INTRUSION ALARM WITH SIGNAL PROCESSING AND CHANNEL IDENTIFICATION

• US 3,774,190 A
• Filed: 02/02/1972
• Issued: 11/20/1973
• Est. Priority Date: 02/02/1972
• Status: Expired due to Term

• Current Assignee: Geotronix Incorporated
• Original Assignee: William F. Kyle Jr
• Inventors: Kyle, William F. Jr.
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Swann, III, Glen R.
• Application Number:
  US05/222,745
• Time in Patent Office: 657 Days
• Field of Search: 340/258R,258D,261,276,224,225,147C
• US Class Current: 367/136
• CPC Class Codes: G08B 13/16 Actuation by interference with mechanical vibrations in air or other fluid
• CPC Class Codes: G08B 13/1663 using seismic sensing means
• CPC Class Codes: G08B 25/009 Signalling of the alarm condition to a substation whose identity is signalled to a central station, e.g. relaying alarm signals in order to extend communication range

Abstract

An intrusion detector employs a signal processor capable of not only recognizing the vibrational signature of a single intrusion event, but of recognizing a sequential pattern of the vibrations of a plurality of such events. A plurality of channels, each having sensor arrays at the inputs thereof, are connected to respective inputs of a common signal processor. An output is produced from the signal processor when the signal supplied thereto falls within prescribed limits. This output enables a respective channel to activate a tone code generator to produce an output having a group of frequencies corresponding to the particular channel. The modulated RF signal is then transmitted to a remote readout station. The signal processor recognizes the vibrations of each intrusion event and initiates a timer in response to the first of such events. Each subsequent event reinitiates the timing period of the timer until the full time period thereof has elapsed without the receipt of a subsequent pulse. A counter counts the number of such events, and if a predetermined count is achieved before an output is supplied by the timer, an alarm or similar indicator is actuated.

Claims

1. An intrusion detector comprising:

a. a plurality of channels each including at least one sensor, b. means in common with each of said sensors for processing signals from each of said sensors and providing a detection output when said signals are within prescribed limits, and c. output means responsive to outputs of each of said sensors and also to the output of said processing means for providing an indication of the particular one of said channels generating the signal which is within said prescribed limits.

2. An intrusion detector as defined in claim 1, wherein said output means includes a plurality of encoders, one for each of said channels and responsive to the output of respective sensors and said processing means for generating a distinct output, and a display responsive to the outputs of each of said encoders for providing a visual indication of the particular one of said channels generating the signal which is within said prescribed limits.

3. An intrusion detector as defined in claim 2, wherein said output means further includes a tone burst generator connected to the outputs of said encoders and having a distinct frequency output for each distinct output supplied thereto from said encoders, means for transmitting the output of said generator to a remote location, means at the remote location for receiving the transmitted output of said generator, and a decoder connected between said receiving means and said visual indication means.

4. An intrusion detector as defined in claim 3, wherein each of said encoders produces a distinct digitally coded output, and further comprising means for activitating said encoders to repeat the coded output a predetermined number of times after initiation thereof.

5. An intrusion detector as defined in claim 1, wherein said signal is in the form of a series of damped oscillations with all but the first thereof being spaced from a preceding one by no more than a predetermined timing period, and wherein said signal processing means includes a timer responsive to each of said oscillations for producing an output at the end of said timing period following receipt thereof in the absence of the receipt of a subsequent oscillation, means responsive to said signal for counting the oscillations which occur before an output is produced by said timer, and means responsive to a predetermined count in said counting means for producing said detection output.

6. An intrusion detector as defined in claim 5, wherein said output means includes a plurality of encoders, one for each of said channels and responsive to the output of respective sensors and said processing means for generating a distinct output, and a display responsive to the output of each of said encoders for providing a visual indication of the particular one of said channels generating the signal which is within said presecirbed limits.

7. An intrusion detector as defined in claim 6, wherein said output means further includes a tone burst generator connected to the outputs of said encoders and having a distinct frequency output for each distinct output supplied thereto from said encoders, means fOr transmitting the output of said generator to a remote location, means at the remote location for receiving the transmitted output of said generator, and a decoder connected between said receiving means and said visual indication means.

8. A signal processor for an intrusion detector which is adapted for connection between one or more sensors and an indication device and wherein the signals from the sensors are in the form of a series of damped oscillations with all but the first thereof being spaced from a preceding one by no more than a predetermined timing period, comprising a. a timer responsive to each of said oscillations for producing an output at the end of said timing period following receipt thereof in the absence of the receipt of a subsequent oscillation. b. means responsive to said signal for counting the oscillations which occur before an output is produced by said timer, and c. means responsive to a predetermined count in said counting means for producing an output to the indication device.

9. A signal processor as defined in claim 8, further comprising means connected between the sensors and said timer for passing signals having a frequency within a predetermined range which encompasses the frequency of the vibrations caused by a footstep.

10. A signal processor as defined in claim 9, further comprising an integrator connected to an output of the sensors, and a level detector connected between an output of said integrator and an input of said timer.

11. A signal processor as defined in claim 8, further comprising an integrator connected to an output of the sensors, and a level detector connected between an output of said integrator and an input of said timer.