Active standby method in an aviation obstruction lighting system

Abstract

Active standby (33) refers to the method for implementing an obstruction lighting system (2) consisting of n light sources (3), where n is a natural number and n > 1, with identical or similar specifications, placed inside i luminaires (4), where i = 1,...,n, at the top and / or along the height or width of the aviation obstacle (1) that requires marking. The method aims at safer operation, increased reliability, and an extended application field for the system (2), and is achieved through the simultaneous start of the periodic operating cycle of all n fight sources (3), main and auxiliary, in contrast to their serial operation with continuous (9) or periodic (10) light emission under prior art (9, 10, 31). The system (2) can produce either a continuous active light front with afterglow (26, 29) or without afterglow (25), or a periodic active light front, called regular flashing, with afterglow (28) or without afterglow (27), or a periodic active light front, called emergency flashing (36), with or without afterglow. It may also emit a coded message indicating position, emergency status, or communication in general, depending on the conditions and requirements defined by ICAO / FAA regulations and standards for each specific application.

Description

[0001] DESCRIPTION

[0002] Active Standby Method in an Aviation Obstruction Lighting System

[0003] The present invention relates to a method for safer operation of n light sources, where n is a natural number and n > 1, which are included in an aviation obstruction lighting system in accordance with the applicable ICAO / FAA requirements and standards, in line with the principal concept of claim 1 of the patent. Four characteristic operating modes of this method are also described, as well as an application for its further utilization.

[0004] The prior art is characterized by the separate and sequential operation of n light sources, main and auxiliary, with identical or similar specifications, which have been installed inside

[0005]

[0006] i luminaires, where i - at the top and / or along the height or width of the aviation obstruction, as indicated in Fig. 1.

[0007] Fig. 1 illustrates an obstruction ( 1) of any height that poses a hazard to aviation and therefore must be marked in accordance with the specifications defined by ICAO / FAA. At the top and / or along the height or width of the aviation obstruction, the lighting system (2) is installed, consisting of n light sources (3) inside i luminaires (4), where i =

[0008]

[0009] The control panel (5) of the lighting system is located either at the base of the obstruction or together with the luminaires.

[0010] According to the existing prior art, the obstruction lighting system is activated through the ignition of the main light source which operate continuously, or the ignition of the main light sources operating simultaneously and continuously, either with steady or flashing light emission, depending on the applicable ICAO / FAA requirements, until the end of its or their service life (6), due to material failure for any reason. Subsequently, the auxiliary light source, or auxiliary light sources, is or are activated until the end of its or their service life, and so on, up to the nth light source, as illustrated in Fig. 2.

[0011] The first sub-case of Fig. 2 (9) depicts an obstruction lighting system operating in continuous light emission mode, while the second sub-case of Fig. 2 (10) depicts a system operating in flashing mode, The vertical axis represents the system ’ s luminosity (7), and the horizontal axis represents time (8).

[0012] From the moment the first light source stops operating until the moment the nth light source ceases operation, it is necessary to replace the sources that have failed, with the ultimate purpose of ensuring that the obstruction lighting system emits light, either continuously or flashing, depending on the applicable ICAO / FAA requirements, until the end of the system ' s service life (11).

[0013] Ideally, the user of the obstruction lighting system will be notified of a light-source failure through a signal received from the electronic control circuit. This failure cannot easily be perceived by a typical observer due to the distance between the ground and the point of light emission, as well as the instantaneous switching of operation between the k and k+1 light sources, where k is a natural number less than or equal to n - 1.

[0014] The service life of a reliable light source, for example one based on LED technology, ranges between twenty thousand and at least one hundred thousand hours depending on its reduced operating point relative to its nominal rating, as well as on prevailing environmental conditions. Given the extended lifetime of LED light sources compared with other technologies, such as incandescent lamps, the existing prior art entails the risk of being unable to activate the k+1 light source after the failure of the k light source, because during the active operation of the k source, the k+ 1 source remains inactive for a long period of time. According to fundamental principles of electronic circuits operation, the conditions of outdoor environment (humidity, daily cyclic temperature fluctuations, etc.) may lead to accelerated material failure and therefore inferior performance or even total degradation of the k+1 light source when it is eventually called upon to operate. Consequently, the obstruction lighting system may potentially cease emi tting light and fail to mark the obstacle in accordance with its nominal mode of operation, placing aviation at direct risk until the failed LED light sources are replaced.

[0015] The active standby method that constitutes the subject of the present invention consists of the periodic and parallel operation among n light sources, main and auxiliary, with identical or similar specifications, which have been installed inside i luminaires, where i = 1,...,n, at the top and / or along the height or width of the aviation obstruction, as indicated in Fig. 1. Specifically, the obstruction lighting system is activated by initiating an operating cycle of all n light sources, main and auxiliary, which illuminate periodically until the end of their service life.

[0016] For further clarification of the invention, the example of Fig.4 is provided, through which all parameters of the active standby can be defined, namely the periodic operation of two (n = 2) LED light sources placed in phase with θ = 0, where θ is the angle (12) formed between the light sources relative to the observer (13), as shown in Fig. 3. To begin with, important parameters include the active-front luminous- intensity levels L..high(i) (14) and inactive-front levels Ljowfi) (15) of each source, where 0 <= L_low(i) < L_high(i) <» Ljtnax(i), for each i =■ 1,2, with L_max(i) (16) being equal to the nominal luminous-intensity level of each LED light source as specified by the respective manufacturer. As mentioned above, the service life of a light source depends on its active-front luminous-intensity level L.high(i). That is, at luminous-intensity levels lower than the nominal value, where LJhigh(i) < L_max(i), for each i = 1,2, a corresponding extension of the material’ s service life is expected, provided all other operating conditions remain unchanged.

[0017] Furthermore, it is possible for the inactive-front level of each light source to be positive, with 0 < L_low(i) < LJiighfi), since the greater the value of L_low(i) above zero, the smaller the temperature difference developed in each LED light source during level transitions. As a result, the material ’ s service life is extended, provided all other operating conditions remain unchanged.

[0018] Similarly, for the obstruction lighting system, we define the active-front luminous-intensity level L_high(S) (17) and the inactive-front level L_low(S) (18), In addition, the condition in which the obstruction lighting system exhibits one or more intermediate luminous-intensity levels (19) is referred to as afterglow. In our example, the intermediate level is equal to L_int(S) = cos θ * (L_high(2) + L_low(1)) = L_high(2) + L_low(1), with cos θ =1 since θ =0, and the relation 0 <= L_low(S) < LJnt(S) < L_high(S) holds.

[0019] Next, new important parameters introduced by the present invention include the operating period T (20) of the n light sources and of the system, the active-front time t_high(i) ≤ T of each source (21), the inactive-front time t_low(i) ≥ 0 of each source (22), with the condition t_high(i) + t_low(i) = T for each i = 1,2. Similarly, the system has an active-front time t_high(S) ≤ T (23) and an inactive-front time t_low(S) ≥ 0 (24), with t_high(S) + t_low(S) = T.

[0020] Regarding the operating modes of the system, depending on the selected parameter values, four characteristic configuration cases are distinguished: continuous emission without afterglow (25), continuous emission with afterglow (26, 29), periodic flashing without afterglow (27), and periodic flashing with afterglow (28). These are analyzed below and illustrated in Fig. 5.

[0021] In the first sub-case of Fig. 5, assume that the two light sources have a completely complementary operating cycle, meaning that t_high(l) + t_high(2) = t_high(S) = T, and both light sources have identical brightness settings. Similarly, for n light sources, we would have t_high(1) + t_high(2) +... + t_high(n) = t_high(S) = T, with all n light sources having identical brightness settings. A direct consequence for the obstruction lighting system would be continuous active-front emission without afterglow (25). This is achieved when, during one full period T, at every moment exactly one light source is at its active emission level, and all sources have identical brightness settings.

[0022] In the second sub-case of Fig. 5, assume that the light sources have a completely complementary operating cycle, meaning that t_high(1) + t_high(2) = t_high(S) = T, and the two light sources have at least one different brightness setting. Similarly, for n light sources we would have t_high(1) + t_high(2) +... + t_high(n) = t_high(S) = T, and at least one of the n light sources would have at least one different brightness setting. A direct consequence for the obstruction lighting system would be continuous active-front emission with at least one intermediate system brightness level. This operating mode is called continuous emission with afterglow (26). It is achieved when, during a full period T, exactly one light source is at the active emission front at any moment, and there is at least one difference in brightness settings between the light sources.

[0023] In the third sub-case of Fig. 5, assume that the light sources do not have a complementary' operating cycle, causing gaps in active-front emission of the system, meaning that t_high(l) + t_high(2) = t_high(S) < T, and they have equal active-front and inactive-front brightness levels, that is, identical brightness settings. Similarly, for n light sources, we would have t_hlgh(l) + t„high(2) +... - t_high(n) = t_high(S) < T, and all n light sources would have identical brightness settings. A direct consequence for the obstruction lighting system would be periodic active-front emission without any intermediate system brightness level. This operating mode is called periodic flashing without afterglow (27). It is achieved when, during a full period T, there is at least one moment during which no light source is at its active emission front, and all sources have identical brightness settings.

[0024] In the fourth sub-case of Fig. 5, assume that the light sources do not have a complementary operating cycle, causing gaps in active-front emission of the system, meaning that t_high(l) + t_high(2):::t„.high(SJ < T, and the two light sources have at least one different brightness setting. Similarly, for n light sources we would have t_high(TJ r t _high(2) +... + t_high(n) -t_high(S) < T, and at least one of the n light sources would have at least one different brightness setting. A direct consequence for the obstruction lighting system would be periodic active-front emission with at least one intermediate system brightness level. This operating mode is called periodic flashing with afterglow (28). It is achieved when, during one period T, there is at least one moment when no light source is at its active emission front, and there is at least one difference in brightness settings between the light sources.

[0025] In the fifth sub-case of Fig. S, assume that the light sources do not have a complementary operating cycle, causing overlaps in active-front emission of the system, meaning that t_high(1) + t_high(2) > t_high(S) = T. Similarly, for n light systems, we would have t_high(1) + t_high(2) +... + t_high(n) > t_high(S) = T. A direct consequence for the obstruction lighting system, regardless of any differences in brightness settings among the light sources, would be continuous active-front emission with at least one intermediate brightness level of the system. This operating mode is also called continuous emission with afterglow (29). It is achieved when, during one period T, there is at least one moment when at least two light sources are simultaneously at their active emission front.

[0026] The selection of the values of all parameters, and therefore the operating mode of the system, will be determined by the specifications of each application and defined by ICAO / FAA. Furthermore, there may be the possibility of continuously readjusting these values after the system has started operating and during its operation, ei ther manually by the user or through an automatic routine executed by the control panel, depending on the requirements at any given time.

[0027] The advantages of the invention compared with the prior art are examined in detail through Fig, 6, where we again use the example of n = 2 LED light sources placed closely, where θ = 0. For ease of understanding, the periodic-operation parameter settings for active standby are defined in the example as LJow(i) ~ 0, L_high(i) = 0.5 * L_max(i), t_high(i) = t_low(i) = T / 2, for each i = 1,2. We assume as a given ICAO / FAA specification the continuous active-front system emission without afterglow, which is also the most common case in the industry based on prior art.

[0028] First, we examine the first sub-case (30) of Fig. 6, also referred to as the ideal scenario, in which the two LED light sources complete their operating cycle according to their nominal sendee life, without any unexpected material failure occurring in between. As we observe, the prior art (31) yields the same system lifetime and the same system brightness as the case of active standby (33). In other words, the system lifetime under prior art (32) and the system lifetime under active standby (34) are equal.

[0029] Next, we examine the realistic scenario (35, 36), in which one light source, assume the first, has a shorter service life than the others, in this example, shorter than the second, due to unexpected material failure, while at least one light source, here, the second, remains functional. In this scenario, under acti ve standby, there are two possible design and operating approaches for the system when one or more light sources fail.

[0030] In the first approach, presented in the second sub-case (35) of Fig. 6, the parameters of the second light source, or, by extension, the parameters of the remaining n-1 functional light sources out of the total n, are adjusted so that the system continues to operate under conditions of continuous active-front emission. In our example this means that t'.high(2) -T, t'Jow(2) = 0 and in general: t’_high(2) + t'_high( 3) +... + t'_high(n) - T, with t'_high(1) = 0 due to its unexpected failure. The same applies for n-2 functional light sources out of n total, and so forth.

[0031] In the second approach, presented in the third sub-case (36) of Fig. 6, the parameters of the second light source, or, by extension, the parameters of the remaining n-1 functional light sources out of the total n, are not modified, and the system transitions into a periodic activefront emission mode, called emergency flashing (36). In our example this means that t'_high(2) = t_high(2) = T / 2, and ingeneral: t'_high(i) = t_high(i) for i = 2,...,n, with t‘_high(l) = 0 due to its unexpected failure. The same applies for n-2 functional light sources out of the total n, and so on.

[0032] The active standby method provides advantages over the prior art and eliminates its drawbacks, as explained below.

[0033] First, the active standby method eliminates the risk that the second light source will fail to activate due to the extended operation time of the first light source, a drawback of the prior art described earlier. Under active standby, from the initial moment the system begins operating, all n LED light sources, in this case n = 2, are used continuously, and therefore their operation is constantly checked, ensuring continuous notification regarding the proper functioning of each light source.

[0034] Second, the invention increases the response time available in the event of a system fault, due to the periodic active-front operation of the second light source under active standby, as illustrated in the third sub-case (36) of Fig. 6, as opposed to its continuous active-front operation under the prior art. With the method described in this invention, the maintenance crew is provided with significantly more time to respond to and repair the fault while the system is in the emergency-flashing state. Third, in the case of a failure of the first light source under the prior art, an ordinary observer cannot easily notice the failure, since the second light source will be activated instantaneously, as previously explained. Therefore, only the system user can be informed of the shutdown of the first light source through a notification from the automation panel. Under the third sub-case

[0036] of Fig. 6, that is, under conditions of emergency flashing, once one of the light sources stops emitting light, the system will transition to a periodic emission front, called emergency flashing, instead of the normal continuous one. Consequently, in addition to the digital notification sent to the system user by the automation panel, an extra safety layer is provided, since an ordinary observer can also detect that at least one LED light source has failed and requires replacement.

[0035] Finally, an application of the invention is presented that extends both the purpose and the static operational nature of the prior art.

[0036] Specifically, by suitably modifying the values of all active standby parameters, potentially throughout the entire operating period of the system, from start-up until the end of its service life, it becomes possible to emit coded messages, periodic or non-periodic, based on the timing relationships among the various system brightness levels.

[0037] For example, by using the operating mode of periodic flashing without afterglow or the mode of continuous emission with afterglow, the obstruction lighting system can periodically emit a predetermined number of pulses at level L_high(S) during each period T, representing disclosure of the obstacle’ s location, that is, its position, to passing aircraft.

[0038] In another example, by using the operating mode of periodic flashing with afterglow, with one or more intermediate brightness levels, the obstruction lighting system can emit an emergency coded message to passing aircraft. This message can be sent either automatically, through a control-panel routine, or manually by the user, by modifying the appropriate active standby operating parameters.

Claims

CLAIMS1. Method for implementing an obstruction lighting system (2) consisting of more than one light source (3), with identical or similar specifications, placed inside one or multiple luminaires (4), at the top and / or along the height or width of the aviation obstacle (1) that must be marked according to ICAO and FAA regulations, characterized by the simultaneous start of a periodic operating cycle of all light sources (3), main and auxiliary, referred to as active standby (33), with operating parameters including their common operating period (20); the active-front (21) and inactive-front (22) times of each source (3), whose sum is equal to the operating period (20); the system’ s active- front (23) and inactive-front (24) times, whose sum is also equal to the operating period (20); and the brightness settings, meaning the active-front (14) and inactive-front (15) luminous-intensity levels of each light source (3), the nominal luminous-intensity level specified by the manufacturer (16), the system’ s active-front (17) and inactive-front (18) luminous-intensity levels, as well as any intermediate luminous-intensity levels (19) of the system (2), until the end of their service life (6, 11), due to material failure for any reason.

2. Method for implementing an obstruction lighting system according to claim 1, characterized by the completely complementary operating mode among all light sources (3), meaning that at every moment exactly one light source (3) is at its active emission front (21),3. Method for implementing an obstruction lighting system according to claims 1 and 2, characterized by identical brightness settings (14, 15, 16) for all light sources (3), resulting in continuous active-front emission without afterglow (25) by the system (2).

4. Method for implementing an obstruction lighting system according to claims 1 and 2, characterized by at least one different brightness setting (14, 15, 16) among the light sources (3), resulting in at least one intermediate luminous-intensity level (19) of the system (2) and therefore continuous active-front emission with afterglow (26) by the system (2).

5. Method for implementing an obstruction lighting system according to claim 1, characterized by a non-complementary operating mode of the light sources (3),resulting in gaps in the active-front emission (21) of the system (2), meaning that at least one moment exists during which no light source (3) is at its active emission front (21).

6. Method for implementing an obstruction lighting system according to claims 1 and 5, characterized by the identical brightness settings (14, 15, 16) for all light sources (3), resulting in regular flashing without afterglow (27) by the system (2).

7. Method for implementing an obstruction lighting system according to claims 1 and 5, characterized by at least one different brightness setting (14, 15, 16) among the light sources (3), resulting in at least one intermediate luminous-intensity level (19) of the system (2) and therefore regular flashing with afterglow (28) by the system (2).

8. Method for implementing an obstruction lighting system according to claim 1, characterized by a non-complementary operating mode of the light sources (3), resulting in overlaps in the active-front emission (21) of the system (2), resulting in at least one intermediate luminous-intensity level (19) and thus continuous active-front emission with afterglow (29), such that at least one moment exists during which at least two light sources (3) are simultaneously at their active emission front (21).

9. Method for implementing an obstruction lighting system according to claim 1, characterized by the ability to continuously adjust all parameters (21, 22, 14, 15) of the light sources (3) at any stage of system operation (2), from start-up until the end of its service life (11), with the purpose of enabling general communication through the emission of coded messages.

10. Method for implementing an obstruction lighting system according to claims 1 and 9, characterized by the periodic emission of a coded message relating to the disclosure of the location, or position signal, of the obstacle (1).

11. Method for implementing an obstruction lighting system according to claims 1 and 9, characterized by the emergency emission of a coded message under emergency conditions.

12. Method for implementing an obstruction lighting system according to claim 1, characterized by the ability to modify, manually and / or automatically, the active-front time parameters (21) of the functional light sources (3) as a consequence of theunexpected failure of one or more non- functional light sources (3), with the purpose of preserving the operating mode (25, 26, 27, 28, 29) of the obstruction lighting system (2)., Method for implementing an obstruction lighting system (2) according to claim 1, characterized by the. absence of modification, manually and / or automatically, of the active-front time parameters (21) of the functional light sources (3) as a consequence of the unexpected failure of one or more non-fimctional light sources (3), with the purpose of triggering emergency flashing (36) and therefore providing a visual warning regarding the unexpected failure of the obstruction lighting system (2).

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