Systems and methods of reducing a component of a signal caused by vibration

• US 7,952,347 B2
• Filed: 07/29/2010
• Issued: 05/31/2011
• Est. Priority Date: 07/19/2007
• Status: Active Grant

• Current Assignee: Carnes Company, Inc.
• Original Assignee: Carnes Company, Inc.
• Inventors: Simon, Joseph S.
• Primary Examiner(s): LeDynh; Bot L
• Application Number:
  US12/846,127
• Publication Number:
  US 20100312523A1
• Time in Patent Office: 306 Days
• Field of Search: 324/225, 324/228, 324/234, 324/236, 324/239, 736/62
• US Class Current: 324/228
• CPC Class Codes: G01V 3/104 using several coupled or uncoupled coils G01V3/101 takes precedence

Abstract

A vibration detection circuit. The circuit includes an accelerometer, a combining filter, an amplifier, and an analog to digital converter. The accelerometer generates one or more signals indicative of movement along an axis. The combining filter filters a component of the one or more signals not associated with movement and combines the components of the one or more signals indicative of movement to create a combined signal. The amplifier amplifies the combined signal and creates an amplified signal. The analog to digital converter converts the amplified signal into a digital value.

Claims

1. A vibration detection circuit, comprising:

an accelerometer configured to generate one or more signals, each signal indicative of movement along an axis;

a combining filter configured to filter a component of the one or more signals not associated with movement and to combine the components of the one or more signals indicative of movement to create a combined signal;

an amplifier configured to amplify the combined signal and create an amplified signal; and

an analog to digital converter configured to convert the amplified signal into a digital value.

2. The vibration detection circuit of claim 1, wherein the one or more signals include a first signal indicative of movement on a first axis and a second signal indicative of movement on a second axis orthogonal to the first axis.

3. The vibration detection circuit of claim 2, wherein the one or more signals include a third signal indicative of movement on a third axis, the third axis orthogonal to the first and second axes.

4. The vibration detection circuit of claim 1, wherein the accelerometer is mounted to a passageway of a metal detector, the accelerometer detecting vibration of the passageway.

5. The vibration detection circuit of claim 1, wherein the digital value is used to modify a detection signal of a metal detector, the modified detection signal having a component related to movement of the metal detector substantially removed.