Error sensing system for vessels with absolute zero referencing
First Claim
1. In a system for automatic steering of a vessel wherein a compass disk is aligned with the heading North, and sensing means are associated with said compass disk to sense the relative movement between said disk and said sensing means in response to changes in the heading of said vessel with respect to North, the improvement comprising:
- said disk having a first direction error surface portion provided with opaque and transparent areas defining a zero reference position therebetween and a second magnitude error surface portion disk provided with a second zero reference position thereon aligned in predetermined relation to said first zero reference position and an area extending along said second surface portion which varies in transparency away from said second zero reference position;
said sensing means having first and second light sensors aligned with said first and second surface portions, respectively, said first light sensor generating a direction error signal in response to relative movement between said sensing means and said first surface portion, and said second light sensor operative to generate a magnitude error signal in response to relative movement between said second surface portion and said sensing means; and
control circuit means operative in response to simultaneous generation of direction error and magnitude error signals by said sensing means to produce a correctional signal to modify the heading of said vessel until said zero reference positions return into alignment with said light sensing means.
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Accused Products
Abstract
An error sensing system for use in marine autopilot systems of the type having a photographic film compass disk aligned with the direction North and sensing means associated with the disk is operative to sense relative movement between the disk and the sensors in response to changes in the heading of the vessel. A first direction error surface portion on the disk has opaque and transparent areas defining a zero reference therebetween, a second magnitude error surface portion on the disk has a second zero reference position in predetermined relation to the first zero reference position and an area of variable transparency extending along the second surface portion. The first and second surface portions are defined by images along the peripheral surface of the photographic film disk. The disk sensing system has first and second light sensors aligned with the first and second surface portions, respectively, to generate direction error and magnitude error signals representative of the direction and extent of movement of the vessel away from a given heading.
23 Citations
15 Claims
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1. In a system for automatic steering of a vessel wherein a compass disk is aligned with the heading North, and sensing means are associated with said compass disk to sense the relative movement between said disk and said sensing means in response to changes in the heading of said vessel with respect to North, the improvement comprising:
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said disk having a first direction error surface portion provided with opaque and transparent areas defining a zero reference position therebetween and a second magnitude error surface portion disk provided with a second zero reference position thereon aligned in predetermined relation to said first zero reference position and an area extending along said second surface portion which varies in transparency away from said second zero reference position; said sensing means having first and second light sensors aligned with said first and second surface portions, respectively, said first light sensor generating a direction error signal in response to relative movement between said sensing means and said first surface portion, and said second light sensor operative to generate a magnitude error signal in response to relative movement between said second surface portion and said sensing means; and control circuit means operative in response to simultaneous generation of direction error and magnitude error signals by said sensing means to produce a correctional signal to modify the heading of said vessel until said zero reference positions return into alignment with said light sensing means. - View Dependent Claims (2, 3, 4, 5)
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6. In an autopilot system for automatic steering of marine craft wherein an aperture plate is associated with a compass disk to sense the relative movement between said disk and said plate in response to changes in the heading of said craft with respect to North, the improvement comprising:
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a first direction error track on said compass disk having opaque and transparent areas defining a zero reference area therebetween; a second magnitude error track on said compass disk having a second zero reference position thereon aligned in predetermined relation to said first zero reference position, and light control means extending along said second track away from said second zero reference position; said aperture plate having first and second light sensing means aligned with said first and second tracks, respectively, said first light sensing means generating a direction error signal in response to relative movement between said aperture plate and said disk, and said second light sensing means operative to generate a magnitude error signal in response to relative movement between said aperture plate and said disk; and control circuit means operative in response to simultaneous generation of direction error and magnitude error signals by said light sensing means to produce a correctional signal to modify the heading of said vessel until said light sensing means return into alignment with said reference positions. - View Dependent Claims (7, 8, 9)
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10. In an error sensing system for sensing angular displacement of a movable object away from a reference point wherein said system has a magnetic compass disk aligned in predetermined relation to said reference point and said object is angularly displaceable independently of said compass disk, the improvement comprising:
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light emitter means disposed on one side of said compass disk, first and second light sensing means disposed on an opposite side of said compass disk in the path of light directed through said compass disk from said light emitter means, direction error means on said compass disk in the path of light from said light emitter means to said light sensing means, said direction error means having a first zero reference position aligned with said reference point and being operative to produce one predetermined level of light in one direction of angular displacement away from said first zero reference position and another predetermined level of light in an opposite direction of angular displacement away from said zero reference position; magnitude error means disposed in the path of light from said light emitter means to said second light sensing means and having a second zero reference position aligned with said reference point, said magnitude error means operative to produce predetermined variations in light intensity symmetrically in opposite directions of angular displacement away from said second zero reference position; and control circuit means operative in response to receiving direction error signals indicative of the direction of movement away from said first zero reference position and magnitude error signals indicative of the magnitude of angular displacement away from said second zero reference position to produce bipolar error signals representing the direction and magnitude of angular displacement away from said first and second zero reference positions. - View Dependent Claims (11, 12, 13, 14, 15)
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Specification