Intruder alarm with trajectory display

• US 5,966,074 A
• Filed: 12/16/1997
• Issued: 10/12/1999
• Est. Priority Date: 12/17/1996
• Status: Expired due to Fees

• Current Assignee: Keith M. Baxter
• Original Assignee: Keith M. Baxter
• Inventors: Baxter, Keith M.
• Primary Examiner(s): Wu, Daniel J.
• Assistant Examiner(s): TWEEL JR, JOHN ALEXANDER
• Application Number:
  US08/991,146
• Time in Patent Office: 665 Days
• Field of Search: 340/565, 340/552, 340/541, 340/556, 340/557, 348/144, 348/157, 348/169, 348/172, 348/159, 702/150, 702/151, 702/152
• US Class Current: 340/565
• CPC Class Codes: G08B 13/19602 Image analysis to detect motion of the intruder, e.g. by frame subtraction
• CPC Class Codes: G08B 13/19641 Multiple cameras having overlapping views on a single scene
• CPC Class Codes: G08B 13/19691 Signalling events for better perception by user, e.g. indicating alarms by making display brighter, adding text, creating a sound

Abstract

Image data obtained from cameras or the like of a monitored are abstracted into a set of trajectories which may be displayed and used for referencing images or activating alarms based on trajectory location, angle or speed.

Claims

1. An intruder alarm for a monitored area comprising:

(a) at least one optical sensor providing a plurality of signals indicating received light at different angles across the monitored area;

(b) a display screen; and

(c) an electronic computer receiving the plurality of presence signals and their angles and communicating with the display screen to operate according to a stored program to;

(i) detect changes in the received signals;

(ii) relate changes in the received signals to at least one region within the monitored area;

(iii) link the one region to other regions to describe at least one trajectories within the monitored area of an object moving within the monitored area; and

(iv) display the trajectory on the display screen.

2. The alarm system as recited in claim 1 wherein there are at least two sensors providing a first set and second set of presence signals at azimuthal angles.

3. The alarm system as recited in claim 1 wherein the electronic computer further compares the trajectories against alarm zones of particular regions and if the trajectory crosses into the alarm zone provides an alarm to a user.

4. The alarm system as recited in claim 3 wherein the electronic computer further compares the trajectories against alarm angles and if the trajectory crosses into the alarm zone and is at substantially the alarm angle, provides an alarm to a user.

5. The alarm system as recited in claim 3 wherein the electronic computer further compares the trajectories against alarm velocities and if the trajectory crosses into the alarm zone provides at an alarm velocity provides an alarm to the user.

6. The alarm system as recited in claim 1 wherein the alarm system includes a cursor control device, and wherein the alarm regions are entered into the electronic computer by being drawn by the user on the display screen with the user using the cursor control device.

7. The alarm system as recited in claim 1 wherein the electronic computer further displays the display screen outlines of landmark objects of the group consisting of:

buildings, vegetation, roads and sidewalks.

8. The alarm system as recited in claim 1 wherein the alarm system includes a cursor control device and wherein the electronic computer further displays on the display screen a clock face indicting a time at which the received signals of the trajectory were detected when the trajectory as displayed in selected by the cursor control device.

9. The alarm system as recited in claim 1 wherein the electronic computer sequentially displays the trajectory on the display screen in accelerated time sequence with other trajectories according to when received signals of the trajectories were detected.

10. The alarm system as recited in claim 1 wherein the electronic computer displays the trajectory on the display screen with other trajectories using different visual trajectory lines according to when the received signals of the trajectories were detected.

11. The alarm system as recited in claim 1 wherein the optical sensors acquire one dimensional image information providing presence signals at azimuthal angles.

12. The alarm system as recited in claim 1 wherein the optical sensors area image acquiring cameras.

13. The alarm system as recited in claim 1 including an electronic camera for capturing an image of at least a portion of the monitored area and wherein the electronic computer operates to capture images of the portion of the monitored area linked to the trajectories.

14. The alarm system as recited in claim 1 including an electronic camera for capturing an image of at least a portion of the monitored area and wherein the electronic computer steers the electronic camera to capture images of objects within the monitored area according to the trajectories.