Optical device for measuring the displacement velocity of a first moving element with respect to a second element

• US 7,345,745 B2
• Filed: 06/24/2005
• Issued: 03/18/2008
• Est. Priority Date: 07/06/2004
• Status: Expired due to Fees

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Flament, Bruno, Cattin, Viviane, Fourcault, William, Peltie, Philippe
• Primary Examiner(s): Tarcza; Thomas H.
• Assistant Examiner(s): BRAINARD, TIMOTHY A
• Application Number:
  US11/629,211
• Publication Number:
  US 20070229798A1
• Time in Patent Office: 998 Days
• Field of Search: 356/3.1
• US Class Current: 356/28
• CPC Class Codes: G01P 3/68 using optical means, i.e. using infrared, visible, or ultraviolet light G01P3/80 takes precedence ; by reflection of waves G01S17/58
• CPC Class Codes: G01P 3/806 in devices of the type to be classified in G01P3/68
• CPC Class Codes: G01S 17/48 Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating

Abstract

An optical device for measuring the displacement velocity of a first movable element in relation to a second element which is fixed to one of said elements and comprises two lasers transmitting two incident beams towards the other elements. The device including photosensitive linear arrays for front and rear detection which are substantially perpendicular to each other. Additional front and rear photosensitive linear arrays are disposed at a distance from the photosensitive front and rear linear arrays. A processing circuit is connected to the photosensitive linear arrays and determines the longitudinal and/or transversal displacement velocity of the movable element. The circuit also determines the distance between the device and the other element by means of optical triangulation and corrects the longitudinal and/or transversal displacement velocity value according of the said distance.

Claims

1. An optical measuring device for measuring the displacement velocity of a first moving element with respect to a second element, said first moving element moving in a displacement plane substantially parallel to the second element, the optical measuring device being fixed to one of the two elements and comprising:

means for emitting at least one incident light beam in the direction of the other element,

means for receiving the light scattered by the other element, comprising front and rear detection means arranged substantially perpendicularly to one another, as well as an additional detection means,

processing means, connected to the front and rear detection means and comprising means for determining the longitudinal and/or transverse displacement velocity of the first moving element, said

processing means, connected to the additional detection means, comprising means for determining, by optical triangulation, the distance between the device and the other element, in a plane perpendicular to said displacement plane, and correction means for determining corrected values of the longitudinal and/or transverse displacement velocity according to said distance and to the values supplied by the means for determining the longitudinal and/or transverse displacement velocity of the moving element.

2. Device according to claim 1, wherein the additional detection means comprise front additional detection means arranged at the front of the device, away from a plane defined by the front detection means and an optical axis associated with the front detection means.

3. Device according to claim 2, wherein the means for determining the distance comprise means for determining a front distance, between the front of the device and the other element, from signals supplied by the front additional detection means, the processing means comprising determining means to determine a front optical magnification of the optical receiving means, from the front distance.

4. Device according to claim 1, wherein the additional detection means comprise rear additional detection means arranged at the rear of the device, away from a plane defined by the rear detection means and an optical axis associated with the rear detection means.

5. Device according to claim 4, wherein the means for determining the distance comprise means for determining a rear distance, between the rear of the device and the other element, from signals supplied by the rear additional detection means, the processing means comprising determining means to determine a rear optical magnification of the optical receiving means, from the rear distance.

6. Device according to claim 3, wherein the correction means take into account the optical magnification values determined to correct the velocity values.

7. Device according to claim 1, wherein the detection means of the device are photosensitive arrays.

8. Device according to claim 1, wherein the emitting means of the device comprise at least one laser.

9. Device according to claim 1, comprises focusing means to focus the scattered light on the front, rear and additional detection means.