Abstract
In a roller conveyor system in which a product is being conveyed on rollers, a rotational arrestor may be used to dampen and/or stop rotation of rollers after a camera captures an image of the product where such image will be used to predict a location of the product at a subsequent time for picking or other manipulation. The rotational arrestor may comprise a shortened or limited-length traction bar that allows the rotational friction of the rollers to dampen and/or stop rotation of the rollers when the traction bar is not interacting with the rollers.
Claims
1. A roller conveyor system comprising: a track comprising a roller rotation segment and a roller non-rotation segment; two rollers configured to move along the track in a movement direction and in sufficient proximity to each other to directly support an item between them; a sensor device having a data capture area comprising at least some of the path that the two rollers cover as they move along a segment of the track; an item manipulation device configured to manipulate the item in an area that is, according to the movement direction, after the roller rotation segment; and a processing module; wherein: the sensor device is configured to capture both (i) at least two rotating images (rotating images) of the item in the roller-rotation segment of the track and (ii) a second image (second captured image) of the item after the roller rotation segment of the track; the processing module is configured to determine, based on the rotating images, the second captured image, and on movement of the two rollers along the track: (i) an item manipulation location in or after (according to the movement direction) the roller non-rotation segment and (ii) an item manipulation time; and the processing module is further configured to direct the item manipulation device to manipulate the item at the item manipulation location at the item manipulation time.
2. The roller conveyor system of claim 1, further comprising a rotation inducer configured to induce rotation of the two rollers in the roller rotation segment of the track.
3. The roller conveyor system of claim 2, wherein the rotation inducer is a traction bar.
4. The roller conveyor system of claim 3, wherein the traction bar extends in the movement direction to the end of the roller rotation segment and does not extend into the roller non-rotation segment.
5. The roller conveyor system of claim 4, wherein the rotational friction of the two rollers is sufficient to decrease or arrest rotation of the two rollers when not in contact with the traction bar.
6. The roller conveyor system of claim 1, further comprising a rotational arrestor to decrease or arrest rotation of the two rollers in the roller non-rotation segment.
7. The roller conveyor system of claim 6 wherein the rotational arrestor is a brake.
8. The roller conveyor system of claim 1, wherein the item manipulation device is a picker.
9. The roller conveyor system of claim 1, wherein the sensor device is a camera.
10. The roller conveyor system of claim 1, further comprising a traction bar configured to induce rotation of the two rollers in the roller rotation segment; wherein: the traction bar extends in the movement direction to the end of the roller rotation segment and does not extend into the roller non-rotation segment; the rotational friction of the two rollers is sufficient to decrease or arrest rotation of the two rollers when not in contact with the traction bar; the item manipulation device is a picker; and the sensor device is a camera.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIGS. 1A-J show overhead-perspective time snapshots of products being conveyed along a prior art embodiment of a roller conveyor system.
(2) FIG. 1K shows a side view of the system and products depicted in FIG. 1A.
(3) FIGS. 2A-J show side-view-perspective time snapshots of an exemplary system as described herein.
(4) FIGS. 3A-J show overhead-perspective time snapshots of an exemplary system as described herein.
(5) FIGS. 4A-J show side-view-perspective time snapshots of an exemplary system as described herein.
(6) FIGS. 5A-J show overhead-perspective time snapshots of an exemplary system as described herein.
(7) FIG. 6 shows a flowchart for an exemplary method as described herein.
DETAILED DESCRIPTION OF THE INVENTION
(8) This Application claims priority to U.S. Provisional Application No. 63/212,496, titled STABLE POSITIONING OF PRODUCT FOR ROBOTIC PICKING OFF ROLLER TABLE, the first inventor of which is Daniel Goodrick, filed on Jun. 18, 2021, and which is incorporated herein by reference in its entirety.
(9) A system and method are disclosed for arresting roller rotation to avoid product drift and/or roller jumping to facilitate successful picking of a product.
(10) Table of Reference Numbers from Drawings:
(11) The following table is for convenience only and should not be construed to supersede any potentially inconsistent disclosure herein.
(12) TABLE-US-00001 Reference Number Description 100 anti-drift system 101 camera 102 field of view for camera 101 103a-b products 104 rotation inducer 105a-n rollers 106 picker 108 rollers in contact with traction bar 110 track 111 arrow indicating direction of movement of rollers along track 115 arrows indicating rotational direction of rollers 150 rotational arrestor 175 arrows indicating rotational direction of rollers 180 phantom product 200 picker system 600 method flowchart 610 method step 620 method step 630 method step 640 method step 650 method step 660 method step 670 method step 680 method step
(13) As shown in FIGS. 2A-3J, anti-drift/jump system 100 may comprise track 110 configured to convey rollers 105a-n in direction 111, camera 101, field of view 102 of camera 101, rotation inducer 104, picker 106, and rotation arrestor 150. FIGS. 2A-J show a side/cross section view of anti-drift/jump system 100. FIGS. 3A-J show a top-down view of anti-drift/jump system 100. FIGS. 4A-J and 5A-J show an anti-drift/jump system in which rotation arrestor 150 comprises a shortened traction bar 104, using the rotational friction of rollers 105a-n to dampen/arrest/stop rotation of rollers 105a-n.
(14) Computer vision system 101 may be a camera or other sensor with image recognition and image processing capabilities (or other capabilities for processing captured data), and a field of view 102. Camera 101 may be mounted (at least the image capture component) above track 110 and rollers 105a-n, or in some location such that field of view 102 of camera 101 includes at least some of rollers 105a-n. In some embodiments, camera 101 may comprise multiple sensor devices that coordinate and/or work in conjunction with each other.
(15) Robot picker arm 106 may be any robotic or automated device for picking, kicking, striking, or otherwise manipulating a product on rollers 105a-n table. Picker arm 106 may be mounted above, to the side, or otherwise within sufficient proximity of track 110 and rollers 105a-n.
(16) Rotation inducer 104 may be any device for inducing, forcing, or compelling some or all of rollers 105a-n to roll or rotate. Rotation inducer 104 may be one or more traction bars or motors. As shown in FIGS. 2A-J and 4A-J, rotation inducer 104 may be a traction bar, which may contact and mechanically interact with rollers 105a-n as they pass traction bar 104, thereby causing rollers 105a-n to rotate in the direction as indicated by arrows 115 and 175. The spinning/rotation of rollers 105a-n results in rolling and/or re-orientation of products 103a and 103b while in camera 101's field of view 102, thereby allowing camera 101 to image and inspect products 103a and 103b from multiple angles and at multiple orientations.
(17) As shown in FIGS. 2A-3J, a rotational arrestor 150 may arrest, stop, and or dampen rotation of one or more rollers while the product supported by such roller(s) is still in field of view 102 of camera 101 or shortly after the product has supported by such rollers has exited field of view 102 of camera 101. Rotational arrestor 150 may comprise one, or a combination of, many different mechanical systems, e.g., friction, brakes, and/or motors.
(18) In another embodiment, the rotational arrestor may rely on the rotational friction of the rollers such that dampening, arresting, and/or stopping rotation of the rollers is accomplished by not inducing rotation instead of by affirmatively stopping or braking the rotation. For example, as shown in FIGS. 4A-5J, the rotational arrestor may comprise a shortened traction bar 104 that does not interact with rollers 105a-n in a manner to induce rolling in the section of track 110 between the edge of field of view 102 and the location of potential picking by picker 106. In this embodiment, the length/extent of traction bar 104 may be determined based on the location(s) at which camera 101 will capture image(s) of a product such that rotation of rollers 105a-n stops sufficiently soon after exiting field of view 102 so that potential shifting or jumping is within acceptable tolerances.
(19) In some embodiments, the rotation/spinning of a roller 105n may stop completely while a supported product is still in (in completely or partially) camera 101's field of view 102. In other embodiments, rotation/spinning of roller 105n may be limited to acceptable tolerances to prevent, or significantly decrease the likelihood of, significant drifting and/or jumping of products 103a and 103b that may result in an inaccurate predicted location for picking by robot arm 106.
(20) As a point of clarification, the significant location for discontinuing (completely or partially) roller spinning is not necessarily the edge of camera 101's field of view 102, but is, more accurately, determined based on the product location at which camera 101 captures some image or data that will be used to predict the product's subsequent location for picking.
(21) FIGS. 2A-5J show an exemplary embodiment of the anti-drift/jump system 100. FIGS. 2A-J and 4A-J correspond with FIGS. 3A-J and 5A-J, respectively, and represent different views of the same system at times t.sub.1-t.sub.10. FIGS. 2A-J and 4A-J are side/cross-section views. FIGS. 3A-J and 5A-J are top-down views.
(22) All references below to FIGS. 2A-J apply similarly to FIGS. 4A-J, except that FIGS. 4A-J do not include an affirmative rotational arrestor 150. All references below to FIGS. 3A-J apply similarly to FIGS. 5A-J, except that FIGS. 5A-J do not include an affirmative rotational arrestor 150.
(23) As shown in FIGS. 2A and 3A, at time t.sub.1, track 110 is moving rollers 105a-n in direction 111. At time t.sub.1, rollers 105b-g are in field of view 102 of camera 101. Additionally, as shown in FIG. 2A, traction bar 104 is causing rollers 105b-g to rotate in direction 115 (FIGS. 2A-J)/175 (FIGS. 3A-J). Additionally, as shown in FIGS. 2A-3J, rotational arrestor 150 is arresting the rotation of the roller at the boundary of view 102. In FIGS. 2A and 3A, rotational arrestor 150 is arresting the rotation of roller 105h. At time t.sub.1, products 103a and 103b are in the respective locations shown in FIGS. 2A and 3A. More specifically, product 103a is between rollers 105b and 105c, and product 103b is between rollers 105c and 105d. Because rollers 105b, 105c, and 105d are rotating, products 103a and 103b are also rotating, tumbling, and/or rolling.
(24) As shown in FIGS. 2B and 3B, at time t.sub.2 product 103a has been re-oriented since time t.sub.1 (e.g., by rotating, tumbling, and/or rolling), remains between rollers 105b and 105c, and has moved in direction 111 as carried by rollers 105b and 105c. At time t.sub.2 product 103b has been re-oriented since time t.sub.1 (e.g., by rotating, tumbling, and/or rolling), remains between rollers 105c and 105d, and has moved in direction 111 as carried by rollers 105c and 105d. At time t.sub.2 products 103a and 103b are both in field of view 102. Because of product 103a's shape, topography, weight distribution, and/or other features, when product 103a rolls as a result of the rotation of rollers 105b and 105c, product 103a also drifts along the boundary between rollers 105b and 105c. FIGS. 3A-F show that product 103a is drifting downward (toward the bottom of the page/drawing) from times t.sub.1-t.sub.6.
(25) As shown in FIGS. 2C and 3C, at time t.sub.3 product 103a has been re-oriented since time t.sub.2 (e.g., by rotating, tumbling, and/or rolling), remains between rollers 105b and 105c, and has moved in direction 111 as carried by rollers 105b and 105c. At time t.sub.3 product 103b has been re-oriented since time t.sub.2 (e.g., by rotating, tumbling, and/or rolling), remains between rollers 105c and 105d, and has moved in direction 111 as carried by rollers 105c and 105d. At time t.sub.3 products 103a and 103b are both in field of view 102. At time t.sub.3 product 103a has drifted downward since time t.sub.2.
(26) As shown in FIGS. 2D and 3D, at time t product 103a has been re-oriented since time t.sub.3 (e.g., by rotating, tumbling, and/or rolling), remains between rollers 105b and 105c, and has moved in direction 111 as carried by rollers 105b and 105c. At time t.sub.4 product 103b has been re-oriented since time t.sub.3 (e.g., by rotating, tumbling, and/or rolling), remains between rollers 105c and 105d, and has moved in direction 111 as carried by rollers 105c and 105d. At time t.sub.4 products 103a and 103b are both in field of view 102. At time t.sub.4 product 103a has drifted downward since time t.sub.3.
(27) As shown in FIGS. 2E and 3E, at time is product 103a has been re-oriented since time t.sub.4 (e.g., by rotating, tumbling, and/or rolling), remains between rollers 105b and 105c, and has moved in direction 111 as carried by rollers 105b and 105c. At time is product 103b has been re-oriented since time t.sub.4 (e.g., by rotating, tumbling, and/or rolling), remains between rollers 105c and 105d, and has moved in direction 111 as carried by rollers 105c and 105d. At time is product 103a remains in field of view 102 but product 103b is no longer in field of view 102. Additionally, at time t.sub.5 rotation arrestor 150 has arrested the rotation of roller 105d, which is one of rollers supporting product 103b. At time t.sub.5 product 103a has drifted downward since time t.sub.4.
(28) As shown in FIGS. 2F and 3F, at time t.sub.6 product 103a has been re-oriented since time t.sub.5 (e.g., by rotating, tumbling, and/or rolling), remains between rollers 105b and 105c, and has moved in direction 111 as carried by rollers 105b and 105c. At time is product 103a has drifted downward since time t.sub.5. At time t.sub.6 rotation of rollers 105c and 105d has been arrested by rotation arrestor 150. At time t.sub.6 product 103b has not been re-oriented since time is because rotation of rollers 105c and 105d has been arrested. Product 103b remains between rollers 105c and 105d and has moved in direction 111 as carried by rollers 105c and 105d.
(29) As shown in FIGS. 2G and 3G, at time t.sub.7 neither of products 103a and 103b has been re-oriented since time t.sub.6 because rotation of rollers 105b, 105c, and 105d has been arrested by rotation arrestor 150. Because product 103a has not rotated since time t.sub.6, it has also not drifted since time t.sub.6. Product 103a remains between rollers 105b and 105c and has moved in direction 111 as carried by rollers 105b and 105c. Product 103b remains between rollers 105c and 105d and has moved in direction 111 as carried by rollers 105c and 105d.
(30) As shown in FIGS. 2H and 3H, at time t.sub.8 neither of products 103a and 103b has been re-oriented since time t.sub.7 because rotation of rollers 105b, 105c, and 105d has been arrested by rotation arrestor 150. Product 103a has not drifted since time t.sub.7. Product 103a remains between rollers 105b and 105c and has moved in direction 111 as carried by rollers 105b and 105c. Product 103b remains between rollers 105c and 105d and has moved in direction 111 as carried by rollers 105c and 105d.
(31) As shown in FIGS. 2I and 3I, at time ty neither of products 103a and 103b has been re-oriented since time t.sub.8 because rotation of rollers 105b, 105c, and 105d has been arrested by rotation arrestor 150. Product 103a has not drifted since time t.sub.8. Product 103a remains between rollers 105b and 105c and has moved in direction 111 as carried by rollers 105b and 105c. Product 103b remains between rollers 105c and 105d and has moved in direction 111 as carried by rollers 105c and 105d.
(32) As shown in FIGS. 2J and 3J, at time t.sub.10 neither of products 103a and 103b has been re-oriented since time tv because rotation of rollers 105b, 105c, and 105d has been arrested by rotation arrestor 150. Product 103a has not drifted since time t.sub.9. Product 103a remains between rollers 105b and 105c and has moved in direction 111 as carried by rollers 105b and 105c. Product 103b remains between rollers 105c and 105d and has moved in direction 111 as carried by rollers 105c and 105d. At time t.sub.10 system 100 is able to use picker 106 to accurately predict (or has previously accurately predicted) the location of product 103a and pick product 103a because product 103a's location along the boundary between rollers 105b and 105c was determined based on an image captured by camera 101 at a time when product 103a was in camera 101's field of view 102, and product 103a did not significantly drift since that time along the boundary between rollers 105b and 105c. System 100 may determine the location at time t.sub.10 of the boundary between rollers 105b and 105c along track 110 by using information about the speed/movement profile of track 110 and/or rollers 105a-n along track 110, or by using a linear encoder, or by any other means for determining linear movement and/or location known in the art. The initial location of the product or item, e.g., product 103a, may be determined using image recognition/processing techniques on an image captured by camera 101 and processed by system 100.
(33) Method
(34) FIG. 6 shows a flowchart for an exemplary method for avoiding (and/or mitigating) drift and/or jumping, and thereby facilitating successful picking using a system as disclosed herein as shown in FIGS. 2A-5J.
(35) At step 610, system 100 may move rollers 105b and 105c, which are supporting a product 103a, along a track 110.
(36) At step 620, system 100 may induce rotation of at least roller 105b. In one embodiment, a traction bar may be used to induce rotation.
(37) At step 630, system 100 may use camera 101 to capture an image of product 103a.
(38) At step 640, system 100 may use a rotational arrestor to arrest rotation of roller 105b. Alternatively, system 100 may allow cessation of rotation to occur by rotational friction in the rollers.
(39) At step 650, system 100 may use a camera to capture a second image of product 103a.
(40) At step 660, system 100 may determine to use a picker 106 to pick product 103a.
(41) At step 670, system 100 may use the second image of product 103a to determine a time and location to use picker 106 to pick product 103a.
(42) At step 480, system 100 may use picker 106 to pick product 103a at the determined time and location.
