On the water jet site (I want to think it was CMC, but memory is hazy) the comparison between their full path pre scanning and short distance lookahead was that the full pre scan could adjust to things like a long straight followed by a series of curves and short straights by slowing down to a best possible average speed through the twisty section, still managing to speed up a bit where possible.
Short distance lookahead is always getting surprised by the next curve, causing rapid attempts to change speed and resulting in lower cut quality and more wear and tear on the machine. Compare it to a skilled race car driver who has made a practice lap and committed every twist and turn to memory, planning out all the gear changes and how fast to go at all points along the course. Short range lookahead is like a semi-skilled driver who has never been on the track before and starts the race without even a practice lap. He can see a turn or two ahead and has the skill to not run off the track, but will try to go as fast as possible all the time and is always having to stomp on the brake at every turn. The skilled driver maintains a smooth speed profile through a chicane while the amateur comes screaming in, hits the brakes hard and has to putt through the curves slowly to avoid spinning off the track. The driver who runs the course before the race ends up lapping the track faster, with less wear on the consumables. So why not have a "practice lap" simulation that can generate a complete accel/speed/decel profile for a toolpath then feed that data to LinuxCNC? ------------------------------------------------------------------------------ Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis & visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
