Swimming pool alarm

• US 5,959,534 A
• Filed: 11/04/1997
• Issued: 09/28/1999
• Est. Priority Date: 10/29/1993
• Status: Expired due to Fees

• Current Assignee: Splash Industries Incorporated
• Original Assignee: Splash Industries Incorporated
• Inventors: Shaw, William S., Nixon, Michael, Campbell, Stephen Harold, Dupont, Lee Pierre Jr., Saxon, George Zane
• Primary Examiner(s): Lee, Benjamin C.
• Application Number:
  US08/963,998
• Time in Patent Office: 693 Days
• Field of Search: 340/553, 340/573.1, 340/573.4, 340/573.6, 367/93, 367/94
• US Class Current: 340/573.6
• CPC Class Codes: G01V 1/001 Acoustic presence detection
• CPC Class Codes: G08B 21/082 by monitoring electrical characteristics of the water

Abstract

A method and apparatus for detecting unauthorized or accidental entry of an object into a body of water is disclosed, wherein the frequency or frequency range of sound waves in a body of water generated by the entry of the object into the body of water is determined. Then the sound waves having the frequency generated in the body of water are detected and an electrical output waveform representative of the amplitude of the sound wave in the frequency is generated. The amplitude of the electrical output waveform is subsequently averaged, so that an alarm signal is generated when the amplitude of the electrical output waveform exceeds the averaged amplitude by a predetermined value in a predetermined period of time. Once the alarm signal is generated an alarm is activated.

Claims

1. A method of detecting entry of an object into a body of water, comprising the steps of:

establishing a standing wave in the body of water;

separating from the standing wave a sound wave having a predetermined frequency that is expected to occur when the object enters the body of water;

producing two electrical signals having amplitudes related to the amplitude of the sound wave, at least one of which represents an average of the amplitude of the sound wave;

detecting when the amplitude of one of the electrical signals exceeds the amplitude of the other electrical signal by a predetermined amount; and

thereafter

generating an alarm signal that is used to activate an alarm.

5. The method of claim 1, additionally comprising the step of:

transmitting the alarm signal to a remote system in order to activate a remote alarm.

6. The method of claim 1, wherein the body of water is a pool and additionally comprising the steps of:

identifying the activation of a pool pump; and

disabling the alarm when the pool pump is activated.

7. The method of claim 1, wherein the body of water is a pool and additionally comprising the steps of:

identifying the activation of a pool sweep; and

disabling the alarm signal when the pool sweep is activated.

8. The method of claim 1, additionally comprising the step of rectifying the sound wave.

33. The method of claim 1 wherein both electrical signals represent an average of the amplitude of the sound wave.

34. The method of claim 33 wherein producing the two electrical signals comprises averaging the amplitude of the sound wave with two averaging circuits having different time constants.

35. The method of claim 1 further comprising detecting a predetermined number of slope changes in the sound wave in a predetermined period of time.

36. The method of claim 35 further comprising activating the alarm only after the alarm signal has been generated and the predetermined number of slope changes have been detected in the predetermined period of time.

2. A method of detecting entry of an object into a body of water, comprising the steps of:

transmitting a controlled sound wave into the body of water to set up a standing wave;

detecting a sound wave having a predetermined frequency that is expected to occur when the object enters the body of water, the predetermined frequency being different than the frequency of the controlled sound wave;

filtering the controlled sound wave from the detected sound wave;

producing two electrical signals having amplitudes related to the amplitude of the detected sound wave, at least one of which represents an average of the amplitude of the detected sound wave;

detecting when the amplitude of one of the electrical signals exceeds the amplitude of the other electrical signal by a predetermined amount; and

thereafter

generating an alarm signal that is used to activate an alarm.

3. The method of claim 2, wherein the controlled sound wave is of an ultrasonic frequency.

4. The method of claim 2, wherein the transmitting and detecting of sound waves is performed by a single transducer.

9. A method of detecting entry of an object into a body of water, comprising the steps of:

establishing a standing wave in the body of water;

separating from the standing wave a sound wave having a component in a predetermined range of frequencies expected to occur when the object enters the body of water;

producing two electrical signals having amplitudes related to the amplitude of the sound wave, at least one of which represents an average of the amplitude of the sound wave;

detecting when the amplitude of one of the electrical signals exceeds the amplitude of the other electrical signal by a predetermined amount; and

thereafter

generating an alarm signal that is used to activate an alarm.

12. The method of claim 9 additionally comprising the step of rectifying the detected sound wave.

10. A method of detecting entry of an object into a body of water, comprising the steps of:

transmitting a controlled sound wave into the body of water to set up a standing wave;

detecting a sound wave having a component in a predetermined range of frequencies expected to occur when the object enters the body of water, the predetermined range of frequencies excluding the frequency of the controlled sound wave;

producing two electrical signals having amplitudes related to the amplitude of the detected sound wave in the predetermined frequency range, at least one of which represents an average of the amplitude of the detected sound wave;

filtering the controlled sound wave from the detected sound wave;

detecting when the amplitude of one of the electrical signals exceeds the amplitude of the other electrical signal by a predetermined amount; and

thereafter

generating an alarm signal that is used to activate an alarm.

11. The method of claim 10, wherein the transmitting and detecting of sound waves is performed by a single transducer.

13. An apparatus for detecting entry of an object into a body of water, comprising:

a transmitter to establish a standing wave in the body of water;

a sound wave detector for separating from the standing wave a sound wave having at least one predetermined frequency expected to occur when the object enters the body of water and for producing an electrical output waveform representing the detected sound wave;

a rectifier electrically connected to the sound wave detector for rectifying the electrical output waveform;

an integrator/comparator electrically connected to the rectifier for producing two electrical signals having amplitudes related to the amplitude of the electrical output waveform, at least one of which represents an average of the amplitude of the electrical output waveform, and for generating an alarm signal when the amplitude of one of the electrical signals exceeds the amplitude of the other electrical signal by a predetermined amount; and

an alarm electrically connected to the integrator/comparator that is activated in response to the alarm signal.

16. The apparatus of claim 13, additionally comprising:

a processing means interposed between the integrator/comparator and the alarm for activating the alarm in response to the alarm signal.

14. An apparatus for detecting entry of an object into a body of water, comprising:

a signal generator for transmitting a controlled sound wave into the body of water to set up a standing wave;

a sound wave detector for receiving a sound wave having at least one predetermined frequency expected to occur when the object enters the body of water, the predetermined frequency being different than the frequency of the standing wave, and for producing an electrical output waveform representing the detected sound wave;

a rectifier electrically connected to the sound wave detector for rectifying the electrical output waveform;

a filter for removing the controlled sound wave from the electrical output waveform;

an integrator/comparator electrically connected to the rectifier for producing two electrical signals having amplitudes related to the amplitude of the electrical output waveform, at least one of which represents an average of the amplitude of the electrical output waveform, and for generating an alarm signal when the amplitude of one of the electrical signals exceeds the amplitude of the other electrical signal by a predetermined amount; and

an alarm electrically connected to the integrator/comparator that is activated in response to the alarm signal.

15. The apparatus of claim 14, wherein the sound wave detector and the signal generator are the same transducer.

17. An apparatus for detecting entry of an object into a body of water, comprising:

a transmitter to establish a standing wave in the body of water;

a sound wave detector for separating from the standing wave a sound wave having at least one predetermined frequency expected to occur when the object enters the body of water and for producing an electrical output waveform representing the detected sound wave;

a processing means electrically connected to the sound wave detector for producing two electrical signals having amplitudes related to the amplitude of the electrical output waveform, a first one of which represents an average of the amplitude of the electrical output waveform, and for producing an alarm signal when amplitude of one of the electrical signals exceeds the amplitude of the other electrical signal by predetermined amount; and

an alarm electrically connected to the processing means that is activated in response to the alarm signal.

18. The apparatus of claim 17, additionally comprising

a rectifier interposed between the sound wave detector and the processing means for rectifying the electrical output waveform.

37. The apparatus of claim 17 wherein both electrical signals represent an average of the amplitude of the electrical output waveform.

38. The apparatus of claim 17 further comprising a slope change detector that detects a predetermined number of slope changes in the electrical output waveform in a predetermined period of time.

39. The apparatus of claim 38 wherein the alarm is activated only after the alarm signal has been generated and the predetermined number of slope changes have been detected in the predetermined period of time.

19. An apparatus for detecting entry of an object into a body of water, comprising:

a transmitter to establish a standing wave in the body of water;

sound wave detecting means for separating from the standing wave a sound wave having at least one predetermined frequency expected to occur when the object enters the body of water;

signal output means connected to the sound wave detecting means for producing an electrical output waveform representing the detected sound wave;

averaging means connected to the signal output means for producing two electrical signals having amplitudes related to the amplitude of the electrical output waveform, at least one of which represents an average of the amplitude of the electrical output waveform, and for producing an alarm signal when the amplitude of one of the electrical signals exceeds the amplitude of the other electrical signal by a predetermined amount; and

alarm activation means connected to the averaging means for activating an alarm in response to the alarm signal.

20. The apparatus of claim 19, wherein the averaging means comprises:

a rectifier and an integrator/comparator.

21. The apparatus of claim 19, wherein the averaging means comprises:

a processor.

22. A method of detecting entry of an object into a body of water, comprising the steps of:

transmitting a sound wave into the body of water to set up a standing wave that is disturbed when the object enters the body of water;

detecting the disturbed sound wave and producing an electrical output waveform indicating the amplitude and frequency of the disturbed sound wave;

producing two electrical signals having amplitudes related to the amplitude of the electrical output waveform, at least one of which represents an average of the amplitude of the electrical output waveform;

generating an alarm signal when the amplitude of one of the electrical signals exceeds the amplitude of the other electrical signal by a predetermined amount, indicating the entry of the object into the body of water; and

activating an alarm in response to the alarm signal.

23. The method of claim 22, wherein producing the two electrical signals comprises the step of continuously integrating the electrical output waveform to produce at least one of the electrical signals.

24. The method of claim 22, additionally comprising the steps of:

monitoring the electrical output waveform to detect when the frequency of the electrical output waveform reaches a predetermined frequency indicating the entry of the object into the body of water; and

activating the alarm only when the alarm signal has been generated and the frequency of the electrical output waveform reaches the predetermined frequency.

25. The method of claim 24, wherein the predetermined frequency is represented by:

a predetermined number of slope changes in the electrical output waveform detected within a predetermined time period.

26. The method of claim 22, wherein activating the alarm comprises the step of:

transmitting the alarm signal to a remote system in order to activate a remote alarm.

27. The method in accordance with claim 22, wherein the sound wave is of an ultrasonic frequency.

28. The method of claim 22, additionally comprising the step of rectifying the electrical output waveform.

40. The method of claim 22 wherein both electrical signals represent an average of the amplitude of the electrical output waveform.

41. The method of claim 40 wherein producing the two electrical signals comprises averaging the amplitude of the electrical output waveform with two averaging circuits having different time constants.

42. The method of claim 22 further comprising detecting a predetermined number of slope changes in the electrical output waveform in a predetermined period of time.

43. The method of claim 42 further comprising activating the alarm only after the alarm signal has been generated and the predetermined number of slope changes have been detected in the predetermined period of time.

29. An apparatus for detecting entry of an object into a body of water, comprising:

means for transmitting a sound wave into the body of water to set up a standing wave that is disturbed when the object enters the body of water;

means for detecting the disturbed sound wave and for producing an electrical output waveform representing the disturbed sound wave;

means for producing two electrical signals having amplitudes related to the amplitude of the electrical output waveform, at least one of which represents an average of the amplitude of the electrical output waveform;

means for generating an alarm signal when the amplitude of one of the electrical signals exceeds the amplitude of the other electrical signal by a predetermined amount, indicating the entry of the object into the body of water; and

means for activating an alarm in response to the alarm signal.

30. The apparatus of claim 29, wherein the means for producing the two electrical signals comprises:

a rectifier and an integrator.

31. The apparatus of claim 29, wherein the means for producing the two electrical signals comprises:

a processor.

44. The apparatus of claim 29 wherein both electrical signals represent an average of the amplitude of the electrical output waveform.

45. The apparatus of claim 29 further comprising means for detecting a predetermined number of slope changes in the electrical output waveform in a predetermined period of time.

46. The apparatus of claim 45 wherein the means for activating the alarm actually activates the alarm only after the alarm signal has been generated and the predetermined number of slope changes have been detected in the predetermined period of time.

32. An apparatus for detecting entry of an object over a predetermined size into a body of water, comprising:

a signal generator for transmitting a sound wave into the body of water to set up a standing wave that is disturbed when the object enters the body of water;

a sound wave detector for receiving the disturbed sound wave and producing an electrical output waveform indicating the amplitude and frequency of the disturbed sound wave;

processing means electrically connected to the sound wave detector for producing two electrical signals having amplitudes related to the amplitude of the electrical output waveform, at least one of which represents an average of the amplitude of the electrical output waveform, and for detecting when the amplitude of one of the electrical signals exceeds the amplitude of the other electrical signal by a predetermined amount, indicating the entry of the object into the body of water; and

an alarm electrically connected to the processing means that is activated in response to the alarm signal.