GB2196906A - Method and apparatus for locating an object - Google Patents

Abstract

The present invention relates to a method and apparatus for locating an object. One preferred application is the location of the mooring for a boat in poor visibility. In this arrangement, the invention provides a light source (32) located at the mooring (10), a control unit (34) which provides activation of the light source (32) upon receipt of a control signal, and a transmitter (14) separate from the light source eg on the boat and operably transmitting the control signal to the control unit (34). Preferably, the control signal is encoded at the transmitter (14) and is decoded at the control unit (34). <IMAGE>

Description

SPECIFICATION Method and apparatus for locating an object The present invention relates to a method and apparatus for locating an object. A particular but non-limiting application is the location of a mooring for a boat in poor visibility.

It is well known that people come to recognise the mooring for their boat by various landmarks in and around the harbour or marina. Often, such landmarks are not fixed features and may for example be other boats which are normally berthed in an adjacent location. If such landmarks are not available, because for example of a busy holiday period during which most of the boats are away from their moorings, it can become difficult to locate the correct mooring, especially in poor visibility. An obvious aid to recognition of the correct mooring might be to paint the mooring in distinctive colours. The benefit would however be lost if a number of people adopted this technique and the overall effect of many distinctively coloured moorings may well become confusing and aesthetically unattractive.

Furthermore, such distinctive markings will be of very little assistance in conditions of poor visibility.

With a view to providing an improved arrangement, the present invention provides, in a first aspect, apparatus for locating an object, comprising an emitter which operably emits a locating signal and which is located at the object, a control unit which activates the emitter upon receipt of a control signal and a transmitter separate from the emitter and operably transmitting the control signal to the control unit.

Preferably, the present invention provides apparatus for locating a mooring in poor visibility comprising a light source located at the mooring, a control unit which activates the light source upon receipt of a control signal, and a transmitter seaprate from the light source and operably transmitting the control signal to the control unit.

Beneficially the transmitter includes signal encoding means and the control unit includes signal decoding means. Thus, with appropriate setting of the encoding and decoding means it is possible for the same equipment to be installed in many different moorings in the same harbour or marina and operated without mutual interference.

Advantageously, the preferred apparatus also includes a radio transmitter located and operated together with the light source. This enables radio direction finding of the mooring prior to light from the light source becoming visible.

According to a second aspect of the present invention there is provided a method of locating an object comprising the provision of an emitter which operably emits a locating signal, locating the emitter at the object, and arranging for operation of the emitter to be controlled by a transmitter separate from the emitter.

Preferably, the present invention provides a method of locating a mooring in poor visibility comprising the provision of a light source at the mooring and arranging for activation of the light source to be controlled by a separate transmitter.

Advantageously, the transmitter is portable.

Embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which: Figure 1 is a schematic representation of a mooring buoy and transmitter incorporating the. present invention, Figure 2 is a schematic vertical section through the buoy shown in Fig. 1, and Figure 3 is a circuit block diagram useful in explaining construction and operation of the apparatus used in the embodiment shown in Figs. 1 and 2.

A preferred embodiment of the invention is illustrated in the accompanying drawings.

A floating mooring for a boat is provided by a buoy 10. In conditions of poor visibility it may be difficult to recognise the buoy and to avoid this problem the buoy is provided with a light source 12 which is activated by a transmitter 14 carried on the boat. Operation of the transmitter 14 causes operation of the light source 12 thus enabling the buoy 10 to be located.

Construction of the buoy 10 can best be assessed with reference to Fig. 2 of the accompanying drawings. The buoy comprises a main casing 16 formed of a moulded plastics material which is corrosion resistant. The interior of the casing 16 is filled with a high density foam material 18 which provides buoyancy. A central chamber 20 extends into the foam material 18 from a circular aperture 22 in the upper surface of casing 16.

Aperture 22 and central chamber 20 receive a pod 24. Casing 16 is provided with a collar 1 7 which defines aperture 22 and which carries a screw thread on its internal cylindrical surface. Pod 24 is provided with a complementary thread so that the pod can be engaged with and retained in collar 17. Anannu- lar seal 26 is provided between the upper annular surface of collar 17 and an annular lip on pod 24. With pod 24 fully threadedly engaged with casing 16, seal 26 prevents the ingress of water into casing 16.

A translucent or transparent dome 28 is provided above the annular lip of pod 24. An aerial 30 extends upwardly from the top of dome 28. A lamp 32 is housed within dome 28 and an electronic circuit 34 and power supply 36 are housed within the main body 24.

Fig. 3 is a simplified circuit board diagram useful in explaining the construction and operation of the internal components of pod 24 and the components of transmitter 14. Pod 24 houses lamp 32, electronic circuit 34 and power supply 36. Aerial 30 is supported by pod 24 and like the power supply and lamp is connected to the electronic circuit 34. Electronic circuit 34 comprises a receiver and amplifier 38, a decoder 40 and a switch and timer unit 42. Signals received by aerial 30 are amplified in circuit 38 and supplied to the decoder 40. Upon receipt of a signal matching a pre-stored code, decoder 40 passes a signal to the switch and timer unit 42. Upon receipt of such a signal, unit 42 connects the power supply 36 to lamp 32 and maintains the connection of a pre-set period of time.

As shown in Figs. 1 and 3, transmitter 14 comprises a power supply 44 (which may or may not be separate from the power supply of the boat), an operating button 46, a signal generator 48, an encoder 50 and an aerial 52.

The transmitter and receiver may be based upon any suitable form of signal transmission such as infra-red radiation, ultra-sonic signals or radio signals. Preferably, a radio signal is used and it has been found possible to implement the circuit shown in Fig. 3 using commercially available components while enabling up to 1,000,000 uniquely encoded signals to be transmitted at a single wavelength, on different transmitters, without mutual interference.

The accompanying drawings illustrate an embodiment of the invention in which the receipt of an appropriate signal activates lamp 32. In a preferred embodiment, the buoy 10 also includes a radio transmitter which is activated at the same time as lamp 32. The radio transmitter enables direction finding techniques to be used in order to locate the buoy prior to lamp 32 becoming visible from the boat.

It is believed that the benefit of the above described system can be enhanced by use of a stroboscopic light source in place of lamp 32. The periodic transmission of the stroboscopic light source is more readily detected in poor visibility conditions as constrasted with a constant light signal.

It is apparent that only a low level of maintenance will be required for buoy 10. In particular, the battery 36 will need to be replaced at an interval dependent upon use. It is to be noted that the receiver and amplifier unit 38 need only a minimal power supply, with power supply to the remaining components of the circuit being triggered by receipt of an appropriate signal. Timer unit 42 is arranged to activate lamp 32 for a predetermined period, for example 5 minutes, although the period can be re-initiated by transmission of a further signal from transmitter 14, if necessary. In addition, a solar cell arrangement can be positioned on the buoy so as to recharge the battery whenever there is sufficient incident solar radiation. A further optional addition designed to reduce unnecessary use of power is the provision of a tilt switch, such as a mercury switch.This is arranged in the main power supply and operates to isolate battery 36 when buoy 10 is tilted on its side. This may occur when the buoy is being transported from one location to another or may occur at low tide.

In the event of replacement of battery 36, or other maintenance becoming necessary, pod 24 is readily removed from casing 16.

The system should comply with local regulations concerning transmitter frequency, light colour and flash rate regulations and any other appropriate restrictions. The buoy should preferably be completely waterproof and capable of withstanding a certain level of mechanical impact, as may be caused by collosion with a boat or by dropping of the buoy into the water or onto the deck of a boat.

It is considered appropriate for the minimum range at which buoy 10 successfully receives signals from transmitter 14 to be of the order of 500 metres. With the amplifier and receiver unit 38 being powered twenty-four hours a day and an average activation time for lamp 32 of five minures per day, it is considered feasible to obtain a battery life of at least six months.

The above described embodiments are concerned with application of the present invention to the specific task of a locating a mooring for a boat in conditions of poor visibility.

The invention does however have many other applications. One such alternative application relates to the use of flashing warning lights, especially at night, at the site of road works.

Conventionally, such lights have a manual power switch and, especially for extensive roadworks, it can be particularly time consuming to switch on all the individual lamps. It is a tedious task switching on and off a large number of lamps twice each day. As a consequence lamps are often not switched on or off at the appropriate time, resulting in power wastage or danger because of non-operation.

Utilizing the above described embodiments of the invention with the casing 16 of the buoy replaced by a housing for roadwork lamp, the present invention can be used to switch a large number of roadworks lamps on and off conveniently.

Claims (16)

1. Apparatus for locating on object comprising a emitter which operably emits a locating signal and which is located at the object, a control unit which activates the emitter upon receipt of a control signal and a transmitter separate from the emitter and operably transmitting the control signal to the contorl unit.

2. Apparatus for locating a mooring in poor visibility comprising: a light source located at the mooring, a control unit which activates the light source upon receipt of a control signal, and a transmitter separate from the light source and operably transmitting the control signal to the control unit.

3. Apparatus as claimed in claim 2, wherein the light source is provided in a buoy.

4. Apparatus as claimed in any preceding claim, wherein the transmitter includes signal encoding means and the control unit includes signal decoding means.

5. Apparatus as claimed in any preceding claim, wherein the transmitter includes an ultra-sonic transducer.

6. Apparatus as claimed in any of claims 1 to 4, wherein the transmitter transmits radio waves.

7. Apparatus as claimed in any preceding claim, further comprising the provision of a radio transmitter which is activated upon receipt of the control signal.

8. Apparatus as claimed in any preceding claim, further comprising a power source for powering the emitter or light source wherein the the power source is connected to a solar cell.

9. Apparatus as claimed in claim 2, wherein the light source is in the form of a stroboscopic lamp.

10. Apparatus as claimed in claim 2, wherein the control unit comprises a timer which maintains activation of the light source for a predetermined period of time.

11. A method of locating an object comprising the provision of an emitter which operably emits a locating signal, locating the emitter at the object, providing a control unit which activates the emitter upon receipt of a control signal and providing a transmitter separate from the emitter, which transmitter operably transmits the control signal to the control unit.

12. A method of locating a mooring in poor visibility comprising the provision of a light source at the mooring and arranging for activation of the light source to be controlled by a separate transmitter.

13. A method as claimed in claim 12, further comprising the provision of a radio transmitter at the mooring so as to enable radio location of the mooring.

14. A method as claimed in claim 12 or 13 including the encoding of the signal transmitted by the signal generator.

15. Apparatus for locating an object, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

16. A method of locating an object, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.