Control method and device of work vehicle and work vehicle

Abstract

This invention provides a control method, device, and vehicle for a work vehicle, belonging to the field of mechanical control technology. The method includes: adjusting the vehicle's speed based on engine load rate; and, under predetermined conditions, adjusting the target engine speed based on the speed difference between the actual engine speed and the target engine speed. The control method, device, and vehicle provided by this invention, by monitoring the engine load rate in real time and performing segmented speed control, can effectively prevent unexpected events such as engine speed drop or stalling due to overload. It can rationally utilize engine efficiency, significantly improve work efficiency, reduce reliance on driver skills, and prevent damage to work equipment and transmission systems due to excessive changes in work load.

Description

Technical Field

[0001] This invention relates to the field of mechanical control technology, and in particular to a control method, device, and vehicle for a work vehicle. Background Technology

[0002] Currently, existing construction machinery, especially engineering machinery such as milling machines, does not have a linkage between its walking system and the engine's power system. Changes in walking speed (also known as travel speed) are generally not differentiated according to different engine load rates.

[0003] Meanwhile, when controlling the existing operating machinery, the load protection function was not considered. That is, when the load increases to the engine's operating limit, if the driver continues to push the driving handle to accelerate, the engine will accelerate in response to this operation, but will then slow down and shut down due to overload. This seriously affects the operating efficiency of the operating vehicle and may even cause damage to the operating equipment related to the operating vehicle, while also affecting the driver's driving comfort.

[0004] In view of this, it is urgent to improve the current control methods for work vehicles in order to improve their operational stability. Summary of the Invention

[0005] This invention provides a control method, device, and vehicle for work vehicles, which solves the defects of poor operational stability in existing technologies or improvements for work vehicles during operation. It can significantly improve work efficiency while making reasonable use of engine power, and at the same time reduce the dependence on driver skills.

[0006] In a first aspect, the present invention provides a control method for a work vehicle, comprising:

[0007] Adjust the driving speed of the work vehicle based on the engine load rate;

[0008] Under the premise that the preset conditions are met, the engine target speed is adjusted based on the speed difference between the actual engine speed and the engine target speed.

[0009] According to a control method for a work vehicle provided by the present invention, adjusting the travel speed of the work vehicle based on the engine load rate includes:

[0010] If the engine load rate is determined to be less than a first preset threshold, the driving speed of the work vehicle is increased by a first acceleration based on the speed increase signal.

[0011] According to a control method for a work vehicle provided by the present invention, the step of adjusting the travel speed of the work vehicle based on the engine load rate further includes:

[0012] If the engine load rate is determined to be greater than or equal to a first preset threshold but less than a second preset threshold, the driving speed of the work vehicle is increased by a second acceleration based on a speed increase signal; the second acceleration is less than the first acceleration.

[0013] According to a control method for a work vehicle provided by the present invention, the step of adjusting the travel speed of the work vehicle based on the engine load rate further includes:

[0014] If the engine load rate is determined to be equal to the second preset threshold, the speed increase signal is ignored and the driving speed of the work vehicle is maintained.

[0015] According to a control method for a work vehicle provided by the present invention, after maintaining the travel speed of the work vehicle, the method further includes:

[0016] If it is determined that the change in the workload of the work vehicle is greater than the load change threshold, the travel speed of the work vehicle is reduced by a third acceleration.

[0017] According to a control method for a work vehicle provided by the present invention, after reducing the travel speed of the work vehicle, the following operations are repeated according to a preset sampling period until the engine load rate is equal to a second preset threshold:

[0018] Reacquire the engine load rate;

[0019] If the new engine load rate is determined to be less than the third preset threshold, the driving speed of the work vehicle is increased by the fourth acceleration.

[0020] According to a control method for a work vehicle provided by the present invention, the step of adjusting the engine target speed based on the speed difference between the actual engine speed and the engine target speed under predetermined conditions includes:

[0021] If, under the preset condition that the engine load rate is equal to the second preset threshold and the driving speed of the work vehicle is maintained, the engine target speed is reset if the speed difference is determined to be greater than the preset speed change threshold.

[0022] According to a control method for a work vehicle provided by the present invention, the step of resetting the target engine speed includes:

[0023] If it is determined that the actual engine speed is greater than the target engine speed, and the absolute value of the difference between the actual engine speed and the target engine speed is greater than a first difference, then the target engine speed is reduced.

[0024] If it is determined that the actual engine speed is less than the target engine speed, and the absolute value of the difference between the actual engine speed and the target engine speed is greater than a second difference, the target engine speed is increased.

[0025] In a second aspect, the present invention also provides a control device for a work vehicle, comprising:

[0026] Speed ​​control unit, used to adjust the travel speed of the work vehicle based on engine load rate;

[0027] The speed adjustment unit is used to adjust the engine target speed based on the speed difference between the actual engine speed and the engine target speed, under the condition that a preset condition is met.

[0028] Thirdly, the present invention provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the control method for the work vehicle as described above.

[0029] Fourthly, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the control method for the work vehicle as described in any of the above embodiments.

[0030] Fifthly, the present invention also provides a work vehicle, comprising: a work vehicle body, wherein the work vehicle body is provided with the above-mentioned work vehicle control device or the above-mentioned electronic device or the above-mentioned non-transitory computer-readable storage medium.

[0031] The control method, device, and vehicle for work vehicles provided by this invention can effectively prevent accidents such as engine speed drop or stalling due to overload by monitoring the engine load rate in real time and controlling the driving speed in segments. It can make reasonable use of engine efficiency, greatly improve work efficiency, reduce dependence on driver skills, and prevent damage to work tools and transmission systems due to excessive changes in work load. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 This is one of the flowcharts illustrating the control method for the work vehicle provided by the present invention;

[0034] Figure 2 This is the second flowchart illustrating the control method for the work vehicle provided by the present invention;

[0035] Figure 3 This is a schematic diagram illustrating the principle of adjusting the target engine speed provided by the present invention;

[0036] Figure 4 This is a schematic diagram of the structure of the control device for the work vehicle provided by the present invention;

[0037] Figure 5 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0039] It should be noted that, in the description of the embodiments of the present invention, 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 limitations, 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. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0040] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more.

[0041] Figure 1 This is one of the flowcharts illustrating the control method for the work vehicle provided by the present invention, such as... Figure 1 As shown, including but not limited to the following steps:

[0042] Step 101: Adjust the driving speed of the work vehicle based on the engine load rate;

[0043] It should be noted beforehand that the control method for operating vehicles provided by this invention can be applied to some commonly used construction machinery, such as excavators, loaders, road rollers, concrete mixer trucks, and milling machines, which require both driving and operating functions. For ease of explanation, the following embodiments will use a road milling machine (hereinafter referred to as a milling machine) as an example, which is not considered as a specific limitation on the scope of protection of this invention.

[0044] Among them, the milling machine is one of the main types of machinery for the maintenance and construction of asphalt concrete pavement. It is mainly used for the excavation and renovation of asphalt concrete pavement in highways, urban roads, airports, freight yards, etc. It can also be used to remove defects such as road surface bumps, oil waves, textures, and ruts. It can also be used to excavate road surface potholes and trenches, as well as roughen cement pavement and mill level surface misalignments.

[0045] The execution subject of the control method for the work vehicle provided by the present invention can be an on-board controller.

[0046] Generally, the driver can adjust the acceleration of the milling machine by pushing the driving handle, thereby adjusting the speed of the milling machine.

[0047] The controller can receive the speed increase signal generated in real time after the driver operates the driving handle.

[0048] Furthermore, the controller can respond to the speed increase signal and adjust the driving speed of the work vehicle based on the engine load rate of the work vehicle;

[0049] Specifically, the controller can collect the current engine load rate (which can be referred to as the current load rate) in real time through the engine bus.

[0050] After receiving the speed increase signal, the controller adjusts the vehicle's speed based on the collected engine load rate. Generally, the acceleration required to adjust the vehicle's speed in response to the speed increase signal can be determined based on the different ranges of engine load rate.

[0051] For example, when the engine load is low, the acceleration can be set higher. This can meet the driver's acceleration needs and improve the milling machine's operating efficiency. As the milling machine's speed increases, the engine load will increase accordingly. Therefore, the acceleration can be appropriately reduced based on the increase in engine load to decrease the increase in the milling machine's speed. In other words, adjusting the milling machine's speed is related to its engine load, which can improve the engine's operational stability to some extent.

[0052] Step 102: Under the condition that the preset conditions are met, adjust the engine target speed based on the speed difference between the actual engine speed and the engine target speed.

[0053] The target engine speed can be determined based on the engine speeds obtained from multiple historical sampling periods.

[0054] This invention, while relating the milling machine's travel speed to the engine load rate, achieves smoother engine operation by controlling the engine speed. When the milling machine's workload increases, causing a decrease in the actual engine speed, the target engine speed can be appropriately increased; conversely, when the workload decreases, causing an increase in the actual engine speed, the target engine speed can be correspondingly decreased. This invention uses the aforementioned dynamic setting and adjustment of the engine target speed as auxiliary engine control, which reduces engine speed fluctuations and results in smoother engine operation.

[0055] The target engine speed can be determined based on the engine's historical speed. After each sampling period, the controller sets a target engine speed based on the milling machine's current gear. The target speeds set in previous sampling periods are called historical speeds, while the speed set in the current sampling period is called the target engine speed.

[0056] Specifically, determining that the preset conditions are met can mean that the milling machine is in a stable operating state under engine load. That is, after adjusting the milling machine's travel speed according to the engine load, the milling machine is in a stable operating state.

[0057] The stable operating state can be considered as follows: the acceleration of the milling machine is approximately 0, and the speed of the milling machine is only affected by the working load (which is the milling load from the perspective of the milling machine).

[0058] After determining that the milling machine is in a stable operating state, this invention needs to monitor the change in engine speed in order to determine whether the target engine speed needs to be reset within the current sampling period based on the change in engine speed.

[0059] Monitoring changes in engine speed is typically done by comparing the changes in engine speed within the current sampling period with those within historical sampling periods (such as the average speed over the previous few sampling periods).

[0060] When the change is significant, it is necessary to further determine whether the engine speed has increased or decreased. If it is determined that the engine speed has increased, the target engine speed can be appropriately reduced; if it is determined that the engine speed has decreased, the target engine speed can be appropriately increased to maintain engine speed stability and ensure smoother engine operation.

[0061] The control method for work vehicles provided by this invention can effectively prevent accidents such as engine speed drop or stalling due to overload by monitoring the engine load rate in real time and controlling the driving speed in segments. It can make reasonable use of engine efficiency, greatly improve work efficiency, reduce dependence on driver skills, and prevent damage to work tools and transmission systems due to excessive changes in work load.

[0062] Based on the above embodiments, as an optional embodiment, adjusting the driving speed of the work vehicle based on the engine load rate includes:

[0063] If the engine load rate is determined to be less than a first preset threshold, the driving speed of the work vehicle is increased by a first acceleration based on the speed increase signal.

[0064] The speed increase signal can be a signal received by the controller from the user's operation of the handle.

[0065] Taking a milling machine as an example, the first preset threshold is set to 80%, and the first acceleration is denoted as a1.

[0066] Figure 2 This is the second flowchart illustrating the control method for the work vehicle provided by the present invention, as shown below. Figure 2 As shown, after the controller receives the speed increase signal generated after the driver operates the lever, it compares whether the collected engine load rate is greater than the first preset threshold of 80%.

[0067] If the engine load rate is determined to be less than 80%, it indicates that the milling machine's engine is operating well and can respond to the driver's demand for increased driving speed.

[0068] At this time, the controller adjusts the current of the travel pump control valve and the travel motor control valve to increase the displacement of the travel pump and the travel motor, thereby increasing the travel speed of the milling machine.

[0069] It should be noted that after determining that the engine load rate is less than 80%, the first acceleration for increasing the driving speed can be preset and stored in the controller.

[0070] The entire implementation process can be as follows: After the driver pushes the control lever, if the controller determines that the engine load rate is less than 80% after receiving the speed increase signal, the controller can determine the driving speed according to the following formula:

[0071] V1 = V0 + a1*t;

[0072] Where V1 is the increased driving speed, V0 is the original driving speed, a1 is the first acceleration, and t is the driving time.

[0073] Based on the above embodiments, as an optional embodiment, the adjustment of the vehicle's speed based on engine load rate further includes:

[0074] If the engine load rate is determined to be greater than or equal to a first preset threshold, but less than a second preset threshold, the driving speed of the work vehicle is increased by a second acceleration based on the speed increase signal.

[0075] The second acceleration is less than the first acceleration.

[0076] Taking a milling machine as an example, the range of the second preset threshold is set to 98%-100% (i.e., the second preset threshold includes any value within this range), and the second acceleration is denoted as a2. In other words, the second preset threshold is an interval value (98%-100%). If the engine load rate is any value within the range of 98%-100%, the engine load rate can be considered equal to the second preset threshold. Of course, the second preset threshold can also be set to any value within 98%-100%, such as 98% or 100%, and the second acceleration can be denoted as a2.

[0077] It should be noted that the second preset threshold is generally considered to be the load rate when the engine is under rated load, or it can be considered to be the load rate when the engine is under full load (close to or equal to 100%).

[0078] In this embodiment, when adjusting the driving speed according to the engine load rate, the driver's speed increase signal can be responded to in real time based on the engine load rate collected in the current sampling period to achieve timely adjustment of the driving speed; it can also be implemented after the driving speed of the work vehicle is increased when the engine load rate is less than the first preset threshold as provided in the previous embodiment.

[0079] by Figure 2 As shown in the example, when the engine load rate is less than the first preset threshold, after the driving speed is increased, as the driver continues to push the driving handle to accelerate, the driving speed increases rapidly, and the engine load rate will increase accordingly.

[0080] When the engine load rate increases to a level greater than or equal to the first preset threshold but less than the second preset threshold, it is considered that the engine still has a certain load margin, which can meet the driver's demand for increasing driving speed.

[0081] It should be noted that when the engine load rate is determined to be greater than the first preset threshold (e.g., 80%) but less than the second preset threshold (e.g., 98%), the second acceleration for increasing the driving speed can also be preset and stored in the controller.

[0082] At this point, if the driver continues to push the lever, the controller can determine the driving speed according to the following formula:

[0083] V2 = V1 + a2*t;

[0084] Wherein, V2 is the increased driving speed, V1 is the driving speed before the increase (in this embodiment, it is assumed that after the speed is increased by the first acceleration, the engine load rate is detected to be greater than 80% but less than 98%), a2 is the second acceleration, and t is the driving time.

[0085] Since the engine load rate at this time is higher than that when the speed is increased by the first acceleration, the second acceleration will be less than the first acceleration. That is, by reducing the increase in driving speed, the smoothness of engine operation is improved.

[0086] Based on the above embodiments, as an optional embodiment, the adjustment of the vehicle's speed based on engine load rate further includes:

[0087] If the engine load rate is determined to be equal to the second preset threshold, the speed increase signal is ignored and the driving speed of the work vehicle is maintained.

[0088] In this embodiment, when adjusting the driving speed according to the engine load rate, the driver's speed increase signal can be responded to in real time based on the engine load rate collected in the current sampling period to achieve timely adjustment of the driving speed; or it can operate as provided in the previous embodiment, where the driving speed of the work vehicle is increased after the engine load rate is greater than or equal to a first preset threshold but less than a second preset threshold.

[0089] by Figure 2 As shown in the example, when the engine load rate is greater than or equal to the first preset threshold but less than the second preset threshold, the engine load rate will further increase as the driving speed increases as the driver continues to push the driving handle to accelerate.

[0090] When the engine load rate rises to the second preset threshold (98%-100%), the engine is considered to have reached its operating limit.

[0091] At this time, the engine overload protection function is activated. That is, when the engine load rate is determined to be equal to the second preset threshold, even if the controller receives the speed increase signal generated after the driver pushes the driving handle, the current supplied to the driving pump control valve or driving motor control valve no longer changes. At this time, the driving speed V3 also no longer changes, so that the engine will not slow down and stall due to overload.

[0092] Based on the above embodiments, as an optional embodiment, after maintaining the driving speed of the work vehicle, the following further steps are included:

[0093] If it is determined that the change in the workload of the work vehicle is greater than the load change threshold, the travel speed of the work vehicle is reduced by a third acceleration.

[0094] Combination Figure 2 As shown, if the engine load rate of the milling machine is equal to the second preset threshold, and the travel speed V3 remains unchanged, and the controller detects a sudden increase in the workload (such as milling load), it can reduce the travel speed of the milling machine to reduce the overall workload and alleviate the impact of the workload.

[0095] Specifically, when the engine load rate is determined to be equal to the second preset threshold of 98%, the third acceleration (which is a negative number and can be understood as deceleration) to reduce the driving speed can also be preset and stored in the controller.

[0096] At this point, even if the driver continues to push the control lever, the actual driving speed is determined according to the following formula:

[0097] V4 = V3 - a3t;

[0098] Where V4 is the driving speed after deceleration, V3 is the driving speed before deceleration (in this embodiment, it is assumed that after the speed is increased by the second acceleration, the engine load rate is detected to rise to 98%), a3 is the third acceleration, and t is the driving time.

[0099] Based on the above embodiments, as an optional embodiment, after reducing the driving speed of the work vehicle, the following operations are repeated according to a preset sampling period until the engine load rate equals a second preset threshold:

[0100] Reacquire the engine load rate of the engine;

[0101] If the new engine load rate is determined to be less than the third preset threshold, the driving speed of the work vehicle is increased by the fourth acceleration.

[0102] Combination Figure 2As shown, after the milling machine's travel speed is continuously decelerated according to the third acceleration, the engine load rate will decrease as the travel speed decreases. In order to further improve the working efficiency of the milling machine, when the engine load rate drops from equal to the second preset threshold to less than the third threshold (92%-95%), the travel speed of the milling machine can be increased again. Let the acceleration for increasing the travel speed be the fourth acceleration. At this time, the travel speed is determined according to the following formula:

[0103] V5 = V4 - a4t;

[0104] Where V5 is the increased driving speed, V4 is the driving speed before the increase (in this embodiment, it is assumed that after the speed is reduced by the third acceleration, the engine load rate is detected to drop below the third preset threshold), a4 is the fourth acceleration, and t is the driving time. It should be noted that the third threshold can be set to any value between 92% and 95%, such as 92% or 95%.

[0105] Thus, as the driving speed continues to increase under the fourth acceleration, the engine load rate will increase until it equals the second preset threshold. At this point, it is necessary to keep the driving speed of the working vehicle constant again.

[0106] Throughout the milling machine's operation, the above steps are iteratively executed, maintaining the engine load rate between the second and third preset thresholds. This is achieved by adjusting the current of the travel pump control valve and the travel motor control valve, thus linking the engine load to the travel speed (the travel speed is adjusted to follow changes in the engine load, which can be simply referred to as "load tracking"). This prevents the engine from stalling due to excessive acceleration and avoids fluctuations in travel speed caused by large changes in milling load, which could affect milling efficiency.

[0107] Based on the above embodiments, as an optional embodiment, adjusting the engine target speed based on the speed difference between the actual engine speed and the engine target speed under the predetermined conditions includes:

[0108] If, under the preset condition that the engine load rate is equal to the second preset threshold and the driving speed of the work vehicle is maintained, the engine target speed is reset if the speed difference is determined to be greater than the preset speed change threshold.

[0109] Figure 3 This is a schematic diagram illustrating the principle of adjusting the target engine speed provided by the present invention, as shown below. Figure 3 As shown, the present invention also monitors the actual engine speed in real time, feeds the monitored signal back to the controller, and then ensures that the engine speed fluctuates little and the engine runs smoothly by controlling the target engine speed.

[0110] Optionally, the timing for target speed control can be selected when the engine load rate is equal to the second preset threshold, and the controller response speed increases the signal to maintain the milling machine's travel speed stable (i.e., the preset conditions are met).

[0111] During the period when the speed of the work vehicle remains stable, there are generally fluctuations because the speed is affected to some extent by the workload.

[0112] When the workload increases, the actual engine speed will decrease. The greater the change in workload within a short period of time, the greater the change (denoted as Δ) between the actual engine speed and the target engine speed.

[0113] If Δ is greater than the preset speed change threshold, the engine target speed can be reset by the controller. This invention refers to the reset target speed as the engine target speed, and the original target speed as the engine actual speed.

[0114] Generally speaking, the actual engine speed differs under different milling gears (i.e., different engine target speeds), and the corresponding engine target speed settings will also differ.

[0115] Specifically, when adjusting the target engine speed (such as decreasing or increasing it), the gear of the engine transmission system is automatically adjusted. That is, the speed ratio is adaptively adjusted by automatically adjusting the milling gear to ensure that the adjustment of the target engine speed does not affect the driving speed of the work vehicle or the work load.

[0116] As an optional embodiment, resetting the target engine speed includes:

[0117] If it is determined that the actual engine speed is greater than the target engine speed, and the absolute value of the difference between the actual engine speed and the target engine speed is greater than a first difference, then the target engine speed is reduced.

[0118] If it is determined that the actual engine speed is less than the target engine speed, and the absolute value of the difference between the actual engine speed and the target engine speed is greater than a second difference, the target engine speed is increased.

[0119] Specifically, according to the content described in the previous embodiment, if the change Δ between the actual engine speed collected in the current sampling period and the actual engine speed is greater than the preset speed change threshold, it is assumed that the engine speed of the milling machine fluctuates too much.

[0120] Since the difference between the actual engine speed and the actual rotational speed can manifest in two ways—either the actual speed is lower than the actual engine speed, in which case the engine is operating at underspeed; or the actual speed is higher than the actual engine speed, in which case the engine is operating at overspeed—it is necessary to reset the target speed for each of these different scenarios.

[0121] When the difference Δ between the actual engine speed and the target engine speed is positive and greater than the first difference (denoted as b), adjustment can be made by reducing the target engine speed.

[0122] n 目标 =n' 目标 -d;

[0123] Where, n' 目标 To reduce the actual engine speed before, n 目标 The target engine speed after reduction is given by d, where d is the unit adjustment amount.

[0124] Furthermore, when the difference Δ between the actual engine speed and the actual engine speed is negative, and the absolute value of Δ is greater than the second difference (denoted as c), adjustment can be made by increasing the target engine speed.

[0125] n 目标 =n' 目标 +e;

[0126] Where, n' 目标 n represents the actual engine speed before the boost. 目标 The target engine speed after the increase is indicated by 'e', ​​where 'e' represents the unit adjustment amount.

[0127] It should be noted that different values ​​of the first difference b, the second difference c, and the unit adjustment amounts d and e can be set for different milling gears (i.e., different engine speeds).

[0128] The control method for work vehicles provided by this invention makes the engine run more smoothly by controlling the target engine speed. When the actual engine speed decreases due to increased workload, the target engine speed is increased; when the actual engine speed increases due to decreased workload, the target engine speed is decreased as an auxiliary control of the engine, so that the engine speed fluctuation is small and the engine runs smoothly.

[0129] Figure 4 This is a schematic diagram of the control device for the work vehicle provided by the present invention, as shown below. Figure 4 As shown, it mainly includes a speed control unit 41 and a speed adjustment unit 42, wherein:

[0130] The speed control unit 41 is mainly used to adjust the driving speed of the work vehicle based on the engine load rate;

[0131] The speed adjustment unit 42 is mainly used to adjust the engine target speed based on the speed difference between the actual engine speed and the engine target speed when the preset conditions are met.

[0132] It should be noted that the control device for the work vehicle provided in this embodiment of the invention can execute the control method for the work vehicle described in any of the above embodiments during actual operation, which will not be elaborated in this embodiment.

[0133] The control device for the work vehicle provided by the present invention can effectively prevent the engine from slowing down or stalling due to overload by monitoring the engine load rate in real time and controlling the driving speed in segments. It can make reasonable use of the engine efficiency, greatly improve the work efficiency, reduce the dependence on the driver's skills, and prevent damage to the work tools and transmission system due to excessive changes in the work load.

[0134] The present invention also provides a work vehicle, which mainly includes a work vehicle body; the work vehicle body is provided with a control device for the work vehicle as provided in any of the above embodiments.

[0135] Optionally, the work vehicle provided by the present invention mainly includes: a work vehicle body, wherein a controller, a driving handle, a travel pump, a travel pump displacement control valve, a travel motor, and a travel motor displacement control valve are provided in the work vehicle body.

[0136] It also includes a memory and a program or instructions stored in the memory and executable on the controller, wherein when the program or instructions are executed by the controller, the control method for the work vehicle provided in any of the above embodiments is performed;

[0137] The controller controls the current supplied to the travel pump displacement control valve and the travel motor displacement control valve, thereby controlling the opening degree of the travel pump displacement control valve and the travel motor displacement control valve, and thus controlling the displacement of the travel pump and the travel motor.

[0138] The travel speed of the work vehicle is determined by the displacement of the travel pump, the displacement of the travel motor, and the speed of the engine.

[0139] The work vehicle provided by this invention can control the driving speed in segments by monitoring the engine load rate in real time. This can effectively prevent the engine from slowing down or stalling due to overload, make reasonable use of the engine efficiency, greatly improve work efficiency, reduce dependence on driver skills, and prevent damage to work tools and transmission systems due to excessive changes in work load.

[0140] Figure 5This is a schematic diagram of the structure of the electronic device provided by the present invention, such as... Figure 5 As shown, the electronic device may include a processor 510, a communications interface 520, a memory 530, and a communication bus 540, wherein the processor 510, communications interface 520, and memory 530 communicate with each other via the communication bus 540. The processor 510 can call logical instructions in the memory 530 to execute a control method for the work vehicle, the method including: adjusting the travel speed of the work vehicle based on the engine load rate; and, under predetermined conditions, adjusting the engine target speed based on the speed difference between the actual engine speed and the engine target speed.

[0141] Furthermore, the logical instructions in the aforementioned memory 530 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0142] On the other hand, the present invention also provides a computer program product, the computer program product including a computer program stored on a non-transitory computer-readable storage medium, the computer program including program instructions, when the program instructions are executed by a computer, the computer is able to execute the control method for the work vehicle provided by the above methods, the method including: adjusting the driving speed of the work vehicle based on the engine load rate; and adjusting the engine target speed based on the speed difference between the actual engine speed and the engine target speed when a preset condition is met.

[0143] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the control method for the work vehicle provided in the above embodiments, the method comprising: adjusting the driving speed of the work vehicle based on the engine load rate; and, upon determining that a preset condition is met, adjusting the engine target speed based on the speed difference between the actual engine speed and the engine target speed.

[0144] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The 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 the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0145] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method of a work vehicle, characterized by, include: Adjust the driving speed of the work vehicle based on the engine load rate; Under the premise that the engine load rate is equal to the second preset threshold and the driving speed of the work vehicle is maintained, if the speed difference between the actual engine speed and the engine target speed is greater than the preset speed change threshold, the engine target speed is reset. The method of adjusting the driving speed of the work vehicle based on the engine load rate includes: If the engine load rate is determined to be less than a first preset threshold, the driving speed of the work vehicle is increased by a first acceleration based on the speed increase signal. If the engine load rate is determined to be greater than or equal to a first preset threshold, but less than a second preset threshold, the driving speed of the work vehicle is increased by a second acceleration based on the speed increase signal; wherein the second acceleration is less than the first acceleration. If the engine load rate is determined to be equal to the second preset threshold, the speed increase signal is ignored and the driving speed of the work vehicle is maintained; When it is determined that the change in the workload of the work vehicle is greater than the load change threshold, the speed of the work vehicle is reduced by a third acceleration to prevent sudden changes in workload. The controller automatically controls the speed to decrease. The process of resetting the engine target speed includes: If it is determined that the actual engine speed is greater than the target engine speed, and the absolute value of the difference between the actual engine speed and the target engine speed is greater than a first difference, then the target engine speed is reduced. If it is determined that the actual engine speed is less than the target engine speed, and the absolute value of the difference between the actual engine speed and the target engine speed is greater than a second difference, the target engine speed is increased.

2. The control method of the work vehicle according to claim 1, characterized by, After reducing the speed of the work vehicle, the following operations are repeated according to a preset sampling period until the engine load rate equals a second preset threshold: Reacquire the engine load rate; If the new engine load rate is determined to be less than the third preset threshold, the driving speed of the work vehicle is increased by the fourth acceleration.

3. A control arrangement for a work vehicle, characterized by include: Speed ​​control unit, used to adjust the travel speed of the work vehicle based on engine load rate; The speed adjustment unit is used to reset the engine target speed if, under the preset condition that the engine load rate is equal to the second preset threshold and the driving speed of the work vehicle is maintained, the speed difference between the actual engine speed and the engine target speed is determined to be greater than the preset speed change threshold. The speed control unit is specifically configured to: increase the driving speed of the work vehicle with a first acceleration based on a speed increase signal when the engine load rate is determined to be less than a first preset threshold; increase the driving speed of the work vehicle with a second acceleration based on the speed increase signal when the engine load rate is determined to be greater than or equal to the first preset threshold but less than a second preset threshold, wherein the second acceleration is less than the first acceleration; ignore the speed increase signal and maintain the driving speed of the work vehicle when the engine load rate is determined to be equal to the second preset threshold; and decrease the driving speed of the work vehicle with a third acceleration when the change in the work load of the work vehicle is determined to be greater than a load change threshold, so as to prevent the controller from automatically controlling the driving speed to decrease when the work load changes abruptly. The speed adjustment unit is specifically used to reduce the engine target speed when it is determined that the actual engine speed is greater than the engine target speed and the absolute value of the difference between the actual engine speed and the engine target speed is greater than a first difference. If it is determined that the actual engine speed is less than the target engine speed, and the absolute value of the difference between the actual engine speed and the target engine speed is greater than a second difference, the target engine speed is increased.

4. A work vehicle characterized by, include: The work vehicle body is provided with the control device for the work vehicle as described in claim 3.

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