Method for the flexible assembly of assemblies

• US 5,239,739 A
• Filed: 10/09/1992
• Issued: 08/31/1993
• Est. Priority Date: 04/01/1991
• Status: Expired due to Term

• Current Assignee: Fanuc Robotics America Incorporated (Fanuc Corporation)
• Original Assignee: Gmfanuc Robotics Corporation
• Inventors: Hautau, Lane A., Akeel, Hadi A.
• Primary Examiner(s): Rosenbaum, Mark
• Assistant Examiner(s): VO, PETER DUNG BA
• Application Number:
  US07/959,454
• Time in Patent Office: 326 Days
• Field of Search: 29/281.5, 29/281.6, 29/407, 29/429, 29/430, 29/445, 29/466-469, 29/563, 29/709, 29/711, 29/712, 29/771, 29/791, 29/822, 29/787, 269/45, 269/266, 269/296, 318/568.13-568.18, 364/468, 364/478, 901/15, 901/42
• US Class Current: 29/430
• CPC Class Codes: B23K 37/047 moving work to adjust its position between soldering, welding or cutting steps B23K37/053 takes precedence
• CPC Class Codes: B23P 21/00 Machines for assembling a multiplicity of different parts to compose units, with or without preceding or subsequent working of such parts, e.g. with programme control
• CPC Class Codes: B23P 2700/50 Other automobile vehicle parts, i.e. manufactured in assembly lines
• CPC Class Codes: B62D 65/02 Joining sub-units or components to, or positioning sub-units or components with respect to, body shell or other sub-units or components
• CPC Class Codes: G05B 19/41805 characterised by assembly
• CPC Class Codes: G05B 2219/50052 Orienting workpiece relative to tool
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
• CPC Class Codes: Y10T 29/49829 Advancing work to successive stations [i.e., assembly line]
• CPC Class Codes: Y10T 29/49899 by multiple cooperating aligning means
• CPC Class Codes: Y10T 29/49904 Assembling a subassembly, then assembling with a second subassembly
• CPC Class Codes: Y10T 29/53052 including position sensor

Abstract

A method and system for the flexible assembly of components into an assembly at an assembly station within an assembly area in an adaptive, programmable fashion. Several programmable locators mounted on a platform work cooperatively to receive and support components or parts having critical positioning features at approximate locations. The programmable locators then move the components so that the critical positioning features and hence the components are at desired locations. Thereafter, part position and orientation are constrained at retaining locations while the components are in their desired locations. Processing equipment at least partially joins the retained components either at the assembly station or at a separate processing station. One of the programmable locators may provide one of the retaining locations. Preferably, at least one sensor mounted on one of the programmable locators provides at least one feedback signal for a control means which controls at least one programmable locator to adapt its position with respect to at least one critical feature of its part to thereby relocate the part. In this way, verification of the accuracy of the positioning and holding is provided.

Claims

1. A method for flexibly assembling components to form an assembly of the components at an assembly station within an assembly area;

each of the components having at least one critical positioning feature and a plurality of support locations definable relative to the at least one critical positioning feature, the assembly station including a base and a plurality of programmable locators mounted and constrained at predetermined locations on the base to define a base coordinate frame, each of the programmable locators being controlled by control means having a first set of programs to move under program control within a work envelope, the method comprising the steps of;

(a) receiving and cooperatively supporting the components by the plurality of programmable locators at support locations of the components, each of the components being received and cooperatively supported by at least one of the programmable locators at at least one of said support locations of the component;

(b) independently moving the programmable locators under program control of one of the first set of programs hence adjusting the support locations of each of the plurality of components with reference to the base coordinate frame, such that the at least one critical positioning feature of each component is located at its respective desired position, hence, defining a desired position for each of the components and wherein the desired position of each component is determined by the collective movement of multiple programmable locators;

(c) retaining the plurality of components in their respective desired positions, each of the components being retained at a plurality of retaining locations, and each of the components being constrained at its retaining locations relative to the base; and

(d) providing process equipment for at least partially joining the components in their respective desired locations to obtain the assembly of the components.

2. The method of claim 1 further comprising the step of generating at least one location signal representing the actual location of the at least one critical positioning feature of one of the components in the base coordinate frame, wherein the one of the components of the assembly is moved based on the at least one location signal during the step of adjusting.

3. The method of claim 1 or claim 2 further comprising the step of moving the constrained components from the assembly station to a processing station, the processing station including the processing equipment to join the components.

4. The method of claim 1 or claim 2 wherein a given component of the assembly is retained at at least one of its retaining locations by another component of the assembly.

5. The method of claim 1 of claim 2 wherein a processing station including the processing equipment is coincident with the assembly station.

6. The method of claim 1 or claim 2 wherein at least one of the programmable locators has at least two degrees of freedom.

7. The method of claim 2 wherein the assembly station includes a reference locator for providing a global reference for the other locators.

8. The method of claim 7 wherein the reference locator is mounted at a predetermined location on the base.

9. The method of claim 2 wherein one of the programmable locators is a reference locator mounted at its predetermined location to at least partially define the base coordinate frame.

10. The method of claim 7 or claim 8 or claim 9 wherein the reference locator receives and supports the one of the components and wherein the step of generating includes the step of sensing the location of the at least one critical positioning feature of the one of the components to provide at least one feedback signal.

11. The method of claim 10 further comprising the step of processing the at least one feedback signal to obtain a processed signal, the processed signal being utilized to move the one of the components under control of its one of the first set of programs to its desired location.

12. The method of claim 9 further comprising the step of moving the base so that the constrained components are transferred to a processing station including the process equipment.

13. The method of claim 9 further comprising the step of unloading the assembly from the base.

14. The method of claim 13 further comprising the steps of moving the unloaded assembly to a finish processing station including finish processing equipment and utilizing the finish processing equipment at the finish processing station to finish processing the assembly.

15. The method of claim 2 wherein the assembly station includes at least one sensor for providing at least one feedback signal, the at least one feedback signal being utilized by the control means to generate the at least one location signal.

16. The method of claim 10 wherein the assembly station includes at least one sensor for accomplishing the step of sensing, the at least one feedback signal being utilized by the control means to control the at least one of the programmable locators.

17. The method of claim 1 or claim 2 wherein several of the plurality of programmable locators are adapted to receive and support one of the plurality of components at its support locations and wherein the method further comprises the step of synchronizing the several of the plurality of programmable locators to effect a common displacement of the one of the components during the step of adjusting.

18. The method of claim 1 wherein at least one of the components is retained at its desired locations by at least one of the plurality of programmable locators.

19. The method of claim 1 wherein the at least one of the programmable locators moves its component along a programmed path provided by its one of the first set of programs to its desired location.

20. The method of claim 1 wherein the at least one of the programmable locators retains its component in its desired location at at least one of the retaining locations.

21. The method of claim 7 wherein the reference locator is programmable.

22. The method of claim 15 wherein the at least one sensor is a camera mounted on one of the programmable locators.

23. The method of claim 15 wherein the at least one sensor is mounted on the programmable locator which moves the one of the components.

24. The method of claim 1 wherein the at least one of the programmable locators both retains and processes its component in its desired location at at least one of its retaining locations.

25. The method of claim 12 or claim 13 further comprising the step of releasing at least one of the components at at least one of its plurality of retaining locations after the components are joined to obtain the assembly, the joined components being maintained in their desired locations at the remainder of the plurality of retaining locations.

26. The method of claim 1 wherein at least one of the programmable locators is a material handling robot.

27. The method of claim 1 wherein the process equipment includes a processing robot.

28. The method of claim 14 wherein the steps of unloading and moving are accomplished by a material handling robot for picking up and placing the joined components in the finish processing station.

29. The method of claim 1 further comprising the steps of storing at least one of the components within the work envelope of a material handling robot and loading the at least one of the components at its support locations with the robot.

30. The method of claim 12 wherein the base is a rotary table and wherein the step of moving includes the step of rotating the rotary table to transfer the constrained components to the processing station from the assembly station.

31. The method of claim 1 or claim 9 or claim 12 or claim 30 wherein the base is a trapezoidal rotary table to reduce horizontal floor space requirements and allow gravity to at least partially locate at least one of the components in its support locations.

32. The method of claim 1 further comprising the steps of performing steps (a) through (d) to obtain another assembly.

33. The method of claim 32 further comprising the step of assembling the assembly and the another assembly by performing steps (a) through (d) with the assemblies to obtain a body assembly.

34. The method of claim 1 wherein the control means has a second set of programs different from the first set of programs and wherein the method further comprises the step of selecting one of the first and second sets of programs so that the plurality of programmable locators move their components under control of a selected set of the first and second sets of programs.

35. The method of claim 1 or claim 2 further comprising the step of clamping at least one of the components in its support locations wherein the step of adjusting includes cooperatively moving the locators to relocate the at least one of the components such that its at least one critical positioning feature is at its desired location.

36. The method of claim 1 or claim 2 further comprising the step of cooperatively moving the locators and the process equipment to provide increased support and reduce the number of locators.

37. The method of claim 1 or claim 2 further comprising the step of cooperatively moving the locators and the process equipment, where the locators are part of the process equipment providing support and/or communicating the process medium.

38. The method of claim 1 or claim 2 wherein each of the programmable locators is movable within its work envelope completely independently of each of the other programmable locators.