Methods of controlling a dispensed bead shape and optimizing a nonlinear robotic trajectory of deposition

Abstract

The present disclosure provides a method of controlling a bead shape of a dispensed bead of material along a dispensing path, by adjusting at least one of a) a robot path parameter or b) a dispenser parameter, using at least one of i) a user input or ii) a feedback from a sensor, to vary the bead shape based on a characteristic of the workpiece. A method of optimizing a non-linear robotic trajectory of deposition of a bead material includes a) obtaining a nominal deposition path; b) selecting at least one process parameter; c) optimizing the deposition path using the at least one process parameter and at least one path or parameter tolerance to create an adjusted deposition path; d) checking for at least one issue along the adjusted deposition path; and e) finalizing the adjusted deposition path. A method of depositing a bead of material in a non-linear path includes optimizing a non-linear robotic trajectory of deposition of a bead material and depositing the bead of material in the finalized adjusted path.

Description

[0001] METHODS OF CONTROLLING A DISPENSED BEAD SHAPE AND OPTIMIZING A NONLINEAR ROBOTIC TRAJECTORY OF DEPOSITION

[0002] BACKGROUND

[0003] Automation capabilities widely exist for robotic modification of workpieces, e.g., application of dispensed adhesives. There is a general need to have greater control of the modification processes.

[0004] SUMMARY OF THE DISCLOSURE

[0005] In a first aspect, a method of controlling a bead shape of a dispensed bead of material along a dispensing path is provided. The method comprises adjusting at least one of a) a robot path parameter or b) a dispenser parameter, using at least one of i) a user input or ii) a feedback from a sensor, to vary the bead shape of the dispensed bead of material based on a characteristic of the workpiece.

[0006] In a second aspect, a method of optimizing a non-linear robotic trajectory of deposition of a bead material is provided. The method comprises a) obtaining a nominal deposition path; b) selecting at least one process parameter; and c) optimizing the deposition path using the at least one process parameter and at least one path or parameter tolerance to create an adjusted deposition path. The method further comprises d) checking for at least one issue along the adjusted deposition path; and e) finalizing the adjusted deposition path.

[0007] In a third aspect, a method of depositing a bead of material in a non-linear path is provided. The method comprises optimizing a non-linear robotic trajectory of deposition of ahead material according to a method of any embodiment according to the second aspect; and depositing the bead of material in the finalized adjusted path.

[0008] The above summary of the present disclosure is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The description that follows more particularly exemplifies illustrative embodiments. In several places throughout the application, guidance is provided through lists of examples, which examples may be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list. Thus, the scope of the present disclosure should not be limited to the specific illustrative structures described herein, but rather extends at least to the structures described by the language of the claims, and the equivalents of those structures. Any of the elements that are positively recited in this specification as alternatives may be explicitly included in the claims or excluded from the claims, in any combination as desired. Although various theories and possible mechanisms may have been discussed herein, in no event should such discussions serve to limit the claimable subject matter.

[0009] BRIEF DESCRIPTION OF FIGURES

[0010] FIG. 1 illustrates a system for modifying a workpiece in which example embodiments can be implemented.

[0011] FIG. 2 illustrates an example system in accordance with embodiments herein. FIGS. 3A-3I illustrate variations to a blending distance in blending two portions of a bead of material at a junction of a head and a tail.

[0012] FIGS. 4A-4B depict an exemplary variation to a gradient thickness to blend two portions of a bead at a junction of a head and a tail.

[0013] FIG. 5 depicts the effect of increasing size of an outer diameter of a dispenser nozzle on the width of a bead of material on a workpiece substrate.

[0014] FIG. 6A depicts a workpiece that requires the deposition of a bead of material along four curved comers of the workpiece.

[0015] FIG. 6B is a photograph of an actual bead of material deposited on a workpiece substrate having gaps between adjacent sections due to the dispenser valve being turned off along portions of the dispensing path.

[0016] FIG. 7 depicts a bottom view of the effects on a width of a bead of material by changing a material feed rate and / or a tool velocity.

[0017] FIGS. 8A-8B depict controlling a bead thickness to compensate for different bonding heights at different locations of a workpiece.

[0018] FIG. 9A depicts a side view of a bead of material deposited on a workpiece substrate, with each section having a smaller thickness than the adjacent section, in the direction of deposition.

[0019] FIG. 9B depicts a top view of the same bead of material from FIG. 9A on the workpiece substrate, showing that the width remains constant regardless of the thickness.

[0020] FIG. 10 is a photograph depicting results of varying material feed rate and tool velocity to achieve variable bead width along a continuous path, as well as graphs of the relative changes in feed rate or tool velocity included next to each portion of the photograph.

[0021] FIG. 11 is a photograph showing how varying a feed rate can affect the width of a bead of material.

[0022] FIGS. 12A-12B depict two exemplary different robot configurations in a robotic workspace.

[0023] FIG. 13 is a flow chart of a method of optimizing a non-linear robotic trajectory of deposition of a bead material in which example embodiments can be implemented.

[0024] FIG. 14 is a flow chart of a method of depositing a bead of material in a non-linear path in which example embodiments can be implemented.

[0025] FIG. 15 depicts a side view of a dispenser nozzle.

[0026] FIGS. 16-17 depict some exemplary adjustments to a path.

[0027] FIG. 18 depicts how adjusting the tolerance value (5) will affect the final path.

[0028] FIG. 19 depicts how varying the applicator width (y) will affect the final path.

[0029] FIG. 20 depicts a sample path trajectory with varying nominal velocity and deposition rate.

[0030] FIG. 21 illustrates an example dispensing system in an example network architecture.

[0031] FIGS. 22-24 illustrate example computing devices that can be used in embodiments herein. FIG. 25 illustrates a schematic showing an adjustment of waypoint location based on the midpoint of rib features within the surface profile scan in accordance with an embodiment described herein.

[0032] FIG. 26 is a photograph of a paper workpiece substrate of Example 1, folded to form a rib on its surface.

[0033] FIGS. 27A-C provide plots of nominal deposition paths and planned deposition paths over time in Example 1.

[0034] FIG. 27D illustrates a map of the scanned surface of the workpiece substrate used in Example 1.

[0035] FIG. 28 A is a photograph of the tapered nozzle used in Example 1.

[0036] FIG. 28B is a photograph of the workpiece substrate of FIG. 26 with a bead deposited on the rib according to the planned deposition toolpath of Example 1.

[0037] FIG. 29A is a photograph of a smear nozzle used in Example 2.

[0038] FIG. 29B is a photograph of a workpiece substrate used in Example 2.

[0039] FIG. 29C illustrates a map of the scanned surface of the workpiece substrate of Example 2.

[0040] FIGS. 29D-F provide plots of planned deposition paths over time in the first experiment of Example 2.

[0041] FIG. 29G provides a plot of planned velocity over time in the first experiment of Example 2.

[0042] FIGS. 29H-I are photographs of the final result of the smear nozzle depositing a bead of material according to the planned deposition toolpath and velocity of the first experiment of Example 2.

[0043] FIGS. 29J-L provide plots of planned deposition paths over time in the second experiment of Example 2.

[0044] FIG. 29M provides a plot of planned velocity over time in the second experiment of Example 2.

[0045] FIGS. 29N-O are photographs of the final result of the smear nozzle depositing a bead of material according to the planned deposition toolpath and velocity of the second experiment of Example 2.

[0046] FIG. 30A is a photograph of a smear nozzle used in Example 3.

[0047] FIG. 30B is a photograph of the effects of changing velocity of bead deposition on a steel substrate according to Example 3.

[0048] FIGS. 30C-30E are photographs of the widths of beads of material at different bead deposition velocities according to Example 3.

[0049] In the drawings, like reference numerals indicate like elements. While the above-identified drawings, which may not be drawn to scale, set forth various embodiments of the present disclosure, other embodiments are also contemplated, as noted in the Detailed Description. In all cases, this disclosure describes the presently disclosed disclosure by way of representation of exemplary embodiments and not by express limitations. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of this disclosure. DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0050] For the following Glossary of defined terms, these definitions shall be applied for the entire application, unless a different definition is provided in the claims or elsewhere in the specification.

[0051] Glossary

[0052] Certain terms are used throughout the description and the claims that, while for the most part are well known, may require some explanation. It should be understood that: “workpiece” refers to any object being worked on with a tool or machine, and the term may be used interchangeably with “part” herein;

[0053] “scan” refers to traversing a point, a line, and / or an area, using equipment;

[0054] “workspace” refers to any area in which a robot operates;

[0055] “robot” refers to a machine configured to carry out physical actions, which includes at least two degrees of freedom (DOF) and up to 7 DOF;

[0056] “degrees of freedom” refers to the number of independent ways a robot (e.g., in some cases, a robot arm) can move, including positions and orientations.

[0057] “singularity” refers to a pose in which all the joints on a robot are at certain positions such that the robot cannot move the tool / end effector along one or more axes, or a point where two or more of a robot’s axes are aligned, leading to ambiguity in motion, which sometimes presents as undesirable infinite joint velocities; and

[0058] “jerk” is defined as the 3rd derivative of joint position trajectory, which is minimized throughout a path to achieve smoothness.

[0059] The present disclosure relates to methods and systems for controlling a bead shape of a dispensed bead of material along a dispensing path, for optimizing a non-linear robotic trajectory of deposition of a bead of material, and for depositing a bead of material in a non-linear path.

[0060] During a robotic dispensing process, there is often a constraint that the velocity of the dispenser nozzle should remain constant throughout the dispensing process. Maintaining a constant velocity along with a constant volumetric flowrate of the dispensed material ensures a consistent cross-sectional area of the dispensed material. Any acceleration events, therefore, need to be closely considered. The main sources of acceleration during a dispensing process occur during initial and final robot motion along a path, as well as any changes of direction. To achieve a direction change, an acceleration must take place in a different direction than the current motion direction. Depending on the magnitude and direction of the acceleration, as well as the nozzle tip velocity, this can cause significant changes to the bead shape. Adjusting the flowrate can help to mitigate some of the bead shape changes, although adjusting the flowrate involves adjusting some physical apparatus that is then subject to its own dynamics of motion and can take some time to reach a new steady-state flowrate.

[0061] One common application of robotic dispensing is applying a material in a closed-loop path on a workpiece or following some non-linear path. As the robot moves to change the direction of travel, an accelerating force is applied to reduce the velocity in previous direction of travel, and an accelerating force is applied along a different vector to increase velocity in the new direction of travel. This is done by applying forces with the robotic motion. Depending on when and how these forces are applied, as well as the path travelled by the dispenser tip, this can change the constant velocity condition. Additionally, the dispensed material can exhibit undesirable shapes, such as bulges (e.g., over-dispensed), thinning (e.g., under-dispensed) and / or ringing (e.g., oscillating lines). This is especially exacerbated when the dispenser must align its orientation with the direction of travel, which occurs when dispensing a non- axially symmetric material shape (i.e., not having a circle-shaped cross-section). Due to the nature of such geometric shapes, changing direction is insufficient, as the cross-sectional area is important to the application. Thus, when designing a robotic path, the change in orientation must also be accounted for. As such, robotic paths created for dispensing processes must account for dynamic limitations as well as process limitations, when accounting for cross-sectional area of deposited material, otherwise the desired final product can contain flaws due to inconsistent travel velocity.

[0062] Additionally, robotic dispensing of a bead of material with precisely controlled bead shape is required to achieve desired bonding and hermetic performance in applications such as sealing gasket on appliance doors and weather strips on automotive windshields. For example, bead shape at the junction of a head and a tail of a bead of material is dependent on multiple factors such as dispenser parameters and robot toolpath parameters. Non-optimal selection of these process parameters could lead to unexpected bead shapes such as a stringing effect with material dragged from the nozzle during a lead-out motion; a lack of or an excess of material at the head / tail junction due to timing mismatch between valve on / off states and starting / stopping of robot motion; and / or non-uniform thickness and width (e.g., a necking effect) caused by a mismatch between a material flow rate and a robot speed. Such problems are particularly noticeable when the viscosity of the material being dispensed is relatively high. In applications where ventilation is required along an adhesive bead (e.g., to avoid over-pressure / explosion of part assemblies with enclosed volume), a uniform bead with a minimum opening at the head-tail junction is needed to allow pressure balancing while maintaining an aesthetic appearance.

[0063] However, a uniform bead shape with constant width and thickness along the bead is not always desirable for all applications. Achieving a customizable bead shape with variable width, thickness, and alternating on / off control is advantageous for the purposes of optimal material distribution on a workpiece to achieve the required bonding strength with minimum material consumption; on-demand bead deposition on just certain locations of part for efficient material usage; avoidance of deposition of material on certain part features; and / or variable bead thickness to compensate for variable bonding height due to part-to-part variation (e.g., dispensing on non-planar workpieces and warped workpieces). A control method to effectively vary bead shape along the robot dispensing path to meet these requirements would be desirable.

[0064] In a first aspect, a method is provided of controlling a bead shape of a dispensed bead of material along a dispensing path. The method comprises adjusting at least one of a) a robot path parameter or b) a dispenser parameter using at least one of i) a user input or ii) a feedback from a sensor, to vary the bead shape of the dispensed bead of material based on a characteristic of the workpiece. It is to be understood that the adjustment can be at any point along a path and may change over time and / or distance. Suitable exemplary workpiece characteristics for which a bead shape may be varied include for instance and without limitation, a change in height, a change in width, a wall, a rib, a seam, an edge, a change in a bonding strength need, a gap in portions needing a bead of material, and a portion where a head and a tail of the bead of material have a junction. In some cases, any of a wall, a rib, a seam, and / or an edge of the workpiece can guide bead placement. In certain embodiments of the present disclosure, the bead is a bead of adhesive (e.g., pressure sensitive adhesive, structural adhesive, etc.), although other materials are expressly contemplated to be dispensed in a form of a bead on a workpiece.

[0065] FIG. 1 illustrates a system in which example embodiments can be implemented. The system 100 includes main components of a controller 110, a sensor system 120, and a dispenser 130. System 100 is illustrated in FIG. 1 as in communication with a data store 140. However, it is expressly contemplated that, in some embodiments, data store 140 may be local to, or integrated into system 100. Similarly, system 100 is illustrated as projecting to a display 10. However, it is expressly contemplated that system may be integrated into a processor of a device that includes display 10. The system 100 may be implemented by one or more suitable computing devices in communication with each of these main components.

[0066] The controller 110 comprises a processor 111 that receives as inputs at least one of feedback from a sensor 121 or a user input. The user input may include for instance and without limitation, one or more of: tool position, tool velocity, tool orientation, dispenser parameters, nozzle type, on / off timing, feed rate, bead thickness, bead width, bead location, or bead bonding strength. The feedback from a sensor may include for instance and without limitation, a characteristic of a workpiece such as a change in height, a rib, or a gap in portions needing a bead of material. The processor 111 outputs an adjustment to at least one of a robot path parameter 142 or a dispenser parameter 143. Optionally, the outputs are used to control a bead shape of a dispensed bead of material along a dispensing path.

[0067] The controller 110 further comprises a sensor controller 112. The sensor controller is configured to control operation of at least one sensor. The sensor controller 112 receives as inputs instructions from the processor 111 to perform a scan and outputs instructions to the sensor 121 to implement the instructions and perform the scan. As noted above, the verb to scan as used herein refers to traversing a point, a line, and / or an area, so may be a single image instead of output from a sweep of a scanner. As such, a scan can be one or more static images, a series of (e.g., height) maps, etc.

[0068] The controller 110 additionally comprises a robot motion controller 113. The robot motion controller 113 receives as inputs instructions from the processor 111 and in response controls an articulated arm of a robot according to the instructions. In some embodiments, the robot motion controller 113 controls the articulated arm of the robot to move a workpiece that is supported by the robot. In some embodiments, the robot motion controller 113 controls the articulated arm to move a dispenser 130 (e.g., that is attached to the robot). Optionally, two robots may be employed (e.g., a gantry system with multiple axes may be used to move both a workpiece and a dispenser). The controller 110 also comprises a dispenser controller 114. The dispenser controller 114 receives as inputs instructions from the processor 111 and in response controls a dispenser 130 to dispense a bead of material on a dispensing path.

[0069] The controller 110 further comprises a path planner unit 115. The path planner unit 115 receives as inputs at least one of workpiece characteristics 141, robot path parameters 142, dispenser parameters 143, process parameters 144, a nominal deposition toolpath 145, issue parameters 146, bead characteristics 147, a robot model 148, or a workpiece model 150. The path planner unit 115 outputs an adjusted deposition toolpath 151.

[0070] The controller 110 optionally also comprises a graphical user interface (GUI) generator 116, which may be configured to send information to a display 10. The GUI generator 116 may generate a graphical user interface for display on a display component 10 based on some or all of the information gathered or generated by the controller 110. Suitable displays include for instance and without limitation, a computer screen, a smart phone, or some other user device. Other units 117 may further be included in the controller 110. The controller 110 is described as having the functionality of receiving and sending communicable information to and from other devices. This may be done through an application program interface, for example, such that the controller 110 can receive and communicate with any units and / or models within each of the sensor system 120, the dispenser 130, and the data store 140.

[0071] The sensor system 120 comprises a sensor 121 that performs a scan of the workpiece and / or bead of material and outputs the scan to the path planner unit 115. Any suitable sensor may be employed that captures a scan, for instance and without limitation, a light detection and ranging (LIDAR) system, a laser profdometer, an area snapshot sensor, a triangulation-based sensor, a time-of-flight sensor, a laser point sensor, an optical coherence tomography sensor, a confocal sensor, a dynamic vision sensor, a red, blue, and green (RBG) camera, a red, blue, green, and depth (RBGD) camera, a black and white (B&W) camera, and / or a three-dimensional (3D) image sensor. Other units 122 may further be included in the sensor system 120.

[0072] The system 100 further comprises a dispenser 130. For example, the dispenser 130 may be a robotic adhesive dispensing unit with a robot arm having a dispenser attached thereto. In some cases, the dispenser 130 is attached to an alternate surface / object that is within a robotic workspace. For instance, one suitable dispenser is as described in detail in PCT Publication No. WO 2020 / 174394 (Napierala et al.), incorporated herein by reference in its entirety.

[0073] The system 100 optionally also comprises a robot 170. Some suitable robots and their uses are described further below.

[0074] The data store 140 is configured to communicate with the controller 110, the sensor system 120, and the dispenser 130. The data store 140 may be local to the controller 110 or may be accessible through a cloud-based network. Similarly, while the controller 110 is illustrated in FIG. 1 as local to the system 100, it is expressly contemplated that the controller 110 may be remote from the system 100 and may receive signals, and send commands, using a wireless or cloud-based network. The data store 140 optionally comprises a workpiece characteristics unit 141. The workpiece characteristics unit 141 contains information about properties of the workpiece, for instance at least one of the following: a change in height, a change in width, a wall, a rib, a seam, an edge, a change in a bonding strength need, a gap in portions needing a bead of material, or a portion where a head and a tail of the bead of material have a junction.

[0075] The data store 140 optionally comprises a robot path parameters unit 142. The robot path parameters unit 142 contains information about parameters for a robot path, for instance at least one of a tool velocity, a tool orientation, or tool position. It is noted that gap height (e.g., in the Z-axis) may be a specific case of a tool position (e.g., located in a particular position within each of the X-, Y-, and Z- axes).

[0076] The data store 140 optionally comprises a dispenser parameters unit 143. The dispenser parameters unit 143 contains information about parameters for the dispenser 130, for instance at least one of a feed rate, an on / off timing, a nozzle inner diameter, a nozzle outer diameter, a nozzle cross-sectional shape, or a deposition temperature.

[0077] The data store 140 optionally comprises a process parameters unit 144. The process parameters unit 144 contains information about parameters for a process, for instance at least one of a dispenser flow rate, a dispenser nozzle width, a tool velocity, a tool acceleration, a tool jerk, or a tool orientation.

[0078] The data store 140 comprises a nominal deposition toolpath unit 145. The nominal deposition toolpath unit 145 contains a predefined toolpath for depositing a bead of material. The toolpath is defined on a workpiece model 150, which may be a computer aided design (CAD) model, a depth image, a point cloud, or other model, which is also included in the data store 140 or otherwise retrievable.

[0079] The data store 140 optionally comprises an issue parameters unit 146. The issue parameters unit 146 contains information regarding potential issues for a toolpath, for instance a robotic collision, a singularity, a robot joint limit, a robot dynamic limit, a discontinuity in robot acceleration and velocity profile, a non-uniformity of deposited material, an undesirable tool configuration, or a workspace limit.

[0080] The data store 140 optionally comprises a bead characteristics unit 147. The bead characteristics unit 147 contains information about, for instance, one or more of bead height, bead width, a blend of one portion of a bead with a second portion of a bead, a cross-sectional shape of the bead, bead material chemical composition, state of matter, temperature, viscosity, bonding strength, color, etc. In some cases, the bead material has a melt viscosity of 100 Pascal-Seconds to 1000 Pascal-Seconds at 190°C and a shear rate of 10 sec'1, of 50 Pascal-Seconds to 500 Pascal-Seconds at 190°C and a shear rate of 100 sec'1, or 1 Pascal-Seconds to 100 Pascal-Seconds at 190°C and a shear rate of 1000 sec'1.

[0081] The data store 140 optionally comprises a robot model unit 148 that contains a digital model of at least a portion of the robot, for instance a robot arm and / or an end effector of the robot that is configured to dispense a bead of material (e.g., the dispenser). In some cases, the robot model unit 148 contains a digital model of the entire robot.

[0082] The data store 140 optionally comprises an information database unit 149 that contains any additional relevant information for access by any of the units in the data store 140 or in the controller 110. The data store 140 optionally comprises a workpiece model unit 150 that contains a digital model (e.g., a CAD model) of at least a portion of the workpiece (e.g., one or more surfaces on which a bead of material is to be deposited). In some cases, the workpiece model unit 150 contains a digital model of the entire workpiece.

[0083] The data store 140 comprises an adjusted deposition toolpath unit 151. The adjusted deposition toolpath unit 151 contains information regarding a deposition toolpath that has been created by optimizing a deposition path using at least one process parameter and at least one path or parameter tolerance. In some cases, an adjusted deposition toolpath is optimized for a robot having six degrees of freedom to implement a non-linear robotic trajectory of deposition of a bead material on a workpiece.

[0084] Other units 152 may further be included in the data store 140.

[0085] FIG. 2 illustrates an example system, in which some possible interactions between certain components are depicted. A workpiece 160 is depicted as interacting with each of a sensor 121, a dispenser 130, and a robot 170. The sensor 121 can interact with each of a sensor controller 112, a processor 111, the dispenser 130, and the workpiece 160. The sensor controller 112 can also interact with the processor 111. The dispenser 130 can interact with each of a dispenser controller 112, the sensor 121, the workpiece 160, and the robot 170. The dispenser controller 112 can also interact with the processor 111. The robot can also interact with a robot motion controller 113. The processor 111 is depicted as interacting with each of the sensor controller 112, the robot motion controller 113, the dispenser controller 112, the sensor 121, a workpiece model unit 150, a dispenser parameters unit 143, a process parameters unit 144, an issue parameters unit 146, a head characteristics unit 147, a nominal deposition toolpath unit 145, an adjusted deposition toolpath 151, a robot model unit 148, an information database unit 149, a workpiece characteristics unit 141, a robot path parameters unit 142, and a path planner unit 115.

[0086] In methods of controlling a bead shape of a dispensed bead of material along a dispensing path, the bead shape may be varied. The variation of the bead shape is not particularly limited and may include for instance any one or more of a variation in bead height, a variation in bead width, a blend of one portion of a bead with a second portion of a bead, a variation in cross-sectional shape of the bead, or a creation of a gap between adjacent sections of the bead in the dispensing path. Varying the bead shape may be executed using numerous different adjustments; for example, blending two portions of a bead may be achieved by one or more of varying a tool (e.g., dispenser) velocity along a blending path, increasing a dispensing distance along a blending path, and / or changing an overall blending distance on the workpiece. In certain embodiments, blending of two portions of a bead occurs at a junction of a head and a tail of the bead of material. The head is a first portion of bead material dispensed on the workpiece and the tail is an end portion of bead material, dispensed adjacent to the head.

[0087] Referring to FIGS. 3 A-3C, schematic diagrams depict an exemplary variation to a blending distance to blend two portions of a bead at a junction of a head and a tail of the bead of material, with a top view (FIG. 3 A) of a nominal dispense toolpath PnOminai, a closer top view (FIG. 3B) of a portion of the nominal dispense toolpath Pnominai with variations to the toolpath indicated in the diagram. In particular, the diagram in FIG. 3B shows extrapolating the ending portion Ptaii of the robot toolpath with an extra path (so-called “blending path”) that overlaps with the starting portion Phead of the robot toolpath, with the parameter of increasing the dispense distance and increasing the blending distance. Referring to FIG. 3C, a side view illustrates that as a result, the bead of material 310 on a workpiece substrate 340 has a blended junction of its head 320 and its tail 330. A dispenser nozzle 350 is shown, plus an arrow D indicating the direction the nozzle 350 traveled while dispensing.

[0088] Referring to FIGS. 3D-3I, photographs are provided of the effects of increasing blending distance. FIGS. 3D and 3E show a top view and a side view, respectively, of a head-tail junction 360 with no extra blending distance. It can be seen that the bead of material at the tail 330 has a smaller cross-section than the bead of material at the head 320 and there is a small air gap between the tail 330 and the workpiece substrate 340. As such, in some cases variation of a bead shape comprises a variation in cross-sectional shape of the bead. FIGS. 3F and 3G show a top view and a side view, respectively, of a head-tail junction 360 with 3 mm of extra blending distance. FIGS. 3D and 3E show a top view and a side view, respectively, of a head-tail junction 360 with 5 mm of extra blending distance. The extra blending distances of 3 mm and 5 mm result in closer cross-section size of the bead material at the tail 330 to that of the bead material at the head 320. Hence, by tuning the extra dispensing distance, a seamless junction may be formed for hermetic sealing applications while a junction with an air channel may be formed for ventilation-required applications.

[0089] Referring to FIGS. 4A-4B, schematic diagrams depict an exemplary variation to a gradient thickness to blend two portions of a bead at a junction of a head and a tail of the bead of material. In particular, the diagram of FIG. 4A shows that the head 420 of a bead of material 410 was dispensed such that the thickness of the bead gradually increased over a gradient distance G until reaching a constant full thickness. The diagram of FIG. 4B shows that the tail 430 of the bead of material 410 was dispensed such that the thickness of the bead gradually decreased over the gradient distance G to achieve the same full thickness due to the combined thicknesses of the head 420 and tail 430.

[0090] In some embodiments, a dispenser nozzle could be a “smear nozzle”, which is defined as a nozzle that smooths the bead immediately after dispensing. The outer diameter of a smear nozzle could be designed such that its outer diameter is larger than the maximum value of desired bead width along the dispense path. For instance, FIG. 5 provides a schematic diagram depicting the effect of decreasing velocity of deposition of a bead of material 510 on a workpiece substrate 540. As the velocity of deposition lowered from left to right in the figure, a larger smeared bead width W can be seen, which is controllable up to the width of an outer diameter OD of a dispenser nozzle 550. For instance, for a smear nozzle with an outer diameter of 20 mm, the maximum achievable bead width is equal to the diameter (i.e., 20 mm). Arrows D indicate the direction the nozzle 550 traveled while dispensing.

[0091] In certain embodiments, a method includes controlling on / off timing of a dispenser valve based on manual or automated selection of path locations and / or workpiece features. For example, FIG. 6A provides a schematic diagram depicting a workpiece 600 having four sections of workpiece substrate 640 that require the deposition of a bead of material 610 along four curved comers 602 of the workpiece 600. A sensor 670 (e.g., a laser profilometer) may be employed to detect each section of substrate 640 to inform the locations during which the dispenser valve 680 should be in an open position to be on and dispensing the bead of material 610 as well as the locations during which the dispenser valve 680 should be in a closed position to be off and not dispensing the material. In this particular example, a difference in the height of the workpiece 600 is determined by the sensor 670 to differentiate between the on and off states. FIG. 6B is a photograph of an actual bead of material 610 deposited on a workpiece substrate 640 having gaps (indicated by dotted lines) between adjacent sections due to the dispenser valve (not shown) being turned off along portions of the dispensing path. As such, in some cases variation of the bead shape comprises a creation of at least one gap between adjacent sections of the bead in the dispensing path. Similarly, deposition of a bead of material on a rib of a workpiece is described in detail below in Example 1.

[0092] Additional exemplary variables that may be manipulated to alter deposition of a bead of material include controlling one or more of material feed rate, robot tool velocity, tool orientation, or gap height based on user inputs and / or online sensor feedback. For instance, FIG. 7 provides a schematic diagram depicting a bottom view of the effects on a width of a bead of material 710 by changing a material feed rate F and / or a tool velocity V. Changing the bead width along a dispense path may be advantageous to achieve a variety of desired bonding strengths at different locations on a workpiece.

[0093] In some cases, it may be useful to control a bead thickness via material feed rate, robot tool velocity, tool orientation, and / or gap height to compensate for different bonding heights at different locations of a workpiece, such as depicted in FIGS. 8A-8B. Deposition variables may thus be selected to achieve deposition of specific thicknesses of bead material. Referring to FIG. 8 A, a series of sections of a bead of material 810 are deposited on a workpiece substrate 840 by a nozzle 850 in a direction D indicated by the arrow, with each section having a smaller thickness than the adjacent section to the right. Referring to FIG. 8B, the particular thicknesses were chosen to be complementary to heights of portions of a second workpiece substrate 842 attached to the (first) workpiece substrate 840 by the bead of material 810. FIG. 8C is a photograph of an actual bead of material 810 deposited on a workpiece substrate 840 using a varying gap height along a continuous dispense path for different bonding heights. A portion of the bead of material 810 was deposited using a gap height of 0 mm, while the thicker portion of the bead of material 810 was deposited using a gap height of 3 mm.

[0094] Another alternative deposition involves a constant bead width with a variable bead thickness via material feed rate, robot tool velocity, tool orientation, and / or gap height. Referring to FIG. 9A, a side view of a schematic diagram depicts a bead of material 910 deposited on a workpiece substrate 940 by a nozzle 950 in a direction D indicated by the arrow, with each section having a smaller thickness than the adjacent section to the right. FIG. 9B is a top view of the same bead of material 910 on the workpiece substrate 940, showing that the width remains constant regardless of the thickness.

[0095] Results of varying material feed rate and tool velocity to achieve variable bead width along a continuous path is shown in FIG. 10, which is a photograph of three actual beads of material 1010 deposited on a workpiece substrate 1040 using varying feed rate (top) or varying tool velocity (middle and botom). Graphs of the relative changes in feed rate or tool velocity are depicted next to each portion of the photograph.

[0096] Referring to FIG. 11, a photograph is provided showing how varying a feed rate can affect the width of a bead of material 1110. A transition distance DTbetween two bead width levels caused by a step change in feed rate can be measured by a caliper 1105.

[0097] As noted above, more than one type of robot configuration may be useful in implementing methods according to the present disclosure. Referring to FIGS. 12A-12B, schematic diagrams depict two different robot configurations. In FIG. 12A, a dispenser 1255 is mounted on a robot arm 1292 while a workpiece 1200 is placed on a workspace surface 1294. In FIG. 12B, a workpiece 1200 is mounted on a robot arm 1292 while a dispenser 1255 is mounted on a static frame structure 1296. In each figure, a sensor 1270 is also depicted.

[0098] In a second aspect, a method of optimizing a non-linear robotic trajectory of deposition of a bead material is provided. The method comprises: a) obtaining a nominal deposition path; b) selecting at least one process parameter; c) optimizing the deposition path using the at least one process parameter and at least one path or parameter tolerance to create an adjusted deposition path; d) checking for at least one issue along the adjusted deposition path; and e) finalizing the adjusted deposition path.

[0099] FIG. 13 is a flow chart of a method of optimizing a non-linear robotic trajectory of deposition of a bead material. The method includes the operation 1310 to Obtain a nominal deposition path; the operation 1320 to Select at least one process parameter; and the operation 1330 to Optimize the deposition path using the at least one process parameter and at least one path or parameter tolerance to create an adjusted deposition path. The method further includes the operation 1340 to Check for at least one issue along the adjusted deposition path and the operation 1350 to Finalize the adjusted deposition path. In certain cases, checking for issue(s) results in determining that there is an issue along the adjusted deposition path. At that point, the method typically further includes repeating operations b) through d) (e.g., operations 1320, 1330, and 1340) at least once prior to performing operation e) (e.g., operation 1350). In certain other cases, checking for issue(s) results in the operation 1360 to determine that the nominal deposition path cannot be sufficiently optimized without causing at least one issue along the adjusted deposition path. Some exemplary issues that may be discovered include for instance and without limitation, a robotic collision, a singularity, joint limits, dynamic limits, discontinuity in acceleration and velocity profile, non-uniformity of deposited material, undesirable tool configurations, or workspace limits. At that point, the method typically further includes requesting at least one of 1) a different nominal deposition path or 2) at least one different i) path or ii) parameter tolerance.

[0100] In certain embodiments, a nominal deposition path is not already available, thus sometimes it is necessary to create a nominal deposition path to begin the method. Suitable exemplary process parameters that may be selected include for instance and without limitation, a dispenser flow rate, a dispenser nozzle width, a tool velocity, a tool acceleration, a tool jerk, or a tool orientation.

[0101] In some cases, optimizing comprises analyzing a curvature of the nominal deposition path and adjusting at least one of a distance between adjacent path points, a time between adjacent path points, or a radius of the deposition path. Optionally, the adjusted deposition path is optimized for a robot having six degrees of freedom or seven degrees of freedom to implement the non-linear robotic trajectory of deposition of the bead material. For instance, a robot having seven DOF is commercially available from vendors such as KUKA (Augsburg, Germany), including the LBR iiwa robot and the LBR Med robot.

[0102] Preferably, at least a portion of the finalized adjusted deposition path comprises a larger radius of curvature than the nominal deposition path.

[0103] In a third aspect, a method of depositing a bead of material in a non-linear path is provided. The method comprises optimizing a non-linear robotic trajectory of deposition of ahead material according to any embodiment of the second aspect described in detail above; and depositing the bead of material in the finalized adjusted path. FIG. 14 is a flow chart of a method of depositing a bead of material in a nonlinear path. The method includes operation 1410 to Optimize a non-linear robotic trajectory of deposition of a bead material according to any embodiment of the method of optimizing a non-linear robotic trajectory of deposition of a bead material; and operation 1420 to Deposit the bead of material in the finalized adjusted path.

[0104] An offline-programing software can be used to design the robotic trajectory for the desired bead of material deposition. This designed path is then analyzed to determine curvature of the path and Cartesian dynamics (e.g., velocity, acceleration, and jerk) of the trajectory. The path is optionally also analyzed to determine joint dynamics of the trajectory (e.g., if a robot model is utilized). The path is then optimized to ensure that it is suitable for dispensing the bead of material in the most consistent matter. There are typically two different goals of the optimization - avoiding tight radii along the path and maintaining consistent velocity.

[0105] The first goal, avoiding tight radii, is achieved by adjusting any path points that exceed some curvature threshold. The curvature threshold is determined by the nozzle or end-effector tip characteristic width. For a dispensed bead of material, for example, this would be the width of the nozzle in the direction perpendicular to travel and perpendicular to the surface normal. This can be referred to as the y- direction, with x-direction being direction of travel, and z-direction being the surface normal direction, e.g., as depicted on a schematic diagram of a side view of a nozzle 1550 of a dispenser 1555 in FIG. 15. Once this characteristic width is determined, a velocity change along the robot tool center point (TCP) (i.e., where the material is dispensed) can be calculated. The velocity at a point along the y-direction is determined by this formula: Where R is the radius of the path, vnominalis the nominal velocity at the TCP, y is the position of the point along the y-direction, d is the distance from the current point to the next, and t is the time step to the next point in the path. Determining a ratio between the nominal velocity and the velocity at some y-offset position can be calculated with the following formula:

[0106] From this formula, it is apparent that if there is a large radius, or the radius approaches infinity - as happens in a straight line - this ratio approaches 1, or the velocities of any point offset in the y-direction is equal to the TCP velocity. It is also clear that a large step between points (d) or a large offset (y) can contribute substantially to a difference in the velocity ratio. In some cases, the velocity ratio can even be 0 or negative. In an ideal scenario, the velocity ratio would be within some tolerance ±5 around 1, indicating the following:

[0107] Because of hardware constraints and cycle-time constraints, there is generally little control over the maximum width (y) (e.g., ”y„„„" in FIG. 15) and the nominal velocity, leaving only the distance between points (t), time between points (t), and radius (R) for adjustment. A path programmed using an offline programming software will generally create a path with consistent point discretization, so the d and t levers may not be particularly useful in ensuring the velocity ratio lands within the bounds. In such cases the path curvature is the more important variable to optimize.

[0108] To increase the radius, or reduce the curvature, the angle between the line connecting the current point to the previous point and the line connecting the current point to the next point is calculated. If the angle is less than some value <p, the point is moved along the radial axis (i.e., the axis pointing from the current point to the center of the circle creating the radius or curvature arc) by some distance A. FIGS. 16-17 depict some exemplary adjustments to a path. This is done for each point along the path, moving forward through time, then backward until all points give a velocity ratio within the given tolerances. This will create a path that is consistent in velocity up to the given tolerance at each point across the width of the end-effector, applicator, or dispenser. To see the effects of this, graphs are given in FIGS. 18-19. FIG. 18 shows how adjusting the tolerance value (5) will affect the final path and FIG. 19 shows how varying the applicator width (y) will affect the final path.

[0109] The next portion of the optimization typically involve looking at the dynamics of the new robotic trajectory, optimized for the velocity ratio. In general, the nominal velocity should stay constant throughout a material deposition path. If it does not, this needs to be accounted for. This can happen either by altering the trajectory further by other means (such as changing dynamic constraints - velocity, acceleration, jerk, etc.) or by matching the material deposition rate with the variable nominal velocity. Altering the trajectory by changing dynamic constraints generally depends on cycle-times, robot constraints, and other parameters that may or may not be in one’s control. If it is not possible to change those values, a model of the material deposition may be utilized, then matching it to the required nominal velocity. In general, a material deposition rate or flowrate can be written as a formula:

[0110] Q(jj, t) = Av

[0111] In words, this means the material deposition rate is a function of time and some group of variables, ??, that are specific to the hardware being used. For example, a pressure based extruder might use pneumatic pressure to force a material out of a nozzle, and the variables of interest would be the pressure. A is the cross-sectional area at the deposition point (nozzle) and v is the nominal velocity. If the nominal velocity is changing over time, and the hardware can change deposition rate with a fast-enough response time (what is fast-enough depends on the application, nominal velocity, and hardware being used), then the offline programming software can optimize its offline deposition trajectory to follow to match the nominal velocity trajectory, thus maintaining the correct ratio of deposition rate to tool velocity, rather than assuming a constant deposition rate at each time step during the trajectory. This can be seen in FIG. 20. Some deposition parameters (perhaps pressure, like in the example given) are varied as nominal velocity varies to maintain a consistent deposition rate.

[0112] With these two steps, it is possible to move toward a consistent deposited material cross-section at each point along the trajectory. Additional steps can be taken to ensure that the altered path points from adjusting the curvature have not caused issues to the process, such as robotic collisions, singularities, or other undesirable effects, before the path is executed. If the process cannot be altered sufficiently without introducing these effects, the user will be notified, and can either adjust the acceptable tolerances, or create a new path. The software could also run this process iteratively, providing adjustments to tolerances or path variations and the provide them to the user.

[0113] FIG. 21 illustrates a dispensing system architecture. Architecture 2100 illustrates one embodiment of an implementation of a dispensing system 2110. As an example, architecture 2100 can provide computation, software, data access, and storage services that do not require end-user knowledge of the physical location or configuration of the system that delivers the services. In various embodiments, remote servers can deliver the services over a wide area network, such as the internet, using appropriate protocols. For instance, remote servers can deliver applications over a wide area network and they can be accessed through a web browser or any other computing component. Software or components shown or described in FIGS. 1-20 as well as the corresponding data, can be stored on servers at a remote location. The computing resources in a remote server environment can be consolidated at a remote data center location or they can be dispersed. Remote server infrastructures can deliver services through shared data centers, even though they appear as a single point of access for the user. Thus, the components and functions described herein can be provided from a remote server at a remote location using a remote server architecture. Alternatively, they can be provided by a conventional server, installed on client devices directly, or in other ways.

[0114] In the example shown in FIG. 21, some items are similar to those shown in earlier figures. FIG. 21 specifically shows that a controller 2110 can be located at a remote server location 2102. Therefore, a computing device 2120 accesses the controller 2110 through the remote server location 2102. A user 2150 can use the computing device 2120 to access user interfaces 2122 as well. For example, a user 2150 may be a user wanting to check on the progress of modification of a workpiece while sitting in a parking lot, and interacting with an application on the user interface 2122 of their smartphone 2120, or laptop 2120, or other computing device 2120, e.g., an augmented reality (AR) device such as AR glasses.

[0115] FIG. 21 shows that it is also contemplated that some elements of systems described herein are disposed at a remote server location 2102 while others are not. By way of example, each of a data store 2130, sensor system 2160, and the dispenser 2170 can be disposed at a location separate from the location 2102 and accessed through the remote server at location 2102. Regardless of where it is located, the data store 2130 can be accessed directly by a computing device 2120, through a network (either a wide area network or a local area network), hosted at a remote site by a service, provided as a service, or accessed by a connection service that resides in a remote location. Also, the data can be stored in substantially any location and intermittently accessed by, or forwarded to, interested parties. For instance, physical carriers can be used instead of, or in addition to, electromagnetic wave carriers. This may allow a user 2150 to interact with the controller 2110 through their computing device 2120.

[0116] It will also be noted that the elements of systems described herein, or portions of them, can be disposed on a wide variety of different devices. Some of those devices include servers, desktop computers, laptop computers, imbedded computer, industrial controllers, tablet computers, or other mobile devices, such as palm top computers, cell phones, smart phones, multimedia players, personal digital assistants, etc.

[0117] FIGS. 22-24 illustrate example devices that can be used in the embodiments shown in previous Figures. FIG. 22 illustrates an example mobile device that can be used in the embodiments shown in previous Figures. FIG. 22 is a simplified block diagram of one illustrative example of a handheld or mobile computing device that can be used as either a worker’s device or a supervisor / safety officer device, for example, in which the present system (or parts of it) can be deployed. For instance, a mobile device can be deployed in the operator compartment of computing device for use in generating, processing, or displaying the data.

[0118] FIG. 22 provides a general block diagram of the components of a mobile cellular device 2216 that can mn some components shown and described herein. The mobile cellular device 2216 interacts with them or runs some and interacts with some. In the device 2216, a communications link 2213 is provided that allows the handheld device to communicate with other computing devices and under some embodiments provides a channel for receiving information automatically, such as by scanning. Examples of communications link 2213 include allowing communication though one or more communication protocols, such as wireless services used to provide cellular access to a network, as well as protocols that provide local wireless connections to networks.

[0119] In other examples, applications can be received on a removable Secure Digital (SD) card that is connected to an interface 2215. The interface 2215 and communication links 2213 communicate with a processor 2217 (which can also embody a processor) along a bus 2219 that is also connected to a memory 2221 and input / output (I / O) components 2223, as well as clock 2225 and location system 2227.

[0120] I / O components 2223, in one embodiment, are provided to facilitate input and output operations and the device 2216 can include input components such as buttons, touch sensors, optical sensors, microphones, touch screens, proximity sensors, accelerometers, orientation sensors and output components such as a display device, a speaker, and or a printer port. Other I / O components 2223 can be used as well.

[0121] The clock 2225 illustratively comprises a real time clock component that outputs a time and ate. It can also provide timing functions for the processor 2217.

[0122] Illustratively, the location system 2227 includes a component that outputs a current geographical location of the device 2216. This can include, for instance, a global positioning system (GPS) receiver, a LORAN system, a dead reckoning system, a cellular triangulation system, or other positioning system. It can also include, for example, mapping software or navigation software that generates desired maps, navigation routes and other geographic functions.

[0123] A memory 2221 stores operating system 2229, network settings 2231, applications 2233, application configuration settings 2235, data store 2237, communication drivers 2239, and communication configuration settings 2241. The memory 2221 can include all types of tangible volatile and non-volatile computer-readable memory devices, ft can also include computer storage media (described below). Memory 2221 stores computer readable instructions that, when executed by the processor 2217, cause the processor to perform computer-implemented steps or functions according to the instructions. Processor 2217 can be activated by other components to facilitate their functionality as well, ft is expressly contemplated that, while a physical memory store 2221 is illustrated as part of a device, that cloud computing options, where some data and / or processing is done using a remote service, are available.

[0124] FIG. 23 shows that the device can also be a smart phone 2371. The smart phone 2371 has a touch sensitive display 2373 that displays icons or tiles or other user input mechanisms 2375. Mechanisms 2375 can be used by a user to run applications, make calls, perform data transfer operations, etc. In general, the smart phone 2371 is built on a mobile operating system and offers more advanced computing capability and connectivity than a feature phone. Note that other forms of the devices are possible. However, while FIG. 23 illustrates an embodiment where a device 2300 is a smart phone 2371, it is expressly contemplated that a display may be presented on another comping device.

[0125] FIG. 24 is one example of a computing environment in which elements of systems and methods described herein, or parts of them (for example), can be deployed. With reference to FIG. 24, an example system for implementing some embodiments includes a general-purpose computing device in the form of a computer 2410. Components of the computer 2410 may include, but are not limited to, a processing unit 2420 (which can comprise a processor), a system memory 2430, and a system bus 2421 that couples various system components including the system memory to the processing unit 2420. The system bus 2421 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. Memory and programs described with respect to systems and methods described herein can be deployed in corresponding portions of FIG. 24.

[0126] The computer 2410 typically includes a variety of computer readable media. Computer readable media can be any available media that can be accessed by the computer 2410 and includes both volatile / nonvolatile media and removable / non-removable media. By way of example, and not limitation, computer readable media may comprise computer storage media and communication media. Computer storage media is different from, and does not include, a modulated data signal or carrier wave. It includes hardware storage media including both volatile / nonvolatile and removable / non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by the computer 2410. Communication media may embody computer readable instructions, data structures, program modules or other data in a transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal.

[0127] The system memory 2430 includes computer storage media in the form of volatile and / or nonvolatile memory such as read only memory (ROM) 2431 and random-access memory (RAM) 2432. A basic input / output system 2433 (BIOS) containing the basic routines that help to transfer information between elements within the computer 2410, such as during start-up, is typically stored in ROM 2431. RAM 2432 typically contains data and / or program modules that are immediately accessible to and / or presently being operated on by processing unit 2420. By way of example, and not limitation, FIG. 24 illustrates an operating system 2434, application programs 2435, other program modules 2436, and program data 2437.

[0128] The computer 2410 may also include other removable / non-removable and volatile / nonvolatile computer storage media. By way of example only, FIG. 24 illustrates a hard disk drive 2441 that reads from or writes to non-removable, nonvolatile magnetic media, nonvolatile magnetic disk 2452, an optical disk drive 2455, and nonvolatile optical disk 2456. The hard disk drive 2441 is typically connected to the system bus 2421 through a non-removable memory interface such as interface 2440, and optical disk drive 2455 is typically connected to the system bus 2421 by a removable memory interface, such as interface 2450.

[0129] Alternatively, or in addition, the functionality described herein can be performed, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-programmable Gate Arrays (FPGAs), Application-specific Integrated Circuits (e.g., ASICs), Application-specific Standard Products (e.g., ASSPs), System-on-a-chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), etc. The drives and their associated computer storage media discussed above and illustrated in FIG. 24, provide storage of computer readable instructions, data structures, program modules and other data for the computer 2410. In FIG. 24, for example, a hard disk drive 2441 is illustrated as storing operating system 2444, application programs 2445, other program modules 2446, and program data 2447. Note that these components can either be the same as or different from operating system 2434, application programs 2435, other program modules 2436, and program data 2437.

[0130] A user may enter commands and information into the computer 2410 through input devices such as a keyboard 2462, a microphone 2463, and a pointing device 2461, such as a mouse, trackball or touch pad. Other input devices (not shown) may include a joystick, game pad, satellite receiver, scanner, or the like. These and other input devices are often connected to the processing unit 2420 through a user input interface 2460 that is coupled to the system bus but may be connected by other interface and bus stmctures. A visual display 2491 or other type of display device is also connected to the system bus 2421 via an interface, such as a video interface 2490. In addition to the monitor, computers may also include other peripheral output devices such as speakers 2497 and printer 2496, which may be connected through an output peripheral interface 2495.

[0131] The computer 2410 is operated in a networked environment using logical connections, such as a Local Area Network (LAN) or Wide Area Network (WAN) to one or more remote computers, such as a remote computer 2480.

[0132] When used in a LAN networking environment, the computer 2410 is connected to the LAN 2471 through a network interface or adapter 2470. When used in a WAN networking environment, the computer 2410 typically includes a modem 2472 or other means for establishing communications over the WAN 2473, such as the Internet. In a networked environment, program modules may be stored in a remote memory storage device. FIG. 24 illustrates, for example, that remote application programs 2485 can reside on a remote computer 2480.

[0133] In the present detailed description of the preferred embodiments, reference is made to the accompanying drawings, which illustrate specific embodiments in which the invention may be practiced. The illustrated embodiments are not intended to be exhaustive of all embodiments according to the invention. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

[0134] Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein.

[0135] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” encompass embodiments having plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including "and / or" unless the content clearly dictates otherwise.

[0136] As used herein, when an element, component, or layer for example is described as forming a “coincident interface” with, or being “on,” “connected to,” “coupled with,” “stacked on” or “in contact with” another element, component, or layer, it can be directly on, directly connected to, directly coupled with, directly stacked on, in direct contact with, or intervening elements, components or layers may be on, connected, coupled or in contact with the particular element, component, or layer, for example. When an element, component, or layer for example is referred to as being “directly on,” “directly connected to,” “directly coupled with,” or “directly in contact with” another element, there are no intervening elements, components or layers for example. The techniques of this disclosure may be implemented in a wide variety of computer devices, such as servers, laptop computers, desktop computers, notebook computers, tablet computers, hand-held computers, smart phones, and the like. Any components, modules or units have been described to emphasize functional aspects and do not necessarily require realization by different hardware units. The techniques described herein may also be implemented in hardware, software, firmware, or any combination thereof. Any features described as modules, units or components may be implemented together in an integrated logic device or separately as discrete but interoperable logic devices. In some cases, various features may be implemented as an integrated circuit device, such as an integrated circuit chip or chipset. Additionally, although a number of distinct modules have been described throughout this description, many of which perform unique functions, all the functions of all of the modules may be combined into a single module, or even split into further additional modules. The modules described herein are only exemplary and have been described as such for better ease of understanding.

[0137] If implemented in software, the techniques may be realized at least in part by a computer- readable medium comprising instructions that, when executed in a processor, performs one or more of the methods described above. The computer-readable medium may comprise a tangible computer-readable storage medium and may form part of a computer program product, which may include packaging materials. The computer-readable storage medium may comprise random access memory (RAM) such as synchronous dynamic random access memory (SDRAM), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), FLASH memory, magnetic or optical data storage media, and the like. The computer-readable storage medium may also comprise a non-volatile storage device, such as a hard-disk, magnetic tape, a compact disk (CD), digital versatile disk (DVD), Blu-ray disk, holographic data storage media, or other nonvolatile storage device.

[0138] The term “processor,” as used herein may refer to any of the foregoing structure or any other structure suitable for implementation of the techniques described herein. In addition, in some aspects, the functionality described herein may be provided within dedicated software modules or hardware modules configured for performing the techniques of this disclosure. Even if implemented in software, the techniques may use hardware such as a processor to execute the software, and a memory to store the software. In any such cases, the computers described herein may define a specific machine that is capable of executing the specific functions described herein. Also, the techniques could be fully implemented in one or more circuits or logic elements, which could also be considered a processor.

[0139] EXEMPLARY EMBODIMENTS

[0140] In a first embodiment, the present disclosure provides a method of controlling a bead shape of a dispensed bead of material along a dispensing path. The method comprises adjusting at least one of a) a robot path parameter or b) a dispenser parameter, using at least one of i) a user input or ii) a feedback from a sensor, to vary the bead shape of the dispensed bead of material based on a characteristic of the workpiece.

[0141] In a second embodiment, the present disclosure provides a method according to the first embodiment, wherein the characteristic of the workpiece comprises at least one of the following: a change in height, a change in width, a wall, a rib, a seam, an edge, a change in a bonding strength need, a gap in portions needing a bead of material, or a portion where a head and a tail of the bead of material have a junction.

[0142] In a third embodiment, the present disclosure provides a method according to the first embodiment or the second embodiment, wherein the characteristic of the workpiece comprises a change in height.

[0143] In a fourth embodiment, the present disclosure provides a method according to any of the first through third embodiments, wherein the characteristic of the workpiece comprises a change in width.

[0144] In a fifth embodiment, the present disclosure provides a method according to any of the first through third embodiments, wherein the characteristic of the workpiece comprises a wall.

[0145] In a sixth embodiment, the present disclosure provides a method according to any of the first through fifth embodiments, wherein the characteristic of the workpiece comprises a rib.

[0146] In a seventh embodiment, the present disclosure provides a method according to any of the first through sixth embodiments, wherein the characteristic of the workpiece comprises a seam.

[0147] In an eighth embodiment, the present disclosure provides a method according to any of the first through seventh embodiments, wherein the characteristic of the workpiece comprises an edge.

[0148] In a ninth embodiment, the present disclosure provides a method according to any of the first through eighth embodiments, wherein the characteristic of the workpiece comprises a change in a bonding strength need.

[0149] In a tenth embodiment, the present disclosure provides a method according to any of the first through ninth embodiments, wherein the characteristic of the workpiece comprises a gap in portions needing a bead of material.

[0150] In an eleventh embodiment, the present disclosure provides a method according to any of the first through tenth embodiments, wherein the characteristic of the workpiece comprises a portion where a head and a tail of the bead of material have a junction. In a twelfth embodiment, the present disclosure provides a method according to any of the first through eleventh embodiments, wherein the variation of the bead shape comprises at least one of the following: a variation in bead height, a variation in bead width, a blend of one portion of a bead with a second portion of a bead, a variation in cross-sectional shape of the bead, or a creation of a gap between adjacent sections of the bead in the dispensing path.

[0151] In a thirteenth embodiment, the present disclosure provides a method according to any of the first through twelfth embodiments, wherein the variation of the bead shape comprises a variation in bead height.

[0152] In a fourteenth embodiment, the present disclosure provides a method according to any of the first through thirteenth embodiments, wherein the variation of the bead shape comprises a variation in bead width.

[0153] In a fifteenth embodiment, the present disclosure provides a method according to any of the first through fourteenth embodiments, wherein the variation of the bead shape comprises a blend of one portion of a bead with a second portion of a bead.

[0154] In a sixteenth embodiment, the present disclosure provides a method according to the fifteenth embodiment, wherein the blend is at a junction of a head and a tail of the bead of material.

[0155] In a seventeenth embodiment, the present disclosure provides a method according to any of the first through sixteenth embodiments, wherein the variation of the bead shape comprises a variation in cross-sectional shape of the bead.

[0156] In an eighteenth embodiment, the present disclosure provides a method according to any of the first through seventeenth embodiments, wherein the variation of the bead shape comprises a creation of at least one gap between adjacent sections of the bead in the dispensing path.

[0157] In a nineteenth embodiment, the present disclosure provides a method according to the eighteenth embodiment, wherein the adjacent sections of the bead in the dispensing path comprise a junction of the head and the tail of the bead of material.

[0158] In a twentieth embodiment, the present disclosure provides a method according to any of the first through nineteenth embodiments, wherein the adjusting comprises a robot path parameter comprising at least one of a tool velocity, a tool orientation, or tool position.

[0159] In a twenty -first embodiment, the present disclosure provides a method according to any of the first through twentieth embodiments, wherein the adjusting comprises a robot path parameter comprising a tool velocity.

[0160] In a twenty-second embodiment, the present disclosure provides a method according to any of the first through twenty -first embodiments, wherein the adjusting comprises a robot path parameter comprising a tool orientation.

[0161] In a twenty -third embodiment, the present disclosure provides a method according to any of the first through twenty-second embodiments, wherein the adjusting comprises a robot path parameter comprising a tool position. In a twenty -fourth embodiment, the present disclosure provides a method according to any of the first through twenty -third embodiments, wherein the adjusting comprises a dispenser parameter comprising at least one of a feed rate, an on / off timing, a nozzle inner diameter, a nozzle outer diameter, or a nozzle cross-sectional shape.

[0162] In a twenty -fifth embodiment, the present disclosure provides a method according to any of the first through twenty -fourth embodiments, wherein the adjusting comprises a dispenser parameter comprising a feed rate.

[0163] In a twenty-sixth embodiment, the present disclosure provides a method according to any of the first through twenty -fifth embodiments, wherein the adjusting comprises a dispenser parameter comprising an on / off timing.

[0164] In a twenty-seventh embodiment, the present disclosure provides a method according to any of the first through twenty-sixth embodiments, wherein the adjusting comprises a dispenser parameter comprising a nozzle inner diameter.

[0165] In a twenty-eighth embodiment, the present disclosure provides a method according to any of the first through twenty-seventh embodiments, wherein the adjusting comprises a dispenser parameter comprising a nozzle outer diameter.

[0166] In a twenty -ninth embodiment, the present disclosure provides a method according to any of the first through twenty-eighth embodiments, wherein the adjusting comprises a dispenser parameter comprising a nozzle cross-sectional shape.

[0167] In a thirtieth embodiment, the present disclosure provides a method according to any of the first through twenty -ninth embodiments, wherein the dispenser is attached to a robot.

[0168] In a thirty -first embodiment, the present disclosure provides a method according to any of the first through thirtieth embodiments, wherein the workpiece is supported by a robot.

[0169] In a thirty-second embodiment, the present disclosure provides a method according to any of the first through thirty -first embodiments, wherein the adjusting is based at least in part on the feedback from a sensor selected from the group consisting of a light detection and ranging (LIDAR) system; a laser profilometer; an area snapshot sensor; a triangulation-based sensor; a time-of-flight sensor; a laser point sensor; an optical coherence tomography sensor; a confocal sensor; a dynamic vision sensor; a red, blue, and green (RBG) camera; a red, blue, green, and depth (RBGD) camera; a black and white (B&W) camera; and a three-dimensional (3D) image sensor.

[0170] In a thirty -third embodiment, the present disclosure provides a method according to any of the first through thirty-second embodiments, wherein the adjusting is based at least in part on the user input selected from the group consisting of tool position, tool velocity, tool orientation, dispenser parameters, nozzle type, on / off timing, feed rate, bead thickness, bead width, bead location, or bead bonding strength.

[0171] In a thirty -fourth embodiment, the present disclosure provides a method according to any of the first through thirty -third embodiments, wherein the material has a melt viscosity of 100 Pascal-Seconds to 1000 Pascal-Seconds at 190°C and a shear rate of 10 sec'1, of 50 Pascal-Seconds to 500 Pascal-Seconds at 190°C and a shear rate of 100 sec'1, or 1 Pascal-Seconds to 100 Pascal-Seconds at 190°C and a shear rate of 1000 sec'1.

[0172] In a thirty -fifth embodiment, the present disclosure provides a method of optimizing a non-linear robotic trajectory of deposition of a bead material. The method comprises a) obtaining a nominal deposition path; b) selecting at least one process parameter; and c) optimizing the deposition path using the at least one process parameter and at least one path or parameter tolerance to create an adjusted deposition path. The method further comprises d) checking for at least one issue along the adjusted deposition path; and e) finalizing the adjusted deposition path.

[0173] In a thirty-sixth embodiment, the present disclosure provides a method according to the thirty- fifth embodiment, further comprising determining that there is an issue along the adjusted deposition path and repeating operations b) through d) at least once prior to performing operation e).

[0174] In a thirty-seventh embodiment, the present disclosure provides a method according to the thirty- fifth embodiment or the thirty-sixth embodiment, wherein the issue comprises at least one of a robotic collision, a singularity, joint limits, dynamic limits, discontinuity in acceleration and velocity profile, non-uniformity of deposited material, undesirable tool configurations, or workspace limits.

[0175] In a thirty -eighth embodiment, the present disclosure provides a method according to the thirtysixth embodiment or the thirty-seventh embodiment, further comprising determining that the nominal deposition path cannot be sufficiently optimized without causing at least one issue along the adjusted deposition path and requesting at least one of 1) a different nominal deposition path or 2) at least one different i) path or ii) parameter tolerance.

[0176] In a thirty -ninth embodiment, the present disclosure provides a method according to any of the thirty -fifth through thirty -eighth embodiments, wherein the at least one process parameter comprises a dispenser flow rate, a dispenser nozzle width, a tool velocity, a tool acceleration, a tool jerk, or a tool orientation.

[0177] In a fortieth embodiment, the present disclosure provides a method according to any of the thirty- fifth through thirty -ninth embodiments, wherein the optimizing comprises analyzing a curvature of the nominal deposition path and adjusting at least one of a distance between adjacent path points, a time between adjacent path points, or a radius of the deposition path.

[0178] In a forty -first embodiment, the present disclosure provides a method according to any of the thirty -fifth through fortieth embodiments, wherein at least a portion of the finalized adjusted deposition path comprises a larger radius of curvature than the nominal deposition path.

[0179] In a forty-second embodiment, the present disclosure provides a method according to any of the thirty-fifth through forty -first embodiments, wherein the obtaining comprises creating a nominal deposition path.

[0180] In a forty -third embodiment, the present disclosure provides a method according to any of the thirty -fifth through forty-second embodiments, wherein the adjusted deposition path is optimized for a robot having six degrees of freedom to implement the non-linear robotic trajectory of deposition of the bead material. In a forty -fourth embodiment, the present disclosure provides a method of depositing a bead of material in a non-linear path. The method comprises optimizing a non-linear robotic trajectory of deposition of a bead material according to any of the thirty -fifth through forty -third embodiments; and depositing the bead of material in the finalized adjusted path.

[0181] EXAMPLES

[0182] These examples are offered to further illustrate the various specific and preferred embodiments and techniques. It should be understood, however, that many variations and modifications may be made while remaining within the scope of the present disclosure.

[0183] Experiments were conducted on a system including a robot holding a substrate / workpiece (see, e.g., FIG. 12B). The model of robot arms used was UR10 from Universal Robots USA, Inc. (Novi, MI). In the configuration of FIG. 12B, a Nordson “PROBOND” dispenser from Nordson (Westlake, OH) was mounted on a static frame stmcture. The dispenser was used to dispense a hot melt adhesive, which was “3M VHB” Extrudable Tape from 3M Company (St. Paul, MN), on a workpiece.

[0184] The controller program was implemented in Python 3 that runs on a PC with a Linux operation system. This PC-based controller was connected to the UR10 controller via a TCP / IP over ethemet cable. Actions of streaming robot motion command and reading current robot pose were communicated via a Real-Time Data Exchange (RTDE) interface at a frequency of 125 Hz maximum. The PC-based controller was also connected to sensors (e.g., laser profilometers: scanControl 2510-100 / BL, fromMicro- Epsilon (Raleigh, NC)) to scan a workpiece and to scan a deposited bead) via UDP over ethemet cables. 2D laser profiles were streamed at a frequency up to 4kHz from the sensors to a scan data buffer on the PC-based controller using scanCONTROL SDK from Micro-Epsilon (Raleigh, NC).

[0185] Within the UR10 robot controller, each target waypoint in Cartesian space was transformed to joint positions via an inverse kinematic model of the robot, which was then fed to a proportional feedback controller for motion control. The actual joint positions from the encoders were fed back to the RTDE interface after being transformed to a tool center pose (TCP) via a forward kinematic model of the robot.

[0186] Within the PC-based controller, a nominal path defining desired bead locations on a workpiece / part was first generated using a proprietary path planner, which includes part registration methods and a CAD-to-path process. The user-defined nominal path was then discretized into sequences of waypoints for robot execution. At each computation step (with a cycle time of 10-20 milliseconds) during a closed-loop dispensing process, a current robot TCP was first read from the robot controller. Next, the most recent sensor data (i.e., laser profiles from the scan data buffer of both laser profilometers) were transformed to the robot TCP coordinate system, which were used to determine an adjustment for a waypoint pose, and velocity, or dispenser feed rate (these adjustable parameters were selected by the user). Finally, the updated waypoints were added to the toolpath buffer for future execution by the UR10 motion controller.

[0187] A method for generating an adjusted deposition toolpath is as follows: 1. User defines a sequence of waypoints which define the robot trajectory. Each waypoint includes the information of a target robot pose, a blending radius, a target robot velocity, and dispensing parameters (e.g., feed rate percentage).

[0188] 2. User defines a time interval At for sending robot and dispenser commands to the controller.

[0189] 3. The path planner takes the user defined waypoints and At as inputs and outputs time series commands for the robot and the dispenser controller (e.g., a robot pose and a material feed rate percentage at each time step).

[0190] 4. In step 3, the path planner may perform a path re-parameterization step by a. Interpolating additional waypoints between user specified waypoints; b. Removing user specified waypoints if the travel time between certain waypoints is less than At; and c. Adjusting target robot velocity / robot pose to satisfy robot dynamic constraints (e.g., acceleration or jerk limit).

[0191] Example 1 : Rib detection using sensor feedback

[0192] On various parts (e.g., automotive parts such as spoiler assemblies), rib features having a small elevation from the part surface are presented as markers that indicate locations for (e.g., adhesive) bead deposition. The ability to track these rib features can, for instance, enable precise and repeatable deposition of adhesives on desired locations for optimal bonding performance.

[0193] One suitable method to adjust waypoint locations along the nominal path based on rib locations is depicted in FIG. 25. First, the nominal path 2510 defined in the robot base coordinate system and the scan profde 2520 defined in the scanner coordinate are all transferred to the TCP coordinate. Second, the intersection of the nominal path 2510 with the laser projection plane 2530 is computed by finding the first waypoint on the nominal toolpath that is behind the laser projection plane, denoted by Pj. This will be the waypoint to be updated based on the actual rib locations. Third, a rib peak is detected, and the peak location with an offset for desired bead thickness / gap height becomes the position of the adjusted waypoint, denoted by Pj. The time stamp from Pj is then assigned to Pj. A sequence of the adjusted waypoint p; forms the actual toolpath 2540 that is conformal to the part surface and also follows the peak of the rib. This detection method was tested on a curvilinear surface with rib features.

[0194] Referring to FIG. 26, a piece of paper was used as a workpiece substrate 2640, in which the paper was folded to form a rib 2644 extending from a first edge 2641 of the workpiece substrate 2640 to an opposing second edge 2643 of the workpiece substrate 2640. The rib detection was performed as described above using a UR10 robot, a Micro Epsilon scanCONTROL 2510-BL from Micro-Epsilon (Raleigh, NC), and the PC-based controller and controller program described above.

[0195] FIGS. 27A-C show plots of both the nominal deposition path 2701 and the planned deposition path 2703, over time, in each of the x-axis (FIG. 27A), y-axis (FIG. 27B), and z-axis (FIG. 27C). FIG. 27D is a map of the scanned surface of the workpiece substrate 2740 from the Micro Epsilon scanCONTROL 2510-BL.

[0196] A bead of “3M VHB” Extrudable Tape was applied using a Nordson “PROBOND” dispenser and a tapered nozzle having an inner diameter of 3 millimeters (mm), with a dispensing temperature of 400 degrees Fahrenheit and a constant feed rate of 5%. The nozzle 2850 is shown in FIG. 28A having a tapered end 2851 and in the process of dispensing a bead 2810. Referring to FIG. 28B, the bead of material 2810 can be seen applied to the rib 2844 on the workpiece substrate 2840 according to the planned deposition toolpath, starting near the first edge 2841 of the workpiece substrate 2840 and ending near the second edge 2843 of the workpiece substrate 2840. As can be seen in the figure, the deposition of the bead 2810 matches the actual location of the rib 2844 on the workpiece substrate 2840.

[0197] Example 2 - Bead width compensation with gap height sensing

[0198] Two experiments were performed to achieve deposition of a bead on a workpiece having a step change in height. In each, referring to FIG. 29A, a smear nozzle 2950 was used to deposit a bead of “3M VHB” Extrudable Tape from a Nordson “PROBOND” dispenser. The smear nozzle 2950 had an outer diameter (OD) of 20 mm and an inner diameter (ID) of 4 mm. Detection of a height of the workpiece substrate surface was performed as described above using a UR10 robot, a Micro Epsilon scanCONTROL 2510-BL from Micro-Epsilon (Raleigh, NC), and the PC-based controller and controller program described above. FIG. 29B provides a perspective view of the workpiece substrate 2940 having a height change 2945 from a first area 2947 to a second area 2949.

[0199] FIG. 29C is a map of the scanned surface of the workpiece substrate 2940 from the Micro Epsilon scanCONTROL 2510-BL.

[0200] In the first experiment, a tool speed was varied between 18 millimeters per second (mm / s) and 40 mm / s, while a feed rate was kept constant at 5%. FIGS. 29D-F show plots of the planned deposition path 2903, over time, in each of the x-axis (FIG. 29D), y-axis (FIG. 29E), and z-axis (FIG. 29F), and FIG. 29G shows the planned velocity 2905 over time to adapt to the height change. Referring to FIGS. 29H-I, photographs are provided of the final result of the smear nozzle depositing a bead 2910 deposited according to the planned deposition toolpath and velocity, starting at a first edge 2941 in the first area 2947 and ending at a second edge 2943 in the second area 2949. A top view is provided in FIG. 29H, and a side view is provided in 291.

[0201] In the second experiment, a tool speed was kept constant at 20 mm / s while a feed rate was kept constant at 10% in the first area 2947 of the workpiece substrate 2940 and 5% in the second area 2949 of the workpiece substrate 2940. FIGS. 29J-L show plots of the planned deposition path 2903, over time, in each of the x-axis (FIG. 29J), y-axis (FIG. 29K), and z-axis (FIG. 29L), and FIG. 29M shows the planned velocity 2905 over time to adapt to the height change. Referring to FIGS. 29N-O, photographs are provided of the final result of the smear nozzle depositing a bead 2910 deposited according to the planned deposition toolpath and velocity, starting at a first edge 2941 in the first area 2947 and ending at a second edge 2943 in the second area 2949. A top view is provided in FIG. 29N, and a side view is provided in 290.

[0202] Example 3 - Effect of velocity on the width of a bead

[0203] Referring to FIG. 30A, a smear nozzle 3050 was used to deposit a bead of “3M VHB” Extrudable Tape from a Nordson “PROBOND” dispenser. The smear nozzle 3050 had an outer diameter (OD) of 20 mm and an inner diameter (ID) of 4 mm.

[0204] Referring to FIG. 30B, a top view photograph is provided of a steel panel workpiece substrate

[0205] 3040 upon which three different beads 3010a, 3010b, and 3010c were deposited, starting near a first edge

[0206] 3041 of the workpiece substrate 3040 and ending near an opposing second edge 3043 of the workpiece substrate 3040. As can be seen, the bead 3010a has the largest width, the bead 3010c has the smallest width, and the width of the bead 3010b is in between the widths of the beads 3010a and 3010c. This demonstrates the effects of changing velocity of bead deposition on a substrate, from a slowest velocity for bead 3010a at 20 mm / s, then a medium velocity for bead 3010b at 30 mm / s, to a fastest velocity for bead 3010c at 40 mm / s. It is noted that it is only possible to smear a full width of a bead that has a width either the same or smaller than the outer diameter of the smear nozzle.

[0207] FIGS. 30C-30E are photographs of the widths of beads of material at different bead deposition velocities. In particular, FIG. 30C shows a width W of bead 3010a when deposited from the nozzle 3050 at a velocity of 20 mm / s. FIG. 30D shows a width W of bead 3010b when deposited from the nozzle 3050 at a velocity of 30 mm / s. FIG. 30E shows a width W of bead 3010c when deposited from the nozzle 3050 at a velocity of 40 mm / s.

[0208] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and / or equivalent implementations can be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof.

[0209] Furthermore, all publications and patents referenced herein are incorporated by reference in their entirety to the same extent as if each individual publication or patent was specifically and individually indicated to be incorporated by reference. In the event of inconsistencies or contradictions between portions of the incorporated references and this application, the information in the preceding description prevails.

Claims

What Is Claimed Is:

1. A method of controlling a bead shape of a dispensed bead of material along a dispensing path, the method comprising: adjusting at least one of a) a robot path parameter or b) a dispenser parameter using at least one of i) a user input or ii) a feedback from a sensor, to vary the bead shape of the dispensed bead of material based on a characteristic of the workpiece.

2. The method of claim 1, wherein the characteristic of the workpiece comprises at least one of the following: a change in height, a change in width, a wall, a rib, a seam, an edge, a change in a bonding strength need, a gap in portions needing a bead of material, or a portion where a head and a tail of the bead of material have a junction.

3. The method of claim 1 or claim 2, wherein the variation of the bead shape comprises at least one of the following: a variation in bead height, a variation in bead width, a blend of one portion of a bead with a second portion of a bead, a variation in cross-sectional shape of the bead, or a creation of a gap between adjacent sections of the bead in the dispensing path.

4. The method of any of claims 1 to 3, wherein the variation of the bead shape comprises a blend of one portion of a bead with a second portion of a bead.

5. The method of claim 4, wherein the blend is at a junction of a head and a tail of the bead of material.

6. The method of any of claims 1 to 5, wherein the variation of the bead shape comprises a creation of at least one gap between adjacent sections of the bead in the dispensing path.

7. The method of claim 6, wherein the adjacent sections of the bead in the dispensing path comprise a junction of the head and the tail of the bead of material.

8. The method of any of claims 1 to 7, wherein the adjusting comprises a robot path parameter comprising at least one of a tool velocity, a tool orientation, or tool position.

9. The method of any of claims 1 to 8, wherein the adjusting comprises a dispenser parameter comprising at least one of a feed rate, an on / off timing, a nozzle inner diameter, a nozzle outer diameter, or a nozzle cross-sectional shape.

10. The method of any of claims 1 to 9, wherein the dispenser is attached to a robot.

11. The method of any of claims 1 to 10, wherein the workpiece is supported by a robot.

12. The method of any of claims 1 to 11, wherein the adjusting is based at least in part on the feedback from a sensor selected from the group consisting of a light detection and ranging(LIDAR) system; a laser profilometer; an area snapshot sensor; a triangulation-based sensor; a time-of-flight sensor; a laser point sensor; an optical coherence tomography sensor; a confocal sensor; a dynamic vision sensor; a red, blue, and green (RBG) camera; a red, blue, green, and depth (RBGD) camera; a black and white (B&W) camera; and a three-dimensional (3D) image sensor.

13. The method of any of claims 1 to 12, wherein the adjusting is based at least in part on the user input selected from the group consisting of tool position, tool velocity, tool orientation, dispenser parameters, nozzle type, on / off timing, feed rate, bead thickness, bead width, bead location, or bead bonding strength.

14. The method of any of claims 1 to 13, wherein the material has a melt viscosity of 100 Pascal- Seconds to 1000 Pascal-Seconds at 190°C and a shear rate of 10 sec'1, of 50 Pascal-Seconds to 500 Pascal-Seconds at 190°C and a shear rate of 100 sec'1, or 1 Pascal-Seconds to 100 Pascal- Seconds at 190°C and a shear rate of 1000 sec'1.

15. A method of optimizing a non-linear robotic trajectory of deposition of a bead material, the method comprising: a) obtaining a nominal deposition path; b) selecting at least one process parameter; c) optimizing the deposition path using the at least one process parameter and at least one path or parameter tolerance to create an adjusted deposition path; d) checking for at least one issue along the adjusted deposition path; and e) finalizing the adjusted deposition path.

16. The method of claim 15, further comprising determining that there is an issue along the adjusted deposition path and repeating operations b) through d) at least once prior to performing operation e).

17. The method of claim 15 or claim 16, wherein the issue comprises at least one of a robotic collision, a singularity, joint limits, dynamic limits, discontinuity in acceleration and velocity profile, non-uniformity of deposited material, undesirable tool configurations, or workspace limits.

18. The method of claim 16 or claim 17, further comprising determining that the nominal deposition path cannot be sufficiently optimized without causing at least one issue along the adjusted deposition path and requesting at least one of 1) a different nominal deposition path or 2) at least one different i) path or ii) parameter tolerance.

19. The method of any of claims 15 to 18, wherein the at least one process parameter comprises a dispenser flow rate, a dispenser nozzle width, a tool velocity, a tool acceleration, a tool jerk, or a tool orientation.

20. The method of any of claims 15 to 19, wherein the optimizing comprises analyzing a curvature of the nominal deposition path and adjusting at least one of a distance between adjacent path points, a time between adjacent path points, or a radius of the deposition path.

21. The method of any of claims 15 to 20, wherein at least a portion of the finalized adjusted deposition path comprises a larger radius of curvature than the nominal deposition path.

22. The method of any of claims 15 to 21, wherein the obtaining comprises creating a nominal deposition path.

23. The method of any of claims 15 to 22, wherein the adjusted deposition path is optimized for a robot having six degrees of freedom to implement the non-linear robotic trajectory of deposition of the bead material.

24. A method of depositing a bead of material in a non-linear path, the method comprising optimizing a non-linear robotic trajectory of deposition of a bead material according to any of claims 15 to 23; and depositing the bead of material in the finalized adjusted path.

Images