coaxial axes / offset comp how to

I still don't know what you are trying to do.

Is the situation that you have two 180 degree actuators and want 360 degrees of motion, or is it something more complex than that?

You could consider simply setting the encoder scale so that the PID components think that each axis has moved twice as far as it actually has. Then have two PID, both connected to the A-axis position command.

the offset comp is +/- as i need... i think possible to do that in hal usig sum+gain(-1) .... but simply i have not clear the relationship of the signal (encoder-pos, encder.veocity, joint-cmp-pos, oint.os-fb,pid ec etc...) ....

The mechanical .... 2 shaft, every one is an axes. one rotate the end effector 360° around x plave, the second one rotate the end effector of 180° around Z plane. The hollow shaft A axes is external shaft, the normal shaft and inside to A axes is B axes. when rotate A and B is stopped, the end effector rotare around X and Z plane too. To avoid this I must rotate both at the same speed and position. So B axes is stopped in relation to A axes.
A very bad draw (real sorry) of mechanical schemas ...note the pulley reduction and motor is the same for axes A and B.

k-1 wrote: A very bad draw (real sorry) of mechanical schemas

Even that picture is worth 1000 words.

So, the A-position is an offset to the B-position.

A-motor-position-cmd -> pid.A.command and B.offset.offset
A-encoder -> pid.A.feedback and axis.A.feedback

B-motor-position -> B.offset -> B.pid
B-encoder -> B.pid and B.offset.feedback
B.offset.feedback -> axis.B.feedback

A-motor-position-cmd -> pid.A.command and B.offset.offset
A-encoder -> pid.A.feedback and axis.A.feedback

B-motor-position -> B.offset -> B.pid
B-encoder -> B.pid and B.offset.feedback
B.offset.feedback -> axis.B.feedback

thanks a lot .... this " code " I clarified many things ... thanks again

Regards
Giorgio

for anyone who had difficulty understanding offset.9 component and use with feedback signals and command, similar to what happened to me ...