> On 04/07/2016 09:57 AM, Nicklas Karlsson wrote: > > I have tried torque mode with only one loop and it is > > possible to get it to work without feed forward, descent > > or not is however another question. With FF should be > > better. Second derivtive feed foward should be sensitive > > to load variations. > Feed Forward will NEVER be sensitive to load variations. It > is derived entirely from commanded position, commanded > velocity, commanded acceleration, without any input from the > actual position, velocity, acceleration. > > Jon
Not the feed value but feed forward value will not compensate for load variations unless load is measured. Load variations will be compensated by integrator and I suspect it will be possible with a higher value for "I" in an inner loop to velocity but are not totally sure. Load variations may come from different workpiece/tool weight, tool hit/leave work piece. If load/torque come mainly from acceleration of machine weight feed forward will work great. If load/torque vary with tool/workpiece weight or machining forces feed forward will be of lower value although it may allow for higher "I". ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
