阅读说明：本技术 无夹具部件组装 (Clamp-free component assembly ) 是由 M·A·塞斯 J·P·斯派瑟 R·斯格克斯 于 2020-01-22 设计创作，主要内容包括：一种组装多个子部件以形成成品部件的方法包括用第一臂端工具抓取第一子部件,其中所述第一臂端工具附接到第一机器人臂,并且用第二臂端工具抓取第二子部件,其中所述第二臂端工具附接到第二机器人臂。移动所述第一和第二臂端工具以将所述第一子部件相对于所述第二子部件定位在预组装位置,并且接着移动所述第一和第二臂端工具以接合所述第一和第二子部件的接口表面。用附接到接合机器人臂的接合工具在所述第一子部件与所述第二子部件之间形成接合点以便由此组装所述成品部件。(A method of assembling a plurality of sub-components to form a finished component includes grasping a first sub-component with a first end-of-arm tool, wherein the first end-of-arm tool is attached to a first robotic arm, and grasping a second sub-component with a second end-of-arm tool, wherein the second end-of-arm tool is attached to a second robotic arm. Moving the first and second end of arm tooling to position the first sub-part in a pre-assembly position relative to the second sub-part, and then moving the first and second end of arm tooling to engage the interface surfaces of the first and second sub-parts. Forming a joint between the first sub-part and the second sub-part with a joining tool attached to a joining robot arm to thereby assemble the finished component.)

1. A method of assembling a plurality of sub-components to form a finished component, the method comprising:

grasping a first sub-part with a first end-of-arm tool, wherein the first end-of-arm tool is attached to a first robot arm;

grasping a second sub-part with a second end-of-arm tool, wherein the second end-of-arm tool is attached to a second robotic arm;

moving the first and second end of arm tooling to position the first sub-assembly in a pre-assembly position relative to the second sub-assembly;

visually positioning interface surfaces on the first and second sub-components using a camera;

estimating an offset between the pre-assembly position and a desired assembly position;

moving the first and second end of arm tools to engage the interface surfaces of the first and second subcomponents;

moving the first and second sub-members to the desired assembly position, measuring torsional and lateral forces exerted on the first and second sub-members by the first and second end-of-arm tools with sensors mounted on the first and second end-of-arm tools, and determining when the first and second sub-members are in the desired assembly position based on the torsional and lateral forces;

scanning the first and second sub-components with a non-contact measuring device and locating an assembly datum; and

comparing the positions of the first and second subcomponents with the desired assembly position.

2. The method of claim 1, further comprising:

after comparing the positions of the first and second subcomponents with the desired assembly position;

forming a joint between the first and second subcomponents with a joining tool attached to a joining robot arm to thereby assemble the finished component.

3. The method of claim 2, further comprising:

after forming a joint between the first and second subcomponents with a joining tool attached to a joining robot arm to thereby assemble the finished component;

the finished part is scanned to verify geometry.

4. The method of claim 1, further comprising:

after scanning the first and second sub-components and locating an assembly reference point with a non-contact measuring device and comparing the position of the first and second sub-components to the desired assembly position;

moving the first and second subassemblies to the desired assembly position within the established tolerance range.

5. The method of claim 1, further comprising:

after scanning the first and second sub-components and locating an assembly reference point with a non-contact measuring device and comparing the position of the first and second sub-components to the desired assembly position;

moving the first and second sub-members to a thermal deformation compensation position.

6. The method of claim 2, further comprising:

after scanning the finished part to verify geometry;

moving the first and second robotic arms and plastically deforming the finished part.

7. The method of claim 1, wherein visually positioning the interface surface on the first and second sub-components using a camera further comprises visually positioning the interface surface on the first and second sub-components using a stationary camera.

8. The method of claim 1, wherein visually positioning the interface surfaces on the first and second sub-components using a camera further comprises moving a camera mounted to an inspection robot arm to an inspection position and visually positioning the interface surfaces on the first and second sub-components using the camera.

9. The method of claim 1, further comprising:

grasping a third sub-part with a third end-of-arm tool, wherein the third end-of-arm tool is attached to a third robotic arm;

moving the third arm end tool to position the third sub-assembly in a pre-assembly position relative to the first and second sub-assemblies;

visually positioning an interface surface of the third sub-component using a camera;

estimating an offset between the pre-assembly position and a desired assembly position;

moving the third end of arm tool to engage the interface surfaces of the first, second and third subcomponents;

moving the third sub-part to the desired assembly position, measuring torsional and lateral forces exerted on the third sub-part by the third end-of-arm tool with a sensor mounted on the third end-of-arm tool, and determining when the third sub-part is in the desired assembly position based on the torsional and lateral forces;

scanning the third sub-part with a non-contact measuring device and locating an assembly reference point; and

comparing the position of the third sub-part to the desired assembly position.

10. The method of claim 9, further comprising:

after comparing the positions of the first, second and third subcomponents with the desired assembly position;

forming a joint between the first and second subcomponents with a joining tool attached to a joining robotic arm, and forming a joint between the second and third subcomponents with a joining tool attached to a joining robotic arm, to thereby assemble the finished component.

Technical Field

The present disclosure relates to a clampless component assembly system and a method of assembling components.

Background

Manufacturing systems typically move, translate, or otherwise manipulate parts, subassemblies, and/or assemblies that must be accurately positioned and held in place in order to perform manufacturing and assembly operations. For example, sheet metal parts or panels, subassemblies or components may need to be accurately positioned and held in place for assembly, welding and inspection operations in a vehicle assembly plant or along an assembly line for items such as appliances, aircraft, furniture, and electronics. Part positioning fixtures are commonly used for this purpose.

Part positioning fixtures typically include a plurality of fixing pins configured to fit into a plurality of positioning holes defined by the part and one or more clips configured to hold the part in place. Part locating fixtures are typically only capable of being used with one particular part size and/or shape and typically require modification or reconfiguration to locate and hold parts of different sizes and/or shapes. A variety of parts in a manufacturing plant and a variety of assembly and manufacturing operations typically require multiple part positioning fixtures. Thus, while the present system achieves its intended purpose, there remains a need for a new and improved system and method for assembling components, and more particularly, for assembling components using a clampless component assembly system.

Disclosure of Invention

According to several aspects of the present disclosure, a method of assembling a plurality of sub-components to form a finished component includes grasping a first sub-component with a first end-of-arm tool, wherein the first end-of-arm tool is attached to a first robotic arm, and grasping a second sub-component with a second end-of-arm tool, wherein the second end-of-arm tool is attached to a second robotic arm. The first and second end of arm tooling are moved to position the first sub-assembly in a pre-assembly position relative to the second sub-assembly, and then the first and second end of arm tooling are moved to engage the interface surfaces of the first and second sub-assemblies. The interface surfaces of the first and second sub-components are visually positioned using a camera and an offset between the pre-assembly position and the desired assembly position is estimated. The first and second end of arm tools are moved to engage the interface surfaces of the first and second subassemblies and move the first and second subassemblies to the desired assembly position. The torque and lateral forces exerted by the first and second end of arm tools on the first and second subassemblies are measured with sensors mounted on the first and second end of arm tools, and a determination is made as to when the first and second subassemblies are in a desired assembly position based on the torque and lateral forces. The first and second sub-components are scanned with a non-contact measuring device and assembly fiducials are located and the positions of the first and second sub-components are compared to a desired assembly position.

According to another aspect of the disclosure, the method further includes, after comparing the positions of the first and second subcomponents with the desired assembly position, forming a joint between the first subcomponent and the second subcomponent with a joining tool attached to a joining robot arm to thereby assemble the finished component.

According to another aspect of the disclosure, the method further includes scanning the finished component to verify the geometry after forming a joint between the first and second subcomponents with a joining tool attached to a joining robot arm to thereby assemble the finished component.

According to another aspect of the disclosure, the method further includes moving the first and second sub-components to the desired assembly position within the established tolerance range after scanning the first and second sub-components with the non-contact measuring device and locating the assembly reference point and comparing the position of the first and second sub-components to the desired assembly position.

According to another aspect of the disclosure, the method further includes moving the first and second sub-components to a thermal deformation compensation position after scanning the first and second sub-components with the non-contact measuring device and locating an assembly reference point and comparing the position of the first and second sub-components to a desired assembly position.

According to another aspect of the disclosure, the method further includes moving the first and second robotic arms and plastically deforming the finished component after scanning the finished component to verify the geometry.

According to another aspect of the present disclosure, positioning the interface surfaces of the first and second subcomponents further includes visually positioning the interface surfaces of the first and second subcomponents using a fixed camera.

According to another aspect of the disclosure, positioning the interface surfaces of the first and second subcomponents further includes moving a camera mounted to the inspection robot arm to an inspection position and visually positioning the interface surfaces of the first and second subcomponents using the camera.

According to another aspect of the disclosure, the method further comprises grasping the third sub-component with a third end-of-arm tool, wherein the third end-of-arm tool is attached to the third robotic arm. The third arm end tool is moved to position the third sub-assembly in a pre-assembly position relative to the first and second sub-assemblies. The interface surface of the third sub-component is visually positioned using a camera and an offset between the pre-assembly position and the desired assembly position is estimated. The third end of arm tool is moved to engage the interface surfaces of the first, second and third subcomponents. The method further includes moving the third sub-assembly to a desired assembly position, measuring a torsional and lateral force exerted on the third sub-assembly by the third end-of-arm tool with a sensor mounted on the third end-of-arm tool, and determining when the third sub-assembly is in the desired assembly position based on the torsional and lateral forces. The third sub-part is scanned with a non-contact measuring device and an assembly reference point is located and the position of the third sub-part is compared to the desired assembly position.

In another aspect of the disclosure, the method further includes forming a joint between the first subcomponent and the second subcomponent with a joining tool attached to a joining robot arm and forming a joint between the second subcomponent and the third subcomponent with a joining tool attached to a joining robot arm after comparing the positions of the first, second and third subcomponents with the desired assembly position to thereby assemble the finished component.

According to several aspects of the present disclosure, a clamp-less component assembly system comprises: a first robot arm having a first end-of-arm tool mounted thereon and adapted to grasp a first sub-part; a second robot arm having a second end-of-arm tool mounted thereon and adapted to grasp a second sub-assembly; and a system controller adapted to control the first and second robot arms and the first and second end-of-arm tools to position the first and second sub-assemblies relative to each other. The inspection camera is in communication with the system controller and is adapted to visually position the interface surfaces of the first and second sub-components, wherein the system controller estimates an offset between the pre-assembly position and the desired assembly position. The sensors are mounted on the first and second end of arm tooling and are adapted to measure torsional and lateral forces exerted on the first and second sub-members by the first and second end of arm tooling as the first and second end of arm tooling move the first and second sub-members to a desired assembly position.

According to another aspect of the present disclosure, the clampless component assembly system further includes a joining robot arm having a joining tool mounted thereon, wherein the system controller controls the joining robot arm to bring the joining tool into a joined state with the first and second subcomponents and to join the first and second subcomponents to each other.

According to another aspect of the present disclosure, the bonding tool is a welding tool adapted to weld the first sub-component to the second sub-component.

According to another aspect of the disclosure, the first and second robot arms are adapted to be controlled by the system controller based on one of position control in which the positions of the first and second robot arms are controlled based on the three-dimensional positions of the robot arms within the given space, and force control in which the positions of the first and second robot arms are controlled based on the forces exerted by the first and second robot arms on the first and second end-of-arm tools measured by the first and second load cells.

According to another aspect of the present disclosure, the inspection camera is mounted in a fixed position.

According to another aspect of the disclosure, the inspection camera is mounted to an inspection robot arm, wherein the inspection robot arm is adapted to move the inspection camera to an inspection position to visually position the interface surfaces of the first and second sub-assemblies.

According to another aspect of the present disclosure, the clampless component assembly system further includes a third robotic arm having a third end-of-arm tool mounted thereon and adapted to grasp a third sub-component. Wherein the system controller is further adapted to control the third robot arm and the third arm end tool to position the third sub-part relative to the first and second sub-parts, the inspection camera is further adapted to visually position an interface surface of the third sub-part, and the system controller estimates an offset between the pre-assembly position and a desired assembly position, and the sensor is mounted on the third arm end tool and adapted to measure torsional and lateral forces exerted by the third arm end tool on the third sub-part as the third arm end tool moves the third sub-part to the desired assembly position.

According to another aspect of the present disclosure, the clampless component assembly system further includes a joining robot arm having a joining tool mounted thereon, wherein the system controller controls the joining robot arm to bring the joining tool into a joined state with the first, second, and third sub-components and to join the first, second, and third sub-components to each other.

According to another aspect of the present disclosure, the system controller is adapted to move the first, second, and third end-of-arm tools to a desired assembly position based on a comparison of the torsional and lateral forces measured by the sensors on the first, second, and third end-of-arm tools to a reference force target.

According to another aspect of the disclosure, the first and second robotic arms are adapted to apply a force to the first and second sub-components to deform the first and second sub-components to a thermal deformation compensation position prior to engaging the first, second and third sub-components, and to apply a force to the first and second sub-components to plastically deform the finished component after the first and second sub-components are engaged.

Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

Drawings

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

FIG. 1 is a perspective view of a clampless component assembly system according to an exemplary embodiment; and

FIG. 2 is a schematic flow diagram of a method of assembling components according to an example embodiment.

Detailed Description

The following description is merely exemplary in nature and is not intended to limit the application or uses of the present disclosure.

Referring to FIG. 1, a clipless component assembly system of the present disclosure is generally shown at 10. Component assembly system 10 includes a first robot arm 12 having a first end-of-arm tool 14 mounted thereon, a second robot arm 16 having a second end-of-arm tool 18 mounted thereon, and a third robot arm 20 having a third end-of-arm tool 22 mounted thereon. The first end of arm tool 14 is adapted to grasp the first sub-assembly 24 and hold the first sub-assembly 24 during the assembly process. The second end of arm tool 18 is adapted to grasp the second sub-component 26 and hold the second sub-component 26 during the assembly process. The third end of arm tool 22 is adapted to grasp the third sub-assembly 28 and hold the third sub-assembly 28 during the assembly process.

By way of non-limiting example, the first, second and third subcomponents 24, 26, 28 may be panels configured as decklids or lift gates of automobiles. Alternatively, the first, second, and third subcomponents 24, 26, 28 may be aircraft fuselage panels, door panels of consumer appliances, chair armrests, or any other subcomponent configured to engage or attach to another subcomponent. The first, second and third subcomponents 24, 26, 28 may be formed of any suitable material, such as metal, plastic, composite material, and the like. As shown in the exemplary embodiment of FIG. 1, the first, second and third subcomponents 24, 26, 28 are frame components of an automobile.

The first, second and third robotic arms 12, 16, 20 may be programmable robotic arms, may include hands, wrists, elbows and shoulders (not shown), and may be remotely controlled by pneumatic and/or electronic means. By way of non-limiting example, the first, second and third robotic arms 12, 16, 20 may be six-axis articulated robotic arms, cartesian robotic arms, spherical or polar robotic arms, selectively compliant assembly robotic arms, or the like. In one non-limiting example, the first, second, and third robotic arms 12, 16, 20 may be six-axis articulated robotic arms.

The system controller 30 is adapted to control the first, second and third robotic arms 12, 16, 20 and the first, second and third end-of-arm tools 14, 18, 22. The system controller 30 is a non-generalized electronic control device having a preprogrammed digital computer or processor, a memory or non-transitory computer readable medium for storing data, such as control logic, software applications, instructions, computer code, data, look-up tables, or the like, and a transceiver or input/output port. A computer-readable medium includes any type of medium capable of being accessed by a computer, such as Read Only Memory (ROM), Random Access Memory (RAM), a hard disk drive, a Compact Disc (CD), a Digital Video Disc (DVD), or any other type of memory. A "non-transitory" computer-readable medium does not include a wired, wireless, optical, or other communication link that conveys transitory electrical or other signals. Non-transitory computer readable media include media that can permanently store data and media that can store and later rewrite data, such as rewritable optical disks or erasable memory devices. Computer code includes any type of program code, including source code, object code, and executable code.

The system controller 30 moves the first, second and third robotic arms 12, 16, 20 and actuates the first, second and third end-of-arm tools 14, 18, 22 to bring the first, second and third end-of-arm tools 14, 18, 22 into position for grasping the first, second and third sub-components 24, 26, 28 and to bring the first, second and third end-of-arm tools 14, 18, 22 into position for properly positioning the first, second and third sub-components 24, 26, 28 relative to each other. The system controller 30 moves the first, second and third robotic arms 12, 16, 20 based on executable code stored in memory or provided to the system controller 30.

The clampless component assembly system 10 includes at least one inspection camera 32. The inspection camera visually locates the interface surfaces 34, fiducials, and identification features of the first, second, and third sub-components 24, 26, 28. The inspection camera 32 communicates with the system controller 30. The system controller 30 uses information from the inspection cameras to determine the position of the first, second and third sub-assemblies 24, 26, 28 relative to each other and to control the first, second and third robotic arms 12, 16, 20 to move the first, second and third sub-assemblies 24, 26, 28 appropriately throughout the assembly process. Inspection cameras 32 may be mounted at fixed locations within the system. Alternatively, the inspection camera 32 may be mounted to an inspection robot arm, wherein the system controller 30 moves the inspection camera 32 to various positions relative to the first, second and third sub-assemblies 24, 26, 28.

A first load cell 36 is mounted on the first end of arm tooling 14 and is adapted to measure torsional and lateral forces exerted by the first end of arm tooling 14 on the first sub-assembly 24. A second load cell 38 is mounted on the second end-of-arm tool 18 and is adapted to measure torsional and lateral forces exerted by the second end-of-arm tool 18 on the second sub-assembly 26. A third load cell 40 is mounted on third arm end tool 22 and is adapted to measure torsional and lateral forces exerted by third arm end tool 22 on third sub 28.

The first, second and third robotic arms 12, 16, 20 are adapted to be controlled by the system controller 30 based on position control or force control. When the system controller 30 is using position control, the first, second, and third robot arms 12, 16, 20 are controlled based on the three-dimensional positions of the first, second, and third robot arms 12, 16, 20 within the workspace of the component assembly system 10. When position control is used, the first, second and third robot arms 12, 16, 20 are controlled to maintain them in a particular position. When the system controller 30 uses force control, the first, second and third robot arms 12, 16, 20 are controlled based on force feedback measured by the first, second and third load cells 36, 38, 40.

The first, second and third load cells 36, 38, 40 send feedback to the system controller 30 when the first, second and third subcomponents 24, 26, 28 are preassembled. The system controller 30 uses the information from the first, second and third load cells 36, 38, 40 to determine when the first, second and third subcomponents 24, 26, 28 are properly preassembled. In the exemplary embodiment shown in FIG. 1, the first, second and third subcomponents 24, 26, 28 are engaged with one another by a slip-fit engagement. Portions of the second sub-member 26 slide into the receiving portions 42 of the first and third sub-members 24, 28 in a slip fit engagement. The friction of the slip fit engagement is measured by the first, second and third load cells 36, 38, 40 as the first, second and third subcomponents 24, 26, 28 are engaged. The system controller 30 uses force control and information from the first, second and third force gauges 36, 38, 40 to move the first, second and third robotic arms 12, 16, 20 and, based on the force measurements, force the first, second and third subcomponents 24, 26, 28 into spaced-apart mating engagement with one another until the first, second and third subcomponents 24, 26, 28 are fully engaged.

Furthermore, it may be desirable to introduce a preload on the first, second, and third sub-members 24, 26, 28 to counteract the expected thermal deformation during welding. The welding of the first, second and third sub-members 24, 26, 28 will cause thermal expansion and deformation of the first, second and third sub-members 24, 26, 28. To overcome this, the first, second, and third robotic arms 12, 16, 20 may exert additional torsional and lateral forces on the first, second, and third sub-members 24, 26, 28 before welding begins. For example, it may be desirable to introduce a preload or bend in the preassembled first, second and third sub-members 24, 26, 28 prior to welding. Bending without plastic deformation will create a preload in the finished part. When the weld is completed and the finished component is removed, the finished component will react in a predictable manner to the newly formed weld between the first, second and third sub-components 24, 26, 28.

During the welding process, the system controller 30 may be used to vary the torsional and lateral forces applied to the first, second, and third subcomponents 24, 26, 28. In this manner, the forces applied to the first, second and third sub-members 24, 26, 28 may be carefully controlled in response to thermal expansion, thermal deformation or other reactions to the welding process as the welding process progresses. Finally, when welding the first, second and third sub-members 24, 26, 28 together, controlling the position of the first, second and third sub-members 24, 26, 28 relative to each other and controlling the forces applied to the first, second and third sub-members 24, 26, 28 allows for control of the final shape and material properties of the finished component.

The joining robot arm 44 includes a joining tool 46 mounted thereon. The engagement tool 46 is adapted to engage the first, second and third subcomponents 24, 26, 28. The joining robot arm 44 is controlled by the system controller 30 to engage the joining tool 46 with the first, second, and third subcomponents 24, 26, 28. The joining robot arm 44 may be a programmable robotic arm, may include a hand, a wrist, an elbow, and a shoulder (not shown), and may be remotely controlled by pneumatic and/or electronic means. By way of non-limiting example, the jointed robotic arm 44 may be a six-axis articulated robotic arm, a cartesian robotic arm, a spherical or polar robotic arm, a selectively compliant assembly robotic arm, or the like. In one non-limiting example, the jointed robotic arm 30 may be a six-axis articulated robotic arm.

It should be understood that the bonding tool 46 may be any type of bonding tool suitable for bonding sub-components of different materials and properties. In the exemplary embodiment shown in fig. 1, the joining tool 46 is a welding tool adapted to form weld attachments for the first, second, and third subcomponents 24, 26, 28. Further, a plurality of joining robot arms 44 may be used. In the exemplary embodiment shown in FIG. 1, the clampless component assembly system includes three substantially identical joining robot arms 44, with joining tools 46 mounted on the joining robot arms 44 to join the first, second, and third subcomponents at different locations.

Referring to fig. 2, a method of assembling components is generally shown at 50. The method of assembling a finished component using the component assembly system 10 includes grasping 52 the first sub-component 24 with the first end-of-arm tool 14, grasping 52 the second sub-component 26 with the second end-of-arm tool 18, and grasping 52 the third sub-component 28 with the third end-of-arm tool 22. After grasping 52 the first, second and third sub-assemblies 24, 26, 28, the first, second and third robotic arms 12, 16, 20 move 54 the first, second and third end-of-arm tools 14, 18, 22 to a pre-assembly position. In the pre-assembly position, the first, second and third subcomponents 24, 26, 28 are in close proximity to each other, but are not engaged with each other.

After the first, second and third subcomponents 24, 26, 28 are brought to the pre-assembly position, the inspection camera 32 visually positions 56 the interface surfaces 34 of the first, second and third subcomponents 24, 26, 28. The inspection camera 32 communicates with the system controller 30. The system controller 30 uses the position of the interface surface 34 to estimate 58 an offset between the pre-assembly position and the desired assembly position. This estimate allows the system controller 30 to determine the movement that needs to be made to further engage the first, second and third subcomponents 24, 26, 28.

After estimating the offset, the system controller articulates the first, second, and third robotic arms 12, 16, 20 to move 60 the first and second end-of-arm tools 14, 18, 22 to engage the interface surfaces 34 of the first, second, and third subcomponents 24, 26, 28. The first, second and third load cells 36, 38, 40 send feedback to the system controller 30 when the interface surfaces 34 of the first, second and third subcomponents 24, 26, 28 are engaged. The system controller 30 moves 62 the first, second and third subassemblies 24, 26, 28 to the desired assembly position. The first, second and third load cells 36, 38, 40 measure 64 the torsional and lateral forces exerted on the first, second and third subcomponents 24, 26, 28 as the first, second and third subcomponents are moving toward the desired assembly position. The system controller 30 uses the information from the first, second and third load cells 36, 38, 40 to determine when the first, second and third subcomponents 24, 26, 28 are properly positioned at the desired assembly location.

In the exemplary embodiment shown in FIG. 1, the first, second and third subcomponents 24, 26, 28 are engaged with one another by a slip-fit engagement. Portions of the second sub-assembly 26 slide into the receiving portions 42 of the first and third sub-assemblies 24, 28 in a slip fit engagement. Upon engaging the first, second and third subcomponents 24, 26, 28, the frictional force of the slip-fit engagement is measured by the first, second and third load cells 36, 38, 40. The system controller 30 uses force control and information from the first, second and third force gauges 36, 38, 40 to move the first, second and third robotic arms 12, 16, 20 and, based on the force measurements, force the first, second and third subcomponents 24, 26, 28 into spaced-apart mating engagement with one another until the first, second and third subcomponents 24, 26, 28 are fully engaged.

When the system controller 30 determines that the first, second and third subassemblies 24, 26, 28 are properly positioned at the desired assembly positions, the inspection camera 32 scans 66 the first, second and third subassemblies 24, 26, 28 to visually locate assembly fiducials on the first, second and third subassemblies 24, 26, 28. The system controller 30 will use the information from the inspection camera 32 to compare 68 the scanned positions of the first, second and third subassemblies 24, 26, 28 to the desired assembly positions and verify that the first, second and third subassemblies 24, 26, 28 are positioned within the desired assembly positions within acceptable tolerances.

If the system controller 30 determines that the first, second and third sub-assemblies 24, 26, 28 are not properly located at the desired assembly positions, the first, second and third robotic arms 12, 16, 20 will make adjustments and move 70 the first, second and third sub-assemblies 24, 26, 28 to the desired assembly positions within the established tolerance.

Furthermore, it may be desirable to introduce a preload on the first, second, and third sub-members 24, 26, 28 to counteract the expected thermal deformation during welding. The welding of the first, second and third sub-members 24, 26, 28 will cause thermal expansion and deformation of the first, second and third sub-members 24, 26, 28. To overcome this, the first, second and third robotic arms 12, 16, 20 may apply additional torsional and lateral forces to the first, second and third sub-members 24, 26, 28 and move 72 the first, second and third sub-members 24, 26, 28 to the thermal deformation compensation position before welding begins. For example, it may be desirable to introduce a preload or bend in the preassembled first, second and third sub-members 24, 26, 28 prior to welding. Bending without plastic deformation will create a preload in the finished part. When the weld is completed and the finished component is removed, the finished component will react in a predictable manner to the newly formed weld between the first, second and third sub-components 24, 26, 28.

After the system controller 30 moves the first, second, and third subcomponents 24, 26, 28 to the desired assembly position or possibly thermal distortion compensation position, a bonding tool 46 attached to the bonding robot arm 44 is used to form 74 a bond between the first subcomponent 24 and the second subcomponent 26. Further, a joint is formed 74 between the second and third subcomponents 26, 28 using the joining tool 46 attached to the joining robotic arm 44.

It should be understood that the bonding tool 46 may be any type of bonding tool suitable for bonding sub-components of different materials and properties. In the exemplary embodiment shown in fig. 1, the joining tool 46 is a welding tool adapted to form weld attachments for the first, second, and third subcomponents 24, 26, 28. Further, a plurality of joining robot arms 44 may be used. In the exemplary embodiment shown in FIG. 1, the clampless component assembly system includes three substantially identical joining robot arms 44, with joining tools 46 mounted on the joining robot arms 44 to join the first, second, and third subcomponents at different locations.

During the welding 74 of the first, second, and third subcomponents 24, 26, 28, the system controller 30 may vary the amount of force applied by each of the first, second, and third robotic arms 12, 16, 20 to the first, second, and third subcomponents 24, 26, 28 during the entire formation 74 of the joint.

After the first, second, and third sub-components 24, 26, 28 are welded together, the inspection camera scans 76 the finished component to verify the final geometry of the finished component. Prior to scanning 76, the system controller will allow the first, second and third robotic arms 12, 16, 20 to remove any forces applied to the first, second and third sub-assemblies 24, 26, 28. The system controller 30 will verify that the finished part has the proper geometry. If the geometry of the finished part needs to be adjusted, the system controller 30 may articulate the first, second, and third robotic arms 12, 16, 20 to generate forces on the finished part to plastically deform 78 the finished part.

The component assembly system 10 of the present disclosure provides several advantages. The sub-components can be assembled without using a special jig. In addition, the sub-components 16, 22 may be subjected to external forces before and during the welding process to produce predictable thermal deformation and material properties. Finally, the component assembly system 10 of the present disclosure may perform as described above and is flexible to accommodate different types of components and to change the characteristics of the components formed therein.

The description of the disclosure is merely exemplary in nature and variations that do not depart from the gist of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.