GB2470926A

GB2470926A - Lighting system with sensor controlled illumination groups

Info

Publication number: GB2470926A
Application number: GB0909947A
Authority: GB
Inventors: Robert Mckinley
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-06-10
Filing date: 2009-06-10
Publication date: 2010-12-15
Also published as: GB0909947D0

Abstract

A lighting system 10 is disclosed for a street or road. The system comprises a plurality of lamps 12 that are arranged in at least one group, with each group comprising at least two lamps. Each of the plurality of lamps comprises communication means 18 for transmitting and receiving signals to and from other lamps. At least one lamp of the group of lamps further comprises sensing means 19a for sensing the presence of a target and for outputting a signal to the communication means associated with the lamp. In use, when the sensing means of a lamp detects the presence of a target, the sensing means associated to said lamp outputs a signal to the communication means associated with said lamp, causing the communication means to transmit a signal causing lamps within the group comprising said lamp to illuminate.

Description

Lighting System The present invention relates to a lighting system and particularly, but not exclusively, to a lighting system for a road or walkway.

It is known to provide street lighting systems to illuminate streets and roads during the night and during periods of reduced visibility. Street lighting provides a safer environment for pedestrians and serves to provide drivers of vehicles and cyclists with an indication of road hazards and generally improves a drivers' road awareness.

However, street lighting is typically powered during the night and during periods of reduced lighting levels even though there may be only a few road users (vehicles, cyclists, pedestrians) passing along the road/street during these periods. In these circumstances, the power used to illuminate the street lights becomes wasted. Some local authorities have resorted to turning off street lighting during these periods in order to save electricity and thus reduce costs, however, this has lead to complaints of lack of road safety.

UK patent application number 0624646.6 discloses a system whereby a street light ahead of a road user is illuminated to provide a localised lighting for the user; the street light is subsequently switched off as the user passes the light to save electricity. A problem with this system however, is that switching a light on ahead of a user as a user progresses along a road can be distracting, particularly if the user is travelling quickly along a road, such as when in a car. In these circumstances, the lights along the road will appear to flash on and off as the user travels along the road. Moreover, the switching on and off of the lights create a nuisance for residents of nearby houses.

I have now devised a lighting system that operates on demand and which overcomes the above mentioned problems.

In accordance with a first aspect of the present invention, there is provided a lighting system, the system comprising a plurality of lamps arranged in at least one group, the group comprising at least two lamps, each of the plurality of lamps comprising communication means for transmitting and receiving signals, at least one lamp of the at least one group of lamps further comprising sensing means for sensing the presence of a target, and which is arranged to output a signal to the communication means associated with the lamp, such that, when the sensing means of the at least one lamp detects the presence of a target, the sensing means associated with said lamp outputs a signal to the communication means associated with said lamp causing said communication means to transmit a signal causing lamps within the group comprising said lamp to illuminate.

The present invention thus enables a plurality of lamps to be illuminated, for example those associated with a street, upon detecting the presence of a person for example, at one location within the street. Similarly, upon detecting the presence of a vehicle for example, at one location within the street, the lamps associated with a group of lamps are arranged to illuminate. Accordingly, controlling the periods for which the lamps remain illuminated to times when they are actually required, reduces the associated electrical energy consumption and serves to prolong the life of the lamps. In addition, activating a group of lamps at the same time, as opposed to a single lamp, overcomes the flickering effect associated with the lighting system disclosed in UK patent application number 0624646.6.

The lamps associated with the group of lamps are preferably dependant on a position of the target with respect to the lamps of the lighting system. Alternatively, or in addition thereto, the lamps associated with the group of lamps are preferably dependant upon a movement of the target.

Preferably, the lamps associated with the group of lamps are dependent on a speed of the target.

Preferably, at least one lamp of said group of lamps comprises a communications hub for communicating with a control centre for the lighting system.

Preferably, one or more of the lamps are associated with at least two groups.

Preferably, the sensing means comprises configuration means for dividing a sensing region into at least two sensing zones. Preferably, the at least two sensing zones separately comprise a pavement or walkway, and a road or similar, for example.

The sensing means preferably comprises a focussing arrangement for sensing the presence of a target over an angular range.

The sensing means preferably comprises means for determining a temperature profile of the target from a wavelength distribution that is generated from the target.

The sensing means preferably further comprises means for comparing the temperature profile to characteristic profiles of a plurality of targets, such that the sensing means can discriminate between a vehicle target and a pedestrian target.

Preferably, the wavelength distribution comprises an infra-red wavelength distribution of the target.

The sensing means associated with the at least one lamp preferably comprises an infra-red sensing array. Alternatively, or in addition thereto, the sensing means preferably comprises a passive infra-red sensing array.

The sensing means is preferably arranged to illuminate the respective lamp and the group of lamps associated with said lamp to a first level of luminosity, upon detecting the presence of a vehicle, so as to indicate the layout of the road ahead of the vehicle.

The sensing means is preferably further arranged to illuminate the respective lamp and the group of lamps associated with said lamp, to a second level of luminosity, upon detecting the presence of a pedestrian upon a pavement or walkway or similar, to illuminate the walkway. Preferably, the first level of luminosity is less than the second level of luminosity.

Preferably, each lamp of the lighting system further comprises ambient light sensing means for sensing the levels of ambient light.

The first and second levels of luminosity are preferably dependent upon the ambient light levels.

Preferably, the lighting system comprises a street lighting system.

The lamps associated with the lighting system are preferably separately mounted to a lamp post or similar.

In accordance with a second aspect of the present invention as seen from a second aspect, there is provided a method of powering lamps of a lighting system, the method comprising the steps of: -comparing the levels of ambient light with respect to a threshold value; -sensing for the presence of a target; -communicating the sensed presence to at least two lamps; and -powering said at least two lamps in dependence of the sensed presence of a target and the levels of ambient light with respect to the threshold value.

Preferably, the at least two lamps are powered when the levels of ambient light are below a threshold level and a target is sensed.

In accordance with a third embodiment of the present invention, there is provided a sensor for sensing the presence of a target in controlling a lighting system, the sensor comprising radiation capturing means that is arranged to capture radiation from a target within a sensing region, configuration means for configuring the sensing region into at least two sensing zones and means for determining a location of the target within the sensing region.

The sensor preferably comprises means for determining a temperature profile of the target from a wavelength distribution of the radiation that is generated from the target.

The sensor preferably further comprises means for comparing the temperature profile to characteristic profiles of a plurality of targets, such that the sensor can discriminate between a vehicle target and a pedestrian target.

Preferably, the wavelength distribution comprises an infra-red wavelength distribution of the radiation that is generated from the target.

Preferably, the radiation capturing means comprises an infra-red sensing array. The sensing array preferably comprises a plurality of sensing elements that are sensitive to radiation from a particular direction. The configuration means preferably configures a first set of sensing elements to correspond with a first sensing zone within the sensing region and a second set of sensing elements to correspond with a second sensing zone within the sensing region.

The radiation capturing means preferably further comprises a focussing arrangement for capturing radiation from an angular range.

The sensor preferably comprises communicating means for communicating a sensed target to a further sensor.

An embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which: Figure 1 is schematic illustration of the lighting system according to an embodiment of the present invention; Figure 2 is a schematic illustration of one of the plurality of lamps illustrated in figure 1, as viewed from the front; Figure 3 is a schematic illustration of the components of one of the plurality of lamps associated with the lighting system of figure 1; and, Figure 4 is a schematic illustration of the sensing region of the lamp of figure 2.

Referring to the drawings, there is illustrated a lighting system 10 according to an embodiment of the present invention. In the embodiment illustrated in figures 1 and 2 of the drawings, each lamppost 11 comprises a substantially upright member ha and a support member hib which extends substantially transverse to the upright member ha. A lamp 12 is disposed on the underside of support member hib at a distal end thereof and is used to illuminate a section of road 13 and roadside 14 for road users (not shown), such as drivers of vehicles, cyclists and pedestrians, thereby enabling road users to pass safely along the road 13 and roadside 14.

The lamps 12 of the lighting system 10 are arranged in a parallel configuration and in groups, with each group comprising at least two lamps 12. At least one lamp 12 within each group comprises a communications hub 15 for communicating with a control centre 16 which monitors the operation of the groups of lamps 12 within the system 10.

The communications hub 15 is arranged to transmit operating characteristics of the lamps 12 within a particular group to the control centre 16 and further receive signals, such as for example, a software up-date for the lamps of the group from the control centre 16.

Referring to figure 3 of the drawings, the operation of a lamp is controlled by a processing unit 17 that is arranged to process signals received as input from a communications unit 18, a target sensor 19, an ambient light sensor 20 and a diagnostics sensor 21. The processor 17 outputs a processed signal which is received as input by a lamp hardware controller 22. The lamp hardware controller 22 subsequently controls the physical operation of the lamp 12, such as the on-off state and luminosity control, for example.

The communications unit 18 is disposed atop the support member 11 b of the lamppost 11 and is arranged to transmit and receive signals to and from other lamps 12 within a particular group of lamps 12. The communications unit 18 is further arranged to communicate signals to and receive signals from the communications hub 15 associated with that particular group, for subsequent transmission and reception to and from, respectively, the control centre 16.

In the embodiment illustrated in figure 1 of the drawings, each lamp post 11 comprises a target sensor 19. However, it is also envisaged that a lighting system comprising target sensors 19 disposed on alternate lamp posts 11, or every third lamp post 11 for example, could also be employed. The target sensor 19 comprises a pair of sensors 19a, 19b such as a pair of infra-red sensing arrays or passive infra-red sensing arrays that are disposed at substantially opposite sides of the upright member ha of the lamppost 11. The target sensors 19 are arranged to detect the presence of a target, such as a pedestrian or vehicle (not shown) or similar that may be moving along the road 13 or which may otherwise be stationary within the road 13 or at roadside 14, for example on a pavement. Each sensor 19a, 19b comprises an array of sensing elements (not shown), for example bolometers (not shown), with each element being sensitive to infra-red radiation from a particular direction. Accordingly, the position of the target is determined by analysing which element or elements of the array sense the target. The sensors 19a, 19b further comprise a focussing arrangement 23 or lens which capture infra-red radiation from targets over a wide angular range and which further facilitate the tracking of targets, namely the speed and direction, within the sensing range 24.

The use of a pair of sensors 1 9a, 19b, one either side of the upright member 11 a -as opposed to a single sensor -eliminates regions of the sensing range 24 that would otherwise be obscured from the target sensors 19a, 19b by the upright member ha, such that the pair of sensors 1 9a, 1 9b can sense the complete environment around the lamppost 11. Moreover, the sensing range 24 of each target sensor 19a, 19b is arranged to overlap each other, as illustrated in figures 2 and 4 of the drawings, and further overlap with the sensing range of target sensors 19a, 19b disposed on other lampposts 11, to improve the detection of targets, such as pedestrians and/or vehicles (not shown).

The targets sensors 19a, 19b are configured using a configuration unit 25 to differentiate between various regions within the sensing range 24. This is achieved by dividing the array elements (not shown) of each target sensor 19a, 19b into regions which correspond with signals received from various locations, such as the pavement 14 and the road 13, for example. This division of the sensing range 24 provides the target sensors 19a, 19b with a level of intelligence, such that the sensors 19a, 19b can differentiate between pedestrians and vehicles (not shown), for example.

To further enhance the differentiation of vehicles, cyclists and pedestrians, for example, the target sensors 19a, 19b further comprise a spectral analyser for determining the temperature profile of the target from the infra-red wavelength distribution that is generated from the target. The sensors 19a, 19b subsequently compare the determined temperature profiles with pre-stored characteristic temperature profiles of vehicles, cyclists and pedestrians (not shown), to determine the type of target being sensed.

The ambient lighting sensor 20 is arranged to detect levels of ambient light and outputs a signal to the processing unit 17 in dependence of the ambient lighting levels. The ambient light sensor 20 is further used to control the luminosity level of the respective lamp 12 in dependence of the ambient lighting levels and thus avoid unnecessary use of electrical energy.

The diagnostics sensor 21 is arranged to monitor the operating characteristics of the lamp 12, such as current, voltage etc and outputs these characteristics to the processing unit 17. If a lamp 12 fails or if a fault develops, then the diagnostics sensor 21 is arranged to isolate the lamp 12 from the lighting system 10 and further communicate the failure or fault to the communication unit 18 via the processing unit 17, for onward communication to the control centre 16 via the communications hub 15.

In this manner, the control centre 16 becomes aware of the lamp 12 fault or failure and can arrange for an engineer to service the lamp 12.

The operation of the lamps 12 is dependent on the signals received from each of the sensors 19, 20, 21. Accordingly, for a lamp 12 to illuminate the diagnostics sensor 21 must indicate that there are no faults associated with the lamp 12, the ambient lighting levels must be below a threshold level of luminosity and the target sensor 19 of one lamp 12 of a group of lamps must detect the presence of a target (not shown). If any of these conditions are not met, then the respective lamp 12 will not illuminate.

Upon detecting the presence of a target (not shown) on a pavement 14 for example, the target sensor 19 will recognise the target as a pedestrian (not shown) and output a signal to the processing unit 17, thereby instructing the processing unit 17 to illuminate the lamp 12 via the hardware controller 22. Assuming the ambient light levels are below the threshold level and the lamp 12 is functioning properly, then the lamp 12 will illuminate. At the same time, the processing unit 17 will instruct the communications unit 18 to transmit a signal to the other lamps 12 within the same group causing each of these lamps 12 to illuminate also. In this manner, all the lamps 12 associated with a street for example, will illuminate.

As the pedestrian (not shown) moves along the pavement 14, the target sensors 19a, 19b of other lamps 12 will also detect the pedestrian (not shown) and similarly communicate this detection to other lamps 12 within the group so that all lamps 12 within the group remain illuminated. The successive detection of the pedestrian (not shown) by the sensors 19a, 19b of each lamp 12 provide an indication of the direction of the travel of the pedestrian (not shown) along the pavement 14 and thus the group of lamps 12.

The lamps 12 associated with a particular group of lamps are dependent upon the position of the target (not shown), in this case the pedestrian, with respect to the lamps 12 of the system 10. According to a first embodiment of the present invention, as the pedestrian (not shown) nears the end of a particular group of lamps 12, a further lamp 12 or number of lamps 12 become associated with the group and thus illuminate, and a similar number of lamps 12 at the opposite end of the group are switched off.

Accordingly, a number of lamps 12 remain illuminated in front of and behind the pedestrian (not shown).

According to a second embodiment of the present invention, the lamps 12 disposed adjacent a neighbouring group of lamps 12 are also arranged to communicate the presence of a pedestrian (not shown), for example, to the adjacent group of lamps 12, causing the adjacent group of lamps 12 to illuminate. Accordingly, successive groups of lamps 12 become illuminated as the pedestrian (not shown) travels along a street or road, for example. As the pedestrian (not shown) moves out from the sensing range 24 of a particular group of lamps 12 however, the group of lamps 12 will switch off.

Upon detecting the presence of a vehicle (not shown), then due to the increased speed of travel along the road 13, compared to that of a pedestrian (not shown), a larger number of lamps 12 are arranged to illuminate, so as to illuminate a greater distance along the road 13. In this manner, the number of lamps 12 associated with a particular group of lamps 12 is dependent on the sensed target. In addition, the sensed vehicle (not shown) as opposed to a pedestrian (not shown), is communicated to the processing unit 17 which causes the lamp 12 to illuminate to a lower level of luminosity compared with that associated with the detection of a pedestrian (not shown), since the vehicle (not shown) will have headlights to illuminate the road 13 ahead. The illumination of the lamps 12 however serves to provide the driver of the vehicle (not shown) with an indication of the layout of the road 13 ahead, for example a sharp bend, and thus preserve the driver's road awareness.

If one of the lamps 12 fails or develops a fault, then the diagnostics sensor 21 will isolate the lamp 12. However, the parallel configuration of the lamps 12 ensures that even in the event of a failure of one or more lamps 12, others lamps 12 can still receive power for normal operation.

The lamps 12 associated with the lighting system 10 further comprise a clock 26 for monitoring the lunar month cycle. During periods of full moon, it is known that the levels of ambient light can be increased, particularly if there is little cloud cover. The clock 26 is thus used in conjunction with the ambient light sensor 20, as a check for the levels of ambient light. When illuminated therefore, the luminosity level of the lamps 12 will depend on the levels of ambient light and thus possibly the lunar month cycle. On a particularly dark night for example, the lamps 12 may be illuminated to a greater extent compared with a clear night during full moon, in which there is a greater level of ambient light.

From the foregoing therefore, it is evident that the lighting system of the present invention preserves the benefits of street lighting while reducing the energy wastage associated with maintaining the operation of the lamps throughout the night and during periods of reduced visibility.

Claims

Claims 1. A lighting system, the system comprising a plurality of lamps arranged in at least one group, the group comprising at least two lamps, each of the plurality of lamps comprising communication means for transmitting and receiving signals, at least one lamp of the at least one group of lamps further comprising sensing means for sensing the presence of a target, and which is arranged to output a signal to the communication means associated with the lamp, such that, when the sensing means of the at least one lamp detects the presence of a target, the sensing means associated with said lamp outputs a signal to the communication means associated with said lamp causing said communication means to transmit a signal causing lamps within the group comprising said lamp to illuminate.
2. A system according to claim 1, wherein the lamps associated with the group of lamps are dependant on a position of the target with respect to the lamps of the lighting system.
3. A system according to claim 1 or 2, wherein the lamps associated with the group of lamps are dependant upon a movement of the target.
4. A system according to any preceding claim, wherein the lamps associated with the group of lamps is dependent on a speed of the target.
5. A system according to any preceding claim, wherein one or more of the plurality of lamps are associated with at least two groups.
6. A system according to any preceding claim, wherein at least one lamp of said group of lamps comprises a communications hub for communicating with a control centre for the lighting system.
7. A system according to any preceding claim, wherein the sensing means comprises a focussing arrangement for sensing the presence of a target over an angular range.
8. A system according to any preceding claim, wherein the sensing means comprises means for determining a temperature profile of the target from a wavelength distribution that is generated from the target.
9. A system according to claim 8, wherein the sensing means further comprises means for comparing the temperature profile to characteristic profiles of a plurality of targets, such that the sensing means can discriminate between a vehicle target and a pedestrian target.
10. A system according to claim 8 or 9, wherein the wavelength distribution comprises an infra-red wavelength distribution of the target.
11. A system according to any preceding claim, wherein the sensing means comprises configuration means for dividing the sensed angular range into at least two sensing zones.
12. A system according to claim 11, wherein the at least two sensing zones separately comprise a pavement or walkway, and a road or similar.
13. A system according to any preceding claim, wherein the sensing means associated with each lamp comprises an infra-red sensing array.
14. A system according to any preceding claim, wherein the sensing means comprises a passive infra-red sensing array.
15. A system according to any preceding claim, wherein the sensing means is arranged to illuminate the respective lamp and the group of lamps associated with said lamp to a first level of luminosity, upon detecting the presence of a vehicle.
16. A system according to any preceding claim, wherein the sensing means is arranged to illuminate the respective lamp and the group of lamps associated with said lamp, to a second level of luminosity, upon detecting the presence of a pedestrian.
17. A system according to claim 15 and 16, wherein the first level of luminosity is less than the second level of luminosity.
18. A system according to any preceding claim, wherein each lamp of the lighting system further comprises ambient light sensing means for sensing the levels of ambient light.
19. A system according to claim 18 as appended to claim 17, wherein the first and second levels of luminosity are dependent upon the ambient light levels.
20. A system according to any preceding claim, wherein the lighting system comprises a street lighting system.
21. A method of powering lamps of a lighting system, the method comprising the steps of: -comparing the levels of ambient light with respect to a threshold value; -sensing for the presence of a target; -communicating the sensed presence to at least two lamps; and -powering said at least two lamps in dependence of the sensed presence of a target and the levels of ambient light with respect to the threshold value.
22. A method according to claim 21, wherein the at least two lamps are powered when the levels of ambient light are below a threshold level and a target is sensed.
23. A sensor for sensing the presence of a target in controlling a lighting system, the sensor comprising radiation capturing means that is arranged to capture radiation from a target within a sensing region, configuration means for configuring the sensing region into at least two sensing zones and means for determining a location of the target within the sensing region.
24. A sensor according to claim 23, further comprising means for determining a temperature profile of the target from a wavelength distribution of the radiation that is generated from the target.
25. A sensor according to claim 24, further comprising means for comparing the temperature profile to characteristic profiles of a plurality of targets, such that the sensor can discriminate between a vehicle target and a pedestrian target.
26. A sensor according to claim 24 or 25, wherein the wavelength distribution comprises an infra-red wavelength distribution of the radiation that is generated from the target.
27. A sensor according to any of claims 23 to 26, wherein the radiation capturing means comprises an infra-red sensing array.
28. A sensor according to claim 27, wherein the sensing array comprises a plurality of sensing elements which are sensitive to radiation from a particular direction.
29. A sensor according to claim 28, wherein the configuration means configures a first set of sensing elements to correspond with a first sensing zone within the sensing region and a second set of sensing elements to correspond with a second sensing zone within the sensing region.
30. A sensor according to any of claims 23 to 29, wherein the radiation capturing means further comprises a focussing arrangement for capturing radiation from an angular range.
31. A sensor according to any of claims 23 to 29, further comprising communicating means for communicating a sensed target to a further sensor.