FR2769976A1 - SYSTEM FOR MEASURING RAILS, IN PARTICULAR TRACK RAILS FOR CRANES, SHELVING SERVICE DEVICES, TRACK WHEEL BLOCKS - Google Patents

Abstract

- The present invention relates to a system for measuring rails, comprising a transmitting unit which comprises a laser, and a receiving unit which can be driven displaceable in the longitudinal direction of the rail and having at least one photoreceptor facing the laser beam, for determine the position of the laser beam on a vertical measurement surface. - According to the invention, the photoreceptor (6) has a rectangular matrix having a plurality of pixels, the output signals of which are supplied to operating electronics, by means of which the determination of the point of incidence of the laser beam is carried out (4) on the measurement surface (5), by exploiting the pixel output signals, and a distance sensor is provided to detect a change in distance between the transmitting unit (2) and the receiving unit (3).

Description

The invention relates to a system for measuring rails, in particular

  base of running rails for cranes, shelving units, rolling wheel blocks, comprising an emission unit, arranged on the rail, which comprises a laser having at least one laser beam extending in the longitudinal direction of the rail, and a drivable receiving unit which, on the same rail, is movable in the longitudinal direction of the rail and has at least one photoreceptor

  next to the laser beam, which generates an electrical output signal, pro-

  voiced by the incident laser beam, with reference to which the local position of the laser beam can be determined on a vertical measurement surface,

  oriented transversely to the longitudinal direction of the rail.

  From document DD-212 931, a layout arrangement is known.

  safe for monitoring tracks fitted with two rails, which comprises a transmitting unit arranged on the track with a laser alignment device. In this case, the laser beam is oriented so that it serves as a spatially fixed measuring axis for the track rail. The layout of

  measuring device consists of a measuring carriage with displacement drive

  ment, which has two rolling rollers arranged horizontally, as well as, each time, two lateral guide rollers on the sides

  right and left. To detect the position of the relative measuring carriage

  ment to the measurement axis, there is a photoelectric sensor facing

  of the laser beam, which is produced as a photoelectric diode with four

  drants. The electrical signal generated by the incidence of the laser beam, the

  photoelectric diode is brought, each time, to an electronic of ex-

  operation which controls a vertical orientation device, as well as a

  horizontal rotation mechanism for moving or turning the diode

  toelectric. In addition, the order is made so that the four

  quadrants of the photoelectric diode, relative to the laser beam, take

  the same position every time. Due to the high sensitivity

  of the photoelectric diode, in such a measurement arrangement, the detection

  position is limited only by the mechanical precision of the adjustment. The disadvantage of this known measurement arrangement consists in the mechanical orientation of the photoelectric diode, since this determines the accuracy of the detection of the position of the rail, that is to say in

  especially the position modification of the rail running surface.

  In addition, the significant measurement times, due to the mechanical repositioning of the photoelectric diode in the measurement plane (directions

  X and Z) are a drawback.

  The object of the invention is to provide a system for measuring rails, which, for high scanning accuracy, can scan individual positions on the rail to determine the change in position of the running surface of the rail relative to the laser beam, without that, for

  that, a displacement of the photoelectric sensor is necessary.

  For this purpose, the system for measuring rails, of the type described below

  above, is remarkable, according to the invention, in that the photoreceptor has a rectangular matrix having a plurality of pixels (optical sensor elements) arranged directly next to each other, including

  electrical output signals are fed to operating electronics

  tation, by means of which the point of incidence of the spatially stabilized laser beam in position on the measurement surface is determined, only by electronic means, by using the pixel output signals, and in that there is provided distance sensor to detect

  a change in the distance between the transmitting unit and the receiving unit

  tion. In this way, it is possible, for each point, relative to the length of the rail, to determine the change in position of the surface.

  of rolling relative to the fixed laser beam in space. A realization

  tion of the photoreceptor as a rectangular matrix makes it possible to measure, in a two-dimensional way, the intensity distribution of the laser beam, which allows an exact determination of the point of incidence of the main direction of radiation or of the axis of the laser beam on the predefined measurement area. Advantageously, the measurement surface should no longer

  otherwise be moved. The reference point adjustment is not necessary.

  stop only once, i.e. the duration of the measures is shortened

  and, in addition, the accuracy of the measurement is increased.

  It is further proposed that the photoreceptor be a CCD camera ("charge coupling or transfer device"), in front of which is arranged a diffuser, transparent to light, as a measurement surface, which is represented optically on the matrix of the CCD camera. That

  provides a very simple system to mount for measuring rails.

  A more precise determination of the point of incidence of the ray

  laser on the measurement surface is obtained by a so-called sub-resolution

  pixels and, in fact, in that the point of incidence of the laser beam on the diffuser can be determined by adapting the measured position of the sub-pixels of the image of the beam of the diffuser on the matrix. For that,

  each image line and each image column is first of all separate

  dually evaluated in a quadratic zone around the image of the radius and, then, we average the results. As a result, the exact position (position of the sub-pixels) of the ray in the image of the camera is obtained. The difference from the (recorded) starting position (reference point) is therefore a measure of the difference in

  ideal line measuring cart.

  Suitably, the adaptation is carried out by means of a

calculation program.

  The invention also proposes that the operating electronics include

  carries a microprocessor, which guarantees, at low cost, complicated ordering and calculation processes.

  To detect the position of the running surface of the rail in a

  Lesson dependent on the distance, it is proposed, according to the invention, that the distance sensor has a friction wheel rolling on the surface of

rail rolling.

  High distance accuracy is achieved in that the friction wheel is connected to an incremental sensor to detect the bearing length. To check that the measurement is carried out correctly, the movement state of the receiving unit can be detected by means of

friction wheel.

  Advantageously, the reception unit is produced remotely.

  controllable, so that rails that are difficult to access can also be measured in poor visibility conditions or in inappropriate environmental conditions (harmful gases, vapors,

etc ...).

  The laser beam is stabilized in position, before-

  carefully, by means of an electronic level, the fact that, thanks to this-

  stability in an elevated position can be achieved at a relative cost-

mentally weak.

  Suitably, positional stability corresponds to a deviation

  +/- 1 mm for a rail length of 100 m.

  Exact scanning of the measurement positions is possible when, for a rail cross-section made up of core and wing parts, at least two guide rollers spaced apart in the longitudinal direction of the rail, mounted vertically in rotation, and applied under the action of a force to guide the receiving unit are provided on the

  two side surfaces of the rail, as well as at least two rollers

  horizontally mounted in rotation, rolling on the road surface

  ment of the rail, and spaced apart in the longitudinal direction of the rail, having an axis of rotation oriented perpendicular to the longitudinal direction of the rail, of which at least one is driven for driving the receiving unit. The system also makes it possible to measure heavily worn rails, when the vertical height of the guide rollers is, at each

times, individually adjustable.

  The displacement properties are particularly good when

  that, in the longitudinal direction of the rail, the front rolling roller

  is, in each case, arranged behind the front guide rollers.

  The movement stability is improved when the distance from the axes of the rolling roller and the directly adjacent guide roller

  is between simple and triple the diameter of the guide rollers.

  The accuracy of the movement of the receiving unit can be

  improved in that, each time on one side of the rail, the guide rollers

  have a fixed axis of rotation and, on the other side of the rail, fits

  bend under the action of a force on the lateral surface.

  Appropriately, the support, under the action of a force, of the rollers

  guidance is effected by an elastic force.

  In order that the guide rollers can better adapt to inclined rails, the guide rollers are mounted in bearings with

articulated balls.

  To be able to pass over expansion joints and broken rails,

  the guide rollers are arranged in pairs each time on a support

  common longitudinal port, extending in the longitudinal direction of the rail, which is arranged on the receiving unit. At the same time, the forces

  horizontal acting during acceleration and braking are thus

  ties on more points of support, which allows a more stable guidance.

  A better stability compared to transverse inclinations is obtained by a support at two points on the surface of the rail, in that, in the rolling surfaces of the rolling rollers, it is formed, at

center, a radial groove.

  To protect the receiving unit, it is proposed, according to the invention

  tion, to provide it with a security system.

  Defective rails or sections of rails, which can cause the receiving unit to fall, are in particular detected by the safety system present, to detect the distance from a point of

  reference of the receiving unit to the rail, at least one distance sensor.

  To measure at least two rails lying in a plane, it is proposed, according to the invention, that the laser beam is divided into two horizontal partial laser rays, extending perpendicular to each other,

  and, in truth, to determine the difference in height of the two relative rails

  tively to a horizontal line lying in a vertical plane. Thanks to this, it is in particular possible to measure exactly the parallelism

  of the two rails relative to each other in space at a low cost.

  Suitably, the partial laser beam extending transversely

  the two rails is in the vertical plane, i.e. the

  vertical plane is clearly defined by this partial laser beam.

  One of the advantageous possibilities for defining the reference line

  rence consists in that the horizontal line lying in a vertical plane is formed by the partial laser beam extending transversely

relative to the two rails.

  The figures in the accompanying drawing will make it clear how

the invention can be realized.

  Figure 1 shows a system for measuring rails along a

  three-dimensional schematic representation.

  Figure 2 is a cross section of a worn rail, also schematically showing the position of the guide rollers and the rolling roller. Figure 3 is a top view, according to a representation

  schematic, of the receiving unit.

  Figure 4 is a longitudinal section of the receiving unit

according to figure 3.

  Figure 5 is a top view of the receiving unit according to the

  Figure 3 comprising pairs of guide rollers.

  FIG. 1 is a three-dimensional schematic representation of the system for measuring rails 1, comprising a transmitting unit 2 arranged on a rail 1 and a receiving unit 3 spaced therefrom, which is arranged on the same rail. The emission unit 2 is equipped with a laser whose laser beam 4 is oriented in the longitudinal direction of the rail. The laser beam 4 affects a diffuser 5a, transparent to light, from the reception unit 3; the diffuser 5a serves in this case as a surface

  predefined measurement 5. Behind the diffuser 5a, there is arranged a photore-

  receiver 6 made as a CCD camera 6a facing the laser beam 4. The CCD camera 6a has a rectangular matrix 6b having a plurality of pixels, which are arranged directly next to each other. The pixels are formed by light-sensitive sensor elements. Via an imaging optic 6c, the light spot of the laser beam 4 on the diffuser 5a is represented on the matrix 6b, so that

  the point of incidence or the position of the laser beam 4 on the measuring surface

  vertical line 5 oriented perpendicular to the longitudinal direction

  of the rail can only be determined electronically by the

  electrical output signals, provided by the incident laser beam 4, of the individual pixels. All the electrical and mechanical sub-assemblies of

  the receiving unit 3 are arranged on a solid base plate 3a.

  To improve the sensitivity, a narrow band interference filter is mounted in the ray path of the CCD camera 6a. The image of the laser beam 4 is thus displayed with a high contrast on the video image.

CCD camera 6a.

  The rail 1 is measured in that the receiving unit 3

  provided with two rolling rollers 7 which can be driven is displaced

  created in the longitudinal direction of the rail and the point of incidence of the radius

  laser 4 is detected each time, which moves on the surface of the

  sure 5 in the event of a change in the position of the rolling surface

  ment 8 of the rail. As the photoreceptor 6 is fixedly mounted on the

  base plate 3a, the position of the spoke 4 with respect to a position in

  recorded at the beginning of rail 1 constitutes an exact representation of the distance from rail 1, in horizontal and vertical direction, at the position of

respective measurement.

  To exploit more precisely the image of the ray on the matrix 6b, a processing of the resolution of the sub-pixels is used. In addition, in a quadratic area around the radius image, each image line and each image column are individually evaluated and the results are averaged. As a result, we obtain the position "precise to sub-pixels" of the image of the ray in the matrix 6b, which corresponds

  at the position of the laser beam 4 on the vertical measurement surface 5 orient-

  tee perpendicular to the longitudinal direction of rail 1 or can be converted to it and, in fact, due to the existing linear relationship

  between the object and the image. The point of incidence of the laser beam 4 on the diffu-

  seur 5a can be very precisely determined by adapting the position

  measured sub-pixels of the image of the radius of the diffuser 5a on the ma-

6b.

  The difference from the initial position is a measure

  sure of the distance of the measuring unit's carriage 3 from the ideal line.

  By position modification, we understand, in this case, the

  fication of the position of the highest horizontal point of the rolling surface 8 of the rail. As you can see in Figure 2 (and Figure 3),

  the horizontally mounted rolling rollers 7 are rotated

  read in the form of a cylinder, thanks to which it is guaranteed that the re-

  ception 3 rests, by means of its two rolling rollers 7, on two measuring points spaced, each time, at the highest horizontal support points 9 of the rolling surface 8 of the rail 1. Thus, one depends, depending on the shape of the running surface 8 along the rail 1, by raising or lowering the receiving unit 3 and, consequently, the measuring surface 5. The laser beam 4 is spatially stabilized in position, that is to say it maintains its position in space with high precision and thus represents the reference line of the system. The laser beam 4 is stabilized in position electronically, advantageously by means of an "electronic level"; it corresponds, in the example of embodiment, to a deviation

  +/- 1 mm for a length of the laser beam 4 of 100 m.

  The measurement surface 5 is connected to an operating electronics, which comprises a microprocessor and can be controlled by

  calculation programs. The operating electronics 10 read the position,

  tected by the CCD camera, of the image of the ray in a location-dependent manner and thereby determines the exact position of the laser beam 4 on

  the measurement surface 5. To determine the point of incidence of the direction

  main radiation of the laser beam 4, the operating electronics

  tion 10 is available through a special calculation program

  cial which, in a quadratic area around the image of the radius, individually assesses each row and each column and averages the results (0.2 mm per pixel). To obtain sufficient linearity and to increase the accuracy of the measurement, a measurement camera must

  be used having, relatively to their shape, quadratic pixels.

  To determine the distance between the transmitting unit 2 and the transmission unit

  reception 3, the reception unit 3 is provided with a distance sensor 1 1.

  The distance sensor 11 consists of a friction wheel 12, which rolls on the running surface 8 of the rail 1 and is connected, to detect the

  bearing length, to an incremental sensor connected to the electronic-

  than operating 10. In this way, the distance and / or modification of

  distance between receiving unit 3 and transmitting unit 2 can be

  tected with high precision. Furthermore, the friction wheel 12 also serves to detect the state of movement of the receiving unit 3 during

  operating electronics 10 and stop the drive motor

  13 of the emergency receiving unit. Figure 3 shows

  the drive motor 13 drives the wheels synchronously

  runners 7 by means of toothed belts 14 and

return pulleys 15.

  FIGS. 2, 3 and 4 show two rolling rollers 7, spaced apart in the longitudinal direction of the rail, rolling on the rolling surface of the rail 1, having an axis of rotation oriented horizontally transversely to the longitudinal direction of the rail and, for

  guide the receiving unit 3 on each side of the rail, guide rollers

  dage 1 7 leaning under the action of a force on the lateral surfaces 1 6

  of rail 1, which rollers are mounted vertically rotatably.

  For the best adaptation to the respective cross-section of the rail, the

  vertical height of the guide rollers 17 can be, each time,

  individually. In the exemplary embodiment according to FIG. 3, the rolling rollers 7 are arranged between the guide rollers 17. The distance from the axes of the rolling rollers 7 and the directly adjacent guide rollers 17, 18 is suitably equal, between simple and

  triple the diameter of the guide rollers 1 7, 18.

  The guide rollers 17, 18 have, on one side of the rail, a fixed axis of rotation and are applied, on the other side of the rail 1, under the action of a force on the lateral surface 16, which is done by a

  elastic force. The guide rollers 17, 18 are mounted in rollers.

articulated ball bearings.

  An alternative embodiment is shown in Figure 5 in which the guide rollers are arranged in pairs 17a, 18a each time on a common longitudinal support, extending in the longitudinal direction of the rail, fixed to the base plate 3a . Also, the pairs of guide rollers 17a, 18a have, on one side of the rail, in each case, fixed vertical axes of rotation and are supported, on the other side of the rail

  1, being stressed by an elastic force, on the lateral surface cor-

respondent 1 6.

  The rolling surface 19 of the rolling rollers has, as shown in FIG. 5, alternatively approximately at the center of the rolling roller 7, a radial groove 20, which guarantees

stable support at two points.

  The receiving unit 3 is equipped, to prevent the system from falling in the case of heavily worn rails, with a security system, which is integrated in the operating electronics 10. The security system comprises a sensor additional horizontal distance, which detects the distance from a reference point of the receiving unit 3 to the running surface 8 of the rail 1 and cuts off the drive motor 13

  when a limit value is exceeded.

  To measure two rails located close to each other in a plane, the laser beam 4 is divided into two partial laser rays

  horizontal 4a, 4b extending perpendicularly to one another

  tre, which are used to determine the difference in height of the two rails 1.

  This is done with respect to a horizontal line that is in

  a vertical plane, which is defined by the partial laser beam 4b extending per-

pendulum to the two rails 1.

Claims (19)

  1. System for measuring rails, in particular road rails   Lement for cranes, shelving service units, rolling wheel blocks, comprising an emission unit, arranged on the rail, which comprises a laser having at least one laser beam extending in the longitudinal direction of the rail. , and a receiving unit which can be driven which, on the same rail, is movable in the longitudinal direction of the rail and has at least one photoreceptor facing the laser beam, which generates an electrical output signal, caused by the incident laser beam, with reference to which the local position of the laser beam can be   determined on a vertical measurement surface, oriented transversely-   lying to the longitudinal direction of the rail,   characterized in that the photoreceptor (6) has a rectangular matrix   gular (6a) having a plurality of pixels (optical sensor elements) arranged directly next to each other, the electrical output signals of which are supplied to operating electronics (10), by means of which the point determination is carried out laser beam incidence   (4) spatially stabilized in position on the measurement surface (5), uni-   only electronically, by using the pixel output signals, and in that a distance sensor (11) is provided for detecting   a change in the distance between the transmission unit (2) and the transmission unit ception (3).   2. System according to claim 1, characterized in that the photoreceptor (6) is a CCD camera (6a), in front of which is arranged a diffuser (5a), transparent to light,   as measuring surface (5), which is shown optically on the ma- CCD camera (6a) (6b).   3. System according to one of claims 1 or 2,   characterized in that the point of incidence of the laser beam (4) on the diffuse   sor (5a) can be determined by adapting the measured position of the   sub-pixels of the image of the radius of the diffuser (5a) on the matrix (6b).   4. System according to claim 3,   characterized in that the adaptation is carried out by means of a calculation gram.   5. System according to one of claims 1 to 4,   characterized in that the operating electronics (10) have a mid croprocessor.   6. System according to one of claims 1 to 5,   characterized in that the distance sensor (11) has a wheel   friction (12) rolling on the running surface (8) of the rail (1).   7. System according to claim 6,   characterized in that the friction wheel (12) is connected to a sensor   step by step to detect the rolling length.   8. System according to claim 6, characterized in that the state of movement of the receiving unit (3)   can be detected by means of the friction wheel (12).   z20 9. System according to one of claims 1 to 8,   characterized in that the receiving unit (3) is remotely controllable.   10. System according to one of claims 1 to 9,   characterized in that the stabilization in position of the laser beam (4) is   carried out by means of an electronic level.   1 1. System according to claim 10,   characterized in that the stability in position corresponds to a deviation of + / -   1 mm for a rail length of 100 m.   12. System according to one of claims 1 to 11,   characterized in that, for a rail cross section made up of core and wing parts, at least two guide rollers in each case   (17, 18) separated in the longitudinal direction of the rail, mounted vertically-   ment in rotation, and applied under the action of a force to guide the receiving unit (3) are provided on the two lateral surfaces (16) of the rail   (1), as well as at least two rolling rollers (7) mounted horizontally   slowly rotating, rolling on the running surface (8) of the rail (1), and spaced apart in the longitudinal direction of the rail, having an axis of rotation oriented perpendicular to the longitudinal direction of the rail, of which   at least one is driven to drive the receiving unit (3).   13. System according to claim 12, characterized in that the vertical height of the guide rollers (17, 18)   is individually adjustable each time.   14. System according to claim 12 or 13, characterized in that, in the longitudinal direction of the rail, the roller   front bearing (7) is, in each case, arranged behind the guide rollers dage (17, 18) before.   15. System according to one of claims 12 to 14,   characterized in that the distance between the axes of the rolling roller (7) and the directly adjacent guide roller (17, 18) is between simple and   triple the diameter of the guide rollers.   1 6. System according to one of claims 1 2 to 1 5,   characterized in that, each time on one side of the rail (1), the guide rollers (17, 18) have a fixed axis of rotation and, on the other side of the   rail (1), apply under the action of a force on the lateral surface (16).   17. System according to claim 16, characterized in that the support of the guide rollers (17, 18) is carried out by an elastic force.   18. System according to one of claims 12 to 17,   characterized in that the guide rollers (17, 18) are mounted in   articulated ball bearings.   19. System according to one of claims 12 to 18,   characterized in that the guide rollers (17, 18) are arranged in pairs (17a, 18a) each time on a common longitudinal support,   extending in the longitudinal direction of the rail, which is arranged on the uni- reception tee (3).   20. System according to one of claims 1 2 to 1 9,   characterized in that in the rolling surface (19) rollers of   bearing, it is formed, in the center, a radial groove (20).   21. System according to one of claims 1 to 20,   characterized in that the receiving unit (3) is provided with a security system. 22. System according to claim 21, characterized in that the security system has, to detect the distance from a reference point of the receiving unit (3) to the rail (1), at minus a distance sensor (11).   23. System for measuring at least two rails located in   a plan, according to one of claims 1 to 22,   characterized in that the laser beam (4) is divided into two laser beams   partial (4a, 4b) horizontal, extending perpendicular to each other   tre, to determine the difference in height of the two rails (1).