A method and apparatus for precision on-target spray control

Abstract

The present application relates to the technical field of accurate target spraying, and specifically relates to a precise target spraying control method and a matching device, which comprises a main controller, a water supply pipe, a spray rod suspension frame and a pendulum type nozzle module. The spray rod suspension frame is installed at the front of a vehicle, the pendulum type nozzle module is installed at the spray rod suspension frame at equal intervals and is connected to the main controller through a cable, the nozzle of the pendulum type nozzle module is connected to an external water supply system through the water supply pipe, a camera is installed on the spray rod suspension frame, and the main controller and the camera are connected through a cable. The pendulum type nozzle can adjust the direction of the nozzle according to instructions, so that the central axis of the nozzle is perpendicular to the target and spraying is performed. Compared with the existing target spraying mode using the "nearest principle" mode, the present application has the advantage of higher spraying accuracy, which can effectively improve the utilization rate of pesticides and reduce soil pollution.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of precise target spraying, and particularly relates to a precise target spraying control method and a matching device. BACKGROUND

[0002] Pesticide spraying is the main means of crop disease, pest and weed control in China, and has made great contributions to crop yield and quality improvement. However, the overuse of pesticides in recent years has brought about problems such as pesticide damage, high chemical residue, reduced species diversity and environmental pollution, which seriously hinder the sustainable development of agriculture. The key to solving the problem of overuse of pesticides is to improve the utilization rate of pesticides. According to research, the lost part of pesticides during application includes about 20% of fine mist droplets lost to the air with air flow, and about 40% of the part lost or rolled off the target due to mist droplet accumulation. Therefore, precise control of the amount of pesticide to reduce the part sprayed directly to the ground and reduce the rolling caused by mist droplet accumulation is an important way to improve the utilization rate of pesticides. Target spraying technology can identify specific spraying targets through a machine vision system and only spray pesticides on these targets, avoiding spraying pesticides to non-target areas, thereby achieving the purpose of improving the utilization rate of pesticides, reducing the use of pesticides and reducing environmental pollution.

[0003] The essence of target spraying is to spray only when the nozzle passes over the target. The target on the camera is a two-dimensional irregular shape. After target detection by machine vision, a target bounding box is generated, and the position and size attributes of the box are generally used as the position and size attributes of the target. Therefore, the target requires the nozzle to be aligned with the target in two dimensions, i.e., the "forward direction" and the "direction along the spray bar". Different target spraying devices have different methods for aligning the target in the above two dimensions.

[0004] Existing target spraying devices fix the nozzles on the spray bar, and the nozzles are uniformly arranged in the direction of the spray bar. The nozzles are vertically downward, and the nozzle spacing is matched with the spray angle of the nozzle, which can achieve full coverage of the spray bar operation area. Each nozzle is controlled by a separate electromagnetic valve to control the opening and closing time. In terms of target alignment in the "forward direction", a scheme of calculating the delay time by measuring the distance and vehicle speed is generally used to control the spraying time and stopping time. In terms of target alignment in the "direction along the spray bar", the "nearest principle" is adopted, i.e., assigning the "nozzle closest to the target center" or the "nozzle overlapping the most with the target in the direction along the spray bar" to spray. When the operation task of the target spraying device is weeding, the position of the weeds appears randomly, and the fixed nozzle spray bar cannot ensure that the nozzle is "directly opposite" the target each time, so the accuracy of target spraying is not high. Reducing the nozzle spacing can improve the accuracy, but due to structural limitations, it is ultimately impossible to ensure accurate target alignment in the "direction along the spray bar".

[0005] Therefore, the existing target spraying has the following disadvantages:

[0006] (1) In the "along the spray bar direction", the nozzle center and the target center overlap probability is low, resulting in low overlap rate of the mist deposition area and the target area, and the pesticide liquid will be deposited on the ground, which has the disadvantage of more soil pesticide residue;

[0007] (2) In order to improve the overlap rate of the mist deposition area and the target area, the existing spray bar needs to increase the number of nozzles and reduce the nozzle spacing, which on the one hand increases the manufacturing cost, and on the other hand cannot completely solve the problem. SUMMARY

[0008] In view of the above-mentioned defects and problems, the present application provides a precise target spraying control method and a matching device. The pendulum type spray head can adjust the nozzle pointing according to the instruction, so that the nozzle center axis is directly opposite to the target and sprays. Compared with the existing target spraying mode using the "nearest principle" mode, the present application has the advantage of higher spraying accuracy, which can effectively improve the utilization rate of pesticides and reduce soil pollution.

[0009] The technical problem of the present application is solved by the following scheme: a precise target spraying control method and a matching device, comprising a main controller, a water supply pipe, a spray bar suspension frame and a pendulum type spray head module, characterized in that the spray bar suspension frame is installed at the front of the vehicle, the pendulum type spray head module is installed at equal intervals on the spray bar suspension frame, the pendulum type spray head module is connected with the main controller through a cable, the nozzle of the pendulum type spray head module is connected with the external water supply system through the water supply pipe, a camera is installed on the spray bar suspension frame, and the main controller and the camera are connected through a cable; the pendulum type spray head module is composed of a rudder, a control box shell, a bearing and an electromagnetic valve, the rudder is fixed on the control box shell, the output shaft of the rudder extends out of the control box shell, a rudder disc is connected with the output shaft, the rudder disc is connected with the electromagnetic valve, the input end of the electromagnetic valve body is connected with the water supply pipe, the output end of the electromagnetic valve body is connected with the nozzle, and the electromagnetic valve is connected with the control panel in the control box through an electromagnetic valve control line, and the lower end of the control box shell is fixed with a laser ranging module, and the laser ranging module is connected with the control panel in the control box;

[0010] The control method of the precise target spraying device comprises the following steps:

[0011] S1, establish a spray bar coordinate system, in which the rotation axis of the pendulum type spray head module located in the middle of the spray bar suspension frame is the x axis, the forward direction is the positive direction of the x axis, the intersection of the nozzle center axis and the x axis is the origin, the vertical direction is the z axis, and the downward direction is the positive direction of the z axis. The right side of the forward direction is the y axis, the coordinate system satisfies the right hand rule; sort the pendulum type spray head module and the spraying target along the positive direction of the y axis, calculate the coordinate Y of the spray head i on the y axisi , and the z-axis coordinate z of the top of the target j is collected by the camera j , the crown layer center coordinate (x j , y j ), the length l j and the width w j of the target are calculated;

[0012] S2, when the coordinates of the jth target satisfy , the main controller assigns a target nozzle to the target and sends a control message to the pendulum nozzle module;

[0013] where t d is the time consumption of image acquisition and target detection, t s is the time consumption of control message transmission and analysis, t v is the time consumption of the opening process of the electromagnetic valve, t w is the time consumption from the ejection of the droplet from the nozzle to the deposition on the target, t c is the time consumption of the angle adjustment of the rudder, v is the ground speed of the nozzle, and l j is the length of the target j in the x-axis direction;

[0014] The principle of the main controller assigning a target nozzle to the target is as follows: first, the distance dis ji =(y j -y i ) between the target and all nozzles is calculated, and the nozzle corresponding to the smallest positive number in dis ji is set as the target nozzle; if the working state of the nozzle is occupied, the nozzle with the serial number i+1 is assigned as the target nozzle;

[0015] The control message contains four parameters: the rudder angle θ i , the target distance (x j -0.5l j ), the target length l j , and the vehicle speed v, wherein the rudder angle is calculated by the following formula:

[0016] ;

[0017] S3, after receiving the control message, the pendulum nozzle module controls the rudder to drive the nozzle to rotate, so that the axis of the nozzle points to the direction of the angle, and the pendulum nozzle module is controlled to spray in the direction;

[0018] S4, the time length T1 of the delayed spraying is calculated by dividing the distance between the target and the nozzle by the vehicle speed, the spraying time T2 is calculated according to the target length divided by the vehicle speed, T1 is transmitted to the timer of the single-chip microcomputer, when the timer reaches T1, a control signal is sent to open the electromagnetic valve to start spraying, and at the same time, T2 is transmitted to another timer of the single-chip microcomputer to start timing, and the spraying is stopped when the timing reaches T2.

[0019] Further, the number of the pendulum type spray head modules is odd N, and the camera is installed at the top center of the spray rod hanger.

[0020] Further, the main controller is composed of a microcomputer and a display screen, and the power line of the main controller is connected with the vehicle-mounted power supply.

[0021] Further, the spray rod hanger is also provided with a speed measuring device, and the speed measuring device is installed at a position where the speed of the vehicle can be obtained.

[0022] Further, the single spray head of the pendulum type spray head module is connected with the external main controller through a four-core cable, wherein two cores are power lines, and the other two cores are RS485 communication lines, which are connected with the built-in single-chip microcomputer serial port after being converted into TTL level, and the single-chip microcomputer receives the control message sent by the external main controller through the serial port interrupt mode.

[0023] The present application has the following advantages: the present application proposes a brand-new target spraying spray head single structure, designs a matching control method, and designs a spray rod structure composed of multiple spray heads. In the process of vehicle advancing, when a target needing spraying is found, the corresponding pendulum type spray head is allocated to point to the target, the electromagnetic valve is opened to start spraying when the target enters the spraying range of the spray head, and the electromagnetic valve is closed to stop spraying when the target moves out of the spraying range of the spray head. The pendulum type spray head designed by the present application can adjust the nozzle pointing direction according to the instruction, so that the nozzle center axis is perpendicular to the target and spraying is carried out. Compared with the existing target spraying mode using the "nearest principle" mode, the present application has the advantage of higher spraying accuracy, can effectively improve the utilization rate of pesticides and reduce soil pollution, and the accurate spraying direction and angle control ensure that the pesticides can be accurately sprayed on the target, reduce the deposition of pesticides in non-target areas, thereby improving the utilization rate of pesticides and reducing the waste of pesticides. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a schematic diagram of the pendulum type spray head module structure of the present application.

[0025] Figure 2 It is a schematic diagram of the spray rod type target spraying device structure of the present application.

[0026] Figure 3 It is a schematic diagram of the spray rod coordinate system of the present application.

[0027] In the figure: 1, main controller; 2, water supply pipe; 3, camera; 4, spray rod hanger; 5, pendulum type spray head module; 51, rudder; 52, control box top cover; 53, control box shell; 54, laser ranging module; 55, L-shaped aluminum profile; 56, fixing frame; 57, nozzle; 58, bearing; 59, U-shaped aluminum profile; 510, electromagnetic valve; 511, electromagnetic valve control line; 6, cable. DETAILED DESCRIPTION

[0028] The application is further illustrated below in conjunction with the accompanying drawings and examples.

[0029] Referring to Figures 1-3 The application provides a precise on-target spraying control method and a matching device.

[0030] Example 1: The present example provides a precise on-target spraying device

[0031] According to Figure 1 As shown in the figure, the spray rod type on-target spraying device mainly comprises a main controller 1, a water supply pipe 2, a camera 3, a spray rod suspension bracket 4, a pendulum type spray head module 5, and a cable 6. Among them, the spray rod type on-target spraying device is installed in front of the vehicle through the spray rod suspension bracket 4, the input end of the water supply pipe 2 is connected with the vehicle-mounted stable water supply system, and the output end is connected with each pendulum type spray head module 5, the pendulum type spray head module 5 is installed at equal intervals on the spray rod suspension bracket 4, the fixed frame of the pendulum type spray head module 5 is fixed on the lower end of the spray rod suspension bracket 4 through bolts and nuts, the pendulum type spray head module 5 is individually connected with the main controller 1 through the cable 6, the fluid input port of the electromagnetic valve of the pendulum type spray head module 5 is connected with the external water supply system through the water supply pipe 2, the main controller 1 is composed of a microcomputer and a display screen, the power line of the main controller 1 is connected with the vehicle-mounted power supply, the camera 3 is installed in the middle position at the top of the spray rod suspension bracket 4, and the main controller 1 and the camera 3 are connected through the cable 6. The device is also provided with a speed measuring device, which is installed at a position where the speed of the vehicle can be obtained.

[0032] As Figure 2As shown, the pendulum-type nozzle module 5 consists of a servo motor 51, a control box top cover 52, a control box housing 53 (containing a control board), a laser ranging module 54, an L-shaped aluminum profile 55, a mounting bracket 56, a nozzle 57, a bearing 58, a U-shaped aluminum profile 59, a solenoid valve 510, and a solenoid valve control line 511. The servo motor 51 is fixed to the control box housing 53 by bolts and nuts. The control box housing 53 has a control box top cover 52 on the rear side. The short side of the L-shaped aluminum profile 55 and the fixing bracket 56 are stacked and fixed to the front side of the control box housing 53 by screws. The two sides of the U-shaped aluminum profile 59 are connected to the long sides of the two L-shaped aluminum profiles 55 by screws. The outer ring of the bearing 58 is tightly fitted with the U-shaped aluminum profile 59. The output shaft of the servo motor 51 extends out of the control box housing 53. A servo disc is connected to the output shaft. The servo disc is connected to the mounting hole of the solenoid valve 510 by screws. The coil locking nut of the solenoid valve 510 is tightly fitted with the inner ring of the bearing 58. The input end of the solenoid valve body is connected to the water supply pipe 2, and the output end is connected to the nozzle 57. The solenoid valve control line 511 passes through the control box housing 53 and is connected to the control board inside the control box. A laser ranging module 54 is fixed at the lower end of the control box housing 53 and is connected to the control board inside the control box.

[0033] In practical use, the present invention provides a precise target spray control method and supporting device. During the vehicle's forward movement, the camera 3 collects images in real time. When a target that needs to be sprayed is detected, a signal is sent to the main controller 1. The main controller 1 then assigns a corresponding pendulum-type nozzle module 5 to point at the target. The output shaft of the servo motor 51 controls the nozzle 57 to rotate to a specified angle. When the target enters the spray range, the solenoid valve 510 is opened, and water is supplied to the nozzle from the water supply pipe 2 to start spraying. When the target moves out of the spray range of the nozzle, the solenoid valve is closed to stop spraying.

[0034] The angle control of the pendulum nozzle module 5 can be achieved through various means. In addition to servo motors, servo motors, stepper motors, DC motors, encoders, electric actuators, rotary platforms, gyroscopes, and accelerometers can also be used to control the nozzle rotation angle.

[0035] Example 2: This example provides a precise target spray control method.

[0036] like Figure 3 As shown, a spray boom coordinate system is established. In the spray boom coordinate system, the rotation axis of the pendulum-type nozzle module 5 located in the middle of the spray boom suspension frame 4 is taken as the x-axis, the forward direction is taken as the positive x-axis, the intersection of the nozzle central axis and the x-axis is taken as the origin, the vertical direction is taken as the z-axis, the downward direction is taken as the positive z-axis, the direction along the spray boom is taken as the y-axis, and the right side of the forward direction is taken as the positive y-axis. The coordinate system satisfies the right-hand rule.

[0037] In the spray bar coordinate system, the length of the spray bar is denoted as L, the number of the pendulum target-aiming spray head modules installed on the spray bar is denoted as N, N is a single number, the pendulum target-aiming spray heads are distributed at equal intervals along the direction of the spray bar suspension frame 4, the interval is d = L / (N-1), the pendulum spray head modules 5 are sorted in ascending order along the positive direction of the y-axis, the serial number is denoted as i, -((N-1) / 2)≤i≤((N-1) / 2), the serial number of the spray head at the origin of the y-axis is i = 0, the serial number of the spray head in the negative direction of the y-axis is i < 0, and the serial number of the spray head in the positive direction of the y-axis is i > 0. Denote Y i as the coordinate of the spray head i on the y-axis, Y i =i×d, the ground speed of the nozzle 57 is the same as the vehicle speed of the spray bar sprayer, denoted as v. The z-axis coordinate of the top of the target is z j =(H-h), the coordinates of the center of the canopy are (x j , y j ), the length (x-axis direction) and the width (y-axis direction) of the target are l j and w j , respectively, wherein H is the vertical height of the rotation axis of the pendulum target-aiming spray head from the ground, h is the plant height of the target plant, and j is the serial number of the target.

[0038] The target parameters in the above spray bar coordinate system are obtained by coordinate transformation from the target parameters in the image coordinate system, and the target parameters in the image coordinate system are determined by a target detection algorithm.

[0039] When the x-coordinate of the center of the jth target satisfies the following formula, the main controller 1 assigns the corresponding spray head to the target and sends a control message to the spray head:

[0040] (1)

[0041] In the formula, t d is the time consumption of image acquisition and target detection, t s is the time consumption of control message transmission and analysis, t v is the time consumption of the opening process of the electromagnetic valve, t w is the time consumption from the ejection of the liquid droplets from the nozzle to the deposition on the target, and t c is the time consumption of the angle adjustment of the steering engine 51.

[0042] The principle of assigning the target-aiming spray head to the target by the main controller 1 is as follows: first, calculate the distance dis ji =(y j -y i ) between the target and all spray heads, dis jiThe nozzle corresponding to the minimum positive number is set as the target spraying nozzle, if the working state of the nozzle is the occupied state (the target has been assigned and the spraying has not been completed), the nozzle with the serial number of i+1 is the target spraying nozzle, that is, the first to N-1th nozzles preferentially take charge of the target in the area on the right side (the positive direction of y axis) of the nozzles, and only when the coordination information is received, the second to Nth nozzles take charge of the area on the left side of the nozzles.

[0043] The main controller 1 sends the control message to the nozzle assigned to spray by the way of serial communication, the control message contains four parameters of the rudder 51 angle θ i , target distance (x j -0.5l j ), target length l j and vehicle speed v, wherein the rudder 51 angle is calculated by the following formula:

[0044] (2)

[0045] In the formula, i is the serial number of the assigned nozzle.

[0046] The single nozzle of the pendulum type nozzle module 5 is connected with the external main controller 1 through the four-core cable, wherein two cores are power supply lines, and the other two cores are RS485 communication lines, which are connected with the built-in single-chip microcomputer serial port after being converted into TTL level, the single-chip microcomputer receives the control message sent by the external main controller 1 through the serial port interrupt mode, and the control message contains four parameters: the rudder angle, the target distance, the target length and the vehicle speed. After receiving the control message, the single-chip microcomputer firstly converts the rudder angle into a certain duty ratio PWM wave output to the rudder 51, the rudder 51 drives the nozzle to rotate and points the axis to the angle direction; secondly, the time T1 of the delayed spraying is solved by dividing the distance between the target and the nozzle by the vehicle speed, and the spraying time T2 is solved according to the target length divided by the vehicle speed, T1 is transmitted to the timer of the single-chip microcomputer, when the timer reaches T1, the control signal is sent to open the electromagnetic valve to start spraying, and at the same time, T2 is transmitted to another timer of the single-chip microcomputer to start timing, when the timing reaches T2, the spraying is stopped.

[0047] In the embodiment, the number of nozzles installed on the spray rod suspension frame is preset as an odd number, but in practice, the number of nozzles can also be even, when the number of nozzles is even, the camera is installed in the middle of the N / 2, N / 2+1th nozzles.

[0048] The above only describes the preferred embodiment of the present application, and does not limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A precision on target spraying apparatus comprising a master controller, a water supply hose, a spray boom hanger, a pendulum head module, characterized in that, The spray rod hanger is installed in front of the vehicle, the pendulum spray head modules are installed on the spray rod hanger at equal intervals, the pendulum spray head modules are connected with the main controller through a cable, the nozzles of the pendulum spray head modules are connected with an external water supply system through a water supply pipe, a camera is installed on the spray rod hanger, and the main controller and the camera are connected through a cable; the pendulum spray head module is composed of a rudder, a control box shell, a bearing and an electromagnetic valve, the rudder is fixed on the control box shell, an output shaft of the rudder extends out of the control box shell, a rudder disc is connected to the output shaft, the rudder disc is connected with the electromagnetic valve, an input end of a valve body of the electromagnetic valve is connected with the water supply pipe, an output end of the valve body of the electromagnetic valve is connected with the nozzle, the electromagnetic valve is connected with a control panel in the control box through an electromagnetic valve control line, and a laser ranging module is fixed to a lower end of the control box shell and connected with the control panel in the control box. The control method of the precise target spraying device comprises the following steps: S1, establish a spray bar coordinate system, in the spray bar coordinate system, the rotation axis of the pendulum type nozzle module located in the middle of the spray bar suspension frame is the x axis, the forward direction is the positive direction of the x axis, the intersection of the nozzle center axis and the x axis is the origin, the vertical direction is the z axis, downward is the positive direction of the z axis, along the spray bar direction is the y axis, the right side of the forward direction is the positive direction of the y axis, the coordinate system satisfies the right-hand rule; sort the pendulum type nozzle module and the spray target along the positive direction of the y axis, calculate the coordinate Y of the nozzle i on the y axis i , and collect the z axis coordinate z of the top of the target j through the camera j , the crown center coordinate (x j , y j ), the length l j and the width w j of the target S2, when the coordinates of the jth target satisfy the main controller assigns a target nozzle to the target and sends a control message to the pendulum nozzle module. where t d is the time cost of image acquisition and target detection, t s is the time cost of control message transmission and analysis, t v is the time cost of the opening process of the electromagnetic valve, t w is the time cost of the droplet from the nozzle to the target, t c is the time cost of the steering wheel to adjust the angle, v is the ground speed of the nozzle, l j is the length of the target j in the x-axis direction; The principle of the main controller assigning a target to a target nozzle is as follows: first, the distance dis between the target and all the nozzles is calculated ji = (y j -y i ), dis ji The nozzle corresponding to the smallest positive number among the distances is set as the target spraying nozzle. If the working state of the nozzle is an occupied state, the nozzle with the serial number i+1 is assigned as the target spraying nozzle. The control packet contains four parameters of rudder angle θ i , target distance (x j -0.5l j ), target length l j , and vehicle speed v, wherein the rudder angle is calculated by the following formula: ； S3, after receiving the control message, the pendulum spray head module controls the rudder to drive the nozzle to rotate, so that the axis of the nozzle points to the angle direction, and the pendulum spray head module sprays in the direction; S4, the distance between the target and the nozzle is divided by the vehicle speed to obtain the time length T1 of the delayed spraying, the length of the target is divided by the vehicle speed to obtain the spraying time length T2, T1 is transmitted to the timer of the single-chip microcomputer, when the timer reaches T1, a control signal is sent to open the electromagnetic valve to start spraying, and T2 is transmitted to another timer of the single-chip microcomputer to start timing, and the spraying is stopped when the timing reaches T2.

2. A precision on target spraying device according to claim 1 wherein, When the number of the pendulum spray head modules is an odd number N, the camera is installed at the top center position of the spray rod hanger.

3. A precision on target spraying device according to claim 1, wherein, The main controller is composed of a microcomputer and a display screen, and a power line of the main controller is connected with a vehicle-mounted power supply.

4. A precision on target spraying apparatus according to claim 1 wherein, The spray rod hanger is also provided with a speed measuring device, and the speed measuring device is installed at a position where the vehicle speed can be obtained.

5. A precision on target spraying device according to claim 1, wherein, The single spray head of the pendulum spray head module is connected with an external main controller through a four-core cable, two cores of which are power lines, and the other two cores are RS485 communication lines, which are connected with a built-in single-chip microcomputer serial port after being converted into TTL level, and the single-chip microcomputer receives the control message sent by the external main controller through the serial port interrupt mode.

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