2011/9/20 Dave <e...@dc9.tzo.com> > I would think that this would be very hard to implement successfully. > You are talking about optimizing the acceleration settings to a > particular motor/drive/load setup. > > I can only see this being of a benefit if you were running a fixed part > with the same cutter over and over again with a undersized or poorly > sized drive system. If you changed materials or cutters or the > carriage mass you might have to > retune everything. >
The main idea it to use motors at full capacity. Now maxaccel is limited by torque value at max speed, but it sometimes could be 2-3 times larger at low speeds, resulting in 1.5-2 times shorter acceleration distance. That would be especially noticeable at short moves. The norm is to make sure that you are not operating your motors that > close to the edge of their torque curve. > A machine with accels tightly fitted to the motor/drive/load would be > very unforgiving. > But at least we might balance the torque reserves at high and low speed. That is, use more capacity of motors, again. > Servos can operate beyond their ratings for short periods of time which > sometimes makes them more forgiving, especially if you increase the the > max following error allowed. When I tune my servos with pncconf, I have stable alternate motion with 10 m/s2 up to 7 m/min speed, with 5 m/s2 up to 9-10 m/min etc. With higher values there's an overload and stop. It looks like lack of capacity at higher speed. Thus, if I want faster acceleration I should limit max speed, if want more speed I should completely suppress the acceleration. But with variable acceleration I could use almost all I have! 2011/9/20 andy pugh <bodge...@gmail.com> > Currently stepgen maxaccel is a parameter, not a pin, so it would need > to be changed to a pin to make it possible to change it in real-time > from HAL. > However, that is only part of the story. I think that the max accell > for the Trajectory Planner is read in once at load-time from the INI > file. That would have to be turned into a HAL pin too (again, > possible, but work) Wouldn't it be easier to change main motion equation to take into account jerk (thanks Bryce), and add some new parameter to stepgen? Andrew ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity and more. Splunk takes this data and makes sense of it. Business sense. IT sense. Common sense. http://p.sf.net/sfu/splunk-d2dcopy1 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
