Abstract: A multiple sensing technology-based occupancy sensor. Ultrasonic and infrared sensors are used to produce first and second occupancy estimator signals that are combined using a fusion based detection algorithm to produce a combined estimator signal. The combined estimator is then used to switch electrical loads when the combined estimator signal is above a predetermined threshold. The result is an occupancy sensor that has a very high probability of occupancy detection and a low probability of false tripping.

Abstract: A multiple sensing technology-based occupancy sensor. Ultrasonic and infrared sensors are used to produce first and second occupancy estimator signals that are combined using a fusion based detection algorithm to produce a combined estimator signal. The combined estimator is then used to switch electrical loads when the combined estimator signal is above a predetermined threshold. The result is an occupancy sensor that has a very high probability of occupancy detection and a low probability of false tripping.

Abstract: An occupancy sensor that provides improved performance by the inclusion of a microprocessor that controls the sensing transducers and processes the received signal to optimize desired detection performance. The occupancy sensor includes a quadrature detection technique and automatic sensitivity adjustment that reduce false detection caused by air flow, hallway traffic and other noise sources. A fault detection method executed periodically detects fault conditions in the sensor or sensing area caused by component failure or obstructions in front of the sensor. Transmitter power is varied depending on the size of the desired coverage area. Since various ambient parameters such as line voltage, light level, and temperature may be easily and usefully monitored, the microprocessor may use these variables to make intelligent decisions in controlling electrical loads, such as building lighting and ventilation.