GB2388456A

GB2388456A - Monitoring damage to traffic bollards

Info

Publication number: GB2388456A
Application number: GB0210676A
Authority: GB
Inventors: Robin Land; John Redmond
Original assignee: Signature Ltd
Current assignee: Signature Ltd
Priority date: 2002-05-09
Filing date: 2002-05-09
Publication date: 2003-11-12
Anticipated expiration: 2022-05-09
Also published as: GB0210676D0; GB2388456B

Abstract

Monitoring damage to traffic bollards comprising a casing 10 located on a base unit 20. The base unit includes means 22 for illuminating the casing so that it is easily visible. A sensor 26 is provided for determining whether the casing is positioned properly. The sensor preferably comprises a transmitter and a receiver. The transmitter transmits a signal which is reflected by the interior of the casing 10 and received by the receiver. If the casing is not properly positioned on the base unit, then fewer reflections will be received by the receiver. If the amount of reflection drops below a predetermined level then a strobe light 24 is actuated which is visible in lieu of the casing, until the casing is replaced on the base unit.

Description

Monitoring Apparatus and Method The present invention relates to a

monitoring apparatus and method. It is particularly, but not 5 exclusively concerned with an apparatus for monitoring damage to traffic bollards, and particularly illuminated traffic bollards.

There are many thousands of traffic bollards on the UK roads. These are used for highlighting on-road 10 hazards such as sharp herbs, corners, central traffic islands or pedestrian refuges. The traditional design which is prevalent in the UK, and has been used for the past thirty years or so, comprises a reflective casing and a base unit. The base unit includes a light source 15 for illuminating the casing in low light conditions, and is normally embedded in the ground. The base unit also includes a protective polycarbonate cover, which may double as a lens for the light source. In the UK, power for the light source is usually supplied from the 20 national grid at 230V-240V.

The casings of such bollards are designed so that they are reasonably easy to knock off, and so not damage any vehicle that might collide with them However, once the casing is knocked off, the effect of the bollard is

( lost since the light from the light source dissipates, and is not reflected in the direction of approaching traffic. The on-road hazard is therefore no longer as visible to road users, and may be dangerous, particularly 5 in low light conditions.

Accordingly at its broadest, the present invention provides an apparatus for monitoring traffic bollards to determine if the casing has been removed or knocked off.

One aspect of the present invention provides an 10 apparatus for monitoring a traffic bollard having a base unit and a casing, the apparatus in use being located in association with the base unit or the casing and including: sensor means which are capable of detecting the presence or absence of the bollard casing and 15 providing an output signal; warning means for generating a warning signal; and control means for receiving the output signal and activating the warning means upon a predetermined condition.

The sensor means can take a variety of forms. For 20 example the sensor means could include a transmitter and a receiver arranged such that when the casing is in place the receiver receives a signal from the transmitter. The control means could then be arranged such that when the receiver no longer receives the transmitted signal or

does not receive it at a sufficient predetermined level, the warning means is activated.

Preferably, the transmitter and receiver may both be located on either the casing or the base unit. In this 5 case, when the bollard casing is in place, the signal from the transmitter is reflected from the interior of the casing, or from the base unit, and returns to the receiver. The control may then be arranged such that when the receiver no longer receives the signal, or does !O not receive it at a sufficient predetermined level! the warning means is activated.

Alternatively, The transmitter may be mounted on the casing and the receiver in the base unit, or vice-versa, so that there is a direct path between transmitter and 15 receiver.

Examples of transmitters and receivers that could be used for this purpose are infra-red (JR) and microwave devices. In an alternative embodiment, the sensor means may 20 include a switch, which may be positioned so as to interact with part of (such as one of the edges of) the casing, and thereby detect when the casing is removed.

In a development of this embodiment, more than one switch could be used, each being positioned so as to interact

( with a different edge of the casing, and thereby allowing detection if the casing is only knocked over, but not completely removed. Such switches may be micro-switches.

The warning means preferably includes an additional 5 light source, thereby still alerting drivers to the presence of the obstacle on which the bollard is mounted.

Preferably the warning means is highly noticeable, for example a flashing light source. Further preferably any such light source is of high intensity.

]0 The bollard casing need not be any different from that currently in use. Similarly, the base unit can be of standard construction, and in particular may include a translucent polycarbonate protective cover.

Preferably the sensor means, warning means and 15 control means are located in the base unit of the bollard. This means that they can use the same power supply as the standard illumination source for the bollard, and are also protected by any protective cover on the base unit.

20 One or both of the standard light source and the warning means may include high flux LEDs. Such LEDs consume less power compared to a conventional fluorescent or filament bulb, and generally have a longer life span,

with the attendant advantages in reduced maintenance and repair costs.

The apparatus of this aspect of the invention may be designed so that it can be retro-fitted to existing 5 bollards (e.g. by locating it in a suitable housing, thereby not incurring costs for complete replacement of the base unit.

Further aspects of the present invention provide a bollard base unit incorporating such a monitoring 10 apparatus and a bollard incorporating such a monitoring apparatus. Another aspect of the present invention provides a method of monitoring a traffic bollard having a base unit and a casing, including the steps of: detecting the 15 presence or absence of the bollard casing and providing an output signal; receiving the output signal; and generating a warning signal upon a predetermined condition of the output signal.

An embodiment of the invention will now be described 20 in relation to the accompanying drawings, in which: Figs la and lb show respectively a side view and a plan view of a traffic bollard in normal use;

( is) Figs 2a and 2b show respectively a side view and a plan view of a traffic bollard where the casing has been knocked sideways; Figs 3a and 3b show respectively a side view and a 5 plan view of a traffic bollard where the casing has been entirely knocked off; Fig 4 shows the base unit of a traffic bollard; and Fig 5 shows a schematic circuit diagram for one embodiment of the invention.

10 Figs la and lb show a traffic bollard l in its usual, upright position. The bollard comprises a base unit 20, which may be located in the ground and a casing 10 mounted over the top of the base unit 20. The casing is normally made from plastics material (either rigid or 15 flexible) and is designed so as to reflect incident light for example from vehicle headlights. The casing 10 may also have a traffic sign, such as directional arrow 12, mounted on it to convey information to road users.

Casing 10 is also illuminated from the inside by a 20 light source mounted in base unit 20. In the embodiment shown, this light source comprises twelve high flux LEDs 22, such as those supplied by Lumileds Lighting LLC, 370 west Trimble Road, San Jose, CA under the LuxconM brand.

Preferably these LEDs are arranged substantially

circularly around the centre of the base unit. The LEDs preferably have a luminous flux output of more than 10 lumen per LED, and more preferably more then 15 lumen per LED Also mounted in base unit 20 are a strobe light 24 5 and sensor means 26. The base unit is enclosed and protected by translucent polycarbonate cover 28.

In the embodiment shown, the sensor means 26 comprises an infra-red transmitter and receiver. The infra-red signal from the transmitter is reflected from 10 at least part of the internal surface of the casing 10, for example as shown by path 30, and returns to the receiver. Therefore, when the signal received by the receiver via any or all such paths is present or above a certain set threshold value, the sensor means 26 detects 15 that the casing 10 is in place.

Figs 2a, 2b, 3a and 3b show the same bollard 1 as Figs la and lb, but with the casing 10 in the process of being, and subsequently completely, knocked off base unit 20. The same reference numerals are used to label the 20 respective parts of bollard 1. It will be seen from Fig 2a that when the casing 10 is knocked sideways, not all the paths (e.g. 31) taken by the infra-red signal from the transmitter in sensor means 26 return to the receiver of sensor means 26. In fact, since the receiver picks up

many reflections of the transmitted signal via different routes inside the casing 10, when the casing JO is knocked sideways the total proportion of the transmitted signal returned is reduced. When the casing 1O has been 5 completely removed from the base unit 20, the signal from the transmitter is entirely dispersed into the air above the base unit (signal 32), and so no signal is reflected back to and detected by the receiver.

When the amount of signal detected by the receiver 10 falls below a predetermined threshold level, the warning means, e.g. strobe 24 in this embodiment, is activated.

The strobe emits a high intensity light signal (more intense than the standard illumination light provided by the light source 22). This light is clearly visible to 15 road users, even though there is no longer any casing 10 to reflect the light in the direction of the road users.

This means that although the casing 10 is no longer part of the bollard 1 (and indeed may be some distance away), the on-road hazard which the bollard 1 is marking is 20 still visible to road users. Therefore the safety of road users is not compromised by the damaged bollard.

Repair of the bollard is a simple process, simply requiring replacement of the casing 10, or of a new casing. No technical skill is required since all the

components of the illumination, sensor and warning systems are retained in the base unit 20. Replacing the casing 10 results in the signal from the transmitter of the sensor means 26 once again being reflected from the 5 interior of the casing 10, and a signal level greater than the predetermined threshold being detected by the receiver, at which point the warning means (strobe 24) ceases to operate.

Fig 4 shows the base unit 20 of bollard 1 in more 10 detail, with casing 10 removed The base uni has an exterior shell 23 which is mounted in the ground such that the majority of base unit 20 is contained below ground. The dimensions of the base unit 20 are given in millimetres. The shell supports at least one gear tray 25 on which are mounted the electrical and electronic components for the bollard. The gear tray(s) 25 can be accessed by opening hinged lid 21 once casing 10 has been removed. Lid 21 is at least partly comprised by 20 polycarbonate window 28, which allows light from the components of the base unit 20 to pass through. The components mounted on the gear tray 25 include LEDs 22 sensor- means 26.

( Fig 5 shows a possible circuit layout for the components of a bollard base unit. Power is supplied from a mains circuit, at e.g. 230V AC. This power is stepped-down to the appropriate working voltage by 5 transformer 44, and rectified to DC by rectifier 46 and capacitor 47. This circuit supplies standard lighting elements LEDs 22, and, when a switch 48 (e.g. a relay) is activated, warning strobe 24. Alternatively the power supply may be a battery.

10 A separate circuit comprises sensor means 26, which may operate at a different voltage, and thus may have require a further transformer 49. The sensor means 26 includes infra-red emitting diode 50, controlled by the transmitter controller 51 and infra-red photodiode 52 15 controlled by the receiver controller 53. When the signal received by photodiode 52 drops below a predetermined level, as assessed by controller 53, switch 48 is closed, which causes the strobe to be activated.

In one embodiment of the present invention, this 20 predetermined level is set at 50% of the flux emitted.

In an alternative embodiment, the level is set at 75% of the flux emitted. It is also possible that the level could be adjustable, for example by a screw adjustment, depending on the bollard in which the invention is to be

mounted. Higher threshold levels increase the sensitivity of the apparatus to situations where the bollard casing 10 has only been slightly knocked off, but is still damaged, and so may not be fulfilling its role.

S Higher threshold levels also decrease the sensitivity of the receiver to noise or incident radiation from other sources. It will be appreciated that other sensor means could be used to form sensor means 26, which may take a similar 1() transmitter/receiver arrangement as shown in Fig 5 (e. g. for a microwave sensor) or may simply comprise one or more microswitches, each of which may in itself be a switch that closes the circuit to cause the strobe 24 to operate, or may be linked through a relay or control IS circuit with the same effect.

It will also be appreciated that alternative warning means to strobe 24 could be used which fulfill the same function of alerting road users to the hazard in the absence of the bollard casing 10.

20 These preferred embodiments have been described by way of an example and it will be apparent to those skilled in the art that many alternatives can be made that are still within the scope of the invention.

Claims

1. Apparatus for monitoring a traffic bollard having a base unit and a casing, the apparatus in use being located in association with the base unit or the casing and including: sensor means which are capable of detecting the presence or absence of the bollard casing and providing an output signal; 10 warning means for generating a warning signal; and control means for receiving the output signal and activating the warning means upon a predetermined condition. 15

2. Apparatus according to claim l wherein the sensor means includes a transmitter and a receiver and the presence of the casing is detected by the receiver receiving a signal from the transmitter.

20

3. Apparatus according to claim 2 wherein the sensor means detects the presence of the casing by receiving a signal from the transmitter which has been reflected by the casing.

(

4. Apparatus according to claim 1 wherein the sensor means includes switch means arranged so as to detect a connection between the casing and the base unit.

5 5. Apparatus according to any one of the preceding claims wherein the warning means includes a strobe light.

6. Apparatus according to claim 5 wherein the strobe light comprises LEDs.

7. Apparatus according to any one of the preceding claims wherein the sensor means, warning means and control means are all locatable in the base unit.

15

8. A bollard base unit incorporating apparatus according to any one of the preceding claims.

9. A bollard incorporating apparatus according to any one of claims 1 to 7.

10. A method of monitoring a traffic bollard having a base unit and a easing, including the steps of: detecting the presence or absence of the bollard easing and providing an output signal; and

receiving the output signal and generating a warning signal upon a predetermined condition of the output signal. 5

11. A method according to claim 10 wherein the step of detecting includes: transmitting a detection signal from a transmitter; and if a predetermined level of the detection signal is 10 received by a receiver providing an output signal hat the casing is present, otherwise providing an output signal that the casing is not present.

12. Apparatus for monitoring a traffic bollard 15 substantially as herein described with reference to the accompanying drawings.

13. A traffic bollard base unit substantially as herein described with reference to the accompanying drawings.

14. A method of monitoring a traffic bollard substantially as herein described with reference to the accompanying drawings.