Is it possible to calculate the "hydraulic​-translati​on-multibo​dy"-system backwards?

The system shown in the picture works wonderfully as it is. The only problem is that I don't want to specify the valve position and get forces, movement, etc. from it. Rather, my intention would be to specify the movement on the prismatic joint (with derivatives as input at the p-port) and to get the forces and the necessary valve position from it.

My current opinion is that this cannot work (as easy as i want), but I would also like to be taught better.

Another consideration would be to install an ideal pressure source instead of the pump and to measure the volume flow, from which I can then calculate the valve position. But I have not yet tested whether it works like that.

Thanks in advance!

Answer 1

[Yifeng Tang]

I would agree with you that the valve position couldn't be calculated the way you described. The force, though, can be found by driving the prismatic joint with position input and sense the joint actuation force by turning it on in the joint block.

A workaround to get the valve position needed may be to use a feedback control. Put in a controller, PID maybe, for the spool position so the position of the primatic joint tracks the desired signal. You may be able to tune the controller to achieve that, and from there, you get ONE solution of the valve position to achieve the joint motion.