RU2133973C1 - Method of illumination of instrument panel and lighted signs of aircraft when viewed through pilot's night-vision goggles - Google Patents

Abstract

FIELD: piloting aircraft under night and complex meteorological conditions with usage by crew of pilot's night-vision goggles based electron-optical converters . SUBSTANCE: method of illumination of instrument panel and lighted signs with usage by crew of pilot's night-vision goggles includes formation of optical radiation flux, change of spectral composition of optical radiation flux, transfer of obtained optical radiation flux to plane of instrument panel and lighted signs of aircraft, subsequent transfer of flux to planes of entrance pupils of pilot's night-vision goggles, transfer of optical radiation flux after amplification to planes, of entrance pupils of eyes of crew, change of spectral composition of optical radiation flux to color gamma corresponding to color gamma of equipment of aircraft and facilitating creation of minimal illumination of pilot's night-vision goggles, transfer of optical radiation flux to plane of entrance pupils of pilot's night-vision goggles, new change of spectral composition of optical radiation flux so that optical radiation flux twice altered by spectrum forms photocathode current of pilot's night-vision goggles not exceeding threshold level of formation of haloes. EFFECT: increased operating range of pilot's night-vision goggles, improved perception of flight information and light signalling by crew through these goggles. 13 dwg

Description

 The invention is intended to illuminate instrumentation equipment and light-signaling banners of aircraft and can be used for flying aircraft in night and difficult weather conditions when the crew uses night vision goggles (ONV) based on electron-optical converters (EOP).

 A known method of illuminating instrumentation equipment and light signaling banners of aircraft using night vision goggles by the crew, including generating an optical radiation flux, changing the spectral composition of the optical radiation flux corresponding to the “red” region of the spectrum at the color locus, transferring the obtained optical radiation flux to the instrument plane equipment and light signaling of the aircraft and the subsequent transfer of flow in the plane of the input of night vision goggles, and after increasing the flow of optical radiation, transferring it to the plane of the entrance pupils of the crew’s eyes (Mi-8 helicopter. Technical description. Book IV. Aviation equipment. - M.: "Engineering", 1972 and Mi-24D helicopter. Technical description, Book IV. Aviation equipment. - M .: "Engineering", 1983).

 The disadvantage of this method of lighting instrumentation and light signaling, the spectral composition of which corresponds to the "red" region of the spectrum at the color locus (Fig. 1) (Optoelectronic devices for scientific research. Textbook / L.A. Novitsky, A.S. Gomenyuk, V.E. Zubarev, A.M. Khorokhorov. - M.: Mashinostroenie, 1986. - 432 pp. Ill.), There is a sharp decrease in the range of night vision goggles and the lack of perception by the crew of aircraft of navigation and navigation information and light signal analysis through aerobatic night vision goggles due to the powerful background illumination of the image intensifier photocathode, which has maximum sensitivity in the “red” and near IR spectral regions (Fig. 2).

 Two main factors limit the application of this technical solution.

 1. Due to the high sensitivity of the photocathodes of the image intensifier tubes (in particular, generation III image intensifiers exceeding 1500 μA / lm) powerful “halos” are formed around the images of point sources larger than 0.1 mm; Jim Malloy. Military Night Vision - 2000 and beyond. - Abstracts of the IV International Conference "Night Vision -96", London, September 3 - 4, 1996).

 2. Background illumination created by the flow of "red" optical radiation from the lighting of instrumentation and light signaling, located in the immediate vicinity of the crew of the aircraft using night vision goggles.

The occurrence of power background illumination and the presence of "ghosting" around the image leads
1. To the loss of contrast in the image of the enclosed space, as a result of which there is a sharp decrease in the range of detection and recognition of objects;
2. The deterioration or disappearance of the images of the readings of instrumentation and signaling equipment (Figs. 3 and 4), as a result of which the crew is forced to abandon the use of aerobatic night vision goggles.

 A known method of lighting instrumentation and light signaling of aircraft when the crew uses flight goggles of night vision, including the formation of an optical radiation flux, changing the spectral composition of the optical radiation flux corresponding to the "green" region of the spectrum at the color locus and the absence of a wavelength of 640-930 nm in the emission spectrum transferring the received stream of optical radiation to the plane of instrumentation and light signaling of the aircraft and subsequent transfer os flow in the plane of the entrance pupils of the night vision goggles, and after amplification of the optical radiation flux, transfer it to the plane of the entrance pupils of the crew’s eyes (Recommendations R 1.1.16-93. Requirements for the inside cabin lighting with green light and light signaling of helicopters when using night vision goggles. / On 7 pages /).

 The disadvantage of this method of lighting instrumentation and light signaling, the spectral composition of which corresponds only to the "green" region of the spectrum, and the color locus (Fig. 1), as well as the absence in the emission spectrum in the wavelength range of 630-900 nm (this condition is devoid of physical meaning , since it is practically impossible to carry out absolute spectral filtering, reducing the level of optical radiation flux to zero; when performing spectral filtering, as a rule, the level of the residual optical radiation flux is set ia), there is a sharp decrease in the range of night vision goggles and the inability of the crew to perceive flight and navigation information and light signaling through night vision goggles, due to the powerful background illumination of the image intensifier tube sensitive from the blue to the near infrared region of the spectrum ( Fig. 2).

 Two main factors limit the application of this technical solution.

1. Due to the high sensitivity of the photocathodes and the sufficiently large conversion coefficient of the image intensifier tubes (in particular, the generation III image intensifier has a sensitivity greater than 1500 μA / lm, and the conversion coefficient exceeds 25000), powerful “halos” are formed around the image of point sources larger than 0.1 mm images, the size of which with III-generation image intensifiers should not exceed 1.25 mm (Jim Malloy. Military Night Vision - 2000 and beyond. - Abstracts at the IV International Conference "Night Vision-96, London, September 3-4 3-4, 1996);
2. Background illumination created by the flow of "green" optical radiation from the illumination of instrumentation and light signaling located in the immediate vicinity of the crew of the aircraft using night vision goggles.

Although this technical solution provides spectral filtering in the "red" and near-IR spectral regions, but because of the high sensitivity of the image intensifier photocathodes from the "blue" to the near-IR spectral regions, background illumination also appears and smaller "halos" appear around the image that leads
1. The loss of contrast in the image of the enclosed space, as a result of which there is a sharp decrease in the range of detection and recognition of objects;
2. To a sharp decrease in the contrast of the image of the readings of the instrument and signal equipment or to its complete loss at high spatial frequencies (Figs. 5 and 6), as a result of which the crew is forced to abandon the use of night vision goggles.

 The proposed invention is aimed at solving the technical problem of increasing the range of night vision goggles while ensuring the ability to perceive flight and navigation information and light signaling by the crew through night vision goggles.

 The technical result obtained by using the invention is to increase the reliability of piloting and to ensure the flight safety of the aircraft, namely, while maintaining the psycho-physiological requirements for display, i.e. the possibility of perception when the crew uses night vision goggles of the necessary color gamut (green, red, yellow) of information displays, panels and indicators of instrumentation located in the cockpit, at the same time limit the spectral characteristics of the glasses in the short-wavelength region so that the optical radiation flux corrected by spectral filters, did not exceed the threshold level of formation of "ghosting".

 The technical result is achieved by the fact that in the method of lighting instrument equipment and light signaling of an aircraft when the crew uses night vision goggles, including generating an optical radiation flux, changing the spectral composition of the optical radiation flux, transferring the obtained optical radiation flux to the plane of the instrumentation and light signaling of the aircraft apparatus and the subsequent transfer of flow in the plane of the entrance pupils of night vision goggles, and after amplification of the optical radiation flux, transferring it in the plane of the entrance pupils of the crew’s eyes changes the spectral composition of the optical radiation flux to the color gamut corresponding to the color gamut of the aircraft’s equipment, and then, after transferring the optical radiation flux to the plane of the entrance pupils of night vision goggles, change the spectral composition of the optical radiation flux in such a way that the twice-changed optical flux of the optical radiation generates a flight photocathode current x night vision goggles not exceeding the threshold level of formation of "ghosting".

The invention is illustrated in graphic materials, where
in FIG. Figure 1 shows a spectral locus with regions of acceptable colors for illuminating in-cab equipment adapted to NVG;
in FIG. Figure 2 shows typical spectral characteristics of the relative sensitivity of a third-generation image intensifier tube (Class A and Class B) and a second generation image intensifier tube;
in FIG. 3 - shows a photograph of a standard dashboard of a helicopter under illumination with a red backlight system;
in FIG. 4 is an image of a given fragment of the dashboard of a helicopter, observed through ONV;
in FIG. 5 is a photograph of a standard dashboard of a helicopter illuminated by a green backlight system;
in FIG. 6 - image of this fragment of the dashboard of the helicopter, observed through ONV;
in FIG. 7 is an optical diagram of a device that implements the proposed method;
in FIG. 8 is a spectral characteristic of a cut-off filter λ _from = 665 nm) for a Class B BLL;
in FIG. 9 - spectral characteristics of the night sky radiation and reflection coefficient of underlying backgrounds and typical targets;
in FIG. 10 - spectral density of the energy brightness of the light component with a visual brightness of L = 3 Cd / m • m;
in FIG. 11 is a spectral transmission characteristic of a filter Green A;
in FIG. 12 is a photograph of a fragment of a standard dashboard of a helicopter in combination, made in accordance with this invention;
in FIG. 13 is an image of this fragment of the dashboard of a helicopter, observed through ONV.

 The proposed method can be implemented in a device, the optical circuit of which is shown in FIG. 7.

 The device contains signal external lighting equipment 1, in-cab signal boards and panels 2, control panels 3, in-cab instrument equipment 4, optical radiation sources 5 that are part of the aircraft, transparencies with the corresponding test or sign recording 6, spectral filters: “green” 7 , "yellow" 8 and "red" 9, night vision goggles 11 used by the crew of the aircraft, containing cut-off spectral filters 10 and electron-optical converters Teli (EOC) 12, on the basis of which created aerobatic night-vision goggles, the indicators instrumentation 13, publicized through the "green" spectral filters 7.

 A device that implements the proposed method works as follows.

 Sources of optical radiation 5.

1. Through spectral filters: "green" 7, "yellow" 8 and "red" 9 illuminate the corresponding signal external lighting equipment 1;
2. Through spectral filters: “green” 7, “yellow” 8 and “red" 9 illuminate, in accordance with the requirements for lighting equipment of the aircraft, banners 6 of the signal boards of the control panels 2, control panels 3, with the corresponding text or graphic record;
3. Also through the "green" spectral filter 7 illuminate the indicators of the instrumentation 13.

 The optical radiation fluxes changed in the spectrum fall in the plane of the entrance pupils of the night vision goggles 11, passing through the cut-off spectral filters 10, acquire such a spectral composition that the optical emission flux twice in the spectrum forms the photocathode current of the image intensifier tube 12 night vision goggles 11, not exceeding the threshold level of formation of "ghosting".

 To complete the task, the aircraft crew must control the aircraft with visual control of the instrument readings installed on the instrument boards, remote controls of the helicopter cockpit and carry out visual observation of the cockpit space. To control the aircraft, it is equipped with signaling external lighting equipment 1 (drill lights, airborne navigation lights, etc.), and a large number of signal boards and remotes 2, control panels 3 and other in-cab instrumentation 4 are installed in the cockpit.

 For the practical implementation of the possibility of piloting an aircraft at night using aerobatic night vision goggles, it is necessary to change the spectral composition of lighting of lighting equipment and light signaling in such a way as to satisfy the psycho-physiological requirements for indication (green color - informational, yellow color - attention, red color - danger), i.e. maintain the color gamut of information displays, panels and indicators of instrumentation located in the cockpit and at the same time ensure flight safety conditions. To do this, spectral filters are installed in the lighting fixtures of the signal external lighting equipment 1: green 7, yellow 8 and red 9, and in the lighting fixtures of signal boards and panels 2 and control panels 3 between the optical radiation sources 5 and transparencies 6 spectral filters are installed with the corresponding text or sign-graphic recording: “green” 7, “yellow” 8 and “red” 9, and also for illuminating the indicators of instrumentation 13, between the optical radiation source 5 ind ikatorov instrumentation equipment 13 installed spectral "green" filters 7, creating minimal "background" illumination aerobatic night vision goggles.

However, such an adjustment, when the "red" backlight (Fig. 3 and 4) of instrumentation and light signaling of aircraft (Mi-8 helicopter. Technical description. Book IV. Aviation equipment. - M .: "Engineering", 1972 and Mi Helicopter -24D. Technical description. Book IV. Aviation equipment. - M.: "Engineering", 1983) was replaced by "green-yellow-red" without special requirements for the spectral characteristics of "color filters" (Fig. 5 and 6) (Recommendations R 1.1.16-93. Requirements for indoor lighting green . Th and light signaling helicopters using night vision goggles / For 7 pages /), does not lead to the desired result - the elimination of backlight and "halos" around the image or text znakograficheskoy information. This is due to the fact that a typical spectral characteristic of the photocathode of the image intensifier tube extends into the short-wavelength region of the spectrum up to 450 nm (Fig. 2). Even the typical spectral characteristic of the photocathodes of III generation ICs extends to the short-wavelength region of the spectrum up to 450 nm. (Fig. 2) at the level of 10 ^-2 . ..10 ^-4 of the maximum value. Therefore, with the high sensitivity of the photocathodes and a sufficiently large conversion coefficient of the image intensifier tube, the optical radiation flux corrected by spectral filters 7 or 8 or 9 is sufficient to create background illumination and “ghosting” in the images formed by night vision flight goggles.

 For the practical implementation of the possibility of piloting the aircraft at night using aerobatic night vision goggles, it is necessary to further limit the spectral characteristics of the goggles in the short-wavelength region so that the optical radiation flux corrected by spectral filters 7 or 8 or 9 does not exceed the threshold level for the formation of “halos” . For this purpose, in addition to specifying special requirements for the spectral characteristics of filters 7, 8 and 9, a cut-off spectral filter 10 is additionally installed in the plane of the entrance pupils of the night vision goggles 11, the transmission spectral characteristic of which is shown in FIG. eight.

On the expediency of limiting the spectral characteristics of glasses in the short-wavelength region, in accordance with the spectral transmission characteristic shown in FIG. 8, indicate two factors:
- on a moonless night, the maximum spectral brightness (M _rel ) of the night sky is in the spectral region (900 - 1000) nm, and in the spectral region (450 - 650) nm the spectral brightness of the night sky is low (Fig. 9). Moreover, this spectral region (450 - 650) nm is the contrast inversion region of most artificial objects against the background of vegetation (Fig. 9);
- in the spectral region (650 - 900) nm, the spectral brightness of optical radiation due to the scattering of optical radiation by vegetation (green leaf, grass, etc.) increases significantly (Fig. 9). Moreover, in this spectral region, the contrast of most artificial objects (tanks, infantry fighting vehicles, automobiles, etc.) against the background of vegetation significantly exceeds the contrast in the spectral region (450 - 650) nm (Fig. 9).

 In particular, with practically no reduction in the range of ONV on the III generation image intensifier, it is possible to limit the spectral characteristic of glasses in the short-wave region of the spectrum with a wavelength of 625 nm. At the same time, due to the elimination of the powerful background illumination of IT from lighting equipment and light signaling by means of its double spectral filtering, it is possible to increase the range of the ONV.

 An example implementation of the claimed method.

 The given example of calculating color coordinates, as well as the level of ghosting, which is the main criterion for compatibility of instrument lighting and light signaling of aircraft with aerobatic night vision goggles, is based on data obtained by measuring one of the components of the lighting system of a MI helicopter to use with aerobatic night vision goggles based on a third generation image intensifier tube.

 The values of the chromaticity coordinates (U 'and V') and also the level of formation of "ghosting" obtained by calculation for this example are applicable only for this particular component of the lighting system of a MI helicopter.

A.1. Calculation of surface current density I _FC photocathode
In FIG. 10 is a graph of the spectral density of the energy brightness of a radiation source with a temperature of T = 2000 K behind a green filter, which has a brightness L _v = 3 Kd / m ² behind this filter. In FIG. 2 shows a graph of the normalized spectral sensitivity of the image intensifier tube S _rel (λ), and the spectral transmission characteristics of the cut-off filter τ _of (λ) and the green filter τ _sf (λ) are shown in FIG. 8 and 11.

где τ_оф(λ) - - спектральная характеристика пропускания отрезающего фильтра,
S_фк(λ) = S_max•S_отн(λ) - спектральная чувствительность фотокатода ЭОП,
S_max - максимальное значение спектральной чувствительности ЭОП,
S_отн(λ) - нормированная спектральная чувствительность ЭОП,

- спектральная характеристика энергетической освещенности в плоскости фотокатода,
τ_об - коэффициент пропускания входного объектива ОНВ,

- относительное отверстие входного объектива ОНВ,
L(λ) = L_max•R(λ,T) - спектральная плотность энергетической яркости источника излучения с температурой T за зеленым фильтром, имеющего за этим фильтром яркость L_V.Consider the example of calculating the surface current density I _FC photocathode occurs when illumination image intensifier according to formula (1):

where τ _of (λ) - is the spectral transmission characteristic of the cut-off filter,
S _fc (λ) = S _max • S _rel (λ) is the spectral sensitivity of the photocathode of the image intensifier tube,
S _max - the maximum value of the spectral sensitivity of the image intensifier,
S _rel (λ) is the normalized spectral sensitivity of the image intensifier,

- spectral characteristic of the energy illumination in the plane of the photocathode,
τ _about - transmittance of the input lens ONV,

- relative hole of the input lens ONV,
L (λ) = L _max • R (λ, T) is the spectral density of the energy brightness of a radiation source with a temperature T behind a green filter having a brightness L _V behind this filter.

- нормировочный коэффициент, приводящий спектральную плотность энергетической яркости к заданному уровню яркости L_V,
K(λ) = (683 лм/Вт)•V(λ),
V(λ) - относительная видность излучения в условиях дневного зрения по данным МКО,
R(λ,T) = L_отн(λ,T)•τ_зф(λ) - спектральная плотность энергетической яркости источника излучения с температурой T за зеленым фильтром,
L_отн(λ,T) - нормированная спектральная плотность энергетической яркости источника излучения с температурой T,
τ_зф(λ) - спектральная характеристика пропускания зеленого фильтра.

- normalization coefficient, bringing the spectral density of energy brightness to a given level of brightness L _V ,
K (λ) = (683 lm / W) • V (λ),
V (λ) is the relative visibility of radiation in daytime vision according to the data of MCO,
R (λ, T) = L _rel (λ, T) • τ _sf (λ) is the spectral density of the energy brightness of the radiation source with temperature T behind the green filter,
L _rel (λ, T) is the normalized spectral density of the energy brightness of the radiation source with temperature T,
τ _sf (λ) is the spectral transmission characteristic of the green filter.

L_V = 3 Кд/м²,
Е = 2000 K.To carry out the calculation, we assume that
S _max = 120 mA / W,
τ _rev = 0.9,

L _V = 3 Cd / m ² ,
E = 2000 K.

For the selected NVD parameters and filter characteristics, we obtain the surface current density of the photocathode I _FC = 1.783 • 10 ^-11 A / cm ² . Comparing the obtained value I _ФК = 1.783 • 10 ^-11 A / cm ² with the threshold current for the formation of "ghosting" I _halo = 10 ^-10 A / cm ² (Development and manufacture of a technological installation for monitoring the parameters of a third-generation image intensifier tube. - Research report " Photon-2 "/ Contract N ДПВ-118-97 dated February 3, 1997 /, Moscow, Federal Research and Production Center" Geofizika-NA ") we obtain that I _FC is 56 times less than I _halo , therefore it satisfies this criterion.

P. 2 Calculation of color coordinates
In FIG. 12 is a photograph of a fragment of a helicopter dashboard illuminated in accordance with this technical proposal, and FIG. 13 is his image, observed through aerobatic night vision goggles on the second generation image intensifier tubes.

 The absence of interference and “ghosting” from the instrumentation equipment and the light signaling of aircraft, compared with the lighting of similar fragments of the instrument panel (Figs. 5 and 6), the illumination of which was carried out without taking into account the requirements of this technical proposal, showed that when developing lighting equipment for instrument lighting equipment and light alarm aircraft, it is advisable to use the main provisions of the proposed technical solution.

где

- ордината x функции сложения в системе XYZ по данным МКО 1931 г.,

- ордината y функции сложения в системе XYZ по данным МКО 1931 г.,

- ордината z функции сложения в системе XYZ по данным МКО 1931 г.We will calculate the color coordinates u 'and v', under given conditions, in the Lu'v 'system:

Where

- the ordinate x of the addition function in the XYZ system according to the data of MCO 1931,

- the ordinate y of the addition function in the XYZ system according to the data of MCO 1931,

- the ordinate z of the addition function in the XYZ system according to the data of the Moscow Scientific Settlement of 1931

 For a radiation source with a spectral brightness density shown in FIG. 10, we obtain the values u '= 0.107, v' = 0.557. As can be seen from FIG. 1 point with the calculated color coordinates u '= 0.107 and v' = 0.557 is in the range of acceptable values.

Literature
1. Mi-8 helicopter. Technical description. Book IV. Aviation equipment. - M .: "Engineering", 1972.

 2. The Mi-24D helicopter. Technical description. Book IV. Aviation equipment. - M .: "Engineering", 1983.

 3. Optoelectronic devices for scientific research. Textbook Benefit / L. A. Novitsky, A.S. Gomenyuk, V.E. Zubarev, A.M. Khorokhorov.-M.: Mechanical Engineering, 1986 .-- 432 s.

 4. Jim Malloy. Military Night Vision - 2000 and beyond. - Abstracts at the IV International Conference "Night Vision-96", London, September 3-4, 1996.

 5. Recommendations P 1.1.16-93. Requirements for green cabin lighting and light signaling of helicopters when using night vision goggles. (On 7 pages).

 6. Development and manufacture of a technological installation for monitoring the parameters of a third-generation image intensifier tube. - Report on the research work "Photon-2" (Contract N ДПВ-118-97 of February 3, 1997), Moscow, Federal Research and Production Center "Geophysics-NV".

Claims (1)

 A method of lighting instrument equipment and light signaling banners of an aircraft when observing them through night vision goggles, including generating an optical radiation stream, changing the spectral composition of the optical radiation stream, transferring the resulting optical radiation stream to the plane of the instrumentation equipment and light signaling banners of the aircraft and subsequent transfer flow into the plane of the entrance pupils of night vision goggles; optical flow amplification radiation using electronic-optical transducers for night vision goggles and transfer of the amplified optical radiation flux to the plane of the entrance pupils of the crew’s eyes, characterized in that the spectral composition of the optical radiation flux is changed into a color gamut corresponding to the color gamut of light signaling and illumination of instrumentation of the aircraft and contributing to the creation of a minimum illumination of night vision goggles, and after the transfer of the optical radiation flux to the plane the bone of the entrance pupils of the night vision goggles re-changes the spectral composition of the optical radiation flux so that the twice-changed optical radiation flux forms the photocathode current of the electron-optical transducers of the night vision goggles, not exceeding the threshold level of visual formation of “ghosting” around the images under normalized conditions the illumination of the photocathode of electron-optical converters of aerobatic night vision goggles.

Images