Patent Application
20230126307
The disclosure relates to punching and/or welding operations to parts such as bumper facias.
Bumper facias are constructed from a flexible plastic having complex compound curves. Typical modern bumper facia has multiple holes punched in it to accommodate ultrasonic parking sensors and the like. Holes may be punched for other purposes as well. Various brackets are secured to a B-side of the facia by ultrasonic welding to support the sensors and other components. The intended hole locations are typical identified with markings on the B-side, such as a raised symbol, corresponding to the target for the punch. The punch must accurately shear the hole at the target to produce a quality bumper facia.
Conventional bumper facia punching and/or welding equipment is relative expensive. This is in part due to the dedicated bumper facia nests that must be built for each bumper facia and the attendant dedicating tooling for that particular bumper facia.
In operation, an operator loads a bumper into the dedicated nest, where the bumper remains stationary throughout the punching and/or welding operations. Dedicated punching and/or welding tools are provided for each location or groups of locations where an operation must occur. This requires multiple punches and/or multiple welders for every bumper. When equipment for a new bumper facia is needed, for example, at a vehicle model changeover, the entire nest and tools must be reconfigured and rebuilt.
There have been attempts to provide a more flexible robotic punching cell, but those attempts have failed because the hole locations could not be located accurately enough. A multi-axis robot was used to hold the bumper and present the various hole locations to a common punching tool. A 2D sensor with a camera and a light were provided at the punching tool. The light was positioned to shine on the target, and the 2D sensor identified the target as an x,y coordinate only and provided an offset to the robot so that it could accurately locate the bumper facie with respect to the punching tool. Nonetheless, this system did not result in an accurately located hole precisely at the target. That is, the target was not properly identified.
In one exemplary embodiment, a system for performing an operation on a part, includes a first fixture that is configured to support one side of a part, a robot that has a second fixture that is configured to support an opposite side of the part with respect to the one side. One of the part sides has a target on a surface that indicates a location for the operation. The system further includes a sensor that is configured to measure the target in 3-dimensional space, a tool that is configured to perform the operation at the location, and a controller that is configured to move the robot to pick up the part from the first fixture using the second fixture. The controller is configured to present the target to the sensor for measuring the x,y,z coordinates and the yaw, pitch and roll of the target, and the controller is configured to move the second fixture with the part to the tool based upon the measurement.
In a further embodiment of any of the above, the one side is a B-side of the part, the opposite side is the A-side of the part, and the target is located on the B-side.
In a further embodiment of any of the above, the first fixture includes multiple guide brackets that are configured to cooperate with a perimeter of the part to guide the part onto support structure. The support structure is arranged beneath the target.
In a further embodiment of any of the above, the second fixture includes suction cups that are configured to selectively attach to the A-side.
In a further embodiment of any of the above, the sensor is arranged in proximity to a base of the robot.
In a further embodiment of any of the above, the sensor includes a camera and multiple lights that are arranged at different angles in relation to the target.
In a further embodiment of any of the above, the target includes a pattern that is raised with respect to an immediately adjacent surface.
In a further embodiment of any of the above, the pattern is cross-hairs that indicate the location.
In a further embodiment of any of the above, the controller is configured to present the part to the tool at an orientation that corresponds to the yaw, pitch and roll of the target.
In a further embodiment of any of the above, the part includes multiple targets each having different curved surfaces with different characteristics.
In a further embodiment of any of the above, the controller is configured to present each of the targets to the sensor for measurement of the characteristics.
In a further embodiment of any of the above, the controller is configured to present the multiple targets to the tool for performing the operation.
In a further embodiment of any of the above, the tool is one of a punching tool and a welding tool.
In a further embodiment of any of the above, the sensor includes a camera.
In a further embodiment of any of the above, the part is a bumper facia.
In another exemplary embodiment, a method of performing an operation on a part, includes supporting a part in a first fixture, robotically picking up the part with a second fixture, and measuring a target on a curved surface of the part to determine a location of the target in 3-dimensional space. The target measuring step includes determining the x,y,z coordinates and the yaw, pitch and roll of the target. The method further includes presenting the part to a tool at an orientation that corresponds to the measured location of the target, and performing an operation at the location.
In a further embodiment of any of the above, the robotically picking step includes suctioning a side of the part opposite the side with the target.
In a further embodiment of any of the above, the measuring step includes robotically presenting the target to a camera.
In a further embodiment of any of the above, part has multiple targets, and the measuring step includes presenting the multiple targets to the camera. The performing step includes performing the operation and the location corresponds to each of the multiple targets.
In a further embodiment of any of the above, the operation is one of punching or welding.
The disclosure can be further understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible. Like reference numbers and designations in the various drawings indicate like elements.
A system for a cell 10 is configured to perform an operation on a part 22, such as a bumper facia or other component (e.g., plastic component), is shown in
A first fixture 12 is provided in the cell to support one side of the part (e.g., facia) 22, for example, the B-side 38 (
The cell 10 also includes a multi-axis robot 16 supported on a pedestal 17 and having a second fixture 14 mounted to an end effector, as shown in
The first and second fixtures 12, 14 are made of relatively inexpensive, reconfigurable structural elements to create a framework for supporting the part 22. The supporting structures (e.g., guide brackets 34, stops 45, locating brackets 44, suction cups 42) can be easily moved about by providing different supporting flanges and/or by sliding the supporting structures in longitudinal slots in the structural elements to different positions. In the example, the stops on the first and second fixtures 12, 14 include surfaces shaped to match the contour of the part 22 adjacent to a location of a target 46 on the part 22 (
One of the part sides (e.g., B-side 38) has a target 46 (
A sensor 32, such as a circumferential array of lights 32a surrounding a camera 32b, is mounted to the pedestal 17 in proximity to a base of the robot 16, for example. The sensor 32 is used to measure the various targets 46 on the part 22. In one example, the camera is manufactured by Keyence (e.g., series CV-X/XG) and provides a 3-dimensional vision system capable of not only identifying the x,y,z coordinates of the target 46 and but also its orientation (via cross-hairs, for example) based upon the contour of the underlying surface (the yaw, pitch, roll of the target 46). However, it should be understood that any suitable pattern may be used for the target 46. Said another way, the target 46 needs to be found in three dimensions (x,y,z; yaw, pitch, roll) in order to align the tool to the proper tool reaction orientation, (or in the case of punching in the proper draft angle of the punch) because almost always the parts are not flat.
Referring to
The target 46 is arranged on a curved surface and includes a pattern. The sensor 32 is configured to measure characteristics of the curved surface using the target 46. In one example, the pattern is raised (e.g., 0.5 mm) with respect to an immediately adjacent surface. In the example, the pattern is cross-hairs indicating the precise x,y,z location in 3-dimensional space for the operation. By measuring each target within three dimensions, including z and its yaw, pitch, roll, this allows for a calculation of the precise location on the target 46 within the cell's workspace in order to place the part 22 in the gripper to the robot 16 to be presented to another potential tool (in this case a punch 20) to do a high precision action in three dimensions. Each individual “targeting process” results in a different calculation to perform an action, i.e., even though there is one part, each target is treated as its own function.
In one example, in order to provide sufficiently accurate identification of the target, the sensor 32 includes an array of light sources 32a oriented at different angles that permits the various surfaces of the target 46 to be better illuminated for the camera 32b. A grid pattern may also be shined upon the target using the lights 32a, which better reveals the 3D contours of the target 46 on the compound curvature of the part. Since the lights 32a project a grid pattern at different angles with a single camera capturing them, a highly accurate 3D image can be made, giving x,y,z and yaw, pitch, and roll in the workspace.
The target image capturing approach described above enables the sensor to concentrate on a smaller area of the part in order to identify the target, which reduces cycle time. That is, much more contour data was required, which still provided poor results. Other image capturing approach uses 2D technology that has proven inaccurate, because it will not give x,y,z, yaw, pitch and roll of the part location, and this technology is highly influenced by ambient light. Other 3D scanning technology attempted, requires a larger area to determine part contours to calculate part location in 3D relative to Robot universal coordinates, thus estimating target location, however this process requires a large area to be scanned and has not proved to be reliable. In addition, these parts tend to be manufactured in a material (very flexible plastic) susceptible to inconsistency in tolerance due to factors such as humidity and heat, adding to the lack of reliability.
The controller is configured to command the robot 16 to present the part 22 to the tool (e.g. punch 18 or welder 20) at x,y,z and an orientation (yaw, pitch, roll) corresponding to the characteristics of the curved surface. Typically, the part 22 includes multiple targets each having different curved surfaces with different characteristics (e.g., multiple ultrasonic parking sensor locations on a bumper facia). The tool is configured to perform the operation at the location.
It should also be understood that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit herefrom. Although particular step sequences are shown, described, and claimed, it should be understood that steps may be performed in any order, separated or combined unless otherwise indicated and will still benefit from the present invention.
Although the different examples have specific components shown in the illustrations, embodiments of this invention are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples.
Although an example embodiment has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of the claims. For that reason, the following claims should be studied to determine their true scope and content.
This application claims priority to U.S. Provisional Application No. 63/270,830 filed on Oct. 22, 2021, and is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63270830 | Oct 2021 | US |
