A precision fertilizer application device and method

Abstract

The application discloses a precision fertilization device and method thereof, and belongs to the technical field of agricultural mechanization. The device comprises the following: S1, a main body frame, at least one modular fertilization unit, a multi-dimensional state sensing assembly and a controller. The modular fertilization unit, the multi-dimensional state sensing assembly and the controller are arranged on the main body frame. The controller is electrically connected with the multi-dimensional state sensing assembly and the high-precision stepping motor of the modular fertilization unit. The application adopts a fertilization triggering mode based on space coordinate prediction. The controller performs data fusion algorithm processing on high-frequency inertial measurement unit and wheel speed encoder data and low-frequency differential GPS geographic coordinates, generates accurate and continuous high-precision and high-frequency real-time state flow, and accurately describes the position, speed and three-dimensional attitude of the carrier at any time.

Description

Technical Field

[0001] This invention relates to the field of agricultural mechanization, specifically to a precision fertilization device and method. Background Technology

[0002] Traditional agricultural fertilization methods typically rely on time intervals or travel distances to trigger fertilization. This approach faces a series of challenges in actual farmland operations, making it difficult to guarantee the accuracy and uniformity of fertilization.

[0003] Agricultural vehicles often travel at inconsistent speeds in the fields, especially in areas with undulating terrain. If fertilization is still triggered at time intervals when the vehicle speed changes, it will cause deviations in the amount of fertilizer applied per unit distance. For example, if the vehicle slows down when going uphill, triggering fertilization at time intervals will result in excessive fertilization over a short distance.

[0004] Changes in the posture of agricultural vehicles, such as pitching and rolling, can interfere with the uniformity of fertilizer application. When operating on bumpy roads or slopes, the vehicle's posture changes in real time, causing differences in the actual output of each fertilizer application unit. For example: Pitch attitude changes: When the vehicle tilts backward uphill, the fertilizer will be compressed backward under the action of gravity, resulting in poor flow into the push chamber and the actual amount of fertilizer discharged is less than expected; conversely, when tilting forward downhill, the fertilizer will flow forward faster, resulting in the actual amount discharged is more than expected.

[0005] Rolling posture changes: For devices with multiple fertilization units, when the vehicle tilts to the side on a lateral slope, fertilizer will accumulate on the lower side under the action of gravity. This will cause the fertilization units on the lower side to feed too smoothly and discharge too much fertilizer. Meanwhile, the fertilization units on the higher side may experience insufficient feeding and discharge less than expected.

[0006] Current technologies primarily rely on single mileage or time signals to control fertilization, making it difficult to comprehensively consider the instantaneous speed and three-dimensional attitude changes of agricultural vehicles. This results in insufficient precision in the geographical location of fertilization points and uneven fertilization amounts at each point, failing to meet the stringent requirements of modern precision agriculture for equidistant and uniform fertilization. Therefore, there is an urgent need for a precision fertilization technology capable of real-time sensing of the multi-dimensional state of the vehicle and performing spatial prediction and instantaneous composite compensation for fertilization actions.

[0007] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0008] The purpose of this invention is to provide a precision fertilization device and method to solve the problems mentioned in the background art.

[0009] The technical solution of the present invention includes: S1. A main frame, at least one modular fertilization unit, a multi-dimensional state sensing assembly, and a controller are set up, wherein the modular fertilization unit, the multi-dimensional state sensing assembly, and the controller are all arranged on the main frame, and the controller is electrically connected to the high-precision stepper motors of the multi-dimensional state sensing assembly and the modular fertilization unit respectively. S2. The controller obtains the geographic coordinates, attitude and acceleration information, and relative speed information of the agricultural vehicle from the multi-dimensional state perception assembly, and runs a data fusion algorithm to calculate the real-time state of the vehicle based on the high-frequency attitude and acceleration information and the relative speed information, and uses the low-frequency geographic coordinates to periodically calibrate the calculation results to generate a high-precision, high-frequency real-time state stream about the vehicle's current position, speed and attitude. S3. Based on the real-time state flow, the controller calculates the predicted position of the discharge pipe of the modular fertilization unit after a short time according to the current acceleration and angular velocity, and compares the predicted position with the target coordinate point in the preset prescription diagram. When it is determined that the predicted trajectory of the discharge pipe is about to coincide with the target coordinate point, a fertilization trigger command is generated. S4. While generating the fertilization trigger command, the controller performs an instantaneous fertilization amount composite compensation calculation. The calculation comprehensively considers the instantaneous ground speed, pitch attitude and roll attitude of the vehicle in the real-time state stream to determine the precise number of steps and rotation speed required for the high-precision stepper motor of the modular fertilization unit to rotate, and drives the high-precision stepper motor to execute. S5. Repeat steps S2 to S4 until fertilization of all target coordinate points in the prescription map is completed.

[0010] Preferably, in step S4, the composite compensation calculation includes speed compensation: the controller adjusts the instantaneous rotation speed of the high-precision stepper motor according to the instantaneous ground speed when the vehicle passes the target coordinate point, to ensure that the preset amount of fertilizer is pushed out within the time window determined by the speed.

[0011] Preferably, in step S4, the composite compensation calculation includes pitch attitude compensation: the controller finds or calculates a compensation coefficient from a preset correction model describing the relationship between pitch angle and push efficiency based on the real-time pitch angle obtained from the multi-dimensional state perception assembly, and uses the coefficient to adjust the total number of steps of the high-precision stepper motor to offset the interference of terrain slope on the fertilization equivalence.

[0012] Preferably, the method for establishing the correction model is as follows: the device is placed on an adjustable angle platform, and the high-precision stepper motor is made to perform a fixed number of steps at multiple positive and negative pitch angles. The actual amount of fertilizer discharged is measured and compared with the reference weight in the horizontal state to obtain the pushing efficiency deviation rate corresponding to each pitch angle, thereby constructing the correspondence between the pitch angle and the deviation rate.

[0013] Preferably, when multiple modular fertilization units are provided, in step S4, the composite compensation calculation includes roll attitude compensation: the controller calculates different roll compensation coefficients for each independent fertilization unit based on a preset geometric model, according to the real-time roll angle obtained from the multi-dimensional state sensing assembly and combined with the lateral distance of each modular fertilization unit from the center of the vehicle, so as to correct the uneven feeding of each unit caused by the tilt of the vehicle.

[0014] Preferably, the modular fertilization unit includes a fertilizer storage tank mounted on the main frame via a fixed base. The bottom outlet of the fertilizer storage tank is connected to a horizontally arranged spiral pushing cavity. A spiral conveying shaft is provided in the spiral pushing cavity, and the output shaft of the high-precision stepper motor is connected to the spiral conveying shaft.

[0015] A precision fertilization device, comprising: Main framework; At least one modular fertilization unit is installed on the main frame, wherein the modular fertilization unit includes a high-precision stepper motor for quantitatively dispensing fertilizer; A multi-dimensional state perception assembly, fixed to the main frame, is used to collect the position, attitude and speed information of agricultural vehicles in real time; The controller is fixed on the main frame and is electrically connected to the high-precision stepper motor of the multi-dimensional state sensing assembly and the modular fertilization unit.

[0016] Preferably, the multi-dimensional state perception assembly includes: a high-frequency differential GPS receiver for acquiring the absolute geographic coordinates of the vehicle; an inertial measurement unit for sensing the pitch, roll, and yaw attitudes of the vehicle; and a wheel speed encoder signal interface for receiving travel pulse signals.

[0017] Preferably, the modular fertilization unit further includes: The fertilizer storage tank has a horizontally arranged spiral push chamber connected to its lower outlet; A spiral conveyor shaft is housed within the spiral pushing cavity, and the output shaft of the high-precision stepper motor is connected to the spiral conveyor shaft for pushing fertilizer out of the fertilizer storage tank.

[0018] Preferably, the main frame includes an installation crossbeam with a T-shaped groove along its length, and the modular fertilization unit is slidably installed in the T-shaped groove through a fixed base and fixed by locking bolts.

[0019] This invention provides a precision fertilization device and method, which, compared with the prior art, has the following improvements and advantages: 1. This solution adopts a fertilization triggering method based on spatial coordinate prediction, with a high-precision real-time state stream: The controller processes high-frequency inertial measurement unit and wheel speed encoder data with low-frequency differential GPS geographic coordinates using a data fusion algorithm to generate a precise and continuous real-time state stream that accurately describes the vehicle's position, speed, and three-dimensional attitude at any given time. This proactive, spatial coordinate prediction-based triggering method ensures that the fertilization action occurs precisely at a predetermined point in geographic space, rather than based on travel distance or time; even if the agricultural vehicle experiences speed fluctuations during travel or is in complex terrain, the equidistant spatial distance of the fertilization point can still be guaranteed. 2. Simultaneously with generating the fertilization trigger command, the controller performs a composite compensation calculation for the instantaneous fertilization amount. Taking into account the vehicle's instantaneous ground speed, pitch attitude, and roll attitude in the real-time state stream, the controller dynamically adjusts the precise number of steps and rotational speed of the high-precision stepper motor in the modular fertilization unit. Based on the instantaneous ground speed of the vehicle when passing the target coordinate point, the controller adjusts the instantaneous rotational speed of the high-precision stepper motor. For example, when the speed doubles, the rotational speed of the high-precision stepper motor also increases accordingly, ensuring that the total number of motor rotations, i.e., the total amount of fertilizer dispensed, remains constant within the shortened time window. This effectively addresses the issue of inconsistent vehicle speed during operation, ensuring the equalization of fertilization. 3. The controller finds or calculates the compensation coefficient from the preset correction model based on the real-time pitch angle, and uses the coefficient to adjust the total number of steps of the high-precision stepper motor. This compensation corrects the deviation caused by tilting backward on uphill or forward on downhill in terms of fertilizer delivery efficiency. If the uphill delivery efficiency is reduced, the number of steps is increased to ensure that the amount of fertilizer at each fertilization point remains consistent when operating in continuously undulating hilly areas. 4. The modular fertilization unit is slidably installed in the T-shaped groove of the main frame mounting beam through a fixed base and fixed with locking bolts. This installation method provides flexibility and adaptability to the operation. Farmers can easily adjust the lateral spacing between each modular fertilization unit in the field according to the planting row spacing requirements of different crops to meet different fertilization operation needs. Attached Figure Description

[0020] The present invention will be further explained below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall structure of the device; Figure 2 This is a schematic diagram of the modular fertilization unit; Figure 3 This is a schematic diagram of the connection structure of the screw conveyor shaft; Figure 4 This is a schematic diagram of the multi-dimensional state sensing assembly; Figure 5 This is a schematic diagram of the process flow of the method of the present invention.

[0021] In the diagram: 100, main frame; 110, mounting beam; 120, suspension interface; 200, modular fertilization unit; 210, fixed base; 220, fertilizer storage tank; 230, spiral push cavity; 240, spiral conveyor shaft; 250, high-precision stepper motor; 260, discharge pipe; 300, multi-dimensional status sensing assembly; 310, high-frequency differential GPS receiver; 320, inertial measurement unit; 330, wheel speed encoder signal interface; 400, controller. Detailed Implementation

[0022] 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.

[0023] Example 1: Please see Figure 1-5 This invention provides a precision fertilization method, comprising: S1. A main frame 100, at least one modular fertilization unit 200, a multi-dimensional state sensing assembly 300, and a controller 400 are set up. The modular fertilization unit 200, the multi-dimensional state sensing assembly 300, and the controller 400 are all arranged on the main frame 100. The controller 400 is electrically connected to the high-precision stepper motors of the multi-dimensional state sensing assembly 300 and the modular fertilization unit 200, respectively. S2. The controller 400 obtains the geographic coordinates, attitude and acceleration information, and relative velocity information of the agricultural vehicle from the multi-dimensional state perception assembly 300, and runs a data fusion algorithm to calculate the real-time state of the vehicle based on the high-frequency attitude and acceleration information and relative velocity information. It then uses the low-frequency geographic coordinates to periodically calibrate the calculation results to generate a high-precision, high-frequency real-time state stream about the vehicle's current position, velocity and attitude. S3, the controller 400, based on the real-time state flow, calculates the predicted position of the discharge pipe 260 of the modular fertilization unit 200 after a short time according to the current acceleration and angular velocity, and compares the predicted position with the target coordinate point in the preset prescription map. When it is determined that the predicted trajectory of the discharge pipe 260 is about to coincide with the target coordinate point, a fertilization trigger command is generated. S4. While generating the fertilization trigger command, the controller 400 performs an instantaneous fertilization amount composite compensation calculation, which comprehensively considers the instantaneous ground speed, pitch attitude and roll attitude of the vehicle in the real-time state flow, in order to determine the precise number of steps and speed required for the high-precision stepper motor of the modular fertilization unit 200 to rotate, and drives the high-precision stepper motor to execute. S5. Repeat steps S2 to S4 until fertilization of all target coordinate points in the prescription map is completed.

[0024] In one embodiment of the present invention, a precision fertilization method is described. Traditional fertilization methods usually rely on time intervals or travel distances to trigger the application. This method cannot guarantee the accuracy of the fertilization point location and the uniformity of the fertilization amount when the speed of the agricultural vehicle changes or the terrain is uneven. For example, when the vehicle slows down uphill, triggering the application based on time will result in excessive fertilization per unit distance. On bumpy roads, the actual output of each fertilization unit will also vary due to changes in posture.

[0025] The modular equidistant and equal-quantity fertilization method proposed in this embodiment aims to solve the above-mentioned problems. This method collects dynamic information of agricultural vehicles through a multi-dimensional state sensing assembly 300 deployed on the main frame 100. The multi-dimensional state sensing assembly 300 is not a single sensor, but a composite device integrating a high-frequency differential GPS receiver 310, such as u-blox ZED-F9P, an inertial measurement unit 320, such as an MPU-6050 chip module integrating a three-axis gyroscope and a three-axis accelerometer, and a wheel speed encoder signal interface 330. The controller 400, such as a Siemens S7-1200 series PLC or an industrial computer with equivalent performance, receives these data from different sources.

[0026] The data fusion algorithm running on the controller 400 processes this multi-source information. Based on the high-frequency but cumulatively error-prone data provided by the inertial measurement unit 320 and the wheel speed encoder, the algorithm continuously calculates the real-time position and attitude of the vehicle, and then periodically calibrates the calculation results using low-frequency but absolutely accurate geographic coordinates provided by GPS. The purpose of this process is to generate a real-time state stream that is both accurate and continuous, which accurately describes the vehicle's position, velocity, and three-dimensional attitude at any given time.

[0027] The data fusion algorithm is based on extended Kalman filtering or a similar algorithm. In step S2, the data fusion algorithm processes multi-source heterogeneous frequency data by fusing the high-frequency data provided by the inertial measurement unit 320 with the low-frequency data provided by the differential GPS receiver. Input sources: High frequencies from the inertial measurement unit 320, such as 200Hz attitude and acceleration information, high-frequency relative velocity information provided by the wheel speed encoder signal interface 330, and low frequencies from the high-frequency differential GPS receiver 310, such as 10Hz absolute geographic coordinates; Logical steps: Step 1, prediction / calculation: Based on the high-frequency attitude, acceleration, and relative velocity information, the controller 400 calculates the real-time state of the vehicle, including position, velocity, and three-dimensional attitude; Step 2, calibration / update: When low-frequency GPS geographic coordinate data arrives, the controller 400 uses the absolute coordinates to periodically calibrate the state results calculated from the high frequency to correct accumulated errors; Output results and flow: The final output of the process is a high-precision, high-frequency real-time state stream about the vehicle's current position, velocity, and attitude, which is then passed to the position prediction module S3 and the instantaneous fertilizer application composite compensation calculation module S4; The controller 400 performs active position prediction based on the real-time state flow, that is, it calculates the spatial position that the discharge pipe 260 of the modular fertilization unit 200 will reach in a short time based on the current acceleration and angular velocity. The controller 400 continuously compares the predicted location with the target geographic coordinates on the preset prescription map. Once it is determined that the two trajectories are about to overlap, a fertilization trigger command is generated. The core of this triggering method based on spatial coordinate prediction is to ensure that the fertilization action occurs precisely at the predetermined point in geographic space, rather than based on the travel distance or time.

[0028] While generating the trigger command, the controller 400 performs an instantaneous fertilizer application amount composite compensation calculation, which is crucial to ensuring the consistency of fertilizer application. This calculation integrates vehicle speed, pitch attitude, and roll attitude information from the real-time state stream, and dynamically adjusts the motion parameters of the high-precision stepper motors of each modular fertilizer application unit 200. This comprehensive compensation mechanism enables the fertilizer application operation to adapt to complex terrain and changes in driving operation, ensuring that the fertilizer application points are spatially equidistant while achieving uniformity of fertilizer application amount at each point.

[0029] In step S4, the composite compensation calculation includes speed compensation: the controller 400 adjusts the instantaneous speed of the high-precision stepper motor according to the instantaneous ground speed when the vehicle passes the target coordinate point, so as to ensure that the preset amount of fertilizer is pushed out within the time window determined by the speed.

[0030] In this embodiment, the speed compensation in the composite compensation calculation aims to address the situation where the speed of the agricultural vehicle is not constant during operation. When the vehicle approaches the target coordinate point at a higher speed, the time window for it to pass through that point will be shortened accordingly. If the high-precision stepper motor is still running at the standard speed, the preset total amount of fertilizer cannot be pushed within the short time window. Conversely, if the vehicle speed is too slow, it will push too much fertilizer.

[0031] To address this issue, when fertilization is triggered, the controller 400 extracts the instantaneous ground speed of the vehicle as it passes the target point from the real-time state stream. Based on this speed value, the speed compensation logic calculates the shortest time required to complete one standard fertilization cycle and accordingly increases the instantaneous rotation speed of the high-precision stepper motor. For example, if the speed is doubled, the theoretical fertilization time window is halved, so the controller 400 instructs the high-precision stepper motor to increase its rotation speed accordingly to ensure that the total number of steps the motor rotates, i.e., the total amount of fertilizer dispensed, remains constant within the halved time. In this way, speed compensation ensures that regardless of fluctuations in the vehicle's speed, the amount of fertilizer applied at each target point strictly follows the prescription map settings, thus guaranteeing the consistency of fertilization.

[0032] In step S4, the composite compensation calculation includes pitch attitude compensation: the controller 400 finds or calculates the compensation coefficient from the preset correction model describing the relationship between pitch angle and push efficiency based on the real-time pitch angle obtained from the multi-dimensional state perception assembly 300, and uses the coefficient to adjust the total number of steps of the high-precision stepper motor to offset the interference of terrain slope on the fertilization equivalence.

[0033] In this embodiment, the pitch attitude compensation in the composite compensation calculation is mainly used to overcome the physical influence of terrain slope changes on the fertilizer delivery process. When the agricultural vehicle travels uphill, it will tilt backward. At this time, under the action of gravity, some of the fertilizer will tend to accumulate on the rear wall of the fertilizer storage tank 220, resulting in poor flowability into the spiral delivery cavity 230. If the high-precision stepper motor still executes the standard number of steps, the actual amount of fertilizer discharged will be less than expected. Conversely, when going downhill, the fertilizer will accelerate forward due to gravity, resulting in an actual discharge amount greater than expected.

[0034] The pitch attitude compensation function is precisely to correct this deviation caused by gravity. The controller 400 acquires the vehicle's pitch angle in real time through the inertial measurement unit 320. This pitch angle is used as input to query a preset correction model. This correction model stores the correspondence between different pitch angles and the pushing efficiency deviation rate. Based on the found or calculated compensation coefficient, the controller 400 fine-tunes the total number of steps of the high-precision stepper motor in the current fertilization command. For example, if a pitch angle of 5 degrees uphill is detected, the corresponding compensation coefficient of the model may be 1.08. The controller 400 will then adjust the original 1000-step command to 1080 steps to compensate for the decrease in pushing efficiency caused by the uphill slope. Similarly, the number of steps is reduced accordingly when going downhill. This process ensures that the amount of fertilizer at each fertilization point remains consistent even when operating in continuously undulating hilly areas.

[0035] The method for establishing the correction model is as follows: place the device on an adjustable angle platform, and at multiple positive and negative pitch angles, make the high-precision stepper motor execute a fixed number of steps, and weigh the actual amount of fertilizer discharged. Compare it with the benchmark weight in the horizontal state to obtain the pushing efficiency deviation rate corresponding to each pitch angle, thereby establishing the correspondence between pitch angle and deviation rate.

[0036] Push efficiency deviation rate is a quantitative indicator used to characterize the percentage deviation of the actual fertilizer discharge from the baseline fertilizer discharge in the horizontal state at a specific pitch angle. Compensation coefficient It is the core logic multiplier and compensation coefficient of the controller 400 used to adjust the total number of steps of the high-precision stepper motor 250. The logical definition is: Once the compensation coefficient is calculated, it will be used as input for logical judgment, multiplied by the preset total number of steps, to initiate the next fertilization execution action. In this embodiment, the process of establishing the correction model is a pre-calibrated experimental process, the purpose of which is to quantify the specific impact of pitch angle on fertilizer application rate; this process needs to be completed before the equipment leaves the factory or before the start of the operating season; the specific operation is to fix the entire fertilizer application device on a test platform that can precisely adjust and lock the angle.

[0037] The derivation logic of the process is as follows: With the platform perfectly level, the high-precision stepper motor of the modular fertilization unit 200 executes a fixed number of steps, such as 5000 steps, and the weight of the fertilizer discharged in this action is accurately measured using a high-precision electronic scale. This weight is recorded as the baseline weight. After adjusting the platform angle, the high-precision stepper motor executes the same 5000 steps again, and the weight of the discharged fertilizer is measured. The current weight is compared with the baseline weight, and the deviation rate is calculated. For example, if the baseline weight is 100 grams, and 92 grams are discharged at a 5-degree angle, the pushing efficiency deviation rate is -8%. By repeating this operation at multiple positive and negative angle points, such as from -15 degrees to +15 degrees, at a measurement point every 2.5 degrees, a series of angle-deviation rate data pairs can be obtained. These data pairs are stored in the controller 400 to form a data table that can be queried in real time or to generate a continuous function through curve fitting, thus completing the construction of the correction model. This model provides accurate data basis for the controller 400 to perform pitch attitude compensation in actual operation.

[0038] When multiple modular fertilization units 200 are set, in step S4, the composite compensation calculation includes roll attitude compensation: the controller 400 calculates different roll compensation coefficients for each independent fertilization unit based on the real-time roll angle obtained from the multi-dimensional state sensing assembly 300 and the lateral distance of each modular fertilization unit 200 from the center of the vehicle, in order to correct the uneven feeding of each unit caused by the tilt of the vehicle.

[0039] This geometric model aims to accurately estimate the effective stacking height of fertilizer inside each modular fertilization unit 200 based on the real-time roll attitude of the vehicle, in order to correct the problem of uneven feeding caused by tilting.

[0040] This model as a whole characterizes the physical phenomenon and geometric relationship of fertilizer re-accumulating in a conical storage tank under the action of gravity due to the tilting of the carrier, forming an inclined surface. It serves as the basis for correcting the delivery efficiency of each fertilization unit. Its logical structure and data flow are as follows: Model input: Real-time roll angle acquired by the multi-dimensional state-aware assembly 300 The pre-stored lateral distance of each fertilization unit from the center of the vehicle. and the angle of repose of fertilizer ; Model Output: Based on these parameters, the model analyzes the conical geometry of fertilizer storage tank 220 and the planar equations of the inclined fertilizer surface, ultimately outputting the real-time effective stacking height at the inlet of each unit. ; In this embodiment, the roll attitude compensation in the composite compensation calculation is to address the uneven impact caused by the vehicle's tilt on multiple side-by-side modular fertilization units 200 when the agricultural vehicle is traveling or turning on a lateral slope. When the vehicle tilts to the left, the fertilizer in all the fertilizer storage tanks 220 will accumulate to the left under the influence of gravity. This results in an increase in the fertilizer accumulation height at the inlet of the spiral push cavity 230 of the fertilization unit located on the left side of the vehicle, making feeding smoother. However, the fertilizer accumulation height at the inlet of the fertilization unit located on the right side is reduced, which may lead to insufficient feeding.

[0041] Roll attitude compensation addresses this phenomenon by providing independent and differentiated compensation for each fertilization unit. The controller 400 obtains the real-time roll angle from the inertial measurement unit 320, and it also pre-stores the lateral distance between the centerline of each modular fertilization unit 200 and the geometric center of the vehicle. Based on this information, the controller 400 calls a preset geometric model for calculation; this geometric model has parameterized the upper-wide and lower-narrow conical structure of the fertilizer storage tank 220 and the angle of repose of the fertilizer itself, and can calculate the surface morphology of the fertilizer in each tank after tilting in real time according to the input roll angle, and further calculate the effective accumulation height of fertilizer directly above the inlet of each spiral push cavity 230.

[0042] The derivation process of this computational logic may specifically include: A three-dimensional coordinate system is established for the fertilizer storage tank 220 of each modular fertilization unit 200 with its bottom outlet center as the origin, and the surface equation of the inner wall of the tank is established based on its known conical funnel geometric parameters.

[0043] The roll angle is obtained in real time by the inertial measurement unit 320. and the preset fertilizer rest angle Together, they determine a plane equation representing the inclined surface of the fertilizer under the current working conditions. The normal vector of this plane is determined by the roll angle and the direction of gravity.

[0044] By simultaneously solving the surface equations of the inner wall of the tank and the plane equations of the inclined fertilizer surface, the spatial curve where the two intersect can be obtained. Based on this spatial curve, the lateral distance from the center of the carrier to each independent modular fertilization unit 200 can be calculated. The effective accumulation height of fertilizer at the feed inlet of the spiral pushing cavity 230 directly below it. .

[0045] Calculate the real-time stacking height The vehicle is in a horizontal position, that is Reference height at time Comparisons are made using pre-defined functional relationships. To calculate the feed efficiency compensation coefficient of this unit. The relationship can be represented as:

[0046] in, For the first The compensation coefficient for each modular fertilization unit is 200. This represents the real-time effective stacking height of the unit. As the reference height, This is a function or lookup table obtained through experimental calibration that maps the height ratio to the compensation coefficient; the controller 400 uses the calculated... The value is adjusted accordingly to determine the target total number of steps for the high-precision stepper motor in that unit.

[0047] The model compares this height with the reference height in the horizontal state and calculates the current feeding efficiency compensation coefficient for each unit. For fertilization units on the lower side of the tilt, the controller 400 uses a coefficient less than 1 to reduce the total number of motor steps to avoid over-fertilization. Conversely, for units on the higher side, a coefficient greater than 1 is used to increase the total number of motor steps to compensate for insufficient feeding. This method of calculating compensation independently for each unit ensures that all fertilization units arranged laterally can achieve a uniform and accurate amount of fertilizer in any tilt state.

[0048] The modular fertilization unit 200 includes a fertilizer storage tank 220 installed on the main frame 100 via a fixed base 210. The bottom outlet of the fertilizer storage tank 220 is connected to a horizontally arranged spiral pushing cavity 230. A spiral conveying shaft 240 is provided inside the spiral pushing cavity 230, and the output shaft of a high-precision stepper motor is connected to the spiral conveying shaft 240.

[0049] In this embodiment, the mechanical structure of the modular fertilization unit 200 is the foundation for achieving precise control. The fertilizer storage tank 220, as a temporary storage container for fertilizer, has a cone-shaped funnel structure that is wider at the top and narrower at the bottom, which helps the fertilizer to naturally concentrate towards the bottom outlet under the action of gravity.

[0050] The bottom outlet of the fertilizer storage tank 220 is directly connected to the horizontally arranged spiral conveying cavity 230. This cavity is essentially a cylindrical pipe that houses a spiral conveying shaft 240. The spiral conveying shaft 240 is a small auger with spiral blades that fit precisely against the inner wall of the cavity. A high-precision stepper motor 250, such as a NEMA17 series high-precision stepper motor, is fixed to one side of the spiral conveying cavity 230, and its output shaft is directly connected to one end of the spiral conveying shaft 240 via a coupling.

[0051] This connection directly converts the rotational motion of the high-precision stepper motor into the rotational motion of the screw conveyor shaft 240. Each time the high-precision stepper motor receives a pulse command, its output shaft rotates by a fixed, minute angle, thereby driving the screw conveyor shaft 240 to rotate by the corresponding angle. The rotation of the screw conveyor shaft 240, like a screw, steadily pushes the fertilizer that has fallen from the fertilizer storage tank 220 into the cavity forward along the axial direction, ultimately discharging it from the discharge pipe 260 at the other end of the cavity. Since the rotational angle of the high-precision stepper motor is proportional to the number of pulses, the controller 400 can precisely control the rotation amount and speed of the screw conveyor shaft 240 by precisely controlling the total number of pulses sent to the high-precision stepper motor (i.e., the total number of steps) and the pulse frequency (i.e., the rotational speed), thus achieving precise control of the fertilizer discharge amount.

[0052] Because the rotation angle of the high-precision stepper motor 250 is strictly proportional to the number of electrical pulses received, and the rotation of the screw conveyor shaft 240 has a constant, pre-calibrated proportional relationship with the volume of fertilizer discharged, the controller 400 can accurately control the total number of pulses sent to the high-precision stepper motor 250, i.e. the total number of steps, thereby achieving precise and measurable control over the amount of fertilizer discharged in each fertilization action.

[0053] Example 2: Please see Figure 1-4 A precision fertilization device, comprising: Main framework 100; At least one modular fertilization unit 200 is installed on the main frame 100, wherein the modular fertilization unit 200 includes a high-precision stepper motor 250 for quantitatively dispensing fertilizer; The multi-dimensional state perception assembly 300 is fixed on the main frame 100 and is used to collect the position, attitude and speed information of agricultural vehicles in real time. The controller 400 is fixed on the main frame 100. The controller 400 is electrically connected to the high-precision stepper motor 250 of the multi-dimensional state sensing assembly 300 and the modular fertilization unit 200.

[0054] The controller 400 is electrically connected to the high-precision stepper motor 250 of the multi-dimensional state sensing assembly 300 and the modular fertilization unit 200, respectively. The controller 400 can be a Siemens S7-1200 series PLC or an industrial computer with equivalent performance. In this embodiment, the overall structure of a precision fertilization device is described. The main frame 100 is the load-bearing foundation of the entire device. It is connected to an agricultural vehicle, such as the three-point suspension system of a tractor, through a suspension interface 120, ensuring that the device is securely fixed to the rear of the vehicle.

[0055] The modular fertilization unit 200, the multi-dimensional state sensing assembly 300, and the controller 400 are all mounted on the main frame 100, maintaining a constant relative position. The multi-dimensional state sensing assembly 300 is fixed at the geometric center of the main frame 100 to acquire dynamic data that best represents the overall motion state of the entire device. The controller 400 is mounted close to the multi-dimensional state sensing assembly 300 to shorten the transmission distance of the core data line and improve the reliability of signal transmission. The controller 400 is connected to the multi-dimensional state sensing assembly 300 via a shielded cable to receive the collected data. Simultaneously, the controller 400 is connected to the high-precision stepper motor 250 of each modular fertilization unit 200 via another set of cables to send control commands. This integrated physical layout tightly couples the sensing, decision-making, and execution stages, forming the necessary hardware platform for realizing the aforementioned fertilization method.

[0056] The multi-dimensional state perception assembly 300 includes: a high-frequency differential GPS receiver 310 for acquiring the absolute geographic coordinates of the vehicle; an inertial measurement unit 320 for sensing the pitch, roll, and yaw attitudes of the vehicle; and a wheel speed encoder signal interface 330 for receiving travel pulse signals.

[0057] In this embodiment, the internal structure of the multi-dimensional state sensing assembly 300 is further defined. It is a sealed box-like structure integrating multiple sensors to ensure that the internal components are protected from dust and moisture in the farmland working environment.

[0058] A high-frequency differential GPS receiver 310 is mounted at the center of the top surface of the assembly housing to ensure its antenna has a good view of the sky for obtaining the vehicle's absolute geographic coordinates. The inertial measurement unit 320 is physically implemented as a chip module firmly encapsulated in the geometric center of the assembly. This module contains a three-axis gyroscope and a three-axis accelerometer for high-frequency sensing of the vehicle's attitude changes such as pitch, roll, and yaw during travel. The wheel speed encoder signal interface 330 is a standardized electrical interface that connects to the agricultural vehicle's own wheel speed sensors via cable to receive high-frequency travel pulse signals, thereby obtaining high-precision relative speed information. The combination of these three components enables the multi-dimensional state perception assembly 300 to provide all the raw data required by the controller 400 for data fusion algorithms, forming the hardware foundation for achieving high-precision positioning and attitude perception.

[0059] The modular fertilization unit 200 also includes: Fertilizer storage tank 220, with a horizontally arranged spiral pushing cavity 230 connected to its lower outlet; The screw conveyor shaft 240 is housed within the screw pusher cavity 230. The output shaft of the high-precision stepper motor 250 is connected to the screw conveyor shaft 240 and is used to push fertilizer out of the fertilizer storage tank 220.

[0060] In this embodiment, the internal mechanical structure of the modular fertilization unit 200 is further described, which is designed to achieve stable and measurable fertilizer delivery. The fertilizer storage tank 220, as a funnel-shaped container, ensures that the fertilizer can flow smoothly to its bottom outlet.

[0061] The connection between the spiral pushing cavity 230 and the spiral conveying shaft 240 is the core of achieving quantitative feeding. As long as the rotational motion of the high-precision stepper motor can be accurately transmitted to the spiral conveying shaft 240, it can be used in this invention, and the specific connection structure is not limited. One possible implementation is that the output shaft of the high-precision stepper motor 250 is connected to the spiral conveying shaft 240 through a flexible coupling. This method can compensate for certain installation coaxiality errors and protect the motor bearings. Another possible implementation is to connect it through a set of small synchronous pulleys and a synchronous belt. This method allows adjustment of the transmission ratio without changing the motor's installation direction. Regardless of the method used, the function is to convert the precise angular displacement of the high-precision stepper motor into the precise rotation of the spiral conveying shaft 240, thereby discharging fertilizer from the fertilizer storage tank 220 in a controllable amount.

[0062] The main frame 100 includes an installation crossbeam 110 with a T-shaped groove along its length. The modular fertilization unit 200 is slidably installed in the T-shaped groove through a fixed base 210 and fixed by locking bolts.

[0063] In this embodiment, the specific structure of the main frame 100 and its installation method with the modular fertilization unit 200 are further defined; the core component of the main frame 100 is a high-strength metal mounting beam 110. One or more T-shaped grooves extending along the length direction are machined on the upper surface or side of the beam.

[0064] The modular fertilization unit 200 is connected to the T-shaped slide rail via a fixed base 210. The fixed base 210 is equipped with a T-shaped nut or slider that matches the internal cavity of the T-shaped slide rail; this allows the entire modular fertilization unit 200 to slide freely along the length of the mounting beam 110. After the position is determined, the unit can be securely locked in any position on the beam by tightening the locking bolts on the fixed base 210.

[0065] The purpose of this T-shaped chute installation method is to provide operational flexibility and adaptability. Farmers can easily adjust the lateral spacing between each modular fertilization unit 200 in the field according to the planting row spacing requirements of different crops, without the need for complicated tools or structural modifications to the equipment. This allows the same fertilization device to serve a variety of different planting scenarios, enhancing the equipment's structural adaptability to different operating environments.

[0066] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0067] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A precision fertilization method, characterized in that, include: S1. A main frame (100), at least one modular fertilization unit (200) with a high-precision stepper motor and a discharge pipe, a multi-dimensional state sensing assembly (300), and a controller (400) are provided. The modular fertilization unit (200), the multi-dimensional state sensing assembly (300), and the controller (400) are all arranged on the main frame (100). The controller (400) is electrically connected to the high-precision stepper motor of the multi-dimensional state sensing assembly (300) and the modular fertilization unit (200), respectively. S2. The controller (400) obtains the geographic coordinates, attitude and acceleration information, and relative speed information of the agricultural vehicle from the multi-dimensional state perception assembly (300), and runs a data fusion algorithm to calculate the real-time state of the vehicle based on the high-frequency attitude and acceleration information and the relative speed information, and periodically calibrates the calculation results using the low-frequency geographic coordinates to generate a high-precision, high-frequency real-time state stream about the vehicle's current position, speed and attitude. S3. Based on the real-time state flow, the controller (400) calculates the predicted position of the discharge pipe (260) of the modular fertilization unit (200) after a short time according to the current acceleration and angular velocity, and compares the predicted position with the target coordinate point in the preset prescription diagram. When it is determined that the predicted trajectory of the discharge pipe (260) is about to coincide with the target coordinate point, a fertilization trigger command is generated. S4. While generating the fertilization trigger command, the controller (400) performs an instantaneous fertilization amount composite compensation calculation. The calculation comprehensively considers the instantaneous ground speed, pitch attitude and roll attitude of the vehicle in the real-time state stream to determine the precise number of steps and speed required for the high-precision stepper motor of the modular fertilization unit (200) to rotate, and drives the high-precision stepper motor to execute. S5. Repeat steps S2 to S4 until fertilization of all target coordinate points in the prescription map is completed.

2. The precision fertilization method according to claim 1, characterized in that, In step S4, the composite compensation calculation includes speed compensation: the controller (400) adjusts the instantaneous rotation speed of the high-precision stepper motor according to the instantaneous ground speed when the vehicle passes the target coordinate point, so as to ensure that the preset amount of fertilizer is pushed out within the time window determined by the speed.

3. The precision fertilization method according to claim 2, characterized in that, In step S4, the composite compensation calculation includes pitch attitude compensation: the controller (400) finds or calculates a compensation coefficient from a preset correction model describing the relationship between pitch angle and push efficiency based on the real-time pitch angle obtained from the multi-dimensional state perception assembly (300), and uses the coefficient to adjust the total number of steps of the high-precision stepper motor to offset the interference of terrain slope on the fertilization equivalence.

4. The precision fertilization method according to claim 3, characterized in that, The method for establishing the correction model is as follows: the device is placed on an adjustable angle platform, and the high-precision stepper motor is made to execute a fixed number of steps at multiple positive and negative pitch angles. The actual amount of fertilizer discharged is measured and compared with the reference weight in the horizontal state to obtain the pushing efficiency deviation rate corresponding to each pitch angle, thereby constructing the correspondence between the pitch angle and the deviation rate.

5. The precision fertilization method according to claim 4, characterized in that, When multiple modular fertilization units (200) are provided, in step S4, the composite compensation calculation includes roll attitude compensation: the controller (400) calculates different roll compensation coefficients for each independent fertilization unit based on a preset geometric model, according to the real-time roll angle obtained from the multi-dimensional state sensing assembly (300) and the lateral distance of each modular fertilization unit (200) from the center of the vehicle, so as to correct the uneven feeding of each unit caused by the tilt of the vehicle.

6. The precision fertilization method according to claim 5, characterized in that, The modular fertilization unit (200) includes a fertilizer storage tank (220) installed on the main frame (100) via a fixed base (210). The bottom outlet of the fertilizer storage tank (220) is connected to a horizontally arranged spiral pushing cavity (230). A spiral conveying shaft (240) is provided inside the spiral pushing cavity (230). The output shaft of the high-precision stepper motor is connected to the spiral conveying shaft (240).

7. A precision fertilization device, applied to the precision fertilization method according to any one of claims 1 to 6, characterized in that, include: Main framework (100); At least one modular fertilization unit (200) is installed on the main frame (100), wherein the modular fertilization unit (200) includes a high-precision stepper motor (250) for quantitatively dispensing fertilizer. A multi-dimensional state perception assembly (300) is fixed on the main frame (100) and is used to collect the position, attitude and speed information of agricultural vehicles in real time; The controller (400) is fixed on the main frame (100) and is electrically connected to the high-precision stepper motor (250) of the multi-dimensional state sensing assembly (300) and the modular fertilization unit (200).

8. The precision fertilization device according to claim 7, characterized in that, The multi-dimensional state perception assembly (300) includes: a high-frequency differential GPS receiver (310) for acquiring the absolute geographic coordinates of the vehicle; an inertial measurement unit (320) for sensing the pitch, roll and yaw attitudes of the vehicle; and a wheel speed encoder signal interface (330) for receiving travel pulse signals.

9. A precision fertilization device according to claim 7, characterized in that, The modular fertilization unit (200) also includes: Fertilizer storage tank (220), with a horizontally arranged spiral push chamber (230) connected to its lower outlet; A spiral conveyor shaft (240) is housed within the spiral push cavity (230), and the output shaft of the high-precision stepper motor (250) is connected to the spiral conveyor shaft (240) for pushing fertilizer out of the fertilizer storage tank (220).

10. A precision fertilization device according to claim 7, characterized in that, The main frame (100) includes an installation crossbeam (110) with a T-shaped groove along its length. The modular fertilization unit (200) is slidably installed in the T-shaped groove through a fixed base (210) and fixed by locking bolts.

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