Automatic row alignment method for corn harvester

Abstract

The invention relates to an automatic row alignment method for a corn harvester, comprising the following steps: installing a detection device on the harvester; marking corn stalks with a marking device to obtain corn stalk coordinates; obtaining vehicle control point coordinates; calculating the lateral offset of the corn stalk relative to the vehicle control point according to the real-time angle change obtained by collision of the detection device and in combination with the corn stalk coordinates and the vehicle control point coordinates; obtaining a coordinate set S of the corn stalk relative to the vehicle origin according to the lateral offset and the vehicle control point coordinates; fitting the obtained coordinate set S through an algorithm to obtain a corn stalk trajectory line L; calculating a heading offset of the vehicle control point relative to the corn stalk trajectory line L according to the corn stalk trajectory line L; setting the obtained lateral offset and heading offset in a controller to realize automatic control, so that the harvester can automatically harvest according to the corn sowing route, and automatically adjust when yaw, thereby improving the harvesting efficiency and reducing the burden on users.

Description

Technical Field

[0001] The invention relates to the field of agricultural automation machinery, and in particular to an automatic row alignment method for a corn harvester. Background Art

[0002] With the continuous advancement of science and technology, my country has been increasingly improving in the research and development of agricultural automation machinery and equipment, and has gradually transformed from traditional manual sowing and harvesting methods to automation, mechanization, and intelligence. However, as a traditional agricultural power, my country still has a lot of room for improvement in the development of automation and intelligence of agricultural machinery. The automation and intelligence of agricultural machinery are of great significance to increasing crop yields and reducing labor costs.

[0003] Corn is one of the most important crops in my country. It has a short harvest period and heavy tasks. Early or late harvest will affect the yield of corn, which requires a certain efficiency in corn harvesting. From the different stages of sowing and harvesting, the harvesting machinery is the weakest in the automation link, which has become the bottleneck of mechanized corn production. With the development of science and technology, harvesters that can replace manual corn harvesting have emerged, but traditional corn harvesters harvest at will according to the operator's wishes when in use. They lack precise harvesting paths, resulting in a long time for corn harvesting. In addition, due to the lack of path planning, the harvester has to move back and forth in multiple paths, which reduces the efficiency of harvesting. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide an automatic row alignment method for a corn harvester to solve one or more problems in the prior art.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] An automatic row alignment method for a corn harvester comprises the following steps:

[0007] Install a detection device on the harvester.

[0008] Use a dotting tool to dot the corn stalks to obtain the coordinates of the corn stalks.

[0009] Get the coordinates of the vehicle control points.

[0010] The lateral offset of the corn stalk relative to the vehicle control point is calculated based on the real-time angle change obtained when the detection device collides and the corn stalk coordinates and the vehicle control point coordinates. The lateral offset calculation formula is as follows:

[0011] EP=R*(1-cos(α+λθ))

[0012] Where: EP: lateral offset of the vehicle.

[0013] R: Length of the detection device.

[0014] α: Angle change of angular displacement feedback.

[0015] λθ: Angle error compensation value obtained from experiments.

[0016] The northeast celestial coordinate set S of the corn stalk relative to the vehicle origin is obtained according to the calculated lateral offset and the coordinates of the vehicle control point.

[0017] The obtained northeast celestial coordinate set S is screened by a clustering algorithm and then fitted to obtain the trajectory line L of the corn stalk.

[0018] The heading offset of the vehicle control point relative to the corn stalk trajectory line L is calculated according to the corn stalk trajectory line L, wherein the heading offset calculation formula is as follows:

[0019] θ e =θ c -arctan(K L )

[0020] Where: θ e : Heading deviation angle.

[0021] θ c : The current heading angle of the vehicle body.

[0022] K L : The slope of the corn stalk fitting line.

[0023] The obtained lateral offset and heading offset are set in the lateral heading controller to realize automatic control.

[0024] Furthermore, the detection device includes a pole arm, and the dual-antenna GNSS positioning is electrically connected to the pole arm.

[0025] Furthermore, the real-time angle change refers to the angle formed by the first position and the second position of the lever arm when the lever arm collides with the corn stalk.

[0026] Furthermore, the northeast celestial coordinate set S is a set of points obtained by converting the above-mentioned vehicle control point coordinates into northeast celestial coordinates relative to the vehicle origin and then combining them with the lateral offset, that is, a set of points of the northeast celestial coordinates of the corn stalk coordinates relative to the vehicle origin.

[0027] Furthermore, the clustering algorithm screening refers to setting the center point of the cluster as a valid point through the K-MEANS algorithm, and processing at least one valid point as an array.

[0028] Furthermore, the calculation formula of the lateral heading controller is as follows:

[0029] J=X T QX+U T PU

[0030] Where: J: error function of the controller.

[0031] X T : EP is the lateral deviation, θ e For deviation, Where t0 is the current time and t1 is the previous time.

[0032] U T : The front wheel angle of the current vehicle.

[0033] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0034] By designing an automatic rowing method for corn harvesters based on a mechanical sensor device and a lateral heading controller, the unmanned driving of the corn harvester is realized, so that the harvester can automatically harvest according to the corn sowing route, and can adjust itself according to the lateral offset and navigation offset when the route deviates from the sowing route, which greatly improves the harvesting efficiency and reduces the burden on users. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A structural schematic diagram showing the installation of a mechanical sensor for an automatic row alignment method for a corn harvester according to an embodiment of the present invention is shown.

[0036] Figure 2 A working principle diagram of a mechanical sensor for an automatic row alignment method of a corn harvester according to an embodiment of the present invention is shown.

[0037] Figure 3 A comparative analysis diagram of corn stalk lateral deviation estimation and actual lateral deviation in an automatic row alignment method for a corn harvester according to an embodiment of the present invention is shown.

[0038] Figure 4 A diagram showing the results of a corn stalk coordinate point clustering experiment for an automatic row alignment method for a corn harvester according to an embodiment of the present invention is shown.

[0039] Figure 5 A diagram showing the experimental results of corn stalk prediction coordinates of an automatic row alignment method for a corn harvester according to an embodiment of the present invention is shown.

[0040] Figure 6 A schematic diagram of a controller based on lateral heading for an automatic row alignment method for a corn harvester according to an embodiment of the present invention is shown.

[0041] Markings in the accompanying drawings: 1, crop divider; 2, detection device; 201, lever arm; 3, first position; 4, second position. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical scheme and advantages of the present invention clearer, the following is a further detailed description of the automatic row alignment method of a corn harvester proposed by the present invention in combination with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structure, proportion, size, etc. illustrated in the drawings of this specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no technical substantive significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effect that the present invention can produce and the purpose that can be achieved, should still fall within the scope of the technical content disclosed by the present invention.

[0043] The automatic row alignment method of the corn harvester of this embodiment includes the following steps:

[0044] Step 1: Please refer to Figure 1 , a detection device 2 is installed on the harvester. Specifically, the detection device 2 is installed at the center of the crop divider 1 of the harvester. The crop divider 1 of the harvester is used to separate crops into two parts, to be cut and to be cut, and the detection device 2 realizes data acquisition when the crop divider 1 processes crops. Specifically, the detection device 2 includes a lever arm 201, and the lever arm 201 is rotatably arranged on the crop divider 1.

[0045] Step 2: The user uses a handheld high-precision dotting device to mark the corn stalks to obtain the coordinates of the corn stalks.

[0046] Step 3: Please continue reading Figure 1 The real-time position information of the vehicle, namely the coordinates of the vehicle control point, is obtained through dual-antenna GNSS positioning. Preferably, in this embodiment, the antenna position is electrically connected and set on the lever arm 201.

[0047] Step 4: Please continue reading Figure 2 , Figure 3 , Figure 5 and Figure 6, when the lever arm 201 collides with the corn stalk, a real-time angle change can be obtained, and the real-time angle change refers to the angle formed by the lever arm 201 at the first position 3 and the second position 4 when the lever arm 201 collides with the corn stalk. Preferably, the lever arm 201 is rotatably arranged on the detection device 2. The lateral deviation of the corn stalk can be estimated through the angle change data, and the actual lateral deviation of the two lever arms 201 and the harvester can be compared and analyzed. The position of the corn stalk is calculated by combining the real-time angle change obtained with the above-mentioned corn stalk coordinates and the vehicle control point coordinates, and the corn stalk prediction coordinate diagram is obtained, and then the lateral offset calculation formula of the corn stalk relative to the vehicle control point is obtained, as shown in the following formula 1:

[0048] EP=R*(1-cos(α+λθ)) (1)

[0049] in:

[0050] EP: The lateral offset of the vehicle.

[0051] R: The length of the probe rod.

[0052] α: Angle change of angular displacement feedback.

[0053] λθ: Angle error compensation value obtained from experiments.

[0054] Step 5: Please continue reading Figure 4 and Figure 6 After setting the initial origin coordinates of the vehicle, the above vehicle control point coordinates and corn stalk coordinates are first converted into northeastern sky coordinates, and then the lateral offset calculated according to the above formula is calculated to obtain the northeastern sky coordinate set S of the corn stalk relative to the vehicle origin. The obtained northeastern sky coordinate set S is screened by a clustering algorithm and then fitted by the least squares method to obtain the trajectory line L of the corn stalk. The clustering algorithm screening refers to setting the center point of the cluster as a valid point through the K-MEANS algorithm, and treating at least one valid point as an array. Preferably, in this embodiment, five valid points are selected as a group for least squares fitting.

[0055] Step 6: Use the obtained corn stalk trajectory line L to calculate the heading offset of the vehicle control point relative to the corn stalk trajectory line L. The heading offset calculation formula is shown in the following formula 2:

[0056] θ e =θ c -arctan(K L ) (2)

[0057] Where: θ e : Heading deviation angle.

[0058] θ c: Current vehicle heading angle obtained by GNSS.

[0059] K L : The slope of the corn stalk fitting line L.

[0060] Step 7: Please continue reading Figure 6 , and set the obtained lateral offset and heading offset in the lateral heading controller. The calculation formula of the lateral heading controller is shown in the following formula 3:

[0061] J=X T QX+U T PU(3)

[0062] Where: J: error function of the controller.

[0063] X T : X T is the parameter matrix, where EP is the lateral deviation,

[0064] θ e For deviation, Where t0 is the current time and t1 is the previous time.

[0065] U T : The front wheel angle of the current vehicle.

[0066] By writing the above formula 3 into the lateral heading controller to realize automatic control of the harvester, the harvester can automatically angle the corn stalks according to their positions to improve the efficiency of the harvesting operation and reduce labor costs.

[0067] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An automatic row alignment method for a corn harvester, characterized in that The following steps are involved: Installing a detection device on the harvester; Use a dotting device to dot the corn stalks to obtain the coordinates of the corn stalks; Get the coordinates of the vehicle control points; The lateral offset of the corn stalk relative to the vehicle control point is calculated based on the real-time angle change obtained when the detection device collides and the corn stalk coordinates and the vehicle control point coordinates. The lateral offset calculation formula is as follows: EP=R*(1-cos(α+λθ)) Where: EP: lateral displacement of the vehicle; R: length of the detection device; α: Angle change of angular displacement feedback; λθ: Angle error compensation obtained from the experiment; The northeast celestial coordinate set S of the corn stalk relative to the vehicle origin is obtained according to the calculated lateral offset and the coordinates of the vehicle control point; The obtained northeast celestial coordinate set S is screened by a clustering algorithm and then fitted to obtain the corn stalk trajectory line L; The heading offset of the vehicle control point relative to the corn stalk trajectory line L is calculated according to the corn stalk trajectory line L, wherein the heading offset calculation formula is as follows: θ e =θ c -arctan(K L ) Where: θ e : heading deviation angle, θ c : The current heading angle of the vehicle body, K L : The slope of the corn stalk fitting line; The obtained lateral offset and heading offset are set in the lateral heading controller to realize automatic control.

2. The automatic row alignment method for a corn harvester according to claim 1, characterized in that: The detection device includes a pole arm, and a dual-antenna GNSS positioning system is electrically connected to the pole arm.

3. The automatic row alignment method for a corn harvester according to claim 2, characterized in that: The real-time angle change refers to the angle formed by the first position and the second position of the lever arm when the lever arm collides with the corn stalk.

4. The automatic row alignment method for a corn harvester according to claim 3, characterized in that: The northeast celestial coordinate set S is a set of points obtained by converting the coordinates of the vehicle control point into the northeast celestial coordinates relative to the vehicle origin and then combining them with the lateral offset, that is, a set of points of the northeast celestial coordinates of the corn stalk coordinates relative to the vehicle origin.

5. The automatic row alignment method for a corn harvester according to claim 4, characterized in that: The clustering algorithm screening refers to setting the center point of the cluster as a valid point through the K-MEANS algorithm, and processing at least one valid point as an array.

6. The automatic row alignment method for a corn harvester according to claim 5, characterized in that: The calculation formula of the lateral heading controller is as follows: J=X T QX+U T PU Where: J: error function of the controller; X T : EP is the lateral deviation, θ e For deviation, Where t0 is the current moment and t1 is the previous moment; U T : The front wheel angle of the current vehicle.

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