Journal of Engineering Research and Reports

Synchronised displacement of dual hydraulic cylinders is important for the controlled operation of lifting gates, particularly when flow distribution and loading differ between actuators. This study evaluates a bypass bleed-off synchronisation arrangement for a dual-cylinder hydraulic hoist using AMESim simulation. A single proportional directional valve supplies both cylinders in parallel, while an individual proportional bleed-off valve, connected through a four-check-valve rectifier bridge, regulates the corrective flow for each cylinder. A proportional–integral–derivative controller uses the measured displacement difference to select and actuate the appropriate bleed-off valve, with separate branch gains accommodating the extension and retraction directions. The simulated model includes hydraulic components, cylinder friction, displacement measurement dynamics and the specified operating parameters. Five cases examine an uncontrolled baseline, closed-loop regulation, unequal cylinder loads, proportional-gain sensitivity and a complete extension–retraction cycle. In the reported simulations, the uncontrolled displacement difference increases to approximately 21 mm over a 2 m stroke. With the tuned controller, the steady-state synchronisation error remains within ±1.5 mm under equal loading and below 1.5 mm with a load increase of up to 30% on one cylinder. The results also show that controller tuning affects oscillatory behaviour and that correction is possible in both stroke directions. These simulation findings indicate the potential of bypass bleed-off regulation as a comparatively simple synchronisation approach for existing gate-hoist circuits. Experimental verification remains necessary before practical performance can be established.