GB2414586A

GB2414586A - Swimming pool alarm

Info

Publication number: GB2414586A
Application number: GB0510647A
Authority: GB
Inventors: Robin Christopher Hatherell
Original assignee: OSL GROUP HOLDINGS Ltd
Current assignee: OSL GROUP HOLDINGS Ltd
Priority date: 2004-05-25
Filing date: 2005-05-25
Publication date: 2005-11-30
Also published as: GB0510647D0; GB0411645D0

Abstract

A safety device comprises a first sensor 1 in communication with a body of liquid, such as a swimming pool, and a second sensor 2 in communication with the air above the body of liquid. An alarm is sounded only if both sensors detect the presence of a foreign object. The first sensor may detect surface motions or vibrations or subsurface pressure differences and the second sensor may detect sound. The alarm may be suppressed if the signals detected by the two sensors are dissimilar. A control means may also compare detected signals with stored signals known to be characteristic of false alarms. An override mechanism is provided to allow the pool to be used without setting off the alarm, the override being capable of automatically reactivating the alarm after a period of inactivity. The safety device may be contained in a single vandal resistant casing and may be solar powered.

Description

POOL ALARM

Field of the Invention

The present invention relates in general to a safety device for detecting the introduction and/or presence of a foreign body within a body of water such as a swimming pool.

Background of the Invention

There are many circumstances in which it may be desirable or necessary to provide a safety device for a body of liquid, such as a pond or a swimming pool for example, to detect and indicate that a foreign body has been introduced into, or is otherwise present, in the water. In particular, it may be highly desirable to provide a safety device for a body of water such as a swimming pool or pond which can detect and indicate quickly and reliably that a small child or animal may have fallen into it. .

Swimming pool alarms are available which detect, for example, vibrations within the body of liquid and activate an alarm or the like in the event that such vibrations are detected. However, such devices are often unreliable because they can easily be triggered to enter the alarm state by vibrations caused by, for example, wind or surface turbulence caused by other external factors which are not related to a person or animal falling into the : swimming pool.

Numerous alarm designs have been developed it an attempt overcome the above mentioned problem by providing alarm systems that detect and compare more than one input reading before triggering an alarm. One such example of an improved pool alarm device is provide in UK Patent No GB2376553B. The safety device disclosed in the granted UK Patent has two separate sensors that collect different forms of input from the water(e.g.

surface vibrations or changes in water pressure), which are then compared to determine whether a body has fallen into the water or in fact the water is simply being caused to move by the wind, for example. Further examples of alarm systems known in the art are referenced in the above mentioned patent.

However, despite the provision of multiple sensors false alarms are still generated by these pool alarms. Thus there is still a need for the development of alarms with yet further improved reliability.

Summary of the Invention

In light of the above mentioned need for more reliable pool alarms, the present invention provides a safety device according to claim 1. By providing a liquid based sensor and an air based sensor the device can formulate a more accurate analysis of whether a human or an animal has fallen into the body of liquid. In this regard it will be appreciated that, the water based sensor will detect water movement in the form of pressure waves, whilst the air based sensor collect information from the air surrounding liquid, such as noises (also in the form of pressure waves), and thereby determine whether the liquid movement is likely to be being caused by a human or an animal that has fallen into the liquid.

In one embodiment of the present invention the first and second parameter data collected by the device will be compared with one another.

This embodiment of the safety device works by comparing the first parameter :.: . data, for example the pressure waves created in a body of liquid when an object falls in, with the second parameter data, for example the noise created when the object hits the water. By comparing the data detected from the air and the water, for example the duration and amplitude of the pressure waves, ..

the device will be able to determine whether an object has fallen into the body : of liquid. .

By way of further example in the case of a swimming pool, if the liquid based sensor detects pressure waves caused by wind then there will be no accompanying noise, and thus no pressure waves, to be detected by the air based sensor, which means that the alarm will not be raised.

However, if the water based sensor detects pressure waves caused by a child falling into the water then there is extremely likely to be at very least the sound of a splash when the child hits the water, resulting in creation of pressure waves of a similar form to those in the water, and thus the alarm will be raised.

In an alternative embodiment of the present invention, the safety device may also comprise a data recognition means that is programmed with at least one data pattern, and whereby the provision of false indications by the device is prevented by the comparison of data detected by the device with the at least one data pattern to qualify whether the detected data is indicative of the possible introduction and/or presence of a foreign body or object in or on the body of liquid.

Further preferably the at least one data pattern, programmed into the data recognition means may be such that a collection of data indicative of false alarms are available to be compared with data detected by the device. In a situation where the data is sound energy, typical examples of sound associated with false alarms may include wind, rain, car noise, footsteps, animal noise and other forms of noise pollution. It will be appreciated that the above list of programmed acoustic patterns is not exhaustive.

Alternatively, the at least one data pattern programmed into the data recognition means may be such that a collection of data indicative of the introduction and/or presence of a foreign body or object in or on the body of liquid are available to be compared with data detected by the device. Once again in a situation where the data being detected is sound energy, typical :.: . examples of indicative data include loud splashes, irregular splashing sounds, ë and human shouting. Again, it should be appreciated that the above list is not to be considered exhaustive.

When data patterns used are acoustic in nature the data patterns may comprise signals having particular amplitudes and duration times that correspond to the known patterns of the above mentioned noise types.

Whilst the preferred form of second parameter detected by the device of the present invention is sound, the form of the first parameter, as detected by the liquid-communicating sensor, can take a variety of forms.

With regard to both embodiments of the present invention, one preferred form of the first parameter may be surface motion or vibration of the liquid. An alternative form of the first parameter may be the changes in the underwater pressure of the body of liquid. Thus the first form relates to movement on the surface of the liquid whilst the second relates to movement below the surface.

It is also appreciated that a data recognition means may also analyse the parameters detected by the first liquid-communicating detection means, thus providing similar benefits to those discussed in connection with the second detection means.

Whilst the above forms are disclosed as alternatives, it is appreciated that the use of a liquid-communicating sensor that can detect both forms may provide a further improvement to the accuracy of the safety device.

For safety reasons the default setting of the safety device is on, in this way there can never be a situation where the user forgets to activate the device.

However in the case of a swimming pool, it would be impractical if the device was constantly on. In view of this problem the safety device may further comprise an override mechanism that disables the safety device to enable the body of liquid to be used without setting off the device, said override mechanism comprising a time out means that reactivates the device after a set period of time. It will be appreciated that the override mechanism can be used manually to both activate and deactivate the safety device.

Advantageously, the time out means will be arranged to reactivate the :.: . override mechanism after a set period of time during which no sound is detected by the device. In this way the safety device can be turned off whilst someone is using the body of liquid, e.g. swimming, and then after the swimmer finishes and leaves the pool, thus returning silence to air surrounding the body of liquid, the safety device will eventually reactivate : itself.

Preferably, the safety device may have its own self contained power source. In the case of swimming pools, and other external bodies of water, it may be advantageous for the safety device to derive power from solar cells.

Once the safety device detects the possible introduction and/or presence of a foreign body or object in or on the body of liquid the indication means need to raise the alarm so that assistance can be called. Preferably the indicating means may comprise at least one signalling means selected from the group containing: audible signal, visible signal and radio signal.

Typical examples of suitable signals include a siren, flashing lights, and a radio transmission to a siren or flashing light located in a more populated area(such as the house to which the swimming pool is connected).

In the case of safety devices that are situated outside, it may be advantageous for the entire device to be housed within a durable, possible vandal proof, container.

Whilst the preferred application for the safety device of the present invention is for swimming pools, it is appreciated that the device could be usefully applied to a variety of liquid bodies, such as large liquid container tanks and ponds.

Brief Description of the Drawings

In the drawings, which illustrate an exemplary embodiment of the invention: Figure 1 shows the operating process of the sensing system; Figure 2 show the periphery requirements of the sensing system that allow it to declare that an object has entered the body of liquid; and Figure 3 shows a schematic of the safety device of the present invention in situ next to a body of liquid.

. Detailed Description of the Preferred Embodiment As shown in Figure 1, the sensing system of the present invention comprises one or more air sensors 1 and one or more water sensors 2 whose outputs are conducted to a microprocessor that contains an algorithm 3. The .

sensors 1, 2 may consist of specially housed piezoelectric material, : microphones, hydrophores or another arrangement sensitive to changes in : energy levels.

The algorithm 3 analyses the output of the sensor over a period of time and determines whether the change in energy levels originates from the air, the water, or both. Such analysis leads to a decision 4 that concludes the sensing process and commences the warning process as outlined in figure 2.

The embodiment of the sensing system illustrated in figure 2 shows the actions that follow a particular decision 4. If the algorithm 3 determines that the change in energy level originates from the air 5 alone then the sensing system will continue its normal sensing activities 7. If the decision 4 determines that the change in the energy levels originates the water 6 alone then the sensing system will continue its normal sensing activities 7. However, if the decision 4 determines that the change in energy levels originate from both the air 5 and the water 6 then this provides a stimulus that activates the warning systems represented in this embodiment by a piezo sounder 9, a strobe light 10, and the commencement of wireless transmission 11. The wireless transmission 11 may send a coded signal to a remote sounder 12, which may be positioned anywhere within signal range.

In an alternative embodiment of the present invention, which comprises a pre-programmed sound recognition means, it will be appreciated that an additional process stage will be provided to the system of figure 2. The additional process stage comprising of the action of cross referencing the detected energy levels with known energy levels to determine the nature of such energy levels, i.e. whether they relate to a likely false alarm.

A sensing system as illustrated in figures 1 and 2 is embodied in the form of the safety device shown in figure 3. With the electronic circuitry, air sensors 2, sounder 9, strobe light 10 and wireless transmitter 11 enclosed within the waterproof plastic enclosure 15, which has a waterproof conduit 13 providing an electrical connection with water sensors 1 communicating with :.: . the body of liquid. The waterproof enclosure 15 is fixed to the container of the body of liquid, which may be a swimming pool surround 14. The waterproof enclosure 15 is partially acoustically isolated from the pool surround 14 by means of physical isolation and the use of energy absorbent materials, such ë as foam.

- .e : ë

Claims

1. A safety device for detecting the introduction and/or presence of a foreign body or object in or on a body of liquids the safety device comprising: a first liquid-communicating detection means for detecting a first parameter from the liquid, said first parameter being indicative of the possible introduction and/or presence of a foreign body or object in or on the body of liquid; a second air-communicating detection means for detecting a second parameter from the air located around the liquid, said second parameter being indicative of the possible introduction and/or presence of a foreign body or object in or on the body of liquid; and an indicating means, which indicates the introduction and/or presence of a foreign body or object in or on the body of liquid only in the event at least both said first and second parameters are detected by said first and second ë detection means respectively. ë .

: ..

2. The safety device of claim 1, further comprising a processing means : that compares the characteristics of the first and second parameter data, and wherein said processing means is adapted to prevent the activation of the indicating means if the characteristics of the first and second parameter data .

are not similar in nature.

3. The safety device of claim 1, wherein the second parameter is sound.

4. The safety device of claim 1, 2 or 3, wherein the device further comprises a data recognition means that is programmed with at least one data pattern, and whereby the provision of false indications by the device is prevented by the comparison of data detected by the device with the at least one data pattern to qualify whether the detected data is indicative of the possible introduction and/or presence of a foreign body or object in or on the body of liquid.

5. The safety device of claim 4, wherein the at least one data pattern programmed into the data recognition means is such that a collection of data indicative of false alarms are available to be compared with data detected by the device.

6. The safety device of claim 4, wherein the at least one data pattern programmed into the data recognition means is such that a collection of data indicative of the introduction and/or presence of a foreign body or object in or on the body of liquid are available to be compared with data detected by the device.

7. The safety device of any of the preceding claims, wherein the first parameter is surface motion or vibration of the liquid. .

:.: .

8. The safety device of any of claims 1 to 6, wherein the first parameter is underwater pressure changes with respect to the body of liquid. ë

9. The safety device of any of the preceding claims, further comprising an ë override mechanism that disables the safety device to enable the body of liquid to be used without setting off the device, said override mechanism comprising a time out means that reactivates the device after a set period of time.

10. The safety device of claim 9, wherein the time out means is arranged to reactivate the override mechanism after a set period of time during which no data is detected by the device.

11. The safety device of any of the preceding claims, wherein the device is powered by solar cells.

12. The safety device of any of the preceding claims, wherein the indicating means comprises at least one signalling means selected from the group containing: audible signal, visible signal and radio signal.

13. The safety device of any of the preceding claims, wherein the entire device is housed within a single vandal proof container.

14. A safety device for detecting the introduction and/or presence of a foreign body or object in or on a body of liquid as substantially described, with reference to the drawings, hereinbefore. .. . ë .. see. . :. I. V..