MATLAB: Does the Hard-stop of the Hydraulic Cylinder does not seem to be respected in SimHydraulics 1.5 (R2009a)

Simscape Fluids

I have a SimHydraulics model which has a dual acting cylinder in it.
When I run the simulation, the ideal translational motion sensor shows the displacement of the cylinder to be more then the stroke that I specified in the component.

Best Answer

The hard-stop of the SimHydraulics cylinder is implemented as a spring and damper system. When a large pressure is applied to the cylinder, the hard-stop might not be stiff enough to have a significant effect and limit the piston motion.
In the attached model, the pressure applied is of the magnitude of 4000psi. In the cylinder configuration, the hard-stop stiffness is only 1e6 N.
Therefore, the cylinder is just pushing through the hard stop and the effect of the hard-stop is not significant.
To workaround the issue, increase the hard stop stiffness to 1e9, you will see the cylinder stroke limited as expected.
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