On Wed, 5 Jan 2022, Chris Albertson wrote:
Date: Wed, 5 Jan 2022 19:38:46 -0800 From: Chris Albertson <albertson.ch...@gmail.com> Reply-To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> Subject: Re: [Emc-users] Very good software backlash control demo.this robot that loads pencil leads it really just a software testing device. A research tool. What is new here s not the idea too use two sensors but 1) use a predictive model that says how the system will flex in the future in s given acceleration is apllied. 2) collect data while the machine is running in so that the above model is up to the millisecond calibration data. Notice the robot starts by slowly placing the lead in that speeds up at the end. The author said this is because the machine runs only as fast as it as confidence on the predictive model. Once you start an operation you coect data and can speed up in real time. To do this on a mill you would need glass encoders physically connected to the table, a rotary encoder on the servo motor. But really, you need sensors any place that can inform your physic model. Again what is new here that LCNC doe not do is attempt to predict in advance the effect of changing the motor torque. A PID loop, ow two nested PID loops can ONLY see error after the fact. PID is reactive. But real world machine always have a delay between applied torque and action because the physical material (even cast iron) is elastic.
Snip------------------------------------------------------------- This is not something that LinuxCNC does or does not do, that reflects a misunderstanding of LinuxCNC's architecture. LinuxCNCs PID is an optional hal component, as is LinuxCNC's Kalman filter...
-- Chris Albertson Redondo Beach, California
Peter Wallace Mesa Electronics _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
