SHIP'S TURN RATE CONTROL SYSTEM

• US 3,715,571 A
• Filed: 06/07/1971
• Issued: 02/06/1973
• Est. Priority Date: 06/07/1971
• Status: Expired due to Term

• Current Assignee: Sp-Marine Incorporated (Northrop Grumman Corporation)
• Original Assignee: Frederick D. Braddon
• Inventors: Braddon, Frederick D.
• Primary Examiner(s): Botz, Eugene G.
• Assistant Examiner(s): Smith, Jerry
• Application Number:
  US05/150,495
• Time in Patent Office: 610 Days
• Field of Search: 114/144R 244/77E,77S 235/150.2 340/30 318/580,585-586,588,619,624,489 330/86
• US Class Current: 701/21
• CPC Class Codes: B63H 25/24 by electrical means
• CPC Class Codes: G05D 1/0206 specially adapted to water vehicles
• CPC Class Codes: G06G 7/70 for vehicles, e.g. to determine permissible loading of ships , centre of gravity, necessary fuel

Abstract

A conventional ship'"'"''"'"'s steering system is modified to limit the degree of heeling during turns by limiting the centrifugal force developed during such turns. The present invention utilizes the fact that centrifugal force is proportional to the product of a ship'"'"''"'"'s speed and turning rate. The ship'"'"''"'"'s speed and rate-of-turn are measured and multiplied in a computer. Rudder command signals are applied to the steering mechanism through a summing amplifier. The output of the computer is used to modify the characteristics of the amplifier to a value that maintains the computer output within the acceptable limits. Thus heel control is achieved by automatically regulating the rudder positioning control.

Claims

1. A ship'"'"''"'"'s turn rate limiting system for use with marine craft of a type in which the steering apparatus produces an electrical command signal that controls rudder angle through an electrical network, said limiting system including means to produce a first electrical signal indicative of the ship'"'"''"'"'s speed, means to produce a second electrical signal indicative of the ship'"'"''"'"'s turning rate, means to produce an electrical limiting signal proportional to the mathematical product of said first and second electrical signals and means to restrict the magnitude of said command signal as an inverse function of said limiting signal.

2. The system of claim 1 wherein the means to restrict the magnitude of the command signal includes a variable gain amplifier connected to provide the command signal, said amplifier being further connected and arranged so that its gain is decreased by an increase in said limiting signal.