CLOSED-LOOP CONTROL SYSTEM FOR CONTROLLING A DEVICE

摘要

A closed-loop hydraulic control system that may arrest the motion of attached devices in the event of loss of electrical or hydraulic power or in the event of an emergency. Gangways from a ship to a platform and ladders on fire trucks may have hydraulic control systems that allow for free motion in several different directions in order to keep stability in rough waters or shifting ground. If the gangway or ladder begins to fall due to loss of hydraulic power or a failure in the securing of one end, the closed-loop control system may detect these situations and actuate the closing of valves to limit or stop the falling motion of the gangway or ladder. Various control or damping algorithms may be employed to yield a desired and controlled arresting of motion so as to prevent injury and damage.