WO2012159766A1

WO2012159766A1 - Radioscopy method for generating two radioscopic images

Info

Publication number: WO2012159766A1
Application number: PCT/EP2012/002233
Authority: WO
Inventors: Klaus Bavendiek
Original assignee: Yxlon International Gmbh
Priority date: 2011-05-24
Filing date: 2012-05-24
Publication date: 2012-11-29
Also published as: DE102011102334A1

Abstract

The invention relates to a radioscopy method for generating two radioscopic images of at least one spoke 4, 5 and a spoke coupling of a wheel 3 in a radioscopy installation with an X-ray tube 1 and at least one X-ray detector 7, 9 for estimating the depth position of potential errors 6, wherein the X-radiation 2 emitted from the X-ray tube 1 passes through at least two spokes 4, 5 and the associated spoke couplings, and the part of the X-radiation 2 that passes through the first spoke 4 strikes the active surface 7a of an X-ray detector 7 arranged in a first detection position 8, and the part of the X-radiation 2 that passes through the second spoke 5 strikes the active surface 7a, 9a of an X-ray detector 7, 9 arranged in a second detection position 10, wherein the wheel 3, between the generation of the first radioscopic image and the generation of the second radioscopic image, is rotated until the first spoke 4 is in the position previously occupied by the second spoke 5.

Description

X-ray examination method for the preparation of two X-ray fluoroscopic images

The invention relates to an X-ray fluoroscopy method for generating two X-ray fluoroscopic images of at least one spoke including spoke connection of a wheel in an X-ray fluoroscopy system for estimating the depth of a potential error. From the prior art it is known to make a two-dimensional transillumination of a wheel. For this purpose, either a visual check in the live image on errors contained in the wheel, such as blowholes, performed or the test is carried out with an automatic error detection system. However, these known methods have the problem that they can not determine the depth of the detected error in the wheel based on the recorded image.

If this third dimension is of importance, the wheel to be examined is examined by means of a CT method, whereby the information obtained for each individual voxel within the wheel to be screened can also be used to determine the depth of the error found. For very flat objects, a laminography method can be used instead of a CT method. The disadvantage of these two methods - CT and laminography method - compared to conventional two-dimensional fluoroscopy, however, is the significantly longer image acquisition time in the former method. This results from the fact that as a rule 180 to 720 images of a region filling the detector input screen are necessary in order to be able to calculate a reconstruction in three dimensions.

Moreover, it is known to use a stereo-radiographic technique to obtain information about the third dimension of an error present within the test piece to obtain. Two fluoroscopic images of the test part, here a wheel, are taken from two different angles. On the basis of the trigonometric functions and the geometric specifications for the respective arrangement when recording the two fluoroscopy images, the depth of a detected error can then be estimated. In such a method automatically results in at least one mechanical position per test position in addition, resulting in a doubling of the total image recording time for a test part compared to the above-described two-dimensional detection using a fluoroscopic image. This can be illustrated by comparison of the test times for the first-described two-dimensional method and the stereo radiography method described last: The test time in two-dimensional method per test part is n * (t _ba + t _m) - t _m + t _a + t _AU3 wherein t _ba, the image pickup time, t _m is the time for the movement to the next mechanical position, _a t the Einförderzeit of the specimen into the system, t _from the Ausförderzeit of the test piece from the system and n is the number of test positions indicates. In contrast, the test time of a test piece by means of the three-dimensional stereo radiography is 2 * n * (t _ba + t _m) - t _m + t _a + t _AU3.

In normal fluoroscopy, an error can only be detected in two dimensions. The depth expansion can be estimated from the gray value difference. However, there is no clear information about the actual location of the error at depth in a fluoroscopy procedure. Now, however, it is often the case with wheels to know whether the defect is so close to the surface that it reaches the surface after the finishing of the wheel (eg polishing), which is done by removing a thin layer of material and thus the wheel will committee. It is therefore the task to develop a method which forms the basis for determining the depth of an error within an X-ray method. Rades sought to determine, with the time required for this compared with the known methods, in particular stereo radiography and the CT method is to be shortened. According to the invention, this object is achieved by a method having the features of patent claim 1. In order to check the spoke together with spoke connection of a wheel in an X-ray illumination system, an X-ray tube and at least one X-ray detector are required according to the invention. According to the invention, one X-ray tube emits X-rays, which radiate through at least two spokes together with associated spoke connections. Either two separate X-ray detectors are used to record the two X-ray fluoroscopy images of these two spokes together with the associated spoke connections, or a single X-ray detector is moved back and forth between the two locations, which are referred to as detection positions, or a detector is sufficient large entrance area, which can simultaneously detect at least two spokes or spoke connections. In order to obtain two fluoroscopic images of the same spoke including Speichenanbindung at different angles, as is necessary to later determine the depth position information of about any error found from these two fluoroscopic images, according to the invention, the wheel is first positioned so that the spoke to be examined together with Speichenanbindung is in a position in which the fluoroscopic image is taken by the X-ray detector in the first detection position, and then the wheel is rotated so that this first spoke is in such a position that allows the recording of a fluoroscopic image in the second detection position of the X-ray detector. This second detection position was taken during recording in the first detection position of the first spoke of a second spoke. Based on the geometrical specifications of the entire fluoroscopy system, which is uniquely determined by the individual positions of the X-ray tube, wheel and detector positions, two measurements are obtained. Illumination images of one and the same spoke including spoke attachment at different angles of incidence. On the basis of these two fluoroscopic images recorded from different angles of incidence, the depth position of a potential error can then be determined by means of the trigonometric functions because of the known geometric relationships of the abovementioned individual parts. This determination is a purely mathematical method which is known to the person skilled in the art, so that it need not be discussed here. It is also known to the person skilled in the art how the geometrical position between the X-ray tube, wheel with the first and second spokes and associated spoke connections and the detection positions of one X-ray tube or two X-ray tubes must be designed, thus recording the spokes in question including spoke connections can be done.

For such a method of the invention is required, if one uses two Rontgendetektoren an image pickup time of n * (t _ba + t _m) - t _m + t _a + t _off. The meanings of the variables used correspond to those described above for the state of the art

Technology executed variables. If one compares this time with the time specified in the prior art for stereo radiography, one obtains a saving compared to the same of n * (t _ba + tj.

If the inventive method instead of two detectors, as described in the previous paragraph, carried out with only a single detector, which must be moved back and forth between the two detection positions, so would the time for recording compared to the inventive solution described above by n * (t _ba + t _DDA ), where t _{DDA is} the movement time for the detector position change. The formula for a full test time with a single back and forth to be moved X-ray detector would amount to 2 * n * t _ba + (n - l) * t + n * _m t _DDA + t _a + t _off. A preferred embodiment of the method according to the invention uses two X-ray detectors, which are preferably identical, of which the first X-ray detector in the first detection position and the second X-ray detector in the second detection position are fixed. This results in the already mentioned above enormous saving of time for the preparation of the two required fluoroscopic images under different angles of incidence compared to the one-detector solution, which, however, is paid for by a higher financial cost due to the second detector required.

Another preferred embodiment of the method according to the invention provides that only one X-ray detector is used, whose active area is so large that at least two spokes radiated spokes including Speichenanbindung be detected simultaneously. However, this has a financial disadvantage compared to the solution with two detectors, since the price of the detectors increases disproportionately with the area. This saves the synchronization of the images of two detectors and can make do with fewer test positions on larger wheels.

The alternative solution using only one X-ray detector, which is moved between the creation of the two X-ray fluoroscopy images between the first detection position and the second detection position, although longer than with two fixed detectors, as described above, but saves the cost of the second detector.

An advantageous further development of the method according to the invention with only one detector moving between the two detection positions provides that the single X-ray detector always picks up two X-ray fluoroscopy images of two different spokes including spoke connections in each of the two detection positions before returning to the respective other detection position is moved. Thereby less time is required than if the detector would always run with the recorded in the first detection position spoke including Speichenanbindung in the second detection position and then back to record the next, now in the first detection position located spoke including spoke connection would be moved back.

The object is also achieved by a method according to claim 6. The difference from the solution according to the invention listed in claim 1 is that only one X-ray detector is used for the inventive method according to claim 6, but either the position of the X-ray tube - when only one X-ray tube is used - is changed between a first and a second emission position or two X-ray tubes that are in these two positions. The two fluoroscopic images required for determining the depth of an error in a wheel at different angles of incidence are thus obtained in that two emission positions are present and an immovable recording position of the X-ray detector is present. The fact that the distance between the first emission position and the second emission position is selected such that the same spoke including spoke connection is recorded by the x-ray detector located at the unchanged location ensures that the individual components of the device - the x-ray tube or the x-ray tubes, the Rad and the X-ray detector - are geometrically arranged to each other, that the same spoke is imaged in the two fluoroscopic images. According to the invention, it is provided that after the two fluoroscopic images have been recorded, the wheel is turned so far that a second spoke including spoke connection is in the position which previously occupied the first spoke and subsequently also of the second spoke together with the spoke connection two X-ray fluoroscopy images are created from the two emission positions. Through the repetition of this process, all spokes and their associated Spoke connections illuminated, so that the entire wheel can be checked for errors and their depth. In this second method according to the invention, it is also clear to the person skilled in the art how the geometric relationships between the individual parts of the device described above must be used so that the two fluoroscopic images of each spoke including spoke connection can be used as the basis for determining the depth of a potential error.

The device can in principle have two alternatives: Either two x-ray tubes, which are preferably identical, are used at permanently installed emission positions or only a single x-ray tube is used, which must be moved between these two emission positions for receiving fluoroscopic images of the same spoke including spoke connection.

For the first case with two fixed X-ray tubes, a reduction of the test time compared to the prior art according to the stereo-radiography by n * (t _m - t _s ) + t _g . Namely, the total test time is 2 * n * t _ba + (n-1) * (t _m + t _s ) ⁺ t _a + t _{auS (} where t _{s is} the switching time between the two tubes.

As already stated above for the first method according to the invention, the possibility also exists of saving an essential element in the second method according to the invention; this is an X-ray tube. Then, however, the single X-ray tube has to be traversed, so that there is a loss of time compared to the solution described above with two x-ray tubes around n * (t _g -t _tube ), where t _tube indicates the movement time for changing the position of the X-ray tube. The total test results for this case to 2 * n * t _ba + (nl) * (t _m + t _tube) + t _a + t _AU3. An advantageous development of the invention provides that, after the rotation of the wheel, an X-ray fluoroscopy image is first created in the emission position, in which the preceding X-ray fluoroscopy image of the previously transilluminated spoke together with spoke connection was also created. As a result, the time t _tube for the movement of the x-ray tube from its one position to its other position is saved, in particular in the case of the alternative with only one single x-ray _tube .

The solution described above as a first alternative with two x-ray tubes, wherein the first x-ray tube in the first emissive position and the second x-ray tube are fixed in the second emission position, compared with the second alternative with only a single x-ray tube, the back and forth between the two emission positions has to be moved, the advantage that the recording times of the X-ray images is shorter. By contrast, the second alternative with only a single X-ray tube has the advantage that the costs are lower, since an X-ray tube is saved. In this second alternative, the single X-ray tube is moved between the position of the X-ray fluoroscopy image of the same spoke and spoke connection between the first emission position and the second emission position.

A further advantageous development of the solution principle according to claim 6 provides that the X-ray fluoroscopy system has only one fixed X-ray tube, which has two separate, sufficiently far apart focal spots or a movable focal spot. This allows the change in the position of the focal spot without mechanical movement and without switching the high voltage.

A further advantageous development of the two solution principles according to claim 1 and claim 6 sees suggest that the X-ray fluoroscopy system only have exactly one X-ray tube and exactly one X-ray detector, which are moved between the two emission positions or the two detection positions. As a result, an even greater savings in terms of components is achieved because neither of the X-ray tubes nor the X-ray detectors a second copy is needed, but this is paid for by a further increase in the test time. The smallest possible Gesamtprüfungszeit can be obtained in this alternative, characterized in that the rotation of the wheel always takes place after the position of the respective second fluoroscopic image of a spoke including Speichenanbindung.

A further advantageous embodiment of the invention provides that the wheel is rotated so often that an X-ray fluoroscopic image was created in each detection position and / or in each emission position of each spoke including Speichenanbindung. As a result, all spokes and spoke connections of the wheel are transilluminated and an overall assessment can be made as to whether there is a total error in the tested wheel.

A further advantageous embodiment of the invention provides that the two detection positions and / or emission positions are so far apart that not two adjacent spokes including spoke connection are transilluminated, but at least one spoke is therebetween, of which no X-ray fluoroscopy image is created in this intermediate position. This has the advantage that thereby the angle between the two fluoroscopic images for a spoke including Spichenanbindung be increased, resulting in a better resolution of the depth of a potential error. A further advantageous development of the invention provides that each first recorded X-ray fluoroscopy image of a spoke including spoke connection to be present. is examined by errors and of a spoke including spoke connection no second X-ray fluoroscopy image is taken if no error was found in this X-ray image. This ensures that only in the cases in which in the first recorded X-ray image of a spoke including Speichenanbindung an error is detected, even a second X-ray fluoroscopy image is recorded. For such a two-stage, decision-triggered method, however, a high computing power is required because the determination of whether there is an error must be carried out virtually in real time to decide whether at all still from a second position, an X-ray fluoroscopic image of the spoke including Speichenanbindung must be recorded. However, the total time required for the examination of the entire wheel is reduced, since it may not be necessary to create two X-ray fluoroscopy images for each spoke including the spoke connection.

A further advantageous development of the invention provides that from the two X-ray fluoroscopy images of the two detection positions or emission positions to the spoke including spoke connection on the basis of the geometrical data for the respective detection position or emission position, a depth determination of an approximately found error is calculated. This gives you a complete procedure for tuning the depth of the error from the fluoroscopic images you have taken. It is then possible to decide if a wheel being tested is a reject part or not. This is due to the fact that if the error is too close to the surface, it comes to the surface after finishing and thus the wheel can not be used. A further advantageous embodiment of the invention provides that the depth determination is carried out immediately for a spoke including spoke connection, after the two be present for required fluoroscopic images and the further examination of the wheel is canceled if the depth of a detected error is less than a predetermined limit. This ensures that wheels that have a fault that qualifies the wheel due to its near-surface position as a committee reject part, are no longer tested to the end. This is superfluous, since the mere presence of a single such error is sufficient for classification as a reject part. Thus, the sooner such an error is found, the more the test time of the entire wheel is reduced. However, a high computing power is required for the implementation of such a method, since the determination of the depth position must be carried out virtually under real-time conditions.

A further advantageous embodiment of the invention provides that after the presence of the two X-ray fluoroscopy images of the two detection positions or emission positions to the spoke including Speichenanbindung an evaluation as pseudo-error occurs, if not in both X-ray fluoroscopy each at the same physical position an error is present , As a result, the rate of wrongly classified as reject parts wheels is significantly reduced, whereby pseudo-errors do not lead to the separation.

Further advantages and details of the invention will be explained with reference to the embodiments illustrated in the figures and described below. FIG. 1 shows a first exemplary embodiment with a single embodiment

X-ray tube and two fixed detectors,

Figure 2 shows a second embodiment also with a

X-ray tube and two X-ray detectors, however, which are further apart than in the first embodiment, FIG. 3 shows a third embodiment of the invention with two x-ray tubes and a stationary x-ray detector,

FIG. 4 shows a fourth exemplary embodiment with a stationary x-ray tube and a moving x-ray detector,

Figure 5 shows a fifth embodiment with a moving X-ray tube and a fixed X-ray detector and

6 shows a sixth embodiment with a fixed X-ray tube and a single, sufficiently large fixed X-ray detector.

FIG. 1 shows two phases of a first exemplary embodiment of a method according to the invention for producing two X-ray fluoroscopic images which serve as the basis for determining the depth of an error 6 in a wheel 3. The device for carrying out this first exemplary embodiment, which is illustrated in both FIGS. 1 a and 1 b, contains the following components: There is a single x-ray tube 1, which is held firmly in a spatial location. In addition, the device has two X-ray detectors 7, 9, which are also each held firmly in one place. The X-ray tube 1 emits an X-ray radiation 2 which illuminates active surfaces 7a, 9a of the two X-ray detectors 7, 9. Between the x-ray tube 1 and the two x-ray detectors 7, 9, a wheel 3 to be tested is arranged such that the x-ray radiation 2 passes through two adjacent spokes 4, 5 together with associated spoke connections and thus from these parts of the wheel 3 X-ray fluoroscopy images into the X-ray detectors 7, 9 are generated.

The wheel 3 is arranged on a manipulator (not shown) in such a way that it is perpendicular to the drawing area. ne standing axis of rotation can perform a rotation 16. The rotation 16 of the wheel 3 takes place in a plane which is parallel to the plane of the drawing. The spatial arrangement of the X-ray tube 1, wheel 3 and X-ray detectors 7, 9 is set up for the skilled person without great problems, since he knows such geometrical arrangements from practice and only the above already specified conditions must be met, namely that the X-ray radiation 2 of the X-ray tube 1 two adjacent spokes 4, 5 together with associated Spoke connections of the wheel 3 on the two X-ray detectors 7, 9 is formed.

In the upper figure la, the process is shown in a first stage. In this case, the wheel 3 is in such a position that a first spoke 4 is transilluminated by the X-ray radiation 2 in such a way that it is transilluminated together with its spoke connection such that an X-ray fluoroscopic image is located on it in a first detection position 8 first X-ray detector 7 is recorded. Within the first spoke 4 there are two errors 6 which, due to the predetermined angle of incidence in the X-ray fluoroscopic image, have a certain shape and distance from each other. In addition, the first spoke 4 is rotated clockwise second spoke 5 is arranged so that the X-ray radiation 2 penetrates the X-ray tube 1 together with their Spichenanbindung and the second X-ray detector 9 is arranged in a second detection position 10, so that of this second spoke. 5 together with the spoke connection in the second X-ray detector 9, a transmission image could be recorded.

After an X-ray fluoroscopy image of the first spoke 4 has been recorded by means of the first X-ray detector 7 in the first detection position 8, rotation takes place 16 of the wheel 3 in the clockwise direction until the situation shown in Figure lb is given.

The arrangement of the wheel 3 in Figure lb is such that now the first spoke 4 comes to rest at the point at which the second spoke 5 was arranged in Figure la. In this position, a fluoroscopic image of the first spoke 4 is recorded by means of the second detector 9, which is located in the second detection position 10. Due to the different angle of incidence of the X-ray radiation 2, the shape and relative position of the imaging of the two errors 6 in the first spoke 4 in the second X-ray fluoroscopic image is different than in the first X-ray fluoroscopic image. In FIG. 1b, the two X-ray fluoroscopy images of the first spoke 4 in the two X-ray detectors 7, 9 are shown simultaneously for better illustration.

These two X-ray fluoroscopic images of the same spoke 4 are processed on the basis of the trigonometric functions on the basis of the knowledge of the two imaging geometries for the two detection positions 8, 10 by means of a computer (not shown) and therefrom the depth position of the two errors 6 within the wheel 3, whose geometrical dimensions are also known appraises. Following this, it can be decided either automatically, by specifying a limit value, or by the surgeon, whether the wheel 3 which has just been examined is a reject part. A reject part is present when one of the errors 6 is greater than permissible o- is so close to the surface of the wheel 3 that it would come in the final machining of the wheel 3 too close to the surface. The wheel 3 can then, if it was found as a reject part, easily rejected and melted. The procedure for checking all the spokes 4, 5 of the wheel 3 then proceeds so that from the position in FIG. 1 b in the counterclockwise direction next to the first spoke 5. the further spoke including Spichenanbindung an X-ray fluoroscopy image is recorded by means of the first X-ray detector 7 in the first detection position 8. This corresponds to the situation for the first spoke 4 in FIG. 1a.

Subsequently, the wheel 3 is again subjected to a rotation 16, so that the further spoke, from which an X-ray fluoroscopy image was previously recorded in the first X-ray detector 7, is brought to the position which occupied the first spoke 4 in FIG. In this position, an X-ray fluoroscopy image is then again created by means of the second X-ray detector 9 in the second detection position 10 of this further spoke. This is followed by all steps specified above for the first spoke 4 for determining the depth of any errors 6 present. This is followed by another rotation 16 to the next spoke, etc.

Instead of the above-described procedure, that only one X-ray fluoroscopic image from one spoke and then a rotation 16 of this spoke into the other position - ie according to a transition of FIG. 1 a to FIG. 1 b - is carried out, it is also possible to carry out simultaneously in both X-ray detectors 7, 9 each a fluoroscopic image of two adjacent spokes including Speichenanbindungen be added. This saves time compared with the procedure described in detail above.

Preferably, identical detectors are used, as this brings less computational effort and better comparability of the two X-ray illumination images. However, this is not mandatory.

2 shows a second embodiment of a method according to the invention with a slightly modified device compared to the first embodiment shown in Figure 1 is shown. Here, three phases of the method are shown in Figures 2a, 2b and 2c. In the following Only the differences from the first exemplary embodiment according to FIG. 1 will be discussed in greater detail.

The two X-ray detectors 7, 9 and the associated detection positions 8, 10 are further apart from the first embodiment. The removal of these two detection positions 8, 10 is selected such that the X-ray fluoroscopy images recorded in the two X-ray detectors 7, 9 do not originate from two adjacent spokes, but that between the two transposed spokes 4, 5 there is a third spoke 17, from the one in FIG This step does not create an X-ray fluoroscopic image. Also in this embodiment, the wheel 3 in the first spoke 4 two errors 6. These are recorded in FIG. 2a by the second X-ray detector 9 in the second detection position 10 in an X-ray fluoroscopy image. At the same time, an X-ray fluoroscopic image of the second spoke 5 is taken by the first X-ray detector 7 in the first detection position 8. The second spoke 5 has no errors 6 in the exemplary embodiment.

Following the recording of the two X-ray fluoroscopy images of the first spoke 4 and the second spoke 5, a rotation 16 of the wheel 3 takes place counterclockwise-in other words, as described in FIG. The rotation 16 takes place so far that the third spoke 17 located in FIG. 2a between the two X-ray detectors 7, 9 is moved into the position which the second spoke 5 had assumed in FIG. 2a. As a result, the first spoke 4 moves in the intermediate position, which had taken the third spoke 17 in Figure 2a. In the situation illustrated in FIG. 2b, two X-ray fluoroscopic images are again recorded by means of the first X-ray detector 7 and the second X-ray detector 9. in the first X-ray detector 7, the X-ray fluoroscopic image of the third spoke 17 is taken; No X-ray fluoroscopic image is taken from the first spoke 4 with the errors 6.

Following this, a further rotation 16 of the wheel 3 is carried out counterclockwise until the position of the wheel 3 shown in FIG. 2 c is reached. In this is the first spoke 4 with the errors 6 in the previously occupied in Figure 2b of the third spoke 17 position. Two X-ray fluoroscopy images are taken again, with an X-ray fluoroscopic image being recorded by the first X-ray detector 7 in the first detection position 8 from the first spoke 4. In FIG. 2c, in the second detection position 10, the X-ray fluoroscopy image of the first spoke 4 is shown, so that a better comparison between the two X-ray fluoroscopic images for illustrating the different shape and spacing of the respective errors 6 becomes possible.

The determination of the depth of the error 6 in the wheel 3 is then substantially as already explained above for the first embodiment, it being readily apparent to one skilled in the art that the two X-ray fluoroscopic images of the first spoke 4 are offset against each other - that is the X-ray fluoroscopic image of the second Detection position 10 of Figure 2a and the X-ray fluoroscopy image of the first detection position 8 of Figure 2c.

The advantage of the further distance between the two X-ray detectors 7, 9 relative to the first exemplary embodiment of FIG. 1 is a greater relative "displacement" of the image of the errors 6 due to the larger angles between the two recorded positions. This is reflected in a better resolution of the depth. FIG. 3 shows a third exemplary embodiment of a method according to the invention using a third device. In contrast to the two embodiments of FIGS. 1 and 2, the device according to FIG. 3 has only one single X-ray detector 7 in a detection position 8. However, in order to obtain two X-ray fluoroscopic images of the first spoke 4 at different angles of incidence, the device has two X-ray tubes 1, 13, which are arranged in fixed emission positions 12, 15. Alternatively, a single X-ray tube can be used, which has two separate, sufficiently far apart focal spots or a movable focal spot has the advantage that the change in the position of the focal spot can be done without mechanical movement and without switching the high voltage.

In the first step shown in FIG. 3 a, the first spoke 4 together with the spoke connection is transilluminated by X-radiation 2 emitted by the first X-ray tube 1 in the first emission position 12, and an X-ray fluoroscopy image is recorded by the X-ray detector 7. Here, the two errors 6 in the spoke 4 - as shown - imaged in their contours and their relative distance from each other.

In a second step, a second fluoroscopic image of the first spoke 4 is produced by means of X-radiation 14 emitted by the second X-ray tube 13 in the second emission position 15, as shown in FIG. 3b. The second X-ray fluoroscopic image is again recorded by means of the X-ray detector 7 in the detection position 8. For better clarity, not only the result of X-ray fluoroscopy by means of the second X-ray tube 13 is shown in FIG. 3b (lower two points in the X-ray fluoroscopic image shown in X-ray detector 7), but also the X-ray fluoroscopy image of the first spoke 4 from FIG. 3a with reference to the first X-ray tube 1. As can be clearly seen from the superimposed X-ray fluoroscopic image of FIG. 3b, the position of the two images of the defects 6 and the distance from one another in the two X-ray fluoroscopy images are different. Since the geometric arrangement of the individual components of the device is also known in this exemplary embodiment, the three-dimensional position of the defects 6 within the first spoke 4 can be estimated by means of the triogeometric formulas, as has already been described with reference to FIGS. 1 and 2.

In this embodiment, however, it is not possible to simultaneously create the two required fluoroscopic images, since it can not be clearly determined which two errors 6 due to the X-ray radiation 2 from the first X-ray tube 1 and which two images of the error 6 due to the X-ray radiation 14 from the second X-ray tube 13 have emerged. Preferably, two identical X-ray tubes 1, 13 are used, since this results in a better comparability of the two X-ray fluoroscopic images of each spoke. However, this is not mandatory. To create the additional fluoroscopic images for the other spokes, the wheel 3 is subjected to a rotation 16, which takes place either clockwise or counterclockwise so that the wheel 3 is rotated further around a spoke and then from this next spoke the two fluoroscopic images as in the figures 3a and 3b shown and created above. For those skilled in the art, it will be readily apparent that a rotation 16 of the wheel 3 can not only be up to the adjacent spoke but also to the next but one or even further. However, this does not make sense, since each spoke must be examined and such an approach would only lead to longer paths to the transition from one spoke to the next, which would be given inevitably would result in an extension of the total time of the examination of the wheel 3.

The distance between the two x-ray tubes 1, 13, that is to say the two emission positions 12, 15, could also be selected further from one another, resulting in greater changes in the angle of incidence, which in turn would lead to a more accurate estimate of the depth. 4 shows a fourth inventive embodiment of a method means of a fourth system is shown. FIGS. 4a to 4d show the method and the device at four successive points in time. The fourth exemplary embodiment is very similar to the first exemplary embodiment of FIG. 1, the main difference in the device being that not two fixed detectors 7, 9 are used, but only a single detector 7, which is in two different detection positions 8 , 10 is arranged in order to create the respective second fluoroscopic images of each spoke of the wheel 3 can. The procedure of the method according to the fourth embodiment is as follows:

FIG. 4 a shows the device at a time t = 1. The X-ray radiation 2 emitted by the single X-ray tube 1 passes through the first spoke 4 together with the spoke connection and hits the single X-ray detector 7 in its first detection position 8. In this first detection position 8 a first X-ray fluoroscopic image of the first spoke 4 together with the spoke connection is produced and it follows the fluoroscopic image shown in Figure 4a with the image of the two errors. 6

After the first X-ray fluoroscopic image has been produced, the X-ray detector 7 is moved downwards, as shown in FIG. 4b with the aid of the arrow. In Figure 4b, the device is then shown at a time t = 2, in which the Rad 3 has not changed its position, but the X-ray detector 7 is in its second detection position 10. In this position, an X-ray fluoroscopic image is created by the second spoke 5 together with spoke connection.

5

Subsequently, the wheel 3 is subjected to a rotation 16 in a clockwise direction. The x-ray detector 7 remains fixed at its second detection position 10. This state is shown in FIG. 1c at the time t = 3. After the i o wheel 3 has reached this position, a fluoroscopy image of the first spoke 4 together with spoke connection in the x-ray detector 7 in its second detection position 10 is created by means of the x-ray radiation 2 of the x-ray tube 1. The shape and position of the images of the two errors is 6

15 with respect to the illustration of these two errors 6 shown in Figure 4a different. This essentially corresponds to the conditions as illustrated in FIGS. 1 a and 1 b and described above. The two X-ray fluoroscopic images of the first, made in accordance with FIGS. 4a and 4c

20 spoke 4 are then as already stated above in one

Computer processed so that the depth estimate of the two errors 6 is obtained.

After the second X-ray fluoroscopy image of the first spoke 4 according to FIG. 4c has been taken, the X-ray detector 7 is again moved upward in accordance with the arrow in FIG. 4d until it is again in the first detection position 8 already shown in FIG. 4a. In this position, an X-ray fluoroscopic image is taken of the fourth spoke 11, which is now in the position 30 in which the first spoke 4 in FIG. 4a was located. This is followed by the cycle, which is shown in Figures 4b and 4c for the first spoke 4, analogous to the fourth spoke 11. Thus, also for this fourth spoke 11, two X-ray fluoroscopy images are obtained in the two detection positions 8, 10 and, if in both X-ray fluoroscopy Images of errors would be present - which is not the case here - estimate the depth.

The steps given above for the first spoke 4 and the fourth spoke 11 are then repeated until all spokes have been tested, that is, until the second spoke 5 shown in FIG. 4 has been tested. Thus, all spokes are checked for errors and it can be made a final assessment, whether the currently tested wheel 3 is a reject part or not.

The fifth exemplary embodiment according to the invention shown in FIG. 5 is very similar to the embodiment shown in FIG. The main difference is that the apparatus used does not use two x-ray tubes 1, 13 as in Figure 3, but only a single x-ray tube 1. Otherwise, the construction is similar in that only a single x-ray detector 7 is used in a single detection position 8 and no rotation of the wheel 3 takes place between the creation of the two x-ray fluoroscopic images of a spoke 4.

In order to achieve different angles of incidence, which are necessary for determining the depth of potential errors 6 in a spoke 4, the single X-ray tube 11 is moved between a first emission position 12 shown in FIG. 5a and a second emission position 15 shown in FIG. This is illustrated by the arrow in FIG. 5a.

In FIG. 5 a, the first X-ray fluoroscopy image of the first spoke 4 with the two errors 6 is created by detecting the X-ray radiation 2 of the X-ray tube 1 in the first emission position 12 after passing through the first spoke 4 together with the spoke connection in the X-ray detector 7. After the first X-ray fluoroscopic image has been taken, the X-ray tube 1 is moved along the arrow shown in FIG. 5a to its second emission position 15, which is shown in FIG. 5b. After the x-ray tube 1 has arrived at this second emission position 15, the x-ray radiation 2 is used to scan the first spoke 4 at a different angle of incidence. FIG. 5b shows an X-ray fluoroscopic image in the X-ray detector 7, which is a superimposition of the first X-ray fluoroscopic image shown in FIG. 5a and the second X-ray fluoroscopic image prepared on the basis of the arrangement according to FIG. The two X-ray fluoroscopy images present are then calculated on the basis of the known geometric and physical conditions, as has already been explained with reference to FIG.

After the second X-ray fluoroscopic image of the first spoke 4 according to FIG. 5 b has been recorded, the wheel 3 is rotated so that another spoke of the wheel 3 assumes the position of the first spoke 4. Advantageously, this is one of the two adjacent to the first spoke 4 spokes to minimize the time for the transfer of the wheel 3 in a position in which the next spoke is checked as possible. It does not matter whether the rotation of the wheel 3 takes place clockwise or counterclockwise. After the next spoke to be tested has been positioned, the two fluoroscopic images are taken in the reverse order - that is to say, firstly creating a first X-ray fluoroscopy image according to FIG. 5b and then transferring the X-ray tube 1 to its first emission position 12, where the creation of the second X-ray tube 1 takes place X-ray fluoroscopy image is made according to Figure 5a. These steps are then repeated for all other spokes until the entire wheel 3 has been tested.

The movement of the x-ray tube 1 can take place in the manner of a supported pendulum motion. This means that the X-ray tube 1 is suspended, as it were, from its high-voltage cable (not shown) and oscillates from one to the other position - which of course would be assisted by a mechanical version decoupled from the high-voltage cable. The X-ray tube 1 would then be in their two emission positions 12, 15 each at a stop, so that the main beam direction is not as shown in Figures 5a and 5b in the horizontal, but the respective main beam direction would be slightly rotated from the illustrated main beam directions, respectively in Direction directed to the X-ray detector 7. As a result, an X-ray tube 1 with a smaller opening cone for the X-ray radiation 2 can be used. FIG. 6 shows a sixth exemplary embodiment of a method means of a sixth system according to the invention. The sixth embodiment is very similar to the first embodiment of Figure 1, the main difference in the device being that not two stationary detectors 7, 9 are used, but only a single detector 7 having such a large active area 7a he can detect two spokes 4, 5 velvet spoke connection of the wheel 3. The procedure of the method corresponds exactly to the first method with the difference that the information of two spokes 4, 5 is already present in a fluoroscopic image and the depth position is estimated from this one image in conjunction with the subsequent image. In the first detection position 8, the previously recorded fluoroscopy image of the first spoke 4 is reproduced, which was recorded before the now completed rotation 16 in the position in which now the fourth spoke 11 is located. The fluoroscopy image currently recorded in the illustrated situation is reproduced in the second detection position 10.

In summary, it can be said that all the embodiments according to the invention and the invention in each case On the one hand, as described in detail above, the depth of errors 6 can be determined, and on the other hand, by means of the respective second X-ray fluoroscopic image, the detection rate of pseudo-errors can be drastically reduced. The solution of the second problem results from the fact that two fluoroscopic images are created and only if in each case the potential error is recognizable in both fluoroscopic images is it to be assumed that an actual error exists. On the other hand, if one or more errors are only obtained in one of the two x-ray images of the same spoke, it can be assumed that this is only a pseudo-error. In such a case, there is no reject part because, in fact, there is no real error. If there is a real error, it can be decided on the basis of the information about the depth of this error whether there is still no reject part. If the real error is smaller than the limit value and, for example, in the middle of a thick area of the wheel 3, it is not a reject part; on the other hand, a reject would be present if the real fault were close to the surface. As a result, the rejects are reduced without restricting the quality of the test pieces for the intended operation and requiring considerably more testing time.

LIST OF REFERENCE NUMBERS

first x-ray tube

X-rays

wheel

first spoke

second spoke

error

first X-ray detector

a active surface of the first x-ray detector first detection position

second x-ray detector

a active area of the second x-ray detector 0 second detection position

1 fourth spoke

2 first emission position

3 second x-ray tube

4 x-ray radiation

5 second emission position

6 rotation

7 third spoke

Claims

claims

1. A fluoroscopy method for producing two X-ray fluoroscopy images of at least one spoke (4, 5) including spoke connection of a wheel (3) in an X-ray fluoroscopy system with an X-ray tube (1) and at least one X-ray detector (7, 9) for estimating the depth of potential errors (6) , wherein the X-radiation (2) emitted by the X-ray tube (1) radiates through at least two spokes (4, 5) together with associated spoke connections and the part of the X-radiation (2) which passes through the first spoke (4), the active surface (7a ) of an X-ray detector (7) arranged in a first detection position (8),

and the part of the X-ray radiation (2) passing through the second spoke (5) meets the active surface (7a, 9a) of an X-ray detector (7, 9) arranged in a second detection position (10), the wheel (3) is rotated between the preparation of the first X-ray fluoroscopic image and the creation of the second X-ray fluoroscopic image so that the first spoke (4) is then in the position that previously had the second spoke (5).

2. The method according to claim 1, wherein the X-ray examination system comprises two X-ray detectors (7, 9), which are preferably identical, of which the first X-ray detector (7) in the first detection position (8) and the second X-ray detector (9) in the second detection position (10).

3. The method according to claim 1, wherein only one X-ray detector (7) is used, the active surface (7a) is so large that at least two irradiated spokes (4, 5) including spoke connection are detected simultaneously.

The method according to claim 1, wherein the X-ray transillumination system has only one X-ray detector (7) which is moved between the generation of the two X-ray fluoroscopic images between the first detection position (8) and the second detection position (10).

Method according to claim 4, wherein in each of the two detection positions (8, 10) the X-ray detector (7) always picks up two X-ray fluoroscopy images of two different spokes (4, 5) together with spokes connections, before moving them back into the respective other detection position (10, 10). 8) is moved.

A fluoroscopy method for producing two X-ray fluoroscopy images of at least one spoke (4, 5) including a spokes connection of a wheel (3) in an X-ray fluoroscopy system comprising an X-ray detector (7) and at least one X-ray tube (1, 13),

wherein a first X-ray fluoroscopy image of the first spoke (4) including spoke connection by means of an X-ray tube (1) in a first emission position (12) it is placed and then a second X-ray fluoroscopy of the first spoke (4) including spoke connection by means of an X-ray tube (13) in a second Emission position (15) is created,

wherein the distance between the first emission position (12) and the second emission position (15) is selected such that the same spoke (4, 5) and spoke connection are detected by the active part (7a) of the X-ray detector (7) located at the unchanged location, wherein then the wheel (3) is rotated so far that a second spoke (5) including spoke connection of the wheel (3) is in the position previously the first spoke (4) including spoke connection has occupied

wherein, subsequently, two X-ray fluoroscopic images of the two emission positions (12, 15) are produced by the second spoke (5) together with the spoke connection.

7. The method according to claim 6, wherein after the rotation of the wheel (3) first an X-ray fluoroscopy image in the emission position (12, 15) is created, in which the previous X-ray fluoroscopy image of the previously transposed spoke (4, 5) including spoke connection was created.

8. The method according to claim 6 or 7, wherein the X-ray fluoroscopy system comprises two X-ray tubes (1, 13), which are preferably identical, of which the first X-ray tube (1) in the first emission position (12) and the second X-ray tube (13) in the second emission position (15).

9. The method according to claim 6 or 7, wherein the X-ray fluoroscopy system has only one X-ray tube (1), which between the preparation of the X-ray fluoroscopic images of the same spoke (4, 5) including spoke connection between the first emission position (12) and the second emission position (15 ) is moved.

10. The method according to claim 6 or 7, wherein the X-ray transilluminator has only one fixed X-ray tube having two separate, sufficiently far apart focal spots or a movable focal spot.

11. The method according to any one of the preceding claims without claim 2 and 7, wherein the X-ray only one X-ray tube (1) and exactly one X-ray detector (7), which are moved between the two emission positions (12, 15) and the two detection positions (8, 10).

12. The method according to claim 11, wherein the rotation of the wheel (3) always takes place after the creation of the respective second fluoroscopic image of a spoke (4, 5) together with Speichenenzindung.

13. The method as claimed in one of the preceding claims, wherein the wheel (3) is turned so often that an X-ray fluoroscopy image of each spoke (4, 5) including the spoke connection is present in each detection position (8, 10) and / or in each emission position (12, 15) was created.

14. The method according to any one of the preceding claims, wherein the two detection positions (8, 10) and / or emission positions (12, 15) are so far apart that not two adjacent spokes (4, 5) are transilluminated including spoke connection, but at least one Spoke is in between, is created by the no fluoroscopic image in this intermediate position.

15. The method according to any one of the preceding claims, wherein each first recorded X-ray fluoroscopy image of a spoke (4, 5) including spoke connection is examined for the presence of errors and of a spoke (4, 5) including spoke connection no second X-ray fluoroscopy image is taken, if not a fault was found in this fluoroscopic image.

16. The method according to any one of the preceding claims, wherein from the two X-ray fluoroscopic images of Both detection positions (8, 10) and emission positions (12, 15) to the spoke (4, 5) including spoke connection based on the geometric data for the respective detection position (8, 10) or emission position (12, 15) the depth of an approximated error is calculated.

17. The method according to claim 16, wherein the depth determination is carried out immediately for a spoke (4, 5) including spoke connection after the two X-ray fluoroscopy images required for this exist and the further examination of the wheel (3) is stopped if the depth of the found Error is less than a given limit.

18. The method according to any one of the preceding claims, wherein after the presence of the two X-ray fluoroscopy images of the two detection positions (8, 10) or E- missionspositionen (12, 15) to the spoke (4, 5) including spoke connection after the presence of two X-ray fluoroscopy of the two Detection positions to the spoke including Spichenanbindung a valuation as a pseudo-error takes place, if not in both X-ray fluoroscopy each an error in physically same position is present.