Pitch alerting angle for enhanced ground proximity warning system (EGPWS)

• US 6,940,427 B2
• Filed: 04/01/2002
• Issued: 09/06/2005
• Est. Priority Date: 07/17/2001
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Bateman, Peter J.
• Primary Examiner(s): Hofsass, Jeffery
• Assistant Examiner(s): Previl, Daniel
• Application Number:
  US10/114,883
• Publication Number:
  US 20030016145A1
• Time in Patent Office: 1,254 Days
• Field of Search: 340/967, 340/966, 340/969, 340/970, 340/972, 340/973, 340/980, 340/974, 340/975, 340/976, 340/977, 340/978, 340/979, 340/959, 340/948
• US Class Current: 340/967
• CPC Class Codes: B64D 43/02 for indicating aircraft speed or stalling conditions
• CPC Class Codes: B64D 45/04 Landing aids; Safety measures to prevent collision with earth's surface
• CPC Class Codes: G01C 5/005 altimeters for aircraft G01C5/02, G01C5/06 take precedence
• CPC Class Codes: G05D 1/0808 specially adapted for aircraft

Abstract

A ground proximity warning system including a pitch angle alerting device, the pitch angle alerting device including warning logic having an input that is structured to receive a signal that is representative of the indicated pitch angle of the aircraft, the warning logic being structured to determine a difference between a pitch angle signal received on the input and a predetermined threshold, the warning logic being structured also to output a signal representative of the difference between the two signals; and an advisory indication generator coupled to accept the output of the warning logic, the advisory indication generator being structured to generate an advisory indication signal as a function of the difference between the two signals.

Claims

1. A pitch angle alerting device, comprising:

warning logic having an input that is structured to receive a signal representative of pitch angle, the warning logic being structured to;

compensate the pitch angle signal received on the input, determine that the compensated pitch angle signal is greater than a maximum threshold, and responsively output a signal representative of an excessive pitch excursion; and

an advisory indication generator coupled to accept the output of the warning logic, the advisory indication generator being structured to generate an advisory indication signal as a function of the excessive pitch excursion.

2. The device of claim 1 wherein the warning logic is further structured to compute a rate of change of the pitch angle, and to compensate the received pitch angle signal as a function of the pitch angle rate of change prior to determining that the pitch angle signal is greater than the maximum threshold.

3. The device of claim 2 wherein the warning logic is further structured to increasingly compensate the received pitch angle signal as a function of an increase in the rate of change of the pitch angle.

4. The device of claim 2 wherein the advisory indication generator generates aural alert.

5. The device of claim 1 wherein the received pitch angle signal is either compensated as a function of a rate of change in the pitch angle or free of such compensation.

6. The device of claim 1 wherein the pitch angle alerting device is operational as a ground proximity warning system for a host aircraft, the warning logic being operational by a processor and being further structured to receive a plurality of signals representing aircraft flight parameters which includes the signal representative of an excessive pitch excursion and being further structured to receive a position signal representing a position of the aircraft, the warning logic being further structured to compare the flight parameter signals and to generate a warning signal in response to predetermined relationships between selected flight parameter signals;

and

further comprising condition logic operationally connected to the warning logic, the condition logic being further structured to receive the position signal and being further structured to vary one or more of the predetermined relationships as a function of the aircraft position relative to a predetermined warning location.

7. A pitch angle alert generating circuit, comprising:

a compensation function coupled to receive an indicated pitch angle signal and structured to generate and output a compensated pitch angle signal;

a comparator coupled to receive the indicated pitch angle signal and a maximum threshold pitch angle signal and functioning to output a signal as a function of a decreasing difference between the compensated pitch angle and the maximum threshold pitch angle; and

an advisory indication generator coupled to receive the decreasing difference signal output by the comparator and to generate an excessive pitch excursion advisory indication as a function of the decreasing difference signal.

8. The circuit of claim 7, further comprising a selection function coupled between the compensation function and the comparator for coupling the compensated pitch angle signal to an input of the comparator.

9. The circuit of claim 8 wherein the compensation function is further structured to receive a signal representative of a the rate of change of the pitch angle and to generate the compensated pitch angle signal as a function of the rate of change of the pitch angle.

10. The circuit of claim 9, further comprising a rate function coupled to receive the indicated pitch angle signal, the rate function being structured to determine the rate of change of the pitch angle and to output a signal representative of the rate of change of the pitch angle.

11. The circuit of claim 10 wherein the compensation function is structured to increase the compensation of the pitch angle signal by a predetermined amount in response to an increase in the rate of change of the pitch angle.

12. The device of claim 11 wherein the pitch angle alert generating circuit is operational as a ground proximity warning system for aircraft, the device further comprising:

a processor operating the function of the comparator, the processor being further structured to receive each of

a radio altitude signal, a barometric signal,

a glide slope deviation signal, and

a position signal representing the global position of the aircraft,

the processor being further structured to operate warning logic for generating a warning signal in response to predetermined relationships between radio altitude signal, barometric altitude signal, the glide slope deviation signal, and the decreasing difference signal output by the comparator; and

condition logic means operatively connected to the warning logic and being further structured to receive the position signal and to vary one or more of the predetermined relationships as a function of the aircraft position relative to a predetermined warning location.

13. The device of claim 12 further comprising a prioritization mechanism structured to inhibit the pitch angle alert generating circuit when the warning logic is operated to generate a warning signal in response to an indication of one of a negative climb after take-off, an insufficient terrain clearance, an excessive sink rate, an excessive closure rate, and a below glide slope approach.

14. A pitch angle alerting device, comprising:

a means for receiving a signal representing indicated pitch angle and a signal representing a maximum threshold pitch angle;

a means for compensating the indicated pitch angle signal;

a means operatively connected to receive the compensated pitch angle signal and the threshold pitch angle signal for comparing and determining a minimum difference between the compensated and threshold pitch angle signals; and

a means operatively connected to the comparing and difference determining means for generating an advisory indication signal as a function of the difference between the compensated and threshold pitch angle signals approaching the minimum difference.

15. The device of claim 14, further comprising:

a means for determining a rate of change of the indicated pitch angle; and

wherein the means for compensating the pitch angle signal operates as a function of the rate of change of the indicated pitch angle.

16. The device of claim 14 wherein the comparing and difference determining means operates on one of the indicated pitch angle signal and the compensated pitch angle signal.

17. The device of claim 16, further comprising a means for selecting between the indicated pitch angle signal and the compensated pitch angle signal.

18. The device of claim 14, wherein:

the indicated pitch angle signal is a signal representing the pitch angle of a host aircraft;

the comparing and difference determining means further generating a difference signal representing the difference between the indicated and threshold pitch angle signals; and

further comprising;

a means for receiving signals representing flight parameters of the aircraft, the flight parameter signals including the pitch angle difference signal;

warning logic means operatively connected to receive the flight parameter signals for comparing the flight parameter signals and for generating a warning signal in response to predetermined relationships between selected flight parameter signals;

a source of position signals representing a position of the aircraft; and

condition logic means operationally connected to the warning logic means and to the source of position signals for varying the predetermined relationships when the aircraft is in a predetermined warning location.

19. The device of claim 18 wherein the warning logic means operates the comparing and difference determining means.

20. The device of claim 18, further comprising means for inhibiting the advisory indication signal as a function of the warning logic means generating a warning signal.

21. The device of claim 20 wherein the flight parameter signals further include each of a radio altitude signal, a barometric signal, and a glide slope deviation signal.

22. A method for generating a pitch angle alert, the method comprising:

receiving a signal representing indicated pitch angle and a signal representing a maximum threshold pitch angle;

compensating the indicated pitch angle signal;

comparing the compensated and maximum threshold pitch angle signals;

determining a difference between the compensated and maximum threshold pitch angle signals; and

generating an excessive pitch excursion advisory indication signal as a function of the difference between the compensated and maximum threshold pitch angle signals.

23. The method of claim 22, further comprising:

determining a rate of change of the indicated pitch angle; and

wherein compensating the indicated pitch angle signal includes compensating the indicated pitch angle signal as a function of the rate of change of the pitch angle.

24. The method of claim 22 wherein the comparing and the difference determining operations operate on one of the indicated pitch angle signal and the compensated pitch angle signal.

25. The method of claim 24, further comprising selecting between the indicated pitch angle signal and the compensated pitch angle signal for the comparing and the difference determining operations.

26. The method of claim 22, wherein the indicated pitch angle signal is a signal representing the pitch angle of a host aircraft, and further comprising:

generating a difference signal representing the difference between the compensated indicated and threshold pitch angle signals;

receiving signals representing flight parameters of the aircraft, the flight parameter signals including the pitch angle difference signal;

comparing the flight parameter signals; and

generating a warning signal in response to predetermined relationships between selected flight parameter signals.

27. The method of claim 26, further comprising suppressing the generating an advisory indication signal as a function of the predetermined relationships between selected flight parameter signals.

28. The method of claim 26, further comprising:

receiving position signals representing a position of the aircraft; and

varying the predetermined relationships when the aircraft is in a predetermined warning location.

29. The method of claim 26 wherein the flight parameter signals further include each of a radio altitude signal, a barometric signal, and a glide slope deviation signal.

30. A ground proximity warning system for aircraft, comprising:

a source of signals representing a plurality of aircraft flight parameters, the flight parameter signals including a signal representing an indicated pitch attitude of the aircraft;

warning logic means operatively connected to the source of flight parameter signals for comparing the flight parameter signals and compensating the indicated pitch attitude, the warning logic means generating in response to predetermined relationships between selected flight parameter signals one of a warning signal and an advisory alert signal that is representative of the compensated pitch attitude exceeding a programmed alert threshold;

a source of position signals representing the position of the aircraft; and

condition logic means operationally connected to the warning logic means and the source of position signals for varying the predetermined relationships when the aircraft is in a predetermined warning area.

31. The system of claim 30, further comprising means for determining whether the aircraft is in the predetermined area, the area determining means including:

means for first successively comparing one of a present longitude and latitude with a respective stored longitude or latitude representative data defining one of a respective longitude band or a latitude band in which the aircraft is located, and after the one longitude or latitude band has been defined, successively comparing the other of the present longitude or latitude with respective stored longitude or latitude representative data within the defined band to define the other of the longitude or latitude bands in which the aircraft is located, the latitude band and the longitude band defining a zone;

means for defining an area within the zone; and

means for determining whether the aircraft is within the area.

32. The system of claim 30, further comprising means for prioritization of the generating the warning signal and the advisory alert signal.

33. The system of claim 30 wherein:

the flight parameter signals further comprise a signal representing a rate of change of the indicated pitch angle signals, and

the warning logic means further comprises means for compensating the indicated pitch angle as a function of an increasing rate of change of the indicated pitch angle signals.

34. A ground proximity warning system for aircraft comprising:

a source of radio altitude signals;

a source of barometric signals;

a source of glide slope deviation signals;

a source of indicated pitch angle signals;

a source of position signals representing the position of the aircraft;

pitch angle compensating means operatively connected to the source of indicated pitch angle signals for generating a compensated pitch angle signal;

warning logic means operatively connected to the source of compensated pitch angle signals for generating a signal representing a difference between the compensated pitch angle signals and a maximum limit and responsively indicating that the compensated pitch attitude exceeds the maximum limit, the warning logic means further operatively connected to the sources of radio altitude signals, barometric altitude signals and glide slope deviation signals for generating a warning signal in response to predetermined relationships between the radio altitude signals, barometric altitude signals, glide slope deviation signals and the pitch angle difference signals; and

prioritization means operatively connected to the warning logic means for suppressing the warning signal generated in response to the pitch angle difference signals as a function of the predetermined relationships between the radio altitude signals, barometric altitude signals and glide slope deviation signals.

35. The system of claim 34, further comprising condition logic means operatively connected to the warning means and the source of position signals for varying one or more of the predetermined relationships when the aircraft is in a predetermined warning location.

36. The system of claim 34, further comprising means for determining whether a aircraft is located in a predetermined warning location, the location determining means comprising:

means for monitoring the present longitude and latitude of the aircraft;

means for storing data representative of predetermined latitudes, and for storing data representative of predetermined longitudes;

means responsive to signals representative of the present longitude and latitude of the aircraft for successively comparing one of the present longitude or latitude with the respective stored longitude or latitude representative data to define one of a longitude or latitude band in which the aircraft is located;

after the one of the longitude or latitude bands has been defined successively comparing the other of the present longitude or latitude with the respective stored longitude or latitude representative data within the defined band to define the other of the longitude or latitude band in which the aircraft is located;

means responsive to the comparisons for defining a zone within which the aircraft is located, the zone being defined by the intersection of the latitude band and the longitude band;

means for storing data representative of regions and areas within the zones; and

means for comparing the present latitude and the present longitude with the region and area representative data, and providing an indication when the aircraft is within a region or an area.

37. The system of claim 34 wherein the pitch angle compensating means further comprises means for compensating the indicated pitch angle signals as a function of a rate of change of the indicated pitch angle signals.