LIGHT DETECTION AND RANGING (LIDAR) ICE DETECTION SYSTEM

• US 20180321386A1
• Filed: 08/04/2017
• Published: 11/08/2018
• Est. Priority Date: 05/04/2017
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Bosetti, Cris K., Biel-Goebel, John J., Cates, Michael C., Blanton, W. Brendan, Paul, JR., Bernard P., Bernier, Ken L.
• Granted Patent: US 10,429,511 B2
• Time in Patent Office: Days
• CPC Class Codes: B64D 15/20 Means for detecting icing or initiating de-icing
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/87 Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/88 Lidar systems specially adapted for specific applications
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 17/95 for meteorological use
• CPC Class Codes: G01S 7/4802 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G01S 7/4808 Evaluating distance, position or velocity data
• CPC Class Codes: G01S 7/499 using polarisation effects
• CPC Class Codes: G08B 19/02 Alarm responsive to formation or anticipated formation of ice

Abstract

A Light Detecting and Ranging (LIDAR) based system detecting and quantifying ice accretions and shedding on an aircraft. This system can be used to detect ice, operate ice protection systems, and satisfy aircraft icing certification requirements. This system can also be used to determine the shape, thickness, type, and location of the ice accretions.

Claims

1. A detector, comprising:

one or more Light Detection and Ranging (LIDAR) devices on an aircraft, each of the LIDAR devices including a transmitter and a receiver, wherein;

each of the transmitters repetitively scan an aerodynamic surface on the aircraft using laser pulses, forming scattered laser pulses scattered from the aerodynamic surface,

each of the receivers receive the scattered laser pulses and output data comprising timing of the scattered laser pulses received in the receiver, and

temporal changes in coordinates of the aerodynamic surface, indicating a presence or absence of ice on the aerodynamic surface, are calculated from the output data.

2. The detector of claim 1, wherein:

the aerodynamic surface is the surface of a wing, the empennage, or rotor on the aircraft,

the LIDAR devices are coupled to a computer,

the computer calculates temporal changes in a thickness of the wing, the empennage, or the rotor from the temporal changes in the coordinates, and

the computer uses the temporal changes in the thickness to determine accumulation of the ice or shedding of the ice.

3. The detector of claim 1, wherein:

the transmitters scan the aerodynamic surface of a wing in one or more line patterns across cross sections of the wing; and

the computer uses one or more scanning speeds of the scan to measure distances between the cross sections.

4. The detector of claim 1, comprising two of the LIDAR devices, wherein:

one of the LIDAR devices is positioned to scan the aerodynamic surface comprising an upper surface of the wing and output the data used to determine the coordinates of the upper surface, and

another of the LIDAR devices is positioned to scan to the aerodynamic surface comprising a lower surface of the wing and output the data used to determine coordinates of the lower surface.

5. The detector of claim 1, wherein:

the LIDAR devices comprise a first LIDAR device, a second LIDAR device, a third LIDAR device, and a fourth LIDAR device,

the first LIDAR device scans the aerodynamic surface comprising an upper surface of the wing, wherein the timing outputted from the first LIDAR device is used to determine the coordinates of the upper surface in a first direction;

the second LIDAR device scans the upper surface of the wing, wherein the timing outputted from the second LIDAR device is used to determine the coordinates of the upper surface in a second direction;

the third LIDAR device scans the aerodynamic surface comprising a lower surface of the wing, wherein the timing outputted from the third LIDAR device is used to determine the coordinates of the lower surface in the first direction; and

the fourth LIDAR device scans the lower surface of the wing, wherein the timing outputted from the fourth LIDAR device is used to determine the coordinates of the lower surface in the second direction.

6. The detector of claim 1, wherein the LIDAR devices are housed in a wing fairing on the aircraft.

7. The detectors of claim 1, further comprising a computer coupled to the LIDAR devices, wherein:

the data comprises a data set outputted for each of the plurality of scans representing the coordinates at different times, and

for each of the data sets, the computer;

extracts a shape of the aerodynamic surface from the data set using a shape model;

determines one or more deformations in the shape due to flexing of the aerodynamic surface due to weight of the wing and/or pressure of airflow over the wing;

transforms the data set into common coordinates in a common reference frame using a transformation function, wherein;

the common reference frame comprises the aerodynamic surface without the deformations, and

the transformation function transforms the aerodynamic surface having the deformations into the aerodynamic surface without the deformations;

temporal changes in the common coordinates in the common reference frame are used to detect the presence of the absence or the ice.

8. The detector of claim 7, wherein the computer filters the data to remove data corresponding to obscurants.

9. The detector of claim 1, wherein the receiver further comprises a spectrum analyzer and/or polarization detector outputting information on an optical property of the laser pulses associated with a presence or absence of the ice.

10. The detector of claim 9, wherein the optical property is at least one property selected from polarization, intensity, chirp, frequency, and absorption of the laser pulses.

11. The detector of claim 1, wherein the LIDAR devices detect shedding of the ice from the aerodynamic surface.

12. The detector of claim 1 coupled to avionics, wherein:

the avionics reverts stall warning tables to normal, allowing the aircraft to fly under non-icing conditions after the detector alerts the ice has been shed from the aerodynamic surface.

13. A method for detecting accumulation or shedding of ice from aerodynamic surfaces on an aircraft, comprising:

providing one or more Light Detection and Ranging (LIDAR) devices on an aircraft, each of the LIDAR devices including a transmitter and a receiver;

repetitively scanning one or more aerodynamic surfaces on the aircraft using laser pulses transmitted from one or more of the transmitters, forming scattered laser pulses scattered from the aerodynamic surface,

receiving the scattered laser pulses in one or more of the receivers;

outputting data from the receivers comprising timing of the scattered laser pulses received in the receivers, and

calculating, from the data, temporal changes in coordinates of the aerodynamic surface that indicate accumulation of ice on the aerodynamic surfaces and/or shedding of the ice from the aerodynamic surfaces.

14. The method of claim 13, wherein the aerodynamic surfaces include a surface of a wing, the empennage, or rotor on the aircraft, the method further comprising:

calculating temporal changes in a thickness of the wing, the empennage, or the rotor from the temporal changes in the coordinates; and

using the temporal changes in the thickness to determine the accumulation or the shedding of the ice.

15. The method of claim 13, further comprising:

scanning the aerodynamic surfaces of a wing in one or more line patterns across cross sections of the wing and using one or more scanning speeds; and

using the one or more scanning speeds to measure distances between the cross sections.

16. The method of claim 13, wherein the LIDAR devices include a first LIDAR device and a second LIDAR device, the method further comprising:

positioning the first LIDAR device transmitting the laser pulses to the aerodynamic surface comprising an upper surface of the wing, wherein the timing outputted from the first LIDAR device is used to determine the coordinates of the upper surface; and

positioning the second LIDAR device transmitting the laser pulses to the aerodynamic surface comprising a lower surface of the wing, wherein the timing outputted from the second LIDAR device is used to determine the coordinates of the lower surface.

17. The method of claim 13, wherein the LIDAR devices comprise a first LIDAR device, a second LIDAR device, a third LIDAR device, and a fourth LIDAR device, the method further comprising:

positioning the first LIDAR device transmitting the laser pulses to the aerodynamic surface comprising an upper surface of the wing, wherein the timing outputted from the first LIDAR device is used to determine the coordinates of the upper surface in a first direction;

positioning the second LIDAR device transmitting the laser pulses to the upper surface of the wing, wherein the timing outputted from the second LIDAR device is used to determine the coordinates of the upper surface in a second direction;

positioning the third LIDAR device transmitting the laser pulses to the aerodynamic surface comprising a lower surface of the wing, wherein the timing outputted from the third LIDAR device is used to determine the coordinates of the lower surface in the first direction; and

positioning the fourth LIDAR device transmitting the laser pulses to the lower surface of the wing, wherein the timing outputted from the fourth LIDAR device is used to determine the coordinates of the lower surface in the second direction.

18. The method of claim 13, further comprising:

receiving the data comprising a data set outputted for each of the plurality of scans and representing the coordinates of one of the aerodynamic surfaces at different times,

for each of the data sets;

extracting a shape of the aerodynamic surface from the data set using a shape model;

determining one or more deformations in the shape due to flexing of the aerodynamic surface;

transforming the data set into coordinates in a common reference frame using a transformation function, wherein;

the common reference frame comprises the aerodynamic surface without the deformations, and

the transformation function transforms the aerodynamic surface having the deformations into the aerodynamic surface without the deformations;

detecting the accumulation or the shedding of ice on the aerodynamic surface using temporal changes in the coordinates in the common reference frame.

19. The method of claim 13, wherein the data further comprises information on an optical property of the laser pulses, the method further comprising using the optical property to detect the accumulation or the shedding of the ice.

20. The method of claim 13, further comprising alerting avionics when the detector indicates ice has been shed from the aerodynamic surfaces so that the avionics reverts stall warning tables to normal and allows the aircraft to fly under non-icing conditions.