Abstract:
An apparatus and method is presented for separating healthy plants from agricultural material, such as harvested plants. The apparatus includes a conveyor to present the agricultural material to a mesh, which may be, for example bristles. A rotating drum with a plurality of protruding tines moves through the mesh and pulls individual plants from the agricultural material. A machine vision system may then sort the healthy, individual plants. The method includes presenting the agricultural material to the mesh, and then pulling individual plants through the mesh.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit under U.S.C. §119(e) to pending U.S. Provisional Application No. 61/869,026, filed Aug. 22, 2013, the contents of which are hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention generally relates to agricultural equipment, and more particularly to a method and system for separating plants having intertwined roots. 
         [0004]    2. Discussion of the Background 
         [0005]    Plants are sometimes raised at nurseries and then transplanted for growing in farms. Strawberries are an example of a crop that is raised this way. Thus, for example, a field of strawberries is grown for a certain period of time, the plants are harvested and packaged for sale as individual plants. 
         [0006]    Often, the roots of adjacent plants become intertwined. The manual separation of individual plants is performed manually, and is very labor intensive. In addition, some plants may not be healthy enough to survive transplantation. These plants need to be separated and not sold for transplanting. 
         [0007]    There exists a need for a machine and method that can process large quantities of harvested plants and separate them into individual plants. Such a machine and method should be highly automated and be capable of separating the plants without damaging the roots. It would also be advantageous to be able to also eliminate plants that do not seem healthy enough to survive transplanting. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    The present invention includes a machine (a “singultor”) that can process a large quantity of agricultural material that has been harvested. The agricultural material may include individual plants, clumps of intertwined plants, damaged plants, soil, rocks, and other waste material. The machine includes a conveyor that delivers agricultural material to a device that can provide individual, healthy plants. In one embodiment, the plants are placed on a conveyor and are delivered to a “hold-back device,” which may include a mesh such as a row of wires, rubber flaps, or bristles through which the plants are pulled. On the opposite side of hold-back device, a pull-through device includes numerous tines which rotate through the mesh and pull individual or clumps of intertwined plants through the mesh. The tines, for example and without limitation, may move through the mesh and pull plants through the hold-back device. When the plants are pulled, by the tines, through the mesh, individual plants may be separated from intertwined clumps of plants. The plants then pass through a machine vision system which isolates healthy, individual plants from damaged plants, intertwined plants that were not successfully or only partially separated, and waste. Any plants that are still intertwined plants may then be returned to the conveyor in an attempt to separate the plants. 
         [0009]    One embodiment of the invention provides an apparatus having a first portion to accept agricultural material and a second portion to provide individual plants from the agricultural material. The apparatus includes: a conveyor having a first conveyor end at the first portion and a second conveyor end; a mesh having a first side contacting the second conveyor end and a second side opposing the second conveyor end; and a pull-through device at the second portion, where the pull-through device includes a plurality of tines, and where the pull-through device moves the plurality of tines through the mesh. When the conveyor moves accepted agricultural material from the first portion to the first side of the mesh, and the plurality of tines moves through the mesh to separate individual plants from agricultural material at the first side and provide individual plants at the second side. 
         [0010]    Another embodiment of the invention is a method for processing agricultural material using an apparatus having a first portion to accept agricultural material and a second portion to provide individual plants from the agricultural material. The apparatus includes: a conveyor having a first conveyor end at the first portion and a second conveyor end; a mesh having a first side contacting the second conveyor end and a second side opposing the second conveyor end; and a pull-through device at the second portion, where the pull-through device includes a plurality of tines, and where the pull-through device moves the plurality of tines through the mesh. When the conveyor moves accepted agricultural material from the first portion to the first side of the mesh, and the plurality of tines moves through the mesh to separate individual plants from agricultural material at the first side and provide individual plants at the second side. 
         [0011]    Yet another embodiment of the present invention provides a method for processing agricultural material. The method includes: providing two or more intertwined plants to a first side of a mesh; and pulling individual plants from the two or more intertwined plants through the mesh. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0012]      FIG. 1  is side view of one embodiment of a device for separating plants; 
           [0013]      FIG. 2  is a top view of one embodiment of a singultor; 
           [0014]      FIG. 3  is a sectional side view  3 - 3  of  FIG. 2 ; 
           [0015]      FIG. 4  is a perspective detail view of the singultor of  FIG. 2 ; 
           [0016]      FIG. 5  is a side view  3 - 3  of  FIG. 2  showing material being transported through the inventive device; 
           [0017]      FIGS. 6A ,  6 B, and  6 C are sequential, detailed side views showing material being transported by the pull-through unit through the hold-back unit; 
           [0018]      FIG. 7  is a detailed perspective view of one embodiment of the conveyor belt of  FIG. 2 ; and 
           [0019]      FIG. 8  is a detailed perspective view of one embodiment of the tines of the pull-through device of  FIG. 2 . 
       
    
    
       [0020]    Reference symbols are used in the Figures to indicate certain components, aspects or features shown therein, with reference symbols or labels common to more than one Figure indicating like components, aspects or features shown therein. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0021]      FIG. 1  is side view of one embodiment of a device  10  for processing agricultural material into individual plants. In general, the agricultural material may include plants, clumps of plants which their roots intertwined, and waste (damaged plants, dirt, rocks, etc.). Device  10  includes a separating unit, or singulator  100  having a frame  102 , a front end  101  for accepting agricultural material and a back end  103  to provide separated agricultural material. The separated material may then be provided to a sorting system  20  that can identify and sort individual plants from the other agricultural material. Sorting system  20  may, for example and without limitation, include a conveyor  21  for accepting material from back end  103 , a camera  22 , a computer  30 , and sorting jets  23  which may direct material into a first bin  24   a,  a second bin  24   b,  or a third bin  24   b.  Computer  101  may also control singulator  100 , with or without sorting system  20 , by adjusting the speed or other settings of the singulator. 
         [0022]    Sorting system  20 , while not necessarily part of the present invention, is shown, for example and without limitation, as being accomplished by a machine vision system that includes a Computer, a Camera, and Sorting Jets. In general, a large quantity of material is delivered by the Singulator including: 1) individual, healthy plants; 2) possible clumps of plants that were not successfully separated in the Singulator; and 3) waste that includes plant parts, plants with unhealthy roots, rocks, and/or soil. In the machine vision system, computer  30  processes images from camera  22 . 
         [0023]    Sorting system  20 , while not necessarily part of the present invention, is well known, and is shown, for example and without limitation, as a machine vision sorting system, such as the system described in U.S. Patent Application Publication No. 2013/0028487, the contents of which are hereby incorporated by reference. Sorting system  20  may, for example, include a neural network algorithm that determines, based on training, to recognize individual, healthy plants. Such training may be accomplished by providing sorting system  20  with material of known condition. Thus, for example, the algorithm of sorting system  20  may have a training mode, where the system is presented with materials of known condition (healthy, single plants, multiple plants, etc.) and informed of their condition. 
         [0024]    Sorting system  20  may, for example, include programming in computer  30  to process images from camera  22  to classify material on conveyor  22  as being: a single health plant, a clump of two or more plants, or waste material, including plants with damaged roots, dirt, rocks, or other waste material. The classification of material may, for example and without limitation, be done by “training” software in computer  30  using known material—that is known good plants and waste material are sent through sorting system  20 , and the system can thus be trained to classify the material. As the material travels to the end of conveyor  21 , jets  23  may be instructed from computer  30  to issue jets of air that deflect the material into one of bins  24   a,    24   b,  or  24   c  based on their classification where, for example and without limitation, bin  24   a  is for healthy, single plants, bin  24   b  is for material that may contain unseparated, healthy plants, and bin  24   c  is for waste material. Healthy plants in bin  24   a  may then be packaged, multiple plants from bin  24   b  may be sent through the singulator  100  for re-processing, and waste material in bin  24   c  may be disposed of 
         [0025]      FIGS. 2 and 3  show one embodiment of singulator  100 , where  FIG. 2  is a top view of one embodiment of the singulator, and  FIG. 3  is a sectional side view  3 - 3  of  FIG. 2 . 
         [0026]    Singular  100  has a width W and includes a horizontal section  202  having a length L 1  and which includes front end  101 , and an incline section  204  having a length L 2  and which includes back end  103 . Incline section  204  extends up an angle α, as shown in  FIG. 3 , which may be, for example, from 20 to 30 degrees. A conveyor system  210  extends between front end  101  and back end  103 , and includes a conveyor belt  211 , several rollers  213 ,  215 , and  217  to guide the belt, and a drive gear or roller  219  connected to a drive motor  214  to provide power for moving conveyor belt  211 . Rollers  213 ,  215 ,  217 , and  219  are rotatably mounted to frame  102 . 
         [0027]    In one embodiment, width W is 1.815 m, L 1  is 2.7 m, and L 2  is 2.9 m. Drive motor  214  may be, for example, a 1 HP, 3 Phase 1750 RPM motor with a 645:1 right angle thru shaft gearbox (NORD Gear Corp, Waunakee Wis.). Conveyor belt  211  includes vertical protrusions  212  to urge the movement of agricultural material. Protrusions  212  are also referred to herein, without limitation, as pins or pegs. Belt  221 , which may include one or more belts, is also referred to as a “pegged belt”  211 . For the sake of clarity of the drawing, only three rows of pins  212  are shown. Pins  212  may be provided in a regular pattern along the length of conveyor belt  211 . 
         [0028]    One example of a section of conveyor belt  211  is shown, for example and without limitation, in  FIG. 7 , in which conveyor belt  211  is shown as having belts  703 , which run the length of the conveyor belt, and cross members  701  which run between belts  703 . Belt  703  may be, for example and without limitation, a belted chain link belt. Pins  212  are shown and protruding a distance h on every other cross member  701 . In one embodiment, h is 0.04 m (1.5 inches). 
         [0029]    In certain embodiments, the speed of drive motor  214  is controlled by computer  30 , and preferable moves conveyor belt  211  at a speeds of from 1 m/min to 5 m/min or approximately 3 m/min. 
         [0030]    A rake-back unit  220  is positioned on top of conveyor belt  211  in incline section  202 . Rake-back unit  220  includes a housing  222  that is movably attached to frame  102 , and which supports a rotatable drive gear  225  powered by a motor  227  and a roller  223 . Rake-back unit  220  also includes a rake-back belt  221  which extends between drive gear or roller  225  and roller  223 . Belt  221  may be, for example and without limitation, similar to belt  211  having a chain link belt and protruding pins  229 . For the sake of clarity of the drawing, only three rows of pins  229  are shown. 
         [0031]    In one embodiment, drive motor  227  may be, for example, a 1 HP, 3 Phase 1750 RPM motor with 50:1 thru shaft gear box (NORD Gear Corp, Waunakee Wis.). Belt  221  maybe a belted chain with vertical protrusions to urge the movement of agricultural material. In certain embodiments, the speed of drive motor  227  is controlled by computer  30 , and preferably moves belt  221  as speeds of from 0.1 m/s to 1 m/s. In certain embodiments the drive rollers  219  and  225  rotate in the same direction. In other embodiments drive rollers  219  and  225  rotate in opposite directions useful, for example, in freeing material that may get caught in the belts. 
         [0032]    Housing  222  is attached to frame  102  at a hinge  233  on one housing end and, through a pivot  228  to an adjustable actuator  224  that is attached to the frame at a hinge  226 . Actuator  224  may be, for example and without limitation, an electrical actuator that has a length that is controllable by computer  30 . 
         [0033]    A hold-back unit  250  is positioned between rake-back unit  220  and a pull-through unit  260 , which includes a roller  261  having a plurality of radially projecting flaps or tines  263 , and is rotatably attached to frame  102  and driven by a motor  265 . 
         [0034]    In one embodiment, motor  265  may be, for example a 3 HP, 3 Phase 1750 RPM motor with 40:1 thru shaft gearbox (NORD Gear Corp, Waunakee Wis.). Roller  261  may rotate at speed of from 10 to 70 RPM. Tines  263  are long enough to pass through hold back unit  250  to interact with agricultural material on conveyor belt  211 . In certain embodiments the drive rollers  219  and  261  rotate in the same direction, and in other embodiments drive rollers  219  and  261  rotate in opposite directions. 
         [0035]    In one embodiment, tines  263  are flexible torsion springs which return to their original orientation, approximately perpendicular to roller  261  when not in contact with objects or material. Thus, for example there may be 18 rows of tines along different radial axis, and they may be spaced 1 to 3 cm along the length of roller  261 . 
         [0036]      FIG. 4  is a perspective detail view of the singulator of  FIG. 2 . In the view of  FIG. 4 , roller  261  has end caps  401  which support rods  403  and pipes  405 . Each pipe  405  supports one row of tines  263 , which protrude from roller  261 . 
         [0037]    In one embodiment, roller  261  has a radius of 0.18 m (7 inches) about axis  265 , pipes  405  are positioned a distance of 0.20 m (8 inches) from the axis, and the tips of tines  263  rotate about a distance of 0.5 m (20 inches) from the axis. 
         [0038]    Hold-back unit  250  includes a mesh  251  that contacts conveyor belt  211  and which may be formed from a plurality of strips that are closely spaced. The relative placement of hold-back unit  250  and pull-through unit  260  is such that tines  263  pass through mesh  251 —that is, as roller  261  rotates about an axis  267 , tines  263  pass through mesh  251 . In one embodiment, tines  263  are metal, and may be, for example and without limitation tines that are fixed to roller  261 , or torsion springs that are attached to roller  261 , and mesh  251  is plastic, which may be, for example and without limitation, a polypropylene 12 inch (0.3 m) strip brush, such as is used in street sweepers. In another embodiment, mesh  251  may be replaced with strips of rubber. 
         [0039]      FIG. 8  is a detailed perspective view of one embodiment of tines  263 , which show that each tine  263  includes a torsion spring  801  which is attached to bar  403  by a bolt  803 . In one embodiment, tines  263  are formed from spring steel. It is preferred that the orientation of torsion spring is such that, as tines  263  rotate through hold-back unit  250 , the tines move in the direction indicated by the arrow, such that the spring is compressed, and then returns to the original orientation. In certain embodiments, the straight, protruding portions of tines  263  are between 0.05 m (2 inches) and 0.1 m (4 inches) long, and the curled, spring portion has a diameter of approximately (0.025 m) 1 inch. 
         [0040]      FIG. 4  also shows conveyor system  210  and guiding portion  220 . As discussed subsequently, material is conveyed between conveyor belt  211  of conveyor system  210  and belt  221  of rake-back  220  to hold back unit  250 . 
         [0041]    The operation of singulator  200  is shown  FIG. 5 , which is a side view  3 - 3  of  FIG. 2  showing material being transported through the inventive device. As shown in  FIG. 5 , singulator  100  accepts agricultural material M on conveyor belt  211  and, as indicated by arrow B, the motion of roller  219 , moves the material as indicated by arrow A. The material moves up incline section  204 , where it may contact belt  221  of rake-back unit  220 . A height H provides the maximum height of material M above conveyor belt  211  which may move towards hold-back unit  250 . The length of actuator  224 , which may be controlled by computer  30 , causes rake-back unit  220  to rotate about pivot  228 , as indicted by arrow C. As shown by arrow D, drive rollers  225  may rotate to hold back material M on belt  221 , or to accelerate the material along the belt. 
         [0042]    Hold-back unit  250  prevents agricultural material M from passing through singulator  100  by retaining the material on one side of the old-back unit  250 .  FIGS. 6A ,  6 B, and  6 C, are sequential, detailed side views showing material being transported by the pull-through unit  260  through the hold-back unit  250 . As shown in  FIG. 6A , agricultural material M is transported on conveyor belt  211  towards hold back unit  250 . As shown in  FIG. 6B . tines  263  rotate through mesh  251  and contacts agricultural material M, which may also be restrained by pins  212 .  FIG. 6C  shows tines  263  having pulled a single plant S from agricultural material M, which may then pass through sorting system  20 . 
         [0043]    It is preferred that the force placed on agricultural material M, as in  FIGS. 6A-6C  results in at least some intertwined plants being separated, and thus individual plants being delivered to belt  21 . 
         [0044]    It is important that the various component of singulator  100 , and specifically those of rake-back unit  220 , hold-back unit  250 , and pull-through unit  260  be sized and operated to pull apart plants with intertwined roots without damaging healthy roots. 
         [0045]    The dimensions, sizes and speeds of the components of singulator  100  to accomplish singulating plants depends on factors such as the type of plants, the maturity of the plants, and how they were planted, to name a few. While some plants may be separated, and others may be damaged, the inventors have shown that it is possible to separate, or “singulate” in the inventive device. 
         [0046]    In certain embodiments, the speed of the various motors and actuators of singulator  100  will be controlled by computer  30  utilizing information from sorting system  20 . Thus, for example, the rotational speed of pull-through unit  260  and/or height h may be adjusted if not enough plants are singulated, or if too many plants are being damaged in the singulator. This control may be accomplished by a feedback loop that will control the speeds of motors  214 ,  227 , and  265 , and the length of actuator  224 . The motor speeds may be regulated, for example and without limitation, through separate variable frequency drives are linked to a programmable logic controller, which is in communication with computer  30 . Additionally, sensors, such as proximity switches, which may be provided that sense the overload of too much material against hold-back unit  250 , and which may slow down or stop singulator  100 . 
         [0047]    It should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention. 
         [0048]    Thus, while there has been described what is believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention.