Potato picking device, potato stress calculation method and self-adaptive control method

Abstract

The invention relates to the field of potato collecting equipment, in particular to a potato picking device, a potato stress calculation method and a self-adaptive control method.The picking device comprises a shell, a shovel piece is arranged at the bottom of the front portion of the shell, a potato shifting mechanism and a potato guiding mechanism are sequentially arranged in the shell from front to back, and a collecting box is arranged behind the potato guiding mechanism; the collecting box is fixedly connected to the shell and communicates with the inner space of the shell. According to the automatic potato picking device, actions such as potato collection can be automatically completed, and the potatoes are prevented from being damaged in the collection process; the picking claws which rotate circularly and stretch out and retract periodically are adopted, the picking distance can be prolonged, falling and other situations in the collecting process are avoided, the picking claws can be prevented from being staggered with the potato guiding plates on the rear portion, and the situation that potatoes are damaged or the device is damaged by stones is avoided.

Description

Technical Field

[0001] The invention relates to the field of potato collecting equipment, in particular to a potato picking device, a potato force calculation method and an adaptive control method. Background Art

[0002] The potato industry is developing rapidly, but the low degree of mechanization is the main problem restricting its development. The domestic harvesting method has problems with breakage and high impurity rates, which is not conducive to storage. At present, my country's potato harvesting mainly relies on mechanical digging and manual picking. This method has a low degree of mechanization, high labor intensity, time-consuming and high cost, which restricts the development of the industry.

[0003] "Key Design of Potato Picker" discloses a potato picker. During operation, the anti-leakage potato fence gathers the edge potatoes to the center, and the picking shovel sends the soil-containing potatoes into the separation conveyor chain. The soil falls back to the ground, and the potatoes are transported to the rake teeth. The rake teeth lift the potatoes to a high place, throw them out and hit the rubber curtain before falling into the potato collection box. Although the machine has improved the picking efficiency, the potato leakage rate and potato damage rate are still high. "Experimental Study on Potato Picking Device Based on Discrete Element" discloses a disc potato picking device. The potatoes spread on the surface by the potato digger digging bars are picked up by the picking disc. When it rotates to 3 / 4 of the highest point of the picking disc, the potatoes fall on the potato guide plate due to gravity, and the potatoes slide onto the conveyor belt and move to the tail of the device. They are collected by manual bagging through the potato collecting device. The mechanical structure is simple in design and has high reliability, but the potato falling height is too high, resulting in a significant increase in the potato damage rate. "Research on the Experimental Study of the Spring-Tine Potato Picker and its Picking Performance" discloses a spring-tine potato picking device, whose main drive shaft drives the drum disc and the spring-tine shaft to rotate. The roller is connected to the crank and the spring-tine shaft, and rolls in the cam slide to control the movement trajectory of the spring-tine. The cam is fixed on the frame. When the picking spring teeth move to the lowest point, they extend to the outside of the arc-shaped cover, insert into the ground to pick up potatoes. After the potatoes rise to the highest point with the spring teeth, they roll into the potato collection box, and the spring teeth retract to complete the picking operation. During the operation of this machine, there is a problem of soil accumulation caused by the machine entering the soil too much, and some potatoes are missed.

[0004] In summary, the potato picking devices studied by different experts and scholars have their own advantages and disadvantages, but none of them can completely solve the problems of potato leakage, potato damage and soil accumulation. Summary of the invention

[0005] The present invention aims to solve the above problems and provides a potato picking device and a potato force calculation method, the technical solutions adopted by the present invention are as follows: A potato picking device comprises a shell, a shovel blade is arranged at the front bottom of the shell, a potato-pulling mechanism and a potato-guiding mechanism are arranged in sequence from front to back in the shell, a collecting box is arranged behind the potato-guiding mechanism, the collecting box is fixedly connected to the shell and communicated with the inner space of the shell; the potato-pulling mechanism is arranged above the shovel blade, and transfers the potatoes on the shovel blade to the potato-guiding mechanism; the potato-guiding mechanism comprises a potato-guiding wheel, a potato-guiding ring, a picking claw and a potato-guiding plate, the potato-guiding wheel is fixedly arranged on the shell, a sliding groove is arranged on the potato-guiding wheel, a plurality of potato-guiding rings are arranged, the potato-guiding rings rotate synchronously and are arranged coaxially with the potato-guiding wheel, and the picking claws and the potato-guiding rings are staggered It is arranged that the potato guide ring is fixedly connected to the rotating frame, the end of the picking claw is hinged on the rotating frame, the middle part of the picking claw is hinged to the roller, the roller is clamped in the slide groove and moves along the slide groove, the potato guide plate is arranged between the potato guide ring and the collection box, and the height of the potato guide plate is gradually reduced; the picking claw gradually extends outward after passing the potato guide plate at the rear side and rotates to the bottom, and is fully extended when it reaches the bottom of the potato guide ring. When the picking claw rotates upward from the front side to the upper side of the potato guide ring, it begins to retract into the potato guide ring until it reaches the potato guide plate and retracts to the limit position. At this time, the rear end edge line of the picking claw does not exceed the front end edge line of the potato guide plate.

[0006] On the basis of the above scheme, the potato guide plate is composed of a strip structure, the number of the strip structures is multiple and they are arranged in parallel in the horizontal direction, and the picking claws are correspondingly arranged at the interval positions between adjacent strip structures.

[0007] Preferably, the potato guide mechanism also includes a potato guide shaft, the rotating frame is fixedly connected to the potato guide shaft and rotates synchronously, a connecting frame is fixedly arranged between the end of the rotating frame and the potato guide ring, a hinged rod is fixedly arranged between the ends of adjacent connecting frames, the hinged rod is coaxially arranged, the end of the picking claw is hinged on the hinged rod, a connecting rod is arranged through the middle of the picking claw close to the hinged rod, and the roller is rotatably arranged at the end of the connecting rod.

[0008] Preferably, the potato stirring mechanism includes a potato stirring wheel, a potato stirring roller and a potato stirring shaft. The potato stirring wheel is fixedly connected to both ends of the potato stirring shaft and rotates synchronously with the potato stirring shaft. The potato stirring roller is fixedly connected between the potato stirring wheels and is parallel to the potato stirring shaft. There are multiple potato stirring rollers, which are evenly distributed circumferentially at the edge of the potato stirring wheel.

[0009] Preferably, the potato pulling mechanism further includes a potato pulling drive mechanism, and the potato guiding mechanism further includes a potato guiding drive mechanism, and the potato pulling drive mechanism moves synchronously with the potato guiding drive mechanism.

[0010] Preferably, a seedling removing mechanism is arranged between the potato guiding mechanism and the collecting box, and the seedling removing mechanism comprises a seedling removing roller and a seedling blocking plate. The seedling removing roller is arranged at the end of the potato guiding plate and is parallel to the axis of the potato guiding ring. The seedling removing rollers are arranged in pairs along the longitudinal direction and roll relative to each other. Grooves are arranged on the surfaces of the seedling removing rollers. The seedling blocking plate is arranged behind the seedling removing rollers. The lower edge of the seedling blocking plate is lower than the upper edge of the lower seedling removing roller, and the seedling blocking plate is made of flexible material.

[0011] Preferably, shovel teeth are fixedly arranged on the upper side of the shovel blade, and there are multiple shovel teeth. The shovel teeth are arranged protruding from the surface of the shovel blade, and the front end of the shovel teeth is conical and protruding from the front end of the shovel blade; the rear of the shovel blade is fixedly connected to the grid bars, which extend from front to back to the bottom of the potato guide mechanism. There are multiple grid bars, and gaps are set between adjacent grid bars.

[0012] A method for calculating the force on potatoes, wherein the potatoes move in the above-mentioned potato picking device, and the calculation method comprises the following steps: A1. When the potato is driven to the top of the potato guide ring by the picking claw, the hinge point at the end of the picking claw is defined as point A, the hinge point in the middle of the picking claw is defined as point B, the rotation center of the potato is point O, the rotation center of the potato guide ring is point O, and the potato guide ring rotates at an angular velocity of Rotate at a constant speed; A2. Kinematic analysis of the potato and the potato guide mechanism yields (1) In the formula is the velocity of point B, m / s; is the velocity of point A, m / s; is the speed of point B relative to point A, m / s; is the velocity of point C relative to point A, m / s; is the velocity of point C relative to point B, m / s; A3. According to the vector diagram method, we can get (2) (3) (4) (5) (6) (7) (8) Where: l AO is the distance from point A to point O, m; is the angular velocity of the AO segment; α is the angle between the velocity direction of point A and the velocity direction of point B, °; β is the angle between the velocity direction of point A and the velocity direction of point B relative to point A, °; γ is the angle between the velocity direction of point B relative to point A and the velocity direction of point C relative to point A, °; ζ is the angle between the velocity direction of point C and the horizontal line, °; V Cx is the horizontal velocity of point C, m / s; V Cy is the vertical velocity of point C, m / s; A4. Perform kinematic analysis on the falling process of the potato, define point D as the initial contact point between the potato and the potato guide ring, point E as the final contact point between the potato and the potato guide ring, and segment DE as an arc with a radius of R. DE Point F is the first contact point between the potato and the potato guide plate, point G is the first connection point on the potato guide plate, and the FG segment is an arc with a radius of R. FG , point H is the second connection point of the potato guide plate, segment GH is a straight line, point I is the third connection point of the potato guide plate, and point I is the lowest point of the potato guide plate, segment HI is an arc with a radius of R HI , point J is the final contact point between the potato and the potato guide plate, and segment IJ is a straight line; a rectangular coordinate system is established with point O as the center and OC as the Y axis, then the motion trajectory equation of the potato is (9) The equations of each line segment are: The expression of arc DE segment: (10) The expression of the horizontal line EF segment is: (11) The expression of arc FG segment: (12) The expression of the oblique straight line GH segment is: (13) The expression of arc HI segment is: (14) The expression of the oblique straight line IJ segment is: (15) The piecewise function of the potato's moving trajectory on each curve segment is obtained as follows: (16) Where t is the time of potato movement, s; l D , l E , l F , l G , l H , l I , lJ are the horizontal coordinates of each point, m; h C 、h D 、h E 、h F 、h G 、h H 、h I 、h J are the ordinates of each point, m; l DE , l FG , l HI are the horizontal coordinates of the centers of arcs DE, FG, and HI, m; h DE 、h FG 、h HI are the ordinates of the centers of arcs DE, FG, and HI, respectively, in m; A5. Analyze the force of potatoes during the falling process. When potatoes fall onto the potato guide ring or potato guide plate, they are subjected to the normal reaction force and friction force of the potato guide ring or potato guide plate. The normal reaction force is (17) Where v0 is the speed of the potato when it just contacts the potato guide ring or potato guide plate, m / s; θ is the angle between the speed of the potato when it just contacts the potato guide ring or potato guide plate and the tangent line at the contact point, °; F N is the normal reaction force of the contact surface between potato and potato guide ring or potato guide plate, N; From the beginning of the collision to the maximum compression state of the potato, the normal reaction force F N From zero to the maximum value F Nm ,but (18) (19) (20) (twenty one) (twenty two) (twenty three) (twenty four) (25) (26) (27) Where λ is the angle between the tangent line of the potato just touching the potato guide ring or potato guide plate and the horizontal line, °; φ is the angle between the speed of the potato just touching the potato guide ring or potato guide plate and the horizontal line, °; F fis the friction force when the potato contacts the potato guide ring or potato guide plate, N; Δt is the time from the beginning of the collision to the maximum compression state, s; R s is the average radius of the potato, m; m is the mass of the potato, kg; F m v is the maximum force on the potato when it contacts the potato guide ring or potato guide plate, N; x v is the horizontal speed of the potato when it first touches the potato guide ring or potato guide plate, m / s; y is the vertical speed of the potato when it just contacts the potato guide ring or potato guide plate, m / s; μ is the friction coefficient of the potato guide ring or potato guide plate.

[0013] A potato picking device adaptive control method, using the above-mentioned potato picking device, comprises the following steps: B1. Periodically collect the potato guide ring speed V0 and the potato guide mechanism torque T0 of the picking device; B2. Determine whether the torque T0 is within a preset range; if not, proceed to step C1; if within the preset range, proceed to step D1; C1. Input the collected potato ring speed V0 and potato mechanism torque T0 into the first BP neural network to calculate the potato ring speed V1 at the next moment; C2. The speed V1 of the guide potato ring is input into the PID controller, and the PID controller outputs the adjusted speed V1 of the guide potato ring. The system input, system output and system error of the PID controller are input into the second BP neural network, and the integral adjustment coefficient, proportional adjustment coefficient and differential adjustment coefficient of the adjusted PID controller are calculated and output by the second BP neural network; C3. Collect the torque T1 at the next moment and proceed to step B2; D1. Record the collected potato guide ring speed V0 and potato guide mechanism torque T0 as a set of data; D2. When the data sample records are full of 10 groups, the data set is updated by cyclic overwriting; D3. The updated data set is input into the first BP neural network for training, and the weight of the first BP neural network is updated.

[0014] Based on the above scheme, the initial data set of the adaptive system contains 200 groups of data samples, and the data set is randomly divided into training set and validation set in the ratio of 8:2; in the initial stage of adaptation, the allowable variation range of the preset torque of the guide mechanism is increased to a times the rated allowable variation range, and each time the data set is updated, the allowable variation range of the torque of the guide mechanism is reduced proportionally, until after the data set is updated 20 times, the allowable variation range of the torque of the guide mechanism is reduced to the rated allowable variation range, and the initial data set is completely covered.

[0015] The beneficial effects of the present invention are: 1. An automatic potato picking device is proposed, which can automatically complete potato harvesting, preliminary soil screening, vine removal, collection and other actions, reduce the throwing height and throwing distance during potato collection, and avoid damage to potatoes during the collection process; 2. The picking claws rotate cyclically and extend and retract periodically, which can not only extend the picking distance and avoid dropping during the collection process, but also prevent the picking claws from crossing with the potato guide plate at the rear, thus avoiding damage to potatoes or stones. 3. By analyzing and calculating the force and kinematics of potato throwing, the integrity and lossless rates of potato collection can be effectively improved; 4. An adaptive control method for the picking device is proposed, which can autonomously learn the indicators in the working environment, so that the various mechanisms of the picking device match the forward speed of the picking device and improve the picking efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 : Schematic diagram of the structure of the present invention; Figure 2 : Schematic diagram of the internal structure of the housing of the present invention; Figure 3 : Front view of the internal structure of the shell of the present invention; Figure 4 : An enlarged view of the local structure of the potato-guiding mechanism of the present invention; Figure 5 : Schematic diagram of kinematic analysis of the potato guiding mechanism of the present invention; Figure 6 : The present invention Figure 5 Simplified model diagram of kinematic analysis; Figure 7 : The potato velocity vector decomposition diagram of the present invention; Figure 8 : Schematic diagram of the potato movement direction of the present invention; Fig. 9 : Schematic diagram of the potato movement path of the present invention; Fig.10 : A schematic diagram of the force on potatoes during horizontal throwing of the present invention; Fig.11 : Flow chart of the adaptive control method of the present invention; Fig.12 : Schematic diagram of the adaptive control system of the present invention; Fig.13 : The first neural network structure diagram of the present invention; Fig.14 : The second neural network structure diagram of the present invention. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] In the description of the present invention, it should be understood that the terms "center", "length", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0019] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0020] like Figures 1 to 4 As shown, a potato picking device comprises a shell 11, on which a depth-limiting wheel 13 and a connecting frame are arranged. When in use, a tractor or other driving device at the front is fixedly connected to the connecting frame to drive the picking device to move.

[0021] A shovel 21 is provided at the front bottom of the shell 11, and a potato-pulling mechanism and a potato-guiding mechanism are provided in the shell 11 from front to back. A collecting box 12 is provided behind the potato-guiding mechanism. The collecting box 12 is fixedly connected to the shell 11 and communicated with the internal space of the shell 11 for collecting potatoes in the shell 11.

[0022] The shovel blade 21 is fixedly provided with shovel teeth 22 on the upper side. There are multiple shovel teeth 22. The shovel teeth 22 are arranged to protrude from the surface of the shovel blade 21. The front end of the shovel teeth 22 is conical and protrudes from the front end of the shovel blade 21, so as to facilitate scooping up potatoes in the soil and guiding them onto the shovel blade 21. The rear of the shovel blade 21 is fixedly connected with a grid bar 23, which extends from front to back to the bottom of the potato guiding mechanism. There are multiple grid bars 23, and intervals are arranged between adjacent grid bars 23, so as to facilitate catching the fallen potatoes when the potatoes move at the potato digging mechanism and the potato guiding mechanism, and at the same time make the soil attached to the potatoes fall off and fall into the ground through the grid bars 23.

[0023] The potato-pushing mechanism is arranged above the shovel blade 21, and transfers the potatoes on the shovel blade 21 to the potato-guiding mechanism; the potato-pushing mechanism includes a potato-pushing wheel 31, a potato-pushing roller 32 and a potato-pushing shaft 33, wherein the potato-pushing wheel 31 is fixedly connected to both ends of the potato-pushing shaft 33 and rotates synchronously with the potato-pushing shaft 33, the potato-pushing roller 32 is fixedly connected between the potato-pushing wheels 31 and is parallel to the potato-pushing shaft 33, and the number of the potato-pushing rollers 32 is multiple and is evenly distributed along the circumferential direction at the edge of the potato-pushing wheel 31. When the potato-pushing wheel 31 rotates, the potato-pushing roller 32 picks up the potatoes on the shovel blade 21, and transfers the potatoes to the potato-guiding mechanism as the potato-pushing wheel 31 rotates.

[0024] The potato guiding mechanism includes a potato guiding wheel 411, a potato guiding ring 424, a picking claw 431 and a potato guiding plate 44. The potato guiding wheel 411 is fixedly arranged on the shell 11, and a slide groove 412 is arranged on the potato guiding wheel 411. There are multiple potato guiding rings 424, which rotate synchronously and are coaxially arranged with the potato guiding wheel 411. The picking claw 431 and the potato guiding ring 424 are staggered. The potato guiding ring 424 is fixedly connected to the rotating frame 422. The end of the picking claw 431 is hinged on the rotating frame 422. The middle part of the picking claw 431 is hinged to the roller 432. The roller 432 is clamped in the slide groove 412 and moves along the slide groove 412. Specifically, the potato guide mechanism also includes a potato guide shaft 421, the rotating frame 422 is fixedly connected to the potato guide shaft 421 and rotates synchronously, a connecting frame 423 is fixedly arranged between the end of the rotating frame 422 and the potato guide ring 424, a hinged rod is fixedly arranged between the ends of adjacent connecting frames 423, the hinged rod is coaxially arranged, the end of the picking claw 431 is hinged on the hinged rod, and a connecting rod 433 is arranged through the middle of the picking claw 431 close to one side of the hinged rod, and the roller 432 is rotatably arranged at the end of the connecting rod 433.

[0025] The potato guide plate 44 is arranged between the potato guide ring 424 and the collection box 12, and the height of the potato guide plate 44 gradually decreases; the potato guide plate 44 is composed of a strip structure, the number of the strip structures is multiple, and they are arranged in parallel in the horizontal direction, and the picking claws 431 are correspondingly arranged at the interval positions between adjacent strip structures.

[0026] The picking claw 431 gradually extends outward and rotates to the bottom after passing the potato guide plate 44 at the rear side. When the picking claw 431 reaches the bottom of the potato guide ring 424, it is fully extended, so that when moving forward from the bottom, the potatoes dropped between the potato rollers 32 can be picked up and the movement can continue. When the picking claw 431 rotates upward from the front side to the upper side of the potato guide ring 424, it begins to retract into the potato guide ring 424 until it reaches the potato guide plate 44 and retracts to the limit position. At this time, the rear end edge line of the picking claw 431 does not exceed the front end edge line of the potato guide plate 44, thereby preventing the picking claw 431 from cutting the potatoes when it is staggered with the potato guide plate 44, and also preventing stones and other debris that fall on the potato guide plate 44 from cutting.

[0027] The potato-pulling mechanism further includes a potato-pulling driving mechanism 34, and the potato-guiding mechanism further includes a potato-guiding driving mechanism 45. The potato-pulling driving mechanism 34 moves synchronously with the potato-guiding driving mechanism 45. The potato-pulling driving mechanism 34 and the potato-guiding driving mechanism 45 can be mutually meshing gear transmission mechanisms.

[0028] A seedling removal mechanism is arranged between the potato guide mechanism and the collection box 12, and the seedling removal mechanism includes a seedling removal roller 51 and a seedling prevention plate 52. The seedling removal roller 51 is arranged at the end of the potato guide plate 44 and is parallel to the axis of the potato guide ring 424. The seedling removal rollers 51 are arranged in pairs along the longitudinal direction and roll relative to each other. Grooves are arranged on the surface of the seedling removal rollers 51. The grooves are irregular in shape and distributed on the entire seedling removal rollers 51, so as to wrap and separate the mixed seedlings. The seedling prevention plate 52 is arranged behind the seedling removal rollers 51, and the lower edge of the seedling prevention plate 52 is lower than the upper edge of the lower seedling removal roller 51, and the seedling prevention plate 52 is made of flexible material. The two seedling removal rollers 51 roll relative to each other from outside to inside on the side facing the potato guide plate 44 to separate the seedlings from the potatoes. The separated potatoes fall into the collection box 12 after passing through the seedling prevention plate 52.

[0029] A method for calculating the force on potatoes, wherein the potatoes move in the above-mentioned potato picking device, and the calculation method comprises the following steps: A1. Figure 5 and Figure 6 As shown in the figure, when the potato is driven to the top of the potato guide ring 424 by the picking claw 431, the hinge point at the end of the picking claw 431 is defined as point A, the hinge point in the middle of the picking claw 431 is defined as point B, the rotation center of the potato is point O, the rotation center of the potato guide ring 424 is point O, and the potato guide ring 424 rotates at an angular velocity Rotate at a constant speed; A2. Kinematic analysis of the potato and the potato guide mechanism yields (1) In the formula is the velocity of point B, m / s; is the velocity of point A, m / s; is the speed of point B relative to point A, m / s; is the velocity of point C relative to point A, m / s; is the velocity of point C relative to point B, m / s; A3. Figure 7 As shown, according to the vector diagram method, we can get (2) (3) (4) (5) (6) (7) (8) Where: l AO is the distance from point A to point O, m; is the angular velocity of the AO segment; α is the angle between the velocity direction of point A and the velocity direction of point B, °; β is the angle between the velocity direction of point A and the velocity direction of point B relative to point A, °; γ is the angle between the velocity direction of point B relative to point A and the velocity direction of point C relative to point A, °; ζ is the angle between the velocity direction of point C and the horizontal line, °; V Cx is the horizontal velocity of point C, m / s; V Cy is the vertical velocity of point C, m / s; A4. Perform kinematic analysis on the falling process of potatoes, such as Figure 8 and Fig. 9 As shown, point D is defined as the initial contact point between the potato and the potato guide ring 424 during the falling process, point E is defined as the final contact point between the potato and the potato guide ring 424, and segment DE is an arc with a radius of R DE Point F is the first contact point between the potato and the potato guide plate 44, point G is the first connection point on the potato guide plate 44, and segment FG is an arc with a radius of R FG Point H is the second connection point of the potato guide plate 44, segment GH is a straight line, point I is the third connection point of the potato guide plate 44, and point I is the lowest point of the potato guide plate 44, segment HI is an arc with a radius of R HI , point J is the final contact point between the potato and the potato guide plate 44, and segment IJ is a straight line; a rectangular coordinate system is established with point O as the center and OC as the Y axis, then the motion trajectory equation of the potato is: (9) The equations of each line segment are: The expression of arc DE segment: (10) The expression of the horizontal line EF segment is: (11) The expression of arc FG segment: (12) The expression of the oblique straight line GH segment is: (13) The expression of arc HI segment is: (14) The expression of the oblique straight line IJ segment is: (15) The piecewise function of the potato's moving trajectory on each curve segment is obtained as follows: (16) Where t is the time of potato movement, s; l D , l E , l F , l G , l H , l I , l J are the horizontal coordinates of each point, m; h C 、h D 、h E 、h F 、h G 、h H 、h I 、h J are the ordinates of each point, m; l DE , l FG , l HI are the horizontal coordinates of the centers of arcs DE, FG, and HI, m; h DE 、h FG 、h HI are the ordinates of the centers of arcs DE, FG, and HI, respectively, in m; A5. Analyze the force on the potato during its fall, such as Fig.10As shown in FIG. 1 , when the potato falls onto the potato guide ring 424 or the potato guide plate 44, the potato and the potato guide plate or the potato guide ring begin to contact and generate elastic force, and the acceleration is approximately linear with time. The acceleration gradually increases with the increase of the collision time. When the potato is no longer compressed, its elastic deformation gradually recovers, and the acceleration gradually decreases until it is reduced to 0 and completes the recovery. In this process, the potato is subjected to the normal reaction force and friction force of the potato guide ring 424 or the potato guide plate 44, where the normal reaction force is (17) Wherein v0 is the speed of the potato when it just contacts the potato guide ring 424 or the potato guide plate 44, m / s; θ is the angle between the speed of the potato when it just contacts the potato guide ring 424 or the potato guide plate 44 and the tangent line of the contact point, °; F N is the normal reaction force of the contact surface between the potato and the potato guide ring 424 or the potato guide plate 44, N; From the beginning of the collision to the maximum compression state of the potato, the normal reaction force F N From zero to the maximum value F Nm ,but (18) (19) (20) (twenty one) (twenty two) (twenty three) (twenty four) (25) (26) (27) Where λ is the angle between the tangent line of the contact point of the potato just contacting the potato guide ring 424 or the potato guide plate 44 and the horizontal line, °; φ is the angle between the speed of the potato just contacting the potato guide ring 424 or the potato guide plate 44 and the horizontal line, °; F f is the friction force when the potato contacts the potato guide ring 424 or the potato guide plate 44, N; Δt is the time from the start of collision to the maximum compression state, s; R s is the average radius of the potato, m; m is the mass of the potato, kg; F m v is the maximum resultant force on the potato when it contacts the potato guide ring 424 or the potato guide plate 44, N; x v is the horizontal velocity of the potato when it just contacts the potato guide ring 424 or the potato guide plate 44, m / s; v yis the vertical speed of the potato when it just contacts the potato guide ring 424 or the potato guide plate 44, m / s; μ is the friction coefficient of the potato guide ring 424 or the potato guide plate 44.

[0030] By consulting relevant literature, we can find that the ultimate destructive force of potato is 86.76N. Let the ultimate destructive force of potato be F 极 The instantaneous force F exerted on the potato when it falls onto the potato guide plate or potato guide ring is m Should be less than F 极 By adjusting the position of the highest point in the potato transmission path, the instantaneous force F m Should be less than F 极 , thereby avoiding damage to potatoes.

[0031] When the speed of the potato picker increases while the speed of the potato guide mechanism remains unchanged, potatoes will accumulate, causing the working efficiency of the potato picker to decrease. When the speed of the potato picker slows down while the speed of the potato guide mechanism remains unchanged, it will cause a waste of power resources of the potato picker. In addition, the potato picker needs to work in a complex and changeable working environment. It will be affected by a combination of soil conditions (clay and sandy loam), terrain conditions (plains, hills and mountains) and plot yields, resulting in different working environments for the potato picker, which will have a significant impact on the working efficiency of the potato picker collection device.

[0032] A potato picking device adaptive control method, using the above-mentioned potato picking device, such as Figures 11 to 14 As shown, the following steps are included: B1. Periodically collect the potato guide ring speed V0 and the potato guide mechanism torque T0 of the picking device; the potato guide mechanism torque T0 can be measured by installing a torque sensor on the potato guide shaft 421 or other components, or the total torque of the potato guide mechanism can be obtained by partial measurement and calculation.

[0033] (28) In the formula The torque generated by the potato-soil mixture on the picking claw 431 on the potato guide shaft 421 is is the torque generated by the picking claw 431 on the potato guide shaft 421, is the torque generated by the rotating frame 422 on the guide shaft 421, The torque generated by the friction between the guide shaft 421, the bearing and the bearing seat during the rotation process; B2. Determine whether the torque T0 is within a preset range; if not, proceed to step C1; if within the preset range, proceed to step D1; C1. Input the collected potato ring speed V0 and potato mechanism torque T0 into the first BP neural network to calculate the potato ring speed V1 at the next moment; C2. The speed of the potato ring V1 is input into the PID controller, and the PID controller outputs the adjusted speed of the potato ring V1. The system input r(k) and system output y of the PID controller out (k) and the system error e(k) are input into the second BP neural network, and the integral adjustment coefficient, proportional adjustment coefficient and differential adjustment coefficient of the adjusted PID controller are calculated and output by the second BP neural network; C3. Collect the torque T1 at the next moment and proceed to step B2; D1. Record the collected potato guide ring speed V0 and potato guide mechanism torque T0 as a set of data; D2. When the data sample records are full of 10 groups, the data set is updated by cyclic overwriting; D3. The updated data set is input into the first BP neural network for training, and the weight of the first BP neural network is updated.

[0034] The adaptive system included in this solution includes a learning system and a control system. The learning system includes training of the first BP neural network to fit the functional relationship of the key indicators of the current operating environment, and the control system is used to adjust the output speed V1 of the guide ring each time.

[0035] The initial data set of the learning system in the adaptive system contains 200 sets of data samples, and the data set is randomly divided into a training set and a validation set at a ratio of 8:2. Since there may be too few successful adjustment samples in the initial stage of adaptation and even in the early stage, the conditions for updating the data set cannot be triggered. Therefore, in the initial stage of adaptation, the allowable variation range of the preset torque of the guide mechanism is increased to a times the rated allowable variation range. Each time the data set is updated, the allowable variation range of the torque of the guide mechanism is reduced proportionally until the allowable variation range of the torque of the guide mechanism is reduced to the rated allowable variation range after the data set is updated 20 times, and the initial data set is completely covered.

[0036] The present invention is described above by way of examples, but the present invention is not limited to the above specific embodiments, and any changes or modifications made based on the present invention belong to the scope of protection claimed by the present invention.

Claims

1. A potato picking device, characterized in that: The invention comprises a shell (11), a shovel blade (21) is arranged at the front bottom of the shell (11), a potato-pulling mechanism and a potato-guiding mechanism are arranged in sequence from front to back in the shell (11), a collecting box (12) is arranged behind the potato-guiding mechanism, the collecting box (12) is fixedly connected to the shell (11) and communicates with the internal space of the shell (11); the potato-pulling mechanism is arranged above the shovel blade (21) and transfers potatoes on the shovel blade (21) to the potato-guiding mechanism; the potato-guiding mechanism comprises a potato-guiding wheel (411), a potato-guiding ring (424), a picking claw (431) and a potato-guiding plate (44); the potato-guiding wheel (411) is fixedly arranged on the shell (11), a sliding groove (412) is arranged on the potato-guiding wheel (411), a plurality of potato-guiding rings (424) are provided, the potato-guiding rings (424) rotate synchronously and are arranged coaxially with the potato-guiding wheel (411), the picking claws (431) and the potato-guiding rings (424) are arranged alternately, and the potato-guiding rings (431) and the potato-guiding rings (431) are arranged interlaced with each other. 24) is fixedly connected to the rotating frame (422), the end of the picking claw (431) is hinged on the rotating frame (422), the middle of the picking claw (431) is hinged to the roller (432), the roller (432) is clamped in the slide groove (412) and moves along the slide groove (412), the potato guide plate (44) is arranged between the potato guide ring (424) and the collection box (12), and the height of the potato guide plate (44) is gradually reduced; the picking claw (431) After the rear side passes the potato guide plate (44), it gradually extends outward and rotates toward the bottom. When the picking claw (431) reaches the bottom of the potato guide ring (424), it is fully extended. When the picking claw (431) rotates upward from the front side to the upper side of the potato guide ring (424), it begins to retract into the potato guide ring (424) until it reaches the potato guide plate (44) and retracts to the limit position. At this time, the rear edge line of the picking claw (431) does not exceed the front edge line of the potato guide plate (44).

2. A potato picking device according to claim 1, characterized in that: The potato guide plate (44) is composed of a plurality of strip structures, which are arranged in parallel in the horizontal direction, and the picking claws (431) are correspondingly arranged at intervals between adjacent strip structures.

3. A potato picking device according to claim 1, characterized in that: The potato guide mechanism further comprises a potato guide shaft (421), the rotating frame (422) is fixedly connected to the potato guide shaft (421) and rotates synchronously, a connecting frame (423) is fixedly arranged between the end of the rotating frame (422) and the potato guide ring (424), a hinged rod is fixedly arranged between the ends of adjacent connecting frames (423), the hinged rod is coaxially arranged, the end of the picking claw (431) is hinged on the hinged rod, a connecting rod (433) is arranged through the middle of the picking claw (431) close to the hinged rod, and the roller (432) is rotatably arranged at the end of the connecting rod (433).

4. A potato picking device according to claim 1, characterized in that: The potato-pushing mechanism comprises a potato-pushing wheel (31), a potato-pushing roller (32) and a potato-pushing shaft (33); the potato-pushing wheel (31) is fixedly connected to both ends of the potato-pushing shaft (33) and rotates synchronously with the potato-pushing shaft (33); the potato-pushing roller (32) is fixedly connected between the potato-pushing wheels (31) and is parallel to the potato-pushing shaft (33); the potato-pushing roller (32) is multiple in number and is evenly distributed along the circumferential direction at the edge of the potato-pushing wheel (31).

5. A potato picking device according to claim 1, characterized in that: The potato-pulling mechanism further comprises a potato-pulling driving mechanism (34), and the potato-guiding mechanism further comprises a potato-guiding driving mechanism (45), and the potato-pulling driving mechanism (34) and the potato-guiding driving mechanism (45) move synchronously.

6. A potato picking device according to claim 1, characterized in that: A seedling removal mechanism is arranged between the potato guide mechanism and the collecting box (12), the seedling removal mechanism comprising a seedling removal roller (51) and a seedling blocking plate (52), the seedling removal roller (51) being arranged at the end of the potato guide plate (44) and parallel to the axis of the potato guide ring (424), the seedling removal rollers (51) being arranged in pairs along the longitudinal direction and rolling relative to each other, the surface of the seedling removal rollers (51) being provided with grooves, the seedling blocking plate (52) being arranged behind the seedling removal rollers (51), the lower edge of the seedling blocking plate (52) being lower than the upper edge of the lower seedling removal roller (51), and the seedling blocking plate (52) being made of a flexible material.

7. A potato picking device according to claim 1, characterized in that: The upper side of the shovel blade (21) is fixedly provided with shovel teeth (22), the number of which is plural, and the shovel teeth (22) are provided protruding from the surface of the shovel blade (21), the front end of the shovel teeth (22) is conical, and is provided protruding from the front end of the shovel blade (21); the rear of the shovel blade (21) is fixedly connected with a grid bar (23), the grid bar (23) extends from front to rear to the bottom of the potato guide mechanism, the number of which is plural, and intervals are provided between adjacent grid bars (23).

8. A method for calculating the force on potatoes, characterized in that: The potatoes are moved in a potato picking device according to any one of claims 1 to 7, and the calculation method comprises the following steps: A1. When the potato is driven to the top of the potato guide ring (424) by the picking claw (431), the hinge point at the end of the picking claw (431) is defined as point A, the hinge point in the middle of the picking claw (431) is defined as point B, the rotation center of the potato is point O, the rotation center of the potato guide ring (424) is point O, and the potato guide ring (424) rotates at an angular velocity of Rotate at a constant speed; A2. Kinematic analysis of the potato and the potato guide mechanism yields （1） In the formula is the velocity of point B, m / s; is the velocity of point A, m / s; is the speed of point B relative to point A, m / s; is the velocity of point C relative to point A, m / s; is the velocity of point C relative to point B, m / s; A3. According to the vector diagram method, we can get （2） （3） （4） （5） （6） （7） （8） Where: l AO is the distance from point A to point O, m; is the angular velocity of the AO segment; α is the angle between the velocity direction of point A and the velocity direction of point B, °; β is the angle between the velocity direction of point A and the velocity direction of point B relative to point A, °; γ is the angle between the velocity direction of point B relative to point A and the velocity direction of point C relative to point A, °; ζ is the angle between the velocity direction of point C and the horizontal line, °; V Cx is the horizontal velocity of point C, m / s; V Cy is the vertical velocity of point C, m / s; A4. Perform kinematic analysis on the falling process of the potato, define point D as the initial contact point between the potato and the potato guide ring (424) during the falling process, point E as the final contact point between the potato and the potato guide ring (424), and segment DE as an arc with a radius of R. DE Point F is the first contact point between the potato and the potato guide plate (44), point G is the first connection point on the potato guide plate (44), and segment FG is an arc with a radius of R. FG , point H is the second connection point of the potato guide plate (44), segment GH is a straight line, point I is the third connection point of the potato guide plate (44), and point I is the lowest point of the potato guide plate (44), segment HI is an arc with a radius of R HI , point J is the final contact point between the potato and the potato guide plate (44), segment IJ is a straight line; a rectangular coordinate system is established with point O as the center and OC as the Y axis, then the motion trajectory equation of the potato is: （9） The equations of each line segment are: The expression of arc DE segment: (10) The expression of the horizontal line EF segment is: (11) The expression of arc FG segment: (12) The expression of the oblique straight line GH segment is: (13) The expression of arc HI segment is: (14) The expression of the oblique straight line IJ segment is: (15) The piecewise function of the potato's moving trajectory on each curve segment is obtained as follows: （16） Where t is the time of potato movement, s; l D , l E , l F , l G , l H , l I , l J are the horizontal coordinates of each point, m; h C 、h D 、h E 、h F 、h G 、h H 、h I 、h J are the ordinates of each point, m; l DE , l FG , l HI are the horizontal coordinates of the centers of arcs DE, FG, and HI, m; h DE 、h FG 、h HI are the ordinates of the centers of arcs DE, FG, and HI, respectively, in m; A5. The force applied to the potato during the falling process is analyzed. When the potato falls onto the potato guide ring (424) or the potato guide plate (44), the potato is subjected to the normal reaction force and friction force of the potato guide ring (424) or the potato guide plate (44). The normal reaction force is （17） Wherein v0 is the speed of the potato when it just contacts the potato guide ring (424) or the potato guide plate (44), m / s; θ is the angle between the speed of the potato when it just contacts the potato guide ring (424) or the potato guide plate (44) and the tangent line of the contact point, °; F N is the normal reaction force of the collision contact surface between the potato and the potato guide ring (424) or the potato guide plate (44), N; From the beginning of the collision to the maximum compression state of the potato, the normal reaction force F N From zero to the maximum value F Nm ,but （18） （19） （20） （21） （22） （23） （24） （25） （26） （27） Wherein λ is the angle between the tangent line of the potato at the contact point when the potato just contacts the potato guide ring (424) or the potato guide plate (44) and the horizontal line, °; φ is the angle between the speed of the potato when it just contacts the potato guide ring (424) or the potato guide plate (44) and the horizontal line, °; F f is the friction force when the potato contacts the potato guide ring (424) or the potato guide plate (44), N; Δt is the time from the start of collision to the maximum compression state, s; R s is the average radius of the potato, m; m is the mass of the potato, kg; F m is the maximum resultant force on the potato when it contacts the potato guide ring (424) or the potato guide plate (44), N; v x v is the horizontal velocity of the potato when it just contacts the potato guide ring (424) or the potato guide plate (44), m / s; v y is the vertical speed of the potato when it first contacts the potato guide ring (424) or the potato guide plate (44), m / s; μ is the friction coefficient of the potato guide ring (424) or the potato guide plate (44).

9. A method for adaptively controlling a potato picking device, characterized in that: Using the potato picking device according to any one of claims 1 to 7 comprises the following steps: B1. Periodically collect the potato guide ring speed V0 and the potato guide mechanism torque T0 of the picking device; B2. Determine whether the torque T0 is within a preset range; if not, proceed to step C1; if within the preset range, proceed to step D1; C1. Input the collected potato ring speed V0 and potato mechanism torque T0 into the first BP neural network to calculate the potato ring speed V1 at the next moment; C2. The speed V1 of the guide potato ring is input into the PID controller, and the PID controller outputs the adjusted speed V1 of the guide potato ring. The system input, system output and system error of the PID controller are input into the second BP neural network, and the integral adjustment coefficient, proportional adjustment coefficient and differential adjustment coefficient of the adjusted PID controller are calculated and output by the second BP neural network; C3. Collect the torque T1 at the next moment and proceed to step B2; D1. Record the collected potato guide ring speed V0 and potato guide mechanism torque T0 as a set of data; D2. When the data sample records are full of 10 groups, the data set is updated by cyclic overwriting; D3. The updated data set is input into the first BP neural network for training, and the weight of the first BP neural network is updated.

10. The adaptive control method of a potato picking device according to claim 9, characterized in that: The initial data set of the adaptive system contains 200 groups of data samples, and the data set is randomly divided into training set and validation set in the ratio of 8:2; in the initial stage of adaptation, the allowable variation range of the preset torque of the guide mechanism is increased to a times the rated allowable variation range, and each time the data set is updated, the allowable variation range of the torque of the guide mechanism is reduced proportionally until the allowable variation range of the torque of the guide mechanism is reduced to the rated allowable variation range after the data set is updated 20 times, and the initial data set is completely covered.

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