Siemens is introducing a fundamentally new way to create mechanical designs with 3-D solids modeling technology. Called synchronous technology, it combines the best of constraint-driven techniques (think parametric modeling) with direct modeling, according to Siemens.
Its synchronous technology promises faster capture of ideas, faster design changes, and improved reuse of CAD from multiple formats. The interaction paradigm merges historically independent 2-D and 3-D environments, providing the robustness of a mature 3-D modeler with the ease of 2-D, according to Siemens. A technique called suggestive selection automatically infers the function of various design elements without the need for feature or constraint definitions. This is said to increase design reuse and OEM/supplier efficiency.
A bottleneck with parametric technology is the need to retain a history of how the part was built while maintaining the sometimes complicated constraint relationships. Making changes to a detailed part or assembly with a substantial history list can be computationally tedious. It can also be difficult for someone other than the original author to understand the history of design actions. According to Siemens, synchronous technology recognizes in real time where constraint conditions exist and localizes rebuilding the model only where needed to maintain geometric constraints. Siemens describes it as simultaneously synchronizing geometry and rules through a new decision-making inference engine.
“This is technology that for the first time is integrated well in a mainstream CAD solution,” said John MacKrell, Senior Consultant with CIMData who has more than 30 years' experience in the CAD industry, noting that other CAD systems have done parts of this in the past. “The purpose is not to do away with the parametric method but augment it. The synchronous method requires no history of how the original part was built. Freedom from old history trees frees people from issues with changing older models.”
"The ability to grab a design from a foreign CAD system and instantiate that feature and use it over and over again is a key element,” said MacKrell, “This opens the door for multiple CAD use. It allows an NX user to import anything that is represented as a solid model feature, from any other CAD system" including those from Dassault or PTC.
It should make engineers' and CAD designers' jobs easier, if it works as designed, comments Marc Halpern, Research Director for Gartner. “The net effect for automotive engineering is that the CAD operator [either designer or engineer] should be spending less time on the gymnastics of editing CAD models and more time on actual design issues.” Besides making changes easier, he believes two more key points will make a synchronous system more productive for a typical automotive firm. Because it is easier to use, the learning curve for new engineers will decrease dramatically. Also, the computational time to execute changes will decrease, making it more productive in use.
Halpern is optimistic about the technology and notes that there are no fundamental changes in mathematics behind the geometry in this CAD and earlier generations. He also offers some cautions to companies considering adoption. “There is no question that this is where the industry is headed,” he said. “There is also no question that it will affect a CAD department’s modeling guidelines. In addition, this technology will have its own idiosyncrasies compared to today’s technology. It will behave differently. A company will need to understand that different behavior before adopting it widely. Finally, there may be bugs, which need to be discovered.” He believes a carefully conducted pilot program will provide insight for a company to guide its way through a transition.
This synchronous technology is integrated into Siemens PLM’s next versions of NX and Solid Edge software.How this works with surface modelers—a key element for the automotive market—seems to be an open question at the moment. According to Siemens, synchronous technology works with a large percentage of the "zero-thickness" sheet metal use cases it has tested. It is, however, an area of intense case study development for coming releases.