Rudder error detector
AssigneeSperry Rand Corporation
InventorCharles R. Wesner
Life of this patent
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Abstract
Apparatus for detecting malfunctions in rudder-type steering systems utilizes electrical order and rudder angle signals. The rudder-order signal is applied to a closed-loop simulator that includes integrating apparatus adjusted to provide a time-variant simulated rudder angle signal which varies in the same manner that the actual rudder angle signal would vary in the absence of a malfunction when exposed to the same rudder error signal. The simulated and actual rudder angle signals are compared in a summing amplifier whose output is applied to a thresholding circuit which actuates an alarm whenever the instantaneous values of the simulated and actual rudder angle signals differ by more than a predetermined amount.
Claims4
Apparatus for detecting a malfunction in a ship's hydraulic steering system employing a plurality of pumps, said apparatus including means to provide rudder order and actual rudder angle signals indicative of the instantaneous position of the helm and rudder, respectively, simulator means for providing a simulated rudder angle signal indicative of the expected response of the rudder to an order signal, said simulator means including an adjustable integrating means for providing a time delay approximating that experienced in the mechanical components of the ship's steering system and a separate potentiometer corresponding to each of the pumps for matching the integrator to each pump individually, means for comparing the simulated and and actual rudder angle signals, and means for actuating an alarm whenever the difference between the instantaneous values of the simulated and actual rudder signals exceeds a given threshold.
Dependencies are inferred from the claim text.