초록 ▼

A dual sensing intrusion detection system has a microwave channel and a PIR channel. The signal from the microwave channel is amplified by an amplifier having a substantially constant gain, and is digitized and converted into a first digital signal. The signal from the PIR detector is amplified by a

A dual sensing intrusion detection system has a microwave channel and a PIR channel. The signal from the microwave channel is amplified by an amplifier having a substantially constant gain, and is digitized and converted into a first digital signal. The signal from the PIR detector is amplified by amplifier having a substantial constant gain and is digitized and converted into a second digital signal. The first and second digital signals are compared to a microwave threshold signal and a PIR threshold signal respectively to generate an alarm signal. The system has a thermistor to detect the ambient temperature. The PIR threshold signal can be adjusted based upon changes in static conditions from the output of the thermistor. In addition, the microwave threshold signal can be changed statically based upon long term trend of the first digitized signal. Finally, the PIR threshold signal and the microwave threshold signal can be changed based upon detection from the other respective channel due to dynamic changes in the environment.

대표청구항 ▼

An intrusion detection device for detecting an intruder in a volume of space, said device comprising: first sensing means for generating a first signal in response to the detection of the intruder; first amplifying means for receiving said first signal and for generating a first amplified signal; se

An intrusion detection device for detecting an intruder in a volume of space, said device comprising: first sensing means for generating a first signal in response to the detection of the intruder; first amplifying means for receiving said first signal and for generating a first amplified signal; second sensing means for generating a second signal in response to the detection of the intruder; second amplifying means for receiving said second signal and for generating a second amplified signal; digitizing means for digitizing said first and second amplified signals to produce first and second digitized signals, respectively; and processing means for receiving said first and second digitized signals and for comparing same to a first and a second threshold signal respectively, to generate a first and a second digital signal, respectively in the event said first and second digitized signals exceed said first and second threshold signals respectively, and for calculating a characteristic of said second digital signal, representing the energy of said second digital signal, and for dynamically adjusting said first threshold signal, in response to said characteristic calculated for said second digital signal, and for using said first and second digital signals in generating an alarm signal.