I think a hydraulic device could approximate it.

General concept: For each direction: a check valve in series with a small-diameter-tube would realize a roughly constant pressure difference, as long as there is some very small flow (i.e. cylinder movement). This could then operate a pilot valve, opening the larger main valve, allowing much more flow once the pre-set amount of pressure (i.e. force on the cylinder) is reached.

(it wouldn't be this neat in a real implementation)

I think a hydraulic device could approximate it.

General concept: For each direction: a spring-loaded check valve (ie with a cracking pressure) in series with a small-diameter-tube would realize a roughly constant pressure difference, as long as there is some very small flow (i.e. cylinder movement). This could then operate a pilot valve, opening the larger main valve, allowing much more flow once the pre-set amount of pressure (i.e. force on the cylinder) is reached.

(it wouldn't be this neat in a real implementation)

Conceptually, I think a hydraulic device could approximate it.

For each direction: a check valve placed in opposition to a small-diameter-tube would realize a roughly constant pressure difference, as long as there is some very small flow (i.e. cylinder movement). This could then operate a pilot valve, opening the larger main valve, allowing flow once the pre-set amount of pressure (i.e. force on the cylinder) is reached.

(it wouldn't be this neat in a real implementation)

I think a hydraulic device could approximate it.

General concept: For each direction: a check valve in series with a small-diameter-tube would realize a roughly constant pressure difference, as long as there is some very small flow (i.e. cylinder movement). This could then operate a pilot valve, opening the larger main valve, allowing much more flow once the pre-set amount of pressure (i.e. force on the cylinder) is reached.

(it wouldn't be this neat in a real implementation)