Pool monitoring

• US 7,019,649 B2
• Filed: 07/21/2005
• Issued: 03/28/2006
• Est. Priority Date: 10/30/2003
• Status: Expired due to Fees

• Current Assignee: Aquasonus LLC
• Original Assignee: Aquasonus LLC
• Inventors: Hoenig, Robert
• Primary Examiner(s): Mullen, Jr., Thomas J.
• Assistant Examiner(s): Hunnings, Travis
• Application Number:
  US11/187,646
• Publication Number:
  US 20050258969A1
• Time in Patent Office: 250 Days
• Field of Search: 340/566, 340/573.6, 340/531, 340/539, 340/539.1, 367/199, 367/136, 367/157
• US Class Current: 340/566
• CPC Class Codes: G08B 21/082 by monitoring electrical characteristics of the water
• CPC Class Codes: G08B 29/185 Signal analysis techniques for reducing or preventing false alarms or for enhancing the reliability of the system

Abstract

A pool monitoring system includes a hydrophone configured to generate an electrical signal in response to receiving a pressure wave in the liquid of a pool, and a processor configured to receive the electrical signal and generate a trigger signal, when the electrical signal includes a characteristic signature over a time period within a predetermined range of time periods.

Claims

1. A pool monitoring system comprising:

a hydrophone configured to generate an electrical signal in response to receiving a sound pressure wave in the liquid of a pool; and

a processor configured to

receive the electrical signal;

measure a time period over which the electrical signal includes a characteristic signature associated with entry of an object into the liquid of the pool; and

generate a trigger signal, when the measured time period is within a predetermined range of time periods.

2. The system of claim 1 wherein the processor is further configured to determine a trigger level from a background noise level.

3. The system of claim 2 wherein the processor determines the trigger level by setting a gain of an electrical circuit based on background noise in the electrical signal.

4. The system of claim 1 wherein the predetermined range of time periods consists of time periods less than 4 seconds.

5. The system of claim 1 wherein the predetermined range of time periods consists of time periods greater than 0.5 seconds.

6. The system of claim 1 wherein the hydrophone comprises a piezo-electric material composed of lead zirconate titanate ceramic or polyvinylidene fluoride polymer film.

7. The system of claim 1 further comprising:

a poolside horn configured to generate a sound in response to the trigger signal;

a first antenna configured to periodically send radio-frequency status signals;

one or more monitor units which include a second antenna configured to receive the radio-frequency status signals; and

a monitor horn configured to generate a sound in response to the trigger signal.

8. The system of claim 7 wherein the monitor units are configured to indicate reception of the radio-frequency status signals.

9. A pool intrusion detection method comprising:

generating an electrical signal in response to receiving a sound pressure wave in the liquid of a pool;

measuring a time period over which the electrical signal includes a characteristic signature associated with entry of an object into the liquid of the pool; and

generating a trigger signal in response to receiving the electrical signal when the measured time period is within a predetermined range of time periods.

10. The method of claim 9 further comprising determining a trigger level from a background noise level.

11. The method of claim 9 wherein the predetermined range of time periods consists of time periods less than 4 seconds.

12. The method of claim 9 wherein the predetermined range of time periods consists of time periods greater than 0.5 seconds.

13. The method of claim 9 further comprising generating a sound in response to the trigger signal.