Land leveler control method, device and equipment

Abstract

The invention provides a land leveler control method, device and equipment, and relates to the technical field of engineering vehicles. The land leveler comprises a continuously variable transmission and an engine, and the method comprises the steps that target driving force needed by the land leveler is determined based on current operation parameters of the land leveler and the target vehicle speed in a target leveling mode; according to the target driving force and the current operation parameters, the target rotating speed and the target torque of the engine are reversely calculated; determining a target speed ratio of the continuously variable transmission according to the target vehicle speed, the target rotating speed and wheel parameters of the land leveler; and controlling operation of the land leveler according to the target rotating speed, the target torque and the target speed ratio. Through real-time continuous adjustment of the speed ratio of the continuously variable transmission and cooperative control of the rotating speed of the engine, decoupling control of the speed stability and the optimal traction output of the land leveler can be achieved, the operation smoothness, the fuel economy and the operation automation level are comprehensively improved, and the leveling operation effect is remarkably improved.

Description

Technical Field

[0001] This application relates to the field of engineering vehicle technology, and in particular to a grader control method, device and equipment. Background Technology

[0002] Graders are core equipment in road construction and site leveling projects. Their precision, efficiency, and operational stability directly determine project quality and construction costs. In leveling operations, graders need to maintain a stable speed according to construction requirements while outputting driving force adapted to load changes to ensure uniform soil cutting depth and a smooth working surface. However, the complex and variable working environment, with real-time fluctuations in parameters such as slope and load, places stringent demands on the grader's power transmission system control.

[0003] In related technologies, the transmission system of graders typically employs a fixed-gear control method, with each gear corresponding to a fixed speed ratio. During operation, the speed and power can be adjusted by switching preset fixed gears. However, using a fixed-gear control method can easily lead to power interruptions and sudden speed changes during gear switching, resulting in poor grading performance. Summary of the Invention

[0004] This application provides a grader control method, device, and equipment to achieve continuous adaptive adjustment of the grader's power and speed ratio, thereby improving the grading operation effect.

[0005] In a first aspect, this application provides a method for controlling a motor grader, the motor grader including a continuously variable transmission (CVT) and an engine, the method comprising:

[0006] Based on the current operating parameters of the grader and the target vehicle speed in the target leveling mode, determine the target driving force required by the grader;

[0007] Based on the target driving force and the current operating parameters, the target speed and target torque of the engine are calculated in reverse.

[0008] The target speed ratio of the continuously variable transmission is determined based on the target vehicle speed, the target rotational speed, and the wheel parameters of the grader.

[0009] The operation of the grader is controlled based on the target rotational speed, the target torque, and the target speed ratio.

[0010] In one possible implementation, the current operating parameters include the current vehicle speed, vehicle mass, and driving resistance; determining the target driving force required by the grader based on the grader's current operating parameters and the target vehicle speed in the target leveling mode includes:

[0011] The current acceleration is determined based on the target vehicle speed, the current vehicle speed, and the speed adjustment time.

[0012] The product of the current acceleration and the total vehicle mass is determined as the acceleration traction force;

[0013] The sum of the accelerating traction force and the driving resistance is determined as the target driving force.

[0014] In one possible implementation, the step of calculating the target speed and target torque of the engine in reverse based on the target driving force and the current operating parameters includes:

[0015] Based on the target driving force, the current vehicle speed, and the continuously variable transmission (CVT) efficiency graph, the target input torque of the CVT is calculated in reverse.

[0016] Based on the target input torque, the target speed of the engine is determined from the universal characteristic curve of the engine, and the fuel consumption rate of the engine at the target speed is less than a preset threshold.

[0017] The target torque of the engine is determined based on the target input torque and the transmission efficiency between the continuously variable transmission and the engine.

[0018] In one possible implementation, the step of calculating the target input torque of the continuously variable transmission (CVT) in reverse, based on the target driving force, the current vehicle speed, and the CVT efficiency map, includes:

[0019] Calculate the target output torque of the continuously variable transmission based on the target driving force and the current vehicle speed;

[0020] Based on the target output torque, the target operating parameters of the continuously variable transmission are determined;

[0021] Based on the target operating parameters, the working efficiency of the continuously variable transmission (CVT) is determined in the CVT efficiency map.

[0022] The target input torque of the continuously variable transmission (CVT) is obtained by performing a reverse calculation based on the working efficiency and the target output torque.

[0023] In one possible implementation, the wheel parameters include a wheel rolling radius correction factor and a rear axle speed ratio; determining the target speed ratio of the continuously variable transmission (CVT) based on the target vehicle speed, the target rotational speed, and the wheel parameters of the grader includes:

[0024] The product of the target vehicle speed, the wheel rolling radius correction coefficient, and the rear axle speed ratio is determined as the transmission speed ratio correction value.

[0025] The ratio of the transmission speed ratio correction value to the target speed is determined as the target speed ratio.

[0026] In one possible implementation, controlling the operation of the grader based on the target rotational speed, the target torque, and the target speed ratio includes:

[0027] Send a speed adjustment command to the engine controller so that the engine controller adjusts the current speed of the engine to the target speed according to the speed adjustment command;

[0028] A torque adjustment command is sent to the engine controller so that the engine controller adjusts the current torque of the engine to the target torque according to the torque adjustment command;

[0029] A speed ratio adjustment command is sent to the actuator of the continuously variable transmission (CVT) so that the actuator adjusts the current speed ratio of the CVT to the target speed ratio according to the speed ratio adjustment command.

[0030] In one possible implementation, the method further includes:

[0031] During the operation of the grader, the slip ratio of each wheel is calculated, which reflects the degree of wheel slippage.

[0032] For any wheel, if the slip ratio of the wheel is greater than a preset slip ratio threshold, the target torque of the engine is reduced to a safe threshold, and the target speed ratio is increased to a safe speed ratio. The safe speed ratio is determined based on the target speed ratio and the difference between the slip ratio and the preset slip ratio threshold.

[0033] Secondly, this application provides a grader control device, the device comprising:

[0034] The first processing module is used to determine the target driving force required by the grader based on the current operating parameters of the grader and the target vehicle speed in the target leveling mode.

[0035] The reverse calculation module is used to reverse calculate the target speed and target torque of the engine based on the target driving force and the current operating parameters;

[0036] The second processing module is used to determine the target speed ratio of the continuously variable transmission based on the target vehicle speed, the target rotational speed, and the wheel parameters of the grader.

[0037] The control module is used to control the operation of the grader based on the target rotational speed, the target torque, and the target speed ratio.

[0038] Thirdly, this application provides a controller, including: a memory and a processor;

[0039] The memory stores computer-executed instructions;

[0040] The processor executes computer execution instructions stored in the memory, causing the processor to perform the method as described in any of the first aspects.

[0041] Fourthly, this application provides a grader, comprising: an engine, an engine controller, a continuously variable transmission, an actuator, and a controller as described in the third aspect;

[0042] The engine is connected to the continuously variable transmission and the engine controller, respectively.

[0043] The continuously variable transmission is connected to the actuator;

[0044] The controller is connected to the actuator and the engine controller respectively.

[0045] Fifthly, this application provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the method described in any of the first aspects above.

[0046] In a sixth aspect, this application provides a computer program product, including a computer program that, when executed by a processor, implements the method described in any of the first aspects above.

[0047] This application provides a grader control method, device, and equipment. The core of the method lies in configuring a continuously variable transmission (CVT) and an engine within the grader to execute the following control logic: Based on the grader's current operating parameters and the target speed in the target leveling mode, the required target driving force is determined; based on the target driving force and current operating parameters, the target engine speed and target torque are calculated in reverse; combining the target vehicle speed, the engine's target speed, and the grader's wheel parameters, the target gear ratio of the CVT is determined; finally, based on the engine's target speed, target torque, and the CVT's target gear ratio, precise control of the grader's operation is achieved. This solution, based on the real-time continuous adjustment of the CVT gear ratio and the coordinated control of the engine speed, can achieve decoupled control of the grader's speed stability and optimal traction output, significantly improving the leveling operation effect. Attached Figure Description

[0048] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0049] Figure 1A schematic diagram illustrating the application scenarios provided in the embodiments of this application;

[0050] Figure 2 A flowchart illustrating an embodiment of the grader control method provided in this application;

[0051] Figure 3 A flowchart illustrating Embodiment 2 of the grader control method provided in this application;

[0052] Figure 4 A flowchart illustrating Embodiment 3 of the grader control method provided in this application;

[0053] Figure 5 A flowchart illustrating an example of the grader control method provided in this application;

[0054] Figure 6 This is a schematic diagram of the structure of the grader control device provided in the embodiments of this application;

[0055] Figure 7 This is a schematic diagram of the controller provided in an embodiment of this application;

[0056] Figure 8 This is a schematic diagram of the structure of the grader provided in the embodiments of this application.

[0057] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0058] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0059] As a core construction equipment in road construction, site leveling, and earthwork engineering, graders operate in complex and variable environments, frequently facing challenges such as load fluctuations, terrain undulations, and material density differences. For example, in road base leveling, graders need to maintain a stable operating speed while adjusting traction in real time based on scraping resistance to avoid work interruptions due to sudden speed drops or blade slippage caused by insufficient traction. Furthermore, in areas with frequently changing slopes, graders need to dynamically balance engine output and transmission system efficiency, preventing fuel waste from high engine speeds while avoiding decreased operational accuracy due to power transmission lag.

[0060] In related technologies, the transmission control of graders relies on a fixed gear structure, with a one-to-one correspondence between gears and speed ratios. Operators need to adjust the vehicle speed and power by switching gears. However, this control mode based on discrete gears cannot achieve continuous power transmission during gear switching, which can easily cause sudden increases or decreases in vehicle speed and a break in power connection, resulting in poor grading performance.

[0061] To address the aforementioned issues, this paper proposes introducing a continuously variable transmission (CVT) and constructing a collaborative control architecture that integrates load demand, engine parameter control, and gear ratio adjustment. This replaces the traditional discrete transmission mode with fixed gears, creating a grader control scheme that combines continuous power delivery with precise adaptation. This achieves the dual goals of stable vehicle speed and efficient power matching during grading operations. Based on this, the inventors discovered through numerous experiments that the target driving force to meet real-time load requirements can be calculated first based on the grader's current operating parameters (such as vehicle weight, gradient, and driving resistance) and the target vehicle speed under the target grading mode. Then, using the target driving force as the core, the target engine speed and torque are derived in reverse, ensuring the engine always operates within its efficient power output range. Finally, leveraging the continuously adjustable gear ratio of the CVT, the target gear ratio of the CVT is dynamically determined and adjusted according to the target vehicle speed, target engine speed, and wheel parameters. The controller then collaboratively manages the operating states of the engine and the CVT. In the aforementioned process, replacing the fixed-gear structure with a continuously variable transmission (CVT) reduces power interruption issues caused by gear shifting, achieving continuous and smooth power transmission and fundamentally preventing sudden increases or decreases in vehicle speed. Simultaneously, through a closed-loop logic of "target driving force positioning, engine parameter matching, and dynamic speed ratio adaptation," the power output is always precisely matched to the workload requirements. This solves the problem of power-load mismatch in traditional fixed-gear systems and ensures a stable vehicle speed required for leveling operations, improving operational accuracy and efficiency. Based on this, this application proposes a grader control method, aiming to improve the leveling performance of graders through the introduction of a CVT and its collaborative control design.

[0062] Figure 1 This is a schematic diagram illustrating an application scenario provided in an embodiment of this application. Please refer to [link / reference]. Figure 1 The sensor array can transmit current operating parameters to the grader's controller, and the target leveling mode can provide the target vehicle speed to the controller. The grader contains a controller, an engine, and a continuously variable transmission (CVT). After receiving the aforementioned current operating parameters and target vehicle speed, the controller can output the target speed and target torque to the engine and the target speed ratio to the CVT to control the operation of the grader.

[0063] The technical solution of this application and how it solves the above-mentioned technical problems will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0064] Figure 2 This is a flowchart illustrating an embodiment of the grader control method provided in this application. Please refer to [link / reference]. Figure 2 The grader includes a continuously variable transmission (CVT) and an engine, and the grader control method may include:

[0065] S201. Based on the current operating parameters of the grader and the target vehicle speed in the target leveling mode, determine the target driving force required by the grader.

[0066] The execution entity in this application embodiment can be a controller or a grader control device installed in the controller. The grader control device can be implemented by software or by a combination of software and hardware. The grader control device can be a processor in the controller. For ease of understanding, the technical solution of this application will be described below using a controller as an example.

[0067] In this step, the controller can obtain the current operating parameters based on the sensor group pre-set in the grader, determine the target leveling mode according to the operator's selection of the grader's working mode on the grader's human-machine interface (HMI), and then determine the target driving force required by the grader based on the current operating parameters and the target vehicle speed in the target leveling mode.

[0068] The current operating parameters of the grader may include, but are not limited to: the current engine speed, current load torque, current throttle opening, current input torque and current output torque of the continuously variable transmission, current gradient, current vehicle speed, vehicle weight, and driving resistance.

[0069] Optionally, the grader's operating modes can include fine grading mode, efficient transfer mode, and manual mode. For example, users can select fine grading mode as the grader's operating mode (i.e., target grading mode) in the grader's HMI.

[0070] Furthermore, after determining the target leveling mode, the corresponding target vehicle speed can be set manually in this mode, or the default value built into the mode can be used directly as the target vehicle speed for the current operation, so as to adapt to the operation requirements in different scenarios.

[0071] In one specific implementation, the target driving force required by the grader can be determined based on the current vehicle speed, vehicle mass, and driving resistance included in the current operating parameters, combined with the target vehicle speed. Specifically, this can include the following steps ①②③.

[0072] Step 1: Determine the current acceleration based on the target vehicle speed, the current vehicle speed, and the speed adjustment time.

[0073] Specifically, it can be based on the target vehicle speed. Current vehicle speed and preset speed adjustment time Calculate the current acceleration required for the grader to track the target vehicle speed. The calculation formula is:

[0074] Formula (1)

[0075] In formula (1), the value of this acceleration directly reflects the rate requirement for the grader to adjust from the current speed to the target speed; speed adjustment time It can be calibrated according to actual working conditions and driving comfort requirements.

[0076] Step 2: Determine the product of the current acceleration and the total mass of the vehicle as the acceleration traction force.

[0077] Specifically, the current acceleration can be... Multiplying the total mass M of the grader by the acceleration traction force gives the acceleration traction force. The calculation formula is:

[0078] Formula (2)

[0079] In formula (2), Its function is to overcome the inertial resistance generated by the grader during speed adjustment, and it is a power component for maintaining the target vehicle speed.

[0080] Step 3: Determine the target driving force as the sum of the acceleration traction force and the driving resistance.

[0081] Specifically, it can accelerate traction. Adding this to the driving resistance R (i.e., the current ground resistance) estimated by the controller, we obtain the target driving force required for the grader to maintain the target speed. The calculation formula is:

[0082] Formula (3)

[0083] Regarding the driving resistance R, a vehicle dynamics model can be used, combining the vehicle mass M, the current slope α, the rolling resistance coefficient f, and the air resistance coefficient. Estimate the current operating parameters.

[0084] S202. Based on the target driving force and current operating parameters, calculate the target speed and target torque of the engine in reverse.

[0085] In this step, the target engine speed and target torque can be calculated in reverse based on the target driving force required to maintain the target vehicle speed and the current vehicle speed in the current operating parameters.

[0086] In practice, the target input torque of the continuously variable transmission (CVT) can be calculated in reverse based on the target driving force, current vehicle speed, and CVT efficiency graph. Based on the target input torque, the target engine speed is determined from the engine's universal characteristic curve, and the engine's fuel consumption rate at the target speed is less than a preset threshold. Then, the target engine torque can be determined based on the target input torque and the transmission efficiency between the CVT and the engine.

[0087] The Variable Transmission (CVT) Efficiency Map (MAP) is a two-dimensional characteristic map obtained through bench testing, representing the CVT's transmission efficiency under different operating conditions. The horizontal axis of the map represents the CVT's speed ratio, and the vertical axis represents the CVT's output torque. The value corresponding to each coordinate point in the map is the transmission efficiency under that operating condition (range 0-1). This map covers efficiency data across the entire speed ratio range and torque load range of the transmission, meeting the operating requirements of all work modes for graders, including fine leveling and efficient site transfer.

[0088] Specifically, it can be combined with goal-driven forces. With current vehicle speed The output torque of the drive wheels is derived through vehicle dynamics, and then the target output torque of the CVT is calculated in reverse. The calculation formula is:

[0089] Formula (4)

[0090] In formula (4), r represents the radius of the drive wheel. Indicates the final drive ratio. This indicates the efficiency of the main reducer.

[0091] The efficiency graph of the continuously variable transmission (CVT) has been pre-calibrated, with the horizontal axis representing the speed ratio. The vertical axis represents the output torque. The node value is the transmission efficiency. Combined with the target output torque of the CVT It can match the optimal speed ratio of the CVT. The optimal speed ratio The transmission efficiency is highest under high torque conditions, which allows us to determine the target operating parameters of the CVT, including the optimal speed ratio. .

[0092] Furthermore, it can be based on the optimal speed ratio and the target output torque of the CVT Determine the transmission efficiency of the continuously variable transmission (CVT) in the CVT efficiency graph. Finally, based on the law of conservation of energy, the input torque needs to compensate for transmission efficiency losses to obtain the target input torque of the CVT. The calculation formula is:

[0093] Formula (5)

[0094] The universal characteristic curve of an engine refers to a two-dimensional characteristic graph plotted with engine speed as the abscissa, output torque as the ordinate, and isopleths representing constant fuel consumption rates. Similarly, this curve can be obtained through engine bench testing and calibration, covering operating data across the entire engine speed and torque load range. The closed isopleths representing constant fuel consumption rates in the graph are elliptical in shape; the closer the isopleths are to the center, the lower the fuel consumption rate under the corresponding speed-torque condition.

[0095] In one specific implementation, since the CVT and the engine are connected via transmission components (such as couplings and clutches), the target input torque of the CVT is essentially the load torque that the engine needs to overcome. Therefore, the engine output torque must at least meet the target input torque of the CVT. The corresponding power requirements. Based on the application logic of the engine's universal characteristic curve, the target speed... The determination process may include:

[0096] Step ①: Target input torque for CVT Based on this, and taking into account the fundamental losses of the transmission system, the torque range that the engine needs to cover is determined.

[0097] Step 2: In the engine's universal characteristic curve, find all speed points within the aforementioned torque range that satisfy the condition of "fuel consumption rate less than a preset threshold". The preset threshold can be pre-calibrated based on the economic requirements of the grader operation. For example, in fine leveling mode, the preset threshold can be set to 220 grams per kilowatt-hour. .

[0098] Step 3: Select the engine speed with the lowest fuel consumption rate from the eligible speed points as the target engine speed. For example, if within the torque matching range, the fuel consumption rate corresponding to an engine speed of 1500 r / min is 210. The fuel consumption rate corresponding to 1600 r / min is 215. Both are less than 220 If so, 1500r / min is selected as the target speed to ensure that the engine achieves optimal fuel economy while meeting power requirements.

[0099] It should be noted that the target input torque of the CVT This is the effective torque after the engine's output torque has been transmitted through transmission components (couplings, bearings, etc.). Since energy loss is unavoidable during transmission, the engine's actual output torque must be greater than [the required torque]. This is to compensate for the loss.

[0100] Specifically, the engine's target torque The specific determination process is as follows:

[0101] First, the transmission efficiency between the CVT and the engine can be determined. This efficiency The overall transmission efficiency of the transmission components can be pre-calibrated through bench testing, with a value ranging from 0 to 1.

[0102] Subsequently, the target torque that the engine needs to output can be derived in reverse based on the law of conservation of energy. The calculation formula is:

[0103] Formula (6)

[0104] S203. Determine the target speed ratio of the continuously variable transmission (CVT) based on the target vehicle speed, target rotational speed, and wheel parameters of the grader.

[0105] In this step, the controller can deduce the target speed ratio of the continuously variable transmission (CVT) based on the grader's target speed, the engine's target speed, and pre-calibrated wheel parameters, through the speed matching relationship of the powertrain, to ensure that the engine output speed can be accurately converted into the vehicle speed that meets the work requirements.

[0106] In one optional implementation, the wheel parameters may include a wheel rolling radius correction coefficient and a rear axle ratio. Based on the target vehicle speed, target speed, and wheel parameters of the grader, the target gear ratio of the continuously variable transmission (CVT) is determined. Specifically, this may include: determining the transmission ratio correction value as the product of the target vehicle speed, the wheel rolling radius correction coefficient, and the rear axle ratio; and determining the target gear ratio as the ratio of the transmission ratio correction value to the target speed.

[0107] The wheel rolling radius correction coefficient K is used to correct the deviation between the actual and theoretical rolling radius of the drive wheel (caused by factors such as ground compaction and tire pressure). It can be pre-calibrated through field tests, with a value range of 0.98 to 1.02; rear axle speed ratio. The fixed reduction ratio of the main reducer (i.e., the main reduction ratio) is an inherent parameter of the grader's transmission system, determined by the vehicle's design parameters.

[0108] Specifically, transmission ratio correction value The calculation formula is:

[0109] Formula (7)

[0110] Specifically, the target speed ratio of CVT The calculation formula is:

[0111] Formula (8)

[0112] S204. Control the operation of the grader according to the target speed, target torque, and target speed ratio.

[0113] In this step, the controller can send precise adjustment commands to the engine controller and the actuators of the continuously variable transmission (CVT) to achieve coordinated linkage between engine power output and CVT speed ratio adjustment, ensuring that the grader operates stably at the target speed.

[0114] In one specific implementation, the controller can simultaneously send a speed adjustment command and a torque adjustment command to the engine controller. The speed adjustment command carries the target speed of the engine, and the torque adjustment command carries the target torque of the engine. After receiving the above two commands, the engine controller can adjust the engine's core control parameters such as fuel injection quantity and throttle opening to simultaneously drive the engine's crankshaft speed to converge from the current speed to the target speed and the output torque to converge from the current torque to the target torque.

[0115] At the same time, the controller can send a speed ratio adjustment command to the actuator of the continuously variable transmission (CVT). This speed ratio adjustment command carries the target speed ratio of the CVT. After receiving the speed ratio adjustment command, the actuator of the CVT can adjust the current speed ratio of the CVT to the target speed ratio by adjusting its own core control parameters, thereby realizing the coordinated linkage between engine power output and CVT speed ratio adjustment.

[0116] Optionally, the actuator of the continuously variable transmission can be an electro-hydraulic proportional valve or an electronically controlled actuator. The electro-hydraulic proportional valve can drive the active cone and / or driven cone to move by receiving a speed ratio adjustment command (such as a current command), thereby changing the working radius ratio and making the current speed ratio quickly and smoothly approach the target speed ratio. The electronically controlled actuator can adjust the speed ratio by driving the adjustment structure with a motor, ensuring the accuracy and continuity of the speed ratio adjustment.

[0117] In this embodiment, the controller can determine the target driving force required by the grader based on its current operating parameters and the target vehicle speed in the target leveling mode; it can then calculate the target engine speed and target torque based on the target driving force and current operating parameters; and it can determine the target gear ratio of the continuously variable transmission (CVT) based on the target vehicle speed, target speed, and wheel parameters of the grader. Finally, it controls the operation of the grader based on the target speed, target torque, and target gear ratio. The grader includes a CVT and an engine. In the above process, the CVT's continuous gear ratio adjustment and engine coordinated control can decouple vehicle speed and traction, reducing power interruptions and sudden speed changes associated with traditional gear shifting, ensuring operational efficiency and reducing energy consumption.

[0118] Figure 3 This is a flowchart illustrating a second embodiment of the grader control method provided in this application. Please refer to [link / reference]. Figure 3 The current operating parameters include the current vehicle speed. The specific implementation of step S202 may also include the following steps:

[0119] S301. Based on the target driving force, current vehicle speed, and continuously variable transmission (CVT) efficiency graph, calculate the target input torque of the CVT in reverse.

[0120] In this step, the target output torque of the continuously variable transmission (CVT) can be derived by using reverse thinking, based on the target driving force required to maintain the target vehicle speed and the current vehicle speed in the current operating parameters; based on the target output torque, the target operating parameters of the CVT are determined; based on the target operating parameters, the working efficiency of the CVT is determined in the CVT efficiency map; and based on the working efficiency and the target output torque, the target input torque of the CVT is obtained by reverse calculation.

[0121] Among them, the driving force of the goal To maintain stable tracking of the target vehicle speed by the grader in target leveling mode The total driving force required at the wheel end is determined by the forces required to overcome the current ground resistance (driving resistance R) and achieve the target acceleration. The acceleration requirements are jointly determined and can be calculated based on current operating parameters (such as vehicle mass M, current gradient α, etc.).

[0122] In one specific implementation, the target output torque of the CVT can be derived by combining the vehicle dynamics transmission path. In specific implementation, the target driving force at the wheel edge The driving force needs to act on the ground through the drive wheels, and the torque of the drive wheels is transmitted from the CVT through the final drive reducer. Therefore, the target driving force at the wheel side needs to be... This is then converted into the torque requirement at the CVT output.

[0123] For example, the target driving force can be calculated using the formula shown in formula (4). Drive wheel radius r, final drive reduction ratio and the efficiency of the main reducer The target output torque of the CVT is calculated. .

[0124] Furthermore, after determining the target output torque of the CVT... After that, the target output torque can be determined. The target operating parameters of the CVT are determined. These target operating parameters are the optimal speed ratio of the CVT. .

[0125] Specifically, based on the pre-calibrated efficiency map of the continuously variable transmission (CVT), while meeting the target output torque... Under the premise of meeting the requirements, the speed ratio with the highest transmission efficiency is selected as the optimal speed ratio. During the matching process, the target output torque is used first. As a constraint on the vertical axis, locate the speed ratio range corresponding to this torque in the continuously variable transmission (CVT) efficiency graph; simultaneously, consider the current vehicle speed. Assisted filtering. Due to current vehicle speed This corresponds to a specific CVT output speed, and the CVT output speed is negatively correlated with the speed ratio (when the input speed is fixed, the larger the speed ratio, the smaller the output speed). Therefore, it can be adjusted according to the current vehicle speed. By determining the corresponding CVT output speed range, the speed ratio selection range can be narrowed down, improving matching efficiency and accuracy. Finally, within the selected speed ratio range, the transmission efficiency value corresponding to each speed ratio can be extracted, and the speed ratio with the highest transmission efficiency can be selected as the optimal speed ratio of the CVT. .

[0126] It should be noted that as the grader's current speed approaches the target speed, the optimal gear ratio and the target gear ratio exhibit a dynamic and coordinated adaptation relationship. Both work together to ensure smooth power transmission and optimal transmission efficiency. The optimal gear ratio is a benchmark gear ratio obtained based on the continuously variable transmission (CVT) efficiency map, with the core objective of "meeting the target output torque and maximizing transmission efficiency." It is updated synchronously as the current speed approaches the target speed. When the current speed deviates significantly from the target speed (such as during acceleration), the target output torque requirement is high, and the optimal gear ratio can be matched to a high-efficiency value within the low speed ratio range to achieve high torque output. Conversely, as the current speed gradually approaches the target speed (such as during a smooth approach phase), the target output torque requirement decreases, and the optimal gear ratio can be dynamically adjusted to a high-efficiency value within the corresponding torque range, consistently providing an efficient benchmark for power transmission.

[0127] The target speed ratio is the execution speed ratio obtained by further calibrating the optimal speed ratio, taking into account "the rate at which the current vehicle speed approaches the target speed and the deviation between the current engine speed and the target speed". It is the core parameter for the actual adjustment of the CVT. During the process of the current vehicle speed approaching the target speed, the target speed ratio is constrained by the optimal speed ratio and achieves a balance between "smooth speed approach" and "optimal efficiency" through continuous small adjustments.

[0128] Furthermore, the operating efficiency of the continuously variable transmission (CVT) can be determined. In practice, this can be achieved through the optimal speed ratio. and target output torque Using coordinate combinations, the corresponding operating condition node is precisely located in the continuously variable transmission (CVT) efficiency graph. The value corresponding to this node represents the CVT's operating efficiency under the current operating condition. .

[0129] In one alternative implementation, if the coordinate combination falls between discrete nodes of the graph, the working efficiency can be calculated using linear interpolation to ensure the accuracy of the efficiency value and provide a reliable basis for the subsequent reverse calculation of the input torque.

[0130] Finally, based on the law of conservation of energy, the target output torque can be determined... Compared with the current operating conditions, the efficiency of CVT The target input torque for the continuously variable transmission (CVT) is determined. .

[0131] S302. Based on the target input torque, determine the target engine speed in the engine's universal characteristic curve, and ensure that the engine's fuel consumption rate at the target speed is less than a preset threshold.

[0132] In this step, while meeting the target input torque power requirements of the continuously variable transmission, the optimal speed with a fuel consumption rate that meets the preset threshold requirement can be selected based on the engine's universal characteristic curve, thus achieving a balance between power and fuel economy during grader operation.

[0133] In one specific implementation, the torque adaptation range of the engine can be determined first based on the target input torque. Within this range, the speed-torque operating points corresponding to the universal characteristic curve of the engine are traversed, and the operating points with a fuel consumption rate less than a preset threshold are selected. The selected operating points are statistically analyzed, and the speed corresponding to the operating point with the lowest fuel consumption rate is selected as the target speed of the engine.

[0134] Because the CVT is rigidly connected to the engine through transmission components such as couplings and clutches, the target input torque of the CVT... This refers to the core load torque that the engine needs to overcome. Considering the mechanical friction losses in the transmission components, the engine output torque needs to be slightly higher than this target input torque. .

[0135] In one specific implementation, the target input torque of the CVT can be... As a benchmark, multiplying by a preset loss compensation coefficient n yields the minimum output torque that the engine needs to cover; simultaneously, combined with the engine's maximum output torque limit, the engine's torque adaptation range is determined. The loss compensation coefficient n can be calibrated through bench tests of transmission components, with a value ranging from 1.02 to 1.05.

[0136] Furthermore, within the defined torque matching range, all corresponding speed-torque operating points can be traversed to filter out operating points with fuel consumption rates less than a preset threshold, and the speed corresponding to the operating point with the lowest fuel consumption rate can be selected as the engine target speed.

[0137] Optionally, if multiple speeds correspond to the same minimum fuel consumption rate, the speed closest to the engine's commonly used economic speed range can be selected to ensure the engine's stability and durability.

[0138] S303. Determine the target torque of the engine based on the target input torque and the transmission efficiency between the continuously variable transmission and the engine.

[0139] In this step, the energy loss of the transmission components between the engine and the continuously variable transmission (CVT) can be compensated based on the energy conservation principle, and the engine target torque that meets the CVT target input torque requirement can be derived in reverse.

[0140] In one specific implementation, the transmission efficiency between the continuously variable transmission (CVT) and the engine can be determined, and then the target torque of the engine can be determined based on the ratio between the target input torque and the transmission efficiency.

[0141] The transmission efficiency between the continuously variable transmission (CVT) and the engine is the overall transmission efficiency of the transmission components, which can include the efficiency attenuation corresponding to the friction loss and mechanical clearance loss of transmission components such as couplings (clutches) and bearings.

[0142] In this embodiment, the controller can calculate the target input torque of the continuously variable transmission (CVT) based on the target driving force, current vehicle speed, and CVT efficiency graph. Based on the target input torque, the controller determines the target engine speed from the engine's universal characteristic curve, ensuring that the engine's fuel consumption rate at that target speed is less than a preset threshold. The controller also determines the target engine torque based on the target input torque and the transmission efficiency between the CVT and the engine. In this process, the engine's universal characteristic curve can be used to select target speeds with fuel consumption rates below the preset threshold, effectively reducing fuel consumption while meeting the power requirements of the grader.

[0143] Figure 4 This is a flowchart illustrating Embodiment 3 of the grader control method provided in this application. Please refer to [link / reference]. Figure 4 Based on any of the above embodiments, the grader control method further includes:

[0144] S401. During the operation of the grader, calculate the slip ratio of each wheel.

[0145] In this step, the controller continuously collects the wheel speed signals of each drive wheel and the overall vehicle speed signal of the grader during its leveling operation. Based on a preset slip ratio calculation formula, it calculates the slip ratio of each drive wheel in real time. The slip ratio reflects the degree of wheel slippage and characterizes the deviation between the actual rolling linear velocity of the drive wheel and the actual vehicle speed.

[0146] Specifically, slip ratio The calculation formula is:

[0147] Formula (9)

[0148] In formula (9), This represents the real-time slip ratio of a single drive wheel, expressed as a percentage. The estimated vehicle speed for the grader is the actual speed of the grader during its actual operation. This speed can be obtained from the vehicle speed sensor and is the same parameter used in the calculation of the target driving force and the continuously variable transmission speed ratio mentioned earlier. The actual rolling linear velocity of a single drive wheel is calculated from the wheel speed signal collected by the drive wheel speed sensor.

[0149] In one optional implementation, the slip ratio is calculated in a high-frequency closed-loop operation mode. The calculation period can be matched with the sampling period of the controller, with a value of 10~100ms. This can quickly capture the slip state changes of each drive wheel, accurately reflect the adhesion matching between the drive wheel and the ground, and provide timely and reliable judgment basis for subsequent slip intervention actions.

[0150] S402. For any wheel, if the wheel slip ratio is greater than the preset slip ratio threshold, reduce the engine's target torque to the safe threshold and increase the target speed ratio to the safe speed ratio.

[0151] In this step, the controller compares the real-time calculated slip ratio of each drive wheel with a preset slip ratio threshold. For any drive wheel, if its slip ratio exceeds the preset slip ratio threshold, the controller immediately reduces the engine's target torque to a safe threshold and instantaneously increases the continuously variable transmission's target gear ratio to a safe gear ratio. The safe gear ratio is determined based on the target gear ratio and the difference between the slip ratio and the preset slip ratio threshold.

[0152] The preset slip ratio threshold is the anti-slip trigger threshold under grader leveling operations, calibrated through field operation tests. For example, the preset slip ratio threshold... The threshold of 20% balances the timeliness of anti-skid response with the smoothness of control, avoiding frequent intervention actions caused by slight fluctuations in the slip ratio due to minor road bumps.

[0153] Specifically, safe gear ratio The calculation formula is:

[0154] Formula (10)

[0155] In formula (10), This represents the preset proportional gain coefficient, which is a fixed value after actual calibration. = - , which is the difference between the slip rate of the current drive wheel and the preset slip rate threshold.

[0156] Optionally, the engine's target speed can also be limited to a safe value to quickly suppress wheel slippage, restore effective traction of the drive wheels, and ensure power transmission efficiency and speed stability during grader operation.

[0157] For example, regarding drive wheel A, if the slip ratio of drive wheel A... Greater than the preset slip ratio threshold Then the controller can target the engine torque. The controller performs a momentary downward adjustment, initiating a torque reduction request. In practice, the controller can adjust the engine's target torque... The torque threshold is instantly reduced to a torque limit that meets the anti-slip requirements. This torque limit can effectively reduce the driving torque of the drive wheels, directly suppressing the wheel slippage tendency from the source of power output, and avoiding further aggravation of slippage due to excessive power output.

[0158] At the same time, the controller can increase the target speed ratio of the continuously variable transmission (CVT). To the safe speed ratio Increasing the target speed ratio can improve the gear ratio of the continuously variable transmission (CVT), effectively increasing the wheel torque potential. At the same time, this action works in synergy with the engine's torque reduction action, which can quickly eliminate the slippage problem of the drive wheels and also meet the traction requirements of the grader, achieving the dual effect of preventing slippage and maintaining power.

[0159] Optionally, while executing the engine torque reduction and continuously variable transmission (CVT) speed ratio, the controller can also set the target engine speed. Implement upper limit control to restrict the target engine speed. The engine speed should not exceed the preset safe speed limit. This limit control can avoid power redundancy caused by excessive engine speed and further reduce the risk of drive wheel slippage.

[0160] Furthermore, after executing the aforementioned slippage intervention actions, the controller can continue to calculate and monitor the real-time slippage rate of each drive wheel at a high-frequency cycle of 10-100ms. The controller will continue until the slippage rate of all drive wheels falls back to the preset safe slippage rate threshold. When the slippage of the drive wheels is effectively eliminated, the safe slippage rate threshold is preferably set to 15%. At this point, the controller can gradually cancel all slippage intervention actions, gradually restore the original target torque of the engine and the original target speed ratio of the continuously variable transmission according to a gentle gradient, and simultaneously remove the limit control on the target engine speed until all control parameters are restored to the initial control target values ​​before the slippage intervention actions were triggered.

[0161] In this embodiment, during the operation of the grader, the controller can calculate the slip ratio of each wheel. For any wheel, if the slip ratio exceeds a preset slip ratio threshold, the target torque of the engine is reduced to a safe threshold, and the target speed ratio is increased to a safe speed ratio. Through the above-mentioned slip ratio monitoring and coordinated intervention, the controller can quickly and accurately suppress the slippage of the drive wheels, effectively restore the adhesion between the drive wheels and the ground, and avoid problems such as ineffective power loss and abnormal tire wear caused by wheel slippage.

[0162] Figure 5The flowchart illustrates an example of the grader control method provided in this application. Please refer to [link / reference]. Figure 5 It can include:

[0163] S501, Data Acquisition.

[0164] Specifically, the controller can continuously acquire the current operating parameters of the grader during its operation.

[0165] S502, Determine the target decision.

[0166] Specifically, the controller can determine the target leveling mode based on the operator's selection of the grader's working mode on the grader's HMI interface, and then manually set the corresponding target speed in the target leveling mode, or directly use the default value of the target leveling mode as the target speed for the current operation.

[0167] S503, estimate driving resistance and calculate acceleration traction.

[0168] Specifically, the driving resistance can be estimated by using a vehicle dynamics model, combined with current operating parameters such as vehicle mass, current slope, rolling resistance coefficient, and air resistance coefficient; based on the target vehicle speed, current vehicle speed, and preset speed adjustment time, the current acceleration required for the grader to track the target vehicle speed can be determined, and then the acceleration traction force can be calculated based on the current acceleration and the total vehicle mass.

[0169] S504. Determine the target driving force required for the grader.

[0170] Specifically, the sum of the accelerating traction force and the driving resistance can be determined as the target driving force.

[0171] S505, Determine the target engine speed and target torque.

[0172] Specifically, the target engine speed and target torque can be calculated in reverse based on the target driving force and current operating parameters.

[0173] S506. Determine the target speed ratio of the continuously variable transmission (CVT).

[0174] Specifically, the target gear ratio of the continuously variable transmission (CVT) can be determined based on the target vehicle speed, target engine speed, and wheel parameters of the grader.

[0175] S507, continuously variable transmission (CVT) with adjustable gear ratio.

[0176] Specifically, a speed ratio adjustment command can be sent to the actuator of the continuously variable transmission (CVT) so that the actuator can adjust the current speed ratio of the CVT to the target speed ratio according to the speed ratio adjustment command.

[0177] S508, engine speed and torque coordinated control.

[0178] Specifically, a speed adjustment command can be sent to the engine controller so that the engine controller adjusts the current engine speed to the target speed according to the speed adjustment command; a torque adjustment command can be sent to the engine controller so that the engine controller adjusts the current engine torque to the target torque according to the torque adjustment command.

[0179] S509, Slip Rate Monitoring and Intervention.

[0180] Specifically, during the operation of the grader, the slip ratio of each wheel can be calculated. For any wheel, if the slip ratio is greater than the preset slip ratio threshold, the engine's target torque is reduced to the safe threshold, and the target speed ratio is increased to the safe speed ratio.

[0181] The grader control method provided in this application is similar in principle and beneficial effect to the technical solution shown in the above embodiments, and will not be repeated here.

[0182] Figure 6 This is a schematic diagram of the structure of the grader control device provided in an embodiment of this application. Please refer to... Figure 6 The grader control device 60 includes:

[0183] The first processing module 61 is used to determine the target driving force required by the grader based on the grader's current operating parameters and the target vehicle speed in the target leveling mode.

[0184] The reverse calculation module 62 is used to reverse calculate the target speed and target torque of the engine based on the target driving force and the current operating parameters;

[0185] The second processing module 63 is used to determine the target speed ratio of the continuously variable transmission based on the target vehicle speed, target rotation speed, and wheel parameters of the grader.

[0186] The control module 64 is used to control the operation of the grader based on the target speed, target torque, and target speed ratio.

[0187] The grader control device provided in this application embodiment can execute the technical solution shown in the above method embodiment. Its implementation principle and beneficial effects are similar, and will not be described again here.

[0188] In one possible implementation, the current operating parameters include the current vehicle speed, vehicle mass, and driving resistance; the first processing module 61 is specifically used for:

[0189] Determine the current acceleration based on the target vehicle speed, the current vehicle speed, and the speed adjustment time;

[0190] The product of the current acceleration and the total vehicle mass is determined as the accelerating traction force;

[0191] The sum of the accelerating traction force and the driving resistance is determined as the target driving force.

[0192] In one possible implementation, the reverse calculation module 62 is specifically used for:

[0193] Based on the target driving force, current vehicle speed, and continuously variable transmission (CVT) efficiency graph, the target input torque of the CVT is calculated in reverse.

[0194] Based on the target input torque, the target engine speed is determined in the universal characteristic curve of the engine, and the fuel consumption rate of the engine at the target speed is less than a preset threshold.

[0195] The target torque of the engine is determined based on the target input torque and the transmission efficiency between the continuously variable transmission (CVT) and the engine.

[0196] In one possible implementation, the reverse calculation module 62 is specifically used for:

[0197] Calculate the target output torque of the continuously variable transmission (CVT) based on the target driving force and the current vehicle speed;

[0198] Based on the target output torque, determine the target operating parameters of the continuously variable transmission (CVT).

[0199] Based on the target operating parameters, the working efficiency of the continuously variable transmission (CVT) is determined in the CVT efficiency map.

[0200] The target input torque of the continuously variable transmission (CVT) is obtained by reverse calculation based on the working efficiency and the target output torque.

[0201] In one possible implementation, the second processing module 63 is specifically used for:

[0202] The product of the target vehicle speed, the wheel rolling radius correction coefficient, and the rear axle speed ratio is determined as the transmission speed ratio correction value.

[0203] The ratio of the transmission speed ratio correction value to the target speed is determined as the target speed ratio.

[0204] In one possible implementation, the control module 64 is specifically used for:

[0205] Send a speed adjustment command to the engine controller so that the engine controller adjusts the current engine speed to the target speed according to the speed adjustment command;

[0206] Send a torque adjustment command to the engine controller so that the engine controller adjusts the engine's current torque to the target torque according to the torque adjustment command;

[0207] Send a speed ratio adjustment command to the actuator of the continuously variable transmission (CVT) so that the actuator adjusts the current speed ratio of the CVT to the target speed ratio according to the speed ratio adjustment command.

[0208] In one possible implementation, the second processing module 63 is also used to calculate the slip ratio of each wheel during the operation of the grader, the slip ratio being used to reflect the degree of wheel slippage.

[0209] The control module 64 is also used to, for any wheel, if the wheel slip ratio is greater than a preset slip ratio threshold, reduce the engine's target torque to a safe threshold and increase the target speed ratio to a safe speed ratio. The safe speed ratio is determined based on the target speed ratio and the difference between the slip ratio and the preset slip ratio threshold.

[0210] The grader control device provided in this application embodiment can execute the technical solution shown in the above method embodiment. Its implementation principle and beneficial effects are similar, and will not be described again here.

[0211] Figure 7 This is a schematic diagram of the controller provided in an embodiment of this application. Please refer to... Figure 7 The controller 70 provided in this embodiment includes at least one processor 71 and a memory 72. Optionally, the controller 70 further includes a communication component 73. The processor 71, memory 72, and communication component 73 are connected via a bus 74.

[0212] In a specific implementation, at least one processor 71 executes computer execution instructions stored in memory 72, causing at least one processor 71 to perform the above-described method.

[0213] The specific implementation process of processor 71 can be found in the above method embodiments, and its implementation principle and technical effect are similar. It will not be repeated here.

[0214] In the above embodiments, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0215] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device.

[0216] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0217] Figure 8 This is a schematic diagram of the structure of the grader provided in an embodiment of this application. Please refer to [link / reference]. Figure 8 The grader 80 includes: an engine 81, an engine controller 82, a continuously variable transmission (CVT) 83, an actuator 84, and a controller 85; wherein the engine 81 is connected to both the CVT 83 and the engine controller 82; the CVT 83 is connected to the actuator 84; and the controller 85 is connected to both the actuator 84 and the engine controller 82. This implements the grader control method shown in the above embodiment.

[0218] In one specific implementation, the continuously variable transmission 83 can replace the mechanical stepped transmission with fixed gear control, preferably a push-block metal belt or a hydraulic pump-motor system; its input end is transmitted to the continuously variable transmission 83 through a coupling / clutch 86, and then drives the wheels through the rear axle 87.

[0219] In an alternative implementation, engine 81 can also be replaced with a high-power drive motor to construct a pure electric or hybrid-driven grader operating system.

[0220] In the structure of the grader 80, the sensor group 88 is the core component for data acquisition. It is connected to the controller 85 and can collect the current operating parameters of the grader in real time. It can include a vehicle speed sensor for collecting the current vehicle speed, a torque sensor for collecting the output torque of the engine 81 and the input / output torque of the continuously variable transmission 83, a slope sensor for collecting the inclination angle of the working road surface, a speed sensor for collecting the real-time speed of the engine 81, and a mass sensor for collecting the load mass of the entire vehicle, etc.

[0221] The human-machine interface 89 interacts bidirectionally with the controller 85, serving as the command exchange medium between the operator and the grader. It can include mode selection, parameter setting, and status display functions. The mode selection function includes options for switching between operating modes such as fine leveling mode, high-efficiency transfer mode, and manual control mode. The parameter setting function allows operators to manually input or adjust core control indicators such as target vehicle speed, fuel consumption rate threshold, and slip rate threshold. The status display function provides real-time, digital, and visual representations of key operating data, including the current and target engine speeds, and the current and target gear ratios of the continuously variable transmission (CVT).

[0222] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0223] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0224] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0225] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0226] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0227] 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 units can be selected to achieve the purpose of this embodiment according to actual needs.

[0228] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0229] If a function is implemented as 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 this invention, 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 of the various embodiments of this 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.

[0230] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0231] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for controlling a grader, characterized in that, The grader includes a continuously variable transmission and an engine, and the method includes: Based on the current operating parameters of the grader and the target vehicle speed in the target leveling mode, determine the target driving force required by the grader; Based on the target driving force and the current operating parameters, the target speed and target torque of the engine are calculated in reverse. The target speed ratio of the continuously variable transmission is determined based on the target vehicle speed, the target rotational speed, and the wheel parameters of the grader. The operation of the grader is controlled based on the target rotational speed, the target torque, and the target speed ratio.

2. The method according to claim 1, characterized in that, The current operating parameters include the current vehicle speed, vehicle weight, and driving resistance; determining the target driving force required by the grader based on the grader's current operating parameters and the target vehicle speed in the target leveling mode includes: The current acceleration is determined based on the target vehicle speed, the current vehicle speed, and the speed adjustment time. The product of the current acceleration and the total vehicle mass is determined as the acceleration traction force; The sum of the accelerating traction force and the driving resistance is determined as the target driving force.

3. The method according to claim 2, characterized in that, The step of calculating the target speed and target torque of the engine in reverse based on the target driving force and the current operating parameters includes: Based on the target driving force, the current vehicle speed, and the continuously variable transmission (CVT) efficiency graph, the target input torque of the CVT is calculated in reverse. Based on the target input torque, the target speed of the engine is determined from the universal characteristic curve of the engine, and the fuel consumption rate of the engine at the target speed is less than a preset threshold. The target torque of the engine is determined based on the target input torque and the transmission efficiency between the continuously variable transmission and the engine.

4. The method according to claim 3, characterized in that, The step of calculating the target input torque of the continuously variable transmission (CVT) in reverse, based on the target driving force, the current vehicle speed, and the CVT efficiency graph, includes: Calculate the target output torque of the continuously variable transmission based on the target driving force and the current vehicle speed; Based on the target output torque, the target operating parameters of the continuously variable transmission are determined; Based on the target operating parameters, the working efficiency of the continuously variable transmission (CVT) is determined in the CVT efficiency map. The target input torque of the continuously variable transmission (CVT) is obtained by performing a reverse calculation based on the working efficiency and the target output torque.

5. The method according to any one of claims 1-4, characterized in that, The wheel parameters include the wheel rolling radius correction coefficient and the rear axle speed ratio; determining the target speed ratio of the continuously variable transmission (CVT) based on the target vehicle speed, the target rotational speed, and the wheel parameters of the grader includes: The product of the target vehicle speed, the wheel rolling radius correction coefficient, and the rear axle speed ratio is determined as the transmission speed ratio correction value. The ratio of the transmission speed ratio correction value to the target speed is determined as the target speed ratio.

6. The method according to any one of claims 1-4, characterized in that, The step of controlling the operation of the grader based on the target rotational speed, the target torque, and the target speed ratio includes: Send a speed adjustment command to the engine controller so that the engine controller adjusts the current speed of the engine to the target speed according to the speed adjustment command; A torque adjustment command is sent to the engine controller so that the engine controller adjusts the current torque of the engine to the target torque according to the torque adjustment command; A speed ratio adjustment command is sent to the actuator of the continuously variable transmission (CVT) so that the actuator adjusts the current speed ratio of the CVT to the target speed ratio according to the speed ratio adjustment command.

7. The method according to any one of claims 1-4, characterized in that, The method further includes: During the operation of the grader, the slip ratio of each wheel is calculated, which reflects the degree of wheel slippage. For any wheel, if the slip ratio of the wheel is greater than a preset slip ratio threshold, the target torque of the engine is reduced to a safe threshold, and the target speed ratio is increased to a safe speed ratio. The safe speed ratio is determined based on the target speed ratio and the difference between the slip ratio and the preset slip ratio threshold.

8. A grader control device, characterized in that, The device includes: The first processing module is used to determine the target driving force required by the grader based on the current operating parameters of the grader and the target vehicle speed in the target leveling mode. The reverse calculation module is used to reverse calculate the target speed and target torque of the engine based on the target driving force and the current operating parameters; The second processing module is used to determine the target speed ratio of the continuously variable transmission based on the target vehicle speed, the target rotational speed, and the wheel parameters of the grader. The control module is used to control the operation of the grader based on the target rotational speed, the target torque, and the target speed ratio.

9. A controller, characterized in that, include: Memory, processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory, causing the processor to perform the method as described in any one of claims 1-7.

10. A grader, characterized in that, include: An engine, an engine controller, a continuously variable transmission, an actuator, and a controller as described in claim 9; The engine is connected to the continuously variable transmission and the engine controller, respectively. The continuously variable transmission is connected to the actuator; The controller is connected to the actuator and the engine controller respectively.

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