METHOD AND APPARATUS FOR DETERMINING THE POSITION OF A VEHICLE, COMPUTER PROGRAM AND COMPUTER PROGRAM PRODUCT

• US 20090067673A1
• Filed: 09/10/2008
• Published: 03/12/2009
• Est. Priority Date: 09/12/2007
• Status: Active Grant

• Current Assignee: Pepperl + Fuchs GmbH
• Original Assignee: Pepperl + Fuchs GmbH
• Inventors: Hofmann, Hilmar, Kirsch, Martin, Opper, Rudiger
• Granted Patent: US 8,385,594 B2
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: B66C 13/46 Position indicators for suspended loads or for crane elements
• CPC Class Codes: G01D 2205/90 Two-dimensional encoders, i.e. having one or two codes extending in two directions
• CPC Class Codes: G01D 5/2497 Absolute encoders G01D5/2454 takes precedence
• CPC Class Codes: G01D 5/34746 Linear encoders
• CPC Class Codes: G01D 5/34776 Absolute encoders with analogue or digital scales

Abstract

The present invention relates to an apparatus and a method for determining the position of a vehicle moved along a path, markers, particularly code carriers or barcodes being located along the path.. The method is characterized in that the markers are detected with a digital camera placed on the vehicle and that by means of image processing from a position of at least one marker image in the detection or coverage range of the digital camera a position of the vehicle relative to the given marker or the given markers in the main vehicle movement direction along the path and in at least one direction at right angles to the main movement direction is determined. The invention also relates to a computer program and a computer program product.

Claims

1. Method for determining the position of a vehicle moving along a path (12), markers (20), particularly code carriers or barcodes being positioned along the path (12),

characterized in that

the markers (20) are detected with a digital camera (30) placed on the vehicle (10) and

that by means of image processing from a position of at least one marker image (71-74) in the detection range (32) of the digital camera (30) determination takes place of a position of the vehicle (10) relative to the given marker (21, 22, 23) or the given markers (21, 22, 23) in the direction of a main movement direction (x) of the vehicle (10) along path (12) and in at least one direction (y, z) at right angles to the main movement direction (x).

2. Method according to claim 1,

characterized in that

position changes (Ay) of the vehicle (10) at right angles to the main movement direction (x) of the vehicle (10) are determined on the basis of shifts (Δ

) of the marker images (71-74) in the detection area (32) of the digital camera (30).

3. Method according to claim 1 or 2,

characterized in that

distance changes (Δ

z) of the vehicle (10) relative to the path (12) are determined from changes in the size of the marker images (71-74).

4. Method according to one of the claims 1 to 3,

characterized in that

when a system is put into operation for the first time at least one reference run is made, in which relative positions of the vehicle (10) in at least one direction (y, z) at right angles to the main movement direction (x) associated with the relative positions of the vehicle (10) in the main movement direction (x) are recorded and stored.

5. Method according to one of the claims 1 to 4,

characterized in that

error signals are outputted if the values determined for the relative positions of the vehicle (10) in directions (y, z) at right angles to the main movement direction (x) pass beyond predetermined tolerance intervals.

6. Method according to one of the claims 1 to 5,

characterized in that

two-dimensional barcodes (21, 22, 23) are used as markers (20).

7. Method according to one of the claims 1 to 6,

characterized in that

the markers (20) are arranged in several rows along the path (12).

8. Method according to one of the claims 1 to 7,

characterized in that

determination takes place of the weight of a load (60) supplied to the vehicle (10) on the basis of shifts (A) of marker images (71-74) in the detection range (32) of the digital camera (30).

9. Method according to one of the claims 1 to 8,

characterized in that

the vehicle (10) has rollers (16) and that wear to the rollers (16) is determined on the basis of shifts (A) of marker images (71-74) in the detection range (32) of the digital camera (30).

10. Method according to one of the claims 1 to 9,

characterized in that

from the positions relative to individual markers (21, 22, 23) for the vehicle (10) absolute positions of said vehicle (10) relative to the environment are determined on the basis of known positions of said markers (21, 22, 23) with respect to the environment.

11. Apparatus for determining the position of a vehicle movable along a path (12), particularly for performing the method according to one of the claims 1 to 10, characterized by

a digital camera (30) to be placed on the vehicle (10) for detecting markers (20), particularly code carriers or barcodes, positioned along the path (12), and

a computing device (40) set up for determining a position of the vehicle (10) relative to at least one marker (21, 22, 23) in a main movement direction (x) of vehicle (10) along the path (12) and at least one direction (y, z) at right angles to the main movement direction (x) by means of image processing from a position of the image of the given marker (21, 22, 23) or the given markers (21, 22, 23) in a detection area (32) of the digital camera (30).

12. Apparatus according to claim 11,

characterized in that

the vehicle (10) is intended for transporting loads (60) and that the digital camera (30) is coupled to a component of the vehicle (10), which is elastically deformable when the vehicle (10) is subject to a load (60) to be transported.

13. Apparatus according to claim 11 or 12,

characterized in that

digital camera (30) is coupled to a spring (64) located on a base frame or base support (15) of the vehicle (10).

14. Computer program with program code means in order to carry out the computing and evaluation steps of a method according to one of the claims 1 to 10, if the computer program is performed on a computer functionally connected to the digital camera (30) and in particular on the computing device (40) according to claim 11.

15. Computer program product with program code means stored on a computer-readable data carrier, in order to carry out the computing and evaluating steps of a method according to one of the claims 1 to 10, if the computer program is performed on a computer functionally connected to the digital camera (30), particularly on the computing device (40) according to claim 11.