Low-power triggered data acquisition system and method

• US 8,170,836 B1
• Filed: 01/30/2009
• Issued: 05/01/2012
• Est. Priority Date: 02/04/2008
• Status: Active Grant

• Current Assignee: Invocon Inc.
• Original Assignee: Invocon Inc.
• Inventors: Champaigne, Kevin, Sumners, Jonathan
• Primary Examiner(s): TSAI, CAROL S W
• Application Number:
  US12/362,504
• Time in Patent Office: 1,187 Days
• Field of Search: 702/35, 702/187, 735/83, 736/59, 735/87, 735/94, 345/177, 178/18.04, 367/13, 375/257, 375/219
• US Class Current: 702/187
• CPC Class Codes: G01M 5/0033 by determining damage, crack or wear
• CPC Class Codes: G01M 5/0066 by exciting or detecting vibration or acceleration vibration testing of structures G01M7/00
• CPC Class Codes: G01N 2291/0427 Flexural waves, plate waves, e.g. Lamb waves, tuning fork, cantilever
• CPC Class Codes: G01N 29/045 by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks measuring resonant frequency G01H13/00; measuring strength properties by application of mechanical stress G01N3/00
• CPC Class Codes: G01N 29/14 using acoustic emission techniques echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00
• CPC Class Codes: G01N 29/36 Detecting the response signal , e.g. electronic circuits specially adapted therefor

Abstract

A low-power triggered data acquisition system and method utilizes low-powered circuitry, comparators, and digital logic incorporated into a miniaturized device interfaced with self-generating transducer sensor inputs to detect, identify and assess impact and damage to surfaces and structures wherein, upon the occurrence of a triggering event that produces a signal greater than a set threshold changes the comparator output and causes the system to acquire and store digital data representative of the incoming waveform on at least one triggered channel. The sensors may be disposed in an array to provide triangulation and location of the impact.

Claims

1. A low-power triggered data acquisition system for continuously monitoring detecting, identifying and assessing impact and damage to surfaces, comprising:

a plurality of self-generating transducer sensors that do not require constant excitation voltage or current disposed on the surface for generating an electrical charge output signal responsive to a triggering event;

a plurality of comparator means each having a first input interfaced with a respective said transducer sensor for receiving said electrical charge output signal from the respective said sensor, a second input for receiving a threshold voltage from a voltage source correlated with a respective sensor, and each comparator means having an output;

digital memory means for storing digital data;

digital logic circuitry interfaced with a frequency source functioning as a clock means and with said comparator means output for controlling the operation of the system including latching and reset functions, and transferring data from each said digital converter means to said digital memory means; and

signal conditioning means and analog-to-digital converter means interfaced with said self-generating transducer sensors, said digital logic circuitry, and said first input of each said comparator means for conditioning analog output signals from said sensors prior to being received by each said comparator means;

wherein, the output of said comparator means changes upon receiving an electrical charge output signal from a first one of said sensors that is greater than the threshold voltage correlated with said first one of said sensors received by said comparator means to cause said digital logic circuitry to acquire and store digital data representative of a first triggering event generated by said first one of said sensors in said digital memory means, along with the output from the other said sensors, and said digital logic circuitry latches and resets the system for detecting a subsequent triggering event.

2. The low-power triggered data acquisition system according to claim 1, further comprising:

communication interface means coupled with said digital memory means for transferring digital data stored in said memory means to another device.

3. The low-power triggered data acquisition system according to claim 1, wherein

said analog-to-digital converter means comprises a high-speed, low-latency component that is capable of remaining in a low power state until a digital input causes it to begin sampling analog input and providing digital output data.

4. The low-power triggered data acquisition system according to claim 1, wherein

said self-generating transducer sensors are disposed on the surface in an array to provide triangulation, and said digital logic circuitry is programmed to perform a triangularization routine;

the triggering event is an impact on the surface and the digital data acquired is representative of an acceleration wave that arrives at one or more of said sensors at different times; and

said digital logic circuitry, said clock means and said triangularization routine determine the arrival angle of the acceleration wave to provide data representing relative time of arrival at one or more of said sensors and thereby provide information related to the location of the impact.

5. The low-power triggered data acquisition system according to claim 1, wherein

said frequency source comprises an RC oscillator.

6. The low-power triggered data acquisition system according to claim 1, wherein

said self-generating transducer sensors are selected from the group consisting of impact sensors, piezoelectric-based transducers, accelerometers, acoustic emission (AE) sensors, PZT elements, pressure sensors, strain gauges, photo-transistors, photo-diodes, photo-cells, radiation detectors, and microphones.