Characteristic curves

When hydraulic cylinders are used together with the appropriate valves, the way in which the cylinder and valves are constructed often results in a non-linear transmission behavior of the axis, and thus of the system that is to be controlled.

The velocity of the hydraulic cylinder is not, in other words, proportional to the valve's drive signal. This can occur, for instance, if a hydraulic cylinder is used in which the two faces to which pressure is applied to not have a 1:1 area ratio.

Non-linear valve characteristic curves are another typical reason for this behavior. The following diagram illustrates a possible form for such a characteristic curve.