Direction of travel motion sensor

• US 7,777,624 B2
• Filed: 09/26/2007
• Issued: 08/17/2010
• Est. Priority Date: 09/26/2007
• Status: Active Grant

• Current Assignee: Ademco Inc. (Resideo Technologies, Inc.)
• Original Assignee: Honeywell International Inc.
• Inventors: Wu, Xiaodong, Helland, James N., Green, Leslie K.
• Primary Examiner(s): Wu; Daniel
• Assistant Examiner(s): Thompson; Bradley E
• Application Number:
  US11/862,078
• Publication Number:
  US 20090224913A1
• Time in Patent Office: 1,056 Days
• Field of Search: 340/554, 367/93, 342/28
• US Class Current: 340/554
• CPC Class Codes: G01S 13/56 for presence detection presence detection using near field arrangements G01V3/00, e.g. G01V3/08, G01V3/12; burglar, theft or intruder alarms with electrical actuation G08B13/22 - G08B13/26
• CPC Class Codes: G01S 13/62 Sense-of-movement determination G01S13/589 takes precedence
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder

Abstract

A microwave direction of travel detector and method of detecting the direction of an intruder in a protected region. The microwave direction of travel detector transmits and receives, by a microwave transceiver a microwave signal directed toward a protected area. The microwave return signal is modulated by a moving target to produce a Doppler signal. The microcontroller monitors the output of the amplifier chain and stores the signal and compares it with previously stored signals. If the amplitude is increasing or decreasing over a preset time period, this would indicate that the target it approaching or receding respectively and an alarm would be generated by the microcontroller.

Claims

1. A method of sensing the direction of travel of an intruder in a protected area, said method comprising the steps of:

a microwave (MW) motion detector transmitting a microwave signal toward a protected area;

the microwave (MW) motion detector receiving a MW Doppler signal reflected from a target in the protected area;

comparing the received MW Doppler signal to a predetermined threshold, wherein, if the MW Doppler signal is less than the threshold signal, storing the MW Doppler signal in non-volatile memory; and

averaging all MW Doppler signals stored in said non-volatile memory and generating a moving average as new MW Doppler signals are received, wherein, if the moving average is increasing or decreasing generating an alarm indicating said intruder in said protected area.

2. The method of sensing the direction of travel of an intruder in a protected area of claim 1, wherein the step of comparing the received MW Doppler signal to a predetermined threshold includes the step of:

comparing each said received MW Doppler signal with the output of a PIR sensor to determine if said alarm should be triggered, wherein if both the MW motion detector and the PRI sensor detect motion, generating an alarm.

3. The method of sensing the direction of travel of an intruder in a protected area of claim 2, wherein a MW Doppler signal is received periodically and compared with the moving average to determine if the signal is getting stronger or weaker indicating an approaching target or a receding target.

4. The method of sensing the direction of travel of an intruder in a protected area of claim 1, wherein said step of receiving a MW Doppler signal includes the steps of either parallel sampling of gain information collected from the output of each stage of a plurality of cascading amplifiers or series sampling the feedback of a plurality of variable gain amplifiers.

5. The method of sensing the direction of travel of an intruder in a protected area of claim 1, wherein said direction of travel detection method operates in two modes;

a first mode, wherein an alarm is triggered if both a PRI sensor and a microwave sensor detector motion; and

a second mode, wherein an alarm is triggered if said microwave sensor detects motion and a direction of travel of said target.

6. The direction of travel detection method of claim 5, wherein the microwave sensor can identify said intruder in different zones.

7. A computer program storage device, readable by machine, tangibly embodying a program of instructions executable by a machine for sensing the direction of travel of an intruder in a protected area by a dual technology sensor, said method comprising the steps of:

a microwave (MW) motion detector transmitting a microwave signal toward a protected area;

the microwave (MW) motion detector receiving a MW Doppler signal reflected from a target in the protected area;

comparing the received MW Doppler signal to a predetermined threshold, wherein, if the MW Doppler signal is less than the threshold signal, storing the MW Doppler signal in non-volatile memory;

averaging all MW Doppler signals stored in said non-volatile memory and generating a moving average as new MW Doppler signals are received, wherein, if the moving average is increasing or decreasing generating an alarm indicating said intruder in said protected area.