Navigation technique for detecting movement of navigation sensors relative to an object
First Claim
1. A method of operating a detecting device comprising the steps of:
- generating electrical signals, representative of a position, by a navigation sensor, said electrical signals providing sequential frames of navigational information at time intervals;
storing a first frame of navigational information generated at time N in a first memory buffer;
storing successive frames of navigational information, subsequent to said first frame, in a second memory buffer;
comparing a current frame of navigational information generated at time M to a previous frame, immediately preceding said current frame, stored in said second memory buffer and generating a first displacement value representative of a difference between said current frame and said frame of navigational information immediately preceding said current frame;
processing data based on said first displacement value to take into account movement of said navigation sensor relative to a reference when processing said data;
comparing a current frame of navigational information generated at time T, subsequent to time M, to said first frame of navigational information stored in said first memory buffer and generating a second displacement value representative of a difference between said current frame generated at time T and said first frame;
processing data based on said second displacement value so that said data is not affected by accumulated errors from other displacement values; and
storing a current frame of navigational information generated at time V, subsequent to time T, in said first memory buffer for comparison to a later frame of navigational information.
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Accused Products
Abstract
A scanning device and method for forming a scanned electronic image include using navigation information that is acquired along with image data, and then rectifying the image data based upon the navigation and image information. The navigation information is obtained in frames. The differences between consecutive frames are detected and accumulated, and this accumulated displacement value is representative of a position of the scanning device relative to a reference. The image data is then positioned-tagged using the position data obtained from the accumulated displacement value. To avoid the accumulation of errors, the accumulated displacement value obtained from consecutive frames is updated by comparing a current frame with a much earlier frame stored in memory and using the resulting difference as the displacement from the earlier frame. These larger displacement steps are then accumulated to determine the relative position of the scanning device.
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Citations
25 Claims
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1. A method of operating a detecting device comprising the steps of:
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generating electrical signals, representative of a position, by a navigation sensor, said electrical signals providing sequential frames of navigational information at time intervals; storing a first frame of navigational information generated at time N in a first memory buffer; storing successive frames of navigational information, subsequent to said first frame, in a second memory buffer; comparing a current frame of navigational information generated at time M to a previous frame, immediately preceding said current frame, stored in said second memory buffer and generating a first displacement value representative of a difference between said current frame and said frame of navigational information immediately preceding said current frame; processing data based on said first displacement value to take into account movement of said navigation sensor relative to a reference when processing said data; comparing a current frame of navigational information generated at time T, subsequent to time M, to said first frame of navigational information stored in said first memory buffer and generating a second displacement value representative of a difference between said current frame generated at time T and said first frame; processing data based on said second displacement value so that said data is not affected by accumulated errors from other displacement values; and storing a current frame of navigational information generated at time V, subsequent to time T, in said first memory buffer for comparison to a later frame of navigational information. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A detecting device comprising:
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a navigation sensor for generating electrical signals representative of a position, said electrical signals providing sequential frames of navigational information at time intervals; a first memory buffer for storing a first frame of navigational information generated at time N; a second memory buffer for storing successive frames of navigational information, subsequent to said first frame; a displacement detecting circuit for comparing a current frame of navigational information generated at time M to a previous frame, immediately preceding said current frame, stored in said second memory buffer and for generating a first displacement value representative of a difference between said current frame and said frame of navigational information immediately preceding said current frame; a processor for processing data based on said first displacement value to take into account movement of said navigation sensor relative to a reference when processing said data; a displacement detecting circuit for comparing a current frame of navigational information generated at time T, subsequent to time M, to said first frame of navigational information stored in said first memory buffer and generating a second displacement value representative of a difference between said current frame generated at time T and said first frame; and a processor for processing data based on said second displacement value so that said data is not affected by accumulated errors from other displacement values. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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Specification