Intelligent control system for chassis of high-pass agricultural machine

Abstract

The invention relates to the technical field of agricultural machine chassis control, in particular to an intelligent control system of a high-pass agricultural machine chassis. The system comprises an environment sensing module, an attitude correction module, a stability analysis module, a gravity center compensation module and a risk monitoring module. According to the method, rapid hydraulic leveling is directly carried out according to the real-time vehicle body attitude under the complex flat terrain, and high-precision self-adaptive adjustment is realized by comparing the error between the pre-judged gradient and the actually measured attitude angle under the flat terrain, that is, the leveling precision is still maintained under the interference of terrain abrupt change and the like; according to the pitch angle and the roll angle, hydraulic supporting force distribution and driving torque distribution are dynamically adjusted so as to cope with the longitudinal instability risk during climbing / downhill; and meanwhile, the change rate of the roll angle is monitored in real time, a safety mode of maximum flow output of the hydraulic system is triggered immediately when a sharp instability trend is detected, emergency posture recovery is achieved, and the operation stability, safety and accuracy of the agricultural machinery in the hilly and mountainous regions under complex working conditions are improved.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery chassis control technology, and in particular to an intelligent control system for high-speed agricultural machinery chassis. Background Technology

[0002] Currently, agricultural machinery operating in complex terrains such as hills and mountains generally faces technical bottlenecks such as poor chassis passability and insufficient operational stability. Traditional agricultural machinery chassis lack the ability to perceive and adaptively adjust to terrain undulations and slope changes in real time. Due to the complex terrain, steep slopes, and fragmented plots, agricultural machinery chassis rollover accidents are frequent. Continuous steep slopes and multi-directional slopes cause dynamic shifts in the chassis center of gravity, significantly increasing the risk of chassis tilting and seriously threatening operational safety. At the same time, due to the failure to achieve coordination between forward-looking terrain prediction and real-time attitude control, the leveling system of agricultural machinery suffers from problems such as response lag and insufficient precision, which not only affects the quality of agronomic practices such as tillage and sowing but also restricts the development level of agricultural mechanization in hilly and mountainous areas.

[0003] Chinese Patent Publication No. CN108454345A discloses a method for adjusting the body of agricultural machinery, including: collecting the posture information of the agricultural machinery; calculating a solenoid valve control signal based on the posture information; and controlling the solenoid valve to perform opening or closing actions based on the solenoid valve control signal, so as to control the posture adjustment hydraulic cylinder to move or not move to keep the rear chassis in a level state. It can be seen that existing intelligent control technologies for agricultural machinery chassis, when facing the common terrain changes in hilly and mountainous areas, rely solely on real-time posture prediction of the vehicle's current position for delayed adjustment. When the ground suddenly undulates irregularly... The actual tilt of the vehicle body has already occurred and exceeded the threshold. Only then does the hydraulic system start leveling, resulting in a slow adjustment action. At the same time, the control model based on fixed parameters is difficult to cope with the nonlinear response caused by sudden changes in soil pressure. For example, when one side of the track suddenly sinks, the traditional PID control cannot predict the transient changes in load and will produce overshoot oscillation, further amplifying the attitude fluctuation. This leveling error accumulated due to response delay and control mismatch ultimately causes the chassis platform to be unable to maintain a stable horizontal reference during continuous operation, resulting in uneven tillage depth and deviation of the sowing trajectory, thereby reducing the quality and efficiency of precision agriculture operations. Summary of the Invention

[0004] Therefore, the present invention provides an intelligent control system for high-pass agricultural machinery chassis to overcome the problem in the prior art that the chassis leveling error is large due to interference such as sudden changes in terrain, which leads to low leveling accuracy.

[0005] To achieve the above objectives, the present invention provides an intelligent control system for high-speed agricultural machinery chassis, comprising: The environmental perception module is used to determine the current terrain environment based on the slope and undulation of the area to be worked on, including the first terrain environment and the second terrain environment; The attitude correction module, which is connected to the environmental perception module, is used to respond to the second terrain environment. When the agricultural machinery to be monitored actually enters the work area, it determines whether to execute the hydraulic leveling command based on the error comparison between the real-time attitude angle and the predicted slope. The stability analysis module, which is connected to the environment perception module and the attitude correction module respectively, is used to respond to the comparison results of the first terrain environment and the second error, analyze the longitudinal slope based on the real-time pitch angle to obtain the longitudinal slope analysis result, and analyze the lateral slope based on the real-time roll angle to obtain the lateral slope analysis result. A center of gravity compensation module, which is connected to the stability analysis module, is used to adjust the distribution of the shaft hydraulic support force according to the load displacement in response to the second longitudinal slope analysis results. A risk monitoring module, connected to the stability analysis module, is used to predict the overturning risk of the monitored agricultural machinery based on the real-time roll angle change rate in response to the second lateral slope analysis results.

[0006] Furthermore, the environmental perception module includes an analysis unit and a classification unit; The analysis unit is used to determine the unevenness coefficient based on the point cloud distribution map and to determine the real-time slope change rate based on the slope distribution map. The classification unit is used to classify the current terrain environment into a first terrain environment or a second terrain environment based on the unevenness coefficient and the real-time slope change rate.

[0007] Furthermore, the analysis unit includes a scanning subunit, a first calculation subunit, and a second calculation subunit; The scanning subunit is used to scan the area to be worked on using lidar to obtain a point cloud distribution map and a slope distribution map. The first calculation subunit is used to calculate the standard deviation of the elevation values ​​corresponding to each point cloud on the point cloud distribution map, and obtain the unevenness coefficient; The second calculation subunit calculates the standard deviation of the real-time slope change on the slope distribution map to obtain the real-time slope change rate.

[0008] Furthermore, when the unevenness coefficient is greater than the first coefficient threshold and the slope change rate is greater than the first change rate threshold, the classification unit determines the current terrain environment as the first terrain environment; Otherwise, the current terrain environment is determined to be the second terrain environment.

[0009] Furthermore, the attitude correction module includes a slope prediction calculation unit, a real-time attitude monitoring unit, and an error analysis unit; The predicted slope calculation unit is used to determine the predicted slope based on the real-time driving direction and slope distribution map of the agricultural machinery to be monitored, and to calculate the expected vehicle posture based on the predicted slope. The predicted slope includes the predicted longitudinal slope and the predicted lateral slope. The real-time attitude monitoring unit is used to obtain the real-time attitude angle of the agricultural machinery under monitoring at a preset sampling frequency when the agricultural machinery under monitoring actually enters the work area, and to calculate the actual error between the predicted slope and the real-time attitude angle. The error analysis unit is used to compare the actual error with the allowable error to obtain the error comparison result. In response to the second error comparison result, it executes the hydraulic leveling command according to the real-time attitude angle.

[0010] Furthermore, the predicted slope calculation unit includes a slope component calculation subunit and a vehicle posture prediction subunit; The slope component calculation subunit is used to determine the slope component based on a rectangular coordinate system established according to the real-time driving direction of the agricultural machinery to be monitored, and to determine the predicted longitudinal slope and the predicted lateral slope based on the slope component. The vehicle attitude prediction subunit is used to calculate the expected vehicle attitude based on the predicted longitudinal slope and the predicted lateral slope.

[0011] Furthermore, the stability analysis module includes a longitudinal slope analysis unit and a transverse slope analysis unit; The longitudinal slope analysis unit is used to obtain the real-time pitch angle, and compares the absolute value of the real-time pitch angle with a first preset threshold to obtain the first longitudinal slope analysis result or the second longitudinal slope analysis result. The lateral slope analysis unit is used to obtain the real-time roll angle in response to the absolute value of the real-time pitch angle being less than or equal to a first preset threshold. The absolute value of the real-time roll angle is then compared with a second preset threshold to obtain a first lateral slope analysis result or a second lateral slope analysis result.

[0012] Furthermore, the center of gravity compensation module includes a load monitoring unit and a response adjustment unit; The load monitoring unit is used to obtain the real-time load displacement and compare the real-time load displacement with the standard load displacement. The response adjustment unit adjusts the hydraulic cylinder support force according to the direction of the center of gravity offset when the real-time load displacement is greater than the standard load displacement, and adjusts the drive torque according to the slippage monitoring result when the real-time load displacement is less than or equal to the standard load displacement.

[0013] Furthermore, the response adjustment unit includes a support force distribution adjustment subunit and a torque distribution subunit; The support force distribution adjustment subunit is used to analyze the direction of the center of gravity offset based on the positive or negative value of the real-time load displacement, so as to adjust the distribution of the hydraulic cylinder support force. The torque distribution subunit is used to distribute torque in response to a comparison between the rotational speed of each drive wheel and the actual travel speed of the agricultural machinery.

[0014] Furthermore, the risk monitoring module includes a roll angle monitoring unit and a roll angle analysis unit; The roll angle monitoring unit is used to calculate the roll angle change rate in response to the second lateral slope analysis results; The roll angle analysis unit is used to compare the roll angle change rate with a risk threshold: If the rate of change of the roll angle exceeds the risk threshold, the hydraulic system is controlled to output at maximum flow to perform emergency attitude recovery. If the rate of change of the roll angle is less than or equal to the risk threshold, then determine whether to fine-tune the deviation based on the deviation between the actual displacement and the target displacement of each hydraulic cylinder, so as to adjust the actual displacement of the hydraulic cylinder to the target displacement.

[0015] Compared with existing technologies, the advantages of this invention are that it identifies the degree of terrain undulation in real time through an environmental perception module, classifying it into a rugged first terrain environment or a relatively flat second terrain environment. In complex flat terrain, it directly performs rapid hydraulic leveling based on the real-time vehicle posture. In flat terrain, it achieves high-precision adaptive adjustment by comparing the error between the predicted slope and the measured posture angle, thus ensuring that leveling accuracy is maintained even under disturbances such as sudden terrain changes. The system integrates stability analysis and center of gravity compensation mechanisms, dynamically adjusting the distribution of hydraulic support force and drive torque according to pitch and roll angles to cope with the risk of longitudinal instability when climbing / descending. At the same time, by monitoring the roll angle change rate in real time, it immediately triggers the safety mode of maximum flow output of the hydraulic system when a sharp instability trend is detected, achieving emergency posture recovery. Through multi-module collaborative closed-loop control, it improves the operational stability, safety, and accuracy of agricultural machinery in hilly and mountainous areas under complex working conditions, effectively suppresses the risk of rollover, and ensures the quality of fine agricultural techniques such as tillage and sowing. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the intelligent control system of the agricultural machinery chassis according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the environmental perception module in an embodiment of the present invention; Figure 3 This is a schematic diagram of the attitude correction module according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the risk monitoring module in an embodiment of the present invention. Detailed Implementation

[0017] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0018] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0019] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0020] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] Please see Figure 1 As shown, this is a schematic diagram of the structure of the intelligent control system for a high-pass agricultural machinery chassis according to an embodiment of the present invention. The present invention provides an intelligent control system for a high-pass agricultural machinery chassis, comprising: The environmental perception module is used to determine the current terrain environment based on the slope and undulation of the area to be worked on, including the first terrain environment and the second terrain environment; The attitude correction module, which is connected to the environmental perception module, is used to respond to the second terrain environment. When the agricultural machinery to be monitored actually enters the work area, it determines whether to execute the hydraulic leveling command based on the error comparison between the real-time attitude angle and the predicted slope. The stability analysis module, which is connected to the environment perception module and the attitude correction module respectively, is used to respond to the comparison results of the first terrain environment and the second error, analyze the longitudinal slope based on the real-time pitch angle to obtain the longitudinal slope analysis result, and analyze the lateral slope based on the real-time roll angle to obtain the lateral slope analysis result. A center of gravity compensation module, which is connected to the stability analysis module, is used to adjust the distribution of the shaft hydraulic support force according to the load displacement in response to the second longitudinal slope analysis results. A risk monitoring module, connected to the stability analysis module, is used to predict the overturning risk of the monitored agricultural machinery based on the real-time roll angle change rate in response to the second lateral slope analysis results.

[0022] The system uses an environmental perception module to identify the degree of terrain undulation in real time, classifying it into a rugged first terrain environment or a relatively flat second terrain environment. In complex flat terrain, it performs rapid hydraulic leveling directly based on the real-time vehicle posture. In flat terrain, it achieves high-precision adaptive adjustment by comparing the error between the predicted slope and the measured posture angle, ensuring that leveling accuracy is maintained even under disturbances such as sudden terrain changes. The system integrates stability analysis and center of gravity compensation mechanisms, dynamically adjusting the distribution of hydraulic support force and drive torque according to pitch and roll angles to cope with the risk of longitudinal instability when climbing / descending. At the same time, by monitoring the roll angle change rate in real time, it immediately triggers the safety mode of maximum hydraulic system flow output when a sharp instability trend is detected, achieving emergency posture recovery. Through multi-module collaborative closed-loop control, the system improves the operational stability, safety, and accuracy of agricultural machinery in hilly and mountainous areas under complex working conditions, effectively suppressing the risk of rollover and ensuring the quality of fine agricultural techniques such as tillage and sowing.

[0023] See Figure 2 As shown, it is a structural schematic diagram of the environmental perception module in an embodiment of the present invention; Specifically, the environmental perception module includes an analysis unit and a classification unit; The analysis unit is used to determine the unevenness coefficient based on the point cloud distribution map and to determine the real-time slope change rate based on the slope distribution map. The classification unit is used to classify the current terrain environment into a first terrain environment or a second terrain environment based on the unevenness coefficient and the real-time slope change rate.

[0024] In this embodiment, the first terrain environment indicates that the surface of the work area has deep furrows and scattered gravel, while the second terrain environment indicates that the surface of the work area is relatively flat, allowing agricultural machinery to travel relatively smoothly. In the first terrain environment, there is no need to verify the predicted error; the hydraulic leveling command is directly calculated based on the actual attitude angle fed back in real time. Simultaneously, during the operation, stability analysis and overturning risk analysis are performed on the monitored agricultural machinery to determine the stability of the chassis and ensure operational safety. In the second terrain environment, the real-time attitude angle of the agricultural machinery as it enters the work area is compared with the expected attitude angle to analyze whether unpredictable situations such as sudden terrain changes or ground subsidence have caused a large error. Then, the hydraulic leveling command is recalculated based on the actual attitude angle fed back in real time, overriding the previous predicted command, so that the system can still maintain high-precision leveling capability and ensure the operational safety of the agricultural machinery.

[0025] Specifically, the analysis unit includes a scanning subunit, a first calculation subunit, and a second calculation subunit; The scanning subunit is used to scan the area to be worked on using lidar to obtain a point cloud distribution map and a slope distribution map. The first calculation subunit is used to calculate the standard deviation of the elevation values ​​corresponding to each point cloud on the point cloud distribution map, and obtain the unevenness coefficient; The second calculation subunit calculates the standard deviation of the real-time slope change on the slope distribution map to obtain the real-time slope change rate.

[0026] In this embodiment, the point cloud within the LiDAR scanning area is projected onto a two-dimensional plane to obtain a point cloud distribution map. The process of obtaining the slope begins with the processing and analysis of three-dimensional spatial data. Point cloud data of the area to be worked on is collected using equipment such as LiDAR. This point cloud data contains the three-dimensional coordinates (X, Y, Z) of a large number of surface points. After data preprocessing, vegetation, buildings, and other non-ground points are removed, leaving a clean ground point cloud. Then, spatial interpolation algorithms, such as Kriging or inverse distance weighting, are used to convert these discrete ground point clouds into a regular raster digital elevation model, where the value of each raster cell represents the elevation at that location. Based on this, the slope is then... Slope calculation tools, such as the slope tool in ArcGIS or corresponding algorithms, are used to analyze the raster digital elevation model. The slope calculation tool uses a 3x3 moving window to traverse each cell in the raster digital elevation model, calculating the rate of elevation change between the central cell and its eight neighboring cells in the east-west direction (dZ / dX) and the north-south direction (dZ / dY) to characterize the slope of the ground surface at that point. Finally, based on the rate of change in these two directions, the slope value of each cell is calculated using the slope calculation formula, expressed in degrees or percentages. The slope values ​​of all cells constitute a complete slope distribution map. The slope calculation formula is as follows: Slope = The unit is percentage.

[0027] Specifically, when the unevenness coefficient is greater than the first coefficient threshold and the slope change rate is greater than the first change rate threshold, the classification unit determines the current terrain environment as the first terrain environment. Otherwise, the current terrain environment is determined to be the second terrain environment.

[0028] In this embodiment, a point cloud distribution map is obtained by scanning the area to be worked with a lidar. Calculate the standard deviation of the elevation values ​​corresponding to each point cloud on the point cloud distribution map to obtain the unevenness coefficient; Compare the unevenness coefficient with the first coefficient threshold: If the unevenness coefficient is greater than the first coefficient threshold, the current terrain environment is determined based on the comparison between the real-time slope change rate and the first change rate threshold. If the unevenness coefficient is less than or equal to the first coefficient threshold, the current terrain environment is determined to be the second terrain environment; The current terrain environment is determined based on the comparison between the real-time slope change rate and the first change rate threshold: Obtain the slope distribution map and the slope of each pixel, calculate the slope change between adjacent pixels, and obtain the real-time slope change. Calculate the standard deviation of the real-time slope change in the entire work area based on the slope distribution map to obtain the real-time slope change rate; Compare the real-time slope change rate with the first change rate threshold: If the real-time slope change rate is less than or equal to the first change rate threshold, the current terrain environment is determined to be the second terrain environment. If the real-time slope change rate is greater than the first change rate threshold, the current terrain environment is determined to be the first terrain environment. In this embodiment, the first coefficient threshold is used to determine the flatness of the ground surface, representing the tolerable height difference of ground undulations. Exceeding this threshold indicates that the ground itself is uneven, which will produce continuous bumps and vibrations, potentially affecting the normal driving and operational stability of agricultural machinery. In this case, it is necessary to analyze the current terrain environment in conjunction with the degree of slope change. The first coefficient threshold is set to 0.1 meters. The first rate of change threshold is used to determine the degree of slope change, initially characterizing the abrupt change of the terrain and measuring whether there are terrain features such as steep slopes, field ridges, and ditches that cause the slope to change drastically over a short distance. The first rate of change threshold represents the speed of terrain change that the system control response can keep up with. Exceeding this threshold indicates that the terrain changes too quickly, and the predictive control system may fail due to response delay. In this case, the current terrain environment is determined to be the first terrain environment. The first rate of change threshold is set to 5° / meter.

[0029] See Figure 3 As shown, it is a structural schematic diagram of the attitude correction module in an embodiment of the present invention; Specifically, the attitude correction module includes a slope prediction calculation unit, a real-time attitude monitoring unit, and an error analysis unit; The predicted slope calculation unit is used to determine the predicted slope based on the real-time driving direction and slope distribution map of the agricultural machinery to be monitored, and to calculate the expected vehicle posture based on the predicted slope. The predicted slope includes the predicted longitudinal slope and the predicted lateral slope. The real-time attitude monitoring unit is used to obtain the real-time attitude angle of the agricultural machinery under monitoring at a preset sampling frequency when the agricultural machinery under monitoring actually enters the work area, and to calculate the actual error between the predicted slope and the real-time attitude angle. The error analysis unit is used to compare the actual error with the allowable error to obtain the error comparison result. In response to the second error comparison result, it executes the hydraulic leveling command according to the real-time attitude angle. The error comparison results include the first error comparison result and the second error comparison result. The first error comparison result indicates that the pitch angle prediction is reliable and the roll angle prediction is reliable. The second error comparison result indicates that either the pitch angle prediction or the roll angle prediction is unreliable.

[0030] In this embodiment, the allowable error is a threshold for determining the accuracy of the prediction. Since the lidar is mounted on the front of the agricultural machinery, it scans the terrain several meters to tens of meters in front of the machinery, providing a predicted slope along the path. The vehicle attitude sensor, on the other hand, measures the real-time attitude directly beneath the machinery's chassis, providing the slope at the current location. In scenarios involving fragmented and rugged hilly terrain, if the terrain changes drastically between the predicted point and the actual location the vehicle travels to—for example, a gentle slope might be predicted, but a small pothole or bump is encountered upon actual driving—an error will occur. If the error is poor, the predicted slope is verified by comparing it with the actual attitude angle of the vehicle body in real time. If the error is within an acceptable range, no readjustment is needed. If the error is too large, the hydraulic leveling command needs to be recalculated based on the actual attitude angle in real time, overriding the previous predicted command. This ensures that the control system can still maintain high-precision leveling capability under unpredictable interferences such as sudden terrain changes and ground subsidence, thus ensuring operational safety. The first and second allowable errors are set within the range of 2°-3°. Preferably, the first allowable error is set to 2° and the second allowable error is set to 2.5°.

[0031] In this embodiment, when the agricultural machinery actually enters the area, the measured real-time attitude angle is compared with the expected attitude angle. That is, the first actual error between the expected pitch angle and the real-time pitch angle is calculated, and the second actual error between the expected roll angle and the real-time roll angle is calculated. The first actual error is then compared with the first allowable error. If the first actual error is less than or equal to the first permissible error, the roll angle prediction is considered reliable. If the first actual error is greater than the first permissible error, the roll angle prediction is deemed unreliable. Compare the second actual error with the second permissible error: If the second actual error is less than or equal to the second allowable error, the pitch angle prediction is deemed reliable. If the second actual error is greater than the second allowable error, the pitch angle prediction is deemed unreliable. When the pitch angle prediction is deemed unreliable or the roll angle prediction is deemed unreliable, the hydraulic cylinder compensation amount corresponding to the four support points in the vehicle body coordinate system is calculated based on the real-time attitude angle, and a hydraulic leveling command is issued based on the hydraulic cylinder compensation amount. In this embodiment, the process of calculating the hydraulic cylinder compensation amount corresponding to the four support points in the vehicle coordinate system based on the real-time attitude angle is as follows: The vehicle coordinate system is established with the geometric center of the chassis leveling platform as the origin. The X-axis is longitudinal, pointing in the direction of vehicle movement, the Y-axis is lateral, pointing to the right side of the vehicle, and the Z-axis is vertically upward along the origin. The four support points are located at the left front, right front, left rear, and right rear of the origin, respectively. The distances from the origin are: half the wheelbase in the X direction and half the track width in the Y direction. The compensation amount of the hydraulic cylinders corresponding to the four support points is obtained through the displacement calculation formula.

[0032] The displacement calculation formula is Δh = L × sin(θ) × signXi + W × sin(φ) × signYi; Where: Δh is the hydraulic cylinder compensation amount corresponding to the i-th hydraulic cylinder, which represents the displacement that needs to be extended or retracted, in meters. Δh > 0 indicates that the hydraulic cylinder needs to be extended, and Δh < 0 indicates that it needs to be retracted. L is half of the chassis wheelbase, in meters; W is half of the chassis track, in meters; θ is the measured real-time pitch angle, in degrees or radians, with the front of the vehicle pointing upwards being positive; φ is the measured real-time roll angle, in degrees or radians, with a positive rightward tilt. signXi and signYi are sign coefficients, which are determined by the position of support point i. The specific values ​​are shown in Table 1. Table 1. Values ​​of the sign coefficient ; The left front is located in the second quadrant, which is the left side of the front of the agricultural machinery; the right front is located in the third quadrant, which is the right side of the front of the agricultural machinery; the left rear is located in the first quadrant, which is the left side of the rear of the agricultural machinery; and the right rear is located in the fourth quadrant, which is the right side of the rear of the agricultural machinery. For example, if the chassis parameters of the agricultural machinery to be monitored are L=1.0 m and W=0.8 m, the real-time pitch angle θ is 3°≈0.0524 radians, and the real-time roll angle φ is -4°≈-0.0698 radians; the attitude of the agricultural machinery is that the front of the vehicle is tilted upwards and the left side is raised. By calculating the compensation amount for each hydraulic cylinder: For the left front hydraulic cylinder: Δh = -1.0 × sin(3°) + 0.8 × sin(-4°) ≈ -1.0 × 0.05236 + 0.8 × (-0.0697) ≈ -0.05236 - 0.05581 = -0.1082 meters; For the right front hydraulic cylinder: Δh = -1.0 × sin(3°) - 0.8 × sin(-4°) ≈ -0.05236 - 0.8 × (-0.06976) ≈ -0.05236 + 0.05581 = +0.0035 meters; For the left rear hydraulic cylinder: Δh = -1.0 × sin(3°) + 0.8 × sin(-4°) ≈ 1.0 × 0.05236 + 0.8 × (-0.0697) ≈ 0.05236 - 0.05581 = -0.0035 meters; For the right rear hydraulic cylinder: Δh = 1.0 × sin(3°) - 0.8 × sin(-4°) ≈ 1.0 × 0.05236 - 0.8 × (-0.0697) ≈ 0.05236 + 0.05581 = +0.1082 meters; Therefore, the output commands are: the left front cylinder needs to contract by 108.2 mm, the right front cylinder needs to extend slightly by 3.5 mm (almost remaining stationary), the left rear cylinder needs to contract slightly by 3.5 mm (almost remaining stationary), and the right rear cylinder needs to extend by 108.2 mm.

[0033] When the first actual error is determined to be greater than the first permissible error, or the second actual error is greater than the second permissible error, it indicates that the error is large due to ground subsidence, sudden terrain changes, etc., indicating that the prediction is unreliable. In this case, the hydraulic leveling command is recalculated based on the real-time attitude angle to ensure vehicle safety and constitute the system's dynamic error suppression capability, ensuring that the leveling accuracy is maintained under interference such as sudden terrain changes.

[0034] Specifically, the predicted slope calculation unit includes a slope component calculation subunit and a vehicle posture prediction subunit; The slope component calculation subunit is used to determine the slope component based on a rectangular coordinate system established according to the real-time driving direction of the agricultural machinery to be monitored, and to determine the predicted longitudinal slope and the predicted lateral slope based on the slope component. The vehicle attitude prediction subunit is used to calculate the expected vehicle attitude based on the predicted longitudinal slope and the predicted lateral slope.

[0035] In this embodiment, a rectangular coordinate system is established based on the real-time driving direction of the agricultural machinery to be monitored. The X-axis is the vertical axis, parallel to the longitudinal axis of the agricultural machinery and pointing in the direction of its forward movement; the Y-axis is the horizontal axis, perpendicular to the longitudinal axis of the agricultural machinery and pointing to the right side of the agricultural machinery. Simultaneously with generating the slope distribution map, a slope aspect distribution map is also generated. Each pixel on the slope aspect distribution map corresponds to a unique slope aspect value, representing the direction of the steepest slope at that point. The slope aspect value corresponding to any pixel defines the direction the slope faces, i.e., the projection direction of the normal to the downhill direction onto the horizontal plane. Measurements are taken clockwise from 0° north, with a range of... It is between 0° and 360°; the slope is decomposed into longitudinal and transverse directions through vector projection. The longitudinal slope component along the X-axis of the agricultural machinery to be monitored is calculated based on the slope aspect: longitudinal slope component = slope × cosβ, and the transverse slope component along the Y-axis of the agricultural machinery to be monitored is calculated based on the slope aspect: longitudinal slope component = slope × sinβ, where β is the angle between the slope aspect and the direction of travel of the agricultural machinery to be monitored; the average longitudinal slope of the area is calculated based on the longitudinal slope component to obtain the predicted longitudinal slope; the average transverse slope of the area is calculated based on the transverse slope component to obtain the predicted transverse slope; the expected pitch angle and expected roll angle are calculated based on the predicted longitudinal slope and predicted transverse slope.

[0036] The expected vehicle attitude is calculated based on the predicted longitudinal and lateral slopes. The expected vehicle attitude includes the expected pitch angle and the expected roll angle. The formula for calculating the expected pitch angle is: Expected Pitch Angle = Predicted Longitudinal Slope × cosγ, where γ is the angle between the agricultural machinery's travel direction and the main slope direction. The formula for calculating the expected roll angle is: Expected Roll Angle = Predicted Lateral Slope + Predicted Longitudinal Slope × (sinγ) × (H / B) × C, where H is the center of gravity height of the agricultural machinery to be monitored, B is the track center distance, and C... For example, if the predicted lateral slope is 5°, the predicted longitudinal slope is 10°, γ is 30°, H is 1.2m, and B is 1.5m, then the predicted pitch angle = 10°×cos30°≈10°×0.866≈8.66°; the predicted roll angle = 5°+(10°×sin(30°)×(1.2 / 1.5)×1.1)=5°+(10°×0.5×0.8×1.1)=5×4.4°=9.4°.

[0037] Specifically, the stability analysis module includes a longitudinal slope analysis unit and a transverse slope analysis unit; The longitudinal slope analysis unit is used to obtain the real-time pitch angle, and compares the absolute value of the real-time pitch angle with a first preset threshold to obtain the first longitudinal slope analysis result or the second longitudinal slope analysis result. The lateral slope analysis unit is used to obtain the real-time roll angle in response to the absolute value of the real-time pitch angle being less than or equal to a first preset threshold. The absolute value of the real-time roll angle is then compared with a second preset threshold to obtain a first lateral slope analysis result or a second lateral slope analysis result.

[0038] In this embodiment, the absolute value of the real-time pitch angle is compared with a first preset threshold: If the absolute value of the real-time pitch angle is greater than the first preset threshold, the first longitudinal slope analysis result is obtained, and the center of gravity compensation module executes the longitudinal center of gravity compensation strategy to adjust the hydraulic cylinder support force or adjust the drive torque. If the absolute value of the real-time pitch angle is less than or equal to the first preset threshold, the second longitudinal slope analysis result is obtained; The absolute value of the real-time roll angle is compared with the second preset threshold: If the absolute value of the real-time roll angle is greater than or equal to the second preset threshold, the first lateral slope analysis result is obtained. Based on the current roll angle, the compensation amount of the hydraulic cylinder is recalculated to generate the optimal leveling command and drive the hydraulic cylinder to move. If the absolute value of the real-time roll angle is less than the second preset threshold, the second lateral slope analysis result is obtained. In this embodiment, the pitch and roll angles of the vehicle body are directly measured by a vehicle body attitude sensor installed on the chassis of the agricultural machinery to be monitored. These angles reflect the actual tilt angle of the agricultural machinery chassis relative to the horizontal reference plane. The first preset threshold is a safety limit for the longitudinal tilt angle, which is set to 10°. When the absolute value of the vehicle body pitch angle exceeds the first preset threshold, it indicates that the longitudinal stability is affected, which may cause the front or rear of the vehicle to lift up, posing a potential risk of overturning backward or forward. It is necessary to perform longitudinal compensation of the center of gravity in time by adjusting the support force ratio of the front and rear hydraulic cylinders to counteract the center of gravity shift caused by gravity, which is equivalent to pushing or pulling the center of gravity back to a safer position. The second preset threshold is a safety limit for the lateral tilt angle. When the vehicle's roll angle, i.e., the absolute value of the angle at which the vehicle tilts to the left or right, exceeds the lateral roll angle, it indicates an increased risk of rollover. Since rollover is a more sudden and dangerous process than longitudinal instability, the lower tolerance for rollover risk and higher safety requirements necessitate setting the second preset threshold to be smaller than the first preset threshold. The second preset threshold is set to 8°. When the roll angle reaches 8°, the vertical projection line of the agricultural machinery's center of gravity has shifted significantly towards the edge of the support wheel, leaving very little stability margin. Any further tilt or disturbance could quickly lead to instability. Therefore, the optimal leveling command is immediately calculated, driving the hydraulic cylinders to forcibly and quickly right the tilted vehicle, achieving the most direct and effective center of gravity adjustment. To immediately interrupt the current task, the compensation amount of the hydraulic cylinder is recalculated based on the current roll angle, and active hydraulic leveling is performed until the roll angle returns to a safe range and stabilizes. Only then is the highest priority released, and the current task resumed. For example, if a farm machine is fertilizing on a slope, and the system is simultaneously performing tasks such as maintaining vehicle speed and precisely controlling the amount of fertilizer applied, and suddenly detects that the right wheel has sunk, and the roll angle quickly reaches 9° and continues to increase, the fine-tuning of the fertilizer application will be immediately interrupted. The optimal leveling command will be calculated, and the hydraulic system will be instructed to significantly extend the left hydraulic cylinder and retract the right hydraulic cylinder within a fraction of a second to forcibly straighten the vehicle. Only when the roll angle returns to a safe range and stabilizes will the highest priority be released, and the system will resume precise control of the fertilization operation.

[0039] Specifically, the center of gravity compensation module includes a load monitoring unit and a response adjustment unit; The load monitoring unit is used to obtain the real-time load displacement and compare the real-time load displacement with the standard load displacement. The response adjustment unit adjusts the hydraulic cylinder support force according to the direction of the center of gravity offset when the real-time load displacement is greater than the standard load displacement, and adjusts the drive torque according to the slippage monitoring result when the real-time load displacement is less than or equal to the standard load displacement.

[0040] In this embodiment, the standard load displacement is set to ±50 mm. Weighing sensors installed on the front and rear axles are used to acquire the weight borne by the front and rear axles in real time. Based on the weight data of the front and rear axles, the fore-and-aft position of the entire agricultural machinery's center of gravity is calculated to determine the fore-and-aft offset distance of the center of gravity relative to the chassis center point, thus obtaining the real-time load displacement. This real-time load displacement is compared with the standard load displacement: if the real-time load displacement is greater than the standard load displacement, the hydraulic cylinder support force is adjusted according to the sign of the real-time load displacement; if the real-time load displacement is less than or equal to the standard load displacement... The system sequentially compares the rotational speed of each drive wheel with the actual speed of the agricultural machinery. If the rotational speed of a drive wheel is greater than the actual speed, it determines that the corresponding wheel is slipping. The system then adjusts the drive torque according to the wheel type: if the front wheel slips, the drive torque transmitted to the front axle is reduced, and more torque is distributed to the rear axle with better traction; if the rear wheel slips, the drive torque transmitted to the rear axle is reduced, and more torque is distributed to the front axle. This ensures that power is always preferentially delivered to the wheels that are not slipping and have good traction, thereby effectively suppressing slippage and ensuring that the agricultural machinery obtains continuous and efficient traction while saving fuel.

[0041] In this embodiment, the process of adjusting the hydraulic cylinder support force according to the direction of the center of gravity offset is as follows: the direction of the center of gravity offset is analyzed based on the positive or negative sign of the real-time load displacement. If the real-time load displacement is positive, reduce the support force of the front axle hydraulic cylinder and increase the support force of the rear axle hydraulic cylinder, that is, adjust the front axle support force from 60% to 40%-50% and the rear axle support force from 40% to 50%-60%; If the real-time load displacement is negative, increase the support force of the front axle hydraulic cylinder and decrease the support force of the rear axle hydraulic cylinder. That is, adjust the front axle support force from 40% to 50%-60% and the rear axle support force from 60% to 40%-50%.

[0042] When the real-time load displacement is greater than the standard load displacement, it indicates a large displacement, meaning a severe shift in the center of gravity. Dynamic adjustment of the hydraulic support forces on the front and rear axles is necessary. The direction of the center of gravity shift is analyzed based on the sign of the real-time load displacement. If the real-time load displacement is positive, it indicates a severe rearward shift in the center of gravity. In this case, while climbing a slope, there is a risk of the front of the vehicle lifting up. Adjusting the distribution of the hydraulic cylinder support forces creates a torque to resist the front lifting, pulling the center of gravity forward and stabilizing the vehicle. If the real-time load displacement is negative, it indicates a severe forward shift in the center of gravity. In this case, while descending a slope, there is a risk of the rear lifting up. Adjusting the distribution of the hydraulic cylinder support forces resists the rear lifting, pulling the center of gravity backward to prevent the front or rear from lifting up due to excessive center of gravity shift, ensuring driving stability.

[0043] Specifically, the response adjustment unit includes a support force distribution adjustment subunit and a torque distribution subunit; The support force distribution adjustment subunit is used to analyze the direction of the center of gravity offset based on the positive or negative value of the real-time load displacement, so as to adjust the distribution of the hydraulic cylinder support force. The torque distribution subunit is used to distribute torque in response to a comparison between the rotational speed of each drive wheel and the actual travel speed of the agricultural machinery.

[0044] See Figure 4 As shown, it is a structural schematic diagram of the risk monitoring module in an embodiment of the present invention; Specifically, the risk monitoring module includes a roll angle monitoring unit and a roll angle analysis unit; The roll angle monitoring unit is used to calculate the roll angle change rate in response to the second lateral slope analysis results; The roll angle analysis unit is used to compare the roll angle change rate with a risk threshold: If the rate of change of the roll angle exceeds the risk threshold, the hydraulic system is controlled to output at maximum flow to perform emergency attitude recovery. If the rate of change of the roll angle is less than or equal to the risk threshold, then determine whether to fine-tune the deviation based on the deviation between the actual displacement and the target displacement of each hydraulic cylinder, so as to adjust the actual displacement of the hydraulic cylinder to the target displacement.

[0045] In this embodiment, controlling the hydraulic system to output maximum flow includes maximizing pump displacement from start-up, fully opening the proportional valve, and emergency release of the accumulator. Specifically, the controller sends a maximum displacement signal to the variable pump servo mechanism, instantly increasing the pump displacement from the normal operating 15-25 cm³ / rev to 45 cm³ / rev, while simultaneously increasing the engine speed to the rated speed of 2200 rpm, thus maximizing pump displacement from start-up. The process of fully opening the proportional valve involves increasing the proportional valve control current from the normal operating 200-600 mA to a maximum of 800 mA, fully opening the valve core, maximizing the flow area, and increasing the system flow rate from the normal 40 L / min to 100 L / min. The emergency release of the accumulator involves opening the accumulator. A quick-release valve between the actuator and the accumulator instantly releases the 30MPa high-pressure oil pre-charged in the accumulator, providing an additional 20L of instantaneous flow replenishment. Emergency posture recovery is achieved by extending or retracting the hydraulic cylinder at maximum speed. The process of determining whether to fine-tune the deviation based on the actual displacement and target displacement of each hydraulic cylinder is as follows: Real-time readings of the displacement sensor values ​​of the four hydraulic cylinders are used to calculate the deviation between the actual displacement and target displacement of each hydraulic cylinder. If the deviation is within ±1mm, the current state is maintained; if the deviation exceeds ±1mm, fine-tuning is performed. The target displacement is the compensation amount for the hydraulic cylinder. The fine-tuning process involves calculating the adjustment speed as the PID output based on the proportional coefficient, integral coefficient, and derivative coefficient, and comparing the adjusted speed with the maximum adjustment speed. If the adjustment speed is less than the maximum adjustment speed, the adjustment speed is used as the actual execution speed. If the adjustment speed is greater than or equal to the maximum adjustment speed, the maximum adjustment speed is used as the actual execution speed. The hydraulic cylinder is controlled to slowly correct according to the actual execution speed until it enters the dead zone range of ±0.1mm, at which point active adjustment stops and only monitoring is performed. The proportional coefficient Kp=0.3, the integral coefficient Ki=0.05, the derivative coefficient Kd=0.02, the maximum adjustment speed=2.0mm / s, and the control cycle=0.05 seconds. For example, if the current displacement=98.5mm and the target displacement=100.0mm, then the displacement error=target displacement-current displacement=100.0-98.5=1.5mm, and the proportional term P=Kp×error=0.3×1.5=0. 45. Integral term I = Ki × error × time = 0.05 × 1.5 × 0.05 = 0.00375, Differential term D = Kd × (current error - previous error) / time = 0.02 × (1.5 - 1.5) / 0.05 = 0, PID output = P + I + D = 0.45 + 0.00375 + 0 = 0.45375 mm / s, Calculated adjustment speed 0.45375 mm / s < maximum speed 2.0 mm / s, Actual execution speed = 0.45375 mm / s, Distance moved in 0.05 seconds = speed × time = 0.45375 × 0.05 = 0.0227 mm, New current position = 98.5 + 0.0227 = 98.5227 mm, New error = 100.0 - 98.5227 = 1.4773 mm. Therefore, the second PID calculation is performed at time 0.10. The proportional term P = 0.3 × 1.4773 = 0.4432, the integral term I = 0.00375 + (0.05 × 1.4773 × 0.05) = 0.00375 + 0.003693 = 0.007443, and the differential term D = 0.02 × (1.4773 - 1.5) / 0.05 = 0. 0.02 × (-0.0227) / 0.05 = -0.00908, PID output = 0.4432 + 0.007443 - 0.00908 = 0.4416 mm / s. The system continues to slowly correct at a rate of approximately 0.44 mm / s. After about 3.4 seconds, the displacement reaches 99.99 mm, with an error of only 0.01 mm. At this point, the system enters the dead zone (±0.1 mm), stops active adjustment, and only performs monitoring.

[0046] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A high-throughput intelligent control system for agricultural machinery chassis, characterized in that, include: The environmental perception module is used to determine the current terrain environment based on the slope and undulation of the area to be worked on, including the first terrain environment and the second terrain environment; The attitude correction module, which is connected to the environmental perception module, is used to respond to the second terrain environment. When the agricultural machinery to be monitored actually enters the work area, it determines whether to execute the hydraulic leveling command based on the error comparison between the real-time attitude angle and the predicted slope. The stability analysis module, which is connected to the environment perception module and the attitude correction module respectively, is used to respond to the comparison results of the first terrain environment and the second error, analyze the longitudinal slope based on the real-time pitch angle to obtain the longitudinal slope analysis result, and analyze the lateral slope based on the real-time roll angle to obtain the lateral slope analysis result. A center of gravity compensation module, which is connected to the stability analysis module, is used to adjust the distribution of the shaft hydraulic support force according to the load displacement in response to the second longitudinal slope analysis results. The risk monitoring module, which is connected to the stability analysis module, is used to predict the overturning risk of the agricultural machinery under monitoring based on the real-time roll angle change rate in response to the second lateral slope analysis results.

2. The intelligent control system for high-pass agricultural machinery chassis according to claim 1, characterized in that, The environmental perception module includes an analysis unit and a classification unit; The analysis unit is used to determine the unevenness coefficient based on the point cloud distribution map and to determine the real-time slope change rate based on the slope distribution map. The classification unit is used to classify the current terrain environment into a first terrain environment or a second terrain environment based on the unevenness coefficient and the real-time slope change rate.

3. The intelligent control system for high-pass agricultural machinery chassis according to claim 2, characterized in that, The analysis unit includes a scanning subunit, a first calculation subunit, and a second calculation subunit; The scanning subunit is used to scan the area to be worked on using lidar to obtain a point cloud distribution map and a slope distribution map. The first calculation subunit is used to calculate the standard deviation of the elevation values ​​corresponding to each point cloud on the point cloud distribution map to obtain the unevenness coefficient; The second calculation subunit calculates the standard deviation of the real-time slope change on the slope distribution map to obtain the real-time slope change rate.

4. The intelligent control system for high-pass agricultural machinery chassis according to claim 2, characterized in that, When the unevenness coefficient is greater than the first coefficient threshold and the slope change rate is greater than the first change rate threshold, the classification unit determines the current terrain environment as the first terrain environment. Otherwise, the current terrain environment is determined to be the second terrain environment.

5. The intelligent control system for high-pass agricultural machinery chassis according to claim 1, characterized in that, The attitude correction module includes a slope prediction calculation unit, a real-time attitude monitoring unit, and an error analysis unit. The predicted slope calculation unit is used to determine the predicted slope based on the real-time driving direction and slope distribution map of the agricultural machinery to be monitored, and to calculate the expected vehicle posture based on the predicted slope. The predicted slope includes the predicted longitudinal slope and the predicted lateral slope. The real-time attitude monitoring unit is used to obtain the real-time attitude angle of the agricultural machinery under monitoring at a preset sampling frequency when the agricultural machinery under monitoring actually enters the work area, and to calculate the actual error between the predicted slope and the real-time attitude angle. The error analysis unit is used to compare the actual error with the allowable error to obtain the error comparison result. In response to the second error comparison result, it executes the hydraulic leveling command according to the real-time attitude angle.

6. The intelligent control system for high-pass agricultural machinery chassis according to claim 5, characterized in that, The predicted slope calculation unit includes a slope component calculation subunit and a vehicle attitude prediction subunit; The slope component calculation subunit is used to determine the slope component based on a rectangular coordinate system established according to the real-time driving direction of the agricultural machinery to be monitored, and to determine the predicted longitudinal slope and the predicted lateral slope based on the slope component. The vehicle attitude prediction subunit is used to calculate the expected vehicle attitude based on the predicted longitudinal slope and the predicted lateral slope.

7. The intelligent control system for high-pass agricultural machinery chassis according to claim 1, characterized in that, The stability analysis module includes a longitudinal slope analysis unit and a transverse slope analysis unit; The longitudinal slope analysis unit is used to obtain the real-time pitch angle, and compares the absolute value of the real-time pitch angle with a first preset threshold to obtain the first longitudinal slope analysis result or the second longitudinal slope analysis result. The lateral slope analysis unit is used to obtain the real-time roll angle in response to the absolute value of the real-time pitch angle being less than or equal to a first preset threshold. The absolute value of the real-time roll angle is then compared with a second preset threshold to obtain a first lateral slope analysis result or a second lateral slope analysis result.

8. The intelligent control system for high-pass agricultural machinery chassis according to claim 1, characterized in that, The center of gravity compensation module includes a load monitoring unit and a response adjustment unit; The load monitoring unit is used to obtain the real-time load displacement and compare the real-time load displacement with the standard load displacement. The response adjustment unit adjusts the hydraulic cylinder support force according to the direction of the center of gravity offset when the real-time load displacement is greater than the standard load displacement, and adjusts the drive torque according to the slippage monitoring result when the real-time load displacement is less than or equal to the standard load displacement.

9. The intelligent control system for high-pass agricultural machinery chassis according to claim 8, characterized in that, The response adjustment unit includes a support force distribution adjustment subunit and a torque distribution subunit; The support force distribution adjustment subunit is used to analyze the direction of the center of gravity offset based on the positive or negative value of the real-time load displacement, so as to adjust the distribution of the hydraulic cylinder support force. The torque distribution subunit is used to distribute torque in response to a comparison between the rotational speed of each drive wheel and the actual travel speed of the agricultural machinery.

10. The intelligent control system for high-pass agricultural machinery chassis according to claim 1, characterized in that, The risk monitoring module includes a roll angle monitoring unit and a roll angle analysis unit; The roll angle monitoring unit is used to calculate the roll angle change rate in response to the second lateral slope analysis results; The roll angle analysis unit is used to compare the roll angle change rate with a risk threshold: If the rate of change of the roll angle exceeds the risk threshold, the hydraulic system is controlled to output at maximum flow to perform emergency attitude recovery. If the rate of change of the roll angle is less than or equal to the risk threshold, then determine whether to fine-tune the deviation based on the deviation between the actual displacement and the target displacement of each hydraulic cylinder, so as to adjust the actual displacement of the hydraulic cylinder to the target displacement.

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