ABSTRACT
Leakage compensation in constant load speed hydraulic systems is highly required
to have a precise control of the job target. To achieve this two options are available,
either pump control or flow control. In the present work, experimental investigation
of a constant load speed system test rig equipped with proportional electro-hydraulic
valve and variable pump is studied. The leakage compensation has been achieved
by controlling the proportional electro-hydraulic valve input volt or controlling the
pump speed through frequency modulator. The study aims to highlight the difference
between these two control options on the dynamic and steady state response of the
system. The supply and return cylinder pressures, cylinder displacement and flow
rate are recorded. Different external leakages have been intentionally introduced in
the connections to the flow control valve to simulate the external system leakage.
Results showed that the dynamic and steady state system performance have been
affected by the system leakage. The volt control signal for proportional DCV and
frequency control for pump control could be used for leakage compensation through
controller with a precise control algorithm to compensate leakage in electrohydraulic
proportional systems.