Abstract:
In an aspect, a process for removing a tail end of Brussels sprouts comprises separating a Brussels sprout from a stack and transferring it to a longitudinal transport track. On the track, the Brussels sprout is manipulated to position a longest dimension of the Brussels sprout perpendicular to a direction of travel of the transport track. Near an end of the track, a position and an orientation of each Brussels sprout is defined by photographic detection. Each Brussels sprout is removed from the transport track by a gripper. A position and an orientation of the gripper are defined using the detected position and orientation of the Brussels sprout to be removed. The gripper is re-oriented and moved along a knife to remove the tail end of the Brussels sprout. The Brussels sprout is removed from the gripper and collected.

Description:
CROSS REFEFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of PCT/EP2010/001187, filed internationally on Feb. 26, 2010, all subject matter disclosed therein is incorporated by reference in its entirety herein for all purposes. 
     
    
     BACKGROUND 
       [0002]    The following relates to a process for removing the tail end of Brussels sprouts. A process for removing the tail end of Brussels sprouts has been described in Dutch patent application 7504554. 
         [0003]    In this known process the Brussels sprouts are transported on the upper horizontal part of two parallel endless belts, which horizontal part is mounted above a number of rotating knives which can cut off the tail end of a Brussels sprout if the same is protruding through the gap between the two endless belts. In order to make sure that a Brussels sprout will have its tail end protruding through the gap between the belts; these belts are moving with different velocity thereby generating a rolling movement on the Brussels sprout. Otherwise there is provided an agitating member which will act on the Brussels sprout in order to change its position. In this way most of the Brussels sprouts will have their orientation changed so that at least once during the each Brussels sprout rests on the belts its tail end is protruding through the gap between the belts and cut off. 
         [0004]    With this type of process satisfactory results have been obtained although the cutting operation was relatively rough and in general the cut off part was larger than actually needed for the Brussels sprout being acceptable for consumption. Moreover in the last years the shape of the Brussels sprout has been changed in that new species have been developed which have a more round shape compared to the older specie which were more oval. 
       SUMMARY 
       [0005]    Processes and devices for cutting off the tail end of Brussels sprouts are disclosed. 
         [0006]    In one example, starting from a stack of Brussels sprouts, one Brussels sprout at a time is separated from the stack and transferred to a longitudinal transport track, on the transport track the Brussels sprout is treated and manipulated such that it occupies a position in which the dimension of the Brussels sprout with the greatest length is positioned substantially perpendicular to the direction of the transport track. Near the end of the transport track, the position and orientation of each individual Brussels sprout is defined by means of photographic detection. Each individual Brussels sprout is removed from the transport track by means of a gripper. The position and orientation of the gripper are defined by means of the detected position and orientation of the Brussels sprout to be removed. The gripper with the Brussels sprout is re-oriented and moved along a knife whereby the tail end of the Brussels sprout is cut off, and the Brussels sprout treated like this is removed from the gripper and collected in a receiving tray. 
         [0007]    By handling each Brussels sprout in an individual way and using a cutting system which is adapted to an actual shape of each individual Brussels sprout the cutting process is optimized. More specifically the loss in weight can be reduced to about 10% compared with the 30-40% as was normal with the prior art processes. Moreover, a consumer receives a ready to cook product superior in quality to that produced by the prior art approach. One aspect is that the leaves are still closed around the Brussels sprout during cooking, with the result that the Brussels sprout is still intact after cooking, and fewer loose leafs exist in the cooking vessel. 
         [0008]    A further aspect relates to a device for performing the process of removing the tail end of Brussels sprouts. Still further aspects relate to cutting Brussels sprouts in half, either after trimming of the tail end, or alone. Cutting in half is an example of a generalized category of cutting or sectioning sprouts achieved by gripping a sprout and moving the sprout relative to a cutting tool. A variety of implementations of these disclosures can be realized. For example, a water knife can be provided as a cutting tool. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Other characteristics and advantages of disclosed aspects will become clear from the following description, which references the annexed drawings, in which 
           [0010]      FIG. 1  depicts a perspective view of a portion of a device that can be used in performing processes according to the description; 
           [0011]      FIG. 2  depicts an example process of trimming a Brussels sprout; 
           [0012]      FIG. 3  depicts an example process of estimating a position and orientation of a Brussels sprout using a captured image of the Brussels sprout; 
           [0013]      FIG. 4  depicts a top view of an example device that can be used to automatically trim Brussels sprouts; 
           [0014]      FIG. 5  depicts a side view of the device of  FIG. 4 ; 
           [0015]      FIG. 6  depicts a larger view of a camera portion of the device of  FIG. 4 ; 
           [0016]      FIG. 7  depicts a larger view of a gripping and trimming portion of the device of  FIG. 4  and can also serve as a side view of a device according to the device depicted in  FIG. 1 ; and 
           [0017]      FIGS. 8   a  and  8   b  depict examples of rollers that can be used in the device of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    The example device for removing the tail end of a Brussels sprout comprises a separation unit, a transport and orientation unit, a detection unit, and a cutting unit. Each Brussels sprout to be handled will pass through these four units before it will be laid down in clean condition in a receiving tray. 
         [0019]    It is accepted that Brussels sprouts are supplied as all goods in containers or the like and that, in the separation unit, one Brussels sprout at a time is separated from the stack of products and transferred to the transport and orientation unit. 
         [0020]    For that purpose a unit can be used as described in WO-A-2006-094837 which is incorporated by reference into this specification. Although the device described there is intended to be used with onions, the same type of device can be used with minor changes with respect to the dimensions so as to make it usable with Brussels sprouts. The Brussels sprout can first be brought into a storage bin as described in this earlier patent application and transported one by one upwardly. At the end of this upward movement, each individual Brussels sprout will fall into a vertical chute which, having its upper end at the end of the upward movement path of the separation unit and its lower end just above one end of the transport and orientation unit. This lower end is provided with a valve so that a Brussels sprout arriving there can be withheld for some time until a transport set of the transport unit is in the right position as will be described later. At that time the valve can be opened and the Brussels sprout transferred to the transport and orientation unit. 
         [0021]    The transport and orientation unit can be of the type as described in Dutch patent specification 1025386. The transport device described in this specification is of the type to be used with onions, but with the same type of device and an adaptation of the dimensions it can also be used for transporting and orienting Brussels sprouts. Part of the transport and orientation unit  10  is shown in the  FIG. 1 . 
         [0022]    The transport and orientation unit comprises a number of endless chains  11 , each of which is running over a number of wheels, one of which can be driven thereby moving the chains  11 . The upper part of each chain is substantially horizontal and forms the so-called transport track; this is the part in which the Brussels sprouts are transported from the separation unit to the cutting unit thereby passing the detection unit. 
         [0023]    Between each pair of adjacent chains there is provided a number of pairs of parallel axis  12 , each of these axis carry two rollers  13  each having the general form of a truncated cone and the ends with the smaller diameter being directed towards each other. Four rollers on a pair of parallel axis form together a support for a Brussels sprout to be transported as described above. As shown in the drawing between each pair of chains there is a number of pairs of axis and each axis carries more than one pair of rollers, but the invention can be performed with only one pair of rollers on each axis. 
         [0024]    Each roller is free rotatable around the axis on which it is mounted. Otherwise each roller is connected to a chain wheel which is free rotatable mounted on the same axis and which in the upper transport track part extends below the chains  11 . Under the transport track part of the chains there is mounted a number of endless chains cooperating with these chain wheels, which chains (not shown) can be driven so that during the movement of the chains  11 , the rollers are rotatably driven. The movements of these additional chains can be selected in such a way that either the rollers in each set of two pairs are driven in one direction, whereas the other pair of rollers on the adjacent axis are driven either in the same circumferential or in opposite circumferential direction. Moreover, the circumferential velocity can be freely selected. 
         [0025]    The additional chains responsible for the rotating movement of the rollers are only active in the part of the transport track before reaching the detection unit. Once a set of rollers entering the detection zone the engagement between the additional chains and the chain wheels stops and the rollers are no longer rotating. In this way, the Brussels sprout is in a stable position for being photographed or otherwise optically analyzed. 
         [0026]    As explained in the already mentioned Dutch patent specification 1025386, the movement of the rollers does agitate the Brussels sprout in such a way that it has the tendency to direct its longitudinal axis in a direction which is substantially perpendicular to the direction of the transport track, or the general direction of the chains  11 . In this way all the Brussels sprout arriving in the detection unit will have the same orientation in so far that the orientation of the tail end is not fixed but can be twofold. 
         [0027]    The detection unit (not shown) is provided in the end part of the transport track above the same and includes a digital camera, where one camera can be provided for each set of four rollers provided on an axis as seen along the longitudinal direction of said axis. As soon as the set of four rollers in a stationary condition and carrying a Brussels sprout arrives at a defined position the camera will make a picture of the Brussels sprout and transfer it to a computer. 
         [0028]    In the computer the picture of the Brussels sprout is analyzed in that its circumference is defined and based upon that the largest dimension of the Brussels sprout is defined which will be defined as the longitudinal direction of the Brussels sprout. At the same time the largest dimension of the Brussels sprout in the direction perpendicular to its longitudinal direction is defined and the tail end is defined based upon the general shape of the two ends of the Brussels sprout at the end of the longitudinal axis. The tail end is generally the not rounded end part of the sprout, which has commonly a more or less straight shape. As the Brussels sprout is generally not exactly oriented in a direction perpendicular to the direction of the transport track, the angle position of the Brussels sprout with respect to that direction is also defined. With these data it becomes possible to control a gripping device that will take the Brussels sprout from the set of four rollers and transport it through the cutting unit, before releasing it in a receiving tray. 
         [0029]    In the cutting unit there are provided a number of gripping devices, one for each of the parallel transport tracks present in the transport unit, which are adapted to take the Brussels sprouts form the support rollers in the transport tracks. 
         [0030]    Each gripping device as such comprises a gripper  16 , which is mounted on a substantially vertical axis  15  which is rotatably mounted on a bracket  14 . The brackets  14  are mounted on a frame bar  21  which can be moved back and for along a sliding surface  17 , which is under an angle with respect to the transport tracks so that by a movement of the frame bar  21  along the sliding surfaces  17 , the grippers  16  are moving back and forth with respect to the transport track. 
         [0031]    Each of the grippers  16  comprises two claw-like members which are positioned opposite each other as commonly known in the art, and which can be moved towards each other in order to grip a Brussels sprout, and which can be opened so as to release a Brussels sprout. As the axis  15  is rotatably mounted in the bracket the angle orientation of the gripper can be adjusted to the actual angle position of the Brussels sprout of the Brussels sprout on the support rollers in the transport track. 
         [0032]    Moreover, the bracket  14  is moveable with respect to the frame bar in a direction parallel to the length of the frame bar  21 . This allows the gripper to be adjusted accurately with respect to the Brussels sprout so that the gripper acts on that part of the Brussels sprout with the largest diameter by movement of the gripper to the right position as detected in the detection unit. 
         [0033]    The actuation of the different movements to be performed in the gripping unit will not be described in detail as this is obvious for the man skilled in the art. The different movements can be obtained by hydraulic, pneumatic and/or electro-magnetic devices or combinations thereof. 
         [0034]    Between the two sliding surfaces  17  there is mounted a bar  18  on which there are mounted a number of knife blades  20  which are oriented with their cutting edge in the direction of the sliding surfaces  17 . The position of these knife blades is such that a Brussels sprout gripped by the gripper  16  and oriented in the right way will be removed from its tail end during the movement of the frame bar upwardly along the sliding surfaces  17 . 
         [0035]    The operation of the device is described with respect to  FIG. 2 , as follows. At  55 , a Brussels sprout is provided on the transport track. At  56 , after a Brussels sprout had been transferred to a set of support rollers  13  in the transport track it will be agitated in such a way by the rolling movement of these rollers that it occupies a position in which its longitudinal axis is substantially oriented in a direction perpendicular to the direction of the transport track. There might be a possible deviation of some degrees, but the main direction is like that. At  57 , the configuration, position and orientation of the Brussels sprout is detected and at  58 , the gripper is positioned in such a way that it will pick up ( 59 ) the sprout from its set of support rollers in the optimal way, in which is the gripper is oriented ( 60 ) in line with the possible orientation of the Brussels sprout and taking into account its actual shape. The gripper picks up ( 59 ) the Brussels sprout and is taking a orientation ( 60 ) such that the longitudinal axis of the sprout is perpendicular to the longitudinal direction of the transport track and its lateral position is corrected such that the tail end of the sprout will be trimmed off from the Brussels sprout during the movement along the sliding surfaces. If needed and based upon detection by the detection unit the orientation of the Brussels sprout is reversed over 180° by rotation of the gripper over 180° ( 61 ,  62 ), in order to have the tail end of the Brussels sprout at the side of the cutting blade  20 . By positioning and orienting the Brussels sprout in this way by movement of the gripper the tail end can be removed ( 63 ) with a very high degree of accuracy, so that the Brussels sprout is almost not damaged. The trimmed Brussels sprout is released ( 64 ) into a receptacle. 
         [0036]      FIG. 3  depicts an example process for detecting position and orientation of Brussels sprouts ( 57 ), using an image taken of each Brussels sprout. In an example, each image is taken using a single and contrasting background color, and for example, a black background. The example process comprises a plurality of parallel and different recognition parts, which are used composed into a determined position and orientation. Color pre-processing ( 103 ) uses multiple images of sprouts to identify the 2D color plane information, which can be used as input to the following parts of the process In one approach, this process includes edge detection to separate the sprout from background ( 105 ) based on the 2D colour plane identified in  103 , resulting in an identification of pixels that form a boundary between the sprout and the background. An ellipse is fitted ( 107 ) to the detected pixels. A least mean squares fitting algorithm can be used. 
         [0037]    Using the ellipse, the ends of the sprout are differentiated ( 109 ) from its midsection. For the ends, color differentiation within the sprout is used to identify ( 111 ) an end to be trimmed, distinguishing the opposite end. In an example, the trim end contains a higher proportion of white, such that the proportion of white to green is a distinguishing characteristic. An orientation of the sprout is estimated ( 113 ). 
         [0038]    In  FIG. 3 , the example process includes a parallel track in which the sprout is separated ( 115 ) from background using the 2D colour plane data from  103 , and a circle is fitted ( 117 ) with a radius that tracks a smooth contour found on the sprout (on the end opposite the trim section). This circle fitting would generally under estimate the extent of the sprout on the side to be trimmed. As such, pixels outside of the circle are identified ( 119 ), and regions of such pixels are grouped ( 121 ). Among those regions, a color differentiation ( 123 ) can be used to identify an end of the sprout to be trimmed (as in  111 , described above). From this information, an orientation of the sprout can be estimated ( 125 ). Another example approach includes separating ( 115 ) the sprout from background, determining ( 130 ) an angular orientation of the long center axis of the sprout (rotational axis through ends), calculating ( 132 ) a center of the sprout, and calculating ( 134 ) a distance from the center to the edge along the determined angular orientation. 
         [0039]    The information obtained from each estimation can be averaged or otherwise composited ( 127 ) to arrive at a decision concerning the position of the sprout and orientation of the end to be trimmed. These estimations can use different algorithms. This disclosure should not be interpreted to require use of multiple algorithms, and those of ordinary skill would understand that if a single algorithm were found to produce satisfactory results, then a single algorithm can be used. The determined orientation and position can be outputted ( 129 ). 
         [0040]      FIG. 4  depicts a top view of an example device that can automatically trim Brussels sprouts.  FIG. 4  depicts some of the elements introduced in  FIG. 1 . In particular,  FIG. 4  depicts grippers  16 , and rollers  13 . A motor  22  is depicted. In the example of  FIG. 4 , a set of spinning blades  29  serve to trim the Brussels sprout (while  FIG. 1  depicts a set of fixed blades  20 ). Spinning blades may provide a better cut, reducing damage to the trimmed Brussels sprout. A number of sets of rollers are also depicted, with one set identified as  32 . 
         [0041]      FIG. 5  depicts a side view of the example device introduced in  FIG. 4 .  FIG. 5  depicts spinner blades  29 .  FIG. 5  also depicts the grippers  16  in two positions, as they are operable to move on the track  17  apparatus shown in  FIG. 1  (which is not shown here in outline, to avoid obstructing grippers  16 . A camera  25  is shown relatively disposed to the apparatus portion of  FIG. 1 , and to the rollers depicted in  FIG. 4 . The drive chain  11  depicted in  FIG. 1  also is identified here. A Brussels sprout  33  is identified, to aid in understanding a path through the machine. A receptacle  40  that collects trimmed sprouts through opening  41  is shown. Such receptacle can be removable and replaced while the machine is in operation. 
         [0042]      FIG. 6  depicts a larger view of the camera  25 , and shows sprout  33 , moved from a location in  FIG. 4 . A grip position, at which grippers  16  can grip the sprouts is shown, relative to the side view of the rollers. 
         [0043]      FIG. 7  shows a detailed view of the area of the device of  FIG. 4  proximal grip position  31 . Spinner blades  29  are shown, along with gripper  16 . A high position  30  is generally identified, and in conjunction with grip position  31  depicts an example movement pattern of grippers  16 . Spinning blades  29  are an example of a cutting implement. A variety of other cutting implements can be provided. In one example, a water knife can be provided and disposed so that a cutting stream of water is provided in a location at which gripper  16  can move sprouts to be trimmed across the stream of water, thereby trimming or otherwise cutting the sprout as intended. A cuisinart style blade can be provided, and in such an implementation, gripper  16  would move a tip of the sprout into the blade in a direction traverse to a plane in which the blade spins (as opposed to generally parallel to a plane of spinning blades  29 , in the above disclosure). A fixed or moving wire can be used. These all are examples of cutting implements. In some examples, multiple cutting implements can be provided; for example, a tail end can be trimmed by one cutter, and the sprout cut in half by another. 
         [0044]    The above disclosures related primarily to an example of trimming a tail end of a Brussels sprout. However, implementations of the disclosure are not limited to trimming a tail end of a Brussels sprout, or to only trimming a tail end of the Brussels sprout. In one example, a Brussels sprout can be cut in half; for example, along a long dimension of the sprout. In the above examples, a Brussels sprout is gripped traverse to the long dimension, so a midline along the long dimension of the sprout is exposed and the sprout does not need to be re-gripped or the sprout re-oriented with respect to gripper  16 . Rather, the sprout can simply be repositioned while being held by gripper  16 . In one example, gripper  16  can grip a sprout as disclosed above and position the sprout relative to one blade of spinning blades  29  to trim the tail end, as described above. After such tail end trimming operation, the gripper can be controlled to move the sprout, in a relative orientation with respect to one blade of spinning blades  29 , to cut the sprout in half. As can be understood from these examples, a variety of trimming operations can be performed using the disclosed gripper  16  by positioning (repositioning) the sprout relative to a blade from blades  29  and moving gripper relative to the blade to complete each of the trimming operations. Where grippers  16  operate to move a sprout along the length by moving generally in one directional motion, grippers  16  can reorient, and reverse motion in order to cut the sprout in half, and then release the sprout, for example. 
         [0045]    Grippers  16  are programmatically controlled, and thus trimming operations can be selected and sequenced as required. For example, one batch of sprouts may be both trimmed and cut in half, while another batch may be trimmed only, and a further batch only cut in half. Cutting in half and trimming the tail end are examples of trimming operations that can be performed according to the disclosure. Grippers used in implementations can have different capabilities, such as movement speed, accuracy, and degrees of freedom. Other components of the overall system can be selected or adjusted in view of a type of gripper to be used, and vice versa. These considerations are within the scope of decisions to be made by those of ordinary skill, in view of these disclosures. 
         [0046]    In the above disclosure, it was described that gripper  16  does not need to release a sprout between the example cutting operations of trimming and cutting in half. However, this is not to the exclusion of releasing and regripping the sprout, if desired. 
         [0047]      FIG. 8   a  depicts a magnified view of rollers  32  depicted in the top view of  FIG. 4 .  FIG. 8   b  depicts a top view of another embodiment of such rollers, identified as rollers  35 . Rollers  35  have a solid portion  36  in locations where rollers  32  have gaps. Rollers  32  and  35  each have a narrow waist providing diabolo-shaped portions  37 . 
         [0048]    The above disclosure provided examples where rollers  32  pre-orient sprouts so that they are in a relatively similar position at a point when they are imaged and gripped by grippers  16 . It is expected that this approach may aid in efficiency. However, other examples include situations where a gripper can grip a sprout that may be in an arbitrary orientation. So, rollers  32  may be excluded or may be substituted by another delivery mechanism that does not tend to orient sprouts into a generally common orientation. Whether or not to use rollers  32  may be determined according to an amount of (extra) time, if any, required to determine an orientation of a sprout to be gripped, as well as degrees of freedom or movement provided by a gripper to be used. Also, throughput considerations relating to how quickly an arbitrary orientation can be gripped or the amount of slippage may be other considerations that would occur to those of ordinary skill in view of the disclosure. 
         [0049]    It also should be apparent from the above disclosures that implementations of the examples are scalable, in that more instances of rollers, cameras, grippers and cutters can be provided in a parallel format to increase throughput. These examples included examples where there was a 1:1 correspondence between rollers, cameras and grippers. However, some implementations may provide that one set of rollers feeds multiple camera and gripper paths, or that multiple sets of rollers feed one camera and gripper path, for example. 
         [0050]    The invention is not restricted to the described embodiments as shown in the annexed drawings, but that within the scope of the claims modifications, can be applied without departing from the inventive concept.