SYSTEM AND METHOD FOR DETERMINING AIRCRAFT HARD LANDING EVENTS FROM INERTIAL AND AIRCRAFT REFERENCE FRAME DATA

• US 20100114411A1
• Filed: 08/11/2009
• Published: 05/06/2010
• Est. Priority Date: 06/10/2005
• Status: Active Grant

• Current Assignee: Safran Landing Systems Canada Incorporated / Safran Systemes D'Atterrissage Canada Incorporated
• Original Assignee: Messier-Dowty Incorporated (Safran SA)
• Inventors: SCHMIDT, R. KYLE
• Granted Patent: US 8,446,294 B2
• Time in Patent Office: Days
• US Class Current: 701/16
• CPC Class Codes: B64C 25/001 Devices not provided for in the groups B64C25/02 - B64C25/68
• CPC Class Codes: B64D 2045/008 Devices for detecting or indicating hard landing
• CPC Class Codes: G05D 1/0066 for limitation of acceleration or stress

Abstract

This invention allows for the precise determination of an aircraft'"'"'s landing conditions and whether an aircraft has experienced a hard landing that exceeds the allowable design loads of the aircraft'"'"'s landing gear. The system comprises a computer that measures signals from an inertial measurement unit (IMU) at high data rates (e.g. 100 Hz) and also records signals from the aircraft avionics data bus. The computer compares the output from the inertial measurement unit'"'"'s accelerometers against at least one predetermined threshold parameter to determine whether the aircraft'"'"'s three dimensional landing deceleration is safely within the design allowances or other regulatory limitations, or whether the landing event needs further investigation.

Claims

1. A system for acquiring aircraft landing conditions comprising:

a plurality of acceleration sensors;

a plurality of gyroscopes selected from the group consisting of angle sensors and angular rate sensors, the plurality of acceleration sensors and gyroscopes being additional to any pre-existing aircraft components;

means for measuring and storing data from the acceleration sensors and the gyroscopes at high data rates coupled to each of the sensors;

means for measuring and storing data from the aircraft avionics bus; and

means for comparing the stored data from said acceleration sensors and gyroscopes with at least one predetermined threshold parameter that when exceeded indicates that the data received from the acceleration sensors, gyroscopes and aircraft avionics bus must be further analyzed to ascertain if a hard landing has taken place, the means for comparing the stored data being adapted to couple to said sensors and said aircraft avionics bus for receiving data therefrom.

2. The system according to claim 1, wherein the means for comparing further comprises an indicator for indicating when the data has exceeded the at least one threshold parameter.

3. The system according to claim 1, further comprising at least one additional data measurement for further analysis to increase the accuracy and redundancy of the system.

4. The system according to claim 3, wherein the at least one additional physical data measurement is obtained from at least one of a strain transducer located on the landing gear, a pressure transducer located on the landing gear shock strut and a shock strut position indicator located on the landing gear.

5. The system according to claim 1, wherein the means for comparing the stored data further comprises at least one secondary threshold parameter for comparison with the stored data, wherein if the at least one secondary threshold parameter is exceeded the indicator indicates that a hard landing has taken place.

6. The system according to claim 1, wherein the means for measuring and storing data from the acceleration sensors and the gyroscopes, the means for measuring and storing data from the aircraft avionics bus and the means for comparing the stored data are the same.

7. A system for identifying an aircraft hard landing comprising:

(a) a plurality of sensing units each comprising a plurality of gyroscopes selected from angle sensors and angular rate sensors and a plurality of acceleration sensors, the plurality of gyroscopes and acceleration sensors being additional to any pre-existing aircraft components; and

(b) a central processing unit coupled to the plurality of sensing units for receiving data therefrom.

8. The system according to claim 7, wherein the central processing unit is operable to process the data received from the plurality of sensing units and further includes data correlating to at least one threshold parameter for comparison with at least one of the data received from the plurality of sensing units and the processed data to identify when a hard landing has occurred.

9. The system according to claim 7, wherein the transmission of data between the processing unit and the plurality of sensing units is in one of the analog domain or the digital domain.

10. The system according to claim 7, wherein each sensing unit is located at a position selected from at least one of close proximity to the landing gear, close proximity to the mounting of the landing gear and coupled to the unsprung mass of the landing gear.

11. The system according to claim 7, wherein at least one sensing unit is coupled to the aircraft at a position adjacent to the aircraft nominal centre of gravity in a non-pressurized area.

12. A method for determining the occurrence of an aircraft hard landing event comprising the steps of:

(a) recording and processing data received from at least one inertial measurement unit;

(b) recording and processing data received from an aircraft avionic bus;

(c) comparing the processed data from the at least one inertial measurement unit to at least one predetermined threshold parameter; and

(d) analyzing the data from the at least one inertial measurement unit and the aircraft avionic data bus if the data from the at least one inertial measurement unit exceeds one of the at least one threshold parameters.

13. The method according to claim 12, wherein the recording of data from the at least one inertial measurement unit occurs at high data rates.

14. The method according to claims 12, wherein the at least one inertial measurement unit comprises at least one non pre-existing accelerometer and at least one non pre-existing gyroscope and the data recorded from the at least one inertial measurement unit is data from the at least one accelerometer and/or at least one gyroscope.

15. The method according to claim 12, wherein the recording of data from the at least one inertial measurement unit and the aircraft avionic bus is initiated by a predetermined recording event and is continuous until the detection of a predetermined landing event.