2013/12/26 Chris Radek <[email protected]> > On Thu, Dec 26, 2013 at 10:00:28PM +0200, Andrew wrote: > > > > The solution I can think of: calculating each joint velocity and > > acceleration before each move (at several points at least for a long > moves) > > and then decreasing XYZ velocities to fit joint velocities to their > limits. > > This is exactly the solution Seb, Jeff, and I have talked about > several times. I like the simplicity of the idea where you just > look along the move until you find where you're exceeding joint > constraints the worst, then if you are, scale back accordingly for > the whole move, and plan it in world space like usual. > > Yes, that is very reasonable. Just calculate the scale and use usual planning. The task can also be reversed: increase world velocity to the maximum allowed by joint constraints. This can be useful for G0 moves.
> It would be hard to know how much "searching" along the path you'd > need to do, but on a well-behaved machine where the singularities > aren't too close to the working volume, a bit of binary search > would give you a very good idea. Perhaps you could know to stop > searching when you get down to a few encoder counts/steps, or you > could stop early if you are running out of time (we've never done > anything like that, but why not? We know the thread period.) > The number of "probing points" and/or max distance between the points along the path can be INI parameters. My guess is 8-10 points would be enough in most cases for linear moves, the circles can be more complicated. For short moves the only end point is enough (assuming the start is already checked as the end of the previous move). Andrew ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
