LinuxCNC S-Curve Accelerations

Hello,

Just for fun i also created a Polygon program where you can change direction (G2/G3), position, number of point/rounds and the corner radius.

For what option is chosen, doesn't the user choose with P-parameter of G64, how much the controller can deviate from the programmed points? Also by option 1, and acute angles should there be a user option to tell what is acute.

(long time reader, trying to do something back to the community, keep up the good work!)

Actually, when I think about the proposed integration of 9axis blending, it might indeed be wiser to stick to the circular arc.


In any case, at the end of the day it will always be better to have something that works than something that might be even better but never gets done. So thank you guys for working on this.

I'm not expert too, I've just been experimenting with AI and looking at the halscope, trying to wrap my head around things in general, it helps to just chat about these things, even just to make sure I'm not persuing a weird irrational tangent, and I'm actually making sense not just to myself lol. YangYang has the math down, he is the main arbitror, nothing goes to master without his stamp of approval, and he checks on what the AI comes up with, and so far nothing really sticks, only what he write himself works best. I've found something with the arcs, I want him to take a look, and I think we maybe possibly be able to do similar tricks with Béziers, but I don't want to keep your hopes up, I think it is possible that, the fact that Béziers change curvature, may not fit with the current tp lokahead/blending architecture, but maybe... maybe I am wrong.

I thought jerk limiting was purely about acceleration. To extend it to varying the path seems to me is really scope creep. Get it working without changing the path and include path optimisations at a future time and write better gcode for now.

jerk limiting may permit higher maximum acceleration. Currently MAX_ACELERATION is set from a combination of motor dynamics and physics by the machine builder Eg the inertia in a heavy moving table may require a lower acceleration than what the motors are capable of so they are not overcome by inertia on deceleration and cause following errors. Its probably valid on a jerk limited machine to increase acceleration. In this context, some violations may be valid.

Jerk limit to the point of seeing your machine move sluggishly? Béziers are Just to be able to get better cornering speeds, because tangent arcs are not optimal for covering with jerk limit.
Scope of planner type 1 is jerk limit to a crawl if necessary? Like the 0.0001 G2 curves that ruediger123 shared. Done with small G64P tolerance, I agree those should just slow down as much as you need to follow path within tolerance, BUT for a square with NO programmed corners, blend with arcs and parabolas are acceptable? Just slow down as much as we need to follow the blend arc? Point cloud line to line is another issue, slow down to keep everything smooth? but then you will see the machine smoothly follow your point cloud, but it will speed up and slow down, speed up and slow down, because we are not trying to maintain velocity, we are sacrificing it, and because we work mostly segment by segment, I don't see an easy way out, Béziers could give us a better path, but we will need to figure out where and how to stitch them smoothly. and how to do it while the machine is in execution, we can't plan the whole thing offline.

What I mean it it becomes development hell and the project dies, and it is the least critical part of the system we need.

Sure, it is absolutely what we want in the end, but getting there is just not happening.

Option 1 is likely a completable project and "good enough for now".