The present disclosure relates generally to trays for robot part handling and more particularly to grid trays that are configurable to provide various grid patterns for positioning workpieces.
It is known to automatically “pick and place” workpieces from a workpiece tray to a holding fixture (such as a vice or chuck) in a machine tool (such as a CNC machine) using a robotic arm.
The purpose of arranging the workpieces 27 in a regular array in grid tray 18 is to simplify programming of robot 12 and to separate the parts to provide space for the gripper fingers 26 to access the workpieces 27 without interfering with neighboring workpieces. The regular array provides a simple way for operators to load grid tray 18 and accurately place the workpieces for robot 12, which is critical to ensure that robot 12 loads the workpiece 27 into holding fixture 22 (e.g., a pneumatic vise) accurately for machining. The operator loads grid tray 18 by placing a workpiece 27 in a pocket 28 and pushing the workpiece to a corner of pocket 28, which ensures the workpiece is accurately placed in each pocket 28. The process is simple and does not require precise locating and alignment by the operator to fill grid tray 18.
The main limitation of the fixed-array grid tray concept is that it is limited to one pocket dimension and is only optimized for a single size of workpieces. Most conventional grid trays are not configurable to accept workpieces of different sizes. To optimize the capacity for different sized workpieces, each workpiece size requires a different fixed-array grid tray to be designed for the pocket size to match the part size closely, manufactured, installed, and calibrated. Similarly, if a subsequent manufacturing job's workpieces are larger than the pocket dimensions of the current grid tray, then a new grid tray with larger pockets would need to be manufactured.
One existing grid tray 30 design that permits optimization of workpiece capacity of a fixed surface area provides an array of peg or tapped holes 31 as shown in
While it is possible to carefully position workpieces 27 on a part tray surface that has been laser engraved or otherwise marked with a regular array of grid lines using the grid lines as a guide, such an approach would require far more time and precision work by the operator to load workpieces 27 than a conventional grid tray design. Moreover, any mistake in the positioning a workpiece 27 may result in a collision with robot gripper 16.
It is also possible to achieve variable capacity by eliminating the fixed array approach entirely. Instead, in robotic bin picking, for example, as shown in
According to one embodiment, the present disclosure provides a configurable tray for robot workpiece handling, comprising: a frame including a plurality of frame segments arranged in a rectangle, each of the plurality of frame segments including a plurality of positioning features spaced evenly along an inner edge of the frame segment; and a plurality of separation bars, each separation bar including a first end and a second end and configured to be selectively positioned within the frame such that the first end is positioned at a positioning feature of one of the frame segments and the second end is positioned at a positioning feature of another of the frame segments opposite the one of the frame segments; wherein the plurality of separation bars are configured to be positioned to define one or more configurable grid patterns of pockets for receiving a workpiece by selectively positioning a first number of the plurality of separation bars between positioning features of a first pair of opposed frame segments of the plurality of frame segments and selectively positioning a second number of the plurality of separation bars overlapping the first number of the plurality of separation bars between positioning features of a second pair of opposed frame segments of the plurality of frame segments, the first pair of segments being perpendicular to the second pair of segments. In one aspect of this embodiment, the plurality of positioning features each includes a notch disposed between adjacent protrusions formed along the inner edge of the segment of the frame. Another aspect of this embodiment further includes a base, the frame being attached to the base. In a variant of this aspect, the base includes a pair of end plates and a plurality of inner plates. In a further variant, the pair of end plates and the plurality of inner plates are configured to interlock to form the base. In another aspect of this embodiment, the plurality of frame segments includes a pair of side segments and a pair of end segments. In a variant of this aspect, each of the pair of side segments includes a first end forming a first notch and a second end forming a second notch, and each of the pair of end segments includes a first end forming a first tab and a second end forming a second tab, the first notches being configured to mate with the first tabs and the second notches being configured to mate with the second tabs, thereby connecting the pair of side segments to the pair of end segments to form the frame. Yet another aspect of this embodiment further includes a pair of locking plates, each locking plate being attached to one of the plurality of frame segments and including an inner portion that overlaps the ends of the second number of the plurality of separation bars to clamp the plurality of separation bars in place. A variant of this aspect further includes a base attached to the frame and including a pair of end plates and a plurality of inner plates, wherein the plurality of frame segments, the plurality of separation bars, the pair of end plates, the plurality of inner plates, and the pair of locking plates are substantially the same length and substantially the same width. Still another aspect of this embodiment further includes a plurality of height adjustment brackets and a plurality of clips, wherein each height adjustment bracket is positioned adjacent a corner of the frame and includes a plurality of horizontal slots, and each of the plurality of clips is configured to extend through a pair of the plurality of horizontal slots and clip onto a frame segment, thereby supporting the frame at a selectable height above a support surface. In a variant of this aspect, each of the plurality of height adjustment brackets includes a mounting plate configured to attach to the support surface and an upright plate including the plurality of horizontal slots.
In another embodiment, the present disclosure provides a robotic machine tending system, comprising: a robot having at least one gripper for gripping a workpiece; a controller configured to execute job manager software to control movement of the robot; and a configurable tray configured to hold workpieces in one or more grid patterns of pockets; wherein the configurable tray comprises: a frame including a plurality of frame segments including a plurality of positioning features spaced evenly along an inner edge of the frame segment; and a plurality of separation bars configured to be selectively positioned within the frame to define the one or more grid patterns of pockets by selectively positioning a first number of the plurality of separation bars between positioning features of a first pair of opposed frame segments of the plurality of frame segments and selectively positioning a second number of the plurality of separation bars overlapping the first number of the plurality of separation bars between positioning features of a second pair of opposed frame segments of the plurality of frame segments, the first pair of frame segments being perpendicular to the second pair of frame segments. In one aspect of this embodiment, the plurality of positioning features each includes a notch disposed between adjacent protrusions formed along the inner edge of the frame segment. In another aspect, the configurable tray further includes a base, the frame being attached to the base. In a variant of this aspect, the base includes a pair of end plates and a plurality of inner plates, the pair of end plates and the plurality of inner plates being configured to interlock to form the base. In yet another aspect, the plurality of frame segments includes a pair of side segments and a pair of end segments configured to mate with the pair of side segments to form the frame. In still another aspect of this embodiment, the configurable tray further includes a pair of locking plates, each locking plate being attached to one of the plurality of frame segments and including an inner portion that overlaps ends of the second number of the plurality of separation bars to clamps the plurality of separation bars in place. In a variant of this aspect, the configurable tray further includes a base attached to the frame and including a pair of end plates and a plurality of inner plates, wherein the plurality of frame segments, the plurality of separation bars, the pair of end plates, the plurality of inner plates, and the pair of locking plates are substantially the same length and substantially the same width. In another aspect of this embodiment, the configurable tray further includes a plurality of height adjustment brackets and a plurality of clips, wherein each height adjustment bracket is positioned adjacent a corner of the frame and includes a plurality of horizontal slots, and each of the plurality of clips is configured to extend through a pair of the plurality of horizontal slots and clip onto a frame segment, thereby supporting the frame at a selectable height above a support surface. In still another aspect, the job manager software causes the controller to display one or more grid tray configuration screens to enable an operator to define a number of rows and a number of columns corresponding to each of the one or more grid patterns. In a variant of this aspect, the one or more configuration screens further enable the operator to define a length and a width of each of the one or more grid patterns. In another variant, the one or more configuration screens further enable the operator to define pockets of each of the one or more grid patterns that cannot be accessed by the robot.
In yet another embodiment, the present disclosure provides a method for configuring a tray for robot workpiece handing, comprising: selectively positioning a first plurality of separation bars within a corresponding first plurality of evenly spaced positioning features formed on a first pair of opposing frame segments of a frame; selectively positioning a second plurality of separation bars within a corresponding second plurality of evenly spaced positioning features formed on a second pair of opposing frame segments of the frame, the second pair of opposing frame segments being perpendicular to the first pair of frame segments and the second plurality of separation bars overlapping the first plurality of separation bars; and attaching a pair of locking bars to the second pair of opposing frame segments such that the locking bars overlap ends of the second plurality of separation bars to clamp the second plurality of separation bars in place. One aspect of this embodiment further comprises: assembling a base including a pair of end plates and a plurality of inner plates configured to interlock to form the base; and attaching the frame to the base. In a variant of this aspect, attaching the frame to the base includes positioning the frame above the base and securing the frame to a plurality of height adjustment brackets connected to the base using a plurality of clips.
While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
The above-mentioned and other features of this disclosure and the manner of obtaining them will become more apparent and the disclosure itself will be better understood by reference to the following description of embodiments of the present disclosure taken in conjunction with the accompanying drawings, wherein:
While the present disclosure is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The present disclosure, however, is not to limit the particular embodiments described. On the contrary, the present disclosure is intended to cover all modifications, equivalents, and alternatives falling within the scope of the appended claims.
Referring now to
Frame 112 may be formed as an integral part of base 114. Alternatively, frame 112 may be attached to base 114 using fasteners, welding, adhesive, clamps, or any other type of attachment mechanism. Base 114 may be a rectangular, solid piece of material sized to correspond to outer edges 126 of side segments 118-124 of frame 112. Alternatively, base 114 may have openings formed therethrough or be formed using interlocking segments as described below. In certain embodiments, base 114 may be omitted entirely when, for example, frame 112 is attached to another support surface such as a table.
Separation bars 116 are depicted as elongated strips of material having straight, parallel side edges 136, a straight upper surface 138, a straight lower surface (not shown) that is parallel to upper surface 138, and a pair of ends 140. In one embodiment, the height of side edges 136 is smaller than the width of upper surface 138 and lower surface. In the depicted embodiment, each separation bar 116 is identical to the others. As should be apparent from the foregoing, the ends 140 of separation bars 116 are configured to mate with or otherwise be accurately positioned by bar positioning features 130 of side segments 118-124 of frame 112. In the example shown, separation bars 116 are positioned onto frame 112 horizontally first, and then additional separation bars 116 are positioned onto frame 112 vertically such that they overlap the horizontally positioned separation bars 116. In this manner, separation bars 116 may be positioned to form one or more regular grid patterns such as grid pattern 142 and grid pattern 144 in the example shown. Of course, separation bars 116 may be positioned to form a single grid pattern that spans all or part of base 114 within frame 112. In an alternative embodiment, separation bars 116 may be replaced with narrow rods laid on top of racks commonly found in rack-and-pinion gear sets or even timing belts which provide regular indentations to position the rods.
By positioning separation bars 116 in the manner described above, a plurality of pockets 146 may be formed in a regular grid pattern that facilitates efficient operation and programming of robot 12. For example, grid pattern 142 includes nine equally spaced, rectangular pockets 146A in a three-by-three grid. Grid pattern 144 also includes nine equally spaced, rectangular pockets 146B in a three-by-three grid, although pockets 146B are smaller than pockets 146A and formed to position smaller workpieces.
Regardless of the size of the pocket or workpiece, in this example each workpiece 148 may be precisely and easily located on grid tray 100 by registering the workpiece in a corner of the pocket 146. As an example, in grid pattern 142 three workpieces 148 are shown registered against the upper left corner of pockets 146A such that workpieces 148 are aligned and equally spaced from one another as is provided by conventional, non-configurable grid trays described above.
Referring now to
Frame 212 includes two side segments 218, 220 and two end segments 222, 224. Each side segment 218, 220 includes an outer edge 226 and an inner edge 228 having a plurality of bar positioning features 230 which are the same or similar to bar positioning features 130 described above with reference to grid tray 100. Each side segment 218, 220 also includes a notch 252 formed near each end of the segment along inner edge 228. Each end segment 222, 224 includes an outer edge 254 and an inner edge 256 having a plurality of bar positioning features 230 as described above with reference to grid tray 100. Each end segment 222, 224 also includes a tab 258 extending from each end of the segment and sized to mate with notches 252 of side segments 218, 220 as best shown in
As best shown in
Referring now to
Referring back to
One benefit of the multi-piece design of grid tray 200 is the substantial uniformity of the size of the separate components. Each of side segments 218, 220 and end segments 222, 224 of frame 214, each of end plates 262, 264 and the plurality of inner plates 266 of base 214, separation bars 216 and locking plates 250 are elongated, substantially flat components of substantially the same length. As such, all of the components may be efficiently packaged together in a relatively small, densely packed container to minimize shipping costs.
Yet a further embodiment of grid tray 200 is shown in
The embodiments of grid tray 100, 200 disclosed herein may be used in a variety of applications such as in drawer systems and table systems, or any other workpiece presentation surface.
In certain embodiments, robot 12 is controlled to operate with configurable grid tray 200 by a job manager software control system (hereinafter, “job manager software”) executed by a controller, which could be a controller 25 of CNC machine 24 (
An operator can measure and store the calibration of grid tray 200 configuration using gripper fingers 26 of robot 12, for example, by measuring three corner points of grid tray 200 and adjusting the measured points based on the width and length of the fingers 26 which are used as the calibration device as described below. The robot end of arm position is computed using the joint encoder locations to calculate the three corner points relative to the robot base coordinate system.
The operator can also update or define the actual length and width of pockets 146 of grid tray 200 by filling in fields 362 and 364 and clicking on icon 360. Boxes 366 and 368 permit the operator to input the grid dimensions in millimeters or inches, respectively. Finally, the operator may save the drawer configuration by clicking on icon 370 and proceed to define the next drawer. Icon 372 permits the operator to load a previously defined drawer configuration stored on memory accessible by controller 25.
Referring now to
The three-corner point calibration discussed above is further described with reference to
Corner1x=P1x−Finger Calibration Offsetx·{right arrow over (x)}dir
Corner1y=P1y−Finger Calibration Offsety·{right arrow over (y)}dir
Corner2x=P2x+Finger Calibration Offsetx·{right arrow over (x)}dir
Corner2y=P2y−Finger Calibration Offsety·{right arrow over (y)}dir
Corner3x=P3x−Finger Calibration Offsetx·{right arrow over (x)}dir
Corner3y=P3y+Finger Calibration Offsety·{right arrow over (y)}dir
Knowing the directions for X and Y, the actual corners of grid tray 200 can be computed by adding and subtracting the width and length of fingers 26 for each of the three points in the corresponding X and Y directions. This gives the three corner points of grid tray 200 relative to the robot base coordinate system. Given the pocket width and length and the number of pockets in grid tray 200 shown in
Given the X and Y locations of each grid pattern of grid tray 200 and the number of pockets 146 in the rows and columns of each grid pattern, controller 25 can show the available pockets 146 and the operator can select to place workpieces 148 in the available pockets 146. This capability of setting the pocket sizes to different dimensions throughout grid tray 200 allows the operator to optimize the available surface area for different size workpieces 148 for unattended robot tending of different batches of workpieces 148.
According to one feature of the present disclosure, controller 25 permits the operator to define segments or pockets 146 that are not to be accessed to avoid interference between robot 12 and workpieces 148 or to avoid commanding robot 12 to access locations which cannot be reached by grippers 16 due to reach or other limitations in the robot's kinematics and gripper configuration.
In situations such as depicted in
In an alternative embodiment, the operator may measure the three corners of grid tray 200 as described above with reference to
Since the bar positioning features 230 are evenly spaced on the grid tray 200, the job manager software can compute the location of any workpiece 148 based on its dimensions and location in the grid tray for robot 12 to pick and place accordingly. In a variation of this embodiment, each bar positioning feature 230 may be numbered on the grid tray with laser etching or otherwise to permit easier identification for entry into the job manager software. Additionally, bar positioning features 230 and the overall dimensions of the grid tray are user-defined parameters in the job manager software.
As used herein, the modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (for example, it includes at least the degree of error associated with the measurement of the particular quantity). When used in the context of a range, the modifier “about” should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the range “from about 2 to about 4” also discloses the range “from 2 to 4.”
It should be understood that the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements. The scope is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” Moreover, where a phrase similar to “at least one of A, B, or C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B or C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C.
In the detailed description herein, references to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art with the benefit of the present disclosure to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments.
Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112(f), unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus
Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present disclosure. For example, while the embodiments described above refer to particular features, the scope of this disclosure also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present disclosure is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof.