U.S. patent application number 10/382492 was filed with the patent office on 2003-08-28 for supervision and control of airport lighting and ground movements.
This patent application is currently assigned to Safegate International AB. Invention is credited to Backstrom, Goran, Millgard, Lars, Norman, Rolf.
Application Number | 20030160707 10/382492 |
Document ID | / |
Family ID | 20373555 |
Filed Date | 2003-08-28 |
United States Patent
Application |
20030160707 |
Kind Code |
A1 |
Norman, Rolf ; et
al. |
August 28, 2003 |
Supervision and control of airport lighting and ground
movements
Abstract
A monitoring and control system controls multiple lights and
monitors their operation through two-way communication over power
lines. An interface is connected to receive control signals for at
least one of the lights from the central computer and to transmit
monitoring data concerning the lights to the central computer. The
interface communicates over the power lines with light controlling
and monitoring devices in the field to transmit the control signals
over the power lines to the light controlling and monitoring
devices and to receive the monitoring data over the power lines
from the light controlling and monitoring devices.
Inventors: |
Norman, Rolf; (Katrineholm,
SE) ; Backstrom, Goran; (Ostersund, SE) ;
Millgard, Lars; (Ostersund, SE) |
Correspondence
Address: |
BLANK ROME COMISKY & MCCAULEY, LLP
900 17TH STREET, N.W., SUITE 1000
WASHINGTON
DC
20006
US
|
Assignee: |
Safegate International AB
|
Family ID: |
20373555 |
Appl. No.: |
10/382492 |
Filed: |
March 7, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10382492 |
Mar 7, 2003 |
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08814692 |
Mar 11, 1997 |
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6573840 |
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08814692 |
Mar 11, 1997 |
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08382382 |
Feb 1, 1995 |
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08382382 |
Feb 1, 1995 |
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08007581 |
Jan 22, 1993 |
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5426429 |
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08007581 |
Jan 22, 1993 |
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07678297 |
Apr 29, 1991 |
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5243340 |
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Current U.S.
Class: |
340/953 ;
340/642 |
Current CPC
Class: |
G08G 5/065 20130101;
H05B 47/22 20200101; G08G 5/0082 20130101; H05B 47/155 20200101;
G08G 5/0026 20130101 |
Class at
Publication: |
340/953 ;
340/642 |
International
Class: |
B64F 001/18 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 7, 1988 |
SE |
8803565.4 |
Claims
We claim:
1. A monitoring and control system for monitoring and controlling
field lighting at an airfield, the monitoring and control system
comprising: a plurality of lighting means positioned at remote
locations about the surface of said airfield; a central computer
remotely located from said plurality of lighting means; power
distribution means connecting said plurality of lighting means to a
source of electrical energy; interface means connected to receive
control signals for at least one of said plurality of said lighting
means from said central computer and to transmit monitoring data
concerning said lighting means to said central computer, said
interface means being connected for controlling said plurality of
lighting means using said power distribution means for transmitting
light control signals and receiving light monitoring data from said
plurality of lighting means; and light controlling and monitoring
means connected between said power distribution means and at least
one of said plurality of lighting means for receiving said light
control signals from said interface means for operating said at
least one of said plurality of lighting means and for transmitting
light monitoring data to said interface means using said power
distribution means.
2. The monitoring and control system of claim 1, further including
motion sensors associated with said lighting means, said motion
sensors being electronically interconnected with said central
computer by means of said interface means for detection of moving
traffic on the surface of said airfield.
3. The monitoring and control system of claim 1, wherein said
lighting means are capable of operating under a plurality of
different operating parameters and wherein said operating
parameters of said lighting means are varied such that said
lighting means are at least one of lit up and extinguished in
response to said control signals.
4. The monitoring and control system of claim 1, wherein said
lighting means are capable of operating under a plurality of
different operating parameters and wherein said operating
parameters of said lighting means are varied to provide intensity
regulation.
5. The monitoring and control system of claim 1, wherein said
lighting means are capable of operating under a plurality of
different operating parameters and wherein said operating
parameters of said lighting means are switched to display stop bars
on said airfield surface.
6. The monitoring and control system of claim 1, wherein said
lighting means are capable of operating under a plurality of
different operating parameters and wherein said operating
parameters of said lighting means are switched to display center
lines on said airfield surface.
7. The monitoring and control system of claim 1, wherein said
lighting means are capable of operating under a plurality of
different operating parameters and wherein said operating
parameters of said lighting means are switched to display discrete
sectional areas on said airfield surface.
8. A method for monitoring and controlling field lighting at an
airfield, comprising the steps of: providing a plurality of
lighting means positioned at remote locations about the surface of
said airfield; providing a central computer remotely located from
said plurality of lighting means; connecting power distribution
means between said plurality of lighting means and a source of
electrical energy; connecting interface means for receiving control
signals for at least one of said plurality of said lighting means
from said central computer and transmitting monitoring data
concerning said lighting means to said central computer, said
interface means being connected for controlling said plurality of
lighting means using said power distribution means for transmitting
light control signals and receiving light monitoring data from said
plurality of lighting means; and connecting light controlling and
monitoring means between said power distribution means and at least
one of said plurality of lighting means for receiving said light
control signals from said interface means for operating said at
least one of said plurality of lighting means and for transmitting
light monitoring data to said interface means using said power
distribution means.
9. The method of claim 8, further including the step of
transmitting signals from said central computer to motion sensors
associated with said lighting means to enable selective addressing
of said motion sensors and to control the operation of said motion
sensors for detecting moving traffic on the surface of said
airfield.
10. The method of claim 8, wherein said lighting means are capable
of operating under a plurality of different operating parameters
and wherein said operating parameters of said lighting means are
varied such that said lighting means are at least one of lit up and
extinguished in response to said control signals.
11. The method of claim 8, wherein said lighting means are capable
of operating under a plurality of different operating parameters
and wherein said operating parameters of said lighting means are
varied to provide intensity regulation.
12. The method of claim 8, wherein said lighting means are capable
of operating under a plurality of different operating parameters
and wherein said operating parameters of said lighting means are
switched to display stop bars on said airfield surface.
13. The method of claim 8, wherein said lighting means are capable
of operating under a plurality of different operating parameters
and wherein said operating parameters of said lighting means are
switched to display center lines on said airfield surface.
14. The method of claim 8, wherein said lighting means are capable
of operating under a plurality of different operating parameters
and wherein said operating parameters of said lighting means are
switched to display discrete sectional areas on said airfield
surface.
15. A monitoring and control system for monitoring and controlling
lighting in an area, the monitoring and control system comprising:
a plurality of lighting means positioned at remote locations about
said area; a central computer remotely located from said plurality
of lighting means; power distribution means connecting said
plurality of lighting means to a source of electrical energy;
interface means connected to receive control signals for at least
one of said plurality of said lighting means from said central
computer and to transmit monitoring data concerning said lighting
means to said central computer, said interface means being
connected for controlling said plurality of lighting means using
said power distribution means for transmitting light control
signals and receiving light monitoring data from said plurality of
lighting means; and light controlling and monitoring means
connected between said power distribution means and at least one of
said plurality of lighting means for receiving said light control
signals from said interface means for operating said at least one
of said plurality of lighting means and for transmitting light
monitoring data to said interface means using said power
distribution means.
16. The monitoring and control system of claim 15, further
including motion sensors associated with said lighting means, said
motion sensors being electronically interconnected with said
central computer by means of said light controlling and monitoring
means for detection of moving objects in said area.
17. The monitoring and control system of claim 15, wherein said
lighting means are capable of operating under a plurality of
different operating parameters and wherein said operating
parameters of said lighting means are varied such that said
lighting means are at least one of lit up and extinguished in
response to said control signals.
18. The monitoring and control system of claim 15, wherein said
lighting means are capable of operating under a plurality of
different operating parameters and wherein said operating
parameters of said lighting means are varied to provide intensity
regulation.
19. The monitoring and control system of claim 15, wherein said
lighting means are capable of operating under a plurality of
different operating parameters and wherein said operating
parameters of said lighting means are switched to display discrete
sectional areas in said area.
20. The monitoring and control system of claim 15, wherein said
interface means is connected for controlling said plurality of
lighting means using said power distribution means for transmitting
light control signals and receiving light monitoring data from said
plurality of lighting means independently by use of a unique
address for each lighting means.
21. A method for monitoring and controlling lighting of an area,
the method comprising the steps of: providing a plurality of
lighting means positioned at remote locations about an area;
providing a central computer remotely located from said plurality
of lighting means; connecting power distribution means between said
plurality of lighting means and a source of electrical energy;
connecting interface means for receiving control signals for at
least one of said plurality of said lighting means from said
central computer and transmitting monitoring data concerning said
lighting means to said central computer, said interface means being
connected for controlling said plurality of lighting means using
said power distribution means for transmitting light control
signals and receiving light monitoring data from said plurality of
lighting means; and connecting light controlling and monitoring
means between said power distribution means and at least one of
said plurality of lighting means for receiving said light control
signals from said interface means for operating said at least one
of said plurality of lighting means and for transmitting light
monitoring data to said interface means using said power
distribution means.
22. The method of claim 21, further including the step of
transmitting signals from said central computer to motion sensors
associated with said lighting means to enable selective addressing
of said motion sensors and to control the operation of said motion
sensors for detecting moving objects in said area.
23. The method of claim 21, wherein said lighting means are capable
of operating under a plurality of different operating parameters
and wherein said operating parameters of said lighting means are
varied such that said lighting means are at least one of lit up and
extinguished in response to said control signals.
24. The method of claim 21, wherein said lighting means are capable
of operating under a plurality of different operating parameters
and wherein said operating parameters of said lighting means are
varied to provide intensity regulation.
25. The method of claim 21, wherein said lighting means are capable
of operating under a plurality of different operating parameters
and wherein said operating parameters of said lighting means are
switched to display discrete sectional areas in said area.
26. The method of claim 21, wherein said step of connecting said
interface means comprises connecting said interface means for
controlling said plurality of lighting means using said power
distribution means for transmitting light control signals and
receiving light monitoring data from said plurality of lighting
means independently by use of a unique address for each lighting
means.
Description
[0001] The present invention relates to a method and a plant for
supervising and controlling field lighting at an airport, and which
optionally include presence detectors.
[0002] The traditional implementation of a system for field lights
is as follows.
[0003] High-intensive and low-intensive lightings along approach
paths, runways and taxiways are supplied from one or more supply
points, so-called cabinets or stations situated in the airport
field, usually two for a field with one runway. These supply points
are fed with high voltage unregulated electricity which is
transformed down to 380/320 V and the supply points contain
regulator equipment, thyristor or transducer regulators or
regulating transformers for converting the unregulated electricity
into controlled, regulated electric power for supplying the light
units, which takes place via several power supply loops. Supply
takes place in two principally different ways, i.e. by series of
parallel feed to the lightings. Each lifhting is provided with a
transformer for retransforming the electricity to a suitable low
voltage for supplying the lighting with power, in addition, the
supply points also contain a supervisory system which monitors the
status of the field lighting plant, e.g. such as to ensure that a
sufficiently large number of light units function, that the
intensity of the light units is correct etc. The supply points,
i.e. the cabinets, communicate via a communication link, inter alia
with the traffic control tower supervising and operating panel,
from which the regulating and supervisory systems are controlled,
and at which information from the systems is received. This
communication takes place via separate wire pairs for each
function, or with time multiplex transmission on wires or optical
fibres.
[0004] The object of the present invention is to present a new
method for supervising and controlling field lighting, and to
provide a new field lighting plant, where each individual lighting
is addressable and includes a communicating local regulator and a
monitoring unit for supplying power to, and monitoring the
lighting. Thus each lighting or subsystem of lightings can be
controlled individually, irrespective of the sections into which
the power cabling is divided.
[0005] This object is achieved with a method according to claim 1
and a plant according to claim 9.
[0006] Furthermore, the invention enables a presence indication
system for detecting vehicle and aircraft movements on the ground
to be integrated in the field lighting system implemented in
accordance with the present invention.
[0007] Communication between the traffic control tower supervision
and operating panel takes place via a central computer to a
so-called concentrator and loop computer. The communication signals
can be in the form of time multiplexed electrical or optical
signals on signal cables or optical fibre cables.
[0008] A plurality of advantages are achieved by the present
invention compared with the already known state of the airport
lighting art.
[0009] In the implementation of a traditional field lighting
system, the different power supply loops are fed via a regulator
centrally connected to each loop for regulating the intensity of
the lightings connected to the loop. For reasons of safety, the
different lighting configurations such as approach lighting, runway
edge lighting, glidepath beacons, threshold lighting and taxiway
lighting must be fed by several loops in case there should be a
regulator or cable fault. A large number of centrally placed
regulators are therefore required for controlling the field
lighting system, and these occupy large spaces which must often be
specially built. With the present invention, on the other hand,
each lighting is provided with a local regulator which is placed at
the light fitting or in a so-called fitting well associated
therewith. At the supply point there will only be a so-called
concentrator, sling computer, contactor and modem. This results in
less voluminous equipment, which gives savings in space and cost
compared with the implementation carried out in a conventional way.
In addition, the necessary redundance is obtained automatically
with the method of implementation in accordance with the
invention.
[0010] With a conventional method of implementation there is
further required one or more lamp transformers at each lighting.
These are heavy and take up considerable space. With the present
invention, one or more of these transformers can be replaced by a
small and light electronic unit on the fitting for intensity
regulation and monitoring each individual lighting.
[0011] Since, in accordance with the present invention, each
lighting can communicate and is addressable with the aid of its
electronic unit, and is thus provided with local intelligence, a
lighting with several individual illumination points can control
these separately in spite of the supply taking place merely over a
single phase or a common cable. The necessary amount of power cable
can thus be substantially reduced.
[0012] Field lighting plant for airports in accordance with the
Invention can advantageously be made up of certain modules, namely
the lighting electronic unit (hereinafter denoted the AE unit),
loop computer, concentrator and modem, where the concentrator and
loop computer are realized with the same hardware but with
different software, the plant being completed by a central computer
and a supervising and operating unit in the traffic control tower
(hereinafter denoted TWR). This simple, modular implementation
method reduces the hardware costs for a given field lighting plant
as well as design costs for a given lighting configuration. Since
an ordinary-sized airport has several hundred lightings, the size
of the AE unit manufacturing series will be considerable, which
considerably reduces the manufacturing cost of each AE unit.
[0013] The modular method of implementation means that service and
maintenance are facilitated. If an individual lighting does not
light, this can either be due to the lamp or the corresponding AE
unit failing, or both. In the great majority of cases, it is the
lamp that fails, and therefore it is changed first. If a section
coupled to a loop computer does not light, this can only be due to
failing of the loop computer and modem, and this unit is then
changed. Service and maintenance work will thus be extremely
simplified, which is an advantage from the time, cost and personnel
expects.
[0014] With conventionally implemented field lighting systems,
there must be an ocular inspection of the field lighting at least
once a day to determine which light units are defect. For airports
with heavy traffic this must take place at night, since the runway
system is not available for inspection during daytime. This results
in increased costs. With the present invention this inspection is
eliminated, since each lighting is individually monitored and a
presentation of the status of each one can be obtained via the
sling computer, concentrator and central computer, either on a
display or printed out on a printer. In addition, monitoring can
take place without the field lighting being lit up, since the AE
unit only needs to drive a minimum amount of current through the
lamp in order to decide whether it is failing or not. This method
saves energy. Each AE unit can furthermore be implemented to enable
measuring of the operating time of the light source to which it is
connected. Since the average life (illumination time) of the lamps
in question is well known, this individual information as to lamp
status, namely illumination time and functioning/failing enables
planned maintenance of the field lighting plant, which gives better
status of the plant and more effective utilization of maintenance
personnel. The total illumination time of each light source is
suitably continuously registered at e.g. the central computer.
[0015] According to an advantageous embodiment of the plant in
accordance with the invention, each lighting includes two separate
light sources, the lighting configurations of which are identical.
Only one light source is in service at a time, but should it fail
the other light source is automatically connected, and information
is sent that there is no reserve lamp for the lighting.
[0016] Since each lighting is addressable in accordance with the
present invention, there is the possibility of guiding aircrafts,
using parts of the field lighting system, for taxiing to and from
runways, i.e., to arrange a so-called taxiway guidance system. This
can be arranged by the lighting system along the central line of a
taxiway being sectioned so that a given section is given a group
address. This section can then either have its own operating button
in a control tower panel where the section is lit when the
appropriate button is pressed, or the central computer in the
system can select a path with given input values for the taxiing
path of the aircraft, taking into consideration any maintenance
work on the taxiway, or to other aircraft movements etc. The
decided path can either be lit up simultaneously in its entirety or
successively in front of the aircraft. In existing plants this
sectioning has been achieved by each section being provided with a
separate power supply. With the present invention, the sectioning
is performed, with the aid of the AE units' addresses, in the
software, which drastically reduces the installation costs for a
guidance system, and simplifies any future changes in the section
configuration.
[0017] The invention can also be used for detecting vehicle and
aircraft movements on the ground, i.e. it can form a so-called
ground traffic detection system. In airports with heavy traffic,
the collision risk between aircraft/aircraft and aircraft/vehicle
is namely a great problem in poor visibility conditions. Since the
inventive lighting system includes "intelligent" and addressable AE
units at each point where there is a lighting, every taxiway and
runway can be divided into frequent identification blocks. This
inventive implementation of the plant, supplemented with a presence
detector allocated to each fitting the complete field lighting
system or parts thereof enables detection and supervision of
aircraft and vehicle movements along the rolling way system or
parts thereof. The signals from the ground traffic detectors are
taken up by the AE units and transmitted together with other
lighting information via loop computer and concentrator to the
central computer, which depicts the ground traffic on a display.
The central computer, or a special supervisory computer, can give
an alarm for situations where unpermitted ground traffic situations
occur. This ground traffic detection system integrated with the
field lighting system is very cost-effective compared with existing
ground radar systems. The present invention moreover permits that
only those parts of the rolling way is system selectively chosen
from the safety aspect are provided with ground traffic detection
capacity, whereby further cost savings can be made.
[0018] In accordance with a further advantageous development of the
invention, the guidance system is integrated with the ground
traffic detection system such that the centre line lights included
in the guidance system are lit up or extinguished or change
lighting colour in front of and after the taxiing aircraft,
respectively, lighting up and extinguishing the centre line lights
taking place individually or in sections with the aid of control
signals from the presence detection of the aircraft.
[0019] According to another embodiment of the plant, each lighting
position where an AE unit is to be connected is provided with an
unique address, which is automatically transferred to the AE unit
when the unit is connected, such that this address is tied to its
location and is not lost if an AE unit were to be changed.
[0020] An advantageous method of realizing an address which is not
tied to the AE unit but to its position is to arrange a plurality
of permanent magnets in the AE unit mounting such that these
magnets have a unique combination of north and south pole
orientation, giving the position in question an unique address
which is automatically transferred to the AE unit by magnetic
field-sensitive elements when the unit is connected. An eight bit
address can be realized using eight magnets, for example.
[0021] According to a still further advantageous embodiment of the
plant, and via the AE unit, the lightings are made for three-phase
supply enabling the supply to be dimensioned to cope with a phase
failure up to a predetermined current or voltage level. Up to this
level all lightings light with no change if there is a phase
failure. The central computer can be programmed such as to increase
the number of lightings which are extinguished with an increasing
modulation in order that the maximum transmitted power for two
phases is not exceeded.
[0022] Examples of the invention will now be described in more
detail, with reference to the accompanying drawings, where FIG. 1
illustrates the two systems in use today for controlling field
lighting at an airport, FIG. 2 illustrates the principle
implementation of an embodiment of the plant in accordance with the
invention, FIG. 3 illustrates the principle system implementation
of an embodiment of the plant in accordance with the invention,
FIG. 4 illustrates an embodiment of the lighting electronics in the
inventive plant, FIG. 5 illustrates an example of the realization
of a unique address for each fitting, FIG. 6 illustrates the
principle of ground traffic detection in the inventive plant, FIG.
7 illustrates an embodiment of the plant in accordance with the
invention for microwave-based ground traffic detection, FIG. 8
illustrates a system with stop lights having automatic
re-illumination for controlling ground traffic, FIG. 9 is an
idealized depiction of vehicle and aircraft ground movements and
FIG. 10 illustrates a guidance system in a conventional
construction and a system which may be realized with the plant in
accordance with the invention.
[0023] FIG. 1 illustrates the two different systems used today for
controlling the field lighting at an airport. The internationally
most usual form is the so-called series system. The power supply
line is here fed with a constant current which can be set at
different levels. The lightings 20 on the field are connected via a
so-called series transformer 50 in series with each other. Two or
more such loops are required for supplying each lighting system
such as runway edge lighting, approach lighting, glidepath beacons,
centre line lighting, taxiing lighting etc. Since the lightings 20
are in series there is most often required high secondary voltage
at the main transformer 51. The regulator 24 is connected on the
primary side. In FIG. 1 it is illustrated as a thyristor regulator
46, 48 but it can also be a transductor regulator or a regulating
transformer.
[0024] The power supply system most usual in Sweden is the
so-called parallel system. In this case the lightings 20 are
connected in parallel to each other via their individual
transformers 21 along the power supply loop. Transducer regulators
or regulator transformers are used here as well, apart from
thyristor regulators 24, 46, 48. The control and monitoring
equipment, (the equipment to the left of the dashed line in FIG.
1), is often placed in so-called cabinets or stations in the field
for these systems. For a medium-sized airport there are usually
about 10-15 such regulator units for supplying the different power
supply loops included in the field lighting system.
[0025] FIG. 2 illustrates in principle the implementation of an
embodiment of a plant in accordance with the invention. The power
supply loop is here formed of the ordinary power supply, and
connected to each lighting 20 there is a so-called lighting
electronic unit 18, denoted AE.
[0026] FIG. 3 illustrates the principle system implementation of a
plant according to an embodiment of the invention.
[0027] Field lighting installations (existing and future) are
controlled and monitored from an operating panel in the airport
control tower (TWR). In the invention, a so-called central computer
4 senses the status of the different functions of the operating
panel and sends control signals via its control program to one or
more so-called concentrators 14. These are most often placed in a
so-called power control cabinet 22 at the power supply points for
the field lighting. This communication between the central computer
4, most often placed in the apparatus room of the control tower,
and the concentrator 14 may be by a time multiplexed signal on
cable or optical fibre. Radio signalling can also be used. The
concentrator 14 sends its control signals further to one or more
loop computers 16. Via a modem communication each loop computer 16
looks after the AE units 18 which are connected to the associated
power supply loop. One loop computer can at present communicate
with a maximum of 127 AE units, with retention of the necessary
rapidity in the system. Communication between the loop computer 16
and the respective AE units 18 along the loop can either take place
with digital signals superposed on the power supply loop or via
separate signal cable. The most advantageous embodiment appears to
be communication via the power cables, no special signal cable thus
being required.
[0028] Each AE unit 18 monitors the status of the lighting fitting
20 and sends this information to the loop computer 16 in question,
for further transmission via the concentrator 14 to the central
computer 4, which coordinates the information and gives an alarm
when so required. As will be seen from FIG. 3, the status of the
plant can also be depicted on a screen 6 with associated keyboard 8
or a printer 10 in the so-called operational supervision centre. As
is further apparent from FIG. 3, this embodiment of the plant in
accordance with the invention, with supply to the lightings 20 via
AE units 18, permits this new control and monitoring method to be
mixed with the conventional technique using series of parallel
supply by the power supply loops. The loop computer 16 thus
provides a centrally placed regulator 24 with the necessary control
signals (criterion values) and it also monitors the regulator 24 so
that the right intensity is set and the right load connected to the
loop. This possibility of combining conventional power supply
methods with the new technique in accordance with the invention
makes the system very flexible.
[0029] For meeting functional reliability requirements, the central
computer 4 and the power control cabinets 22 can be doubled, as
indicated in FIG. 3 by dashed lines. When the central computer 4,
4' and the power control cabinets 22, 22' are doubled, all the
cables between the operating panel and the power control cabinets
22, 22' are similarly doubled.
[0030] A monitoring unit 12, e.g. of the so-called watchdog type,
is connected to both the central computers 4, 4' for monitoring the
function of the plant.
[0031] FIG. 4 illustrates an embodiment of the AE unit in the plant
in accordance with the invention. This comprises a modem 36 for
receiving control signals which are either carried on separate
signal cables or are digital signals superposed on the power
cabling. The AE unit further includes a lamp control unit 35 with a
microprocessor and associated interfaces 37 and power
semiconductors 39 for regulating the power supply to the light
sources 20. The microprocessor of the lamp control unit 35 also
looks after monitoring of the operation so that if incorrect light
intensity is set, or if a lamp 20 fails, the AE unit sends
information on this to the loop computer 16, c.f. FIG. 3.
[0032] Power control in the AE unit can take place according to
several different principle methods. FIG. 4 illustrates so-called
primary switching, with which, while using high switching
frequency, there is obtained extremely small lamp transformers and
thereby a very compact construction. Ideally, the transformer
decreases in size inversely proportional to the frequency. The
frequency is determined here by the construction of the lamp
control unit 35 and control can take place, e.g. by pulse length
modulation, i.e. the pulse length in the "on position" is greater
for higher output effect, and for lower output effect this pulse
length becomes shorter, the switching frequency being constant the
whole time.
[0033] A voltage regulator 41 is illustrated in FIG. 4 for
supplying the electronics. the fitting electronics also includes a
rectifier bridge 43 and a filter 45 for preventing noise from the
fittings and electronics to propagate to the network.
[0034] By each lighting having its individual regulator, at least
certain lightings can advantageously be fitted with battery backup,
so that for voltage failure the lamp in the lighting continues to
light with predetermined intensity.
[0035] Each AE unit has its unique address, as mentioned above.
There is thus obtained a possibility of individual control and
monitoring of each lighting 20 or section of lightings. FIG. 5
illustrates an advantageous method of achieving this. Permanently
situated on the lighting there is a magnetic strip 1 containing the
necessary number of permanent magnets 3. The magnets 3 are made as
reversible magnet plugs to enable pole reversing. The AE unit
contains magnetosensitive elements 2, for sensing the orientation
of the north and south poles of the magnets, this orientation
enabling a binary address code to be obtained, at 4 in FIG. 5. When
the AE unit is positioned it automatically obtains its address,
which is permanently associated with the location. This means that
each AE unit can be used anywhere in the field lighting system, as
far as addressing is concerned, which is advantageous from the
point of view of service and maintenance. The embodiment
illustrated in FIG. 5 shows how the magnetic field 5 connects the
address code from the permanently installed address code
transmitter B to an address code decoder A in the lighting
electronic unit without galvanic contacts, a signal converter and
address transmission unit 6 being connected to the decoder.
[0036] It is obviously possible to implement this memory so that
the input address is also retained when there is no current, the
input taking place with the aid of a special command to start
with.
[0037] With the technique in accordance with the invention for
controlling and monitoring the field lighting using addressable
local regulators there is obtained the field system divided into
unique addressing blocks a.sub.i, as is illustrated in FIG. 6. By
providing the field system with the required number of presence
detectors 72, c.f. FIG. 4, a system for detecting vehicle and
aircraft ground traffic can be achieved, integrated with the field
lighting system. In such a case the presence detector can be placed
on a lighting fitting, as illustrated in FIG. 7. Since each fitting
has a unique address to which the presence detector signal is
correlated, vehicle and aircraft movements on the field can be
supervised with the aid of this procedure.
[0038] In the illustrated embodiment, the presence detector 72
comprises a microwave based detector. The microwave signals are
transmitted and received via an antenna unit 71 and are evaluated
at 74. However, the detector can be based on other physical
measuring principles using such as supersonics, infrared rays, eddy
current etc.
[0039] In order to control the ground traffic, above all in
airports with heavy traffic, stop lights are required at the
entrances to runways, and also at crossings between taxiways. Such
an arrangement is illustrated in FIG. 8, the stoplights 11 are
usually sunk lightings arranged across the taxiway 80, where it is
suitable to stop the traffic. The stoplights 11 comprise a line of
at least 5 light units sunk into the taxiway and providing
directed, steady red lights solely for the traffic which is to be
stopped. Light ramps included in the stop light system must be
enabled for separate operation in the control tower, and the
installation of the stop lights should be carried out so that not
all light units in such a ramp are extinguished at the same time
for failure in the supply system.
[0040] The stop lights 11 are controlled such that when an aircraft
82 approaches an illuminated ramp of stop lights, the pilot stops
the aircraft and calls the control tower to obtain permission to
pass the stoplights. The flying controller gives a clearance sign
for passage by extinguishing the stop lights. When the aircraft 82
has passed the lights, they shall be illuminated once again with
red light as soon as possible to prevent further aircrafts from
unintentionally crossing them. This re-illumination takes place
either manually or automatically. For configurating a stop light
ramp with automatic re-illumination, and using the technique known
up to now, there are required at least two centrally placed current
regulators in order to obtain the separate operation required
according to the above, and also to obtain the necessary
redundance.
[0041] In apparatus of this kind known up to now, the automatic
re-illumination is controlled by a separate traffic signal system
which, with separate current supply and with separate control
signal cables, is connected to the regulator units for the lighting
in question. This is an expensive way of controlling and
automatically re-illuminating only five light units, for
example.
[0042] A configuration in accordance with the present invention is
illustrated in FIG. 8. Each lighting in the stop lights 11 is
provided with an electronic unit AE, which is controlled via the
power cables from the loop computer/concentrator 13, 14. Supply can
take place as illustrated in the figure, e.g. it can be three-phase
supply to obtain great redundance in the supply. The same power
supply which is used, e.g. for surrounding illuminated signs, can
be used for supplying the stop lights and thus considerably
reducing cable costs. A presence detection system is integrated
into the configuration for obtaining the automatic re-illumination.
In FIG. 8 there is illustrated a microwave-based presence detector
12 with a transmitter ND/S and a receiver ND/M. A fitting
electronics unit 17 is connected to the receiver for looking after
the signal from the receiver. The signal from the receiver is sent
on the cable 18 to the associated loop computer 13, which in turn
sends the re-illumination signal to the fitting electronic units of
the stop lights. Also schematically illustrated in the figure are
the necessary modem 15, way edge lighting 16, a power point 19 and
signal cable 21 to an operating and display panel 10 in the control
tower.
[0043] The described configuration for controlling and
automatically re-illuminating the stop lights 11 for aircraft at an
airport is substantially cheaper than the configuration according
to previously known technique, with regard to hardware cost and
cable cost. In addition there is automatically obtained great
redundance, which is important from the safety aspect, a
possibility of being able to regulate the intensity of the stop
lights being obtained as well.
[0044] The system permits vehicle and aircraft movements to be
depicted on a monitor in the control tower or at another desired
place, see FIG. 9. The described method of detecting ground traffic
is very cost effective compared with today's ground radar systems.
Such systems also have the disadvantage that in heavy rain and
snowfall they cause high background noise, thus causing
difficulties in effective supervision. Another advantage with the
solution in accordance with this invention is that if the field
movement supervision is only desired or required for a small part
of the runway system, this can be advantageously achieved.
[0045] At airports with the most heavy traffic in the world today,
so-called guidance systems have been built up to guide aircraft
when taxiing to and from runways, see FIG. 10. The lower part of
the figure illustrates how such a system is built up today. This is
done by the power supply to the lightings in question being
sectioned so that each section can be lit up and extinguished
individually. A large amount of cable is required for this, as well
as many centrally placed regulators. With the present invention
having addressable regulators the sectioning is done in the
software. Different sections of lightings can thus be connected to
the same power supply cable, and merely by defining what lighting
addresses are associated with a certain section the section in
question can be lit up and extinguished individually. This
configuration results in large cost savings, see the upper part of
FIG. 10.
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