ROBOTIC END EFFECTOR SYSTEM AND METHOD
A robotic end effector system and method having a plurality of end effectors which are selectively suitable for particular applications on a workpiece. The end effectors include a resident controller adapted to execute tasks specific to the end effector and are rapidly attachable and removable from the robot for easy change over to different workpieces.
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This application claims priority to U.S. Provisional Application Ser. No. 61/145,695 filed Jan. 19, 2009 and U.S. Provisional Application Ser. No. 61/160,893 filed Mar. 17, 2009 both applications incorporated herein by reference in their entirety.
BACKGROUNDThe use of automated robots in manufacturing and assembly facilities has become commonplace for the efficient assembly of large and small, simple and complex devices and machines. One example of an application which has become more complex requiring the use and coordination of numerous robots is in the manufacture and assembly of automotive vehicles.
An assembly line in a manufacturing facility may include a fluid applying system for applying fluid, such as a bead of sealant or adhesive, to a workpiece. Other applications include clamping two or more pieces together to be transferred, welded or secured together. In a technologically advanced facility, one or more of these operations, and typically most of them, require the use of robots. In the past, such robots were typically set-up, tooled and programmed to carry out a specific task, for example, welding or adhering certain pieces together, application of fasteners used later in an assembly process or coating with paint or other material protectant. Once set-up and programmed, it was laborious and time consuming to change the robot tooling or programming to re-task the robot to function in a different capacity or application. This made it difficult, time consuming and costly to, for example, change from the manufacture and assembly of one vehicle type to another. Thus, one a robot was set-up and programmed, that robot was dedicated to that application and was not useful to use in other applications or tasks without substantial changeover time.
In one manufacturing and assembly application to provide fluid adhesive or sealant to a workpiece, for example a sheet metal vehicle body, typically such a fluid supply system includes a robot having a nozzle for applying fluid to the workpiece. The robot receives fluid from a fluid supply, such as one or more industrial sized drums of the fluid, disposed near the robot. A fluid supply line extends from at least one of the drums to the robot. The fluid supply line is often fixed to a ceiling or other support above the robot. An end of the fluid supply line coupled to the robot is typically a coiled line in order to prevent the fluid supply line from restricting movement of the robot, and the coiled line is in fluid communication with the robot. Such systems often required pumps and other capital equipment, sizable floor space and were very expensive. Further, changing from one fluid to another, for example to a different adhesive or sealant, required changing fluid lines and cleaning the existing line to comply with regulations and purity of the alternate fluid to be used. The robot can thus move the nozzle into an application position relative to the workpiece, and the nozzle can apply fluid to the workpiece. Additionally, other components, such as a pump and a control system, are typically necessary for operation of the system.
Similarly, other robotic applications such as metal-to-metal spot welding, application of weld studs, and automated clamping and component transferring systems suffered from the same disadvantages.
SUMMARYA robotic end effector system and method is disclosed for use in the manufacturing and assembly of devices, for example, automotive sheet metal bodies and associated vehicle systems. The effector system allows a suitable robot to quickly change an end effector, for example an end effector used for applying an adhesive or sealant, to another end effector, for example a weld gun. The system and method substantially eliminates, or eliminates altogether, past restraints on dedicated robots for specific applications or tasks and provides for greatly increased flexibility of the robot to change tasks for more efficient use and efficient manufacturing and assembly as a whole.
The end effector system and method uses a connector and data communication links or means so that the end effector itself can include an on-board or on-effector controller to receive and/or execute programs specific to the type of effector in use by the robot. On a need to change the application of the robot, the end effector may be disconnected from the robot connector and a new or alternate effector or appliance can be picked-up or otherwise secured to the robot, communication re-established between the effector and the robot, or other communication equipment, and the robot is retasked to another application or use.
In an example of a fluid applying robot, for example the application of an adhesive or sealant, the end effector can include a receptacle for receiving and temporary holding of a canister of fluid. The robot, or preferably the end effector, can include a plunger or another structure for controlling the flow of fluid from the canister, and the robot can move the canister into a fluid applying position relative to the workpiece. With the canister in the fluid applying position, the plunger can be actuated to cause fluid to flow from the canister. When the canister is empty or a different fluid is required, the robot can maneuver to dispose of the canister and can obtain a new canister. In one example, the robot or end effector can include a blade or other cutting mechanism for removing a portion of an empty canister that contains any remaining fluid.
The example of an end effector described herein for applying a fluid applying robot as described herein can have many advantages over known fluid applying systems. For example, the fluid applying robot can cost an order of magnitude less than known fluid applying systems, at least in part because the fluid applying robot as described herein can be used without the complex fluid storage and transport components of known fluid applying systems. Further, the fluid applying robot can be much more versatile than known fluid applying systems, as the fluid applying robot can be more easily moved in order to reconfigure an assembly line since the fluid applying robot can be used without separate components, some of which may be fixed in place. Additionally, the fluid applying robot as described herein can also be more versatile than known fluid applying systems since changing the fluid applied by the fluid applying robot can be accomplished by the robot obtaining a new fluid canister. Finally, disposal of empty canisters can be less expensive than cleaning the fluid sources used by known fluid applying systems since the plunger of the fluid applying robot can remove almost all of the fluid from the canister such that the only portion of the canister that should be cleaned is the portion removed by the blade.
These advantages are also achievable with many other robotic end effectors including welding, for example changing the particular spot welding gun end effector to access and weld in a different area or applying a different weld stud or in a different location. An end effector which provides a holding or clamping fixture or function, may be quickly changed to clamp alternate components or in different areas.
The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
Examples of a robotic end effector system 10 and method are shown in
In one example shown in
Referring again to
Referring to
An example of an end effector 10 in the form of an end effector 60 useful for applying a fluid, for example an adhesive or sealant, is shown in
The fit between the backing plate 100 and interior diameter of the canister 90 can be sufficiently tight such that the backing plate 100 scrapes fluid from interior walls of canister 90. As a result, only a small amount of fluid can remain in the canister 90 after the backing plate 100 is fully depressed, and the effort required to clean the canister 90 can be reduced. Further, the fit between the needle 104 and the nozzle 98 can be sufficiently tight such that the needle 104 scrapes fluid from interior walls of the nozzle 98. As a result, the effort required to clean the portion of the nozzle 98 scraped by the needle 104 can be greatly reduced.
Referring to
In the exemplary adhesive end effector 60, the end effector 60 can also include a plunger 126 and a servo motor 132 (shown schematically in
As shown in
The exemplary end effector 60 (or 10) can additionally include a second sensor 146, which can be a camera, an ultrasonic sensor, or another sensors known by those skilled in the field. As shown in
In a further example of adhesive end effector 60,
As an example of interaction between the end effector 60 and tray 150, each canister receiving slot 154 can include a hole sized to receive the nozzle 98 of one of the canisters 90. The controller 54 can instruct the servos 46 to move the robot 16 such that the end effector 60 is in a position to move vertically to insert the nozzle 98 into the canister receiver slot 154, and the end effector 60 can be controlled to at least partially insert the nozzle 98 into the slot 154. Once the nozzle 98 is at least partially in the slot 154, the controller 54 can instruct the servo 132 to disengage the plunger 126 from the canister 90, and the robot 16 can move the end effector 60 laterally relative to the canister receiving slot 154. Engagement between the nozzle 98 and canister receiving slot 154 can retain the canister 90 in position relative to the canister receiving slot 154 while the receptacle 80 is moved laterally away from the canister receiving slot 150, thereby disengaging the receptacle 80 and canister 90. The canister 90 can then be propelled by gravity into the canister receiving slot 154. The robot 16 can move the empty receptacle 80 into position to engage another canister 90 by laterally moving the receptacle 80 to engage one of the canisters 90 by sliding between the canister 90 and tray 150, then vertically lifting the canister 90 from the tray 150.
Alternatively, new canisters 90 can be loaded into the receptacle 80 in different ways known by those skilled in the field. For example, the end effector 60 can include a canister hopper (not shown) containing a stack of canisters 90. A new canister 90 from the hopper can be released into the receptacle after disposing of the canister 90 previously in the receptacle 80. As another example, canisters 90 can be loaded or unloaded by hand or by use of another robot.
In another example, one of the robot 16 and end effector 60 can also include a cutter 156 as shown in
In an example of an alternate end effector 10, an effector useful for positioning and securing a weld stud to a workpiece 30 is generally illustrated in
In an alternate example of an end effector 10 useful with a robot 16 in the herein described end effector system described is illustrated in
In the example shown in
In an alternate example of an end effector 10 useful with robot 16 in the herein described end effector system is illustrated in
Although several alternate examples of end effectors 10 have been illustrated and described, other end effectors 10 known by those skilled in the art are useful in the inventive system and method. For example, instead of spot weld gun effector 66, a laser or other seam or bead welding device may be used. As an alternate to an alternate adhesive or sealant effector 60, a paint or other surface coating, or part cleaning fluid applying effectors may be used. Alternate fluids, for example compressed air or lubricating oils or fluids may be used.
Referring to
Referring to
As best seen in
In the example, connector 220 may further include an angle bracket 250 that connects to one end of plate 224 (to first end 228 in the example). Attached to bracket 250 is socket 256 which, as best seen in
In the example illustrated, connector system 220 further includes a plug 266 preferably affixed to the appliance or end effector 10, a weld gun end effector 66 in the illustrations. Plug 266 provides the appropriate service lines (not shown) needed into the end effector 10 (shown as 66 for illustrative purposes only). As best seen in
An advantage of connector 220 over prior designs is its ability to substantially maintain or only minimally alter the center of gravity (CG) and tool center point (TCP) of an end effector 10 (illustrated as effector 66) while permitting all of the advantages described herein and as known by those skilled in the art. This is advantageous as relatively little or no reprogramming, readjustment or other modifications is required to change end effector 10 as described herein.
It is understood that connector 220 may be attached to other parts of end effector 66 (or 10) other than in the position shown in
Although connector 220 is shown with a weld gun end effector 66, connector 220 is useable with other end effectors 10 described herein and known by those skilled in the field. Further, connection schemes other than studs 274 into bracket slots 246 may be used as known by those skilled in the field. For example, other quick connect fasteners or temporary locking systems may be used to securely attach end effector 10 to robot 16 while allowing relatively quick release to change the end effector.
In operation to connect an appliance or end effector 10 to robot 16, an appliance or end effector 10 is selected to suit the particular process or operation needed on work pieces 30 in a workstation 24. The end effector, for example weld gun effector 66 includes studs 274 protruding outwardly and oriented so as to slide into slots 246 in brackets 240 as best seen in
The above-described examples have been described in order to allow easy understanding of the invention and do not limit the invention. On the contrary, the invention is intended to cover various modifications and equivalent arrangements, whose scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structure as is permitted under the law.
Claims
1. A robotic end effector apparatus for use with a multi-axis robot having a movable wrist, the apparatus comprising:
- a connector removably attached to the robot wrist; and
- an end effector removably engageable with the connector, the end effector having a tool operable on a work piece.
2. The device of claim 1 wherein the end effector further comprises a controller mounted to the effector and a motor in electronic communication with the controller for imparting movement of at least one component of the tool for use on the workpiece.
3. The device of claim 1 wherein the controller includes a microprocessor and memory storage, the controller is in electronic communication with at least one other controller for the electronic receipt by the effector controller of data specific to the effector.
4. The apparatus of claim 2 wherein the end effector further comprises:
- a fluid applicator comprising:
- a replacable canister defining a chamber at least partially containing fluid and having a nozzle in fluid communication with the chamber,
- a receptacle adapted to receive the canister; and
- a plunger operable to force fluid from the chamber.
5. The apparatus of claim 4 wherein the controller is in electronic communication with a motor in driving engagement with the plunger, wherein on a selective activation signal from the controller, the motor drives the plunger to force fluid from the canister chamber through the nozzle.
6. The apparatus of claim 4 wherein the receptacle includes an open trough defining a cavity for receipt of the canister in the cavity, the receptacle further defining an end wall having an aperture for through receipt of the canister nozzle for orientation of the nozzle in a direction toward the workpiece.
7. The apparatus of claim 4 further comprising at least one sensor in electronic communication with the effector controller for active monitoring a fluid bead exiting the canister nozzle.
8. The apparatus of claim 4 wherein the canister further comprises a backplate in communication with the chamber, the backplate further having a needle extending into the chamber oriented toward the nozzle, wherein on movement of the backplate toward the needle, the needle enters at least a portion of the nozzle to force additional fluid from the chamber through the nozzle.
9. The apparatus of claim 4 further comprising a tray for holding a plurality of canisters proximate the end effector, the tray adapted to release the canisters through engagement of the end effector with at least one of the canisters.
10. The apparatus of claim 4 further comprising a cutter positioned proximate the end effector, the cutter operable to remove a selected portion of the canister nozzle.
11. The apparatus of claim 1 wherein the end effector tool is one of a welding gun and a clamping fixture.
12. The apparatus of claim 1 wherein the connector further comprises:
- a plate connected to the robot wrist;
- a socket connected to the plate, the socket in communication with at least one service line from the robot wrist;
- a plug connected to the end effector in communication with at least one service line of the end effector, wherein on engagement of the end effector to the plate, the effector plug engages the socket for communication of the at least one service line from the robot wrist to the service line of the end effector.
13. The connector of claim 12 wherein the plate further comprises at least one bracket having a slot for adapted sliding receipt of a stud connected to the end effector for removable engagement of the end effector with the plate.
14. The connector of claim 13 wherein engagement of the end effector to the connector does not substantially alter at least one of the center of gravity or the tool center point of the end effector.
15. A quick-release connector for use in connecting a robot having a movable wrist to a selected end effector, the connector comprising:
- a plate connected to the robot wrist; a socket connected to the plate, the socket in communication with at least one service line from the robot wrist; a plug connected to the end effector in communication with at least one service line of the end effector, wherein on engagement of the end effector to the plate, the effector plug engages the socket for communication of the at least one service line from the robot wrist to the service line of the end effector.
16. The connector of claim 15 wherein the plate further comprises at least one bracket having a slot for adapted sliding receipt of a stud connected to the end effector for removable engagement of the end effector with the plate.
17. The connector of claim 15 wherein engagement of the end effector to the connector does not substantially alter at least one of the center of gravity or the tool center point of the end effector.
18. A method of rapidly attaching an end effector useful on a workpiece from operable engagement with a robot having a movable wrist and at least one service line extending from the wrist, the method comprising the steps of:
- identifying the work to be done on the workpiece;
- selecting one of a plurality of end effectors having at least one service line;
- engaging the end effector to the robot wrist such that the service line of the robot wrist is in communication with the end effector service line.
19. The method of claim 18 further comprising the step of establishing electronic communication between a controller mounted on the end effector with at least one controller not mounted to the end effector.
20. The method of claim 19 further comprising the step of actuating electronic instructions specific to the selected end effector for use on the workpiece.
Type: Application
Filed: Jan 19, 2010
Publication Date: Jul 22, 2010
Applicant: COMAU, INC. (Southfield, MI)
Inventors: Velibor Kilibarda (Birmingham, MI), Joseph Cyrek (Southfield, MI), David Reid (Commerce Twp, MI)
Application Number: 12/689,993
International Classification: B25J 17/02 (20060101); B23P 11/00 (20060101); B05C 5/00 (20060101); B23K 9/00 (20060101);