On 22 May 2012 15:01, Claude Froidevaux <men...@bluewin.ch> wrote: > Basically, the concept is to use the motor encoder for high frequency > information (Derivative term of the PID), and the glass scale for the > Integrator term. Things start to get complex for the P term.. it may be > a mix of both, or different algorithm
You can simply add the outputs of two PID controllers together in this sort of setup. Alternatively you could use the output of a position PID controller which uses the glass scales as feedback as the input to a second PID controller which uses the motor velocity (or possibly position) for feedback. The latter solution ought to work well for machines with tachometers on the servos, except I don't know of very many high-bandwidth, pipolar, analogue-input devices for LinuxCNC. (The Mesa 7i65 looks like it might work, but I don't know if it has been tried). It has just occurred to me that it might be possible to combine tacho and command voltages completely in the analogue domain for these machines… -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
