carat robotic Uses PTC’s GRANITE Kernel to Create
New, Lower-Cost Sheet Metal Forming Solution Using Robots
Through PTC’s Partner Advantage Program, Software Developers such as carat robotic
Can License PTC’s GRANITE to Add Robust Interoperability to their Software Applications
carat robotic innovation GmbH, Dortmund, Germany carat robotic is a leading developer of software for the offline programming, setting up, and movement of industrial robots. The company also provides expertise in the area of robot systems for grinding, polishing and milling of complex freeform surfaces, as well as special applications
with integrated measuring technology.
carat robotic is known globally for its FAMOS robotic(R) software which enables the quick and efficient programming of industrial robots, including all aspects of the process application. carat’s FAMOS robotic software is installed at manufacturing companies worldwide in indus- tries ranging from automotive to cosmetics.
The Challenge: Two Robots ‘Collaborating’ to Create Sheet Metal Forms
Traditional sheet metal forming, using conventional die and mold-forming parts, can be very expensive, especially for prototypes and limited-lot runs, where you need to replace the mold for each part you design and build. Recently, carat robotic set out on an R&D project –entitled “Roboforming” – with a select group of German universities and manufacturers to develop a more efficient process, where two robots – programmed to communicate with each other – would work to create a sheet metal part for prototypes and limited-lot runs.
The Solution: carat robotic– Using PTC’s GRANITE Kernel – Provides Software for the Solution
A critical first step in the Roboforming project was to import multiple 3D CAD files from different CAD software packages into carat’s FAMOS robotic software system. To get started, a reliable interoperability kernel was needed that could support a wide range of 3D CAD file formats. As a member of PTC’s Partner Advantage Program, carat robotic was able to integrate PTC’s GRANITE interoperability kernal into its FAMOS robotic software. As a result, FAMOS robotic can easily and efficiently read 3D CAD files created using STEP, IGES and a range of other file for-mats supported by GRANITE, including ACIS and Parasolid, as well as PTC's Pro/ENGINEER integrated 3D CAD/CAM/CAE solution and PTC's ProductView visual collaboration software.
Above: An example of a virtual robot cell in carat robotic’s industrial robot software, FAMOS robotic.
Results: Faster, Easier, Less-expensive Sheet Metal Forming
The first Roboforming plant is now set up at LPS Ruhr-University in Bochum, Germany. Engineers at carat robotic predict that, in the future, this procedure will become one of the major methods of sheet metal production for prototype and limited-runs. “This method is lower-cost and quicker because you don’t need to produce the mold or the die, you just have to program the part,” said Timm Hoffman,Project Engineer at carat robotic. “Each part you produce, you start saving money. With traditional deep-drawing processes, each new part, even for a prototype, may cost thousands of Euros. Having robots create the part eliminates that cost.”
“The benefit of GRANITE is we can import different file formats, and the analysis functions work efficiently because of the easy accessibility to the interfaces of the kernel. You don’t have to program a lot to access the functions. By analyzing the surfaces, we are able to create the points to plot the paths for the robots.” – Timm Hoffman, Project Engineer at carat robotic
Case Study
Partnering with PTC Pays Off
In 2001, carat robotic innovation GmbH partnered with PTC – the leading CAD/CAM/CAE and Product Lifecycle Management (PLM) provider – to integrate PTC’s GRANITE interoperability kernel into its FAMOS robotic software. GRANITE is ideal for companies looking for easy access to model content from a diverse range of fle formats, or for a best-in-class, feature-based modeling engine. GRANITE is available to commercial software vendors and end-user software development teams through PTC’s Partner Advantage Program, which provides partners with the resources needed to solve their customer’s complex challenges.
Since FAMOS robotic software makes it easier to program a robot using 3D CAD data, carat robotic now relies on GRANITE – integrated within its own application – to effciently read CAD fles into its soft-ware using STEP, IGES and a range of other fle formats supported
by GRANITE.
“Concerning the interoperability and the analyzing functions needed, the choice was clearly made for GRANITE,” said Timm Hoffman, Pro-ject Engineer at carat robotic. “Complex virtual set-ups can be realized with the customer´s data, even if provided in various fle formats.”
Simulation of the supporting and forming tool along the trajectories.
Forming the Future of Sheet MetalRecently, carat robotic teamed with several universities and manufac-turing companies in Germany, as well as with the German Industrial Association for Sheet Metal Forming, to develop a more effcient process for forming sheet metal parts for prototypes and small-lot runs using cooperating robots, where two robots – programmed to
communicate together via a TCP/IP connection – could work on the same part.
The goal was to solve an age-old problem: traditional sheet metal forming using conventional die and mold forming parts was expen-sive due to prototypes and limited-lot runs caused by the need to
replace the mold for every part designed and built. These costs only increase with more complex sheet metal designs.
The R&D project, named Roboforming, was to develop a robot-based sheet metal forming process for the production of sheet metal com-ponents. The Roboforming system consists of two robots, controllers, plant components such as a clamping frame to hold the sheet metal, a set of tools for shaping the sheet metal, and software.
The generation of the sheet metal’s shape is implemented by means of two industrial robots; one robot drives the forming, the other drives the supporting tool. The fnal shape is produced by the incremental in-feed of the forming tool’s in-depth direction, and its movement along the contour in a lateral direction on each level, while the sheet is sustained by the supporting tool on the opposite side. Compared to other sheet metal forming machines, this system offers high
geometrical form fexibility without the need for any work-piece dependent tools.
“This method is lower cost and quicker because you don’t need to produce the mold or the die, you just have to program the part,” said Hoffman, who leads carat’s participation in the Roboforming project. “If geometry changes, you don’t have to redo the die. With
this new process you just have to buy one set of tools, along with the Roboforming system, and then you can make whatever geometry you want. Each part you produce, you start saving money. With traditional deep-drawing processes, each new part, even for a prototype, may cost thousands of Euros. Having robots create the part elimi-nates that cost,” stated Hoffman.
The project, which is expected to lead to commercial applications in automotive and other industries, was initiated by LPS Ruhr-University in Bochum, Germany, in cooperation with IRF University in Dortmund, Germany. In addition to carat, other contributors are
Dieffenbacher GmbH in the feld of automation solutions, Steinbichler Optotechnik GmbH in the feld of optical sensor systems, and KUKA Roboter GmbH in the feld of industrial robots. Participating manufacturing companies include BMW Fahrzeugtechnik GmbH and HMT
GmbH and Co. in the automotive industry, and Seidel GmbH & Co. in the design parts industry.
First Things First: Bringing CAD Files into the System
Importing of CAD fles into the software system is a critical frst step. A reliable interoperability kernel was needed to support a wide range of supported fle formats. Using GRANITE, all common formats can be imported and handled, which was clearly demonstrated during initial tests of fles provided by users within the project. Users had their own CAD software with its specifc export format. The most common interchange formats – STEP, IGS and VDA/FS – were tested to defne the best exchange format. All data has been handled well by GRANITE within the FAMOS application.
In Roboforming, the robot has to move the forming tool along spiral trajectories on the model’s surface to achieve the desired form. In order to provide an exact movement, the robot needs the coordinates and the orientation given by points which are put together into trajectories. These trajectories are generated by a plug-in developed within the offine-programming system. Because the models often consist of freeform surfaces, functions are needed to analyze the curvature of the model.
GRANITE provides the functions required: the model is intersected by planes oriented in a defned way to fnd interpolation points for the trajectory-generation (see below). The trajectory then runs right on the surface. Adjustments, such as the offset by the radius of the tool or other corrections, can be applied afterwards. Different shapes, even within one part, need different forming strategies, which are defned by the position and movement of the forming tool relative to the supporting tool. The shapes differ in steepness, radius and orientation of the curvature, so they have to be selectable to be able to assign the best strategy for positioning the forming tool relative to the supporting tool. GRANITE gives FAMOS robotic access to the structure of the CAD model, whether it is a whole assembly, parts of an assembly, or just single surfaces of a part.
Supporting planes for the preparation of paths.
The generated paths for the forming and the supporting tool are compiled by FAMOS robotic into programs for both robots, which can be transferred directly to the robot controllers. With the robot design cell set up beforehand using the FAMOS robotic virtual reality environment and calibrated with the real environment, the programs can then be immediately executed. The robots then form the metal sheet into the desired shape (see below).
Forming of sheet metal by two cooperating robots.
Roboforming plant at the LPS Ruhr-University, Bochum, Germany.
“The main problem in developing the software is the complex trajectories for the forming tools,” said Hoffman. “There are so many points to describe the geometry that we needed to create software to describe all these points. There was no system to program cooperating robots; now
we can program cooperating robots.”
A frst example of a Roboforming plant has been set up at LPS RuhrUniversity (see image above). An additional plant is being built at IRF University in Dortmund.
“Ruhr University initiated this project originally for research,” explained Hoffmann. “They thought it would be a good idea to use cooperating robots as a means to form geometries more easily for limited-lot productions. And there was a need from industry to have a method to form sheet metal in this way.”
In the future, Hoffmann predicts this procedure will be one of the major methods of sheet metal production for prototype and limited-runs used to produce everything from the gas tank of an automobile, to the covers of a cosmetics case.