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US 6,584,384 B2Granted
Device, method and computer program product for altimetry system
AssigneeHoneywell International Inc.
InventorsScott Gremmert, Steven C. Johnson, Glen Burlingame
Life of this patent
Estimating the term…
Abstract
An apparatus, system, method and computer program product to verify proper operation of an aircraft altimetry system. Aural and visual alerts may optionally be provided when a fault in the altimetry is detected.
Claims76
An apparatus for detecting faults in aircraft altimetry comprising:
- (a) a first logic having:
- (i) an input coupled to receive a Gray-coded altitude;
- and
- (ii) error logic to detect an error in said Gray-coded altitude;
- (iii) an output for asserting a first error signal when said error is detected;
- (b) a second logic having;
- (i) an input coupled to receive a pressure altitude data and a secondary source of altitude data;
- (ii) altitude rate logic to compare a first rate of change of said pressure altitude data and a second rate of change of said secondary source of altitude data;
- and
- (iii) an output for asserting a second error signal when said first and second rate of change differ by more than a predetermined amount;
- (c) a third logic having:
- (i) an input coupled to receive said pressure altitude data and a tertiary source of altitude data;
- (ii) a comparison logic to obtain a difference between said pressure altitude and said tertiary source of altitude data;
- (iii) a error budget logic that obtains an error budget based on known characteristics of said pressure altitude data and said tertiary source of altitude data;
- (iv) an output for asserting a third error signal when said difference exceeds said error budget;
- and
- (d) an alerting logic having:
- (i) an input coupled to receive said first error signal, said second error signal and said third error signal;
- and
- (ii) an output for asserting an alert signal when at least one of said first error signal, said second error signal and said third error signal is asserted.
17 more elements
An apparatus for detecting errors in Gray-coded altitude comprising:
- a first logic for comparing a current Gray-coded altitude to a previously sampled Gray-coded altitude and for asserting a first signal when said current code and said previously sampled code are not identical and for obtaining a difference between said current code and said previously sampled code;
- a second logic for comparing said difference to a first predefined error condition and asserting a first error signal when said difference matches said predefined error condition and when said first signal is asserted;
- a third logic for comparing bits C1, C2, C4 of said current code to a predetermined set of invalid bit sequences and for asserting a second error signal when said current code matches at least one of said invalid bit sequences;
- and
- an output for asserting a Gray-coded altitude error signal when at least one of said first error signal or said second error signal is asserted.
2 more elements
An apparatus for detecting errors in aircraft altimetry comprising:
- an input for receiving a first and second source of altitude data;
- a first logic to obtain a difference in a rate of change of each of said first and second sources of altitude data;
- and
- a second logic for comparing said difference to a predetermined value and for asserting an altimetry error signal when said difference exceeds said predetermined value.
1 more element
An apparatus for detecting errors in aircraft pressure altitude measurements comprising:
- an input for receiving a pressure altitude data and a geometric altitude data;
- a first logic for obtaining a difference between said pressure altitude data and said geometric altitude data;
- a second logic for defining a first probable error between said geometric altitude data and said pressure altitude data based on a standard atmosphere;
- a third logic for defining a second probable error due to deviations from nonstandard atmospheric conditions;
- and
- a fourth logic for comparing a sum of said first and second probable errors to said difference and asserting a pressure altitude error signal when said difference exceeds said sum.
3 more elements
A method for detecting errors in Gray-coded altitude comprising the steps of:
- comparing a current Gray-coded altitude to a previously sampled Gray-coded altitude and asserting a first signal when said current code and said previously sampled code are not identical;
- obtaining a difference between said current code and said previously sampled code;
- comparing said difference to a first predefined error condition and asserting a first error signal when said difference matches said predefined error condition and when said first signal is asserted;
- comparing specified bit positions of said current code to a predetermined set of invalid bit sequences for said bit positions;
- asserting a second error signal when said current code matches at least one of said invalid bit sequences;
- and
- asserting an altitude error signal when at least one of said first error signal or said second error signal is asserted.
4 more elements
A method for detecting errors in altimetry comprising the steps of:
- obtaining a difference in a rate of change of each of a first and a second sources of altitude data;
- and
- comparing said difference to a predetermined value;
- and
- asserting an altimetry error signal when said difference exceeds said predetermined value.
2 more elements
A method for detecting errors in altimetry comprising the steps of:
- obtaining a difference between a pressure altitude data and a geometric altitude data;
- defining a first probable error between said geometric altitude data and said pressure altitude data based on a standard atmosphere;
- defining a second probable error due to deviations from nonstandard atmospheric conditions;
- and
- comparing a sum of said first and said second probable errors to said difference and asserting a pressure altitude error signal when said difference exceeds said sum.
2 more elements
A computer program for detecting Gray-coded altitude errors comprising:
- a computer readable storage medium having computer readable program code means embodied in said medium, said computer readable program code means having:
- first computer instruction means for comparing a current Gray-coded altitude to a previously sampled Gray-coded altitude and asserting a signal when said current code and said previously sampled code are not identical;
- second computer instruction means for comparing said current code to said previously sampled code to obtain a difference;
- third computer instruction means for comparing said difference to a predefined error condition and asserting a first error signal when said difference matches said error condition and said first signal is asserted;
- fourth computer instruction means for comparing specified bit positions of said current code to a predetermined set of invalid bit sequences for said bit positions;
- fifth computer instruction means for asserting a second error signal when said specified bit positions match at least one of said predetermined set of invalid bit sequences;
- and
- sixth computer instruction means for asserting an altitude error signal when at least one of said first error signal or said second error signal is asserted.
5 more elements
A computer program product for detecting errors in altimetry comprising:
- a computer readable storage medium having computer readable program code means embodied in said medium, said computer readable program code means having:
- first computer instruction means for accessing a first source of altitude data and a second source of altitude data;
- second computer instruction means for obtaining a difference in a rate of change of said first source of altitude data and a rate of change in said second source of altitude data;
- third computer instruction means for comparing said difference to a predetermined value;
- and
- fourth computer instruction means for asserting an altimetry error signal when said difference exceeds said predetermined value.
3 more elements
A computer program product for detecting errors in altimetry comprising:
- a computer readable storage medium having computer readable program code means embodied in said medium said computer readable program code means having:
- first computer instruction means for accessing a pressure altitude data and a geometric altitude data;
- second computer instruction means for obtaining a difference between said pressure altitude data and said geometric altitude data;
- third computer instruction means for defining a first probable error between said geometric altitude data and said pressure altitude data;
- fourth computer instruction means for defining a second probable error due to deviations from a standard atmosphere;
- and
- fifth computer instruction means for comparing a sum of said first and second probable errors to said difference and asserting a pressure altitude error signal when said difference exceeds said sum.
4 more elements
Dependencies are inferred from the claim text.