A method for monitoring the thickness of aircraft ice

Abstract

The present invention relates to the field of aerospace technology, and in particular to a method for monitoring the thickness of ice on an aircraft. The method comprises: emitting a laser from within the aircraft skin, the laser passing through a laser transmission and reflection layer embedded flat in the aircraft skin layer; receiving the position of the laser reflected from the inner surface of the laser transmission and reflection layer back to the aircraft skin on a receiving surface, and marking the position as a first position; if there is no ice on the aircraft surface, the laser enters the atmosphere after being emitted from the laser transmission and reflection layer, and will not return to the aircraft skin; if there is ice on the aircraft surface, the laser refracts into the ice after being emitted from the laser transmission and reflection layer, and is reflected at the interface between the ice and the air, and the reflected laser returns to the aircraft skin via the ice and the laser transmission and reflection layer, and the reflected laser is received on the receiving surface and the second position of the reflected laser is recorded; the thickness of the ice is determined according to the distance between the first position and the second position. The method for monitoring the thickness of ice on an aircraft provided by the present invention can monitor the thickness of ice on an aircraft.

Description

Technical Field

[0001] The invention relates to the field of aerospace technology, and in particular to a method for monitoring the thickness of ice on an aircraft. Background Art

[0002] Aircraft icing seriously affects flight safety. Existing icing sensors can only be set on the outer surface of the aircraft for monitoring, which will affect the aerodynamics of the aircraft. Summary of the invention

[0003] The embodiment of the present invention provides a method for monitoring the thickness of ice on an aircraft, which can monitor the thickness of ice on the aircraft inside the aircraft.

[0004] An embodiment of the present invention provides a method for monitoring ice thickness of an aircraft, comprising:

[0005] The laser is emitted from the aircraft skin and passes through the laser transmission and reflection layer embedded flat in the aircraft skin layer;

[0006] The position where the laser reflected from the inner surface of the laser transmission and reflection layer back to the inside of the aircraft skin is received on the receiving surface, and the position is marked as a first position;

[0007] If there is no ice layer on the aircraft surface, the laser will enter the atmosphere after being emitted from the laser transmission and reflection layer, and will not return to the aircraft skin;

[0008] If there is an ice layer on the aircraft surface, the laser is refracted into the ice layer after being emitted from the laser transmission and reflection layer, and is reflected at the interface between the ice layer and the air. The reflected laser returns to the aircraft skin via the ice layer and the laser transmission and reflection layer, and the reflected laser is received on the receiving surface and the second position of the reflected laser is recorded.

[0009] The thickness of the ice layer is determined based on the distance between the first position and the second position.

[0010] In a possible design, the laser transmissive reflective layer includes tempered glass.

[0011] In a possible design, the laser is emitted from the aircraft skin, and the laser passes through a laser transmission and reflection layer flatly embedded in the aircraft skin layer, including:

[0012] Multiple laser beams are emitted from the aircraft skin, and each laser beam passes through a laser transmission and reflection layer flatly embedded in the aircraft skin layer;

[0013] The step of determining the thickness of the ice layer according to the distance between the first position and the second position comprises:

[0014] Each laser beam obtains the first position and the second position, and calculates the distance between the first position and the second position;

[0015] The thickness of the ice layer is calculated based on the plurality of distances.

[0016] In one possible design, multiple laser beams are parallel to each other and arranged in an array with equal spacing.

[0017] In one possible design, it also includes:

[0018] The receiving surface collects the intensity of the reflected laser at the second position;

[0019] The thickness of the ice layer is determined according to the intensity of the reflected laser light at the second position.

[0020] In a possible design, the wavelength of the laser is 900-1000 nm.

[0021] In a possible design, the wavelength of the laser is 300-600 nm.

[0022] In one possible design, it also includes:

[0023] The angle of the laser is adjusted so that the propagation angle of the laser in the ice layer is greater than or equal to the critical angle for the laser to emit total reflection at the ice-air interface.

[0024] In a possible design, laser light is generated by a laser transmitter, a laser emitting end of the laser transmitter is closely attached to or embedded in the laser transmission and reflection layer, and the receiving surface is closely attached to or embedded in the laser transmission and reflection layer.

[0025] In a possible design, the thickness of the ice layer is calculated by the following formula:

[0026] h=[a×nk×sin(wk)×cos(wb)] / (2×nb)

[0027] Wherein, h is the thickness of the ice layer, a is the distance between the first position and the second position, nk is the refractive index of the laser transmission and reflection layer, wk is the incident angle of the laser entering the ice layer from the laser transmission and reflection layer, wb is the refractive angle of the laser entering the ice layer from the laser transmission and reflection layer, and nb is the refractive index of the ice layer.

[0028] Compared with the prior art, the present invention has at least the following beneficial effects:

[0029] In this embodiment, the laser is incident at a certain angle and passes through the laser transmission and reflection layer, and is reflected at the upper interface of the laser transmission and reflection layer. The reflected laser is received on the receiving surface, and the position of the reflected laser on the receiving surface is marked as the first position. If there is no ice layer on the surface of the aircraft, the laser emitted from the laser transmission and reflection layer will not be reflected back; if there is ice layer on the surface of the aircraft, the laser will enter the ice layer, and then reflect again at the upper interface of the ice layer. The light reflected from the upper interface of the ice layer is incident on the receiving surface, and the position of the reflected light is marked as the second position. The thicker the ice layer, the greater the distance between the first position and the second position, and the thickness of the ice layer can be determined by the distance between the first position and the second position. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 is a flow chart of a method for monitoring ice thickness on an aircraft provided by an embodiment of the present invention;

[0032] Figure 2 It is a schematic diagram of a laser light path provided by an embodiment of the present invention.

[0033] In the figure:

[0034] 1-Laser;

[0035] 2-Laser transmission reflection layer;

[0036] 3-Ice layer;

[0037] A - first position;

[0038] B - Second position. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; unless otherwise specified or explained, the term "multiple" refers to two or more; the terms "connected" and "fixed" should be understood in a broad sense, for example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In the description of this specification, it should be understood that the directional words such as "upper" and "lower" described in the embodiments of the present invention are described at the angles shown in the drawings and should not be understood as limiting the embodiments of the present invention. In addition, in the context, it should also be understood that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element.

[0042] Please refer to Figure 1 and Figure 2 The embodiment of the present invention provides a method for monitoring ice thickness of an aircraft, comprising:

[0043] The laser is emitted from the aircraft skin and passes through the laser transmission and reflection layer embedded flat in the aircraft skin layer;

[0044] The position where the laser reflected from the inner surface of the laser transmission reflection layer back to the inside of the aircraft skin is received on the receiving surface, and the position is marked as a first position;

[0045] If there is no ice on the aircraft surface, the laser will enter the atmosphere after being emitted from the laser transmission and reflection layer and will not return to the aircraft skin;

[0046] If there is ice on the aircraft surface, the laser is refracted into the ice layer after being emitted from the laser transmission and reflection layer, and is reflected at the interface between the ice layer and the air. The reflected laser returns to the aircraft skin via the ice layer and the laser transmission and reflection layer, and the reflected laser is received on the receiving surface and the second position of the reflected laser is recorded.

[0047] The thickness of the ice layer is determined based on the distance between the first location and the second location.

[0048] In this embodiment, the laser is incident at a certain angle and passes through the laser transmission and reflection layer, and is reflected at the upper interface of the laser transmission and reflection layer. The reflected laser is received on the receiving surface, and the position of the reflected laser on the receiving surface is marked as the first position. If there is no ice layer on the surface of the aircraft, the laser emitted from the laser transmission and reflection layer will not be reflected back; if there is ice layer on the surface of the aircraft, the laser will enter the ice layer, and then reflect again at the upper interface of the ice layer. The light reflected from the upper interface of the ice layer is incident on the receiving surface, and the position of the reflected light is marked as the second position. The thicker the ice layer, the greater the distance between the first position and the second position, and the thickness of the ice layer can be determined by the distance between the first position and the second position.

[0049] Each functional component in the monitoring method provided in the present application is embedded in the skin or located below the skin, and will not affect the appearance of the fuselage, nor will it affect the aerodynamics of the fuselage.

[0050] In some embodiments of the present invention, the laser transmissive reflective layer comprises tempered glass.

[0051] In this embodiment, the tempered glass has higher strength, higher flatness and excellent light transmission performance.

[0052] In some embodiments of the present invention, a laser is emitted from within the aircraft skin, and the laser passes through a laser transmission and reflection layer flatly embedded in the aircraft skin layer, including:

[0053] Multiple laser beams are emitted from the aircraft skin, and each laser beam passes through a laser transmission and reflection layer flatly embedded in the aircraft skin layer;

[0054] Determining the thickness of the ice layer based on the distance between the first location and the second location includes:

[0055] Each laser beam obtains a first position and a second position, and calculates the distance between the first position and the second position;

[0056] Calculate the thickness of ice based on multiple distances.

[0057] There may be some depressions or protrusions on the upper interface of the ice layer. If the laser is incident on these depressions or protrusions, it will cause a large error in the thickness data. In order to improve the accuracy, multiple laser beams are set to obtain the distances between multiple first positions and second positions. These distances are analyzed, extremely high or extremely low values ​​are removed, and then the remaining data are averaged. In this way, more accurate thickness data can be obtained.

[0058] It should be noted that multiple lasers do not need to use a laser transmission and reflection layer with a larger area, but only need to be set in the area where the laser path may pass through.

[0059] In some embodiments of the present invention, multiple laser beams are parallel to each other and arranged in an array with the same spacing, so that more comprehensive and uniform data can be obtained.

[0060] In some embodiments of the present invention, it further includes:

[0061] The receiving surface collects the intensity of the reflected laser at the second position;

[0062] The thickness of the ice layer is determined based on the intensity of the reflected laser light at the second position.

[0063] In this embodiment, the intensity of the reflected laser at the second position is recorded. Part of the energy of the laser will be absorbed by the ice layer during the propagation of the laser in the ice layer. The thicker the ice layer, the longer the propagation path of the laser in the ice layer, and the weaker the intensity of the reflected laser at the second position. Therefore, the thickness of the ice layer can be judged by the intensity of the reflected laser.

[0064] In some embodiments of the present invention, the wavelength of the laser is 900-1000 nm.

[0065] In this embodiment, the long-wave laser has good penetration and is more easily absorbed by the ice layer, which can improve the sensitivity of the height change of the ice layer. The wavelength of the long-wave laser is 900~1000nm. With this setting, the laser is more easily absorbed by the ice.

[0066] In some embodiments of the present invention, the wavelength of the laser is 300-600 nm.

[0067] In this embodiment, the short-wave laser is not easily emitted, has excellent directivity, and is easy to form a good reflection light spot on the receiving surface. The wavelength of the short-wave laser is 300~600nm. The short-wave laser within the above wavelength range is more easily reflected by ice.

[0068] In some embodiments of the present invention, it further includes:

[0069] The angle of the laser is adjusted so that the propagation angle of the laser in the ice layer is greater than or equal to the critical angle for the laser to emit total reflection at the ice-air interface.

[0070] In this embodiment, by controlling the angle of the laser, the laser is totally reflected when it enters the air from the ice layer, and then all the laser is reflected back, reducing the loss of laser intensity and making it easier for the receiving surface to receive it.

[0071] In some embodiments of the present invention, laser light is generated by a laser transmitter, a laser emitting end of the laser transmitter is closely attached to or embedded in the laser transmission and reflection layer, and a receiving surface is closely attached to or embedded in the laser transmission and reflection layer.

[0072] In some embodiments of the present invention, the thickness of the ice layer is calculated by the following formula:

[0073] h=[a×nk×sin(wk)×cos(wb)] / (2×nb)

[0074] Wherein, h is the thickness of the ice layer, a is the distance between the first position and the second position, nk is the refractive index of the laser transmission and reflection layer, wk is the incident angle of the laser entering the ice layer from the laser transmission and reflection layer, wb is the refractive angle of the laser entering the ice layer from the laser transmission and reflection layer, and nb is the refractive index of the ice layer.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for monitoring the thickness of ice on an aircraft, It is characterized in that include: The laser is emitted from the aircraft skin and passes through the laser transmission and reflection layer embedded flat in the aircraft skin layer; The position where the laser reflected from the inner surface of the laser transmission and reflection layer back to the inside of the aircraft skin is received on the receiving surface, and the position is marked as a first position; If there is no ice layer on the aircraft surface, the laser will enter the atmosphere after being emitted from the laser transmission and reflection layer, and will not return to the aircraft skin; If there is an ice layer on the aircraft surface, the laser is refracted into the ice layer after being emitted from the laser transmission and reflection layer, and is reflected at the interface between the ice layer and the air. The reflected laser returns to the aircraft skin via the ice layer and the laser transmission and reflection layer, and the reflected laser is received on the receiving surface and the second position of the reflected laser is recorded. determining a thickness of the ice layer based on a distance between the first location and the second location; Also includes: The receiving surface collects the intensity of the reflected laser at the second position; determining the thickness of the ice layer according to the intensity of the reflected laser light at the second position; The wavelength of the laser is 900-1000nm; The laser is generated by a laser transmitter, the laser emitting end of the laser transmitter is closely attached to or embedded in the laser transmission and reflection layer, and the receiving surface is closely attached to or embedded in the laser transmission and reflection layer; The thickness of the ice layer is calculated by the following formula: h=[a×nk×sin(wk)×cos(wb)] / (2×nb) Wherein, h is the thickness of the ice layer, a is the distance between the first position and the second position, nk is the refractive index of the laser transmission and reflection layer, wk is the incident angle of the laser entering the ice layer from the laser transmission and reflection layer, wb is the refractive angle of the laser entering the ice layer from the laser transmission and reflection layer, and nb is the refractive index of the ice layer; Also includes: Adjust the angle of the laser so that the propagation angle of the laser in the ice layer is greater than or equal to the critical angle for the laser to emit total reflection at the ice-air interface; The laser transmission and reflection layer comprises tempered glass; The laser is emitted from the aircraft skin, and the laser passes through a laser transmission and reflection layer flatly embedded in the aircraft skin layer, including: Multiple laser beams are emitted from the aircraft skin, and each laser beam passes through a laser transmission and reflection layer flatly embedded in the aircraft skin layer; The step of determining the thickness of the ice layer according to the distance between the first position and the second position comprises: Each laser beam obtains the first position and the second position, and calculates the distance between the first position and the second position; The thickness of the ice layer is calculated based on the plurality of distances.

2. The monitoring method according to claim 1, It is characterized in that Multiple laser beams are parallel to each other and distributed in an array with the same spacing.

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