as a media player (Media Player), a browser (Browser), etc., which are used to implement various application services. The electric tractor speed control method provided in this embodiment of the present invention can be included in the application 5022.

[0074] The methods disclosed in the above embodiments of the present invention can be applied to or implemented by processor 501. Processor 501 may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method can be completed by hardware integrated logic circuits in processor 501 or by software instructions. The above processor 501 may be a general-purpose processor, a digital signal processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. Processor 501 can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor 501 may be a microprocessor or any conventional processor. The steps of the accessory optimization method provided in conjunction with the embodiments of the present invention can be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium located in a memory. The processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above method.

[0075] In an exemplary embodiment, the vehicle controller 500 can be used by one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), and complex programmable logic devices (CPLDs) to execute the aforementioned method.

[0076] According to the method provided in the embodiment of the present application, the present application also provides a computer program product, which includes: a computer program code, which, when executed on a computer, causes the computer to execute Figure 2 The electric tractor speed control method in the illustrated embodiment.

[0077] According to the method provided in the embodiment of the present application, the present application also provides a computer-readable storage medium, which stores a program code, and when the program code is run on a computer, the computer executes Figure 2 The electric tractor speed control method in the illustrated embodiment.

[0078] As used in this specification, the terms "component," "module," "system," and the like are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. By way of illustration, both an application running on a computing device and a computing device can be a component. One or more components can reside in a process and / or an execution thread, and a component can be located on a computer and / or distributed between two or more computers. In addition, these components can be executed from various computer-readable media having various data structures stored thereon. Components can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component on a local system, a distributed system, and / or a network, such as the Internet interacting with other systems via signals).

[0079] Those skilled in the art will appreciate that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented using electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0080] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0081] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0082] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0083] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0084] In the above embodiments, the functions of each functional unit can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions (programs). When the computer program instructions (program) are loaded and executed on a computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. Available media may be magnetic media (e.g., floppy disks, hard disks, tapes), optical media (e.g., high-density digital video discs (DVDs), or semiconductor media (e.g., solid state disks (SSDs)).

[0085] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk, and other media that can store program codes.

[0086] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

[0087] In summary, the present application provides an electric tractor speed control method, device, medium, product and vehicle controller. The method includes: setting a target speed of the electric tractor; obtaining the current calculated speed of the electric tractor, and obtaining the current navigation speed of the electric tractor through a navigation and positioning device; performing a speed control judgment operation based on the target speed, the current calculated speed and the current navigation speed to obtain a corresponding speed control judgment result; when the speed control judgment result obtained is that speed control is required, adjusting the motor speed of the electric tractor so that the electric tractor travels at the target speed. The present application uses the components already configured in the electric tractor to obtain and control the speed, which is low in cost, and the present application improves the accuracy of the speed control of the electric tractor. Therefore, the present application effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0088] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical concepts disclosed in this application shall be covered by the claims of this application.

Claims

1. A method for controlling the speed of an electric tractor, characterized in that: Applied to an electric tractor and executed by the vehicle controller of the electric tractor, including: Obtaining a target speed of the electric tractor; obtaining a current calculated speed of the electric tractor, and obtaining a current navigation speed of the electric tractor through a navigation and positioning device of the electric tractor; Based on the target vehicle speed, the current calculated vehicle speed, and the current navigation vehicle speed, a speed control determination operation is performed to obtain a corresponding speed control determination result; wherein the speed control determination operation includes: one or more of a navigation vehicle speed determination operation, a speed difference determination operation, and a slip ratio determination operation; When a speed control judgment result indicating that speed control is required is obtained, the motor speed of the electric tractor is adjusted so that the electric tractor travels at the target speed.

2. The electric tractor speed control method according to claim 1, characterized in that: The method of obtaining the current calculated speed of the electric tractor specifically includes: The current motor speed or the current rear axle gear speed of the electric tractor is collected; based on the current motor speed or the current rear axle gear speed, according to a vehicle speed calculation formula, the current calculated vehicle speed of the electric tractor is obtained.

3. The electric tractor speed control method according to claim 2, characterized in that: Navigation vehicle speed judgment operations include: Comparing the current navigation vehicle speed with a preset first vehicle speed determination threshold; If the current navigation vehicle speed is greater than the first vehicle speed judgment threshold, obtaining a speed control judgment result indicating that no speed control is required; If the current navigation vehicle speed is not greater than the first vehicle speed judgment threshold, a speed difference judgment operation is performed.

4. The electric tractor speed control method according to claim 3, characterized in that: The speed difference judgment operation includes: Calculating a speed difference between the target vehicle speed and the current navigation vehicle speed; If the absolute value of the speed difference is less than a preset second vehicle speed judgment threshold, a speed control judgment result is obtained indicating that no speed control is required; If the absolute value of the speed difference is not less than a preset second vehicle speed determination threshold, a slip ratio determination operation is performed.

5. The electric tractor speed control method according to claim 4, characterized in that: The slip rate judgment operation includes: Calculating a current slip rate based on the target vehicle speed and the current calculated vehicle speed according to a slip rate calculation formula; If the current slip rate is greater than the set slip rate threshold, a speed control judgment result is obtained that no speed control is required; If the current slip rate is not greater than the set slip rate threshold, a speed control judgment result is obtained, indicating that speed control is required.

6. The electric tractor speed control method according to claim 5, characterized in that: Adjusting the motor speed of the electric tractor so that the electric tractor travels at the target speed includes: According to the speed calculation formula, the motor speed of the electric tractor is adjusted at least once until the absolute value of the speed difference between the current navigation speed of the electric tractor and the target speed is less than the second speed judgment threshold.

7. An electric tractor speed control device, characterized in that: The vehicle controller installed in the electric tractor includes: an acquisition module, configured to acquire a target speed of the electric tractor; and further configured to acquire a current calculated speed of the electric tractor, and acquire a current navigation speed of the electric tractor through a navigation and positioning device of the electric tractor; a determination module, configured to perform a speed control determination operation based on the target vehicle speed, the current calculated vehicle speed, and the current actual vehicle speed, and obtain a corresponding speed control determination result; wherein the speed control determination operation includes one or more of a navigation vehicle speed determination operation, a speed difference determination operation, and a slip ratio determination operation; The speed adjustment module is used to adjust the motor speed of the electric tractor when a speed control judgment result indicating that speed control is required is obtained, so that the electric tractor travels according to the target vehicle speed.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

9. A computer program product, characterized in that The computer program product includes computer program code, and when the computer program code is run on a computer, the computer is enabled to implement the method according to any one of claims 1 to 6.

10. A vehicle controller, comprising a memory, a processor, and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the method according to any one of claims 1 to 6.

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