synthetos
Implement proper pressure management for 3D printing
Manage the pressure of the filament in the extruder (open-loop) based on a spring and dashpot model.
I would suggest the label we want is "predictive extrusion management" (or the like), as the end-to-end goal is to extrude a precise amount of plastic (perhaps zero) at a reasonably precise temperature.
To get to the end result, we will need to vary the heat input into extruder, planned in advance to allow heat to soak through the metal into the plastic. (Rapid increases in extrusion rates will cool the head.) For slow rates of printing, the reactive temperature loop is adequate, mostly. For faster printing, we need predictive heating (and perhaps feedback into motion planning, slowing down if needed to allow heat transfer).
Marlin contains a number of hacks to approximate solving intermediate problems. The "pressure advance" stuff is one of those. I very much doubt a cheap 8-bit CPU is adequate to solving the end-to-end problem.
This is one reason I am interested in g2core. If we are going to do more advanced planning for extrusion, no way I want to attempt this in Marlin. :)
(The fact that in Bowden setups the properties of the long PTFE tube and plastic filament as a spring, adds another layer of horror.)
Written about this before: https://plus.google.com/u/0/+PrestonBannister/posts/dTjQ2FMXus2
