A field path automatic deviation correction optimization method for a laser navigation-based cantaloupe transplanting machine

Abstract

The present application relates to the technical field of deviation correction optimization, in particular to a kind of field path automatic deviation correction optimization method of melon transplanting machine based on laser navigation, including by laser receiver array, real-time capture reference laser signal projected by laser plane transmitter;According to the distribution of the irradiation position of reference laser signal in receiver array, the real-time pitch angle and roll angle of transplanting machine are solved;Based on real-time pitch angle and roll angle, generate calibration laser plane equation;Synchronous output transverse position deviation and heading angle deviation;According to the coupling relationship of transverse position deviation and heading angle deviation, generate steering motor control amount and travel speed compensation amount by section;The steering motor control amount and travel speed compensation amount are synchronously output to the steering servo system and walking hydraulic system of transplanting machine, realize continuous deviation correction between ridge.The present application can real-time perceive the pitch angle and roll angle of transplanting machine in the process of running in field by constructing laser receiver array and attitude solution model.

Description

Technical Field

[0001] This invention relates to the field of deviation correction and optimization technology, and in particular to an automatic deviation correction and optimization method for field paths of watermelon and melon transplanting machinery based on laser navigation. Background Technology

[0002] In modern facility agriculture and precision planting systems, high-value-added crops such as watermelons and melons place higher demands on transplanting precision. Especially in ridge planting environments, machinery must move precisely along a preset path; otherwise, planting position deviation, uneven hole spacing, or seedling damage can easily occur, affecting yield and marketability. Currently, some transplanting equipment relies on simple mechanical guidance structures or manual visual assistance to adjust direction. When faced with complex field terrain (such as undulating ridges, slight slopes, and sunken areas) and operational disturbances (such as slippage and signal blockage), path tracking stability is poor and response is lagging, failing to meet the needs of high-precision automated transplanting. At the same time, existing control systems mostly adopt open-loop control logic, lacking attitude perception and real-time feedback, which can easily lead to correction failure or over-steering, affecting operational efficiency and machinery stability.

[0003] To address the aforementioned issues, laser navigation-based automatic path correction methods are gradually emerging in the agricultural machinery field, offering advantages such as non-contact operation, anti-interference capabilities, and high precision. However, existing laser navigation devices are mostly concentrated in straight-line driving or indoor positioning applications, and an integrated control scheme adapting to transplanting operations—combining "attitude calculation—path deviation extraction—control quantity generation—servo closed-loop execution"—has not yet been formed. In actual farmland environments, there is a mechanical installation angle between the laser receiver and the chassis; if not corrected, this will lead to the accumulation of attitude perception errors. Furthermore, there is a significant coupling characteristic between lateral position deviation and heading angle deviation, requiring joint modeling and control. However, existing methods lack refined parameter partitioning and dynamic compensation mechanisms. Therefore, there is an urgent need for an automatic path correction method for watermelon and melon transplanting machinery that is oriented towards ridge cultivation environments, possesses high robustness and closed-loop execution capabilities, and can improve operational continuity and planting accuracy. Summary of the Invention

[0004] To achieve the above objectives, this invention provides an automatic path correction and optimization method for watermelon and melon transplanting machinery based on laser navigation.

[0005] A laser-guided automatic path correction and optimization method for watermelon and melon transplanting machinery includes the following steps:

[0006] S1: The reference laser signal projected by the laser planar emitter is captured in real time by a laser receiver array installed on top of the transplanting machine;

[0007] S2: Based on the distribution of the reference laser signal at the illumination position of the receiver array, calculate the real-time pitch and tilt angles of the transplanting equipment;

[0008] S3: Based on real-time pitch and tilt angles, the mechanical installation deviation between the laser emitter and the transplanter chassis is eliminated through spatial coordinate transformation to generate a calibration laser plane equation;

[0009] S4: Compare the calibration laser plane equation with the spatial equation of the preset reference path, and output the lateral position deviation and heading angle deviation simultaneously;

[0010] S5: Based on the coupling relationship between lateral position deviation and heading angle deviation, generate steering motor control quantity and travel speed compensation quantity in segments.

[0011] S6: Synchronously outputs the steering motor control quantity and the travel speed compensation quantity to the steering servo system and travel hydraulic system of the transplanting machine to achieve continuous deviation correction between rows.

[0012] Furthermore, S1 includes:

[0013] S11: Laser receiver units are evenly distributed on the top of the transplanting machine to collect the intensity of the laser signal received by each receiver in real time and form a time-series signal vector;

[0014] S12: Identify the receiver unit with the strongest signal and determine the illumination position of the laser beam on the receiver array based on its preset coordinates.

[0015] Furthermore, S12 includes:

[0016] S121: Perform maximum value normalization on the time-series signal vector to identify the peak region of laser irradiation;

[0017] S122: Based on the identification receiver number and the preset receiver array coordinates, obtain the irradiation position coordinates of the reference laser on the array.

[0018] Furthermore, S2 includes:

[0019] S21: Select multiple receiver units that have received strong laser signals, and fit the spatial plane of the current laser irradiation area by least squares method according to their spatial positions in the machine coordinate system.

[0020] S22: Based on the normal vector direction of the fitted plane, calculate the tilt angle of the plane relative to the machine body in the front-back direction and the tilt angle in the left-right direction, respectively, as the real-time estimation result of the current machine posture.

[0021] Furthermore, S21 includes:

[0022] S211: Select several receiver units with significant laser signal response intensity from the laser receiver array and extract their three-dimensional spatial coordinates in the body coordinate system of the transplanting machine;

[0023] S212: Based on the extracted three-dimensional spatial coordinates of the receiver, the least squares fitting method is used to construct the equation of the laser irradiation plane.

[0024] Furthermore, S22 includes:

[0025] S221: Construct the normal vector of the laser irradiation plane based on its equation;

[0026] S222: Calculate the pitch angle and tilt angle of the transplanting machine using the slope coefficient of the laser-irradiated plane.

[0027] Furthermore, S3 includes:

[0028] S31: Based on the calculated pitch and tilt angles, construct a three-dimensional rotation matrix representing the attitude of the laser receiver array;

[0029] S32: Transform the original normal vector of the laser irradiation plane to the chassis coordinate system to obtain the calibration normal vector. Substitute the calibrated normal vector into the standard plane equation form to construct the calibration laser plane equation.

[0030] Furthermore, S4 includes:

[0031] S41: Set the expression of the preset reference path in three-dimensional space as a spatial straight line, project the normal vector in the current calibration laser plane equation onto the reference path, and calculate the shortest distance from the center point of the laser plane to the reference path as the lateral position deviation.

[0032] S42: Project the normal vector of the calibration laser plane onto the horizontal direction to construct a projection vector representing the current heading trend; compare the angle with the reference path direction vector to obtain the heading angle deviation of the current transplanting equipment.

[0033] Furthermore, S5 includes:

[0034] S51: After normalizing the lateral position deviation and heading angle deviation, a weighted coupled deviation function is constructed.

[0035] S52: Based on the segment where the coupling deviation function is located, use a segmented control strategy to generate the steering motor control quantity and the travel speed compensation quantity respectively.

[0036] Furthermore, S6 includes:

[0037] S61: Convert the calculated steering motor control quantity and travel speed compensation quantity into the standard signal format required by the hardware control interface;

[0038] S62: The control angle command and control speed value are synchronously output to the steering servo controller and the walking hydraulic drive unit to control the direction and speed of the implement in real time, realize continuous correction between rows, and the feedback sensor monitors the changes in the attitude of the implement in real time to form a closed-loop control.

[0039] The beneficial effects of this invention are:

[0040] This invention constructs a laser receiver array and attitude calculation model to perceive the pitch and roll angles of transplanting machinery in real time during field operation. It also introduces a spatial coordinate transformation algorithm to eliminate the mechanical installation deviation between the laser transmitter and the chassis, generating a calibrated laser plane equation and improving the accuracy of attitude estimation. Furthermore, by comparing with a preset benchmark path in space, it accurately extracts the lateral position deviation and heading angle deviation, and constructs a deviation coupling function. Based on this, it dynamically generates steering motor control and travel speed compensation quantities, realizing zoned response and multi-parameter control of path deviation.

[0041] This invention employs a servo-hydraulic combined closed-loop control mechanism. Compared to traditional manual alignment or simplified control strategies, it automatically corrects execution results based on feedback signals, enabling real-time and adaptive steering and speed adjustments, significantly improving system stability and anti-interference capabilities. This method is particularly suitable for transplanting crops such as ridge cultivation and watermelons and melons, which are sensitive to the precision of planting holes. It can effectively reduce planting errors and replanting rates, improve overall operation quality and efficiency, and promote the development of high-value-added crop planting operations towards intelligence and precision. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a flowchart of a method according to an embodiment of the present invention;

[0044] Figure 2 This is a cross-row correction diagram according to an embodiment of the present invention. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0046] like Figures 1-2 As shown, a laser-guided automatic path correction and optimization method for watermelon and melon transplanting machinery includes the following steps:

[0047] S1: The reference laser signal projected by the laser planar emitter is captured in real time by a laser receiver array installed on top of the transplanting machine;

[0048] S1 specifically includes:

[0049] S11: N laser receiver units are evenly distributed on the top of the transplanting machine to collect the laser signal intensity received by each receiver in real time. And form a time-series signal vector, represented as:

[0050] ;

[0051] in, is the intensity of the laser signal received by the i-th receiver at time t, with a value ranging from 0 to 10000. Laser emitters generally use adjustable beam intensity, and when they illuminate the receiver array, they often exhibit an illuminance level of several hundred to several thousand lux in actual working environments. The high dynamic range design supports stable signal acquisition in strong sunlight or low light environments. N is the total number of receiver units, with a value ranging from 4 to 16, used to balance angular resolution and system cost. A smaller number (4 units) can provide basic directional resolution and is suitable for low-cost devices; increasing the number of receivers (16 units) can improve angular accuracy and anti-interference capability. Considering the overall system complexity and resolution requirements, the value is 4 to 16.

[0052] S12: Identify the receiver unit with the strongest signal and determine the illumination position of the laser beam on the receiver array based on its preset coordinates, for subsequent attitude calculation and path deviation analysis.

[0053] S12 specifically includes:

[0054] S121: For time-series signal vectors After performing maximum value normalization, the peak region of laser irradiation is identified, and the corresponding receiver unit index is represented as follows:

[0055] ;

[0056] in, Let be the index of the receiver unit that receives the strongest laser signal at time t, with a value range of . The main laser irradiation point is selected from the receiver numbers by searching for the maximum value. Since it directly reflects the current laser beam landing point, it must be in the existing set of numbers, and the value range corresponds to the total number of receivers.

[0057] S122: Based on the identification receiver number Combined with preset receiver array coordinates The coordinates of the reference laser's illumination position on the array are obtained, and are represented as follows:

[0058] ;

[0059] in, The spatial position of the i-th receiver in the coordinate system of the machine body is: The three-dimensional location within the range is designed to meet compact deployment requirements. The spatial position of the laser beam illuminating the receiver array at time t is used as the input for attitude calculation, and its value ranges from [value missing]. This is equivalent to the physical boundary of the receiver deployment area.

[0060] S2: Based on the distribution of the reference laser signal at the illumination position of the receiver array, calculate the real-time pitch and tilt angles of the transplanting equipment;

[0061] S2 specifically includes:

[0062] S21: Select multiple receiver units that receive strong laser signals, and fit the spatial plane of the current laser irradiation area by least squares method according to their spatial position in the machine coordinate system, so as to reflect the tilting trend of the laser beam on the array.

[0063] S21 specifically includes:

[0064] S211: Select several receiver units with significant laser signal response intensity from the laser receiver array, and extract their three-dimensional spatial coordinates in the coordinate system of the transplanting machine. ;

[0065] S212: Based on the extracted three-dimensional spatial coordinates of the receiver, the least squares fitting method is used to construct the equation of the laser illumination plane, which is expressed as:

[0066] ;

[0067] in, It is the spatial position of the i-th receiver unit in the coordinate system of the transplanting machine. , The receiver array is typically mounted on a flat structure atop the transplanting machinery, with a length and width not exceeding 1 meter and a height between 1 and 1.5 meters above the ground to avoid crop obstruction and ensure laser visibility. A and B are the slope coefficients of the laser illumination plane, reflecting the degree of inclination in the x and y directions. The machine's attitude angle generally does not tilt drastically. The range covers typical working conditions, and C is the plane intercept term. Since the receiver array is installed on top of the machine at a fixed height of 1-1.5 meters, the fitting plane naturally falls within this range. The intercept term is only used as an auxiliary parameter and is not directly used for attitude calculation.

[0068] S22: Based on the normal vector direction of the fitted plane, calculate the tilt angle (pitch angle) of the plane relative to the machine body in the front-back direction and the tilt angle (tilt angle) in the left-right direction, respectively, as the real-time estimation result of the current machine attitude.

[0069] S22 specifically includes:

[0070] S221: According to the equation of the laser irradiation plane Construct its normal vector, which is represented as:

[0071] ;

[0072] Where n is the unit normal vector of the laser irradiation plane, which describes the spatial orientation of the laser irradiation plane relative to the coordinate system of the machine body and is used for subsequent attitude angle calculation;

[0073] S222: Using the slope coefficients A and B of the laser-irradiated plane, calculate the pitch and tilt angles of the transplanting machinery, respectively, as follows:

[0074] ;

[0075] ;

[0076] Among them, pitch angle Indicates the degree of tilt of the machine in the forward and backward direction. Exceeding this limit may affect the quality and stability of the operation; tilt angle Indicates the degree of tilt in the left and right directions. When moving between the rows of plants, the machinery often tilts slightly to the left or right. To prevent the tracks from slipping or the planting holes from shifting, the tilt angle is controlled at [value missing]. It is advisable to keep the internal parameters within a certain range to ensure steady-state operation.

[0077] S3: Based on real-time pitch and tilt angles, the mechanical installation deviation between the laser emitter and the transplanter chassis is eliminated through spatial coordinate transformation to generate a calibration laser plane equation;

[0078] S3 specifically includes:

[0079] S31: Pitch angle based on the solution with roll angle Construct a three-dimensional rotation matrix representing the orientation of the laser receiver array, denoted as:

[0080] ;

[0081] in, This is a three-dimensional rotation matrix representing the attitude of the laser receiver array. This matrix is ​​used to transform the normal vector of the laser irradiation plane from the receiver array coordinate system to the transplanter chassis reference system. The value range of each element is... The rotation matrix is ​​composed of sine and cosine functions, and its range is limited to ±1. It is used to maintain geometric orthogonality and length invariance when performing rigid body posture transformation.

[0082] S32: The original normal vector of the laser-irradiated plane. Transform to the chassis coordinate system to obtain the calibration normal vector, and then use the calibrated normal vector... Substituting into the standard plane equation form, we construct the calibration laser plane equation, which is expressed as:

[0083] ;

[0084] ;

[0085] in, The calibration laser plane normal vector obtained after attitude transformation is defined in the machine chassis coordinate system, and the value range of each component is as follows: Ultimately, the normal vector after orientation rotation reflects the actual orientation of the laser plane in three-dimensional space, effectively avoiding deviations introduced by installation errors. It is to calibrate the laser plane normal vector. The three components correspond to respectively Direction, range of values ​​is The direction vector is used to construct the plane equation, and each component should be consistent with the sine / cosine of the triaxial angle, with a maximum amplitude of 1. D is a constant term in the calibration laser plane equation, used to determine the absolute position of the plane in space, and its value range is... It is determined by the dot product of the normal vector and the coordinates of the array center point, and its value varies with the installation height and orientation. It can cover the height of most agricultural machinery structures.

[0086] S4: Compare the calibration laser plane equation with the spatial equation of the preset reference path, and output the lateral position deviation and heading angle deviation simultaneously;

[0087] S4 specifically includes:

[0088] S41: Set the preset reference path to a straight line in three-dimensional space, project the normal vector in the current calibration laser plane equation onto the reference path, and calculate the center point of the laser plane. The shortest distance to the reference path is taken as the lateral position deviation, and expressed as follows:

[0089] ;

[0090] ;

[0091] in, It is a preset reference path expressed as a spatial straight line in three-dimensional space. It is the lateral positional deviation, indicating the calibration laser reference point. The shortest distance to the reference path, with values ​​ranging from 1 to 2. Considering that the row spacing and the width of the agricultural machinery are usually 0.6-1.2, the navigation deviation control target is generally no more than 0.5 to ensure the quality requirements of precise navigation and fixed-point transplanting. This is the vector modulus operator, used to calculate the Euclidean length of a vector. Its value depends on the size of the input vector and is a non-negative real number, ensuring geometric consistency in error measurement. These are the reference path start coordinates, the initial point position used for spatial path representation. The reference path is laid out from the plot boundary. The path start coordinates are not fixed, but are usually within the known grid coordinate system range of the entire work area, supporting continuous path modeling. d is the reference path direction vector, describing the spatial direction of the path. The vector magnitude is 1, and the values ​​of each component range from... Paths are typically constructed using straight line segments as basic units. Their direction can be derived from the coordinates of the start and end points, and after normalization, they are used for projection and angle calculations to ensure consistent result scale. 's' is a path parameter representing the positional scalar of points on the path, with a value range of [value missing]. L is the total path length, used to generate the coordinate vector of any point on the path, supporting continuous path function representation and spatial analysis. It is the reference point for calibrating the laser plane in the machine coordinate system, usually taken as the center point of the laser receiver array or the weighted center point. , The receiving array is installed on top of the transplanter, with a planar dimension not exceeding 1 meter, and the horizontal coordinate of its center point is usually located at... The range, and the installation height are usually [missing information]. Meters, to avoid interference from plants and ensure unobstructed laser reception;

[0092] S42: To estimate the degree of deviation in the direction of travel of the transplanting equipment, the normal vector of the calibration laser plane will be... Projecting along the horizontal direction, we construct a projection vector representing the current heading trend. Let the projection direction of the laser plane onto the xy plane be represented as:

[0093] ;

[0094] in, The projection vector of the laser plane normal vector onto the horizontal plane (xy plane) represents the horizontal projection of the current machine's forward direction, and its component values ​​range from [value range missing]. The normalized global direction vector has a magnitude of 1 and is used to estimate the heading direction. It is constructed by rotating about the z-axis. The normal horizontal projection reflects the movement trend of the machinery and is suitable for angle analysis with the path direction.

[0095] With reference path direction vector Compare the included angles to obtain the heading angle deviation of the current transplanting equipment. , is represented as:

[0096] ;

[0097] in, This is the heading angle deviation, representing the horizontal angle between the laser plane direction and the reference path direction, with a value range of... Agricultural operations require high precision in heading control; excessive deviation angles can lead to transplant misalignment, inter-row collisions, or path deviations. Within this range, navigation effectiveness can be ensured. It is the projection of the laser plane normal vector onto the horizontal direction, used to approximate the heading. It is the direction vector of the reference path in the horizontal plane, and the unit direction vector of the reference path in the horizontal plane (xy plane). It represents the horizontal direction of the ideal path, and the component values ​​range from... The module length is 1, which is used to describe the path direction in a two-dimensional plane, so as to facilitate the calculation of the angle between the module and the actual machine direction projection and to evaluate the yaw error.

[0098] S5: Based on the coupling relationship between lateral position deviation and heading angle deviation, generate steering motor control quantity and travel speed compensation quantity in segments.

[0099] S5 specifically includes:

[0100] S51: Adjust lateral position deviation deviation from heading angle After normalization, the weighted coupling bias function is constructed, expressed as:

[0101] ;

[0102] Where E is the coupling deviation function value, used to uniformly characterize the degree of deviation of the current path, with a value range of 0-2. It unifies the deviations of different dimensions through normalization, and the maximum value is the normalized weighted sum of the two deviations, which is used for subsequent segmented control logic judgment. These are the deviation weighting coefficients, corresponding to the weights of the lateral position deviation and heading angle deviation in the coupled error function, respectively, with values ​​ranging from 0 to 1, satisfying... This is used for trade-off configurations in controller design; if path alignment is emphasized more, It can be set to a larger value if more emphasis is placed on directional control. This can improve the ability to quickly eliminate heading deviations. These are the maximum allowable thresholds for lateral deviation and heading angle deviation, respectively, used to normalize the lateral error component. This is the maximum permissible lateral position deviation of the system, ranging from 0.3 to 0.5 meters. Agricultural machinery inter-row navigation typically requires a maximum lateral error of less than 0.5 meters; exceeding this will cause inter-row offset or collision. This is the maximum allowable heading angle deviation of the system, with a value range of 10-15. Navigation systems are quite sensitive to heading angle errors, and it is usually set to no more than ±15° to prevent planting hole deviation or repeated planting.

[0103] S52: Based on the segment where the coupling deviation function E is located, use a segmented control strategy to generate the steering motor control quantity separately. Compensation amount with travel speed , is represented as:

[0104] ;

[0105] in, These are steering motor control commands used to adjust the direction of travel; the value range is... Depending on the steering motor settings, effective correction can typically be achieved within a steering angle range of ±30°. This is a speed control variable used to compensate for speed adjustments caused by lateral deviation, thereby improving stability. Its value range is... When the deviation is large, reduce the speed to avoid drastic deviation; when the deviation is close to zero, approach the rated speed to ensure work efficiency. It is the heading angle control gain, used to adjust the response strength of heading deviation to steering control inputs, and is usually set to... Too little gain will result in sluggish steering response, while too much gain will easily cause oscillations. This is the nominal forward speed, i.e., the normal operating speed under no-deviation conditions, with a value range of 0.3-0.6. The transplanting operation speed needs to balance work quality and efficiency. It is the speed compensation coefficient, which controls the degree to which the offset suppresses the speed; its value range is... A larger value indicates a more sensitive response to offset and can be used in scenarios where accuracy is of paramount importance; if both efficiency and tolerance need to be considered, it is recommended to set it to 0.5.

[0106] S6: Synchronously outputs the steering motor control quantity and the travel speed compensation quantity to the steering servo system and travel hydraulic system of the transplanting machine to achieve continuous deviation correction between rows.

[0107] S6 specifically includes:

[0108] S61: Calculate the steering motor control quantity and travel speed compensation amount Converted to the standard signal format required by the hardware control interface, and mapped as follows:

[0109] ;

[0110] ;

[0111] in, It is a control angle command output to the steering servo motor, used to adjust the forward direction of the machine, with a value range of [value missing]. Depending on the wheel structure and hydraulic steering design, control commands must be limited to its capability boundaries. This refers to the maximum operable steering angle of the steering servo system, ranging from 20° to 35°. The steering angle tolerance of agricultural machinery platforms is limited by the operating radius and mechanical structure. 20° is suitable for straight-line compensation operations, while 35° can support small-range sharp turns. The appropriate upper limit should be selected according to the application scenario. This is the angle compression gain coefficient, which controls the response intensity of input error to the servo steering angle. It is used to buffer high-speed deviation response and has a value range of 0.5~1.5. It is used to suppress steering overshoot or oscillation under high error conditions. When the terrain is uneven or the attitude fluctuates frequently, a smaller value should be selected. A value of 1.0 or higher can improve stability; if rapid correction is required, a value of 1.0 or higher can be selected. This is the control speed value output to the hydraulic travel system, used to adjust the forward speed of the implement; its value range is... For safety and operational accuracy reasons, limiting the maximum speed helps prevent rapid deviation or equipment instability. This is the maximum permissible travel speed of the hydraulic system, ranging from 0.5 to 1.0. Excessive speed may affect the accuracy of transplanting, especially under conditions of automatic walking between rows, to ensure that the error is controlled within a reasonable range.

[0112] S62: Control angle command With control speed value The synchronous output is sent to the steering servo controller and the travel hydraulic drive unit to control the direction and speed of the implement in real time, achieving continuous cross-row correction. Feedback sensors monitor the changes in the implement's attitude in real time, forming a closed-loop control, as shown below:

[0113] ;

[0114] ;

[0115] in, The actual steering angle is measured in real time by an angle sensor, and its value range is... This is used for closed-loop comparison with the control angle. If the difference exceeds the standard, the control command needs to be updated to improve accuracy and responsiveness. The actual travel speed is obtained through a speed sensor or hydraulic flow detector, and its value range is [value missing]. This is used to detect whether the hydraulic system's response matches the set speed value. Excessive discrepancies may indicate system depressurization, abnormal load, or drive lag.

[0116] The aforementioned feedback loop ensures the stability and accuracy of command execution, adapts to different terrains and real-time disturbances, and achieves robust correction control. In complex field terrain and under dynamic disturbance conditions, transplanting machinery is highly susceptible to interference from nonlinear factors such as steering lag, speed fluctuations, and attitude changes during path correction, causing preset control commands to fail to fully reflect the actual operating state. Therefore, a closed-loop control mechanism for the steering motor and walking hydraulic system is introduced. This mechanism can monitor the current execution results of the machinery in real time and compare them with the control target. By dynamically correcting the steering control and speed compensation quantities, it effectively suppresses the accumulation of path tracking errors. The role of this mechanism is to improve the stability and accuracy of the control process, making the system robust and adaptable to typical field conditions such as different soil hardness, ridge undulations, and laser signal disturbances. Ultimately, it achieves steady-state operation and precise correction of the machinery during continuous operation, significantly improving transplanting quality and automation levels.

[0117] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

Claims

1. A method for automatic path correction and optimization of watermelon and melon transplanting machinery based on laser navigation, characterized in that, Includes the following steps: S1: The reference laser signal projected by the laser planar emitter is captured in real time by a laser receiver array installed on top of the transplanting machine; S2: Based on the distribution of the reference laser signal at the illumination position of the receiver array, calculate the real-time pitch and tilt angles of the transplanting equipment; S3: Based on real-time pitch and tilt angles, the mechanical installation deviation between the laser emitter and the transplanter chassis is eliminated through spatial coordinate transformation to generate a calibration laser plane equation; S4: Compare the calibration laser plane equation with the spatial equation of the preset reference path, and output the lateral position deviation and heading angle deviation simultaneously; S5: Based on the coupling relationship between lateral position deviation and heading angle deviation, generate steering motor control quantity and travel speed compensation quantity in segments. S6: Synchronously outputs the steering motor control quantity and the travel speed compensation quantity to the steering servo system and travel hydraulic system of the transplanting machine to achieve continuous deviation correction between rows.

2. The method for automatic correction and optimization of field paths for watermelon and melon transplanting machinery based on laser navigation according to claim 1, characterized in that, S1 includes: S11: Laser receiver units are evenly distributed on the top of the transplanting machine to collect the intensity of the laser signal received by each receiver in real time and form a time-series signal vector; S12: Identify the receiver unit with the strongest signal and determine the illumination position of the laser beam on the receiver array based on its preset coordinates.

3. The method for automatic correction and optimization of field paths for watermelon and melon transplanting machinery based on laser navigation according to claim 2, characterized in that, S12 includes: S121: Perform maximum value normalization on the time-series signal vector to identify the peak region of laser irradiation; S122: Based on the identification receiver number and the preset receiver array coordinates, obtain the irradiation position coordinates of the reference laser on the array.

4. The method for automatic correction and optimization of field paths for watermelon and melon transplanting machinery based on laser navigation according to claim 3, characterized in that, S2 includes: S21: Select multiple receiver units that have received strong laser signals, and fit the spatial plane of the current laser irradiation area by least squares method according to their spatial positions in the machine coordinate system. S22: Based on the normal vector direction of the fitted plane, calculate the tilt angle of the plane relative to the machine body in the front-back direction and the tilt angle in the left-right direction, respectively, as the real-time estimation result of the current machine posture.

5. The method for automatic correction and optimization of field paths for watermelon and melon transplanting machinery based on laser navigation according to claim 4, characterized in that, S21 includes: S211: Select several receiver units with significant laser signal response intensity from the laser receiver array and extract their three-dimensional spatial coordinates in the body coordinate system of the transplanting machine; S212: Based on the extracted three-dimensional spatial coordinates of the receiver, the least squares fitting method is used to construct the equation of the laser irradiation plane.

6. The method for automatic correction and optimization of field paths for watermelon and melon transplanting machinery based on laser navigation according to claim 4, characterized in that, S22 includes: S221: Construct the normal vector of the laser irradiation plane based on its equation; S222: Calculate the pitch angle and tilt angle of the transplanting machine using the slope coefficient of the laser-irradiated plane.

7. The method for automatic correction and optimization of field paths for watermelon and melon transplanting machinery based on laser navigation according to claim 6, characterized in that, S3 includes: S31: Based on the calculated pitch and tilt angles, construct a three-dimensional rotation matrix representing the attitude of the laser receiver array; S32: Transform the original normal vector of the laser irradiation plane to the chassis coordinate system to obtain the calibration normal vector. Substitute the calibrated normal vector into the standard plane equation form to construct the calibration laser plane equation.

8. The method for automatic correction and optimization of field paths for watermelon and melon transplanting machinery based on laser navigation according to claim 7, characterized in that, S4 includes: S41: Set the expression of the preset reference path in three-dimensional space as a spatial straight line, project the normal vector in the current calibration laser plane equation onto the reference path, and calculate the shortest distance from the center point of the laser plane to the reference path as the lateral position deviation. S42: Project the normal vector of the calibration laser plane onto the horizontal direction to construct a projection vector representing the current heading trend; compare the angle with the reference path direction vector to obtain the heading angle deviation of the current transplanting equipment.

9. The method for automatic correction and optimization of field paths for watermelon and melon transplanting machinery based on laser navigation according to claim 8, characterized in that, S5 includes: S51: After normalizing the lateral position deviation and heading angle deviation, a weighted coupled deviation function is constructed. S52: Based on the segment where the coupling deviation function is located, use a segmented control strategy to generate the steering motor control quantity and the travel speed compensation quantity respectively.

10. The method for automatic correction and optimization of field paths for watermelon and melon transplanting machinery based on laser navigation according to claim 9, characterized in that, S6 includes: S61: Convert the calculated steering motor control quantity and travel speed compensation quantity into the standard signal format required by the hardware control interface; S62: The control angle command and control speed value are synchronously output to the steering servo controller and the walking hydraulic drive unit to control the direction and speed of the implement in real time, realize continuous correction between rows, and the feedback sensor monitors the changes in the attitude of the implement in real time to form a closed-loop control.

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