Methods and apparatus for intrusion detection having improved immunity to false alarms

A method of detecting an intrusion within a volume of space comprising the steps of:

• detecting an intrusion within a volume of space by a first physical phenomenon;
• generating a first signal in response to the detection of said intrusion by said first physical phenomenon;
• detecting an intrusion within said volume of space by a second physical phenomena, different from the first phenomena;
• generating a second signal in response to the detection of said intrusion by said second physical phenomena;
• generating an alarm signal in response to the occurrence of one first signal and one second signal within a first interval, the occurrence of another first signal within a second interval said second interval subsequent to said first interval, and the occurrence of another second signal within a third interval said third interval subsequent to said second interval.

An intrusion detection system comprising:

• a first sensor for sensing an intrusion in a volume of space by a first physical phenomenon and for generating a first signal in response to the detection of said intrusion;
• a second sensor for sensing an intrusion in said volume of space by a second physical phenomenon different from the first phenomenon, for generating a second signal in response to the detection of said intrusion;
• and
• a microcontroller for generating an alarm signal in response to the occurrence of one first signal and one second signal within a first interval, the occurrence of another first signal within a second interval said second interval subsequent to said first interval, and the occurrence of another second signal within a third interval said third interval subsequent to said second interval.

A method of detecting an intrusion within a volume of space comprising the steps of:

• detecting an intrusion within a volume of space by a first physical phenomenon;
• generating a first signal in response to the detection of said intrusion by said first physical phenomenon;
• detecting an intrusion within said volume of space by a second physical phenomena, different from the first phenomena;
• generating a second signal in response to the detection of said intrusion by said second physical phenomena;
• generating an alarm signal in response to the occurrence of at least one first signal and at least one second signal within a first interval, the occurrence of one of another first signal and another second within a second interval said second interval subsequent to said first interval, and the occurrence of one of another first signal and another second signal within a third interval said third interval subsequent to said second interval.

An intrusion detection system comprising:

• a first detecting means for detecting an intrusion in a volume of space by a first physical phenomenon and for generating a first signal in response to each detection of said intrusion;
• a second detecting means for detecting an intrusion in said volume of space by a second physical phenomenon different from the first physical phenomenon and for generating a second signal in response to the detection of said intrusion;
• and
• logic means for generating an alarm signal in response to the occurrence of one first signal in response to one detection and one second signal in response to one detection within a first interval of time;
• and the logic means also generating an alarm signal in response to the occurrence of a plurality of first signals generated within a second interval of time.

A method of detecting an intrusion within a volume of space comprising the steps of:

• detecting an intrusion within a volume of space by s first physical phenomenon;
• generating a first signal in response to the detection of said intrusion by said first physical phenomenon;
• detecting an intrusion within said volume of space by a second physical phenomenon;
• generating a second signal in response to the detection of said intrusion by said second physical phenomenon;
• generating an alarm signal in response to the occurrence of one first signal and one second signal within a first interval of time;
• and
• generating an alarm signal in response to the occurrence of a plurality of first signals generated within a second interval of time.

An intrusion detection system comprising:

• a first sensor for sensing an intrusion in a volume of space by a first physical phenomenon and for generating a first signal in response to the detection of said intrusion;
• a second sensor for sensing an intrusion in said volume of space by a second physical phenomenon different from the first physical phenomenon and for generating a second signal in response to the detection of said intrusion;
• and
• a microcontroller for generating an alarm signal in response to the occurrence of one first signal and one second signal in response to one detection within a first interval of time;
• and the microcontroller also generating an alarm signal in response to the occurrence of a plurality of first signals generated within a second interval of time.

A method of detecting an intrusion within a volume of space comprising the steps of:

• detecting an intrusion within a volume of space by s first physical phenomenon;
• generating s first signal in response to the detection of said intrusion by said first physical phenomenon;
• detecting an intrusion within said volume of space by a second physical phenomenon, different from the first phenomenon;
• generating a second signal in response to the detection of said intrusion by said second physical phenomenon;
• generating an alarm signal in response to the occurrence of at least one first signal and at least one second signal within a first interval of time;
• and
• generating an alarm signal in response to the occurrence of a plurality of first signals generated within a second interval of time.