Filing Information

Inventor(s)	Douglas D. Myron · Errol R. Williams · Charles C. Hardin · Timothy W. Woytek · Michael A. Stephens ·
Assignee(s)	MyTech Corporation ·  View assignee updates
Attorney/Agent(s)	Arnold, White & Durkee ·
Primary Examiner	Thomas Mullen ·
Application Number	US8384580
Filing date	02/06/1995
Issue date	06/17/1997
Predicted expiration date	02/06/2015
U.S. Classifications	340/541  · 250/DIG.1  ·
International Classifications	G08B 1300  ·
Kind Code	A
International Classifications	340565;567;541;552;554;511;516;553 ·

Patent Family

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.

Independent Claims | See all claims (55)

1. 1. An occupancy sensor-based load controller, comprising:sensing means for transmitting acoustic energy into a space, and for receiving acoustic energy reflected from said space to produce a detector signal indicative of said space;an analog-to-digital converter, connected to said sensing means, for digitizing said detector signal to produce a digitized detector signal having digital values indicative of said detector signal at controllable sampling intervals;a programmed microprocessor, connected to said analog-to-digital converter, to receive said digitized detector signal, and operable to analyze said digitized detector signal to assess a Doppler shift between said transmitted acoustic energy and said received acoustic energy and to provide an indication of motion within said space as a function of said Doppler shift; anda controllable load energizing device, responsive to said indication of motion, operable to automatically energize and de-energize an electrical load as a function of said indication of motion.
2. 17. A method of controlling an electrical load as a function of occupancy of a space, comprising:transmitting acoustic energy into a space;receiving acoustic energy reflected from said space;generating a detector signal indicative of said space as a function of said received acoustic energy;digitizing said detector signal to produce a series of digital samples indicative of said detector signal at controllable sampling intervals;processing said series of digital samples to assess a Doppler Shift between said transmitted acoustic energy and said received acoustic energy and to produce a signal indicative of occupancy of said space as a function of said Doppler shift; andautomatically energizing and de-energizing an electrical load as a function of said signal indicative of occupancy.
3. 39. A method of controlling an electrical load as a function of an occupancy pattern of a space, comprising:transmitting acoustic energy into a space;receiving acoustic energy reflected from said space;generating a detector signal indicative of said space as a function of said received acoustic energy;digitizing said detector signal to produce a series of digital samples indicative of said detector signal at controllable sampling intervals;processing said series of digital samples using a plurality of predetermined algorithms to produce a signal indicative of occupancy of said space;automatically modifying said predetermined algorithms to adjust said processing step as a function of a history of said signal indicative of occupancy; andautomatically energizing and de-energizing an electrical load as a function of said signal indicative of occupancy.
4. 47. A method of controlling an electrical load as a function of an occupancy pattern of a space, comprising:detecting infrared energy within a space;generating a detector signal indicative of said space as a function of said detected infrared energy;digitizing said detector signal to produce a series of digital samples indicative of said detector signal at controllable sampling intervals;processing said series of digital samples using a plurality of predetermined algorithms to produce a signal indicative of occupancy of said space;automatically modifying said predetermined algorithms to adjust said processing step as a function of a history of said signal indicative of occupancy; andautomatically energizing and de-energizing an electrical load as a function of said signal indicative of occupancy.