Control method for work machine, work machine, control device, and storage medium

Abstract

The application discloses a control method of a working machine, the working machine, a control device and a storage medium, wherein the working machine comprises a hydraulic pump, a hydraulic motor and an engine. The control method comprises the following steps: acquiring a current speed gear of the engine; adjusting the flow of the hydraulic pump according to the current speed gear, so as to perform constant flow control on the hydraulic pump; acquiring a given displacement of the hydraulic motor under the condition of performing the constant flow control on the hydraulic pump; determining a motor current value corresponding to the hydraulic motor according to a preset displacement and the given displacement, wherein the preset displacement is determined based on the current speed gear; and adjusting a current corresponding to the hydraulic motor according to the motor current value, so as to control the working machine. The application can improve the starting speed of the working machine.

Description

Technical Field

[0001] This application relates to the field of work machinery technology, specifically to a control method for work machinery, work machinery, control device, and storage medium. Background Technology

[0002] When starting construction machinery (such as excavators) in mountainous terrain, initial starting difficulties arise due to factors such as air density, temperature, hydraulic viscosity, and pre-set horsepower conditions. Because of these environmental influences, the engine can burn less oxygen per unit time under the same torque load compared to flat ground, leading to a decrease in engine speed per minute and consequently, slower starting speeds in these challenging environments. Summary of the Invention

[0003] The purpose of this application is to provide a control method, a machine, a control device, and a storage medium for operating machinery, in order to solve the problem of slow start-up speed of operating machinery in the prior art.

[0004] To achieve the above objectives, the first aspect of this application provides a control method for a work machine, the work machine including a hydraulic pump, a hydraulic motor, and an engine, the control method comprising:

[0005] Get the engine's current speed and gear;

[0006] Adjust the flow rate of the hydraulic pump according to the current speed setting to achieve constant flow control of the hydraulic pump;

[0007] Under constant flow control of the hydraulic pump, the given displacement of the hydraulic motor is obtained;

[0008] Based on the preset displacement and the given displacement, determine the corresponding motor current value of the hydraulic motor; the preset displacement is determined based on the current speed gear; and

[0009] Adjust the current of the hydraulic motor according to the motor current value to control the working machinery.

[0010] In this embodiment of the application, adjusting the flow rate of the hydraulic pump according to the current speed gear includes:

[0011] Based on the current speed gear, determine the first current value and the second current value corresponding to the hydraulic pump. The first current value is related to the engine torque, and the second current value is related to the engine's actual load rate.

[0012] The smaller of the first and second current values ​​is determined as the main pump current value corresponding to the hydraulic pump.

[0013] Adjust the flow rate of the hydraulic pump according to the main pump current value.

[0014] In this embodiment of the application, determining the first current value corresponding to the hydraulic pump based on the current speed gear includes:

[0015] Determine the engine speed corresponding to the current speed gear;

[0016] Determine the engine torque corresponding to the engine speed;

[0017] The current value corresponding to the engine torque is determined as the first current value.

[0018] In this embodiment of the application, determining the second current value corresponding to the hydraulic pump based on the current speed gear includes:

[0019] The engine power corresponding to the current speed gear is calculated using a preset PID control algorithm to obtain the actual load rate of the engine.

[0020] The current value corresponding to the actual load rate is determined as the second current value.

[0021] In this embodiment of the application, determining the motor current value corresponding to the hydraulic motor based on the preset displacement and the given displacement includes:

[0022] The smaller of the preset displacement and the given displacement is determined as the target displacement of the hydraulic motor;

[0023] The current value corresponding to the target displacement is determined as the motor current value corresponding to the hydraulic motor.

[0024] In this embodiment of the application, the preset displacement is obtained through the following steps:

[0025] The first average speed of the operating machinery in the first operating state and the second average speed of the operating machinery in the second operating state are obtained.

[0026] The first displacement of the hydraulic motor is determined based on the first average vehicle speed, and the second displacement of the hydraulic motor is determined based on the second average vehicle speed.

[0027] The smaller displacement between the first and second displacements is determined as the preset displacement.

[0028] The first operating state indicates that the working machine is operating in the first speed range of the current speed gear, and the second operating state indicates that the working machine is operating in the second speed range of the current speed gear. The minimum speed included in the first speed range is greater than the maximum speed included in the second speed range.

[0029] In this embodiment of the application, obtaining the given displacement of the hydraulic motor includes:

[0030] Obtain the initial position and target position of the pedals of the operating machinery;

[0031] Determine the pedal travel corresponding to the pedal based on the initial position and the target position;

[0032] The given displacement is determined based on the pedal travel.

[0033] A second aspect of this application provides a control device for a work machine, wherein the work machine includes a hydraulic pump, a hydraulic motor, and an engine, and the control device includes:

[0034] The first solenoid valve is configured to regulate the displacement of the hydraulic motor;

[0035] The second solenoid valve is configured to regulate the flow rate of the hydraulic pump;

[0036] The controller is configured to control the aforementioned operating machinery.

[0037] A third aspect of this application provides a work machine, comprising:

[0038] engine;

[0039] Hydraulic pump;

[0040] Hydraulic motors; and

[0041] The control device for the aforementioned operating machinery.

[0042] A fourth aspect of this application provides a machine-readable storage medium storing instructions for causing a machine to perform the aforementioned control method for the working machinery.

[0043] The above technical solution first implements constant flow control for the hydraulic pump. When the hydraulic pump maintains a constant flow output, the smaller of the given displacement and the preset displacement of the hydraulic motor is determined as the target displacement. Based on the target displacement, a second target current value for the hydraulic motor is further determined. Using the second target current value as a reference, the corresponding current of the hydraulic motor can be adjusted to make it operate stably near the second target current value, thereby maintaining the displacement of the hydraulic motor at the target displacement. This target displacement can be the smallest acceptable displacement while ensuring the normal operation of the working machinery. With a constant output flow of the hydraulic pump, the smaller the displacement of the hydraulic motor, the higher its speed, which can improve the starting speed of the working machinery.

[0044] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0045] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings:

[0046] Figure 1 A flowchart illustrating a control method for a work machine according to an embodiment of this application is shown schematically.

[0047] Figure 2 This schematic diagram illustrates the structural block diagram of a control device for a work machine according to an embodiment of this application;

[0048] Figure 3a and Figure 3b The diagram illustrates the relationship between the hydraulic pump current and the travel motor speed according to an embodiment of this application. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of this application and are not intended to limit the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0050] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0051] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0052] In the embodiments of this application, the hydraulic motor, the hydraulic travel motor, and the travel motor can be used interchangeably.

[0053] Figure 1A flowchart illustrating a control method for a work machine according to an embodiment of this application is shown schematically. Figure 1 As shown in the figure, this application provides a control method for a work machine, which may include a hydraulic pump, a hydraulic motor, and an engine. The method may include the following steps.

[0054] Step 101: Obtain the current speed gear of the engine.

[0055] Specifically, in this embodiment, the engine can be configured with multiple speed gears, each corresponding to a preset engine speed. For example, when the driver sets the engine to the current gear by operating the gear shift mechanism, the gear information can be read to obtain the current speed gear. In this embodiment, an example of the working machinery can be an excavator. The excavator's walking system can be a hydraulic closed-loop walking system or a walking system.

[0056] Step 102: Adjust the flow rate of the hydraulic pump according to the current speed setting to achieve constant flow control of the hydraulic pump.

[0057] In one embodiment of this application, a PID control algorithm, for example, can be used to control the hydraulic pump at a constant flow rate. For instance, a flow rate setpoint can be determined based on actual needs, and this setpoint is input to the PID control algorithm (controller). The current of the hydraulic pump is adjusted according to the setpoint to regulate the output flow rate of the hydraulic pump. In one example, the current of the hydraulic pump may include the input current of the hydraulic pump; in this case, the magnitude of the input current can be adjusted to regulate the output flow rate of the hydraulic pump. In another example, the output flow rate of the hydraulic pump can be adjusted by regulating the opening of a solenoid valve (e.g., a proportional solenoid valve). In this example, the current of the hydraulic pump may include the input current of the solenoid valve; adjusting the input current of the solenoid valve adjusts its opening, thereby regulating the output flow rate of the hydraulic pump.

[0058] In a preferred embodiment of this application, adjusting the flow rate of the hydraulic pump according to the current speed setting may include:

[0059] Based on the current speed gear, determine the corresponding first current value and second current value of the hydraulic pump; the first current value is related to the engine torque, and the second current value is related to the engine's actual load rate.

[0060] The smaller of the first and second current values ​​is determined as the main pump current value corresponding to the hydraulic pump.

[0061] Adjust the flow rate of the hydraulic pump according to the main pump current value.

[0062] In this embodiment of the application, determining the first current value corresponding to the hydraulic pump based on the current speed gear includes:

[0063] Determine the engine speed corresponding to the current speed gear;

[0064] Determine the engine torque corresponding to the engine speed;

[0065] The current value corresponding to the engine torque is determined as the first current value.

[0066] Specifically, the correspondence or functional expression between speed gear and engine speed can be pre-set. After obtaining the current speed gear, the engine speed corresponding to the current speed gear can be obtained according to this correspondence or functional expression. Similarly, the relationship or functional expression between engine speed and engine torque can also be pre-set, and the engine torque corresponding to the engine speed can be obtained according to this relationship or functional expression. Likewise, the correspondence or functional expression between engine torque and hydraulic pump current can also be pre-set, and the first current value of the hydraulic pump corresponding to the engine torque can be obtained according to this correspondence or functional expression.

[0067] In this embodiment of the application, determining the second current value corresponding to the hydraulic pump based on the current speed gear includes:

[0068] The engine power corresponding to the current speed gear is calculated using a preset PID control algorithm to obtain the actual load rate of the engine.

[0069] The current value corresponding to the actual load rate is determined as the second current value.

[0070] Specifically, since the engine power is constant, it equals the engine speed multiplied by the engine torque. Each speed gear corresponds to a specific engine power, which can be used to match the hydraulic pump power. Inputting the hydraulic pump power into a preset PID control algorithm yields the actual load rate of the hydraulic pump. The correspondence or functional expression between the actual load rate of the hydraulic pump and its second current value can be predetermined. After determining the actual load rate using the aforementioned technical solution, the second current value corresponding to the current actual load rate can be obtained based on this correspondence or functional expression. Once the second current value is determined, the smaller of the first and second current values ​​can be identified as the main pump current value corresponding to the hydraulic pump. The flow rate of the hydraulic pump (i.e., the output flow rate) is adjusted according to the corresponding main pump current value, thereby achieving constant flow control of the hydraulic pump's output flow rate.

[0071] By determining the main pump current value using the above method, the target flow rate corresponding to the main pump current value can be determined. The hydraulic pump can then be controlled with constant flow to stabilize its output flow rate at the target flow rate. This ensures that the hydraulic pump operates normally and has a stable output flow rate, which is more conducive to adjusting the displacement of the hydraulic motor to improve the starting speed of the working machinery.

[0072] Step 103: Under constant flow control of the hydraulic pump, obtain the given displacement of the hydraulic motor.

[0073] In this embodiment of the application, obtaining the given displacement of the hydraulic motor includes: obtaining the initial position and the target position corresponding to the pedal of the working machine; determining the pedal stroke corresponding to the pedal based on the initial position and the target position; and determining the given displacement based on the pedal stroke.

[0074] When the operator depresses the accelerator pedal of the working machinery, the position of the accelerator pedal after it is depressed (or the change in position relative to the initial position (or accelerator pedal travel)) corresponds to the set displacement (given displacement) of the hydraulic motor. The given displacement of the hydraulic motor can be obtained by reading the position or travel of the accelerator pedal. Those skilled in the art will understand that although the accelerator pedal is used as an example, it is applicable to other types of accelerators or acceleration devices as well.

[0075] Step 104: Determine the motor current value corresponding to the hydraulic motor based on the preset displacement and the given displacement. The preset displacement is determined based on the current speed gear; and

[0076] Step 105: Adjust the current of the hydraulic motor according to the motor current value to control the working machinery.

[0077] In this embodiment, the preset displacement can be a fixed quantity, and the given displacement can be a variable. Each speed gear can correspond to a preset displacement, and the corresponding preset displacement can be determined based on the current speed gear. When the hydraulic pump outputs a constant flow to the hydraulic motor, and the given displacement is lower than the preset displacement, it is known that the speed corresponding to the given displacement will be higher than the speed corresponding to the preset displacement, based on the principle that flow rate equals the product of speed and displacement. Similarly, when the given displacement is higher than the preset displacement, the speed corresponding to the given displacement will be lower than the speed corresponding to the preset displacement. The correspondence or functional expression between displacement and current can be preset. The smaller of the given displacement and the preset displacement is determined as the target displacement, and the target current value corresponding to the target displacement can be determined based on the target displacement. It should be noted that the target current value is the current value input to the hydraulic motor under ideal conditions. By controlling the current actual current value of the hydraulic motor to be as close as possible to the target current value (or stabilized at the target current value), it can be ensured that the speed corresponding to the actual displacement of the hydraulic motor is the highest speed that the hydraulic motor can achieve under the current constant flow input to the hydraulic motor, thereby realizing the accelerated start-up of the working machinery.

[0078] The above technical solution adjusts the hydraulic pump's output flow rate according to the engine's current speed gear, thereby achieving constant flow control of the hydraulic pump's output flow rate. While maintaining constant flow control of the hydraulic pump, the given displacement of the hydraulic motor is obtained, and the smaller of the given displacement and the preset displacement is determined as the target displacement. The target current value corresponding to the target displacement is used as the ideal current value input to the hydraulic motor. With a constant flow rate delivered from the hydraulic pump to the hydraulic motor, based on the principle that flow rate equals the product of speed and displacement (i.e., speed and displacement are inversely proportional), the actual current of the hydraulic motor is adjusted to approach (or stabilize at) the target current value, thus adjusting the actual displacement of the hydraulic motor. This, in turn, adjusts the hydraulic motor's speed to the maximum speed achievable under the aforementioned conditions, thereby improving the starting speed of the working machinery.

[0079] In this embodiment of the application, determining the motor current value corresponding to the hydraulic motor based on the preset displacement and the given displacement includes: determining the smaller displacement between the preset displacement and the given displacement as the target displacement corresponding to the hydraulic motor; and determining the current value corresponding to the target displacement as the motor current value corresponding to the hydraulic motor.

[0080] In this embodiment, the preset displacement can be obtained through the following steps: obtaining the first average speed of the working machinery in a first operating state and the second average speed of the working machinery in a second operating state; determining the first displacement corresponding to the hydraulic motor based on the first average speed and the second displacement corresponding to the hydraulic motor based on the second average speed; determining the smaller displacement between the first displacement and the second displacement as the preset displacement; wherein, the first operating state represents the working machinery operating in a first speed range within the current speed gear, and the second operating state represents the working machinery operating in a second speed range within the current speed gear, wherein the minimum speed included in the first speed range is greater than the maximum speed included in the second speed range.

[0081] In this embodiment, the first operating state can be a high-speed walking state of the working machinery, and the second operating state can be a low-speed walking state of the working machinery. Each speed gear of the working machinery corresponds to a high-speed walking state and a low-speed walking state. During the walking process, the working machinery can switch speed states by selecting the corresponding walking state button or lever. High-speed walking state and low-speed walking state refer to the working machinery walking within a specific speed range. At this time, the working machinery is in a high-speed walking state or a low-speed walking state. If the working machinery is not in a high-speed walking state or a low-speed walking state, the working machinery is in a normal walking state. Preferably, the speed range of the high-speed walking state can be [15.2-15.9] km / h, and the speed range of the low-speed walking state can be [7.2-7.9] km / h. After determining the average speed in the high-speed walking state and the low-speed walking state respectively, the displacement corresponding to the current average speed can be determined by using a pre-determined relationship or function expression between speed and displacement.

[0082] The above technical solution adjusts the hydraulic pump's output flow rate according to the engine's current speed gear, thereby achieving constant flow control of the hydraulic pump's output flow rate. When the hydraulic pump maintains a constant flow output, the smaller of the hydraulic motor's given displacement and the preset optimal displacement is determined as the target displacement. The target current value corresponding to the target displacement is used as the ideal current value input to the hydraulic motor, thereby controlling the actual current value input to the hydraulic motor to maintain at the target current value. By comparing, for example, the given displacement corresponding to when the accelerator pedal is operated with the preset displacement determined by the above method, and taking the smaller one as the target displacement, the maximum allowable speed of the hydraulic motor can be determined, thereby improving the starting speed of the working machinery.

[0083] Figure 2 This schematically illustrates a structural block diagram of a control device for a work machine according to an embodiment of this application. Figure 2As shown in the illustration, this application provides a control device that can be applied to a work machine. The work machine may include a hydraulic pump, a hydraulic motor, and an engine. The control device may include:

[0084] The first solenoid valve 220 is configured to regulate the displacement of the hydraulic motor;

[0085] The second solenoid valve 230 is configured to regulate the flow rate of the hydraulic pump;

[0086] The controller 210 is configured to control the operating machinery as described above.

[0087] In this application embodiment, an example of the first solenoid valve 220 may include a solenoid proportional valve.

[0088] In this embodiment, the controller 210 can be configured to control the output flow rate of the hydraulic pump. In one example, the controller 210 can adjust the speed of the hydraulic pump by adjusting the current of the hydraulic pump, thereby controlling the output flow rate of the hydraulic pump. In another example, the controller 210 can adjust the opening degree of the solenoid valve by adjusting the current of a flow regulating element (e.g., a solenoid valve) disposed on the hydraulic pump, thereby controlling the output flow rate of the hydraulic pump. In this example, the control device may further include a second solenoid valve 230 configured to regulate the flow rate of the hydraulic pump. An example of the second solenoid valve 230 may include a solenoid proportional valve.

[0089] Specifically, in this embodiment of the application, the controller 210 can be configured to:

[0090] Get the engine's current speed and gear;

[0091] Adjust the flow rate of the hydraulic pump according to the current speed setting to achieve constant flow control of the hydraulic pump;

[0092] Under constant flow control of the hydraulic pump, the given displacement of the hydraulic motor is obtained;

[0093] Based on the preset displacement and the given displacement, determine the corresponding motor current value of the hydraulic motor; the preset displacement is determined based on the current speed gear; and

[0094] Adjust the current of the hydraulic motor according to the motor current value to control the working machinery.

[0095] This application also provides a working machine, which may include the engine, hydraulic pump and hydraulic motor described above, as well as the control device of the working machine described above.

[0096] Figure 3a and Figure 3b A schematic diagram illustrating the relationship between the hydraulic pump current and the travel motor speed according to an embodiment of this application is provided. Figure 3a and Figure 3b shown in the embodiments of the present application, Figure 3a and Figure 3b the ordinate on the left represents the flow rate of the hydraulic pump, the abscissa represents the pressure of the hydraulic pump, and the ordinate on the right represents the torque of the travel motor. It is assumed that the working machine requires the load rate of the hydraulic pump to be A at this time. The control current of the hydraulic pump when the load rate is A can be calculated through the preset relationship of the PID algorithm. This control current can be represented by I2, and the target current value of the hydraulic pump is represented by I1 or I3. If the target current value is less than the control current I2, that is, I1<I2, and the corresponding pressure P1>P2 at this time, then the constant power values corresponding to I1 and I2 are W respectively h1 >W h2 . When the travel motor is under constant torque, higher power corresponds to higher rotation speed. If the target current value is greater than the control current I2, that is, I3>I2, the corresponding pressure P2>P3 at this time. Under the condition of a constant flow rate, the power corresponding to the target current value (that is, W h3 ) is less than the load rate A of the hydraulic pump at this time (that is, W h2 ), that is, when the travel motor is at constant torque, the rotation speeds corresponding to power W h2 and W h3 are V2>V3. At this time, it is necessary to reduce the load rate A of the hydraulic pump so that I2≥I3, then the corresponding rotation speed V3 of the travel motor is greater than or equal to V2, and under this target current, the corresponding rotation speed also increases.

[0097] in Figure 3a , when the displacement of the travel motor remains unchanged, higher rotation speed of the travel motor corresponds to higher flow rate, which conforms to the fact that flow rate is equal to the product of rotation speed and displacement, that is, rotation speed and displacement are in inverse proportion. The flow rate corresponding to rotation speed 1 is q h1 , the flow rate corresponding to rotation speed 2 is q h2 , and the flow rate corresponding to rotation speed 3 is q h3 . Rotation speed 1, rotation speed 2 and rotation speed 3 also respectively correspond to power W h1 , W h2 and W h3 . Since the product of rotation speed and torque is equal to power, the curve representing rotation speed can also represent power. Under constant power, the higher the pressure, the smaller the flow rate, and the lower the corresponding rotation speed of the travel motor; the lower the pressure, the larger the flow rate, and the higher the corresponding rotation speed of the travel motor. In Figure 3b , currents I1, I2 and I3 respectively represent three hydraulic pump currents of different magnitudes, and smaller current corresponds to higher hydraulic pump pressure.

[0098] This application also provides a machine-readable storage medium storing instructions for causing a machine to perform the aforementioned control method for the working machinery.

[0099] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied 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.

[0100] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. 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, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0101] 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.

[0102] 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.

[0103] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0104] Memory may include non-persistent memory 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.

[0105] 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 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.

[0106] 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 process, method, article, or apparatus. Unless otherwise specified, 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 that element.

[0107] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A control method for a working machine, the working machine comprising a hydraulic pump, a hydraulic motor, and an engine, characterized in that, The control method includes: Obtain the current speed and gear of the engine; Adjust the flow rate of the hydraulic pump according to the current speed gear to achieve constant flow control of the hydraulic pump; Under constant flow control of the hydraulic pump, the given displacement of the hydraulic motor is obtained; The smaller of the preset displacement and the given displacement is determined as the target displacement corresponding to the hydraulic motor; The current value corresponding to the target displacement is determined as the motor current value corresponding to the hydraulic motor; Adjust the current of the hydraulic motor according to the motor current value to control the working machinery; The preset displacement is obtained through the following steps: The first average speed of the operating machinery in a first operating state and the second average speed of the operating machinery in a second operating state are obtained. The first displacement of the hydraulic motor is determined based on the first average vehicle speed, and the second displacement of the hydraulic motor is determined based on the second average vehicle speed. The smaller displacement between the first displacement and the second displacement is determined as the preset displacement; The first operating state indicates that the working machine is operating in a first speed range within the current speed gear, and the second operating state indicates that the working machine is operating in a second speed range within the current speed gear. The minimum speed included in the first speed range is greater than the maximum speed included in the second speed range.

2. The control method according to claim 1, characterized in that, Adjusting the flow rate of the hydraulic pump according to the current speed gear includes: Based on the current speed gear, determine the first current value and the second current value corresponding to the hydraulic pump; the first current value is related to the torque of the engine, and the second current value is related to the actual load rate of the engine; The smaller of the first current value and the second current value is determined as the main pump current value corresponding to the hydraulic pump; The flow rate of the hydraulic pump is adjusted according to the main pump current value.

3. The control method according to claim 2, characterized in that, Determining the first current value corresponding to the hydraulic pump based on the current speed gear includes: Determine the engine speed corresponding to the current speed gear; Determine the engine torque corresponding to the engine speed; The current value corresponding to the engine torque is determined as the first current value.

4. The control method according to claim 2, characterized in that, Determining the second current value corresponding to the hydraulic pump based on the current speed gear includes: The power of the engine corresponding to the current speed gear is calculated by using a preset PID control algorithm to obtain the actual load rate of the engine. The current value corresponding to the actual load rate is determined as the second current value.

5. The control method according to claim 1, characterized in that, Obtaining the given displacement of the hydraulic motor includes: Obtain the initial position and the target position corresponding to the pedal of the operating machinery; Based on the initial position and the target position, determine the pedal travel corresponding to the pedal; The given displacement is determined based on the pedal travel.

6. A control device for a work machine, characterized in that, The operating machinery includes a hydraulic pump, a hydraulic motor, and an engine; the control device includes: A first solenoid valve is configured to regulate the displacement of the hydraulic motor; The second solenoid valve is configured to regulate the flow rate of the hydraulic pump; A controller configured to perform the control method for the operating machinery according to any one of claims 1 to 5.

7. A type of operating machinery, characterized in that, include: engine; Hydraulic pump; Hydraulic motor; as well as The control device for the operating machinery according to claim 6.

8. A machine-readable storage medium, characterized in that, The machine-readable storage medium stores instructions for causing the machine to perform the control method for the working machinery according to any one of claims 1 to 5.

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