On Wed, 2 May 2012 15:23:25 +0300, Viesturs Lācis wrote: > > Thank You! Not sure that I understand, how exactly introducing > "jounce" helps reducing vibrations. > Jerk is clear to me - one good way to test it is, when driving a car: > when You have to stop, press brake pedal with some force and do not > change that force. At the moment, when velocity (car's speed) reaches > 0, acceleration instantly jumps from some negative value to zero and > everybody in the car will feel it - as if they were released and > thrown back into seats. > "Jounce" is something new and not yet clear, how it helps...
If you think out it in terms of orders of differentiation it might help, or not, but I'm game to try... d0 (of motion) = pos d1 = velocity d2 = acceleration d3 = jerk d4 = jounce If you do not have any control over acceleration, so your movement jumps from one speed to the next, then you get lots of vibration in the mechanisms. If you allow some control over the transition you can cut down a lot of the vibration and can increase the accuracy of the machine. You can do this for increasingly higher order and dampen out increasingly higher order harmonics. If you look at the n'th derivative of whatever motion equation you are playing with, then as long as the equation is complex enough to take a n'th order derivative then, you can optimize it for smoothness. The end result is that it willl always tale a little longer to make higher order smooth transitions, but it will reduce more and more vibration in the machine. Does that help? If not then just ignore... EBo -- ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
