Re: [Emc-users] Invisible position sensing [Was: A new real-time Linuxscheduler released]
On Fri, Nov 2, 2012 at 6:02 AM, Erik Christiansen dva...@internode.on.netwrote: On 01.11.12 18:40, Peter Blodow wrote: How is the position of the balls rsp. the pendulum detected? Peter My guess is that the beam pivot has a servo motor and quadrature encoder. If the ball is off-center, then the beam pivots, unless sufficient restoring torque from the motor is applied. The amount of torque (current) required at any instant would then be a measure of ball position, if the beam is not accelerating, I figure. For that system in particular a linearized model is feasible and very light computationally, then, as you can obtain acceleration from the encoder, then you can have a model based position feedback. I would choose a Kalman filter approach, to cope with the noise in acceleration, and maybe simultaneous identification of the relevant inertia and friction parameters. You can as well use a nonlinear model (then extended Kalman filtering) for extra precision. Javier If the pendulum is constrained to one axis of rotation, then one encoder on the pivot is all that is needed there as well. Erik -- In the bathtub of history the truth is harder to hold than the soap, and much more difficult to find. - Terry Pratchett -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] I crashed my machine, now I need a new drill chuck
On 31 October 2012 14:02, Stuart Stevenson stus...@gmail.com wrote: I have tried hydraulic chucks end mill holders. How do they work? I had imgined that they were based on the SKF Oil-injection idea ( http://www.mapro.skf.com/products/oil_oim.htm ) but looking around the web it appears that they may simply have a cavity round the tool hole with a fairly thin wall and then a screw which pushes hydraulic fluid into the cavity. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] A new real-time Linux scheduler released
On 11/1/2012 1:26 PM, MC Cason wrote: For anybody who's interested: http://www.osnews.com/story/26505/SCHED_DEADLINE_v6_released/ At the bottom, there's a link to a youtube video, but this is the full video (4:28): http://www.youtube.com/watch?v=UJSWvC-QnjI ... The demo has been realized for the ACTORS project (http://www.actors-project.eu) financed by the European commission. Discover SCHED_DEADLINE at http://www.evidence.eu.com/sched_deadline.html Version 1 appeared in 2009 so it's been in development for some time. I admit I haven't read all the documentation available but the examples I did see use task and cycle times a thousand times slower than we use in LinuxCNC. For example, As a proof of concept, we implemented a very simple test to run two tasks that need to execute for 20msec every 50msec. Is there any latency data for this scheduler running, say, a 20-microsecond task every 50 microseconds? Regards, Kent -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] A new real-time Linux scheduler released
On 11/02/2012 09:53 AM, Kent A. Reed wrote: Version 1 appeared in 2009 so it's been in development for some time. I admit I haven't read all the documentation available but the examples I did see use task and cycle times a thousand times slower than we use in LinuxCNC. For example, As a proof of concept, we implemented a very simple test to run two tasks that need to execute for 20msec every 50msec. Is there any latency data for this scheduler running, say, a 20-microsecond task every 50 microseconds? Regards, Kent I haven't found anything else about it yet. Between writing code, designing circuit boards, and cleaning up tornado damage, I'm pretty swamped. I was hoping somebody else had more detailed information about it. -- MC Cason - Assocaite Developer - Eagle3D Created by: Matthias Weißer http://www.matwei.de/doku.php?id=en:eagle3d:eagle3d http://developer.berlios.de/projects/eagle3d/ -- LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
