The positioning ability of an induction motor is no different to that of a DC servo motor. When no torque is needed both go to zero voltage/current to stop moving (though technically an induction motor can maintain a DC current if it chooses to to provide braking - similar to shorting out the DC motor leads.) When torque is needed to maintain position excitation must be applied to each. Only difference is one is DC and one is AC. There are plenty of AC induction servos. They are typically one of the highest performance machines as the rotor inertia can be made lower than DC or PMSM rotors. It does take more advanced control software. Also, the wider torque vs speed curves are typically unmatched.
On Sun, Jan 24, 2016 at 9:37 AM, Dave Cole <linuxcncro...@gmail.com> wrote: > Is the positioning ability adequate? > > Most squirrel cage motors are really bad at positioning under load as > they rely on slip to generate armature flux. No slip -> no flux -> no > torque But you are just trying to position the tool for the changer, > right? > > The best I have seen for positioning with a load is basically a > coast/brake to a stop position and then a brake is applied at the stop > position. > > Is there a reason why you did not use the hal component that Andy > pointed out? Or did you modify that? > > Dave > > On 1/24/2016 7:19 AM, Marius Alksnys wrote: > > and in orientation / position mode I_out is constant and f_out is > > controlled by PID. > > > > > > > ------------------------------------------------------------------------------ > > Site24x7 APM Insight: Get Deep Visibility into Application Performance > > APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month > > Monitor end-to-end web transactions and take corrective actions now > > Troubleshoot faster and improve end-user experience. Signup Now! > > http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > ------------------------------------------------------------------------------ > Site24x7 APM Insight: Get Deep Visibility into Application Performance > APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month > Monitor end-to-end web transactions and take corrective actions now > Troubleshoot faster and improve end-user experience. Signup Now! > http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
