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

• US 8,570,032 B2
• Filed: 05/11/2011
• Issued: 10/29/2013
• 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:
  US13/105,280
• Publication Number:
  US 20110209519A1
• Time in Patent Office: 902 Days
• Field of Search: 324/228
• 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 method of reducing a vibration component of a detection signal in a metal detector, the method comprising:

detecting movement of the metal detector on a first axis;

generating a first signal indicative of the movement on the first axis; and

modifying a detection signal based at least on the first signal.

2. The method of claim 1, further comprising

detecting movement of the metal detector on a second axis orthogonal to the first axis;

generating a second signal indicative of the movement on the second axis; and

combining the first and second signals to create a combined signal;

wherein the modifying of the detection signal is based on the combined signal.

3. The method of claim 2, further comprising

detecting movement of the metal detector on a third axis orthogonal to the first and second axes;

generating a third signal indicative of the movement on the third axis; and

combining the first, second, and third signals to create the combined signal.

4. The method of claim 3, further comprising filtering the first, second, and third signals before combining.

5. The method of claim 1, further comprising amplifying the first signal, to create an amplified signal, before modifying the detection signal.

6. The method of claim 5, further comprising converting the amplified signal to a digital value and providing the digital value to a controller.

7. The method of claim 1, wherein the detection signal is modified by scaling and/or a subtraction.

8. A method of reducing a vibration component of a detection signal in a metal detector, the method comprising:

detecting movement of the metal detector on a first axis;

generating a first signal indicative of the movement on the first axis; and

detecting movement of the metal detector on a second axis orthogonal to the first axis;

generating a second signal indicative of the movement on the second axis; and

combining the first and second signals to create a combined signal;

modifying a detection signal based on the combined signal using scaling and/or subtraction.

9. The method of claim 8, further comprising

detecting movement of the metal detector on a third axis orthogonal to the first and second axes;

generating a third signal indicative of the movement on the third axis; and

combining the first, second, and third signals to create the combined signal.

10. The method of claim 9, further comprising filtering the first, second, and third signals before combining.

11. The method of claim 8, further comprising amplifying the first signal, to create an amplified signal, before modifying the detection signal.

12. The method of claim 11, further comprising converting the amplified signal to a digital value and providing the digital value to a controller.