Robotic shrimp deheading

Abstract

Apparatus and methods for deheading shrimp robotically. Images of shrimp supported on one side on a moving or stationary support surface are produced by a visioning system. A controller uses the images to position and orient a robot's end effector with respect to a shrimp to be deheaded. Once in position one version of the robot thrusts the end effector downward to impact the shrimp and separate the shrimp's head from its abdomen. A bumper on the end effector is made of a resilient material to flatten upon impact with the shrimp on the support surface and produce oppositely directed forces that tend to push the abdomen away from the head. Other versions of the robot use more rigid bumpers with specially contoured contact faces designed to sever shrimp heads from abdomens. Pushers are coordinated with the bumpers to push the shrimp abdomens away from their severed heads.

Description

[0001] ROBOTIC SHRIMP DEHEADING

[0002] BACKGROUND

[0003] The invention relates generally to apparatus and methods for deheading shrimp and more particularly to the robotic deheading of shrimp.

[0004] In the shrimp processing industry, shrimp farms often remove the heads from shrimp before icing and shipping the deheaded shrimp to customers, such as processors that have automated peeling equipment to remove the shells. By first deheading the inedible carapace and its contents, the shrimp farm can save itself or its customers on shipping costs. And because the organs housed in the head's carapace are removed, concerns about the organs' deterioration and the potential of their sliminess to reduce the effectiveness of automated shrimp peeling machines are alleviated. But removing the heads is labor intensive because it's done by hand. With the large volume of shrimp that shrimp farms harvest, it takes many workers to dehead all the shrimp. Another problem is the segregation of removed heads from shrimp meat and the disposal of the heads.

[0005] SUMMARY

[0006] An automated shrimp deheading system embodying features of the invention comprises a support surface configured to support shrimp having a head helmeted by a carapace and an abdomen joined to the head at a junction that extends between first and second lateral sides from a dorsal side to a ventral side at which legs extend from the head. The first lateral side lies on the support surface, and the second lateral side faces upward. A visioning system produces images of the shrimp on the support surface to pinpoint their positions and orientations. A controller executes software program steps to process the images and produce control signals corresponding to the positions and orientations of the shrimp. A robotic deheader includes a vertical arm that has an end effector at a lower end. The end effector includes a bumper. A positioning and orienting mechanism is coupled to the vertical arm and is configured to selectively position the vertical arm parallel to the support surface in response to control signals from the controller and to orient the end effector about an axis transverse to the support surface in response to control signals from the controller. A bumper actuator is coupled to the end effector and is configured to selectively thrust the bumper downward toward the support surface in response to control signals from the controller. The positioning and orienting mechanism positions the end effector so that the bumper is positioned above the shrimp and oriented so as to impact the shrimp from the second lateral side along the carapace when the bumper is thrust downward by the bumper actuator to break the junction of the head and the abdomen.

[0007] A method for deheading shrimp comprises: (a) conveying shrimp having a head helmeted by a carapace and an abdomen joined to the head at a junction that extends between first and second lateral sides from a dorsal side to a ventral side at which legs extend from the head, wherein the first lateral side lies on a conveyor belt and the second lateral side faces upward; (b) producing images of the shrimp as they pass by on the conveyor belt; (c) determining the orientation and position of each of the shrimp on the conveying surface from the images; (d) tracking the position of the shrimp as they are conveyed by the conveyor belt at a belt speed; (e) moving a robotic deheader including an end effector having a line of initial contact in position above a shrimp to be deheaded;

[0008] (f) orienting the end effector to align the end effector's line of initial contact with a deheading line on the first lateral side of the carapace parallel to a line extending from a notch at the dorsal side of the junction to the shrimp's legs closer to the abdomen; and

[0009] (g) thrusting the end effector down against the carapace from the second side to impact the shrimp and break the junction between the head and the abdomen.

[0010] A robotic shrimp deheader for deheading a shrimp having a head joined to an abdomen at a junction comprises a vertical arm, a translator, a rotator, and a bumper actuator. The vertical arm has an end effector at a lower end of the vertical arm. The end effector includes a bumper. The translator is coupled to the vertical arm and is configured to selectively translate the vertical arm in a plane. The rotator is coupled to the vertical arm and is configured to selectively rotate the vertical arm about an axis transverse to the plane. The bumper actuator is coupled to the end effector and is configured to selectively thrust the bumper downward. The translator and the rotator position the end effector so that the bumper is positioned above a shrimp and oriented so as to impact the shrimp when the bumper is thrust downward by the bumper actuator against the shrimp to break the junction of the head and the abdomen.

[0011] Another automated shrimp deheading system comprises narrow conveyors spaced apart across gaps and conveying shrimp in a conveying direction to a downstream end of the narrow conveyors and one or more takeaway conveyors below the narrow conveyors upstream of the downstream end configured to advance transverse to the conveying direction. A robotic deheader separates the heads from the abdomens of the shrimp on the plurality of narrow conveyors and pushes the heads or the abdomens off sides of the narrow conveyors and onto the one or more takeaway conveyors below. An outfeed conveyor at the downstream end of the narrow conveyors receives shrimp heads or abdomens not pushed off onto the takeaway conveyors.

[0012] BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is the anatomy of a shrimp.

[0014] FIG. 2 is a top plan schematic of an automated shrimp deheading system.

[0015] FIG. 3 is a side elevation schematic of the shrimp deheading system of FIG. 2. FIGS. 4A and 4B are axonometric views of one version of a vertical robotic arm usable in a deheader as in FIG. 2.

[0016] FIG. 5 is an exploded view of the end effector of the robotic arm of FIGS. 4A and 4B. FIG. 6 is a lateral side view of a shrimp showing the deheading line.

[0017] FIG. 7 is a side elevation view of the robotic arm of FIGS. 4A and 4B advancing through a shrimp.

[0018] FIG. 8 is an isometric view of a second version of a vertical robotic arm usable in a deheading system as in FIG. 2.

[0019] FIG. 9 is an enlarged drawing of one of the end effectors of the robotic arm of FIG. 8 deheading a shrimp.

[0020] FIG. 10 is a side elevation view of left-side end effectors of the robotic arm of FIG. 8 pushing a shrimp body away from a severed head.

[0021] FIGS. 11 A and 11B are isometric views from different perspectives of a bumper usable in the robotic arm of FIG. 8. FIG. 11C is a bottom plan view of the bumper of FIGS. 11A and 11B.

[0022] FIG. 12 is a bottom view of the bumper of FIGS. 11A-11C deheading a shrimp.

[0023] FIG. 13 is an isometric view of a third version of a vertical robotic arm usable in a deheading system as in FIG. 2.

[0024] FIG. 14 is an enlarged isometric view of end effectors of the robotic arm of FIG. 13 shortly before deheading a shrimp. FIGS. 15A and 15B are bottom plan and isometric views of the robotic arm of FIG. 13 pushing a shrimp body away from a severed head.

[0025] FIG. 16 is an isometric view of a fourth version of a vertical robotic arm usable in a deheading system as in FIG. 2.

[0026] FIG. 17 is a bottom view of the robotic arm of FIG. 16.

[0027] FIG. 18 is a top plan schematic of another version of an automated shrimp deheading system.

[0028] DETAILED DESCRIPTION

[0029] The terms used in this description and in the claims in reference to the body of a shrimp are defined in reference to FIG. 1. A shrimp 20 has a head 22 and an abdomen 24 joined to the head at a junction that extends between first and second lateral sides 26 from a dorsal side 28 to a ventral side 29. The abdomen 24 contains the shrimp's edible meat. The head 22 is helmeted by a carapace 30. Walking legs (legs) 32, extend from the ventral side 29 of the head 22. The inedible legs 32, often referred to as gristle, attach to the head 22 from near the junction forward along most of the ventral side 29 of the head. A notch 34 in the dorsal side 28 defines one end of the junction of the head 22 and the abdomen 24. The end 35 of the junction on the ventral side is near the rear end of the attachments of the legs 32 to the head 22.

[0030] One version of an automated shrimp deheading system is shown in FIGS. 2 and 3. Shrimp 20 are conveyed lateral side down atop a support surface 36 provided by the outer face of a conveyor belt 38 advancing in a conveying direction 40. A visioning system 42 including a camera mounted above the conveyor belt 38 produces images of the shrimp 20 on the support surface 36 as they pass by. The images are digitized into digital images 44 that are sent to a controller 46. The controller 46 comprises one or more programmable processors that execute software program steps to process the images 44 and produce control signals 48 corresponding to the lateral (Y) and longitudinal (X) position and the orientation of each shrimp 20 on the support surface 36. With knowledge of the speed of the conveyor belt 38 from an angle encoder, for example, and the longitudinal position of the shrimp 20 in the conveying direction 40 when imaged, the controller 46 tracks the shrimp's advancing longitudinal (X) position. The shrimp's lateral (Y) position doesn't change in normal operation. A robotic deheader, or deheading robot 50, downstream of the visioning system 42 receives the control signals 48 from the controller 46. The robot 50 has a vertical arm 52 that terminates in an end effector 54. The robot 50 has a translator to translate the vertical arm 52 in the X and Y directions, as indicated by the four arrows extending from the deheader 50 in FIG. 2, and, consequently, the end effector 54 in a plane parallel to the support surface 36. The robot's translator can be realized in different ways. For example, the robot 50 can be a gantry robot, such as one with one set of rails that spans the width of the conveyor belt 38 in the Y direction and a second set of rails that can translate in the X direction along the first set or rails. The vertical arm is affixed to the second set of rails so that it can be translated in both the X and Y directions. A Y actuator translates the second set of rails and, consequently, the vertical arm in the Y direction. An X actuator translator translates the vertical arm along the second set of rails in the X direction. The actuators and the rail system compose the translator. As another example, the robot 50 can be an articulated robot, such as one with two joints: a first joint at a proximal end of a first horizontal arm and a second joint at the distal end of the first horizontal arm. The first joint, which is fixed in position above a side of the conveyor belt, for example, is rotatable about a first vertical axis to swing its distal end along an arc over the conveyor belt and provide X and Y positioning of the second joint along the arc. A first actuator rotates the horizontal arm about the first joint's vertical axis. The first actuator, the rotatable first joint, and the horizontal arm compose the translator in the articulated robot.

[0031] In a gantry system the robot 50 has a rotator to rotate the vertical arm 52 about the robot's Z axis 56 to properly orient the end effector 54 to the orientation of the shrimp. In an articulated robot in which the vertical arm and the second joint share the same vertical axis, the rotator would operate in the same way as for the gantry system. If the articulated robot has a second horizontal arm connected to the first horizontal arm by the second joint and the vertical arm is distal to the second joint on the second horizontal arm, the combined rotation of the first and second joints defines the orientation of the end effector. In that case, both horizontal arms and both joints also serve as rotators.

[0032] Together, the translator and rotator form a positioning and orienting mechanism. However the translators and rotators are realized in the deheading robot, their combined operation positions and orients the end effector correctly to dehead each shrimp along an optimal contact line on the side of the shrimp.

[0033] The end effector 54 can be lowered and raised in the Z direction transverse to the support surface 36 by a Z actuator as indicated by the two-headed arrow in FIG. 3. The positioning and orienting mechanism of the deheading robot 50 positions the end effector 54 so that it is positioned above the shrimp 20 to be deheaded and oriented to impact the shrimp on the carapace and break the junction between the head and the abdomen. The result is separated shrimp heads 22 and abdomens 24 downstream of the deheader 50.

[0034] Details of one version of a vertical arm usable in the deheading system of FIG. 2 are shown in FIGS. 4A, 4B, and 5. The vertical arm 60 has a bumper actuator 62, such as a pneumatic cylinder. The bumper actuator 62 has a push rod 64 attached at its outer end to an end-effector frame 66. Releasably attached to the end-effector frame are a bumper 68 and two pillows 70 flanking the bumper. A collar 72 around the lower end of the actuator 62 has a tongue 74 with a hole receiving a stabilizing rod 76 whose lower end is attached to the end-effector frame 66. The rod 76 prevents the frame 66 from twisting when the bumper 68 encounters resistance.

[0035] The bumper 68 terminates at an upper end in a dovetail 78 that mates with a blind- ended dovetail socket 79 in the end-effector support frame 66. A cotter pin 80 through a hole 81 in the frame 66 retains the bumper 68 in place in the end effector, as best shown in FIG. 4A. The cotter pin 80 can be easily removed so that the bumper 68 can be slid out of the socket 79 and replaced.

[0036] The pillows 70 are also releasably attached to the end-effector frame 66. The upper end of each pillow 70 has a slot 82 that receives a plate 83. A pin 84 is attached at a lower end to the plate 83 and at an upper end to a cross pin 85. A cam lever 86 raises and lowers the plate 83. When the plate 83 is in the raised position as shown, the upper end of the pillow 70 above the slat 72 is squeezed tightly in place between the top of the plate 83 and the endeffector frame 66. Flipping the lever 86 180° lowers the plate 83 for easy removal and replacement. Thus, cooperating attachment structure on the end-effector frame 66 releasably retains the bumper 68 and the pillows 70.

[0037] As shown in FIGS. 4A and 4B, the pillows 70 are used to resiliently restrain the abdomen 24 and the head 22 of the shrimp 20 during deheading. But a single pillow 70 that helps restrain only the abdomen is possible. The pillows 70 are tent-shaped at their lower ends to fit around the shrimp 20. They are made of a resilient material, such as a soft rubber, to help them conform to the shapes of the head 22 and abdomen 24. And the soft rubber prevents the pillows 70 from cutting into and damaging the shrimp meat in the abdomen 24. The tent-shaped lower portion of the pillow 70 is joined to the upper attachment end by a pair of flexible legs 88. The legs 88 can also flex to help the pillow 70 conform to the shrimp.

[0038] The lower end of the bumper 68 has a rounded bottom. In this version the rounded bottom is formed by a cylindrical portion 90 with a major central axis 92. The rounded bottom of the bumper 68 defines a line of contact 94 containing all the lowermost points along its length parallel to the central axis 92. Like the pillows 70, the bumper 68 is made of resilient material, such as urethane or rubber. In that way the bumper 68, like the pillows 70, returns to its normal relaxed shape after deheading a shrimp 20.

[0039] Because shrimp 20 are oriented in different ways, the robotic deheader's end effector is rotatable over at least 180° and as much as 360° about the Z axis as indicated in FIGS. 2 and 3. In that way the bumper 68 can be oriented to the most effective deheading orientation. Testing has shown that an effective deheading line 94, or contact line, on the carapace 30 is parallel to a line 95 that extends from the notch 34 on the dorsal side 26 of the head-abdomen junction to a point 96 on the shrimp's legs 32 at the ventral side 28, as shown in FIG. 6. The robotic deheader's translator translates the vertical arm so that the midpoint of the bumper's line of contact is vertically above the midpoint 98 of the deheading line 94. The rotator rotates the arm so that the line of contact coincides with the deheading line 94 during deheading.

[0040] As shown in FIG. 7, when the bumper 68 is aligned by the positioning and orienting mechanism as just described, the bumper is rapidly thrust down by the bumper actuator 62 through the shrimp 20 to break the junction. The resistance of the support surface 36 to the resilient bumper 68 causes the bumper to flatten. The flattening of the bumper 68 creates oppositely directed forces 100 that urge the head 22 and abdomen 24 away from each other. The bumper actuator 62 then retracts the bumper 68 rapidly for the robotic deheader to be moved to the next shrimp to be deheaded.

[0041] An alternative version of a vertical arm for use in a deheading system as in FIG. 2 is shown in FIG. 8. The vertical arm 110 has a top base 112 that supports four linear actuators 114L, 114R, 116L, 116R. Bumper actuators 114L, 114R have push rods 118 attached at their outer ends to end-effector frames 120. Releasably attached to each of the end-effector frames 120 are a bumper 122L, 122R and a pillow 124. The pillow 124 is mounted to a pillow-frame extension 125, a cantilevered portion of the end-effector frame 120. A stabilizing rod 126 has a lower end attached to the frame 120 of each end effector. The lower ends of the bumper actuators 114L, 114R are mounted on a yoke 128. The stabilizing rods 126 extend through holes in the yoke 128 and prevent the end-effector frames 120 from twisting when the bumpers 122L, 122R encounter resistance while deheading. The upper ends of the bumper actuators 114L, 114R are mounted to the flanges of downwardextending L-shaped legs 130 of the base 112. The lower ends of pusher actuators 116L, 116R are mounted on a second yoke 129. The upper ends of the pusher actuators 116L, 116R are mounted to the flanges of shorter downward-extending L-shaped legs 131 of the base 112. A push rod 132 is axially coupled to a flexible pusher rod 134 by a coupling 136 for each pusher actuator 116L, 116R. Sheaves 138 are mounted between a pair of flanges 140 that extend from the end-effector frame 120. The flexible pusher rod 134 is guided by the sheaves 138. The actuators 114L, 114R, 116L, 116R are shown in FIG. 8 as pneumatic actuators with couplings 140 for air lines (not shown). But other kinds of linear actuators, such as hydraulic or electromagnetic, could be used in some applications. The robot 50 controlled by the controller 46 of FIG. 3 translates and rotates the vertical arm 110 as necessary to position and orient the appropriate bumper 122L, 122R to cut through the shrimp S along the deheading line.

[0042] FIG. 9 shows the bumper 122R in the process of deheading a right-side-up shrimp S with a deheading ridge 142 at the bumper's bottom cutting through the shrimp S between the shrimp abdomen A and the head H. The bottom of the bumper 122R is contoured with the ridge 142. The resilient pillow 124 with its two depending arms 144 is pushed downward by its associated bumper actuator 114R. The pillow wraps its arms 144 around the shrimp abdomen A to hold it in position during deheading.

[0043] After the bumper 122R has been driven by the deheading actuator 114R rapidly through the right-side-up shrimp S, it and the pillow 124 are raised by the actuator as shown in FIG. 10. Just before the bumper actuator 114R starts to raise the bumper 122R, the flexible pusher rod 134 is extended through the bumper by the pusher actuator 116R. The pusher rod 134 applies an impulse of force against the shrimp abdomen A to space it from the severed head H. Then the flexible pusher rod 134 is retracted.

[0044] A right-side bumper 122R is used for right-side-up shrimp, and a left side bumper 122L is used for left-side-up shrimp. The left- and right-side bumpers 122L, 122R are mirror images of each other. And because the bottoms of the bumpers 122L, 122R, which contact the shrimp, are different, two bumper actuators 114L, 114R are used— one for left- side-up shrimp and the other for right-side-up shrimp.

[0045] Details of a left-side bumper 122L are shown in FIGS. 11A-11C. The bumper 122L has an upper attachment member 146 in the form of an elongated post with upper and lower ribs 148 along each side. The attachment member 146 slides into and out of position in a complementary opening 149 in the end-effector frame 120 as shown in FIG. 8. The lower portion of the bumper 122L is characterized by a tunnel 150 that extends from an elevated position on a rear side 152 of the bumper to a lower position on a front side 153. The tunnel 150 is open at its bottom at the front side 153 of the bumper 122L. The tunnel 150 receives the pusher rod 134 (FIG. 10), which is extended through the tunnel to push the shrimp abdomen from the severed head after deheading. The pillow 124 holds the abdomen during the push so that the severed body isn't pushed off the side of the belt by the pusher rod 134.

[0046] The deheading ridge 142 of the bumper 122L of FIG. 11C has a special shape matched to the anatomy of shrimp. The ridge 142 has four non-collinear segments that lie in a bottommost plane of the bumper 122L. Each segment has a special purpose as shown in FIGS. 11C and 12. A first segment 160 of the deheading ridge 142 is divided into two L- shaped portions 162, 163 by an L-shaped groove 164 that opens onto a first side 165 of the bumper 122L. The outer portion 162 steps on and holds the shrimp's walking legs, or gristle G, while the inner portion 163 severs the gristle from the shrimp S. The groove 164 improves the grip of the first segment 160 on the shrimp's gristle G. A short second segment 166 extends at a right angle from the longer leg of the inner L-shaped portion 163 of the first segment 160. The second segment 166 steps on the shrimp's throat meat nearest the gristle G. A third segment 168 extends obliquely from the second segment 166 to define a V with the first and second segments 160, 166. The V forms a notch 170 in which the throat meat resides during deheading to prevent it from being severed from the meat in the shrimp's abdomen A. A fourth segment 172 extends from the third segment 168 parallel to the shorter leg of the L-shaped first segment 160 and terminates at an opposite second side 173 of the bumper 122L. The fourth segment 172 steps on the junction of the abdomen A and the head H above the throat meat and pushes through the junction to separate the head from the abdomen.

[0047] The bumper 122L is made of a rubber material having a hardness of between 60 and 95 Shore A, but preferably from 85 to 95 Shore A. But higher or lower Shore A hardnesses will also work. Bumpers of different sizes are used for shrimp batches of different sizes. Bumpers of different hardnesses can be used for different varieties and qualities of shrimp. And different deheading-ridge designs can be used for different varieties of shrimp.

[0048] A third version of a vertical arm for use in a deheading system as in FIG. 2 is shown in FIG. 13. The vertical arm 180 is similar to the vertical arm 110 of FIG. 10. The main difference is that the pillows 124 in the vertical arm 180 of FIG. 13 are moved away from and back toward the bumpers 122L, 122R by the same actuators 116L, 116R that operate the pushers 134. In that way the pillows 124 pull shrimp abdomens away from the severed head while the pushers 134 push them. The push rods 132 of the pusher actuators 116L, 116R are connected to couplings 182. The flexible pusher rod 134 and two other flexible rods 184— pillow rods— extend from the coupling 182. Each pair of the other flexible rods 184 is guided around sheaves 186 and through passageways 188 through a deheading end-effector frame 190 to a pillow-frame extension 192 to which the pillow 124 is mounted. The pillowframe extension 192 is a cantilevered portion of the end-effector frame 190. Each flexible pillow rod 184 is guided through a pillow ring 196 on the pillow-frame extension 192. The distal ends of the flexible pillow rods 184 are attached to the pillow-frame extension 192. In that way the pusher actuators 116L, 116R push the pillows 124 away from the bumpers 122L, 122R and pull the pillows back toward the bumpers.

[0049] In FIG. 14, the bumper 122R, the pillow 124, and the pusher rod 134 are shown in idle positions just before deheading a right-side-up shrimp S. The robot 50 controlled by the controller 46 of FIG. 3 translates and rotates the vertical arm 180 as necessary to position and orient the right-side bumper 122R to cut through the shrimp S along the deheading line. Meanwhile, the left-side bumper 122L is in its raised idle position, and the pusher rod 134 and the pillow 124 are in their raised idle positions. FIGS. 15A and 15B show the controller's coordinated operation of the pusher rod 134 and the pillow 124 in pushing a left-side-up shrimp abdomen A away from a severed head H. In FIGS. 15A and 15B the pusher rod 134 and the two pillow rods 184 are in an extended state. The pusher rod 134 pushes the abdomen A away from the severed head H while the pillow 124 holds the abdomen to prevent it from being ejected off the conveyor belt by the force impulse applied by the pusher rod.

[0050] An example deheading sequence starting from the idle positions is as follows:

[0051] (1) the bumper actuator 114L starts to extend its push rod 118 to rapidly lower the bumper 122L, the pillow 124, and the pusher rod 134 toward the left-side-up shrimp S;

[0052] (2) at the same time or shortly thereafter while the flexible pusher rod 134 and the pillow 124 are being lowered, the pusher actuator 116L starts to rapidly retract its push rod 132 to withdraw the flexible pusher rod and slide the pillow toward the bumper 122L into position to hold the shrimp S;

[0053] (3) after the bumper 122L has cut through the shrimp, the pusher actuator 116L starts to extend its push rod 132 and the flexible pusher rod 134 through the bumper to push the shrimp abdomen A away from the severed head H while the pillow 124, still in position holding the shrimp, moves with the pusher rod to hold the abdomen during the pusher's push that separates the abdomen from the severed head;

[0054] (4) after the separation is complete, the bumper actuator 114L starts to retract its push rod 118 to rapidly raise the bumper 122L, the pillow 124, and the pusher rod 134 toward their idle positions;

[0055] (5) optionally, while being raised by the bumper actuator 114L, the pillow 124 can be moved slightly and rapidly toward the head H and back again along the pillowframe extension 192 by the pusher actuator 116L to help release the shrimp abdomen A.

[0056] The deheading sequence for each shrimp takes less than about 100 ms from start to finish.

[0057] The bumpers 122L, 122R of the vertical arms 110, 180 of FIGS. 8 and 13 are removable from the end-effector frames 120, 190 in the same way as the bumper 68 in the robotic arm 60 of FIG. 5. And the pillows 124 of the vertical arms 110 of FIG. 8 are removable in the same way as the pillows 70 in the vertical arm 60 of FIG. 5.

[0058] A fourth version of a vertical arm for use in a shrimp-deheading system as in FIG. 2 is shown in FIG. 16. The operation of the vertical arm 200 is the same as for the vertical arm 180 of FIG. 13. But there are some structural differences.

[0059] First, flexible pusher rods 202 have an inverted U-shaped cross section rather than the circular cross section of the pusher rods 134 of FIG. 13. The inverted U-shaped cross section has a flat bottom 203 that scrapes a larger area of the support surface than does a circular pusher rod. The flat bottom 203 helps loosen the bond between the shrimp's abdomen and head.

[0060] Second, right and left pillow-pusher actuators 204R, 204L are all angled away from bumper actuators 206R, 206L at a shallower angle than the pusher actuators 116R, 116L of FIG. 13. The shallower angle causes less stress on the flexible pusher rods 202.

[0061] Third, instead of using a single stabilizing rod 126 with each push rod 118 as in FIG. 8, this version uses flanks each push rod 210 with a pair of stabilizing rods 208. The additional stabilizing rods 208 passing through four bearing tubes 212 in a bearing structure 214 increase the stability of the bearing structure and consequently the life of the bumper actuators 206R, 206L.

[0062] Fourth, the left and right pillows 216L, 216R are mirror images of each other. The left pillow 216L has an inside edge 218L that follows the natural curve of left-side-up shrimp. And each right pillow 216R has an inside edge 218R that follows the curve of right-side-up shrimp. Outer ends 220L, 220R of the pillows 216L, 216R slope downward to help confine the shrimp. The sloped outer ends 220L, 220R cooperate with downward-sloping outer flaps 222 to cushion a shrimp whose tail section extends through an intervening gap 224.

[0063] Another version of an automated deheading system 300 is shown in FIG. 18. Shrimp 302 in bulk in a feed 304 are singulated into lanes by a singulator 306. The shrimp 302 in each lane are advanced on a plurality of individual narrow conveyors 308, such as belt conveyors, spaced laterally apart across gaps 310. A visioning system such as the visioning system 42 of FIGS. 2 and 3, produces images of the shrimp 302 passing by. As shown in FIG. 3, the digitized images 44 are sent to the controller 46, which produces the control signals 48 for deheading robots 312. The robots 312 in FIG. 18 are shown as articulated robots but could be gantry robots. Immediately after deheading shrimps 302, the deheading robots 312 push the detached shrimp heads off the sides of the narrow conveyors 308 where they fall through the gaps 310 into a disposal area 314 below for collection and disposal. One or more takeaway conveyors 316 advancing through the disposal area 314 transverse to the narrow conveyors 308 collect the detached heads dropped onto them by the deheading robots 312 and convey them to be collected for disposal or other non-food use. Deheaded abdomens are conveyed off the downstream ends of the narrow conveyors 308 and collected for grading or other processing. An outfeed conveyor 318 can be used at the downstream end of the narrow conveyors 308 to convey the abdomens to a grader or other processing.

[0064] It's possible to configure the deheading system to instead push the abdomens off the narrow conveyors 308 onto the takeaway conveyors 316 for further processing and to drop the detached heads off the downstream ends of the narrow conveyors and onto the outfeed conveyor 318 for disposal. The end effector 320 can be similar to those shown in FIGS. 8-17 except that a pillow that could prevent a detached head or shrimp meat from being pushed off the sides of the narrow conveyors 308 by the push rods would not be used. The end effectors 320 can be oriented to push either heads or abdomens off the side of the narrow conveyors 308 by the action of the push rods or by pushing with the bumpers. Or an air jet on the end effector could be used as a pusher.

[0065] Although the invention has been described in detail with respect to a few versions in the process of deheading shrimp, the robotic deheader is usable in other applications, such as portioning pieces of fish, poultry, or other meat products by replacing the bumpers with slicing blades, for example.

Claims

What is claimed is:

1. An automated shrimp deheading system comprising: a support surface configured to support a shrimp having a head helmeted by a carapace and an abdomen joined to the head at a junction that extends between first and second lateral sides from a dorsal side to a ventral side at which legs extend from the head, wherein the first lateral side lies on the support surface and the second lateral side faces upward; a visioning system producing images of the shrimp on the support surface to pinpoint their positions and orientations; a controller executing software program steps to process the images and produce control signals corresponding to the positions and orientations of the shrimp; a robotic deheader including: a vertical arm having an end effector at a lower end of the vertical arm, wherein the end effector includes a bumper; a positioning and orienting mechanism coupled to the vertical arm and configured to selectively position the vertical arm parallel to the support surface in response to control signals from the controller and to orient the end effector about an axis transverse to the support surface in response to control signals from the controller; a bumper actuator coupled to the end effector and configured to selectively thrust the bumper downward toward the support surface in response to control signals from the controller; wherein the positioning and orienting mechanism positions the end effector so that the bumper is positioned above the shrimp and oriented so as to impact the shrimp from the second lateral side along the carapace when the bumper is thrust downward by the bumper actuator to break the junction of the head and the abdomen.

2. The automated shrimp deheading system as claimed in claim 1 wherein the bumper has a lower line of initial contact that the positioning and orienting mechanism align with a deheading line on the second lateral side of the carapace of each of the shrimp parallel toa line extending from a notch at the dorsal side of the junction to the shrimp's legs closer to the abdomen.

3. The automated shrimp deheading system as claimed in claim 2 wherein the bumper has a rounded bottom defining the line of initial contact.

4. The automated shrimp deheading system as claimed in claim 3 wherein the rounded bottom of the bumper flattens upon impact and applies oppositely directed forces that tend to push the head away from the abdomen.

5. The automated shrimp deheading system as claimed in claim 2 wherein the bumper includes a lower cylindrical portion having a major central axis parallel to the support surface.

6. The automated shrimp deheading system as claimed in claim 1 wherein the bumper is made of a material that is resilient enough to deform upon impact with the shrimp and recover its original shape when out of contact with the shrimp.

7. The automated shrimp deheading system as claimed in claim 6 wherein the bumper is made of urethane or rubber.

8. The automated shrimp deheading system as claimed in claim 1 wherein the end effector includes at least one resilient pillow to restrain the head and / or the abdomen when the bumper impacts the shrimp.

9. The automated shrimp deheading system as claimed in claim 1 wherein the end effector includes a pair of resilient pillows flanking the bumper to restrain the head and the abdomen when the bumper impacts the shrimp.

10. The automated shrimp deheading system as claimed in claim 9 wherein the pillows are tent-shaped.

11. The automated shrimp deheading system as claimed in claim 9 wherein the pillows and the bumpers are removably attached to the end effector by attachment structure.

12. The automated shrimp deheading system as claimed in claim 1 wherein the support surface is on a moving conveyor belt.

13. The automated shrimp deheading system as claimed in claim 1 wherein the robotic deheader includes a pusher and a pusher actuator coupled to the pusher and configured to extend the pusher against the abdomen of the shrimp after the junction between the head and the abdomen is broken to separate the abdomen from the severed shrimp.

14. The automated shrimp deheading system as claimed in claim 13 wherein the robotic deheader includes a pillow coupled to the pusher actuator to move with the pusher and to restrain the abdomen while the pusher pushes the abdomen.

15. The automated shrimp deheading system as claimed in claim 13 wherein the pusher is a flexible rod coupled to the pusher actuator.

16. The automated shrimp deheading system as claimed in claim 15 wherein the bumper has a tunnel therethrough and wherein the pusher actuator extends the pusher through the tunnel into contact with the shrimp abdomen to separate the abdomen from the severed head.

17. The automated shrimp deheading system as claimed in claim 15 wherein the cross section of the flexible rod has an inverted U shape with a flat bottom.

18. The automated shrimp deheading system as claimed in claim 13 wherein the robotic deheader includes a left-side bumper coupled to a left-side bumper actuator and a rightside bumper actuator coupled to a right-side bumper actuator and wherein the left-side bumper has a bottom with a ridge configured to conform to and dehead left-side-up shrimp and wherein the right-side bumper has a bottom contoured with a ridge configured to conform to and dehead right-side-up shrimp.

19. The automated shrimp deheading system as claimed in claim 18 wherein the ridge on the bottom of the right-side bumper is the mirror image of the ridge on the bottom of the left-side bumper.

20. The automated shrimp deheading system as claimed in claim 18 wherein the ridges on the bottoms of the right-side and left-side bumpers are non-collinear.

21. The automated shrimp deheading system as claimed in claim 20 wherein the ridges on the bottoms of the right-side and left-side bumpers have multiple segments and wherein some of the segments together form a V to avoid severing throat meet from the abdomen.

22. The automated shrimp deheading system as claimed in claim 18 wherein the robotic deheader includes: a left-side pusher and a left-side pusher actuator, both associated with the left-side bumper and the left-side bumper actuator;a right-side pusher and a right-side pusher actuator, both associated with the right-side bumper and the right-side bumper actuator.

23. The automated shrimp deheading system as claimed in claim 1 wherein the bumper is made of a rubber material.

24. The automated shrimp deheading system as claimed in claim 1 comprising: a plurality of narrow conveyors separated across gaps and advancing in a conveying direction to a downstream end, wherein the narrow conveyors provide the support surface; a takeaway area below the plurality of narrow conveyors upstream of the downstream end; wherein the end effector includes a pusher to push the heads or the abdomens off the sides of the narrow conveyors and into the takeaway area below after the bumper is thrust downward to break the junction of the head and the abdomen.

25. The automated shrimp deheading system as claimed in claim 24 comprising a plurality of takeaway conveyors in the takeaway area and advancing transverse to the conveying direction of the narrow conveyors to receive and convey the heads or the abdomens for disposal or further processing.

26. The automated shrimp deheading system as claimed in claim 25 comprising an outfeed conveyor receiving either abdomens or heads from the downstream end of the narrow conveyors.

27. The automated shrimp deheading system as claimed in claim 24 comprising a plurality of robotic deheaders, each associated with one of the narrow conveyors.

28. A method for deheading shrimp, the method comprising: conveying shrimp having a head helmeted by a carapace and an abdomen joined to the head at a junction that extends between first and second lateral sides from a dorsal side to a ventral side at which legs extend from the head, wherein the first lateral side lies on a conveyor belt and the second lateral side faces upward; producing images of the shrimp as they pass by on the conveyor belt; determining the orientation and position of each of the shrimp on the conveying surface from the images;tracking the position of the shrimp as they are conveyed by the conveyor belt at a belt speed; moving a robotic deheader including an end effector having a line of initial contact in position above a shrimp to be deheaded; orienting the end effector to align the end effector's line of initial contact with a deheading line on the first lateral side of the carapace parallel to a line extending from a notch at the dorsal side of the junction to the shrimp's legs closer to the abdomen; thrusting the end effector down against the carapace from the second side to impact the shrimp and break the junction between the head and the abdomen.

29. The method as claimed in claim 28 comprising providing the end effector with a bumper made of a resilient material that flattens upon impact with the shrimp on the conveyor belt to apply forces that tend to push the head away from the abdomen.

30. The method as claimed in claim 28 comprising providing the end effector with a bumper made of a rigid material and having a bottom contoured with a ridge having noncollinear segments that break the junction and dehead the shrimp.

31. The method as claimed in claim 30 comprising pushing the abdomen away from the severed head after the junction between the head and the abdomen is broken.

32. The method as claimed in claim 31 comprising restraining the abdomen during the deheading of the shrimp and while the abdomen is being pushed away from the severed head.

33. A robotic shrimp deheader for deheading a shrimp having a head joined to an abdomen at a junction, the deheader comprising: a vertical arm having an end effector at a lower end of the vertical arm, wherein the end effector includes a bumper; a translator coupled to the vertical arm and configured to selectively translate the vertical arm in a plane; a rotator coupled to the vertical arm and configured to selectively rotate the vertical arm about an axis transverse to the plane; a bumper actuator coupled to the end effector and configured to selectively thrust the bumper downward;wherein the translator and the rotator position the end effector so that the bumper is positioned above a shrimp and oriented so as to impact the shrimp when the bumper is thrust downward by the bumper actuator against the shrimp to break the junction of the head and the abdomen.

34. The robotic shrimp deheader as claimed in claim 33 wherein the bumper has a rounded bottom defining the line of initial contact.

35. The robotic shrimp deheader as claimed in claim 33 wherein the bumper is made of a material that is resilient enough to deform upon impact with the shrimp and recover its original shape when out of contact with the shrimp.

36. The robotic shrimp deheader as claimed in claim 33 wherein the end effector includes a pair of resilient pillows flanking the bumper to restrain the head and the abdomen when the bumper impacts the shrimp.

37. The robotic shrimp deheader as claimed in claim 33 wherein the robotic deheader includes a pusher and a pusher actuator coupled to the pusher and configured to extend the pusher against the abdomen of the shrimp after the junction between the head and the abdomen is broken to separate the abdomen from the severed shrimp.

38. The robotic shrimp deheader as claimed in claim 37 wherein the robotic deheader includes a pillow coupled to the pusher actuator to move with the pusher and to restrain the abdomen while the pusher pushes the abdomen.

39. The robotic shrimp deheader as claimed in claim 37 wherein the pusher is a flexible rod coupled to the pusher actuator.

40. The robotic shrimp deheader as claimed in claim 39 wherein the bumper has a tunnel therethrough and wherein the pusher actuator extends the pusher through the tunnel into contact with the shrimp abdomen to separate the abdomen from the severed head.

41. The robotic shrimp deheader as claimed in claim 37 wherein the robotic deheader includes a left-side bumper coupled to a left-side bumper actuator and a right-side bumper actuator coupled to a right-side bumper actuator and wherein the left-side bumper has a bottom with a ridge configured to conform to and dehead left-side-up shrimp and wherein the right-side bumper has a bottom contoured with a ridge configured to conform to and dehead right-side-up shrimp.

42. The robotic shrimp deheader as claimed in claim 41 wherein the ridge on the bottom of the right-side bumper is the mirror image of the ridge on the bottom of the left-side bumper.

43. The robotic shrimp deheader as claimed in claim 41 wherein the ridges on the bottoms of the right-side and left-side bumpers are non-collinear.

44. The robotic shrimp deheader as claimed in claim 43 wherein the ridges on the bottoms of the right-side and left-side bumpers have multiple segments and wherein some of the segments together form a V to avoid severing throat meet from the abdomen.

45. The robotic shrimp deheader as claimed in claim 41 wherein the robotic deheader includes: a left-side pusher and a left-side pusher actuator, both associated with the left-side bumper and the left-side bumper actuator; a right-side pusher and a right-side pusher actuator, both associated with the right-side bumper and the right-side bumper actuator.

46. The robotic shrimp deheader as claimed in claim 33 wherein the bumper is made of a rubber material.

47. An automated shrimp deheading system comprising: a plurality of narrow conveyors spaced apart across gaps and conveying shrimp in a conveying direction to a downstream end of the narrow conveyors; one or more takeaway conveyors below the narrow conveyors upstream of the downstream end configured to advance transverse to the conveying direction of the narrow conveyors; a robotic deheader separating the heads from the abdomens of the shrimp on the plurality of narrow conveyors and pushing the heads or the abdomens off sides of the narrow conveyors and onto the one or more takeaway conveyors below; an outfeed conveyor at the downstream end of the narrow conveyors receiving shrimp heads or abdomens not pushed off onto the takeaway conveyors.

48. The automated shrimp deheading system as claimed in claim 47 wherein the robotic deheader is configured to push only detached shrimp heads off the sides of the narrow conveyors onto the takeaway conveyors for disposal or other use.

49. The automated shrimp deheading system as claimed in claim 48 wherein the outfeed conveyor conveys the shrimp abdomens to further processing.

50. The automated shrimp deheading system as claimed in claim 47 comprising a plurality of the deheaders, each deheading shrimp on an associated one of the narrow conveyors.

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