WO2003009245A1 - Method for the recognition of the switching state of pipe systems - Google Patents

Abstract

The invention relates to a device and a method for the recognition of the switching state of a pipe system with at least one switching element which may be switched into various line configurations, in particular in a brewery plant. In order to be able to simply determine the switching state of a switching element, the switching state of the switching element is optically recorded and evaluated by means of a camera.

Description

 Method for recognizing the switching status of piping systems

The invention relates to a method for recognizing the switching state of a piping system which can be switched to at least one switching element in different line configurations, in particular in a brewery system.

As is known, in breweries the system components, e.g. Mash container, wort cooker, lauter tun, fermentation tanks and the like are connected to each other by pipelines. Depending on the operating mode of the system, there is a need to switch the pipes in different constellations, i.e. to connect them in different ways, which is usually done by switching suitable switching elements in the lines. For this purpose, there are especially so-called Known valve nodes at which different lines intersect and which can be switched to different constellations by appropriately switching switching valves.

Especially in fermentation tanks, so-called. Panels used. Such a panel generally comprises a front panel with connections and manually displaceable swivel bends, the swivel bends being implemented, depending on the process control, and thus connecting different pipelines to one another suitably for the intended purpose. For correct process control, which is nowadays generally carried out by computer, it is necessary to determine the switching status of the piping system, i.e. that is, to know the piping constellation, so that it is ensured that when initiating or carrying out a certain process, the pipes are correctly connected to each other in the correct position.

In order to be able to check and monitor this, the position of the swivel bends was evaluated in the prior art with initiators which, depending on the position, give an electrical signal to the control system (PLC). The valves also have corresponding detectors, which transmit signals to the control system about their switching status, so that the pipeline system's pipeline system can then be determined by evaluating these signals. However, monitoring the valves and monitoring the position of the swivel bends with initiators means that every single valve or swivel bend must be connected to the controller, which in turn must have a large number of digital inputs in order to process the corresponding signals can. The effort for this is therefore considerable. The invention is based on the object of specifying a method and a device with which the switching state of a pipeline system, in particular in a brewery system, is simpler.

According to the invention, this object is achieved in that the switching state of the switching element is optically recorded and evaluated with a camera.

The optical monitoring of the switching elements allows the respective switching constellation of the piping system to be recognized in a simple manner and thus saves, in particular, if, as is generally the case, a number of switching elements determine the switching state of the switching system, the wiring of each individual switching element with the control , All information is forwarded from the camera to the controller. The detection is then carried out by appropriate image processing, which is much easier than if each individual switching element with its initiators has to be connected to the control.

In an advantageous embodiment of the method, the detection and evaluation of the switching state of the switching element comprises the substeps of recording a calibration image with the switching element, determining the image coordinates of the calibration image with the switching element with reference to at least one marking point in the image and storing the determined calibration image data, recording a current one Image with the switching element and the marking point and generation of corresponding image data and the comparison of the scanned image data with stored calibration image data.

In this preferred embodiment of the method, a calibration image is therefore first created using the switching element. The calibration image can include the surroundings of the switching element. In this case, a marking point is formed in the vicinity of the switching element, which can either be defined as a high-contrast point on the image or can be designed as a glued-on or specially applied marking. With reference to this marking, the image coordinates and the associated image data of the calibration image can then be defined and stored with the switching element.

So you have a calibrated image in memory for a certain switching state of the switching element with its surroundings. If a current image is now recorded, an adjustment can be carried out via the marking point in that the image coordinates can be determined in accordance with the calibration image by recognizing the marking point even in the case of somewhat different camera positions. One can then find the area of the switching element again without complicated fine adjustment in the image and compare it with the stored calibration image and draw conclusions about the switching state from this comparison.

This coordination of the image coordinates with the aid of the marking point considerably simplifies the use of the system, because it is therefore not important that the camera always records from exactly the same position.

The marking points are attached in such a way that they are also recorded in a picture of the switching element that is usually recorded. For example, they can be designed as concentric, high-contrast circles (black / white). There are preferably two position marks. The camera with the image processing device can easily recognize and evaluate these marks. However, as mentioned, it is also possible not to arrange separate position marks, but to define a prominent position on the image to be recorded, for example the edge in the case of a panel.

In a further advantageous embodiment, an area of the switching element is defined in the calibration image as a sensitive area with corresponding image coordinates, different area image data representing the different switching states of the switching element are stored for the sensitive area, and the recorded image is stored in the sensitive areas with the stored area image data compared. With this measure it is possible, after recognizing the markings and thereby adjusting the currently recorded image, to immediately carry out the image comparison in the sensitive areas, i.e. in the areas in which, by changing the switching state of the switching element, e.g. moving a swivel bend or changing a valve , a change has occurred. This increases the processing speed because less image data, namely only those from the sensitive areas, have to be compared with the data of the corresponding stored areas. The optical detection of the images can take the form of a brightness measurement, the switching state of the switching element being recognizable by simply comparing the gray level values of the recorded image with the gray values of the previously stored calibration image, and the line configuration of the entire system can thus also be determined easily.

As already explained, the critical areas can be defined, for example, in the area as points or small circular areas in which the swivel arcs are implemented, and they can also be defined for valves in the area of the handle with which the valves can be switched over by hand. If valves do not allow their switching status to be easily recognized from the outside, it is also possible to mark the parts of the valve that are moving when they are switched, for example with colored markings or pointers, and then there to identify the sensitive areas that can then be easily identified define.

It is also possible to define critical areas, for example on a panel, which are located at locations where a medium can escape from the pipelines. It can also be used to make statements about the tightness of the lines.

A device for carrying out the method is characterized in that it comprises a camera for optically recording the switching element and an image processing device which evaluates the recorded image. The image processing device preferably comprises a unit for defining and storing the image coordinates with associated image data of the calibration image and a comparison unit for comparing scanned current image data with the stored image data of the calibration image at the correlated image coordinates.

Further advantageous configurations result from the further dependent claims.

The invention is explained in more detail below with reference to the drawing. It shows:

FIG. 1 shows a view of a panel with switching elements,

FIG. 2 a swivel arch, FIG. 3 shows a schematic representation of the overall structure of the device according to the invention,

Figure 4 is a recorded image according to the inventive method

Panels of FIG. 1,

FIG. 5 shows a flow chart to explain the method steps of the method according to the invention and

Figure 6 fermentation tanks in a fermentation cellar with valve nodes.

In Figure 1 is a so-called. Panel or ClP panel 1 shown how it is used in breweries. It essentially consists of a front plate into which lines 6, which are not shown from the rear in FIG. 1 but indicated in FIG. 3, open. The pipelines end in connections 12, which can be closed by manually operated flap valves 10 (or also electrically operated). The individual connections can be connected to one another in different ways by swivel bends 8, which can be implemented by hand, so that depending on the arrangement of the swivel bends and position of the valves 10, different line configurations of the entire pipeline system result. The valves 10 and the swivel bends 8 thus represent switching elements on the basis of whose position the switching state of the system can be seen.

In the exemplary embodiment shown, the valve position can be detected at the position of the handles 11, while the position of the swivel bends results from their different orientations, depending on which connections 12 are connected to one another. A converted sheet is indicated by a dashed line in FIG. 1.

Neuralgic areas marked by black points 14a, 14b and 14c are defined on this panel. In addition, marking points 13 each are provided on the front plate by three concentric circles. The circles are high-contrast, for example realized in black and white. FIG. 2 again shows separately a swivel arch 8, as can be used in the panel 1 by repositioning it for the optional connection of different connections 12. In order to be able to carry out a reliable and safe process control, it is necessary to record the switching status of the individual valves 10 and the arrangement of the swivel bends 8, ie the pipeline constellation.

The camera 2 shown schematically in FIG. 3 is used for this purpose, which is arranged in front of the panel and can record an image of the entire panel 1. The camera 2 is, for example, a CCD camera, which is arranged fixedly opposite the panel 1 and is connected to an image processing device 4, which in turn can be connected to the process control, not shown, of the entire system, e.g. a brewery system.

In order to ensure uniform lighting even at night, a lamp 5 can also be provided which always illuminates the panel uniformly, so that regardless of day and night fluctuations, the brightness conditions on the panel are essentially the same.

Figure 4 now shows an image, e.g. can be recorded by the camera 2 for the panel shown in Figure 1. The locations shown as black dots 14a, 14b and 14c represent critical areas 14. These critical areas serve to evaluate the image. They are arranged at the points where, depending on the piping constellation, a different situation arises, where it can be stated whether a swivel bend 8 is set at this position or not or whether a valve 10 is open or not. For example, there is a sensitive area 14a between two connections 12a and 12b and a sensitive area 14c between two connections 12c and 12d. Finally, there are sensitive areas 14b in the area of the ends of the handles 11 of the valves 10.

The method according to the invention will now be further explained with reference to the flow diagram of FIG. 5 and the illustration of FIGS. 1 and 4.

First of all, it is necessary for the camera 2 to record a calibration image of the panel with the switching elements. The neuralgic areas with their image coordinates with respect to the markings 13 are defined in the calibration image. The critical areas are selected so that when the switching states change, there is also changed image data, in other words, it is determined which points or areas must be monitored in order to determine the switching state of the individual valves or the position recognizable on the swivel arches 8. The calibration image is then stored, the image data recognizing the corresponding switching states being stored in each case at the image coordinates of the sensitive areas. A calibration image has thus been created that captures the different switching constellations. This image or these images are then saved. This process is designated in the flowchart in FIG. 5 with step SO.

It is generally carried out once, so it does not have to be carried out every time the system is restarted.

In order to now determine current switching states, steps S1 to S5 (FIG. 5) are carried out.

During operation, the camera 2 takes a current picture of the panel. For evaluation, the image coordinates of the recorded image must now be defined in step 2, so that the image data at the critical points can be compared with the stored image data. For this purpose, the image processing device recognizes the position marks 13 and then determines the relative image coordinates with reference to these marks. This results in the possibility, independently of the camera position, of carrying out a comparison with the stored image data of the calibration image at the correlated image coordinates. A complex adjustment of the camera is not necessary.

In steps S3 and S4, the image data are then generated in the image processing device at the coordinates of the sensitive areas 14a and 14b and 14c. This data is then compared with the calibration image data stored for these critical areas. If, for example, the gray value of the neuralgic area 14a with the coordinates Xi yi approximately corresponds to the gray value of the previously stored neuralgic area with the coordinates Xi y ^, the image processing device can output a signal which indicates that a swivel arc 8 is set at this point. In contrast, a comparison of the gray value at the neuralgic area 14c with the coordinates x ₂ y ₂ with the gray value stored at the image coordinate x ₂ , y _{2 will} result in a clear difference, so that the image processing device outputs a signal that indicates that between no swivel bend is set at the connections 12c and 12d. If, for example, the gray value at the neuralgic point 14b with the coordinates x ₃ y3 is further compared with the stored gray value at the position x ₃ y ₃ , the image processing device will determine that the gray values match and output a signal which indicates that the valve is open. Of course, a corresponding fluctuation range can be specified for the gray values or also for the brightness values, within which the signal must lie in order to infer a certain state. It is also possible to determine color values instead of gray value detection. In this case, the marking points are highlighted, for example, by a characteristic coloring.

The signals of the image processing device 4 are then passed on to the controller (not shown) and used there for further process control. This method can now be carried out continuously or at certain intervals, so that continuous monitoring or monitoring from time to time is possible. The signal can e.g. also be used to prevent certain processes from starting if the constellation captured by the camera does not correspond to the constellation required for a specific process step.

The method according to the invention can also be used, for example, to monitor the tightness of the panel. A leaky pipe also represents a pipe constellation that can be detected by this system. The image coordinates can then be entered as critical areas, which are arranged at locations at which a medium could escape from the pipelines. If the pipeline panel is leaking, there are differences between the image data of two successive images at the corresponding points, so that the image processing device can then output a signal if there is a leak.

A further application of the invention is shown in FIG. Three fermentation tanks 17a, 17b and 17c are shown here, the fermentation tank 17a just being filled, the fermentation tank 17b being emptied and the fermentation tank 17c being cleaned. The different processes are automatically controlled. The pipes 9 from the fermentation tanks run over a so-called. Valve node at which electrically operated double-seat valves control the switching constellation of the entire system. Depending on the process being run, different lines are connected to each other. The double-seat valves 15 have a valve head 16 which, on the basis of a marking, such as a position flag 18, shows the switching state. The flag 18 rotates, for example, when the valve is switched. The switching status can also be marked by changing the color or a pointer. To carry out the method according to the invention, a camera is directed onto this valve node, which then enables the switching state to be identified in accordance with the exemplary embodiment described above. Corresponding circles can also be attached to the lines as markings. It is also possible to use the contour or a specific crossing point as a marker in the captured image.

The switching states and thus the piping constellation can be continuously recognized and monitored by the method and the device according to the invention. Since only a connection from the image processing device to the system control is necessary, a large number of digital inputs are saved, which are required in the prior art to connect lines coming from each individual switching element. All information can be forwarded directly from the image processing device to the control. This optical monitoring entails an additional security mechanism. The evaluation of the position marks 13 before the image analysis ensures that the image analysis always starts from the correct coordinates. The evaluation becomes invariant against shift in the image. This also eliminates the need to fine-tune the camera.

Claims

claims 1. A method for recognizing the switching state of a piping system which can be switched to at least one switching element in different line configurations, in particular in a brewery system, characterized in that the switching state of the switching element (8, 10, 15) is optically recorded and evaluated with a camera (2). 2. The method according to claim 1, characterized in that the detection and evaluation of the switching state of the switching element comprises the following substeps: - recording a calibration image with the switching element, Determining the image coordinates of the calibration image with the switching element with reference to at least one marking point in the image and storing the associated calibration image data, Recording a current image with the switching element and the marking point (13) and generating corresponding image data, - Compare the scanned image data with the stored calibration image data. 3. The method according to claim 2, characterized in that at least two marking points (13) are provided. 4. The method according to claim 2 or 3, characterized in that the marking point is created by attaching a position mark comprising concentric circles in the surrounding area of the switching element to be recorded. 5. The method according to claim 2, characterized in that as a marking point an optically distinct from the area, z. an edge of a line or the like is used. 6. The method according to any one of claims 2 to 5, characterized in that the area of the switching element is defined as a sensitive area with corresponding image coordinates in the calibration image, that different area image data representing the different switching states of the switching element are stored for the sensitive area and that the recorded image at the sensitive areas is compared with the stored area image data. 7. The method according to any one of claims 1 to 6, characterized in that a brightness or color measurement is carried out during scanning and different grayscale levels or color values are used as image data. 8. The method according to any one of claims 1 to 7, characterized in that the switching element is a valve and / or a swivel bend in a pipe panel. 9. The method according to any one of claims 1 to 7, characterized in that the switching element is a valve, in particular a double-seat valve of a valve node. 10. The device for performing the method according to claim 1, characterized by a camera (2) for optically recording the switching element and an image processing device (4) which evaluates the recorded image. 11. The device according to claim 10, characterized in that the image processing device (4) comprises: a unit for defining and storing the image coordinates with associated calibration image data, and a comparison unit for comparing sampled current image data with the stored calibration image data at the correlated image coordinates. 12. The apparatus according to claim 11, characterized in that it is assigned to a ClP panel, which comprises a front panel and a plurality of manually displaceable swivel bends, for detecting the switching state of the switching elements such as swivel bends (8) and flap valves (10). 13. The apparatus according to claim 12, characterized in that on the ClP panel at least one position mark (13), preferably with concentric circles, is attached.