Method and Apparatus for Noise Control in Ultrasonic Sensors

• US 20140283607A1
• Filed: 03/17/2014
• Published: 09/25/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: The Watt Stopper Incorporated (Legrand SA)
• Original Assignee: The Watt Stopper Incorporated (Legrand SA)
• Inventors: WEIDMAN, Louia, CHEN, Aizhong, FAN, Chenghao
• Granted Patent: US 9,417,347 B2
• Time in Patent Office: Days
• US Class Current: 73/584
• CPC Class Codes: G01N 29/34 Generating the ultrasonic, sonic or infrasonic waves , e.g. electronic circuits specially adapted therefor
• CPC Class Codes: G01S 15/04 Systems determining presence of a target
• CPC Class Codes: G01S 7/52004 Means for monitoring or calibrating short-range imaging G01S7/5205
• CPC Class Codes: G01V 1/001 Acoustic presence detection
• CPC Class Codes: G01V 1/247 Digital recording of seismic data, e.g. in acquisition units or nodes
• CPC Class Codes: G01V 1/3852 to the seabed
• CPC Class Codes: H05B 47/105 in response to determined parameters
• CPC Class Codes: H05B 47/115 by determining the presence or movement of objects or living beings

Abstract

The adjustable voltage regulator under control of a microcontroller applies controlled amplitude voltage in the range of 5 to 9 VDC to the sensor transmitter to adjust the output amplitude of the transmitter. The adjustable amplitude transmitter allows an occupancy sensor to have its total output energy adjusted to reduce environmental noise-induced false triggering and to conform to the area to be covered. Lowering the total ultrasonic energy in the monitored space lowers the sensitivity of the receiver to inappropriate activations. Lowering the input power to the transmitter also lowers the total internal system noise and provides an improved signal to noise ratio in the receiver.

Claims

1. An active ultrasonic occupancy sensor comprising:

an ultrasonic transmitter;

an ultrasonic receiver;

a power supply applying power to an adjustable voltage regulator which applies adjustable power to the ultrasonic transmitter;

a microcontroller controlling the ultrasonic transmitter and the ultrasonic receiver and controlling the output voltage of the adjustable regulator;

means for processing the received ultrasonic signal to generate a first signal representing the ultrasonic voltage envelope;

a peak detector processing the first signal to generate an ultrasonic peak noise signal; and

firmware in the microcontroller for controlling the output voltage of the adjustable regulator according to the ultrasonic peak noise signal.

2. An active ultrasonic occupancy sensor comprising:

an ultrasonic transmitter;

an ultrasonic receiver;

a power supply applying power to an adjustable voltage regulator which applies adjustable power to the ultrasonic transmitter;

a microcontroller controlling the ultrasonic transmitter and the ultrasonic receiver and controlling the output voltage of the adjustable regulator;

interface means for adjusting the sensitivity input of the sensor, wherein the microcontroller controlling the output voltage of the adjustable regulator according to the sensitivity input of the sensor and the ultrasonic peak noise signal.