Electro-hydraulic proportional control of twin-cylinder hydraulic elevators

摘要: Abstract The large size of the cab an electro-hydraulic elevator necessitates arrangement two cylinders located symmetrically on both sides cab. This paper reports design system which consists three flow-control proportional valves. Speed regulation and synchronization control are also presented. A pseudo-derivative feedback (PDF) controller is applied to obtain a velocity pattern that proves be close given one. non-synchronous error kept within ±2 mm with constrained step proportional-derivative (PD) controller. solenoid-actuated non-return valve, i.e. hydraulic lock, developed prevent sinking allow easy inverse-fluid flow.