Errors which (may) occur when positioning hydraulic drives. They consist of;
- the Δs N,
- errors associated with hysteresis and the reversal error for the continuously adjustable valve (between 0.1% and 2 to 3%),
- errors resulting from friction in the drive,
- errors caused by the presence of an external load. They are dependent on the size of the load, the pressure gain at the valve and the loop gain vK.
All these errors are more or less cancelled out if appropriate measures are taken at the position control stage.