Seed external damage detecting and removing device based on machine vision

Abstract

The invention discloses a seed external damage detection and removal device based on machine vision. The seed external damage detection and removal device comprises a seed conveying module, a seed detection module and a seed removal and recovery module, the seed conveying module comprises a funnel, a conveying turntable, a seed guide pipe, a dispersion baffle and a guide baffle. The seed detection module comprises a camera, a soft light cover, a detection rotating disc, an LED annular light source and a background plate. The seed removing and recycling module comprises a telescopic mechanical arm, a removing shifting piece, a rotating support and a collecting barrel. The three modules are respectively a conveying module, a detection module and a removal and recovery module from top to bottom. Seeds enter from a funnel of the conveying module, pass through a dispersion baffle, a guide baffle and a seed guide pipe to realize a single-grain conveying function, and then are conveyed to the detection turntable through the seed guide pipe, and two cameras arranged above and below the detection turntable are used for carrying out double-sided image acquisition and judging whether the seeds are qualified or not; finally, the seeds are fed into a collecting barrel through a telescopic mechanical arm of the removing and recycling module.

Description

Technical Field

[0001] This technical solution relates to a machine vision-based seed external damage detection and classification device, belonging to the field of seed treatment technology in agricultural machinery. Background Technology

[0002] Corn is one of my country's major economic crops, and seed quality is an important factor in producing high-quality and high-yield corn.

[0003] Agricultural product quality inspection mainly includes the detection and identification of parameters such as defects, size, and maturity. Traditional techniques relied primarily on human visual identification and manual selection. Later, a combination of human visual identification and machine screening was adopted. However, this approach has significant drawbacks. Human visual identification is highly subjective, inefficient, and fatigue from prolonged manual inspection can lead to detection errors, with relatively large random errors. Machine vision technology has developed rapidly and is widely used in non-destructive testing of agricultural products. For non-destructive testing of seeds, the main challenge lies in efficiently automating the process to ensure that small seeds are reliably transferred from the feed end to the image acquisition system, captured, and properly sorted after inspection. This is a difficult task to achieve. Summary of the Invention

[0004] To address the aforementioned technical challenges, this invention proposes an innovative solution. This solution employs machine vision technology to inspect and sort seeds. In large-scale, repetitive production activities, it avoids mechanical damage to seeds during the inspection process, effectively improving production efficiency and automation.

[0005] The detection module of this device is equipped with two cameras to detect the damage on the front and back of the seeds respectively. At the same time, a telescopic robotic arm is deployed to collect and remove the seeds, which improves the efficiency and automation of the detection. It also avoids the detection error caused by fatigue due to excessive time in manual detection and reduces labor costs.

[0006] Specifically:

[0007] A machine vision-based seed external damage detection and classification device includes a delivery module, a detection module, and a rejection module connected to the same support structure (i.e., the outer support of the device) and sequentially connected through a seed delivery pipe.

[0008] A. The conveying module includes a working chamber, a funnel, a conveying turntable, a dispersing baffle, a guiding baffle, a seed guide tube, and a conveying turntable rotation assembly; the conveying turntable is horizontal;

[0009] The funnel is fixed above the working chamber, and the projection of the funnel's outlet is on the top surface of the conveyor turntable;

[0010] The conveyor turntable is located on the bottom surface of the working chamber and rotates under the drive of the conveyor turntable rotating assembly. The direction of rotation of the conveyor turntable is defined as forward. The gap between the edge of the conveyor turntable and the side wall of the working chamber is smaller than the size of a single seed.

[0011] The funnel, dispersion baffle, and guide baffle are all fixed in the working chamber and above the conveyor turntable;

[0012] The span of the dispersing baffle extends from the center to the edge of the conveyor turntable; multiple separating plates are vertically connected to the bottom edge of the dispersing baffle, and the distance between the bottom edge of the separating plates and the top surface of the conveyor turntable is less than the thickness of a single seed; adjacent separating plates form a channel for the seeds to pass through, and the channel points forward.

[0013] There is a seed dispensing channel on the edge of the conveyor turntable, which is far from the outlet of the funnel. The seed dispensing channel is formed by a thin-walled baffle and the side wall of the working chamber corresponding to its position. The distance between the bottom edge of the thin-walled baffle and the top surface of the conveyor turntable is less than the thickness of a single seed.

[0014] A seed outlet is opened at the bottom of the seed dispensing channel, and only one seed can pass through at the end of the seed dispensing channel; a sensor is installed at the seed outlet.

[0015] The specific structure consists of three levers at the end of the seed metering channel, which respectively form the two side walls and the top surface of the end of the seed metering channel. The space enclosed by the three levers and the bottom surface of the seed metering channel allows only one seed to pass through. The main body of the sensor installed at the seed metering port is directly above the seed metering port, with the sensing end of the sensor facing the seed metering port. These three levers are used to adjust the size of the seed metering channel so that the narrowest part of the seed metering channel allows only one seed to pass through.

[0016] A guide baffle is connected to the entrance end of the seed metering channel. The guide baffle is vertical, and the distance between the bottom edge of the guide baffle and the top surface of the conveying turntable is less than the thickness of a single seed. The first end of the guide baffle is connected to the inner side of the dispersing baffle, and the second end of the guide baffle is connected to the entrance end of the seed metering channel, with the second end of the guide baffle in front of the first end.

[0017] B. The detection module is located below the conveying module; the detection module includes: an image acquisition component, a detection turntable, a background plate, and a detection turntable rotation component;

[0018] The detection turntable is horizontal and rotates under the drive of the detection turntable rotation assembly;

[0019] There are multiple through holes around the center on the disc of the detection turntable. The surface of each through hole is covered with optical glass to form a detection area. The top surface of the optical glass and the top surface of the disc are on the same circular surface.

[0020] The image acquisition components are divided into two sets, which are distributed on the upper and lower sides of the detection turntable. The lenses of the two sets of image acquisition components are vertically facing two adjacent detection areas, one above and one below. A background plate is installed on the side of the lens opposite to the detection turntable. A diffuser with a uniform light source is installed on the lens.

[0021] The seed delivery tube connects the seed outlet and the detection area;

[0022] When the sensor at the seed outlet detects that there are seeds at the seed outlet, the conveyor turntable rotation assembly drives the conveyor turntable and the detection turntable to rotate synchronously.

[0023] C. The rejection module includes: a guide chute, a telescopic robotic arm, and a rejection lever;

[0024] There are two guide slots located on the outer edge of the detection turntable, and the inlet height of the guide slots is no higher than the top surface of the detection turntable; the positions of the two guide slots correspond to a set of two adjacent detection areas; there is a seed collection device below the outlet of the guide slots.

[0025] The telescopic robotic arm is controlled to rotate between two guide grooves, and the rejection plate is installed at the front end of the telescopic robotic arm. When the telescopic robotic arm is retracted, the rejection plate leaves the surface of the detection turntable. When the telescopic robotic arm is extended, it rotates with the telescopic robotic arm, and the coverage area of ​​the rejection plate covers two adjacent detection areas, and the distance between the bottom surface of the rejection plate and the detection turntable is less than the thickness of a seed.

[0026] Furthermore, in the conveying module, the top surface of the conveying turntable is rough.

[0027] Furthermore, the support structure is an external support; the main body of the external support is a cubic frame, with transparent panels installed on the top and sides of the frame;

[0028] The conveyor turntable, detection module, and rejection module are installed inside the cavity of the outer support; the funnel is installed on the top of the outer support, and the outlet of the funnel is on the top surface of the outer support.

[0029] The side of the outer support is equipped with a door that can be opened and closed, and the position of the door corresponds to the position of the collection device.

[0030] Furthermore, in the conveying module, the outlet of the funnel is connected to an inner baffle for the initial dispersion of seeds; there are multiple parallel inner baffles, and adjacent inner baffles form seed channels, each seed channel having the same width.

[0031] Furthermore, the seed guide tube is divided into three sections: the seed inlet section and the seed outlet section are vertical pipes, and there is an inclined groove between the seed inlet section and the seed outlet section; the inlet of the seed inlet section is fixedly connected to the seed discharge port, and the projection of the seed outlet section is on the detection area of ​​the detection turntable.

[0032] The operational steps of the machine vision-based seed external damage detection and rejection device include:

[0033] S1) Action 1:

[0034] The device is started, and the conveyor turntable rotates at a constant speed. The detection turntable is measured to be one stroke every n degrees of rotation. The motion mode is intermittent rotation, and one stroke is completed every time t.

[0035] S2) Action Two:

[0036] Seeds enter through a funnel, are initially dispersed by an inner baffle at the bottom of the funnel, and then enter the conveyor turntable.

[0037] The seeds are further dispersed as they pass through the dispersing baffles on the conveyor turntable;

[0038] Guided by the guide baffle, the seeds flow to the edge of the conveyor turntable and enter the seed dispensing channel;

[0039] S3) Action Three:

[0040] After the sensor at the seed dispensing port of the seed dispensing channel detects the seeds, the conveyor turntable begins to dispense seeds intermittently at a frequency of t / seed, synchronized with the rotation of the detection turntable;

[0041] Seeds fall into the detection area on the detection turntable through the seed guide tube. The detection turntable rotates clockwise by n° to move a single seed under the downward-facing lens for image acquisition of the seed's front side. After acquisition, the detection turntable rotates counterclockwise by n° to reach the upward-facing lens for image acquisition of the seed's back side. The images of the seed's front and back sides are sent to a computer equipped with detection and recognition algorithms for analysis, and a judgment is made on whether the seed is intact.

[0042] S4) Action Four:

[0043] After the judgment is completed, the detection turntable continues to rotate to move the seed to the rejection module position;

[0044] If the judgment result is "qualified", the detection turntable rotates, the seeds reach the guide chute corresponding to the qualified seed collection device, the telescopic robotic arm extends and rotates, driving the rejection pick to send the qualified seeds into the guide chute and fall into the qualified seed collection device.

[0045] If the judgment result is "unqualified", the detection turntable will continue to rotate until it reaches the guide chute corresponding to the unqualified seed collection device. The telescopic robotic arm drives the rejection pick to send the seed into the guide chute and fall into the unqualified seed collection device.

[0046] S5) Action Five:

[0047] When the seed metering sensor on the conveyor turntable does not detect seeds, the conveyor turntable continues to rotate at a constant speed until the sensor is triggered, at which point it begins to rotate intermittently in sync with the detection turntable.

[0048] Beneficial effects and principles:

[0049] 1) Non-contact, non-destructive testing technology is used to detect external damage to seeds and sort and remove them, realizing the integration of double-sided detection and sorting of seeds.

[0050] 2) In this device, the seed conveying method is different from the traditional conveyor belt form. A turntable is used to realize the conveying and detection, which can effectively convey the seeds into different work stations to complete different processes. The conveying turntable and the detection turntable effectively reduce the size of the device.

[0051] 3) The seed rejection module integrates seed recycling and rejection through the movement of a telescopic robotic arm. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the structure of the seed external damage detection and rejection device;

[0053] Figure 2 This is a schematic diagram (perspective) of the conveyor module structure;

[0054] Figure 3 This is a schematic diagram of the detection module structure;

[0055] Figure 4 This is a schematic diagram of the module structure after elimination;

[0056] Figure 5 This is a simplified schematic diagram of the external support structure;

[0057] Figure 6(a) is a simplified schematic diagram of the funnel structure; Figure 6(b) is a simplified schematic diagram of the funnel structure (perspective);

[0058] Figure 7 This is a schematic diagram of the structure of the dispersion baffle 103;

[0059] Figure 8 This is a simplified schematic diagram of the guide baffle 107 structure;

[0060] Figure 9(a) is a simplified schematic diagram of the conveyor turntable 102 (top view);

[0061] Figure 9(b) is a simplified schematic diagram (perspective) of the conveyor turntable 102.

[0062] Figure 10 Here is a simplified schematic diagram of the seed delivery tube 106.

[0063] Figure 11 A simplified schematic diagram of the 204 turntable structure for testing;

[0064] Figure 12 This is a simplified schematic diagram of the image acquisition system structure;

[0065] Figure 13 To remove the simplified structural diagram of the 307 paddle shifter;

[0066] Figure 14 This is a simplified schematic diagram of the telescopic robotic arm 302.

[0067] Figure 15 A simplified schematic diagram of the guide chute 301 structure;

[0068] Figure 16 A simplified schematic diagram of the conveyor turntable transmission mechanism;

[0069] Figure 17 A simplified schematic diagram of the turntable transmission mechanism for testing;

[0070] Figure 18 A simplified schematic diagram of the transmission structure of the elimination device;

[0071] In the picture:

[0072] 1 is the conveying module, 2 is the detection module, 3 is the rejection module, and 4 is the external support.

[0073] 101 is the funnel, 102 is the conveyor turntable, 103 is the dispersing baffle, 104 is the conveyor transmission gear set, 105 is the conveyor motor, 106 is the seed guide tube, 107 is the guide baffle, 108 is the conveyor driven gear, 109 is the conveyor driving gear, 110 is the conveyor motor, 111 is the fixed shaft support, 112 is the seed dispensing port, 113 is the sensor, 114 is the working chamber, 115 is the inner baffle, 116 is the seed dispensing channel, 117 is the thin-walled baffle, and 118 is the (three) levers of the seed dispensing channel;

[0074] 201 is the camera stand, 202 is the camera, 203 is the backdrop, 204 is the detection turntable, 205 is the detection transmission gear set, 206 is the detection motor, 207 is the diffuser, 208 is the detection driven gear, 209 is the detection driving gear, and 210 is the detection motor.

[0075] 301 is the guide chute, 302 is the telescopic robotic arm, 303 is the electric push rod, 304 is the rejection motor, 305 is the rejection transmission gear set, 306 is the collecting device, 307 is the rejection lever; 308 is the gear rack, 309 is the electric push rod, 310 is the transmission gear set, and 311 is the rejection motor.

[0076] 401 is the crossbeam. Detailed Implementation

[0077] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0078] This example of a machine vision-based seed (in this case, corn seeds) external damage detection and rejection device consists of three core modules: a conveying module, a detection module, and a rejection module. The conveying module ensures a stable feed of seeds from the device to the detection module, while allowing for orderly, single-seed detection without stacking. The detection module acquires images from both sides of the seeds. The rejection module collects qualified and intact corn seeds and rejects unqualified ones.

[0079] Specifically, in this example, refer to Figure 1 A machine vision-based seed external damage detection and classification device includes a conveying module 1, a detection module 2, and a rejection module 3; the conveying module, the detection module, and the rejection module are fixed on the same support structure, namely the outer support 4 of the device.

[0080] Further reference Figure 2 The conveying module 1 consists of a funnel 101, a conveying turntable 102, a dispersing baffle 103, a guiding baffle 107, a seed guide tube 106, a conveying transmission gear set 104, and a conveying motor 110.

[0081] The funnel, the dispersing baffle, and the guide baffle are all fixed above the conveying turntable. The conveying turntable and the motor are fixed to the fixed shaft bracket 111 by bolts. The lower part of the conveying turntable is fixed to the conveying driven gear 108 and forms a gear transmission with the conveying driving gear 109 on the motor. The seed guide tube is fixed at the seed discharge port 112 of the conveying turntable. A sensor 113 is provided at the seed discharge port for detecting seeds.

[0082] Referring to Figures 6(a) and 6(b), the funnel is fixed to the top surface of the working chamber 114 by four small cylinders at the bottom for positioning. An inner baffle 115 is provided at the lower outlet of the funnel to disperse the seeds to a certain extent.

[0083] The upper part of the funnel is shaped like an inverted trapezoidal platform, 80mm high. The upper opening is a rectangle with a long side of 208mm, a short side of 68mm, and a wall thickness of 4mm. The lower opening is a rectangle with a long side of 104mm, a short side of 34mm, and a wall thickness of 2mm. Both the upper and lower openings extend upwards with square tubes 10mm high. The lower part is an oblique parallelepiped, 20mm high, with both the upper and lower openings being rectangles with a long side of 104mm and a short side of 34mm, and a wall thickness of 2mm. Inside, four inner baffles are evenly distributed along the long side (seed flow direction). The four corners of the lower part are cylinders 10mm high and 4mm in diameter. The inner baffles serve to initially disperse the seeds placed in the funnel, and the four cylinders serve to fix the funnel on the conveyor turntable.

[0084] refer to Figure 7The mounting plate on the side of the dispersing baffle has two screw holes for fixing to the fixed axis bracket 111. There are six paddles at the bottom with a minimum spacing of 20mm, a maximum spacing of 46mm, and a height of 15mm. The dispersing baffle mainly uses the six paddles at the bottom to further disperse the seeds.

[0085] refer to Figure 8 The guide baffle is arc-shaped, with a mounting plate on its side featuring two screw holes. The mounting plate secures the guide baffle to the fixed-axis bracket 111. After installation, the distance between the tip of the guide baffle and the edge wall of the conveyor turntable is 13-14 mm. Driven by the rotation of the conveyor turntable, the corn seeds flow towards the edge of the turntable via the arc-shaped guide baffle. Controlling the distance between the baffle tip and the edge wall ensures that each seed passes through individually and enters the seed dispensing channel. The 13-14 mm distance between the guide baffle tip and the edge wall of the conveyor turntable conforms to the length and width characteristics of corn seeds, ensuring that the vast majority of corn seeds can pass through individually and smoothly.

[0086] The center of the conveyor turntable has a mounting hole for the fixed-axis bracket 111, and the two are connected by a bearing structure. The mounting plates on both sides of the working chamber 114 have threaded holes for fixing with the outer bracket 4. Regarding the design of the conveyor turntable diameter, it is considered that if the diameter of the turntable is too large, the seeds will rotate on the turntable for too long, and the corn seeds will float and bounce. If the diameter of the turntable is too small, the seed population will directly enter the seed dispensing channel 116 at the edge of the conveyor turntable without effective guidance from the guide plate. At this time, the seed movement is in a disordered state. Based on the overall size requirements, the diameter of the conveyor turntable is set to 346mm. The seed dispensing channel is composed of a thin-walled baffle 117 with a radius of 157mm and the side wall of the working chamber 114. The width of the seed dispensing channel is 16mm.

[0087] refer to Figure 2 At the end of the seed metering channel, three levers control the single-seed delivery. These three levers (118) form the two side walls and the top surface of the seed metering channel's end, respectively. The space enclosed by the three levers and the bottom surface of the seed metering channel allows only one seed to pass through at a time. The three levers ensure that the size of the seed metering channel's end is just right for a single seed to pass through. Taking corn seeds as an example, the narrowest part of the seed metering channel, enclosed by the three levers, has a width of 14mm and a height of 10mm, just enough for a single corn seed to pass through. The sensor body is installed directly above the seed metering opening, with the sensor's sensing end facing the opening.

[0088] At the end of the seed metering channel, three levers 118 control the single-seed delivery of corn. The seed metering port 112 is the narrowest point between the three levers. The sensor 113 is a BC3-M12-AP6X-H1141 capacitive sensor, which uses a wide DC power supply range of 10-30VDC and has a three-wire PNP normally open output.

[0089] refer to Figure 10 The seed guide tube is divided into three sections: the seed inlet and the seed outlet are vertical pipes. The seed inlet has an inner diameter of 16mm and an outer diameter of 20mm. The seed inlet is welded to the seed discharge port of the conveying turntable. According to the test results of the sliding friction angle of corn seeds, when the horizontal angle satisfies ∠θ>27.6°, the corn seeds can slide normally along the inclined groove made of 203 grade stainless steel plate. Therefore, the horizontal installation angle θ of the inclined groove is designed to be 30°, the horizontal projection length is 198mm, the vertical projection height is 123mm, the inner width of the seed guide tube is 15mm, the outer width is 20mm, the inner width of the seed outlet is 10mm, the outer width is 15mm, and the vertical height outside the seed outlet is 20mm. This allows the corn seeds to enter the seed guide tube after being discharged from the seed discharge port of the conveying turntable, slide down the inclined groove under their own gravity, and fall into the detection area of ​​the detection turntable under the guidance of the seed outlet of the seed guide tube.

[0090] refer to Figure 16 The bottom of the conveyor turntable is fixed to the driven gear, and the conveyor motor is fixed on the fixed-axis bracket 111. Driven by the conveyor (stepper) motor 105, the conveyor turntable rotates counterclockwise through gear transmission. The conveyor drive gear 109 in the transmission gear set of the conveyor module has a module of 2, 12 teeth, and a diameter of 24mm; the conveyor driven gear 108 has a module of 2, 48 teeth, and a diameter of 96mm, with a transmission ratio of 4:1. The conveyor motor is an AZM46AC-FC7.2DA+AZD-C+CC030VZF type motor; the power input voltage of this motor is 200-240V, the power input current is 1.0A, the speed range is 0-416r / min, and the weight is 0.79kg.

[0091] Further reference Figure 3 The detection module consists of a camera bracket 201, a camera 202, a background plate 203, a detection turntable 204, a detection transmission gear set 205, a detection motor 206, and a diffuser 207.

[0092] See again Figure 11The detection turntable is fixed to the fixed-axis bracket 111 by bearings. Six detection areas are evenly distributed on the turntable. These areas are made of completely transparent optical glass, fixed to the turntable by solvent bonding, to facilitate image acquisition by the upper and lower cameras. Corn seeds fall into the detection areas of the turntable through the seed guide tube 106. The rotating turntable sequentially transports the seeds to the front image acquisition station, the back image acquisition station, the rejection station for unqualified seeds, or the collection station for qualified seeds. The detection turntable has a diameter of 350mm, the detection area diameter is 63mm, the central angle between adjacent detection areas is 60°, and the distance from the center of the detection area to the center of the turntable is 118mm. The bottom of the turntable is fixed to the driven gear 208. The detection motor 210 is fixed to the fixed-axis bracket 111 and drives the turntable to rotate via gear transmission under the drive of the detection (stepper) motor.

[0093] The camera used is the Daheng Mercury MER-500-7UC-L color industrial camera, with a maximum resolution of 2592×1944, a frame rate of 7fps at the maximum resolution, a focal length of 4mm, and an angle of view of 40°.

[0094] refer to Figure 12 The camera is fixed to the fixed-axis bracket 111 by a camera mount. The camera mount is equipped with threaded holes, and the position of the camera mount is fixed and adjusted by adjusting the tightness of the bolts and nuts. Two cameras are arranged above and below two adjacent detection areas of the detection turntable, respectively. The optical axis of the lens is perpendicular to the detection turntable and located in the center of the detection area. A diffuser 207 with a ring light source is mounted on the camera lens. A background plate 203 is mounted on the other side of the detection area and fixed to the fixed-axis bracket 111. The overall surface of the background plate is a low-reflectivity matte black. The image acquisition area is equipped with a sensor to monitor the seed position (in practice, if an algorithm that can identify the seed position in the image is used, the sensor is not required to detect the seed position).

[0095] The cameras at the top and bottom are a front image acquisition camera and a back image acquisition camera, respectively. The front image acquisition camera is mounted directly above the corresponding detection area, with the lower surface of its lens 32mm from the upper surface of the detection turntable. The background plate is mounted 15mm below the detection turntable. The back image acquisition camera is mounted below the corresponding detection area, with the upper surface of its lens 32mm from the upper surface of the detection turntable. The background plate is mounted 15mm above the upper surface of the detection turntable. A light shield is mounted in the middle of the camera body, and an LED ring light source is mounted on the diffuser, 12mm from the lens surface.

[0096] refer to Figure 17The detection transmission gear set 205 of the detection module has a detection drive gear 209 with a module of 2, 12 teeth, and a diameter of 24mm, and a detection driven gear 208 with a module of 2, 48 teeth, and a diameter of 96mm. The transmission ratio is 4:1. The detection motor 210 is an AZM46AC-FC7.2DA+AZD-C+CC030VZF type motor. The power input voltage of this motor is 200-240V, the power input current is 1.0A, the speed range is 0-300r / min, and the weight is 0.79kg.

[0097] Further reference Figure 4 The rejection module consists of a guide chute 301, a telescopic robotic arm 302, an electric push rod 303, a rejection motor 304, a rejection transmission gear set 305, a collection device 306, and a rejection lever 307; the rejection lever is installed at the front end of the telescopic robotic arm, and the robotic arm is driven by the electric push rod and installed on a rotating bracket driven by gears.

[0098] refer to Figure 13 The tail of the paddle is made up of two parallel mounting plates with two threaded holes for connecting and fixing to the telescopic robotic arm. The front end of the paddle is a tapered paddle with a length of 63mm and a thickness of 16mm.

[0099] refer to Figure 14 The telescopic robotic arm is hinged using a parallelogram principle and driven by a gear and rack transmission, with an electric push rod to complete the extension and retraction process. The entire robotic arm is fixed to the outer support of the device, and its rotation is completed by the motor and gears on the base. The telescopic robotic arm has two degrees of freedom, a maximum working radius of 300mm, and a rotation angle of -90° to 90°. The robotic arm, including the power unit, weighs 2kg. The extension and retraction of the robotic arm is to prevent the rejection plate from being on the detection turntable for a long time, interfering with the entire detection cycle. When the corn seeds arrive at the collection station, if they are qualified seeds, the telescopic robotic arm extends and rotates counterclockwise to push the seeds into the collection bucket (collection device 306). If they are unqualified seeds, the arm extends again and rotates clockwise to push the seeds to complete the rejection work when they arrive at the rejection station. After collection or rejection is completed, the robotic arm will retract to the initial position, waiting for the next work cycle.

[0100] refer to Figure 18The telescopic robotic arm's rack is designed with a module of 1 and a length of 30mm, and the mating gear has a module of 1 and 10 teeth. The telescopic robotic arm's electric actuator is a Jiechang JCS-D-20-300-24V type electric actuator; this electric actuator has a rated thrust of 20N, a stroke of 300mm, a voltage of 24V, and a speed of 600m / s. The rejection module's rejection transmission gear set is designed with a rejection driving gear having a module of 1 and 20 teeth, and a rejection driven gear having a module of 1 and 40 teeth, with a transmission ratio of 2:1. The rejection motor is an AZM46AC-FC20DA+AZD-C+CC030VZF type motor; this motor has a power input voltage of 200-240V, a power input current of 1.0A, a speed range of 0-150r / min, and a weight of 0.79kg.

[0101] refer to Figure 15 The main function of the guide chute is to prevent corn seeds from deviating too much when the robotic arm moves and failing to fall accurately into the collection bucket (collection device). The guide chute is fixed on the fixed axis bracket 11, and the guide part is in close contact with the detection turntable, directly facing the collection and rejection station.

[0102] The collection device consists of a collection bucket and a rejection bucket, which are responsible for collecting qualified corn seeds and rejecting unqualified seeds. The collection device is placed directly below the guide chute to ensure that the seeds fall accurately into the collection device.

[0103] Further reference Figure 5 The outer support 4 of the device is a cubic frame with an overall length of 550mm, width of 510mm, and height of 669mm. The top crossbeam 401 is used to fix the conveyor turntable and the fixed-axis support 111 of the entire device. The outer support serves to prevent dust and other foreign objects from falling into the device and interfering with the detection, isolate some of the device's noise, and allow observation of the actual situation of the corn seed detection process through the acrylic plate. Except for the bottom surface, the outside of the device is equipped with transparent acrylic plates, which are fixed to the outer support with screws. A door connected by hinges is installed in the direction of the collection device. Lockable casters are installed at the four corners of the bottom of the outer support, improving the overall mobility of the device.

[0104] The seed detection and removal method using a seed external damage detection and removal device includes the following steps:

[0105] S1) Action 1:

[0106] When the device is started, the conveyor turntable rotates at a constant speed under the drive of the stepper motor. The detection turntable completes one stroke every 60°, and the movement mode is intermittent rotation, completing one stroke every 2 seconds.

[0107] S2) Action Two:

[0108] Corn seeds enter through a funnel, are initially dispersed by the inner baffle of the funnel, and then enter the conveyor turntable. As the conveyor turntable rotates, the corn seeds are further dispersed by the dispersing baffle, and then guided by the arc-shaped guide baffle, the corn seeds flow to the seed dispensing channel at the edge of the conveyor turntable. The control of the baffle tip and the width of the seed dispensing channel ensures that the corn seeds pass through individually.

[0109] S3) Action Three:

[0110] After the sensor at the seed dispensing port detects corn seeds, the conveyor turntable begins to dispense seeds intermittently at a frequency of 2 seconds per seed, synchronized with the rotation of the detection turntable.

[0111] Corn seeds fall into the detection area through a seed guide tube. The detection (stepper) motor drives the detection turntable to rotate through a transmission gear set. The detection turntable rotates 60° counterclockwise to move a single corn seed to the front image acquisition area for front image acquisition. After acquisition, the detection turntable continues to rotate 60° counterclockwise to reach the back image acquisition area for back image acquisition. After both sides are acquired, the images are processed and analyzed by a computer to determine whether the seed is intact.

[0112] S4) Action Four:

[0113] After the judgment is completed, the detection turntable continues to rotate 120° to move the seeds to the rejection module. If the judgment result is "qualified", the telescopic robotic arm of the rejection module will extend under the drive of the electric push rod. Then, the rejection (stepper) motor controls the robotic arm to rotate counterclockwise through gear transmission. Under the action of the rejection pick, the seeds are sent into the collection bin of qualified seeds. If the judgment result is "unqualified", the detection turntable will continue to rotate 60° to enter the next rejection station. The telescopic robotic arm will extend under the drive of the electric push rod. Then, the rejection (stepper) motor controls the robotic arm to rotate clockwise through gear transmission. Under the action of the rejection pick, the seeds are sent into the collection bin of unqualified seeds, completing the seed rejection and recycling work.

[0114] S5) Action Five:

[0115] When the seed dispensing sensor of the conveying module does not detect corn seeds, the conveying turntable will resume uniform rotation until the sensor is triggered, at which point it will begin intermittent rotation synchronized with the detection turntable and perform action three again.

[0116] Referring to the attached diagram, when this device is used for corn seeds, the corn seeds enter from the funnel 101, are initially dispersed by the baffle below the funnel, and enter the conveying turntable 102. The conveying turntable rotates at a constant speed, and the corn seeds are driven by the turntable to be dispersed again by the dispersing baffle 103. Then, the seeds are conveyed individually by the guide baffle 107 and enter the seed discharging channel 116. At the end of the seed discharging channel, there are three control levers 118 to control the individual conveying of corn seeds into the seed guide tube 106. In the seed guide tube, the corn seeds slide down normally due to their own gravity and enter the detection module.

[0117] When the sensor at the seed dispensing port detects corn seeds, the conveyor turntable changes from rotating at a constant speed to rotating synchronously with the detection turntable, and the conveying module starts dispensing seeds intermittently at a frequency of 2 seconds per seed.

[0118] The detection turntable 204 rotates intermittently, completing one stroke every 60°, with each stroke lasting 2 seconds. Corn seeds falling into the detection area of ​​the turntable are driven by its rotation, first rotating 60° counterclockwise to enter the front image acquisition station, then another 60° counterclockwise to enter the back image acquisition station, and finally another 120° counterclockwise to enter the collection station. If the computer processes the image and determines the seed is qualified, the telescopic robotic arm 302 extends and rotates counterclockwise, causing the rejection lever 307 to guide the corn seed through the guide chute 301 into the collection bin. If the computer determines the seed is unqualified, the telescopic robotic arm 302 will extend and rotate clockwise after the seed rotates counterclockwise again to enter the rejection area, causing the rejection lever 307 to guide the corn seed through the guide chute 301 into the rejection bin.

Claims

1. A machine vision-based seed external damage detection and rejection device, characterized in that: It includes a delivery module, a detection module, and a rejection module connected to the same support structure and sequentially connected through a seed delivery pipe; A. The conveying module includes a working chamber, a funnel, a conveying turntable, a dispersing baffle, a guiding baffle, a seed guide tube, and a conveying turntable rotation assembly; the conveying turntable is horizontal; The funnel is fixed above the working chamber, and the projection of the funnel's outlet is on the top surface of the conveyor turntable; The conveyor turntable is located on the bottom surface of the working chamber and rotates under the drive of the conveyor turntable rotating assembly. The direction of rotation of the conveyor turntable is defined as forward. The gap between the edge of the conveyor turntable and the side wall of the working chamber is smaller than the size of a single seed. The funnel, dispersion baffle, and guide baffle are all fixed in the working chamber and above the conveyor turntable; The span of the dispersing baffle extends from the center to the edge of the conveyor turntable; multiple separating plates are vertically connected to the bottom edge of the dispersing baffle, and the distance between the bottom edge of the separating plates and the top surface of the conveyor turntable is less than the thickness of a single seed; adjacent separating plates form a channel for the seeds to pass through, and the channel points forward. There is a seed dispensing channel on the edge of the conveyor turntable, which is far from the outlet of the funnel. The seed dispensing channel is surrounded by a thin-walled baffle and the side wall of the working chamber at its corresponding position. The distance between the bottom edge of the thin-walled baffle and the top surface of the conveyor turntable is less than the thickness of a single seed. A seed dispensing port is opened on the bottom surface at the end of the seed dispensing channel, and only one seed is allowed to pass through at the end of the seed dispensing channel. A sensor is installed at the seed dispensing port. A guide baffle is connected to the entrance end of the seed metering channel. The guide baffle is vertical, and the distance between the bottom edge of the guide baffle and the top surface of the conveying turntable is less than the thickness of a single seed. The first end of the guide baffle is connected to the inner side of the dispersing baffle, and the second end of the guide baffle is connected to the entrance end of the seed metering channel, with the second end of the guide baffle in front of the first end. B. The detection module is located below the conveying module; the detection module includes: an image acquisition component, a detection turntable, a background plate, and a detection turntable rotation component; The detection turntable is horizontal and rotates under the drive of the detection turntable rotation assembly; There are multiple through holes around the center on the disc of the detection turntable. The surface of each through hole is covered with optical glass to form a detection area. The top surface of the optical glass and the top surface of the disc are on the same circular surface. The image acquisition components are divided into two sets, which are distributed on the upper and lower sides of the detection turntable. The lenses of the two sets of image acquisition components are vertically facing two adjacent detection areas, one above and one below. A background plate is installed on the side of the lens opposite to the detection turntable. A diffuser with a uniform light source is installed on the lens. The seed delivery tube connects the seed outlet and the detection area; When the sensor at the seed outlet detects that there are seeds at the seed outlet, the conveyor turntable rotation assembly drives the conveyor turntable and the detection turntable to rotate synchronously. C. The rejection module includes: a guide chute, a telescopic robotic arm, and a rejection lever; There are two guide slots located on the outer edge of the detection turntable, and the inlet height of the guide slots is no higher than the top surface of the detection turntable; the positions of the two guide slots correspond to a set of two adjacent detection areas; there is a seed collection device below the outlet of the guide slots. The telescopic robotic arm is controlled to rotate between two guide grooves, and the rejection plate is installed at the front end of the telescopic robotic arm. When the telescopic robotic arm is retracted, the rejection plate leaves the surface of the detection turntable. When the telescopic robotic arm is extended, it rotates with the telescopic robotic arm, and the coverage area of ​​the rejection plate covers two adjacent detection areas, and the distance between the bottom surface of the rejection plate and the detection turntable is less than the thickness of a seed.

2. The seed external damage detection and rejection device based on machine vision according to claim 1, characterized in that: In the conveying module, the top surface of the conveying turntable is rough.

3. The seed external damage detection and rejection device based on machine vision according to claim 1, characterized in that: The support structure is an external support; the main body of the external support is a cubic frame, with transparent panels installed on the top and sides of the frame; The conveyor turntable, detection module, and rejection module are installed inside the cavity of the outer support; the funnel is installed on the top of the outer support, and the outlet of the funnel is on the top surface of the outer support. The side of the outer support is equipped with a door that can be opened and closed, and the position of the door corresponds to the position of the collection device.

4. The seed external damage detection and rejection device based on machine vision according to claim 1, characterized in that: In the conveying module, the outlet of the funnel is connected to an inner baffle for the initial dispersion of seeds; there are multiple parallel inner baffles, and adjacent inner baffles form a seed channel with the same width.

5. The seed external damage detection and rejection device based on machine vision according to claim 1, characterized in that: The seed metering channel has three levers at the end, which form the two side walls and the top surface of the end of the seed metering channel. The space enclosed by the three levers and the bottom surface of the seed metering channel allows only one seed to pass through. The main body of the sensor installed at the seed metering port is directly above the seed metering port, and the sensing end of the sensor faces the seed metering port.

6. The seed external damage detection and rejection device based on machine vision according to claim 1, characterized in that: The seed guide tube is divided into three sections: the seed inlet section and the seed outlet section are vertical pipes, and there is an inclined groove between the seed inlet section and the seed outlet section; the inlet of the seed inlet section is fixedly connected to the seed discharge port, and the projection of the seed outlet section is on the detection area of ​​the detection turntable.

7. The seed external damage detection and rejection device based on machine vision according to claim 1, characterized in that: The operational steps of the machine vision-based seed external damage detection and rejection device include: S1) Action 1: When the device is started, the conveyor turntable 102 rotates at a constant speed. The detection turntable rotates n degrees for one stroke. The motion mode is intermittent rotation. One stroke is completed every time t. S2) Action Two: Seeds enter through funnel 101, are initially dispersed by the inner baffle of the funnel, and then enter the conveyor turntable 102. The seeds are further dispersed as they pass through the dispersing baffles on the conveyor turntable; Guided by the guide baffle, the seeds flow to the edge of the conveyor turntable and enter the seed dispensing channel; S3) Action Three: After the sensor at the seed dispensing port of the seed dispensing channel detects the seeds, the conveyor turntable begins to dispense seeds intermittently at a frequency of t / seed, synchronized with the rotation of the detection turntable; Seeds fall into the detection area on the detection turntable through the seed guide tube. The detection turntable rotates clockwise by n° to move a single seed under the downward-facing lens for image acquisition of the seed's front side. After acquisition, the detection turntable rotates counterclockwise by n° to reach the upward-facing lens for image acquisition of the seed's back side. The images of the seed's front and back sides are sent to a computer equipped with detection and recognition algorithms for analysis, and a judgment is made on whether the seed is intact. S4) Action Four: After the judgment is completed, the detection turntable continues to rotate to move the seed to the rejection module position; If the judgment result is "qualified", the detection turntable rotates, the seeds reach the guide chute corresponding to the qualified seed collection device, the telescopic robotic arm extends and rotates, driving the rejection pick to send the qualified seeds into the guide chute and fall into the qualified seed collection device. If the judgment result is "unqualified", the detection turntable will continue to rotate until it reaches the guide chute corresponding to the unqualified seed collection device. The telescopic robotic arm drives the rejection pick to send the seed into the guide chute and fall into the unqualified seed collection device. S5) Action Five: When the seed metering sensor on the conveyor turntable does not detect seeds, the conveyor turntable continues to rotate at a constant speed until the sensor is triggered, at which point it begins to rotate intermittently in sync with the detection turntable.

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