DIRECTION OF TRAVEL MOTION SENSOR

• US 20090224913A1
• Filed: 09/26/2007
• Published: 09/10/2009
• 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.
• Granted Patent: US 7,777,624 B2
• Time in Patent Office: Days
• 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:

monitoring said protected area using a microwave (MW) motion detector that generates a plurality of MW Doppler signals upon detection of motion;

comparing the generated plurality of MW Doppler signals to a predetermined signal threshold, wherein if each said plurality of MW Doppler signals is less than the threshold signal storing each said MW Doppler signal in non-volatile memory;

averaging each said plurality of MW Doppler signal stored in said non-volatile memory and generating a moving average with each said received plurality of MW Doppler signal, wherein if the moving average MW Doppler signal is increasing or decreasing generating an alarm indicating said intruder in said protected area.

2. The A method of sensing the direction of travel of an intruder in a protected area of claim 1, wherein the step of comparing the generated plurality of MW Doppler signals includes the step of:

comparing each said plurality of 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 PIR motion detector generating an alarm.

3. The A method of sensing the direction of travel of an intruder in a protected area of claim 2, wherein the plurality of MW Doppler signals are updated periodically and compared with the stored Doppler signal to a subsequent Doppler signal 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 monitoring said protected area using a microwave (MW) motion detector 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 PIR sensor and a microwave sensor detect 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:

monitoring said protected area using a microwave (MW) motion detector that generates a plurality of MW Doppler signals upon detection of motion;

comparing the generated plurality of MW Doppler signals to a predetermined signal threshold, wherein if each said plurality of MW Doppler signals is less than the threshold signal storing each said MW Doppler signal in non-volatile memory;

averaging each said plurality of MW Doppler signal stored in said non-volatile memory and generating a moving average with each said received plurality of MW Doppler signal, wherein if the moving average MW Doppler signal is increasing or decreasing generating an alarm indicating said intruder in said protected area.