Variable position cutting device for pull-type white radish harvester, control method and harvester

Abstract

The application relates to the technical field of agricultural mechanization, in particular to a variable-position cutting device for a pull-out white radish harvester, a control method and the harvester. The device comprises a walking chassis, a gathering device, a clamping and pulling device, a conveying device, a variable-position cutting device, a controller and a laser curtain detection device. The laser curtain detection device is installed on the clamping and pulling device and located in front of the variable-position cutting device, and is used for acquiring cross-sectional profile information of the white radish before the white radish reaches the variable-position cutting device. The laser curtain detection device comprises a laser curtain detection array formed by a plurality of laser ranging sensors in a vertical arrangement, and forms a detection curtain covering a white radish conveying channel. The plane of the detection curtain is perpendicular to the conveying direction of the white radish. The variable-position cutting device for the pull-out white radish harvester, the control method and the harvester can realize accurate cutting.

Description

Technical Field

[0001] This application relates to the field of agricultural mechanization technology, specifically to a repositioning and topping device, control method, and harvester for a pull-out type white radish harvester. Background Technology

[0002] With the development of agricultural mechanization, various types of mechanized harvesting methods for white radishes have emerged. Digging harvesters use digging devices to excavate the white radishes along with the soil from the ground. The soil is then removed through a series of separation devices before the tops are cut and the radishes are collected. This method is suitable for some small or shallow-growing white radish varieties, but it can easily damage larger, deeper-rooted radishes. Furthermore, the digging process introduces a large amount of soil, increasing subsequent processing costs.

[0003] Pull-up harvesters use a clamping device to pull the radish from the soil, then feed it through a conveyor chain to a topping device for topping removal and subsequent transport and collection. This solves some of the problems of digging harvesters, is well-adapted to common radish varieties, and can achieve high harvesting efficiency. Some pull-up harvesters also integrate intelligent control systems, enabling a degree of automation in the harvesting process. For example, sensors detect the position of the radish and automatically adjust the clamping and feeding position to ensure stable extraction.

[0004] Although mechanized harvesting technology for white radishes has made some progress, many problems still exist in the topping-cutting stage. White radishes have unique growth characteristics; their size varies at maturity, typically ranging from 25 to 40 cm in length and weighing 0.5 to 1 kg. Some radishes are exposed on the ridge surface at varying heights, and their thick stems and leaves present significant cutting resistance. Traditional topping-cutting methods mostly rely on fixed mechanical structures for cutting the toppings, making it difficult to adjust in real-time according to the actual shape of the radish and its dynamic position and posture during harvesting. In actual harvesting, due to the significant fluctuations in the position where the radish stems and leaves are held and pulled, when the holding position is close to the root of the radish, the traditional fixed-position topping-cutting method easily cuts into the radish, causing damage. According to relevant statistics, in current mechanized harvesting, the damage rate of white radishes due to topping-cutting can reach 10% to 20%, which not only reduces the commercial value of white radishes but also wastes resources. Moreover, traditional methods of cutting the radish tops cannot guarantee consistency. Sometimes the tops are left too long, affecting subsequent storage and transportation; other times the tops are cut too deep, which can also damage the radish fruit. Summary of the Invention

[0005] This invention aims to solve the problems in the prior art and provide a repositioning and topping-cutting device, control method, and harvester for a pull-out type white radish harvester that can accurately cut the toppings.

[0006] To achieve the above objectives, the first aspect of this application provides a repositioning and topping device for a pull-out type white radish harvester, comprising:

[0007] Walking chassis; The tassel-gathering device is installed at the front of the walking chassis and is used to gather the radish tassels to be harvested. A clamping and pulling device, including a frame, is installed behind the tassel-gathering device for clamping and pulling up the white radish; A conveying device, installed behind the clamping device, is used to convey white radishes; A flask-cutting device is installed below and behind the clamping device and on the conveying path of the conveying device, including a disc cutter for cutting radish flasks. The laser light curtain detection device is installed on the clamping and pulling device and located in front of the displacement and top-cutting device. It is used to obtain the cross-sectional contour information of the radish before it reaches the displacement and top-cutting device. The laser light curtain detection device includes a laser light curtain detection array composed of multiple laser rangefinders arranged vertically to form a detection light curtain covering the white radish conveying channel. The plane of the detection light curtain is perpendicular to the conveying direction of the white radish. The controller is configured to: locate the boundary point between the white radish fruit and the stem and leaves by identifying abrupt change points in the cross-sectional contour information of the white radish collected by the laser light curtain detection array, and control the displacement and tassel-cutting device to move to the target cutting height based on the position of the boundary point.

[0008] In one embodiment, the displacement and tassel-cutting device further includes: A composite transmission shaft system includes a ball spline shaft and a spline shaft sleeve sleeved on the bottom of the ball spline shaft and connected in transmission; the upper end of the ball spline shaft is connected to a drive motor, the spline shaft sleeve serves as the power output end, and a disc cutter is fixedly installed at its top end; the spline shaft sleeve is driven by a follow-up drive mechanism and slides along the axial direction of the ball spline shaft. The follow-up drive mechanism has its output end connected to the spline shaft sleeve.

[0009] In one embodiment, the follow-up drive mechanism includes a ball screw slide, a slide drive motor, and a spline shaft sleeve support; the slide drive motor drives the slider of the ball screw slide to perform linear motion; one end of the spline shaft sleeve support is fixed to the slider, and the other end is sleeved on the outside of the spline shaft sleeve to drive the axial sliding of the ball spline shaft.

[0010] In one embodiment, the laser light curtain detection array consists of at least two sets of laser ranging sensors, with at least one set arranged vertically at equal intervals on each side of the conveying channel to form a double-row symmetrical through-beam detection light curtain. Adjacent sensors are spaced 15-25 mm apart in the vertical direction, and each set of laser ranging sensors has at least six sensors.

[0011] In one embodiment, the laser light curtain detection device further includes a light curtain angle adjustment mechanism, which is electrically connected to the controller and is used to drive the laser light curtain detection array to rotate so that the plane of the detection light curtain is perpendicular to the natural downward direction of the white radish.

[0012] The second aspect of this application provides a control method based on the above-mentioned repositioning and topping device of a pull-out type white radish harvester, comprising the following steps: S10: Activate the laser light curtain detection device to obtain the cross-sectional contour information of the white radish when it passes through the detection light curtain; S20: Based on the cross-sectional contour information, identify the abrupt change points of the cross-sectional contour to locate the boundary between the white radish fruit and the stem and leaves; S30: Calculate the target cutting height based on the location of the dividing point and the preset tassel residual length; S40: Drive the follow-up drive mechanism to move the disc cutter from its current position to the target cutting height; S50: Control the disc cutter to cut the radish leaves at the target cutting height.

[0013] In one embodiment, in step S20, the difference in ranging values ​​between two adjacent vertical laser ranging sensors is calculated and compared with a preset threshold to identify abrupt changes in the cross-sectional profile; when the difference in ranging values ​​exceeds the preset threshold, the abrupt change is determined to be the boundary between the white radish fruit and the stem and leaves.

[0014] In one embodiment, determining the boundary point in S20 includes: Collect real-time ranging values ​​from all laser ranging sensors within the detection light curtain; Calculate the difference in ranging values ​​between two adjacent vertical laser rangefinders; When the difference in the measured distance exceeds a preset threshold, the area where the adjacent laser ranging sensor is located is determined as the boundary between the radish fruit and the stem and leaves.

[0015] In one embodiment, the calculation of the target cutting height in S30 further includes: shifting the position coordinates of the dividing point upwards by the preset tassel residual length to obtain the target cutting height.

[0016] The third aspect of this application is a pull-out radish harvester, including a pull-out radish harvester displacement and top-cutting device as described in any of the preceding claims.

[0017] Compared with existing technologies, this application has the following advantages: This application uses a laser light curtain detection array composed of multiple vertically arranged laser rangefinders to actively acquire the cross-sectional contour information of the radish before cutting. Based on the inherent diameter difference between the radish's fleshy root and the base of its stem and leaves, the boundary point between the radish fruit and its stem and leaves is located by analyzing the abrupt changes in the rangefinder values ​​caused by diameter changes in the cross-sectional contour information. This allows for precise identification of the boundary point. Furthermore, the controller drives the displacement-type top-cutting device to dynamically adjust the target cutting height of the disc cutter, achieving precise cutting of each radish and completely solving the problems of traditional fixed top-cutting methods that easily damage the fruit or leave excessively long tops. The use of a laser rangefinder sensor array for non-contact contour scanning, calculating the abrupt changes in the rangefinder values ​​between adjacent sensors to locate the boundary point, results in a simple and efficient algorithm. Moreover, by presetting the remaining top length, the length of the top can be flexibly controlled to meet the needs of different varieties or subsequent processing. This method is unaffected by environmental factors such as field lighting and dust, boasts high detection accuracy (millimeter-level), and fast response speed, meeting the real-time requirements of continuous harvester operation. Compared to image processing technology, it offers better environmental adaptability and lower cost.

[0018] Furthermore, the displacement tassel cutting device adopts a composite transmission shaft system composed of a ball spline rotating shaft and a spline shaft sleeve, combined with a follow-up drive mechanism driven by a ball screw slide table. While achieving high-speed cutting of the disc cutter, it ensures the smoothness and positional accuracy of its axial lifting motion, resulting in a compact structure and high reliability.

[0019] Furthermore, by setting up a light curtain angle adjustment mechanism, the direction of the laser beam of the detection light curtain can always be aligned with the natural downward direction of the radish. Even if the radish tilts during transportation, an accurate cross-sectional profile can be obtained, further improving the system's adaptability. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A schematic diagram of the overall structure of a pull-out radish harvester according to one embodiment; Figure 2 This is a schematic diagram of the assembly structure of the clamping and pulling device, the conveying device, and the displacement and tassel-cutting device according to one embodiment. Figure 3 A schematic diagram of the installation structure of a laser light curtain detection device according to one embodiment; Figure 4 A three-dimensional structural diagram of a displacement tassel-cutting device according to one embodiment; Figure 5 A cross-sectional view of a composite drive shaft system and a disc cutter mounting structure according to one embodiment; Figure 6 A schematic diagram of the follower drive mechanism structure according to one embodiment; Figure 7 A schematic diagram of a laser light curtain detection array and servo motor adjustment mechanism according to one embodiment; Figure 8 A schematic diagram illustrating the principle of cross-sectional contour recognition of a laser ranging sensor array according to one embodiment; Figure 9 This is a schematic diagram of the control method for the displacement and top-cutting device of a pull-out radish harvester, as one embodiment.

[0022] Reference numerals: 1: Tassel gathering device; 2: Clamping and pulling device; 3: Walking chassis; 4: Collecting device; 5: Laser light curtain detection device; 6: Displacement and tassel cutting device; 7: Conveying device; 21: Clamping frame; 22: Tensioner frame; 23: Tensioner; 24: Belt; 25: Belt pulley shaft; 26: Loosening shovel; 27: Bearing housing; 51: Laser light curtain detection array; 511: Laser rangefinder sensor; 52: Laser rangefinder light curtain fixing frame; 53: Laser light curtain detection array mounting plate; 54: Servo motor; 55: Servo motor output shaft locking connection plate; 61: Pulley; 62: Coupling; 63: Main drive motor; 64: Splined shaft sleeve; 65: Disc cutter; 66: Ball splined shaft; 71: Ball screw slide; 72: Ball screw; 73: Slide drive motor; 74: Screw coupling; 75: Splined shaft sleeve support. Detailed Implementation

[0023] To facilitate understanding of this application, the following description will be more comprehensive and detailed in conjunction with the accompanying drawings and preferred embodiments, but the scope of protection of this application is not limited to the following specific embodiments.

[0024] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of this application.

[0025] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0026] Please see Figures 1 to 8This invention provides a repositioning and topping-cutting device, a control method, and a radish harvester for a pulling-out type of white radish harvester. Specifically, as shown in the following... Figure 1 As shown, a top-cutting device for a pull-out radish harvester includes a chassis 3, a top-gathering device 1 mounted at the front of the chassis 3, a clamping and pulling device 2 mounted behind the top-gathering device 1, a conveying device 7 mounted behind the clamping and pulling device 2, a top-cutting device 6 mounted below and behind the clamping and pulling device 2 and located on the conveying path of the conveying device 7, and a laser light curtain detection device 5 mounted on the clamping and pulling device 2 and located in front of the top-cutting device 6. In one embodiment, the top-cutting device for a pull-out radish harvester is applied to a pull-out radish harvester. The harvester includes all the structures of the top-cutting device for a pull-out radish harvester, and also includes a collecting device 4 located behind the conveying device 7 for storing the radish fruits after top-cutting.

[0027] Specifically, the top-gathering device 1 has a V-shaped structure, used to gather the scattered radish tops in the field towards the center and guide them to the entrance of the clamping and pulling device 2. In one embodiment, the clamping and pulling device 2 includes a clamping and pulling frame 21, a tensioning wheel frame 22, a tensioning wheel 23, a belt 24, a pulley shaft 25, and a loosening shovel 26. Specifically, in one embodiment, the clamping and pulling frame 21 is welded from rectangular square tubing and is used to integrate structures such as a laser light curtain detection device 5, a displacement top-cutting device 6, and a conveying device 7. During harvesting, the clamping and pulling frame 21 is installed at an angle of 25-35°. The loosening shovel 26 is installed at the lower front of the clamping and pulling device 2 to slightly loosen the soil around the radish and reduce the pulling resistance. Two opposing belts 24 rotate in opposite directions under the drive of the tensioning wheel 23 and the pulley shaft 25, thereby clamping and pulling up the base of the radish tops. The pulled radish is then conveyed to the rear conveying device 7, which can be a conveyor chain or a conveyor belt.

[0028] like Figure 3 and Figure 8As shown, specifically, in one embodiment, the laser light curtain detection device 5 includes a laser light curtain detection array 51, a laser ranging light curtain fixing frame 52, and a laser light curtain detection array mounting plate 53. The laser ranging light curtain fixing frame 52 is locked to the square tube of the clamping and pulling frame with screws. Preferably, the laser light curtain detection array 51 is composed of multiple laser ranging sensors 511 arranged vertically at equal intervals. There are two sets of laser light curtain detection arrays 51, which are symmetrically arranged. In this embodiment, the laser light curtain detection array 51 consists of two sets of 16 laser ranging sensors. Eight laser ranging sensors are vertically arranged on each side of the conveying channel, and adjacent laser ranging sensors are spaced 15mm apart in the vertical direction. The total detection range covers a height of 120mm, forming a double-row symmetrical opposing beam detection light curtain covering the radish conveying channel. The plane of this detection light curtain is perpendicular to the conveying direction of the radish. In other embodiments, the number of laser ranging sensors can be 6 to 16, with a spacing of 15 to 25mm, as long as it can cover the radish fruit-stem-leaf transition area. As the radish passes laterally through the symmetrical through-beam detection light curtain via the conveyor device 7, each laser ranging sensor 511 independently measures its distance to the radish surface. The laser ranging sensor works by emitting a laser and receiving the reflected signal, measuring the distance from the sensor to the radish surface. Because the radish's fleshy root has a large diameter (small ranging value) and the stem and leaf base has a small diameter (large ranging value), by analyzing the contour curve formed by all sensor ranging values, the contour abrupt change point can be clearly identified, thus identifying the boundary between the radish fruit and the stem and leaves (i.e., the contour abrupt change point). This symmetrical through-beam detection light curtain can simultaneously acquire precise distance values ​​at multiple heights, equivalent to "scanning and imaging" the radish cross-section.

[0029] Preferably, in one embodiment, the laser light curtain detection device 5 further includes a light curtain angle adjustment mechanism. Preferably, in this embodiment, the light curtain angle adjustment mechanism is a servo motor 54. In other embodiments, the light curtain angle adjustment mechanism can also be composed of a rotary cylinder and a linkage mechanism: a single-acting or double-acting rotary cylinder as the actuator, and the cylinder output shaft is connected to the rotating shaft of the laser light curtain detection array via a linkage or directly. In this embodiment, the laser light curtain detection array mounting plate 53 is fixed to the output shaft of the servo motor 54 by locking the servo motor output shaft connection plate 55. More specifically, the servo motor 54 is fixedly installed at the joint connection of the laser ranging light curtain fixing frame 52, and its output shaft axis is perpendicular to the radish conveying direction; the laser light curtain detection array mounting plate 53 is fixed to the servo motor output shaft locking connection plate 55. When the servo motor rotates, it drives the entire laser light curtain detection array to rotate around the output shaft axis, thereby changing the pitch angle of the detection light curtain. The servo motor 54 is electrically connected to the controller. The servo motor 54 is preferably a metal servo motor. During actual harvesting, the white radish being pulled up may tilt at a certain angle due to different gripping points. The controller can drive the servo motor 54 to rotate, causing the entire laser light curtain detection array 51 to rotate, aligning the laser beam direction of the detection light curtain with the natural downward direction of the white radish. This ensures that the measurement accurately captures the true cross-sectional contour of the radish, thus obtaining precise distance values. Since the harvester frame is installed at a 25-35° angle during operation, the radish is naturally vertically downward due to gravity. The servo motor 54 drives the laser light curtain detection array 51 to rotate, automatically adjusting it to be aligned with the vertical axis of the radish, ensuring accurate cross-sectional scanning. The servo motor 54 has an angle adjustment range of 0-45°.

[0030] In one embodiment, the displacement trimming device 6 includes a main drive motor 63, a composite transmission shaft system, a disc cutter 65, and a follow-up drive mechanism. The composite transmission shaft system includes a ball spline shaft 66 and a spline shaft sleeve 64 sleeved at its bottom and connected by balls for transmission. The upper end of the ball spline shaft 66 is connected to the output shaft of the main drive motor 63 via a coupling 62, or it can obtain power via a pulley 61. The spline shaft sleeve 64 serves as the power output end, and the disc cutter 65 is fixedly mounted at its top. The ball spline shaft 66 has spline teeth on its surface and an integrated ball structure inside, serving both rotational power transmission and axial sliding guidance functions. The spline shaft sleeve 64 is sleeved at the bottom of the ball spline shaft 66, and through the meshing of the balls and spline teeth, it can rotate synchronously and slide freely along the axial direction. The splined shaft sleeve 64 is driven by a follower drive mechanism and can slide freely along the axial direction (i.e., vertical direction) of the ball splined shaft 66, realizing the vertical displacement of the disc cutter 65. The disc cutter 65 consists of two disc cutters arranged side by side and fixed to the top stepped surface of the splined shaft sleeve 64 by bolts. A gap of 5-10mm is left between the two disc cutters, and the cutting edges rotate relative to each other to create a shearing effect. The rotational torque of the ball splined shaft 66 can be smoothly transmitted to the splined shaft sleeve 64, driving the disc cutter 65 to cut at high speed.

[0031] The follow-up drive mechanism includes a ball screw slide 71, a slide drive motor 73, and a splined shaft sleeve support 75. The slide drive motor 73 drives the ball screw 72 to rotate via a screw coupling 74, thereby causing the slider of the ball screw slide 71 to perform precise linear motion. Preferably, the slide drive motor 73 is a stepper motor, and the output shaft of the slide drive motor 73 is connected to the ball screw via the screw coupling 74 to compensate for installation eccentricity and buffer impact. The screw coupling 74 is preferably a flexible coupling. One end of the splined shaft sleeve support 75 is fixed to the slider of the ball screw slide 71, and the other end is sleeved on the outside of the splined shaft sleeve 64 through a rolling bearing. The inner ring of the rolling bearing is fixed to the splined shaft sleeve 64, and the outer ring is fixed to the splined shaft sleeve support 75, so that the splined shaft sleeve 64 can rotate freely within the splined shaft sleeve support 75. At the same time, the splined shaft sleeve support 75 can drive the splined shaft sleeve 64 to move axially, realizing dynamic adjustment of the cutting height. The disc cutter 65 can realize vertical follow-up adjustment of 0-100mm stroke, with a positioning accuracy of ≤0.05mm.

[0032] The controller (not shown in the figure, usually a PLC or embedded microcontroller) is electrically connected to the laser light curtain detection device 5, the main drive motor 63, the slide drive motor 73, and the servo motor 54. The controller has a preset tassel residual length (generally 15-25mm, preferably 20mm, but can also be set according to user requirements).

[0033] Based on the above device, please refer to Figure 9 The specific steps of the control method for the repositioning and topping device of the pull-out type white radish harvester in this application are as follows: S10: Activate the laser light curtain detection device to obtain the cross-sectional contour information of the white radish when it passes through the detection light curtain; Specifically, when the laser light curtain detection device 5 is activated, and the white radish is driven by the conveying device 7, and the white radish fruit and stem and leaf parts begin to pass through the laser light curtain detection array 51, the controller collects the real-time ranging values ​​of all laser ranging sensors 511 to obtain the contour information of the white radish on that cross section.

[0034] S20: Based on the cross-sectional contour information, identify the abrupt change points of the cross-sectional contour to locate the boundary between the white radish fruit and the stem and leaves; Specifically, the controller calculates the difference in ranging values ​​between two adjacent laser rangefinders 511 in the vertical direction. For example... Figure 8As shown, from top to bottom, when the difference in the distance measurement value suddenly changes from close to zero (small change in the outline of the stem and leaf segment) to a positive change exceeding a preset threshold (e.g., 25 mm, which can be calibrated according to the radish variety, generally 20-30 mm), the middle position of the area where the adjacent laser distance sensor 511 is located is determined to be the dividing point between the white radish fruit and the stem and leaf.

[0035] S30: Calculate the target cutting height based on the location of the dividing point and the preset tassel residual length; Specifically, the controller extracts the position coordinates of the dividing point (i.e., its height value in the vertical direction), and then, based on these coordinate values, offsets the preset tassel residual length upwards (i.e. towards the stem and leaf direction) to calculate the final target cutting height.

[0036] S40: Drive the follow-up drive mechanism to move the disc cutter from its current position to the target cutting height; Specifically, the controller sends pulse commands to the slide drive motor 73, which drives the slider of the ball screw slide 71 to move, and drives the disc cutter 65 to move quickly and accurately from the current height up or down to the target cutting height through the splined shaft sleeve support 75.

[0037] S50: The disc cutter cuts the radish leaves at the target cutting height.

[0038] Specifically, the disc cutter 65 rotates at high speed under the drive of the main drive motor 63. When the stem and leaves of the radish reach the target cutting height during conveying, the disc cutter 65 cuts them off, completing the top-cutting operation. The top-cut radish fruit continues to be conveyed to the collection device 4.

[0039] For each radish that passes through continuously, the controller repeats steps S10 to S50 above to achieve adaptive displacement cutting one by one.

[0040] The present application discloses a radish harvester with a repositioning and topping-cutting device and a radish harvester. Through a composite transmission shaft system consisting of a ball-spindle spindle and a spline shaft sleeve, the cutting and axial sliding of the disc cutter are integrated into one unit. Vertical follow-up with a stroke of 0-100mm can be achieved without additional slide rails. With the precise drive of the ball screw slide and stepper motor, the positioning accuracy is ≤0.05mm and the response speed is ≥80mm / s. The structure is compact and the transmission gap is small, which fundamentally overcomes the mechanical defects of traditional fixed cutters that cannot adapt to individual differences in radishes. At the same time, a double-row through-beam detection light curtain formed by multiple sets of vertically arranged laser rangefinder sensors, together with a servo motor-driven automatic light curtain angle adjustment mechanism, can always be aligned with the natural downward direction of the radish when the harvester is tilted. It can stably obtain information on the cross-sectional contour of the radish. Moreover, the laser rangefinder principle has strong resistance to strong light and dust interference, providing a reliable and all-weather sensing basis for precise topping cutting, thereby effectively reducing the fruit damage rate and improving the consistency of topping cutting. Based on this, the control method of this application directly locates the abrupt change point between the radish fruit and the stem and leaf section as the dividing benchmark by calculating the difference in the ranging values ​​of adjacent vertical laser ranging sensors and comparing it with a preset threshold. This algorithm only requires subtraction and comparison operations, with low computational load and fast response. In principle, it avoids the misjudgment problem caused by the deformation of the tassel posture in the traditional "tassel length measurement" method. Then, the target cutting height is calculated based on the height of the dividing point and the preset tassel residual length. The current position of the cutter is read and the cutter is driven to move precisely to the target height, realizing adaptive follow-up cutting for each white radish. The bench test verified that the qualified cutting rate (tassel residual length 15-25mm) using the device and control method of this invention is not less than 96%, which is about 6-16 percentage points higher than the traditional fixed tassel cutting device. It effectively reduces the cutting damage rate and the missed cutting rate, and significantly improves the marketability of the harvested white radish.

[0041] Example The following example illustrates this using a complete work cycle: The harvester enters the field, and the chassis 3 drives the entire machine forward. The top-gathering device 1 gathers the radish tops and leaves. The pull-type radish harvester is powered on, and the servo motor 54 automatically adjusts the angle of the laser light curtain detection array 51 to make it perpendicular to the vertical downward direction of the radish. The operator sets the residual length of the tops and leaves to 20mm on the screen. The main drive motor 63 starts, the belt 24 of the clamping and pulling device 2 rotates, and the loosening shovel 26 loosens the soil. The clamping and pulling device 2 clamps the base of the radish tops and leaves, pulls the radish out of the soil, and transports it laterally. The radish first passes through the laser light curtain detection area: 16 industrial-grade laser rangefinders simultaneously measure the distance, and the data is collected by the embedded controller. The controller runs the cross-sectional abrupt change point identification algorithm: calculating Δd _i Δd was detected _4If the difference is ≥25mm (a sudden change occurs between the fourth (S4) and fifth (S5) laser rangefinder sensors counting from the top), then H(S4) = 80mm is determined as the dividing point. Calculate the target cutting height: H _target = 80mm + 20mm = 100mm. The current height of the disc cutter 65 is read as 50mm. ΔH = 50mm, N_pulse = 50mm / 0.0125mm / pulse = 4000 pulses. The controller sends a drive signal, and the stepper motor drives the lead screw slide, raising the disc cutter 65 by 50mm to the target height of 100mm. The radish stem and leaves are cut off at the disc cutter 65, leaving a 20mm long tassel. The cut radish fruit falls into the collection device 4. The next radish enters the light curtain detection area, and the above operation is repeated.

[0042] The above are merely preferred embodiments of this application. It should be noted that this application is not limited to the above embodiments. For those skilled in the art, several improvements and modifications can be made without departing from the principles of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should also be considered within the scope of protection of this application.

Claims

1. A repositioning and topping device for a pull-out type white radish harvester, characterized in that, include: Walking chassis; The tassel-gathering device is installed at the front of the walking chassis and is used to gather the radish tassels to be harvested. A clamping and pulling device, including a frame, is installed behind the tassel-gathering device for clamping and pulling up the white radish; A conveying device, installed behind the clamping device, is used to convey white radishes; A flask-cutting device is installed below and behind the clamping device and on the conveying path of the conveying device, including a disc cutter for cutting radish flasks. The laser light curtain detection device is installed on the clamping and pulling device and located in front of the displacement and top-cutting device. It is used to obtain the cross-sectional contour information of the radish before it reaches the displacement and top-cutting device. The laser light curtain detection device includes a laser light curtain detection array composed of multiple laser rangefinders arranged vertically to form a detection light curtain covering the white radish conveying channel. The plane of the detection light curtain is perpendicular to the conveying direction of the white radish. The controller is configured to: locate the boundary point between the white radish fruit and the stem and leaves by identifying abrupt change points in the cross-sectional contour information of the white radish collected by the laser light curtain detection array, and control the displacement and tassel-cutting device to move to the target cutting height based on the position of the boundary point.

2. The repositioning and topping device for a pull-out type white radish harvester according to claim 1, characterized in that: The displacement shearing device also includes: A composite transmission shaft system includes a ball spline shaft and a spline shaft sleeve sleeved on the bottom of the ball spline shaft and connected in transmission; the upper end of the ball spline shaft is connected to a drive motor, the spline shaft sleeve serves as the power output end, and a disc cutter is fixedly installed at its top end; the spline shaft sleeve is driven by a follow-up drive mechanism and slides along the axial direction of the ball spline shaft. The follow-up drive mechanism has its output end connected to the spline shaft sleeve.

3. The repositioning and topping device for a pull-out type white radish harvester according to claim 2, characterized in that: The follow-up drive mechanism includes a ball screw slide, a slide drive motor, and a spline shaft sleeve support. The slide drive motor drives the slider of the ball screw slide to move linearly. One end of the spline shaft sleeve support is fixed to the slider, and the other end is sleeved on the outside of the spline shaft sleeve to drive the axial sliding of the ball spline shaft.

4. The repositioning and topping device for a pull-out type white radish harvester according to claim 1, characterized in that: The laser light curtain detection array consists of at least two sets of laser ranging sensors, with at least one set arranged vertically at equal intervals on each side of the conveying channel to form a double-row symmetrical through-beam detection light curtain. Adjacent sensors are spaced 15-25 mm apart in the vertical direction, and each set of laser ranging sensors has at least six sensors.

5. The repositioning and topping device for a pull-out type white radish harvester according to claim 1, characterized in that: The laser light curtain detection device also includes a light curtain angle adjustment mechanism, which is electrically connected to the controller and is used to drive the laser light curtain detection array to rotate so that the plane of the detection light curtain is perpendicular to the natural downward direction of the white radish.

6. A control method for a radish harvester with a repositioning and topping device according to any one of claims 1 to 5, characterized in that, Includes the following steps: S10: Activate the laser light curtain detection device to obtain the cross-sectional contour information of the white radish when it passes through the detection light curtain; S20: Based on the cross-sectional contour information, identify the abrupt change points of the cross-sectional contour to locate the boundary between the white radish fruit and the stem and leaves; S30: Calculate the target cutting height based on the location of the dividing point and the preset tassel residual length; S40: Drive the follow-up drive mechanism to move the disc cutter from its current position to the target cutting height; S50: Control the disc cutter to cut the radish leaves at the target cutting height.

7. The control method according to claim 6, characterized in that: In step S20, the difference in ranging values ​​between two adjacent vertical laser ranging sensors is calculated and compared with a preset threshold to identify abrupt changes in the cross-sectional profile. When the difference in ranging values ​​exceeds the preset threshold, the abrupt change is determined to be the boundary between the white radish fruit and the stem and leaves.

8. The repositioning and topping device for a pull-out type white radish harvester according to claim 1, characterized in that: The determination of the boundary point mentioned in S20 includes: Collect real-time ranging values ​​from all laser ranging sensors within the detection light curtain; Calculate the difference in ranging values ​​between two adjacent vertical laser rangefinders; When the difference in the measured distance exceeds a preset threshold, the area where the adjacent laser ranging sensor is located is determined as the boundary between the radish fruit and the stem and leaves.

9. The repositioning and topping device for a pull-out type white radish harvester according to claim 8, characterized in that: The calculation of the target cutting height of S30 also includes: shifting the position coordinates of the dividing point upwards by the preset tassel residual length to obtain the target cutting height.

10. A pull-type white radish harvester, characterized in that: The device includes the detachable top-cutting device for a pull-out radish harvester as described in any one of claims 1 to 5.

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