You might be making this more difficult than need be. If you tell the drive to go to a position via a path and while executing that path you have very little following error, then how could that be improved upon?
The stiffness of your drive system will be more related to the size of your servo drive and motor than whether you control it via torque or velocity mode assuming your pid tuning is good. When you put the drive into velocity mode, the torque/current loop is handled inside the drive itself. Which is probably the best place for it. If you get into the fine details, don't overlook the parameters that your supplier loaded into the Aries drive. Are you sure he did that correctly? The last time I set up an Aries drive the software was available on the web. Dave On 4/5/2012 8:32 PM, lloyd wilson wrote: > We are investigating using my favorite cnc controller for an application > which will require as much stiffness as we can arrange; websearching > suggests that torque mode rather than velocity mode is preferrred in > such applications. We are using a Pico PPMC interface set to mediate > between the computer and a Parker Aries amp/motor combination (+/- 10v > control input, 2000 line encoder, vendor rep loaded any requisite motor > parameters into the amp). We finally have the system so it doesn't > immediately fault on a following error, but only in velocity mode; we've > been totally unable to generate a set of PID parameters that are viable > when the amp is set to torque mode. Ergo, it's guru time- > > 1 - is there some inherent incompatibility between Linux CNC and torque > mode servos? > 2- is there some deeply buried config parameter that needs to be changed? > 3- can somebody point us to a strategy specifically oriented to tuning > torque mode servos? > 4- any other ideas? > > as always, thanks in advance - this community never stops astounding me > with its knowledge and its willingness to share > > > lloyd > > ------------------------------------------------------------------------------ > For Developers, A Lot Can Happen In A Second. > Boundary is the first to Know...and Tell You. > Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! > http://p.sf.net/sfu/Boundary-d2dvs2 > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > ------------------------------------------------------------------------------ For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
