Stuart Stevenson wrote: >Gentlemen, > I have been thinking. :) > > 1: Since the forward and inverse calculations must match is there >any reason to calculate both for all modes of operation? Depending on >the mode shouldn't you be able to skip the unneeded calculation? This >would allow twice the calculation time and not lose any speed. A mode >change could change the calculation path through the kins. > > A mode change of what type?
> or > > 2: A matrix stack would allow both calculations at the same time. >The kins would calculate a matrix for the forward kins and do an >inverse calculation of the resulting matrix for the inverse kins (or >vice versa). The kins would not have to recalculate the whole stack >for both forward kins and inverse kins. > > Each time the servo thread runs, EMC needs to do both sets of calculations once, but it does the calculations on different poses. First, feedback is fed through the kinematics function to tell EMC where the machine is. EMC can then do following error checks, and can create a new pose to send out as the next position command. Since that pose is in cartesian coordinates, but it needs to be sent to the actual machine joints, that has to be run through inverse kinematics to make a valid machine pose. A matrix solution would be good, but since the transforms are done on different poses each cycle, they can't be done at the same time. Note 1: I may have screwed up which is "kinematics" and which is "inverse kinematics". if so, please swap where appropriate :) Note 2: I didn't look at the code before writing this, nor did I have any coffee. YMMV. - Steve ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
