Installation and method for measuring rolling parameters by means of artificial vision on wheels of railway vehicles

Abstract: Installation and process for measuring rolling parameters by means of artificial vision on wheels of railway vehicles. The installation comprises a rolling steel slab (2) with its guard rail, a wheel-position sensor (9), a laser generator (5), a camera (6), a controller (10) for illuminating and capturing the image, artificial-vision electronic equipment (11), a control computer (8) and a monitor (13). An interior illumination mirror interacts with the laser generator to obtain the profile of the wheel. The process consists in causing the wheel to run on the steel slab, activating the position sensor, throwing out a beam of laser light onto the wheel and generating an image corresponding to its profile or to its diameter, capturing this image and sending it to the analysis equipment, and transmitting the results of the analysis to the computer for it to process them and visualize them on the monitor.

Description: FIELD OF THE INVENTION The present invention refers to the field of the high-precision measurement of the rolling parameters on wheels mounted on railway vehicles which are moving at manoeuvring speed. Of these parameters, the most important include the following: thickness and height of the flange of the wheel, qR factor, i.e. the scope of the active face of the wheel flange, diameter of the wheel and distance between internal faces of opposite wheels. Similarly, according to the invention, a reproduction, including parameters, of the profile of the wheel is generated, making it possible to compare it with other standard profiles or to make any other type of measurement. The invention is embodied in an installation for measuring the said parameters and in a corresponding operating method. The installation of this invention may be constructed on any type of track where the vehicles move at manoeuvring speed, it being possible for it to be located inside the sheds or outside them. The measurements made on the vehicles which are moving over these tracks are processed and sent to rolling-stock maintenance centres so that operations for rectifying any deficiencies detected in the condition of the wheels can be carried out there. BACKGROUND OF THE INVENTION The prior art has already dealt with the contact-free measuring of parameters of surface structures. Thus, Patent ES-A-499 366 describes a track-borne movable measuring vehicle which carries an emitter and a receiver of laser rays as well as means for indicating and, if appropriate, storing the measurement data for the surface studied; Patent ES-A-2 054 398 relates to a track-borne vehicle for measuring the geometric parameters of a railway track using a proximeter and optical distance gauges; also, Patent EP-A-0 461 119 covers a device for interferometric measurement of surface structures which includes at least two laser sources and which is used to measure the phase difference in pairs of laser particles at set measurement points on the surface investigated. All these measurement systems apply to fixed surface structures, such as tracks, tunnel openings and defiles, but, unlike the present invention, they do not make it possible to measure parameters of moving objects, such as the wheels of a vehicle. Similarly, Patent EP-A-0 467 984 protects a plant for detecting the wheel profile of trains with the aid of an illuminating unit, a scanning unit, a measuring unit and a data processor. However, the technological principles on which said plant is based differ from those used to develop this invention. Furthermore, from DE-A-4 312 876 a device is known for measuring and determining the profile variation of the treadband and flange of a wheel in railway vehicles, where the portions subject to wear in the wheel rim are measured by detectors sensing a laser beam and the real profile of the wheel is evaluated by comparison with the rated profile of same. The preamble of the appended claim 1 is based on this document. From US-A-4 798 963 an apparatus is known for monitoring and measuring the profile quality of a wheel in a railway vehicle while the latter is passing through a measuring range which includes auxiliary rails, diameter sensing devices and wheel tread profile quality sensing devices, the signals provided by the sensing devices being supplied to signal processing and evaluating circuits which provide the desired information on the wheel condition. From US-A-5 090 811 a non-contacting system for measuring the radius of a curved surface is known, where a light source illuminates the surface along the intersection of same with a plane including the radius to be measured, and a lens is used to project an image of said intersection onto a video camera, which generates a video signal which is provided to a microcomputer for calculating the surface radius from the image data included in said signal. From WO90/12720 a plant for detecting a wheel profile on a passing train is known, where an illumination unit includes a light source which transmits a structured light towards the wheel profile, a scanning unit scans the illuminated area, a measuring unit scans the sideways position of a wheel on a rail, and a data processing unit comprises a line which transmits the measurement data to a central computer or other surveillance equipment. SUMMARY OF THE INVENTION Starting from the above state of the art, the invention consists in the generation of a planar beam of laser light which falls upon the wheel to be measured in its lower part by virtue of a rail which is specially designed to act as support for the wheel of the train on the flange or in its outermost part, depending on whether the diameter or the profile of the wheel is being measured. In this way, it is possible to take images of the projection of the circumference of the wheel, formed by the laser beam, in the zone with the lowest instantaneous speed of movement and with reference to the support rail. Clearer, less distorted images are thus obtained at greater speed. According to the invention, an installation for the measurement of the said rolling parameters comprises a steel slab on which the wheel which it is desired to measure runs, a guard rail which interacts with said steel slab to prevent derailment, a wheel-position sensor which emits a signal when the wheel is in a suitable position for measurement, a laser generator which, upon being activated by said signal, throws a planar beam of laser light onto the wheel, a camera with lens and filter which captures the image generated by said planar beam of light, a controller for illuminating and capturing the image which synchronizes the acquisition of the image through the wheel-position sensor, and high-resolution artificial-vision electronic equipment which analyses the image captured by said camera and which sends the measurements obtained to a central control computer where they are processed and visualized. The image generated by the planar beam of light may consist of the profile of the wheel with reference to the steel slab, in which case said image is obtained with the aid of an interior illumination mirror, or other laser generator, which interacts with the laser generator already mentioned. As an alternative, the image generated by the planar beam of light may consist of a line formed on the wheel and representing an arc of circle that allows to calculate the diameter of the latter. According to the invention, the equipment for measuring the profile of the wheel together with the distance between internal faces and the equipment for measuring the diameter thereof may be incorporated inside one and the same unit. Alternatively, it is also possible for the equipment for measuring the profile of the wheel together with the distance between internal faces and the equipment for measuring the diameter thereof to be autonomous and capable of functioning independently of each other. Except for the central control computer, which is common to all the wheels which have to be measured, the remaining elements of the installation of the invention corresponding to one wheel are repeated for the opposite wheel. Moreover, a method for measuring rolling parameters by means of artificial vision on wheels mounted on railway vehicles which are moving at manoeuvring speed, in which use is made of the installation of the invention, consists in that, for measuring the profile of the wheel, the latter is caused to run, resting via its outermost part on the steel slab, whereby the wheel-position sensor is activated, giving rise to the laser generator throwing out a planar beam of laser light onto the wheel and to an image corresponding to the profile of the wheel being generated with the aid of the mirror or other laser generator; this image is captured with the corresponding camera and is sent to the artificial-vision electronic analysis equipment; and the measurements and parameters of the profile of the wheel obtained in said analysis equipment are transmitted to the central computer for it to process them together with those of the opposite wheel and generate the wheel-measurement report, the result obtained being visualized on the monitor. An alternative method for measuring rolling parameters by means of artificial vision on wheels mounted on railway vehicles which are moving at manoeuvring speed, in which use is also made of the installation of the invention, consists in that, for measuring the diameter of the wheel, this is caused to run, resting on the steel slab via the flange, whereby the wheel-position sensor is activated, giving rise to the laser generator throwing out a planar beam of laser light onto the wheel and to an image in the form of a line representing the diameter of the wheel being generated onto said wheel; this image is captured with the corresponding camera and is sent to the artificial-vision electronic analysis equipment; and the measurement of the diameter of the wheel obtained in said analysis equipment is transmitted to the central computer for it to process it and generate the wheel-measurement report, the result obtained being visualized on the monitor. The measurement of the profile of the wheel together with the distance between internal faces and the measurement of the diameter thereof may be achieved with measurement components which form part of a single unit. As an alternative, it is possible for the measurement of the profile of the wheel together with the distance between internal faces and the measurement of the diameter thereof to be achieved with measurement components which form part of two units capable of functioning independently of each other. The main features of the installation and method of the invention are described in the characterizing portions of the independent claims 1 and 7-8. respectively, while preferred embodiments of the invention are shown in the remaining dependent claims 2 to 6, 9 and 10. BRIEF DESCRIPTION OF THE DRAWINGS A more detailed description of the invention is now given, with reference to the appended drawings, in which an installation embodied according to the invention is diagrammatically illustrated. Figure 1 shows the installation of the invention applied to the measurement of the profile of a wheel; this figure has been broken down into two parts, the right-hand part of which shows a view of the wheel taken through its rolling wheel rim, whilst the left-hand part shows a view of the wheel taken through one of its faces, Figure 2 shows the installation of the invention applied to the measurement of the diameter of a wheel, and Figure 3 shows a sketch of the complete measuring installation according to the invention. DETAILED DESCRIPTION OF THE INVENTION With reference, firstly, to Figure 1 of the drawings, it is pointed out that, for measuring the profile of a wheel (the same measurement on the opposite wheel is carried out at the same time), the installation of the invention comprises a specially designed rolling support or steel slab 2 on which the outermost part of the wheel 1 which it is desired to measure is caused to roll and which has a guard rail 3 which prevents derailment. Therefore, the rolling zone which it is desired to analyse remains free, this free zone being equal to at least 75 mm for a wheel-rim width 135. On one side of the steel slab 2 is a wheel-position sensor 9 which, when the wheel passes, sends a signal to a laser-beam generator 5 which is then activated and throws out a planar beam of laser light onto the wheel. With the aid of a mirror 7 for interior illumination (or with the aid of another laser generator), this beam generates the shaded profile 4. The image of this profile is captured by a camera 6 equipped with a lens and filter and is sent, to be analysed, to high-resolution artificial-vision electronic equipment 11, illustrated in Figure 3. The position of the profile 4 with respect to the stationary parts 2 and 3 makes it possible to obtain the distance between internal faces DCI by computing the values for both wheels. The installation of the invention which is shown in Figure 2 of the drawings, prepared for measuring the diameter of a wheel, differs, in basic terms, from the installation shown in Figure 1 insofar as the image is taken perpendicularly. In the installation of Figure 2, the wheel 1 runs while resting via its flange and guided by means of the steel slab 2 and the guard rail 3. As in Figure 1, the position sensor 9 emits a signal as the wheel passes and thus activates a laser generator 5 which throws out a planar beam of laser light onto the wheel, a line 12 then being generated on the latter. The image of this line is captured with the camera 6 and analysed by the artificial-vision electronic equipment 11. The measurement installation of the invention is shown in its entirety in the sketch in Figure 3. The rolling steel slabs 2 serve as support for the cameras 6 and the laser generators 5. A controller 10 for illuminating and capturing the image serves to synchronize the acquisition of the images by means of the position sensors 9. These images are analysed by the vision equipment items 11 which send the measurements and parameters of the profile of the wheel, as well as the measurement of its diameter, to the central control computer 8 where said data are processed to generate the measurement reports for the vehicles, the result being visualized on the monitor 13. A control cabinet 14 houses the controller 10 and the artificial-vision equipment items 11, as well as other components of the system. In the sketch in Figure 3, the part indicated by MD is prepared for measuring the diameter of the wheels, whilst the part marked with MP is intended for measuring the profile and the distance between internal faces of the wheels. The operating method of the installation according to the invention may be inferred from the preceding description of the figures in the drawings and consists, in basic terms, in that a position-detection system (position sensor 9) activates, for each wheel of the vehicle which is passing, the acquisition of the corresponding image by means of the cameras 6 which are equipped with a filter having the same frequency as the wavelength of the laser produced by the generator 5, thus eliminating the influence of ambient light. The image picked up by the cameras is analysed and corrected geometrically in real time by the high-resolution vision equipment 11, thus making it possible to obtain a high level of precision in the measurements. The invention also makes it possible for acceptable passing speeds to be achieved on vehicles with a wheel base of 1800 mm. As may be ascertained from the preceding description, the installation consists of two distinct parts, the first of which consists of the equipment for measuring the profile of the wheel, whilst the second is formed by the equipment for measuring the diameter of said wheel. These two parts may form a single installation or, alternatively, may operate independently of each other. The preceding description of the invention has been made with reference to what constitutes the currently preferred illustrative embodiment thereof. However, as experts in the field will understand, some modifications of form and detail may be made in the installation described and illustrated, as in the component arrangement, without thereby departing from the scope of the invention. Therefore, the intention is that the scope of the invention should be limited solely and exclusively by the contents of the appended claims.

Claims: Installation for measuring rolling parameters by means of artificial vision on wheels mounted on railway vehicles which are moving at manoeuvring speed, in which, amongst other parameters, the thickness and the height of the flange of the wheel, the qR factor, i.e. the scope of the active face of the wheel flange, the diameter of the wheel and the distance between internal faces of opposite wheels are measured, and in which a reproduction with parameters of the profile of the wheel is generated, the installation comprising a steel slab (2) on which the wheel (1) which it is desired to measure runs, a guard rail (3) which interacts with said steel slab to prevent derailment, and a wheel-position sensor (9) which emits a signal when the wheel is in a suitable position for measurement, characterized by further comprising a laser generator (5) which, upon being activated by said signal, throws a planar beam of laser light onto the wheel, a camera (6) with lens and filter which captures the image generated by said planar beam of light, a controller (10) for illuminating and capturing the image which synchronizes the acquisition of the image through the wheel-position sensor (9); and a high-resolution artificial-vision electronic equipment (11) which analyses the image captured by said camera and which sends the measurements obtained to a central control computer (8) where they are processed and visualized on a monitor (13). Installation according to Claim 1, characterized in that the image generated by the planar beam of light consists of the profile (4) of the wheel (1) and is obtained with the aid of an interior illumination mirror (7), or other laser generator, which interacts with the laser generator (5). Installation according to Claim 1, characterized in that the image generated by the planar beam of light consists of a line (12) on the wheel (1) which represents an arc of circle allowing to calculate the diameter thereof. Installation according to any one of Claims 1 to 3, characterized in that the equipment for measuring the profile of the wheel (1) and the equipment for measuring the diameter thereof are incorporated inside one and the same unit. Installation according to any one of Claims 1 to 3, characterized in that the equipment for measuring the profile of the wheel (1) and the equipment for measuring the diameter thereof are autonomous and capable of functioning independently of each other. Installation according to any one of the preceding claims, characterized in that all the elements of the installation corresponding to one of the wheels to be measured are repeated for the opposite wheel, with the exception of the computer (8) which is common to the whole installation, making it possible to obtain the distance between internal faces. Method for measuring rolling parameters by means of artificial vision on wheels mounted on railway vehicles which are moving at manoeuvring speed, in which use is made of an installation according to one or more of Claims 1 to 6, characterized in that , for measuring the profile of the wheel (1) and the distance between internal faces, the wheel is caused to run, resting via its outermost part on the steel slab (2), whereby the wheel-position sensor (9) is activated, giving rise to the laser generator (5) throwing out a planar beam of laser light onto the wheel and to an image corresponding to the profile (4) of the wheel being generated with the aid of the mirror (7) or other laser generator; this image is captured with the camera (6) and is sent to the electronic analysis equipment (11); and the measurements and parameters of the profile of the wheel obtained in said analysis equipment are transmitted to the computer (8) for it to process them and generate the wheel-measurement report, the result obtained being visualized on the monitor (13). Method for measuring rolling parameters by means of artificial vision on wheels mounted on railway vehicles which are moving at manoeuvring speed, in which use is made of an installation according to one or more of Claims 1 to 6, characterized in that , for measuring the diameter of the wheel (1), this is caused to run, resting on the steel slab (2) via the flange, whereby the wheel-position sensor (9) is activated, giving rise to the laser generator (5) throwing out a planar beam of laser light onto the wheel and to an image in the form of a line (12) corresponding to the diameter of the wheel being generated onto said wheel; this image is captured with the camera (6) and is sent to the electronic analysis equipment (11); and the measurement of the diameter of the wheel obtained in said analysis equipment is transmitted to the computer (8) for it to process it and generate the wheel-measurement report, the result obtained being visualized on the monitor (13). Method according to either of Claims 7 or 8, characterized in that the measurement of the profile of the wheel and of the distance between rims and the measurement of the diameter thereof are achieved with measurement, components which form part of a single unit. Method according to either of Claims 7 or 8, characterized in that the measurement of the profile of the wheel and of the distance between rims and the measurement of the diameter thereof are achieved with measurement components which form part of two autonomous units capable of functioning independently of each other.

Inventors: GOMEZ GOMEZ CARLOS JAVIER, SANCHEZ REVUELTA ANGEL LUIS, GOMEZ GOMEZ, CARLOS JAVIER, SANCHEZ REVUELTA, ANGEL LUIS
Applicants: TALGO PATENTES, PATENTES TALGO, S.A.
Application year: 1996
Main classification: G01B11
IPC codes: B61K9, G01B11