sam sokolik wrote: > I think a larger read-ahead is the priority. > Yes, there are only two ways to deal with this. The safe way requires the interpreter to sanitize the tool path before handing it to the trajectory planner, so there will be no surprises while moving at high velocity.
The other way is to assume the CAM system never generates code the machine can't follow, and if it occurs, then you have a massive velocity discontinuity. This might make some people quite happy, as they could do high speed contouring that you can't do now with LinuxCNC. But, of course, it is a bit dangerous, the "trust me, I know what I'm doing" mode of operation. The problem with the "larger read-ahead" is that there is no best choice for how much read-ahead you need, and doing it in real time gets pretty complicated. It is conceivable that you could need 1000 blocks of read ahead in some contouring programs, and I don't think you can have the TP do this for every line and arc segment. My naive scheme was to have a big buffer of the trajectory moves, and when you hit a part that required slowing down, you could then work backwards to figure out when you needed to begin the slowing down. There would be a velocity for each move, and this working backwards scheme would edit those velocities down to accommodate the need for acceleration in the future. Not sure if this makes sense, but that was what seemed to be the mechanism that made the problem tractable to me. Jon ------------------------------------------------------------------------------ LIMITED TIME SALE - Full Year of Microsoft Training For Just $49.99! 1,500+ hours of tutorials including VisualStudio 2012, Windows 8, SharePoint 2013, SQL 2012, MVC 4, more. BEST VALUE: New Multi-Library Power Pack includes Mobile, Cloud, Java, and UX Design. Lowest price ever! Ends 9/20/13. http://pubads.g.doubleclick.net/gampad/clk?id=58041151&iu=/4140/ostg.clktrk _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
