WO2002077569A1

WO2002077569A1 - Contact wire inspection with separate position determination

Info

Publication number: WO2002077569A1
Application number: PCT/DE2002/000840
Authority: WO
Inventors: Martin Dambacher; Nikolaos Dimopoulos; Heinrich HÖFLER; Michael Seib
Original assignee: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
Priority date: 2001-03-24
Filing date: 2002-03-08
Publication date: 2002-10-03
Also published as: EP1373826A1; DE10114575B4; DE10114575A1

Abstract

The invention relates to a device for determining the residual thickness of at least one circular contact wire (4) comprising a position determination unit (2) for determining the position of the or each contact wire (4), said unit being coupled to a residual-thickness determination unit (7). Tracking means of the residual-thickness determination unit (7) are impinged by output signals corresponding to the position of the or each contact wire (4). The tracking means allow an image recording field (8) of the residual-thickness determination unit (7) to track the current position of the or each contact wire (4), in such a way that the width of a worn surface, caused by erosion on the underside of the or each contact wire (4) and the residual thickness resulting therefrom can be determined, the geometry of each contact wire being known.

Description

TRACTIVE WIRE INSPECTION WITH SPECIAL POSITIONING

5 The invention relates to a device for determining the remaining thickness of at least one round contact wire according to the preamble of independent claim 1.

Such a device is known from the final report "Automatic optical monitoring of the contact wire on railways", final report on the BMBF joint project PROFIL, funding code 16SV703 / 0, dated October 10, 1999. The previously known device has a lighting unit with which To determine the cross-sectional profile of a contact wire, image recording means and image processing means of a residual thickness determination unit are provided, with which light sections from each side of the respective contact wire can be recorded and processed to determine the remaining thickness In order to counteract the migration of the respective contact wire from the field of view of the image recording means, actuating signals can be generated by the image processing means, with which the field of view is continuously controlled to 5 den, controlled by tracking means respective contact wire remains directed. A disadvantage of this previously known device, however, is that, due to the lack of initial information about the position of the contact wire at a standstill, a search process must be carried out in order to align the field of view of the image recording means with the contact wire to be detected. Furthermore, there are considerable problems when a further contact wire runs in, for example in the area of switches. Finally, the accuracy with changing altitude of the contact wire is limited due to the lack of correction options. 5 From the article "Contact wire position measurement on high-speed lines" by H. Höfler, N. Dimopoulos and B. Metzger, published in eb 3/98 (electric railways 96 (1998) 3), pages 61 to 64 is a device for determining both the altitude and Also known from the lateral position of up to four contact wires, this device has a laser-shaped, intensity-modifiable scanning radiation source with which a directed scanning beam can be emitted via a pivoting mirror in a plane oriented at an angle to the longitudinal direction of the or each contact wire The position of the mirror determines the direction of the scanning beam and the distance to the respective contact wire by means of a transit time measurement, so that the combination of the data obtained in this way enables the height and lateral position of the respective contact wire to be determined without contact even at high speeds.

The invention has for its object to provide a device of the type mentioned, with which a determination of the remaining thickness of at least one round contact wire can be carried out with high accuracy both at a standstill and at high speeds.

This object is achieved according to the invention with the characterizing features of independent claim 1.

The fact that the device according to the invention has a position determination unit coupled to the tracking means, with which the position of the or each contact wire can be determined and the field of view of the image recording means can be kept aligned with the respective current position of the respective contact wire with corresponding correction signals on the one hand, relieving the time-critical image data processing from the task of aligning the field of view of the image recording means on the each contact wire and on the other hand trapping the contact wire even when it is at a standstill. By keeping the imaging ratios constant and recording the width of the grinding mirror, finally, to determine the remaining thickness of the contact wire with knowledge of the cross-section of a wear-free contact wire, it is relatively quick to check the condition of the contact wires with high precision, both at low and at high speeds created.

Appropriate embodiments of the invention are the subject of the dependent claims.

Further expedient refinements and advantages of the invention are the subject of the following description of exemplary embodiments with reference to the figures of the drawing.

Show it:

1 is a perspective view of a position determination unit, a lighting unit and a residual thickness determination unit of an exemplary embodiment of a device according to the invention, which are mounted on a wagon roof of a railway wagon and are set up to determine the remaining thickness of an individual contact wire,

2 schematically shows an exemplary structure of a position determination unit and a residual thickness determination unit of a device according to the invention,

3 schematically shows a further exemplary construction of a residual thickness determination unit for a device according to the invention, 4 shows a perspective view of a position determination unit, a lighting unit and a residual thickness determination unit of a further exemplary embodiment of a device according to the invention, which are mounted on a wagon roof of a railroad wagon and are set up to determine the remaining thickness of two adjacent contact wires,

5 shows a schematic view of the effect of tracking means of the position determination unit,

6 shows a block diagram of the structure of image recording means and image processing means of the residual thickness determination unit and

7 shows a schematic representation in section of a partially worn contact wire with an associated one, generated by image recording means and image processing means of the residual thickness determination unit

Image.

1 shows a perspective view of a wagon roof 1 of a railroad wagon, not shown in detail in FIG. 1, which is set up to check travel routes. A position determination unit 2 of a device according to the invention is attached to the car roof 1, at least with its optical components, which are explained in more detail below. With the position determination unit 2, a directed scanning beam 3 can be pivoted in a manner explained in more detail below as scanning radiation in a plane which is oriented at an angle, preferably at right angles to the longitudinal direction, of a contact wire 4 running above the car roof 1. The driving area, which is designed with a round cross-section in the downward-facing area when properly arranged wire 4 is used in particular for supplying railway railcars with electrical energy, it being subject to a certain amount of wear on the underside due to the action of the pressing force of the pantographs used for this purpose.

Furthermore, an illumination unit 5 of the device according to the invention is mounted on the car roof 1, with which illumination radiation can be emitted in an elongated illumination field 6, preferably oriented at right angles to the longitudinal direction of the contact wire 4, in the direction of the contact wire 4. The position of the illumination field 6 is preferably stationary. The extension of the illumination field 6 transversely to the contact wire 4 is set up in such a way that even extreme lateral edge positions of the contact wire 4 are still within the illumination field 6. This ensures constant illumination of the area where the contact wire 4 is located with illuminating radiation. The illumination unit 5 has, for example, an elongated, radiation-intensive fluorescent lamp, the illumination radiation of which is bundled via mirror optics and a cylindrical lens optics to form the illumination field 6, which is preferably relatively narrow in the transverse direction.

Furthermore, the device according to the invention has a residual thickness determination unit 7 which, at least with its optical components explained in more detail below, is also attached to the car roof 1. With the residual thickness determination unit 7, portions of the illuminating radiation which are reflected back from the illuminating field 6 in an image recording visual field 8 can be received and processed in a manner explained in more detail below.

FIG. 2 schematically shows an exemplary structure of a position determination unit 2 and a residual thickness determination unit 7 of a device according to the invention. The position determination unit 2 has a modulator 9, which with a radiation-intensive scanning radiation source 10, for example as a laser emitting in the near infrared spectral range. The scanning beam 3, which is periodically, for example sinusoidal or rectangular, intensity-modulated can be emitted with the scanning radiation source 10 controlled by the modulator 9. The scanning beam 3 acts on a scanning reflector 11, which is pivotally mounted, driven by a scanning reflector submodule 12. As a result, as explained in connection with FIG. 1, the scanning beam 3 emerging from the position determination unit 2 can be pivoted accordingly. The scanning reflector submodule 12 has a rotary encoder with which an angle signal corresponding to the rotational position of the scanning reflector 11 can be output.

The position determination unit 2 according to FIG. 2 furthermore has a scanning radiation detection module 13, with which, when the scanning beam 3 strikes the contact wire 4 shown in FIG. 1, a reflected portion 14 reflected in the direction of the position determination unit 2 can be detected as a portion of the scanning beam 3 with an intensity detector , The output signal of the scanning radiation detection module 13 can be fed to a propagation time determination module 15. The runtime determination module 15 is also fed by an output signal of the modulator 9 which corresponds to the phase position of the transmitted scanning beam 3. With the transit time determination module 15, the entire transit time of the scanning beam 3 between the position determination unit 2 and the contact wire 4 can be determined from the phase difference between the output signal of the modulator 9 and the output signal of the scanning radiation detection module 13 and output as a transit time signal.

The residual thickness determination unit 7 according to FIG. 2 has a first deflection reflector 16 and a second deflection reflector

17 and a third deflection reflector 18, via which from the contact wire 4 in the direction of the residual thickness determination unit 7 discarded illuminating radiation portions 19 of the illuminating radiation can be fed to an image recording reflector 20 by tracking means 21 via a folded beam path. With the image pick-up reflector 20, the illuminating radiation components 19 can be deflected out of the plane in which the deflecting reflectors 16, 17, 18 lie. The image recording reflector 20 is designed to be pivotable in a controlled manner via an image recording reflector actuating module 22 of the tracking means 21.

In the embodiment according to FIG. 2, image recording means 23 of the residual thickness determination unit 7 have a lens 25 which can be adjusted in the focal length and thus in the magnification by means of a focal length adjusting module 24 and which, due to its design, is also referred to as a zoom lens. A two-dimensional area detector 26 of the image recording means 23 with a number of flatly arranged detector elements sensitive to the illuminating radiation components 19 is arranged downstream of the objective 25 and connected to image processing means 27.

The image pick-up reflector control module 22 is connected to the scanning reflector sub-module 12 and can be acted upon by the angle signal generated by the rotary encoder of the scanning reflector control module 12. Furthermore, the focal length adjustment module 24 is connected to the runtime determination module 15 for feeding in the distance signal. The scanning reflector control module 12, the propagation time determination module 15, the image pickup reflector control module 22 and the focal length control module 24 cooperate in such a way that by tracking the image pickup reflector 20 and the focal length of the lens 25 the image of the contact wire 4 is of the same size at all times due to correction of the imaging conditions lies on the surface detector 26.

3 schematically shows a further exemplary construction of a residual thickness determination unit 7 for a device according to the invention, wherein for the residual thickness determination 2 and components corresponding to the residual thickness determination unit 7 shown in FIG. 3 are provided with the same reference numerals and are not explained in more detail below. In the residual thickness determination unit 7, the third deflection reflector 18 is designed to be pivotable, controlled by a deflection reflector control module 28. The image recording means 23 of the residual thickness determination unit 7 according to FIG. 3 are equipped with a one-dimensional line detector 29 which has a number of detector elements arranged in a row and sensitive to the illuminating radiation components 19. When the third deflecting reflector 18 is pivoted, the one-dimensional image of the contact wire 4 can thus be displaced via the line detector 29, so that even when the device according to the invention is moved very slowly or when the third deflecting reflector 18 is pivoted into successive positions by reading out the line detector 29 a two-dimensional image of the contact wire 4 can be generated in each position and subsequent areal assignment of the one-dimensional images.

FIG. 4 shows a perspective view of a position determination unit 2, a lighting unit 5 and a residual thickness determination unit 7 of a further exemplary embodiment of a device according to the invention, which is attached to a wagon roof 1 of a railway wagon not shown in detail in FIG. 4 and for determining the remaining thickness of two adjacent contact wires 4 are set up with one of the types explained with reference to FIG. 1. The position determination unit 2 is configured essentially like the position determination unit 2 explained in the first exemplary embodiment according to FIGS. 1 to 3 and is set up to detect reflex portions 14 of the scanning beam 3 which are reflected by the two contact wires 4 and to detect pairs discriminated from each other and corresponding pairs assigned to each contact wire 4 generate angle signals and runtime signals. Thieves- Illumination unit 5 is set up to generate a stationary illumination field 6, within which the two contact wires 4 are located even in extreme peripheral positions. Except for common image processing means 27, the residual thickness determination unit 7 according to the embodiment according to FIG. 4 essentially comprises a corresponding doubling of the construction of the residual thickness determination unit 7 according to the first exemplary embodiment explained with reference to FIGS. 2 and 3, in order to record 4 separate images for each contact wire ,

FIG. 5 shows a schematic view of the effect of tracking means 21 of the position determination units 7 explained above. FIG. 5 illustrates that, by pivoting the image recording reflector 20, the contact wire 4 migrates sideways and by changing the focal length of the lens 25 by adjusting the focal length and thus the mapping scale to constant mapping ratios, emigration in height can be compensated so that, for example, a constant image of the respective contact wire 4 constantly falls on the area detector 26.

6 shows in a block diagram the structure of the image recording means 23 and the image processing means 27 of the residual thickness determination unit 7. As already explained in connection with FIGS. 3, 4 and 5, the illuminating radiation portions 19 act on the zoom lens Objective 25, which, as shown in FIG. 6, is upstream of the area detector 26, for example. Depending on the type of the area detector 26, it is expedient, given the amount of data to be generated, that only a number of evenly spaced lines at an angle to the wear of a contact wire 4 by current collectors takes place quasi continuously, at least without sharp steps Read 4 rows of detector elements aligned in the longitudinal direction of the contact wire.

The output signal of the area detector 26 can be fed to a noise filter 30, which is preferably designed as a so-called field programmable gate array (FPGA), with which noise components can be eliminated on the basis of a noise suppression algorithm programmed into the noise filter 30 in a hardware-related manner in accordance with the functioning of FPGAs. The output signal of the noise filter 30 can be fed to an edge filter 31, which is also preferably designed as an FPGA. The edge filter 31 can be used to filter out edges contained in the image recorded by the area detector 26, ie lines of pixels with a uniform characteristic, on the basis of a filter function that is also programmed in the hardware.

The output signal of the edge filter 31 can be stored in a fast image memory 32, in which the pixels corresponding to the edge profiles can be stored depending on the corresponding position on the contact wire 4. The image memory 32 can be accessed with extremely short read and write times. To generate the position data, a position transmitter 33 is provided, which is coupled, for example, to a wheel axle of the railroad car equipped with the device according to the invention. The image memory 32 is connected to a computing module 34, for example designed as a single-user computer, to which an input module 35, for example a keyboard, an mass data memory 36, for example a so-called hard disk, and an output module 37 designed as a screen and / or printer are connected as peripheral devices.

In the computing module 34, the image read out from the image memory 32, which acts as a buffer, is double filtered image data, as explained in more detail below in connection with FIG. 7, can be determined with reference to the distance from edges characteristic of the degree of wear of the respective contact wire 4 and, based on the knowledge of the geometric cross-sectional relationships, the remaining thickness of the examined contact wire for a correspondingly designed, wear-free contact wire 4 4 can be determined depending on the position.

7 shows a schematic illustration in section of a contact wire 4 which is partially worn out by the action of the current collectors during driving operation, with an associated image generated by the image recording means 23 and image processing means 27 of the residual thickness determination unit 7 and reproduced via the output module 37. The image generally contains an outer first edge 38 and an outer second edge 39 which, when the contact wire 4 is arranged as intended in the lower region due to the rounded cross section, in each case the outermost edge of a curved first flank 40 and a second flank 41 of the contact wire 4 correspond.

The image also contains an inner third edge 42 and an inner fourth edge 43, each of which is assigned to the inner edge of the first flank 40 or the second flank 41. The inner third edge 42 and the inner fourth edge 43 delimit the area of the contact wire 4, which, when the contact wire 4 is arranged as intended, extends between the first contact edge 40 and the second contact edge 41 at the bottom, is ground flat due to wear and is referred to as grinding mirror 44.

In unfavorable cases, such as in extreme lateral edge positions of the respective contact wire 4, one of them may be outer edges 38, 39 for the image recording means 23 covered and therefore not included in the image. In these cases, however, the width of the grinding mirror 44 can still be determined by recognizing the inner edges 42, 43 as limitations of the grinding mirror 44.

With knowledge of the geometric cross-sectional relationships in a correspondingly designed, not worn contact wire 4, the remaining known thickness of the contact wire 4 and the degree of wear can be calculated from the now known position-dependent width of the grinding mirror 24. Furthermore, if the edge filter 31 is designed appropriately and if the image data provided by the area detector 26 or the line detector 29 is substantially fully utilized, singular events such as burn-in points can also be recognized automatically by means of corresponding image processing algorithms, which under certain circumstances also indicate an acute need for replacement.

Claims

1.Device for determining the remaining thickness of at least one round contact wire (4) with an illumination unit with which the or each contact wire (4) can be exposed to illuminating radiation, and with a residual thickness determination unit having image recording means and image processing means, with which a portion of the of the or each contact wire (4) throwing back illumination radiation, the remaining thickness of the respective contact wire (4) can be determined, tracking means are available with which the or each contact wire (4) can be kept in the field of view of the image recording means, characterized in that a position determining unit (2 ) is present, with which the position of the or each contact wire (4) can be determined, that the tracking means (21) are coupled to the position determination unit (2), the mapping conditions being constantly stable with the tracking means (21), and that the image capturing means (23) and the image processing means (27) for capturing of the respective grinding mirror (44) of a contact wire (4), the remaining thickness of the respective contact wire (4) being determinable by knowing the cross section of a wear - free contact wire (4) across the width of the grinding mirror (44).

2. Device according to claim 1, characterized in that with the lighting unit (5) an elongated, angular to the longitudinal direction of the or each contact wire

(4) aligned lighting field (6) can be generated, the extension of the lighting field (6) transverse to the longitudinal direction of the respective contact wire (4) at least as large as the largest possible to be expected Distance of lateral edge positions of the or each contact wire (4).

3. Device according to claim 1 or claim 2, characterized in that the tracking means (21) have a lens (25) with a focal length adjustment module (24) adjustable focal length.

4. The device as claimed in claim 3, characterized in that the tracking means (21) have a pivotable image pick-up reflector (20) which is driven by an image pick-up reflector actuating module (22) and acts at an angle to the longitudinal direction of the or each contact wire (4), and has reflected lighting radiation components ( 19) from a laterally the longitudinal direction of the or each

Contact wire (4) extending angular range the lens (25) can be fed.

5. Apparatus according to claim 3 or claim 4, characterized in that the position determination unit (2) has a modulator (9) with which a scanning radiation source (10) for emitting intensity-modulated scanning radiation (3) can be controlled, a scanning radiation detection module (13) , with the reflected parts (14) of scanning radiation (3) can be detected, and one with the

Has modulator (9) and the scanning radiation detection module (13) coupled transit time determination module (15), with which the distance to the or each contact wire from the phase difference between the transmitted scanning radiation (3) and the returned portion (14) of the scanning radiation (3) (4) can be determined.

6. The device according to claim 5, characterized in that the position determination unit (2) has a pivotable scanning reflector (11) with which the scanning Radiation (3) is pivotable over an angular range oriented at an angle to the longitudinal direction of the or each contact wire (4).

7. The device according to claim 6, characterized in that the position determination unit (2) has a rotary encoder with which an angle signal corresponding to the angular position of the scanning reflector (11) can be generated, the angle signal to the image pick-up reflector adjusting module (22) for tracking the image pick-up reflector ( 20) can be fed.

8. The device according to claim 7, characterized in that a distance signal corresponding to the distance of the or each contact wire (4) from the transit time determination module (15) to the focal length adjusting module (24) for tracking the focal length of the lens (25) can be fed.

9. The device according to claim 8, characterized in that the image recording means (23) have a two-dimensional area detector (26) with a number of detector elements arranged in one area.

10. The device according to claim 9, characterized in that the image processing means (27) are set up so that a selection of rows of detector elements arranged in a row can be processed.

11. The device according to claim 8, characterized in that the image recording means (23) have a one-dimensional line detector (29) with detector elements arranged in a row.

12. The apparatus according to claim 11, characterized in that the tracking means (21) have a pivotable deflection reflector (18) with which the field of view of the line detector (29) in the longitudinal direction of the or each contact wire (4) is displaceable.

13. The apparatus according to claim 12, characterized in that the deflecting reflector (18) is periodically pivotable.

14. Device according to one of claims 1 to 13, characterized in that the image processing means (27) via application-programmable filters, in particular a noise filter (30) for suppressing noise components and an edge filter (31) for recognizing lines of uniform characteristics, feature.