The Department of Energy’s Savannah River National Laboratory (SRNL) developed the Smart Latch door latching sensor system to indicate whether or not a door is fully closed. The system, which attaches to a standard door, compares the audible signature of a door properly latching to every future instance of the door closing.
The system, developed by Bob Eakle, principal engineer for SRNL, uses a die-mounted VR Stamp speech recognition chip from Sensory Inc. to register the acoustic signature and a small transducer/microphone to pick up the sound. The housing, which according to Eakle is as small as a wrist watch, is constructed of polycarbonate material. When not in use, the Smart Latch “goes to sleep” to avoid draining its battery, and won’t “wake up” until initiated by the sound of the door.
The voice recognition chip is speaker dependent, which means it will ignore sounds that aren’t within the range of the acoustic signature. The chip was programmed with C. The Smart Latch is not available commercially yet, but the SRNL has made the license available through its technology transfer.