A full-chain closed-loop seeding depth control device and method based on image perception

Abstract

A full-chain closed-loop sowing depth control device and method based on image perception relates to the field of agricultural machinery technology. A front frame and a rear frame are set on the top of the frame. The camera is positioned in front of the top of the front frame for collecting ground distance information and transmitting it to the controller in real time. The depth-limiting arm is arranged obliquely at the rear of the bottom of the frame and is hinged to the frame in the middle. The top of the rear frame is hinged to the bottom end of the electric push rod. The telescopic end of the electric push rod is hinged to the upper end of the depth-limiting arm. The depth-limiting wheel is rotatably connected to the lower end of the depth-limiting arm. The furrowing disc is installed in front of the depth-limiting wheel. The controller sends instructions to the electric push rod, and the height of the depth-limiting wheel is adjusted by the telescopic adjustment of the electric push rod to control the furrowing disc to perform furrowing operations of different depths. Based on the ground distance information collected by the camera, the depth of the furrowing disc into the soil can be adaptively changed under conditions of undulating terrain, thereby achieving fixed-depth sowing.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural machinery, and in particular to a full-chain closed-loop sowing depth control device and method based on image perception. Background Art

[0002] Sowing depth is an important factor affecting seed emergence time and crop yield. Under undulating terrain conditions, traditional seeders cannot adjust the sowing depth in real time according to the terrain. Sowing too deep will affect seed germination, while sowing too shallow will affect the seed's water absorption, ultimately affecting crop yield.

[0003] Traditional sowing depth control methods mainly include mechanical limit, pressure adjustment, soil moisture feedback adjustment and ultrasonic / laser ranging feedback adjustment. They mainly obtain information and indirectly control the sowing depth through a single point. Under conditions with undulating terrain, the sowing depth cannot be adjusted in real time with the terrain, and the stability of the sowing unit cannot be guaranteed, resulting in inconsistent sowing depth.

[0004] Therefore, there is an urgent need for a control device and method that can adjust the sowing depth in real time according to the undulating terrain conditions to solve the above-mentioned problems existing in the traditional control method, so as to achieve fixed-depth precision sowing, which is of great significance for ensuring grain production. Summary of the Invention

[0005] In order to address the shortcomings of the background technology, the present invention provides a full-chain closed-loop sowing depth control device and method based on image perception. It collects ground distance information based on a camera and can adaptively change the soil penetration depth of the furrowing disc under undulating terrain conditions, thereby achieving fixed-depth sowing and ensuring the stability of the sowing unit and the consistency of the sowing depth.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The ditching disc is fixedly mounted on the bottom of the frame and is located just in front of the depth limiting wheel. The controller is fixedly connected to the rear frame and is used for data processing and issuing instructions to the electric push rod to control its telescopic movement.

[0008] A full-chain closed-loop seeding depth control method based on image perception includes the following steps:

[0009] Step 1: Use the camera to measure the change of ground distance over time d(t);

[0010] Step 2: Obtain the speed v of the full-chain closed-loop seeding depth control device as the signal transmitted by the controller. At a certain moment, when the camera collects ground distance information, the corresponding distance at the deep-drilling wheel position is d1(t), and the corresponding distance at the furrowing disc position is d2(t). d1(t) and d2(t) satisfy the following relationship relative to the original distance d(t) measured by the camera:

[0011]

[0012]

[0013] Where Δl is the horizontal distance from the center of the trenching disc to the center of the depth-limiting wheel, l ek is the horizontal distance from the camera to the center of the trenching disk;

[0014] Step 3: Based on d1(t) and d2(t), the height difference d between the trenching disc and the depth-limiting wheel corresponding to time t is obtained. h (t), satisfying the following relationship:

[0015] d h (t) = d s +(d2(t)-d1(t))

[0016] Where, d s is the desired sowing depth;

[0017] When the ground is sunken, the depth of the trenching disc is increased by increasing the extension of the electric push rod to increase the lifting amount of the depth-limiting wheel; when the ground is convex, the depth of the trenching disc is reduced by reducing the extension of the electric push rod to reduce the lifting amount of the depth-limiting wheel.

[0018] Step 4: According to d h (t) and the geometric relationship of the vehicle body, the length l of the electric push rod at time t is obtained ab (t), complete the depth setting operation. When the planter is working on the undulating ground, the length of the electric push rod is obtained according to the following formula:

[0019]

[0020] Where h(t) is the height difference between the support point C of the depth-limiting arm and the center point D of the depth-limiting wheel at time t, h0 is the height difference between the support point C of the depth-limiting arm and the center point D of the depth-limiting wheel when the bottom end of the depth-limiting wheel and the bottom end of the trenching disc are on the same horizontal line, l cd is the distance from the depth limit arm fulcrum C to the depth limit wheel center D, lac is the distance between the hinge point A on the electric push rod and the fulcrum C of the depth limit arm, l bc is the distance between the lower hinge point B of the electric push rod and the fulcrum C of the depth limit arm, θ0 is the angle between the straight line AC and the vertical direction, θ1 is the angle between the straight line AC and the straight line BC, and θ2 is the angle between the straight line CD and the vertical direction.

[0021] Compared with existing technologies, the present invention has the following advantages: It uses a camera to collect ground distance information, and uses a controller to adjust the extension and retraction of the electric push rod in real time. This in turn presses or raises the depth-limiting arm to adjust the vertical movement of the depth-limiting wheel. This adaptively changes the depth of the furrowing disc into the soil under undulating terrain conditions, allowing the sowing depth to be adjusted in real time with the terrain. This achieves fixed-depth sowing, ensuring the stability of the sowing unit and consistent sowing depth, resolving the industry challenge of traditional sowing machinery's inability to meet real-time adjustments to the tillage depth under undulating terrain. Furthermore, the camera can acquire information over a wide range, eliminating the effects of surface stubble cover on ground distance measurement, enabling fixed-depth sowing in complex surfaces and resolving the problem of traditional sowing depth control being unable to avoid the effects of surface cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural diagram of the full-chain closed-loop sowing depth control device of the present invention;

[0023] Figure 2 It is a schematic diagram of the geometric relationship of the vehicle body in the full-chain closed-loop sowing depth control method of the present invention;

[0024] Figure 3 This is a schematic diagram of delayed acquisition of ground distance information in the full-chain closed-loop seeding depth control method of the present invention;

[0025] Figure 4 This is a schematic diagram of adjusting the furrowing disc and the depth-limiting wheel in the full-chain closed-loop sowing depth control method of the present invention;

[0026] Figure 5 d1(t), d2(t), and d(t) in the embodiment.

[0027] In the figure: 1-traction beam, 2-contact four-bar linkage, 3-camera, 4-positioning rod, 5-front frame, 6-frame, 7-electric push rod, 8-controller, 9-depth limiting arm, 10-depth limiting wheel, 11-ditching disc, 12-rear frame, 13-lifting power point, 14-connecting beam, 15-wheel frame, 16-covering wheel. DETAILED DESCRIPTION

[0028] The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] like Figure 1 As shown, a full-chain closed-loop sowing depth control device based on image perception includes a traction beam 1, a contour-matching four-bar linkage 2, a camera 3, a positioning rod 4, a front frame 5, a frame 6, an electric push rod 7, a controller 8, a depth-limiting arm 9, a depth-limiting wheel 10, a furrowing disc 11, a rear frame 12, a lifting power point 13, a connecting beam 14, a wheel frame 15, and a covering wheel 16.

[0030] A front frame 5 and a rear frame 12 are fixedly mounted at the front and rear ends of the top of the frame 6, respectively. A contoured four-bar linkage 2 is mounted in the middle of the front of the front frame 5. A traction beam 1 is fixedly mounted at the front end of the contoured four-bar linkage 2 for connection to a power tool. The traction beam 1 can be secured at its bottom end to a pre-set groove at the front end of the contoured four-bar linkage 2, and its top end is bolted to the front end of the contoured four-bar linkage 2, facilitating installation and removal of the traction beam 1 and the contoured four-bar linkage 2. The quadrilateral structure of the contoured four-bar linkage 2 allows for angle adjustment, allowing the traction beam 1 and the front frame 5 to shift height while maintaining a parallel position, thereby ensuring the frame 6's adaptability to uneven ground conditions as it moves with the power tool. A camera 3 is positioned in front of the top of the front frame 5 and connected to it via a positioning rod 4. The camera 3 is used to collect ground distance information and transmits it to the controller 8 in real time via a connecting harness. The depth-control arm 9 is arranged at an angle behind the bottom of the frame 6. The middle of the depth-control arm 9 is hinged to the frame 6 as a fulcrum. The lower end of the depth-control arm 9 is located in the middle of the bottom of the frame 6, and the upper end of the depth-control arm 9 extends upward from the rear end of the frame 6. The top of the rear upright frame 12 is hinged to the bottom end of the electric push rod 7. The telescopic end of the electric push rod 7 is tilted backward and hinged to the upper end of the depth-control arm 9, serving as the lifting power point 13. The depth-control wheel 10 comprises two wheels arranged coaxially and connected by an axle. The depth-control wheel 10 is arranged in the middle of the bottom of the frame 6 and is rotatably connected to the lower end of the depth-control arm 9. The trenching disc 11 is fixedly mounted on the bottom of the frame 6 and located directly in front of the depth-control wheels 10. The controller 8 is fixedly connected to the rear upright frame 12 for data processing and issuing commands to the electric push rod 7 to control its extension and retraction. The extension and retraction of the electric push rod 7 drives the depth-control arm 9 to adjust the height of the depth-control wheel 10, thereby controlling the depth of the trenching disc 11 into the ground to achieve trenching operations of varying depths. The wheel frame 15 is fixed to the rear of the frame 6 through the connecting beam 14, and the covering wheel 16 is installed at the bottom of the wheel frame 15 to gather soil into the ridge ditch to complete the ridge closing operation.

[0031] like Figures 1 to 4 As shown, a full-chain closed-loop seeding depth control method based on image perception includes the following steps:

[0032] When combined Figure 1 When the full-chain closed-loop sowing depth control device shown is working under an undulating ground condition, the distance between the camera 3 and the ground at different moments is measured by the camera 3. The ground position measured by the camera 3 at a certain moment will correspond to the positions of the furrowing disc 11 and the depth-limiting wheel 10 at different times as the power tool moves. According to the distance information between the furrowing disc 11 and the depth-limiting wheel 10 and the extension and contraction amount of the electric push rod 7, the up and down movement of the depth-limiting wheel 10 is adjusted by pressing down or lifting the depth-limiting arm 9 to achieve fixed-depth sowing. Specifically, the device includes:

[0033] Step 1: Obtain ground distance information, and measure the change of ground distance over time d(t) through camera 3;

[0034] Step 2: Obtain the speed v of the whole chain closed-loop sowing depth control device. The signal can be transmitted to the controller 8 through the communication bus equipped with the vehicle-mounted ground speed measuring radar, the wheel speed sensor or the power machine. At a certain moment, the camera 3 collects the ground distance information. The corresponding distance at the position of the deep-drilling wheel 10 is d1(t), and the corresponding distance at the position of the ditching disc 11 is d2(t). There is a delay between d1(t) and d2(t) relative to the original distance d(t) measured by the camera 3. Figure 3 As shown, the following relationship is satisfied:

[0035]

[0036]

[0037] Where Δl is the horizontal distance from the center of the trenching disc to the center of the depth-limiting wheel, l ek is the horizontal distance from the camera to the center of the trenching disk;

[0038] Step 3: Calculate the height difference d between the trenching disc 11 and the depth-limiting wheel 10 at time t based on d1(t) and d2(t). h (t), combined Figure 4 As shown, the following relationship is satisfied:

[0039] d h (t) = d s +(d2(t)-d1(t))

[0040] Where, d s is the desired sowing depth;

[0041] When the ground is sunken, the actual trenching depth should increase. Therefore, by increasing the extension of the electric push rod 7, the lifting amount of the depth-limiting wheel 10 is increased, so that the depth of the trenching disc 11 inserted into the soil is increased. When the ground is convex, the actual trenching depth should decrease. Therefore, by reducing the extension of the electric push rod 7, the lifting amount of the depth-limiting wheel 10 is reduced, so that the depth of the trenching disc 11 inserted into the soil is reduced.

[0042] Step 4: According to d h (t) and the geometric relationship between the vehicle body, the length of the electric push rod 7 at time t is obtained to complete the depth setting operation, which is as follows:

[0043] Combine Figure 2 As shown, the geometric relationship of the vehicle body is set as follows: the distance between the hinge point A on the electric push rod 7 and the support point C of the depth limit arm 9 is l ac The distance between the lower hinge point B of the electric push rod 7 and the support point C of the depth limit arm 9 is l bc The distance between the upper hinge point A and the lower hinge point B of the electric push rod 7 is l ab The distance from the fulcrum C of the depth limiting arm 9 to the center D of the depth limiting wheel 10 is l cd , θ0 is the angle between the straight line AC and the vertical direction, θ1 is the angle between the straight line AC and the straight line BC, θ2 is the angle between the straight line CD and the vertical direction, h0 is the height difference between the fulcrum C of the depth limiting arm 9 and the center D of the depth limiting wheel 10 when the bottom end of the depth limiting wheel 10 and the bottom end of the trenching disc 11 are on the same horizontal line, and h(t) is the height difference between the fulcrum C of the depth limiting arm 9 and the center D of the depth limiting wheel 10 at time t;

[0044] When the seeder is working on undulating ground, the length of the electric push rod 7 is calculated according to the following formula to meet the fixed-depth sowing requirements under different ground conditions:

[0045]

[0046] Where, l ab (t) is the length of the electric push rod at time t.

[0047] Example

[0048] Step 1: Combine the ground distance d(t) measured by camera 3 with the time Figure 5 As shown;

[0049] Step 2: In this embodiment, the speed of the whole machine is v = 1m / s. At a certain moment, when the camera 3 collects the ground distance information, the corresponding distance at the position of the deep-ditch wheel 10 is d1(t), and the corresponding distance at the position of the trenching disc 11 is d2(t). There is a delay between d1(t) and d2(t) relative to the original distance d(t) measured by the camera 3, and the following relationship is satisfied:

[0050]

[0051]

[0052] In this embodiment, the horizontal distance Δl from the center of the groove disc to the center of the depth-limiting wheel is 0.1 m, and the horizontal distance lek from the camera to the center of the groove disc is 1 m. Therefore, d1(t) = d(t-1.1), d2(t) = d(t-1), and d1(t) and d2(t) are also combined. Figure 5 As shown, at t = 2.95s, d1 = 0.92m, d2 = 0.93m are measured. Assuming the desired sowing depth d s 0.03m;

[0053] Step 3: Calculate the height difference d between the trenching disc 11 and the depth-limiting wheel 10 at time t based on d1(t) and d2(t). h (t), satisfying the following relationship:

[0054] d h (t) = d s +(d2(t)-d1(t))

[0055] In this embodiment, at time t=2.95s, the corresponding d h (t) is d ht＝2.95 =0.03+(0.93-0.92)=0.04m;

[0056] Step 4: When the planter is working on an undulating ground, the length of the electric push rod 7 is calculated according to the following formula:

[0057]

[0058] In this embodiment, the invariant h0=0.18m,l cd =0.25m,θ0=5°,l ac =0.46m,l bc =0.25m, the change over time at t=2.95s, the corresponding h(t) is h t＝2.95 , d h (t) is d ht＝2.95 =0.04m,l ab (t) is l abt＝2.95 , then:

[0059]

[0060] At t = 2.95s, the values ​​are:

[0061]

[0062] Therefore, the desired sowing depth d can be obtained at this time. s The length l of the corresponding electric push rod 7ab It is 0.36m.

[0063] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other configurations without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations coming within the meaning and range of equivalents of the claims are intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0064] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A full-chain closed-loop sowing depth control method based on image perception, wherein the device comprises a camera (3), a frame (6), an electric push rod (7), a controller (8), a depth-limiting arm (9), a depth-limiting wheel (10) and a furrowing disc (11), wherein a front stand (5) and a rear stand (12) are fixedly provided at the front and rear ends of the top of the frame (6), respectively, and the camera (3) is connected and positioned in front of the top of the front stand (5) through a positioning rod (4), and the camera (3) is used to collect ground distance information and transmit it to the controller (8) in real time, and the depth-limiting arm (9) is arranged obliquely at the rear of the bottom of the frame (6). The middle position of the depth-limiting arm (9) is hinged to the frame (6) as a fulcrum, the top of the rear stand (12) is hinged to the bottom end of the electric push rod (7), the telescopic end of the electric push rod (7) is tilted backward and hinged to the upper end of the depth-limiting arm (9), the depth-limiting wheel (10) is arranged at the middle position of the bottom of the frame (6) and is rotatably connected to the lower end of the depth-limiting arm (9), the ditching disc (11) is fixedly mounted on the bottom of the frame (6) and is located directly in front of the depth-limiting wheel (10), and the controller (8) is fixedly connected to the rear stand (12) for data processing and issuing instructions to the electric push rod (7) to control its telescopic movement; Its characteristics are: The control method comprises the following steps: Step 1: Measure the ground distance change d(t) with time through camera (3); Step 2: Obtain the speed v of the whole chain closed-loop sowing depth control device to transmit a signal to the controller (8). At a certain moment, when the camera (3) collects the ground distance information, the corresponding distance at the position of the deep-drilling wheel (10) is d1(t), and the corresponding distance at the position of the furrowing disc (11) is d2(t). d1(t) and d2(t) relative to the original measured distance d(t) of the camera (3) satisfy the following relationship: Where, is the horizontal distance from the center of the trenching disc to the center of the depth-limiting wheel. is the horizontal distance from the camera to the center of the trenching disk; Step 3: Calculate the height difference between the trenching disc (11) and the depth-limiting wheel (10) corresponding to time t based on d1(t) and d2(t) , satisfying the following relationship: Where, d s is the desired sowing depth; When the ground is sunken, the lifting amount of the depth-limiting wheel (10) is increased by increasing the extension of the electric push rod (7), thereby increasing the depth of the trenching disc (11) embedded in the soil; when the ground is convex, the lifting amount of the depth-limiting wheel (10) is reduced by reducing the extension of the electric push rod (7), thereby reducing the depth of the trenching disc (11) embedded in the soil; Step 4: According to The length of the electric push rod (7) at time t is obtained by the geometric relationship between the vehicle body and the vehicle body. , complete the depth setting operation. When the planter is working on an undulating ground, the length of the electric push rod (7) is obtained according to the following formula: Where, is the height difference between the depth limit arm fulcrum C and the depth limit wheel center D at time t, It is the height difference between the depth limit arm fulcrum C and the depth limit wheel center D when the bottom of the depth limit wheel and the bottom of the trenching disc are on the same horizontal line. is the distance from the depth limit arm fulcrum C to the depth limit wheel center D, is the distance between the hinge point A on the electric push rod and the fulcrum C of the depth limit arm, is the distance between the lower hinge point B of the electric push rod and the fulcrum C of the depth limit arm, is the angle between line AC and the vertical direction, is the angle between line AC and line BC, is the angle between line CD and the vertical direction.

2. The full-chain closed-loop seeding depth control method based on image perception according to claim 1, characterized in that: A contour-copying four-link mechanism (2) is assembled and arranged at the middle position in front of the front stand (5), and a traction beam (1) is fixedly arranged at the front end of the contour-copying four-link mechanism (2) and connected to the power machine.

3. The full-chain closed-loop seeding depth control method based on image perception according to claim 1 or 2, characterized in that: A wheel frame (15) is installed at the rear of the frame (6) via a connecting beam (14), and a soil covering wheel (16) is provided at the bottom of the wheel frame (15).

4. The full-chain closed-loop seeding depth control method based on image perception according to claim 1 is characterized by: The speed v transmits a signal to the controller (8) via a communication bus equipped with a vehicle-mounted ground speed measuring radar, a wheel speed sensor or a power tool.

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