Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B11/00—Measuring arrangements characterised by the use of optical techniques
  • G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B11/00—Measuring arrangements characterised by the use of optical techniques
  • G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
  • G01B11/028—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness by measuring lateral position of a boundary of the object
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B11/00—Measuring arrangements characterised by the use of optical techniques
  • G01B11/14—Measuring arrangements characterised by the use of optical techniques for measuring distance or clearance between spaced objects or spaced apertures

Definitions

• the invention relates to the real-time measurement of relative position data and / or geometric dimensions of a moving body using optical measuring means.
• a particularly vorteilhaf ⁇ ter application case concerns the monitoring of changes in a wheel of a railway vehicle while driving.
• the lateral offset of a wheel ei ⁇ nes rail vehicle against the rail is measured even while driving, by shone only on the lower part of the rail from the vehicle and the light reflected therefrom by photodiodes as optical sensors, which also are mounted on the vehicle is detected.
• a side edge of the rail shadows a portion of the reflected light from a portion of the sensors. From the position of the shadow edge on the sensors, the lateral wheel offset can be calculated.
• a light source for example, a laser can be used.
• the position of a rail vehicle relative to a rail is measured by a laser light beam focused as well as possible at a first angle on a surface of the rail and by the light spot through a directed from a different angle to the first angle Ka ⁇ mera, which is formed by a lens and a photocell array, is imaged. Since the light spot on the must occur to the lens center point of the various elements of the laser beam ⁇ defined plane, the position of the light ⁇ flecks can be calculated relative to the camera from the position of images of the light spot on the photo cell array.
• cross-sectional area is either a La ⁇ serstrahl with the cross-sectional area of a straight line shape of the o- used with the cross-sectional form of several, lying along a straight line points.
• the image of the light surface caused by the laser beam on a rail taken by a camera from a defined position enables the distance of the rail to the camera and the calculation of a part of the outline of the cross-sectional area of the rail.
• the above-discussed detection means based on laser light sources and photocells are mounted on the bogie of a rail vehicle.
• the movement of the bogie relative to the frame of the rail vehicle is preferably detected by mechanical sensors.
• the geometry of the running surface of a wheel of a rail vehicle is measured by the wheel slowly rolling over a measuring rail and being illuminated by a collimated laser beam.
• the image of the illuminated area is recorded by a camera and evaluated by a computer including the data at which point of the measuring rail the wheel is applied in each case.
• a device which is integrally ⁇ arranged on a rail vehicle at the level of the wheels and - as discussed further above - has a lighting ⁇ device and a camera, which are aligned at different angles to a rail - to measure - according to the principle discussed above - this.
• the device is enclosed by a housing into which compressed air is passed through a hose. In the range of the required window of the housing, the compressed air flows out from the housing and prevents ver ⁇ so that pollution from the outside arrives at the windows.
• a detector surface is beschrie ⁇ ben for use as a control surface for a data processing system which detek- advantage of the fact the impact of a light pulse on it and the location coordinates of the impact point on it.
• the detector surface is constructed as a planar optical waveguide.
• small-area photoelectric sensors are attached ⁇ introduced at the planar optical waveguide, to which on the light wave guide incoming light is coupled out and causes an electrical signal.
• Paral ⁇ lel with the optical waveguide extends to this one layer with photoluminescent properties. Light in the appropriate wave spectrum, which strikes the layer arrangement, is converted at the photoluminescent layer into longer-wave light, which propagates in the waveguide and thereby reaches the photoelectric sensors.
• the inventor has set itself the task of improving the continuous measurement of position and geomet ⁇ rieteil an operatively moving object. It should be possible to make more measurements per unit of time, the volume of data obtained in the measurement should still be easily transferable to the data processing system and the necessary devices should be robust and inexpensive.
• the invention will also be advantageous to applic ⁇ bar, position and geometry data of a wheel of a railway vehicle running réelle ⁇ contained in operative ride take.
• a planar optical position detector is arranged, over which runs the shadow boundary of the shadow cast by the object to be measured.
• the planar optical position detector is - as the detector surface according to the above-described WO 2010/006348 Al - formed as a planar optical waveguide with integrated fotoluminesz zentem, wherein the optical waveguide spaced from each other relatively small-area photoelectric sensors are ⁇ introduced , where light from the waveguide mode is disconnected and causes an electrical signal.
• the electrical signals are evaluated in a connected data processing system.
• Changes in the shadow boundary on the planar optical position detector cause signal changes to a plurality of photoelectric sensors. From the amplitude of these signal changes by the data processing system on the change of the shadow boundary on the surface position detection tor concluded and further on a change in the position or the course of the contour of the object to be measured.
• the measuring principle based on luminescence waveguide allows for extremely fast measurements and very fast reading of the obtained data. So are also very short-term or perio ⁇ disch well be detected with high frequency repetitive movements or dimensional changes.
• planar optical position detector is very cost per unit area compared to other optical position detectors. Therefore allows Messprin ⁇ zip large-scale applications of the invention which have not been realized from elleli ⁇ chen reasons.
• the proposed position detector is typically present as a flexible plastic film. He does not need to be arranged in a plane, but it can also be applied to a ge ⁇ curved surface.
• the proposed position detector can be implemented easily as big ⁇ area that for the picture (or "monitoring") of a large area to be imaged no lenses are required which are required in conventional detectors for the light coming from the large area to be imaged light on to focus the much smaller detector area
• the detector arrangement according to the invention can be made much flatter than detector arrangements according to the prior art.
• Fig. 1 shows a stylized side-sectional partial view of the essential parts for understanding the invention in an exemplary inventive measuring arrangement.
• the moving body to be measured is a wheel 1, which - as indicated by directional arrows - can both rotate about its axis, and can also be displaced in a direction normal thereto.
• a lighting unit 2 and a De ⁇ detector unit 4 are attached on a - not shown - body relative to which relative movement of the wheel 1 is to be detected.
• the wheel 1 could typically be a wheel of a rail vehicle.
• the purpose of the measurement would then be to detect deflections of the wheel relative to the rail vehicle or the bogie in the vertical direction and changes in the shape of the tread of the wheel in real time and in a data processing system document.
• Lighting unit 2 and detector unit 4 would then be attached to the frame of the rail vehicle or on the bogie on which the wheel is held.
• light beams 3 are sent to the detector unit 4.
• the light beams 3 are as well as possible collimated with respect to one another (that is to say aligned parallel to one another) or aligned as well as possible starting from a common real or virtual punctiform light source.
• the object to be measured in the example illustrated a wheel 1, is arranged between the illumination unit 2 and the detector unit 4.
• the ⁇ ses wheel 1 protrudes into the flooded by the light beams 3 Vo ⁇ lumen so that it casts a shadow whose boundary line passes over the detector unit. 4
• the shadow boundary on the detector unit 4 is 29o ⁇ ben. Shifting the shadow boundary causes 4 signals in the detector unit.
• the core of the illumination unit 2 is a light source 2.1, which is best realized by a light-emitting semiconductor diode and a downstream lens.
• the light beams 3 can be best collimated to each other.
• the arrangement can be very well insensitive to ambient light influences.
• the light source 2.1 including the downstream lens it is advisable to cover the light source 2.1 including the downstream lens by a transparent to the emitted light disk 2.4 outwards to protect them from dirt and mechanical damage.
• a transparent to the emitted light disk 2.4 inwards to protect them from dirt and mechanical damage.
• form 2.4 includes by a back open on one side to the light exit side of housing 2.2 and into the housing 2.3 2.3 Air is pumped through ei ⁇ ne line passing through the aperture from the light exit side again escapes from the housing 2.3. This ensures that the transparent pane 2.4 less dirty or may not even dirty in dusty or foggy environments.
• the detector unit 4 preferably has a housing 4.2, which has to the side at which light must be able to penetrate, an opening through which air flows, to which the air through a Lei ⁇ tion 4.3 elsewhere in the housing 4.2 is guided into it.
• the sensitive Kern Western Immunot the detector unit 4, namely that of the planar optical position detector 4.1 to the housing opening to be protected by a transparent pane 4.4 before mecha ⁇ African damage and contamination.
• the disc should be attached ⁇ assigns 4.4 as close to the area optical position detector 4.1, preferably at all abut it.
• the planar optical position detector 4.1 is a planar optical waveguide which contains photoluminescent particles and which has on one side a plurality of distributed, small-area photoelectric sensors 4.1.1, which are able to extract and detect light from the waveguide mode, so that an electrical signal is generated in dependence on the intensity of the light coupled out at the respective point.
• the photoluminescent particles for example dye molecules or semiconductor nanoparticles, convert ambient light into scattered light of longer wavelength. This light is largely coupled into the waveguide and spreads out in it. For several reasons, the light intensity in the waveguide decreases with increasing distance from the point at which the luminescence has taken place, and thus also the electrical signal generated at the respective photoelectric sensors.
• photoelectric sensors By a plurality of photoelectric sensors are arranged at a distance from one another on the optical waveguide can be deduced from the ratio of the measured signal strengths at the individual photoelectric sensors with mathematical methods that can be automated by data on the impact position of the light beam triggering the luminescence, wherein the achievable spatial resolution is often finer than the distance between the adjacent photoelectric sensors.
• Photodiodes based on silicon, whose active cross-sectional area is, for example, 0.36 mm 2 are usually used as photoelectric sensors. Depending on the desired spatial resolution may be between adjacent photoelectric sensors 15 to 150 mm distance.
• planar optical position detector 4.1 can be read extremely quickly and it can extremely large number of position measurements per unit time, typically 100,000 measurement solutions per second.
• mög ⁇ Lich as with an extreme Zeitlupenka ⁇ mera an extremely high temporal resolution of observation.
• the signals generated by the photoelectric sensors of the planar optical position detector 4.1 are read into a data processing system (not shown) and evaluated.
• a data processing system not shown
• the detection area is divided into two differently illuminated areas of the illumination unit 2 by the shadow unit described above, wherein the one surface area is illuminated homogeneously and the otherêtnbe ⁇ rich is not illuminated at all, , the course of the shadow border are calculated on the detection surface quickly through the verarbei ⁇ treatment plant by a kind of interpolation from the measurement results of the individual photoelectric sensors.
• the intensity of the light beams 3 emitted by the illumination unit 2 can fluctuate at a specific frequency and the photoelectric sensors 4.1.1 can be followed by a frequency filter whose passband is set to this frequency. This can be well suppressed by ambient light interference effects.
• the minimum time interval between aufeinan ⁇ of the following measurements may be 1 ⁇ (corresponds to a measurement frequency of 1 MHz) and the frequency with which the light beams 3 can be switched on and off 100kHz (period 10 is, 5 is on and 5 ⁇ off).
• the measuring principle according to the invention that can be realized easily.
• 5 measured values can be recorded in each case, which then correspond to the light intensity at the point of a detector.
• the speed of the Ra ⁇ des 1 is measured by the data processing system, it can be checked whether repeats of part of the observed shadow boundary or even the entire observed shadow boundary in time with the rotation of the wheel 1 or an integer multiple clock repeat it. This is then a clear indication of points on the wheel 1, which differ from the other rotational symmetry.
• the example "wheel of a rail vehicle” is the first appearance of such a measurement result and the one-time sudden shift of the entire observing shadow limit an indication of a damaged spot on a railway track. In conjunction with a tachograph can be found quickly with the measurement method, this defective location.
• a permanent shift of the shadow boundary without its shape has changed is an indication of a permanent re ⁇ relative displacement of the measured body. This can be done by the example of the rail vehicle by changing the elasticity of the suspension, which may indicate a corresponding Materialermü ⁇ tion.
• a permanent change in shape of the shadow border is an indication that something has been removed or applied evenly. At the instance of the wheel of the rail vehicle, slow uniform wear over the circumference would be typical. Permanent changes in brightness that do not follow the movements of the shadow boundary are a strong indication of contamination of one of the protective transparent panes 2.4 or 4.4.
• the entire surface of the flächi ⁇ gen optical position detector 4.1 may be a single continuous optical waveguide to which photoelectric sensors 4.1.1 are attached in some places, these being at both the surface edges as can also be arranged on remote surface areas.
• the surface of the optical position detector 4.1 is subdivided into a plurality of partial areas insulated from one another with respect to optical waveguides, each partial area being equipped with a plurality of photoelectric sensors 4.1.1 is. Since light signals which impinge on a single partial surface can thus not influence the sensor signals from the other partial surfaces, the evaluation of the overall result is simplified and less error-prone.
• a preferred embodiment of the invention is to enem part at which the lighting unit 2 and detecting unit 4 are mounted immobility ⁇ Lich each other, as a kind of diaphragm secured a template 5 which projects into the flooded by the light beams 3 volume and to be measured together with the Object 1 limits a slot through which light rays 3 reach the detector unit 4.
• the illuminated surface of the optical Posi ⁇ tion detector 4.1 is better limited.
• the template 5 may be formed, for example, by a sheet metal part whose the object 1 to be monitored facing edge of the local contour of the article 1 is approximately formed. . Before ⁇ Trains t the template 5 is - as shown in Figure 1 indicated - relative to the illumination unit 2 and detecting unit 4 in an adjustable Po ⁇ sition mountable, so that the gap to the monitored object while but no collision on ⁇ is as narrow as possible but occurs.
• the measurement principle according to the invention can be usefully employed particularly in such Before ⁇ directions, comprising relative to each other moving parts, whereby its relative position or its geometry to be measured with respect of a part of a relative thereto perio ⁇ disch repetitively moving the other part. It is particularly valuable for monitoring those periodically recurring moving parts, which are so worn by operational stresses that they need to be serviced or replaced several times during the usual life of the device.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Length Measuring Devices By Optical Means (AREA)

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• 2011
  • 2011-10-20 AT ATA1534/2011A patent/AT511200B1/de not_active IP Right Cessation
• 2012
  • 2012-09-24 EP EP12787628.2A patent/EP2769175A1/de not_active Withdrawn
  • 2012-09-24 JP JP2014536062A patent/JP2014532185A/ja active Pending
  • 2012-09-24 CN CN201280051647.6A patent/CN103890538A/zh active Pending
  • 2012-09-24 WO PCT/AT2012/050142 patent/WO2013056289A1/de active Application Filing
  • 2012-09-24 KR KR1020147013208A patent/KR20140079489A/ko not_active Application Discontinuation
  • 2012-09-24 US US14/351,997 patent/US20140240719A1/en not_active Abandoned

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