30 years ago. Computer Aided Design, or CAD – what’s that for? Stupid question, I know. But when the first CAD software came in early 80’s that was the time of drawing boards and “rotring rapidos”, marker pens. No true designer would ever have used a software which takes away all imagination and innovation spirit. “And CAD is difficult to use by the way”, they said.
Picture. Australia’s Professional Engineer of the Year, Mr. Stuart Payne. Courtesy: Engineering News “How engineering has changed over three decades” by Justin McGar, 2014.
In 2016. “A rapido” – what’s that for. A stupid question again. Everybody uses CAD. Only an old architect might use markers. The same story goes with CAM software. Only few people question these days the use of Computer Aided Manufacturing. Nowadays CAM goes hand in hand with CNC machines.
CIM AND INDUSTRY 4.0
Computer Integrated Manufacturing, CIM, in 80’s had a lot of similarities to present Industry 4.0. The difference is that CIM was an engineering “fantasy”, but Industry 4.0 is already a working concept. The ability to integrate product design with manufacturing engineering and finally down to the working robots on the shop floor brings the true value to the business. Importance of integration has been realized for a long time with machining and is emerging extensively also in robotics. When a same company is already using CAM with CNC machines why would they not use offline programming for their robots. Robot offline programming is in fact CAM. It is CAD-based programming where the software takes the full advantage of the features and meta-data of a CAD model.
HOW DOES CAD-BASED PROGRAMMING WORK?
In a modern offline programming software a programmer does not write a single line of robot programming code – not a line.
- He/she points out a CAD feature, like an edge between two plates with just one or two mouse clicks, and the software automatically generates a welding path with approach, search, welding and departure points. This all might take some seconds.
- Then programmer simulates the program for reachability, joint violations, and collisions/near-misses.
- When the program is verified, programmer presses a button “down load”. This will start a postprocessor program. Postprocessor scripts a native robot program, e.g. for KUKA, automatically in right syntax.
- A native robot program file is then saved on a computer for use on the shop floor with actual robot. This all took a few minutes.
VALUE OF CAD
Offline programming would not be possible without CAD. Value of CAD is not only in design but also in integration with CAM software. CAD data contains so much data available when programming offline NC machines or robots. Utilizing effectively CAD features, like holes, edges, B-splines, mathematical surfaces, material characteristics etc. makes programming pretty much automated. It would be waste of time and money not to benefit of rich CAD data. A plotted CAD drawing makes no sense.
Heikki Aalto, 3.4.2016