Broad field motion detector

• US 6,885,300 B1
• Filed: 06/05/2002
• Issued: 04/26/2005
• Est. Priority Date: 06/05/2002
• Status: Active Grant

• Current Assignee: The Watt Stopper Incorporated (Legrand SA)
• Original Assignee: The Watt Stopper Incorporated (Legrand SA)
• Inventors: Viala, Roar, Johnston, Kendall Ryan
• Primary Examiner(s): Lee, Benjamin C.
• Assistant Examiner(s): TANG, SON M
• Application Number:
  US10/163,409
• Time in Patent Office: 1,056 Days
• Field of Search: 340/541, 340/551, 340/552, 340/553, 340/554, 340/561, 340/565, 340/567
• US Class Current: 340/541
• CPC Class Codes: G08B 13/1618 using ultrasonic detection means

Abstract

A motion sensing system device and method which utilize dispersed ultrasonic radiation is disclosed. The system preferably comprises a low profile sensor unit configured to couple to a ceiling position. The sensor unit comprises an ultrasonic transmitter and an ultrasonic receiver and a pair of acoustic reflectors positioned in a transmitting path of the ultrasonic transmitter and a receiving path of the ultrasonic receiver for generating and detecting the ultrasonic radiation in a broadcast field. The acoustic reflectors preferably comprise cones, conical cross-sections and/or combinations thereof which are integral with the ultrasonic transmitter and the ultrasonic receiver and/or are coupled to a housing structure for positioning the acoustic reflectors in the transmitting and/or receiving paths. The sensor unit also preferably comprises a circuit for driving the transmitter and for detecting motion by detecting changes in the receiver signal. In further embodiments, the system also includes an infrared sensor and is configured to generate a response based on the combination of changes in the receiver signal and a signal form the infrared sensor.

Claims

1. A sensor comprising:

a. a motion sensor unit comprising a transmitter for emitting ultrasonic radiation and a receiver for detecting the ultrasonic radiation; and

b. an acoustic propagation modulator configured for dispersing the ultrasonic radiation emitted into broad field ultrasonic radiation and focusing the broad field ultrasonic radiation received to detect motion, the acoustic propagation modulator comprising acoustic reflectors positioned directly in a path of the transmitter and the receiver and coupled to the motion sensor unit, wherein the acoustic reflectors have sloped walls.

2. The sensor of claim 1, wherein the transmitter transmits ultrasonic radiation at a frequency of 20 Kilohertz or above.

3. The sensor of claim 1, further comprising a housing configured for coupling the motion sensor to a ceiling position.

4. The sensor of claim 3, wherein the acoustic propagation modulator is coupled to the housing.

5. The sensor of claim 1, wherein the motion sensor unit comprises a circuit in electrical communication with the transmitter and the receiver, the circuit being configured to drive the transmitter and generate a receiving signal from the receiver.

6. The sensor of claim 5, wherein the circuit is configured to generate a response when changes in the ultrasonic radiation are detected.

7. The sensor of claim 6, wherein the response includes at least one of sounding an alarm and initiating a telephone call.

8. The sensor of claim 1, wherein the acoustic reflectors comprise one or more conical cross-sections.

9. The sensor of claim 8, wherein the one or more conical cross-sections are concentrically positioned.

10. The sensor of claim 1, wherein the acoustic reflectors comprise cone members.

11. A motion detector comprising:

a. means for emitting a wide angle ultrasonic wave comprising;

i) an ultrasonic transmitter; and

ii) an acoustic reflector positioned in a transmitting path of the ultrasonic transmitter, wherein the acoustic reflector comprises concentrically positioned conical cross-sections for dispersing the ultrasonic radiation for the transmitter into the wide angle ultrasonic wave;

b. means for receiving the wide angle ultrasonic wave; and

c. means for detecting changes in the wide angle ultrasonic wave.

12. The detector of claim 11, wherein the means for receiving the wide angle ultrasonic wave comprises:

a. an ultrasonic receiver; and

b. a complementary acoustic reflector positioned in a receiving path of the ultrasonic receiver, such that the wide angle ultrasonic wave received is focused towards the receiver.

13. The detector of claim 12, wherein the acoustic reflector and the complementary acoustic reflector comprise one or more conical cross-sections.

14. The detector of claim 13, wherein the acoustic reflector and the complementary acoustic reflector comprise a cone member positioned centrally with respect to the one or more conical cross-sections.

15. The detector of claim 12, wherein the means for detecting changes in the wide angle ultrasonic wave comprises a circuit in electrical communication with the ultrasonic transmitter and the ultrasonic receiver, the circuit being configured to detect Doppler disturbances in the wide angle ultrasonic wave.

16. The detector of claim 11, further comprising an infrared sensor.

17. The detector of claim 11, wherein the means for emitting a wide angle ultrasonic wave emits ultrasonic radiation dispersed in a detection cone of 45 degrees or more.

18. The detector of claim 11, wherein the means for detecting changes in the wide angle ultrasonic wave comprises a circuit in electrical communication with the means for emitting and the means for receiving.

19. A motion detector unit for detecting motion in a room, the motion detector unit comprising:

a. a transmitter unit with an acoustic reflector positioned directly in a transmission path for producing a broad field detection signal;

b. a receiver unit with a matched acoustic reflector positioned directly in a detection path for receiving the broad field detection signal;

c. a circuit coupled to the transmitter and the receiver for monitoring changes in the detection signal; and

d. a housing for coupling to a ceiling of the room and detecting motion therefrom and for housing the transmitter and the receiver, wherein the acoustic reflector and the matched acoustic reflector are coupled to the housing and have sloped walls.

20. The motion detector of claim 19, wherein the acoustic reflector and the matched acoustic reflector are integral with the transmitter unit and the receiver unit, respectively.

21. A system comprising at least one motion detector, the at least one motion detector comprising one or more transducers comprising stationary acoustic modifiers, wherein the stationary acoustic modifiers disperse ultrasonic radiation generated by the one or more transducers into a wide angle ultrasonic wave and focus the wide angle ultrasonic wave received by the one or more transducers, wherein the stationary acoustic modifiers comprise conical sections in the path of the ultrasonic radiation transmitted and the wide angle ultrasonic wave received.

22. A method of detecting motion comprising:

a. generating a dispersed standing wave from a motion sensor unit using a stationary acoustic modulator in a detection area, wherein the stationary acoustic modulator disperses ultrasound radiation generated from an ultrasonic transmitter into broad field ultrasonic standing wave;

b. monitoring the dispersed standing wave using a matched stationary acoustic modulator from the motion sensor unit, wherein the matched stationary acoustic modulator focuses the dispersed standing wave to an ultrasound receiver; and

c. detecting changes between the dispersed standing wave, wherein the stationary acoustic modulators each comprises acoustic reflectors having sloped walls and positioned directly in a path of the corresponding transmitter and receiver, respectively.

23. The method of claim 22, wherein generating a dispersed standing wave comprises driving an ultrasound transmitter at a frequency of 20,000 Hz or higher in a path of the stationary acoustic reflector.

24. The method of claim 22, wherein monitoring the dispersed standing wave comprises sensing ultrasonic radiation with an ultrasonic receiver in a path of the matched acoustic reflector.

25. The method of claim 22, further comprising generating a response when detecting changes in the dispersed standing wave.