Method and apparatus for determining linear and angular velocity of a moving body

• US 6,559,632 B1
• Filed: 04/11/2000
• Issued: 05/06/2003
• Est. Priority Date: 04/11/2000
• Status: Expired due to Term

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Javor, Edward R., Anderson, Theodore R.
• Primary Examiner(s): Lefkowitz, Edward
• Assistant Examiner(s): Aurora, Reena
• Application Number:
  US09/548,387
• Time in Patent Office: 1,120 Days
• Field of Search: 324/160-179, 324/207.12, 324/225
• US Class Current: 324/174
• CPC Class Codes: G01P 3/4815 using a pulse wire sensor, e.g. Wiegand wire

Abstract

An apparatus and method for determining linear and angular velocity of a moving body. A magnet is attached or fixed to the body, the velocity of which is to be determined. The apparatus comprises a sensor comprising a core of magnetic material and a coil wound about the core. The movement of the body and magnet relative to the core effects a time-varying magnetic field between the magnet and the core thereby producing Barkhausen effect time-varying voltage signals in the coil. The apparatus further comprises a system for detecting and processing the time-varying voltage signals so as to effect a transformation of the signals into data defining the velocity of the moving body.

Claims

1. An apparatus for determining linear and angular velocity of a moving body having a magnet attached thereto comprising:

a core of magnetic material;

a coil wound about the core, the movement of the body and magnet relative to the core effecting a time-varying magnetic field between the magnet and the core thereby producing Barkhausen effect time varying voltage signals in the coil;

a filter for filtering extraneous noise signals from the Barkhausen effect time-varying voltage signals;

an amplifier for amplifying the filtered signals; and

an analog-to-digital converter for converting the amplified, filtered signals into digital signals;

a processor circuit configured to transform the digital signals into data that defines the velocity of the moving body;

a display for displaying the data;

correction circuitry for producing an error signal that represents the difference between the velocity of the moving-body as defined by the data and a predetermined velocity; and

control circuitry for adjusting or maintaining the velocity of the moving boy in accordance with the error signal.

2. The apparatus according to claim 1 wherein the filter comprises a passive filter.

3. The apparatus according to claim 1 wherein the filter comprises a digital signal processing filter.

4. The apparatus according to claim 1 wherein the magnetic material from which the core is fabricated is ferro-magnetic material.

5. The apparatus according to claim 1 wherein the magnetic material from which the core is fabricated is silicon-steel.

6. A method for determining a velocity of a moving body comprising the acts of:

attaching a magnet to a body, the velocity of which is to be determined;

providing a core of magnetic material having a coil wound thereabout, the movement of the body and magnet relative to the core effecting a time-varying magnetic field between the magnet and the core thereby producing Barkhausen effect time-varying voltage signals in the coil;

filtering extraneous noise signals from the Barkhausen effect time-varying voltage signals;

amplifying the filtered Barkhausen effect time-varying voltage signals;

converting the amplified signals into digital signals;

processing the digital signals to effect a transformation of the digital signals into data defining the velocity of the moving body;

displaying the data;

producing an error signal that represents the difference between the velocity of the moving body as defined by the data and a predetermined velocity; and

adjusting or maintaining the velocity of the moving body in accordance with the error signal.