Browse Prior Art Database

Rudder Control for Ships

IP.com Disclosure Number: IPCOM000085594D
Original Publication Date: 1976-May-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 3 page(s) / 54K

Publishing Venue

IBM

Related People

Boinodiris, S: AUTHOR

Abstract

This system is to control the angular position of a ship's rudder and may be controlled by a digital navigation computer. The ship's rudder 4 is driven by a steering servomechanism 1 under control of an amplifier 2, which will move the rudder 4 to port or starboard depending on whether an input signal on line 3 is above or below a reference level.

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Rudder Control for Ships

This system is to control the angular position of a ship's rudder and may be controlled by a digital navigation computer. The ship's rudder 4 is driven by a steering servomechanism 1 under control of an amplifier 2, which will move the rudder 4 to port or starboard depending on whether an input signal on line 3 is above or below a reference level.

The rudder 4 is connected to a resolver coil 5 which is energized by an AC reference voltage source 6 providing a voltage V(ref). The voltage on coil 5 is magnetically linked to coils 7 and 8 at right angles to each other to generate Sin Theta and Cos Theta signals, respectively, on lines 9 and 10, respectively, where Theta is the angle between coils 5 and 8.

The computer's control over the desired rudder angle is by the computer 14 transmitting the digital form of the angle to a digital-analog multiplier 15 which also receives a part of V(ref), (C V(ref)), from source 6 as determined by the ratio of resistors 16 and 17, and provides an analog signal C.Tx.V(ref) where Tx is the transfer function of the digital-to-analog multiplier 15.

The output signal on line 18 is chosen to be from plus 4 to minus 4 times V(ref) for resolver 5 angles of +180 degrees to -180 degrees. The outputs on lines 9, 10, and 18 with V(ref) are supplied to a function generator 2O which provides the four functions; F(1) = K(0)V(ref) (-1-Sin theta +Cos theta +C.Tx)

F(2) = K(0)V(ref) (-3+Sin theta +Cos theta +C.Tx)

F(3) = K(0)V(ref) (3+Sin theta-Cos theta +C.Tx)

F(4) = K(0)V(ref) (1-Sin theta-Cos theta +C.Tx) on lines 21, 22, 23, and 24, respectively. These functions without the C.Tx term approximate linear functions within respective quadrants and will be zero when the resolver angle is equal to that called for by the computer 14. K(0) is a normalized precalibrated system gain.

The selection of the function to be used for rudder control is done by a quadrant dete...