Dynamic alarm sensitivity adjustment and auto-calibrating smoke detection for reduced resource microprocessors
First Claim
1. A hazardous condition detection system, comprising,a housing containing a sensor package, the sensor package containing a hazardous condition sensor, the hazardous condition sensor being exposed to the ambient environment and taking periodic readings of the ambient environment;
- an alarm circuit coupled to the sensor package and disposed in the housing;
a microprocessor coupled to the alarm circuit, the microprocessor having a memory storage device containing a clean air reading and a plurality of alarm thresholds differential values, each of the plurality of alarm thresholds differential values being associated with a predetermined set of sensor readings indicative of a hazardous condition in the ambient environment,where said microprocessor periodically receives a raw sensor reading from the sensor package and preprocesses said received raw sensor reading using at least three distinctive filtering constants to generate a set of at least three conditioned sensor readings from each raw sensor reading received and where said microprocessor accumulates a plurality of sets of conditioned sensor readings, and selects an alarm threshold differential value from a plurality of stored alarm thresholds differential values based on the rate of change of the conditioned sensor readings in a first subset of accumulated conditioned sensor readings generated from a common filtering constant, and generates an alarm threshold from the selected alarm threshold differential value.
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Accused Products
Abstract
A hazardous condition detection system with a sensor package employing a reduced resource microprocessor capable of dynamic alarm sensitivity adjustment having volatile and non-volatile memory which receives periodic raw sensor readings from the sensor package and preprocesses each received periodic raw sensor reading by employing at least three distinctive filtering constants which are compared to alarm thresholds stored in memory to generate an alarm condition signal when ionization levels in the ambient environment exceed stored thresholds.
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Citations
20 Claims
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1. A hazardous condition detection system, comprising,
a housing containing a sensor package, the sensor package containing a hazardous condition sensor, the hazardous condition sensor being exposed to the ambient environment and taking periodic readings of the ambient environment; -
an alarm circuit coupled to the sensor package and disposed in the housing; a microprocessor coupled to the alarm circuit, the microprocessor having a memory storage device containing a clean air reading and a plurality of alarm thresholds differential values, each of the plurality of alarm thresholds differential values being associated with a predetermined set of sensor readings indicative of a hazardous condition in the ambient environment, where said microprocessor periodically receives a raw sensor reading from the sensor package and preprocesses said received raw sensor reading using at least three distinctive filtering constants to generate a set of at least three conditioned sensor readings from each raw sensor reading received and where said microprocessor accumulates a plurality of sets of conditioned sensor readings, and selects an alarm threshold differential value from a plurality of stored alarm thresholds differential values based on the rate of change of the conditioned sensor readings in a first subset of accumulated conditioned sensor readings generated from a common filtering constant, and generates an alarm threshold from the selected alarm threshold differential value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for selecting an alarm threshold for a hazardous condition detector characterized by the method steps of:
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associating a first alarm threshold differential value with a first predetermined set of ionization levels, and a second alarm threshold differential value with a second predetermined set of ionization levels; generating a first alarm threshold value from the first alarm threshold differential value; designating the first generated alarm threshold value as the current alarm threshold; receiving periodic raw sensor readings of the ionization level in the ambient environment from a sensor package; preprocessing each received periodic raw sensor reading and generating a set of conditioned sensor readings for each received periodic raw sensor reading; accumulating a plurality of sets of conditioned sensor readings; generating a first subset of conditioned sensor readings by selecting a first conditioned sensor reading from each of a plurality of accumulated sets of conditioned sensor readings; generating a second subset of conditioned sensor readings by selecting a second conditioned sensor reading from each of a plurality of accumulated sets of conditioned sensor readings; comparing the second subset of the conditioned sensor readings with the second predetermined set of ionization levels associated with the second alarm threshold differential value with a microprocessor; if the second subset of conditioned sensor readings are within the ionization levels specified in the second predetermined set of ionization levels, selecting the second alarm threshold differential value, generating a second alarm threshold value from the selected second alarm threshold differential value, and designating the second alarm threshold value as the current alarm threshold; comparing the current alarm threshold with a third conditioned sensor selected from the newest set of conditioned sensor readings; and designating an alarm event if the third conditioned sensor reading is in violation of the current alarm threshold. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification