Method for keeping a sensor assembly clean and for cleaning a sensor assembly having at least one contactlessly operating sensor, and sensor assembly

Abstract

The invention relates to a method for keeping a sensor assembly clean and for cleaning a sensor assembly (200) having at least one contactlessly operating sensor (210) for carrying out a measurement, said method having the following steps: • providing a sensor assembly (200) having at least one contactlessly operating sensor (210) which has a portion (220) for outputting and / or receiving a measurement signal; • detecting the degree of soiling of the sensor portion; • determining whether the degree of soiling is below or above a soiling threshold value; • dispensing, at least while carrying out the measurement, an air flow over the sensor portion at a first preset pressure and a first preset volumetric flow rate as long as the degree of soiling is below the soiling threshold value; • dispensing an air flow over the sensor portion at a second preset pressure and a second preset volumetric flow rate and dispensing a water jet, together with the process of dispensing the air flow, at a third preset pressure and a third preset volumetric flow rate, in each case for a first time interval, as soon as the degree of soiling is above the soiling threshold value, • stopping the water jet but continuing to dispense the air flow over the sensor portion at the second preset pressure or a fourth preset pressure and at the second preset volumetric flow rate or a fourth volumetric flow rate for a second time interval, and • detecting the degree of soiling of the sensor portion.

Description

[0001] Method for keeping clean and cleaning a sensor arrangement with at least one non-contact operating sensor and a sensor arrangement

[0002] The invention relates to a method for keeping clean and cleaning a sensor arrangement with at least one non-contact operating sensor and a sensor arrangement.

[0003] When a tunnel is driven using a tunnel boring machine, rings made of reinforced concrete segments (tunnel lining segments) are used, among other things, to support the tunnel. These are positioned, for example, under a shield of the tunnel boring machine or directly against the tunnel wall using an erector. For this purpose, the erector includes, for example, a manipulator that can be moved axially, radially, and tangentially relative to the base of the erector.

[0004] Manipulators of this kind are well-known from robotics. They represent, for example, the movable part of the robot and enable physical interaction with the environment or with objects within it. The manipulator performs tasks or actions using specialized tools. These tools are positioned in space via actuators. Furthermore, measurements are taken that either facilitate positioning or manipulation and / or collect data for analysis. The manipulator typically includes load-bearing components that are movably connected to each other via the actuators.

[0005] To position at least one tunnel lining segment, a picking tool is attached to the manipulator. This tool can be, for example, a gripping tool and / or a suction tool. The tool or the manipulator itself is moved by actuators. The gripping tools, for example, grasp a pin attached to the tunnel lining segment. The suction tools, in turn, directly pick up the tunnel lining segment.

[0006] The tunnel lining segments are fed to a receiving point in a defined sequence via a feeding unit (segment feeder). At the receiving point, the tunnel lining segment is picked up by the manipulator tool, lifted, and moved to its respective placement location. Actuators are provided for this purpose, enabling the corresponding rotational, linear, and / or tilting movements of the tool.

[0007] The movements of the manipulator, or rather its tool, are currently controlled by an operator. The individual actuators of the erector or manipulator are controlled, preferably remotely, via corresponding control elements. This is a dangerous activity, as the operator must be within the erector's vicinity to be able to position the tunnel lining segments visually. Furthermore, due to its many degrees of freedom, various actuators, and the necessary precision for placing the tunnel lining segments, the movement speed of the erector / manipulator is reduced to ensure the safe execution of the complex process of picking up, moving, and placing the segments, possibly with the assistance of other personnel on site.

[0008] The erector is a type of specialized crane whose tool can be moved, for example, hydraulically via axes in radial, tangential, and axial directions relative to the machine axis of the tunnel boring machine. Depending on the design, the radial axis itself can be, for example, a telescopic unit or a parallel linkage. The tool, also called the erector head, is attached to the manipulator to hold the tunnel lining segments. The erector head has a receiving mechanism to lift and move the respective tunnel lining segment. For fine-tuning, the position of the erector head can be moved around hydraulically driven rotary axes in the form of rolling / swiveling, pitching / tilting, and yawing / rotating. Generally, the actuators move the tool relative to the machine axis of the tunnel boring machine.The tool is moved, for example, axially along the machine axis, radially from the machine axis, and rotating around the machine axis. This can also occur along axes parallel to the machine axis. Further rotational movements can also occur around axes radial to the machine axis of the tunnel boring machine.

[0009] A tunnel lining ring consists of several tunnel lining segments. The number of segments varies depending on the ring design. The tangential position of the individual segments within the ring is predetermined by the tunnel lining design. Depending on the construction method, a ring can consist of straight segments where the longitudinal joints are perpendicular to the ring joints, or of a combination of, for example, trapezoidal, semi-trapezoidal, straight tunnel lining segments and / or other shapes. Tunnel curves are achieved by rotating the segments relative to each other, resulting in slightly different axial lengths.

[0010] Openings for mounting aids, known as dowels, may be provided on the segments at their contact surfaces along the longitudinal and / or annular joints. The dowels are inserted into the designated openings in the tunnel lining segment. Once the segment has reached its correct placement position, the mounting aids are inserted into the designated openings of the already positioned segments. The erector operator makes a fine adjustment to the tool alignment to ensure the mounting aids are inserted correctly. The segment is then positioned accordingly.

[0011] After the tunnel boring machine (TBM) has completed a stroke (e.g., 1.2 m), the lining process begins. The erector picks up the first tunnel lining segment from the segment feeder. Simultaneously, the TBM's jacking jacks, located in the area where the lining segment is to be placed, are retracted to clear the area for the segment to be inserted. Once the lining segment is in position, the jacking jacks are extended again to press the segment into its final position against the previous lining ring. This process also compresses the edge seals of the lining segments to the required dimension. The erector's tool is then released and retracted to the pickup position to receive the next lining segment. At the same time, the corresponding jacking jacks are retracted, and the process is repeated until the entire ring has been placed.With the insertion of the keystone into the tunnel lining segment ring, the seals in the longitudinal joints are also compressed, the ring is closed, and the tunnel lining segments are brought into their final position, if necessary by final pressing of the tunnel lining segments by the jacking jacks. After completion of the lining, the annular space between the tunnel wall and the finished lining ring is then filled at a later stage, for example, with grout.

[0012] Since, as already explained, this is a not entirely safe and strenuous activity, which, due to the complexity of the movement possibilities, must also be carried out at reduced speed, there have long been efforts to automate the process of placing the tunnel lining segments for the construction of the tunnel lining ring. Several approaches for this are already known from the prior art; see, among others, FR 2,745,327, CN104747213, JPH08-296400, WO2018065726, WÖ2021136837A1.

[0013] Since the tunnel lining segments are subject to manufacturing tolerances, and the excavated tunnel wall against which the tunnel lining segments are placed also has dimensional tolerances, it is necessary to record the exact position of the tunnel lining segments already in place, or of the complete tunnel lining rings, within the excavated space. Furthermore, it is necessary to adjust and align the target position of each tunnel lining segment with the segments already in place during placement. For this purpose, known technologies include CCD cameras, contact sensors, laser profilometers, radar, and ultrasound. However, these methods are sometimes very inaccurate due to environmental conditions during excavation with the tunnel boring machine, such as moisture, dust, dirt, and surrounding components.

[0014] It has been found that the quality of the placement of the tunnel segments decreases when the sensors become dirty, even leading to dysfunction.

[0015] A cleaning system for such sensors is known from CN 115653611 A. For monitoring the tools of a tunnel boring machine's cutterhead, a dual camera for visible and infrared light with a light source behind the cutterhead is provided. The camera and the light source are arranged in a protective box with openings for the lenses. A grid is positioned over the openings. To prevent lens contamination, a water and air cleaning system is provided in the lens area. This system consists of multiple central water nozzles for delivering water from a water cleaning pipeline onto the two lenses and the light source, and two outer nozzles for delivering air from an air drying pipeline, one onto each lens. This enables real-time lens cleaning. The lenses are cleaned with the delivered water and then dried with the delivered air. A significant amount of water is introduced, as required by the system's design.It has been found that the cleaning results achieved with this arrangement are only partially satisfactory. Improvements are therefore necessary.

[0016] A similar approach is disclosed in DE102019216599A1. This document discloses a sensor device, intended in particular for use in washing machines, and a method for its operation. The sensor device consists of a housing with a sensor chamber through which the liquid to be analyzed is passed. At least one sensor is installed in this chamber, measuring certain properties of the liquid, such as turbidity, conductivity, or chemical composition. To protect the sensor surface from contamination and to maintain its functionality, a special nozzle device is integrated. This device can direct jets of air or water onto the sensor surface for cleaning. The associated method provides for the sensor surface to be cleaned regularly or as needed by the nozzle device. This can be done automatically, for example, when a specific type of contamination is detected or at predetermined intervals.The cleaning process is carried out in such a way that the sensor function is not interrupted as much as possible.

[0017] The object of the invention is therefore to provide a continuous and sensor-controlled operation of the tunnel lining segment installation that is not affected by the aforementioned disadvantages, so that automated installation of the tunnel lining segments is continuously possible.

[0018] With regard to the sensor arrangement according to the invention, the problem is solved by the combination of features of claim 1. Further advantageous embodiments are defined by dependent claims 2 to 7. Furthermore, the problem according to the invention with regard to the method is solved by the combination of features of claim 8. Further advantageous embodiments are defined by dependent claims 9 to 11.

[0019] The inventive method for keeping and cleaning a sensor arrangement with at least one non-contact operating sensor for carrying out a measurement comprises the following steps:

[0020] 1. Providing a sensor arrangement with at least one non-contact sensor having a section for emitting and / or receiving a measurement signal,

[0021] 2. Providing at least one opening connected to a supply line for the delivery of at least one airflow over and / or onto the section,

[0022] 3. Providing at least one opening connected to a supply line for delivering at least one jet of water onto the section of the sensor arrangement,

[0023] 4. Providing control valves for adjusting pressures and flow rates at the openings,

[0024] 5. Providing a computer-based control system for adjusting pressures and flow rates at the openings,

[0025] 6. Determining the degree of contamination of the sensor section, either automatically or manually,

[0026] 7. Determine whether the pollution level is below or above a pollution limit, either automatically or manually; 8. Deliver an airflow over the sensor section at least during the measurement process with a first preset pressure and a first preset volume flow rate, as long as the pollution level is below the pollution limit.

[0027] 9. Dispensing an airflow over the sensor section at a second preset pressure and a second preset volume flow rate, and dispensing a water jet together with the airflow at a third preset pressure and a third preset volume flow rate, both for a first time interval, as soon as the degree of contamination exceeds the contamination limit.

[0028] 10. Stop the water jet but continue to release the airflow over the sensor section at the second or a fourth preset pressure and at the second preset or a fourth volume flow for a second time interval,

[0029] 11. Determining the degree of contamination of the sensor section,

[0030] 12. Repeat the procedure from step 7.

[0031] Surprisingly, it has been shown that directing the airflow over the sensor or its section significantly reduces contamination of the sensor or its section in a simple manner. This creates a kind of air curtain that greatly reduces the impact and settlement of dust, water droplets, or slurry / bentonite suspension on the sensor, thus also significantly reducing the frequency of cleaning and interrupting the installation of the tunnel lining segments. This applies both to measurement operations and to the breaks between measurements.

[0032] Furthermore, it has surprisingly been shown that by combining compressed air jets and water jets, the cleaning effect can be increased while at the same time significantly reducing the amount of water required.

[0033] A further aspect of the invention provides that a nozzle, preferably at least two parallel point jet nozzles or at least one flat jet nozzle, is provided as the opening for releasing at least one air stream. A further aspect of the invention provides that a nozzle, preferably a fan nozzle, cone nozzle, or hollow cone nozzle, is provided as the opening for releasing at least one water jet. This improves the effectiveness of the delivery for cleaning and maintenance.

[0034] Another teaching of the invention provides that the first volume flow of the air stream is reduced to 12 to 16 m³ in the event of contamination with a sludge or bentonite suspension during the measurement operation. 3 / h distributed across the number of nozzles at 0.5 to 2 bar, preferably 13 to 15 m 3 / h at 0.75 to 1.5 bar, particularly preferably 14 m 3 The flow rate is set to / h at 1 bar. This ensures optimal cleanliness.

[0035] Another teaching of the invention provides that the release of an airflow over the section of the sensor during the measurement is continuous or pulsed.

[0036] Another teaching of the invention provides that the second volume flow of the airflow is reduced to 20 to 40 m³ in the event of contamination with a mud or bentonite suspension. 3 The flow rate is distributed across the number of nozzles at a pressure of 5 to 6 bar. This ensures optimal cleaning performance.

[0037] A further aspect of the invention provides that the third volume flow of the water jet, when contaminated with a sludge or bentonite suspension, is set to 0.8 to 3 l / min distributed across the number of nozzles at 0.5 to 8 bar, preferably 1.1 to 2 l / min at 1 to 7 bar, and particularly preferably 1.6 to 1.8 l / min at 6 bar. This achieves optimal cleaning performance.

[0038] A further teaching of the invention provides that the inventive method is implemented during a method for the automated installation of at least one tunnel lining segment of a tunnel lining ring for lining a tunnel section driven by a tunnel boring machine with an installation device described below, in which a manipulator equipped with at least one tool for picking up, holding and placing the at least one tunnel lining segment is provided, and which is provided in a tunnel boring machine.

[0039] • wherein the at least one tool with at least one actuator is moved in a radial, tangential and / or axial direction with respect to the machine axis of the tunnel boring machine in the space of the tunnel section constructed by the tunnel boring machine,

[0040] • wherein at least one tool position sensor provided on the manipulator and / or tool is used to detect the actual position and orientation of the tool in the space of the tunnel section,

[0041] • wherein at least one tunnel lining segment sensor, provided on the manipulator and / or tool, detects the actual position and / or actual location of at least one section of at least one already arranged tunnel lining segment, and / or wherein the at least one tunnel lining segment sensor detects the actual position and / or actual location of the tunnel lining segment to be placed,

[0042] • wherein at least one control system is provided which accesses installation data of the tunnel lining segments as well as the measurement data of the at least one tool position sensor and the at least one tunnel lining segment sensor,

[0043] • wherein the at least one controller, based on the installation data and measurement data, controls the at least one actuator and the at least one tool, such that the tool with the tunnel lining segment is moved from its respective receiving position to its respective target placement position and the tunnel lining segment is aligned to the actual placement position based on the measurement data of the tunnel lining segment sensor and arranged against at least one already placed tunnel lining segment of a tunnel lining ring.

[0044] It is advantageous that at least two tunnel expansion segment sensors are provided as part of a sensor arrangement according to the invention, wherein the tunnel expansion segment sensor is preferably a time-of-flight camera.

[0045] The sensor arrangement according to the invention provides a sensor arrangement with at least one non-contact operating sensor, which has a section for emitting and / or receiving a measurement signal, with at least one opening for emitting at least one airflow over and / or onto the section and at least one opening for emitting at least one water jet onto the section, characterized in that a control is provided which switches the at least one opening for emitting the at least one airflow and / or the at least one opening for emitting the at least one water jet, and that the control is configured to carry out the method according to one of claims 1 to 7.

[0046] Surprisingly, it has been shown that directing the airflow over the sensor or its section significantly reduces contamination of the sensor or its section in a simple manner. This creates a kind of air curtain that greatly reduces the impact and settlement of dust, water droplets, or slurry / bentonite suspension on the sensor, thus also significantly reducing the cleaning frequency and consequently the interruption of the installation of the tunnel lining segments.

[0047] Furthermore, it has been surprisingly shown that combining compressed air jets and water jets can enhance the cleaning effect while simultaneously significantly reducing the required amount of water. Another aspect of the invention provides that the at least one opening for delivering the at least one air stream is a nozzle, preferably a flat nozzle or at least two, preferably more than four, parallel point nozzles, and / or that the at least one opening for delivering the at least one water jet is a nozzle, preferably a fan nozzle or cone nozzle. This improves the delivery effect for cleaning and maintenance.

[0048] A further aspect of the invention provides that the at least one opening for releasing the at least one airflow is switchable, preferably with at least one solenoid valve, and / or that the at least one opening for releasing the at least one water jet is switchable, preferably with at least one solenoid valve. This makes the method according to the invention particularly easy to implement and control.

[0049] A further teaching of the invention provides that the sensor is arranged in a housing and that the at least one opening for releasing the at least one airflow and / or the at least one opening for releasing the at least one water jet is / are arranged on the housing.

[0050] A further teaching of the invention provides for the use of the sensor arrangement according to one of claims 8 to 11 in an installation device for the automated installation of at least one tunnel lining segment of a tunnel lining ring for the construction of a tunnel section driven by a tunnel boring machine, which can be coupled to the tunnel boring machine, wherein the installation device has, but is not limited to, the following features:

[0051] • a manipulator with at least one tool for picking up, holding and placing the at least one tunnel lining segment, and with at least one actuator for moving the at least one tool, wherein the at least one tool is movable by means of the at least one actuator in a radial, tangential and / or axial direction with respect to the machine axis of the tunnel boring machine in the space of the tunnel section constructed by the tunnel boring machine,

[0052] • at least one tool position sensor, provided on the manipulator and / or tool, for recording the respective actual position and orientation of the tool in the space of the tunnel section,

[0053] • at least one tunnel lining segment sensor, provided on the manipulator and / or tool, with which the actual position and / or actual location of at least one section of at least one already arranged tunnel lining segment can be detected, and / or with which the actual position and / or actual location of the respective tunnel lining segment to be placed can be detected,

[0054] • at least one controller that accesses installation data of the tunnel lining segments and that accesses the measurement data of the at least one tool position sensor and the at least one tunnel lining segment sensor, and with which, based on the installation data and measurement data, the at least one actuator and the at least one tool can be controlled in order to move the tool from the pickup position to the target placement position of the respective tunnel lining segment, to align it in the actual placement position and to position the tunnel lining segment against at least one already placed tunnel lining segment of a tunnel lining ring,

[0055] It is advantageous that at least two tunnel expansion segment sensors are provided as part of a sensor arrangement according to the invention, wherein the tunnel expansion segment sensor is preferably a time-of-flight camera.

[0056] The invention is explained in more detail below with reference to a preferred embodiment in conjunction with a drawing. The drawing shows...

[0057] Figure 1 shows a spatial view of an erector of an installation device with a tunnel lining segment installed.

[0058] Figure 2 shows a spatial representation of a sensor arrangement according to the invention.

[0059] Figure 3 shows the sensor arrangement according to the invention as shown in Figure 2 in clean mode,

[0060] Figure 4 shows the sensor arrangement according to the invention as shown in Figure 2 in the first

[0061] Cleaning mode,

[0062] Figure 5 shows the sensor arrangement according to the invention as shown in Figure 2 in the second

[0063] Cleaning mode, and

[0064] Figure 6 shows a block diagram of the method according to the invention.

[0065] Figure 1 shows an erector 10 of an installation device with a base support 11 on which connecting elements 12 for connection to a tunnel boring machine (not shown) are arranged. The connecting element 12 is shown here as a flange. A manipulator 20 is arranged on the base support 11, on which, for example, at least one carriage 13 is provided, which here, for example, has sliding guides 14 on both sides. Guide elements 15, for example, are also arranged as part of the manipulator 20 and are movable in the sliding guides 14. The guide elements 15, on which, for example, the rotary frame 16 is also arranged as part of the manipulator 20, are displaceable in the direction of arrow A via cylinders 19 as actuators.

[0066] For example, a rotary frame 16, as part of the manipulator 20, is arranged on the guide elements 15. The rotary frame 16 has a rotary drive 17 as an actuator. For example, a rotary ring 18, as part of the manipulator 20, is rotatably arranged on the rotary frame 16. The rotary ring 18 can perform a rotational movement on the rotary frame 16 via the rotary drive 17 as an actuator. The rotary ring 18 is movable in the direction of arrow B.

[0067] A manipulator arm 21, as part of the manipulator 20, is arranged on the rotating ring 18. It can be rotated with the rotating ring 18. The manipulator arm 21 is pivotable relative to the rotating frame 16, for example. This is achieved, for example, by at least one cylinder 22 acting as an actuator. An erector head 23 is provided as a tool on the manipulator arm itself. This serves to receive a tunnel lining segment 110. The erector head 23 is moved radially in the direction of arrow C, for example, by actuating the cylinders 22.

[0068] For fine-tuning the position of the tunnel lining segments 110, the erector head 23, for example, has a rotation capability in the direction of arrow D via the cylinder 24 as an actuator. Furthermore, the erector head 23 has, for example, movement elements 25 as actuators, by which the tunnel lining segment 110 can be tilted in the direction of arrow E or pivoted in the direction of arrow F.

[0069] The tunnel lining segment 110 is picked up at a receiving position analogous to the arrangement of the erector head 23 shown in Figure 1. The tunnel lining segment 110 is transported to the receiving position, for example, by a segment feeder (not shown). By controlling the cylinders 19, 22, 24, the motion elements 25, and the rotary drive 17 via a controller (not shown), the tunnel lining segment 110 can be positioned in the tunnel section driven by the tunnel boring machine by moving it in the directions of arrows A to F. The controller moves the tunnel lining segment 110 to its target position. The erector head 23, on which the tunnel lining segment 110 is located, is moved into the corresponding position by the controller via the actuators 17, 19, 22, 24, and 25.

[0070] In order to determine the current position of the tunnel expansion segment 110 in conjunction with the already placed tunnel expansion segments 110, the tunnel expansion segment 110 to be laid is scanned using sensor arrangements 200, which have sensors 210, preferably tunnel expansion segment sensors, for example a time-of-flight camera, other sensors such as lidar, radar, laser as point sensors or as profilometers, and stereo vision cameras, for example in the form of 2 CCD 2D cameras from which a 3D image is created, as well as CCD cameras as 2D sensors are possible, and if necessary, for example with a CCD camera as a 2D sensor as an additional tunnel expansion sensor (not shown).

[0071] The use of the tunnel lining segment sensors / sensor arrays 200 allows for the detection of longitudinal joint spacing and annular joint spacing, as well as any inclination error of the tunnel lining segment 110 to be installed in relation to the already installed tunnel lining segments. Based on this data, the control system can then activate the actuators accordingly, for example, to insert dowels into the designated openings 130 and simultaneously position the tunnel lining segment 110 to be installed at its actual position. If necessary, the data from the tunnel lining segment sensors are combined, summarized, or superimposed to enable improved detection.

[0072] The target position is controlled, for example, by using measuring sensors to detect the individual movements of the actuators. This allows the control system to precisely determine the current position of the tool or the erector head 23 in space. Based on the known dimensions and other guidance aids (not shown here) used for picking up the tool with the erector head 23, the position of the tunnel lining segment 110 to be placed is also indirectly known. The control system can then move the tunnel lining segment 110 to the target placement location. If necessary, active obstacle detection also takes place, for example, via the additional tunnel lining segment sensor.Only from this point onwards is it useful to monitor the actual positions by means of recording by the tunnel expansion segment sensors / sensor arrangements 200 which have sensors 210, for example a 3D recording by time-of-flight cameras, by monitoring the scan areas and directly determining the actual longitudinal joint distances and ring joint distances as well as any inclination errors.

[0073] The tunnel lining segment 110 is then pressed into its final position within the tunnel lining ring using thrust jacks (not shown). The tool / erector head 23 preferably remains on the positioned tunnel lining segment and is moved into its final position by the thrust jacks. This movement is preferably recorded so that the final position can be documented.

[0074] For example, a pin (not shown) is used to pick up the tunnel support segment 110, which is connected, for example, in the middle of the tunnel support segment 110. The erector head 23 is moved in the direction of arrow A to pick up the pin and thus establish a connection between the erector head 23 and the tunnel support segment 110, so that the tunnel support segment 110 can be moved from the pick-up position to the desired placement position.

[0075] To detect the pin, a further sensor arrangement 200, preferably a tunnel lining segment sensor, is provided, which is arranged on the erector head 23. This sensor has a detection area located in front of the erector head 23 to ensure optimal timely detection of the pin. Once this has occurred, the position of the tool is aligned by the control system using actuators 17, 19, 22, 24, 25 so that the erector head 23 can preferably move into the pin in the direction of arrow A. The further tunnel lining segment sensor is preferably a time-of-flight camera. This camera can preferably provide both 3D and 2D images.

[0076] Figure 2 shows a sensor arrangement 200 according to the invention with a sensor 210 in a housing 250. The sensor 210 has a section 220 for outputting and / or receiving a measurement signal (not shown).

[0077] The sensor arrangement 200 has a water opening 230, here for example in the form of a nozzle, preferably in the form of a hollow cone nozzle, and two compressed air openings 240, here for example in the form of a nozzle each, preferably in the form of a flat nozzle, which preferably has several parallel outlets 241.

[0078] Figure 3 shows the use of the sensor arrangement 200 in the clean-up mode of the inventive method or in the drying mode of the inventive method. For clean-up mode, the flat nozzles 240 preferably used here emit an "air curtain 260", shown here as several parallel air jets 261. The air jets 261 of the air curtain 260 flow over the sensor 210 and, in particular, over the section 220. It has surprisingly been found that this largely prevents dust, water droplets, or even slurry / bentonite suspension from settling on the sensor 210 or its section 220. Advantageously, clean-up mode is carried out at least during the measurement operation of the sensor arrangement 200, as long as the limit value of the degree of contamination is not exceeded.Preferably, the clean operation is also carried out during the periods between two measurements of the measuring operation, as long as the limit value of the degree of pollution is not exceeded.

[0079] During drying, air jets 261, possibly with varying volume flow and pressure, are also directed over sensor 210 and, in particular, over section 220 for maintenance purposes. This causes the removal and / or drying of the water present on sensor 210 / section 220, which may be in the form of droplets, for example.

[0080] Figure 4 shows the use of the sensor arrangement 200 in the reduced cleaning mode of the process. Here, however, only a water jet 270 is shown initially, which is preferably discharged in the form of a fan 270 from the outlet 231 of the opening 230. The air curtain 260 or the air jets 261 are not shown here, or are omitted for a purely water-based cleaning step, which, for example, may preferably only be used in cases of light soiling.

[0081] Figure 5 shows the use of the sensor arrangement 200 in full cleaning operation of the process. Here, both the water jet 270, preferably in the form of a fan 270 emitted from the outlet 231 of the opening 230, and the air curtain 260, preferably depicted here as air jets 261, are shown. The air jets 261 and the water jet 270 overlap above the sensor 210 and the section 220, respectively.

[0082] Surprisingly, it has been shown that by overlapping the discharged compressed air and the discharged water jet, it is possible to clean the sensor 210 or its section 220 particularly efficiently, while keeping the discharged amount of water as low as possible in order not to excessively contaminate the working area.

[0083] Figure 6 shows the inventive method as a block diagram. At point 300, the necessary components of the sensor arrangement are provided as described above.

[0084] The process begins at point 400. This refers to the procedure in which sensor 210 is used for measurement (sensor measurement operation) in sensor arrangement 200, as, for example, in the procedure for the automated installation of a tunnel expansion segment. This also includes the pause between two operating phases of sensor 210, during which maintenance, cleaning, and contamination detection are carried out. Preferably, however, the procedure is started / executed shortly before the sensor measurement operation begins.

[0085] The entire process is carried out, monitored, and controlled, for example, by a controller at point 900. The controller at point 900 stops the process at point 1000 or starts it at point 400, depending on which parameters are implemented or not.

[0086] The process here initially includes point 500, at which the degree of contamination is determined on sensor 210 or section 220.

[0087] The pollution level is then evaluated at point 600. If the pollution level is less than a limit value, the process branches off to point 610. If the pollution level is greater than a limit value, the process branches off to point 620.

[0088] If the degree of contamination on section 210 is less than the limit value, cleaning is carried out at point 700. For this purpose, compressed air is released at point 710 at an initial pressure and volume flow rate, for example, using the flat nozzles 240, by creating an air curtain 260 above sensor 210 / section 220 through the release of parallel air jets 261. The process then continues at point 500, where the degree of contamination is determined again. The process is then repeated accordingly.

[0089] If the evaluation at point 600 reveals that the degree of pollution at point 620 is greater than the limit value, the procedure continues at point 800 by activating the cleaning process.

[0090] For this purpose, the control system can stop the process (for example, picking up and placing a tunnel segment) at point 1000. However, if the cleaning can be carried out quickly enough, this can be omitted and the process step can continue accordingly. Interrupting the process is preferred, though.

[0091] The cleaning process can therefore be continued, for example, at step 810 by first stopping the delivery of compressed air through the nozzles 240 at the first pressure and volume flow rate. Subsequently, according to step 820, the delivery of compressed air can be continued at a second volume flow rate and a second pressure. In addition, the opening 230, for example the hollow cone nozzle, is activated and a water jet 270, preferably in the form of a fan, is delivered over or onto the section 220 of the sensor 210.

[0092] The mixing of the water jet 270 and the air jet 260 / 261 results in a particularly good cleaning effect on section 220 / sensor 210.

[0093] The release of air and water onto section 220 is preferably time-controlled, for example over a duration t1. Alternatively, the degree of soiling on the surface can be measured during cleaning. The duration t1 can be defined depending on the soiling medium.

[0094] After completion of cleaning step 820, at point 830 the water supply is stopped and instead, to dry section 220 / sensor 210, only air is supplied, either continuing at the second pressure and second volume flow rate or at a fourth pressure and a fourth volume flow rate, for a sufficient further time t2 to remove the water on section 220, for example by blowing it away or by drying.

[0095] After the time period t2 has elapsed at point 830, the procedure is continued again at point 500.

[0096] If the level of contamination is sufficiently low again and the measurement of sensor 210 is therefore sufficiently accurate again, the process is restarted at point 400 by the control system and the cleaning process is started again at point 700.

[0097] If the cleaning effect is still insufficient and the degree of contamination is therefore still higher than the limit value, the cleaning process 800 is repeated accordingly. Keeping the sensors clean ensures sufficiently accurate measurement, allowing the respective process in which the sensors 210 are used to be carried out with sufficient accuracy.

Claims

Patent claims Method for keeping clean and cleaning a sensor arrangement with at least one non-contact operating sensor for carrying out a measurement comprising the steps:

1. Providing a sensor arrangement with at least one non-contact sensor having a section for emitting and / or receiving a measurement signal, 2. Providing at least one opening connected to a supply line for delivering at least one airflow over and / or onto the section and at least one opening for delivering at least one water jet onto the section of the sensor arrangement, 3. Providing at least one opening connected to a supply line for delivering at least one jet of water onto the section of the sensor arrangement, 4. Providing control valves for adjusting pressures and flow rates at the openings, 5. Providing a computer-based control system for adjusting pressures and flow rates at the openings, 6. Determining the degree of contamination of the sensor section, 7. Determine whether the pollution level is below or above a pollution limit.

8. Release an airflow over the sensor section at least during the measurement process with a first preset pressure and a first preset volume flow rate, as long as the degree of pollution is below the pollution limit, 9. Release an airflow over the sensor section with a second preset pressure and a second preset volume flow and release. a water jet together with the release of the airflow with a third preset pressure and a third preset volume flow, both for a first time interval, as soon as the degree of pollution exceeds the pollution limit, 10. Stop the water jet but continue to release the airflow over the sensor section at the second or a fourth preset pressure and at the second preset or a fourth volume flow for a second time interval, 11. Determining the degree of contamination of the sensor section, 12. Repeat the procedure from step 7.

2. Method according to claim 1, characterized in that a nozzle, preferably at least two parallel arranged point jet nozzles or at least one flat jet nozzle, is provided as an opening for releasing at least one air stream.

3. Method according to claim 1 or 2, characterized in that a nozzle, preferably a fan nozzle or cone nozzle, is provided as an opening for releasing at least one jet of water.

4. Method according to one of claims 1 to 3, characterized in that the first volume flow of the airflow is reduced to 12 to 16 m³ in the event of contamination with a sludge or bentonite suspension during the measurement operation. 3 / h distributed across the number of nozzles at 0.5 to 2 bar, preferably 13 to 15 m 3 / h at 0.75 to 1.5 bar, particularly preferably 14 m 3 / h at 1 bar, is set.

5. Method according to one of claims 1 to 4, characterized in that the release of an airflow over the section of the sensor during the measurement is continuous or pulsed.

6. Method according to one of claims 1 to 5, characterized in that the second volume flow of the airflow is reduced to 20 to 40 m³ in the event of contamination with a sludge or bentonite suspension. 3 The output is distributed across the number of nozzles at a pressure of 5 to 6 bar.

7. Method according to one of claims 1 to 6, characterized in that the third volume flow of the water jet, in the event of contamination with a sludge or bentonite suspension, is distributed over the number of nozzles at 0.5 to 10 bar to 0.5 to 3 l / min. preferably 1.1 to 2 l / min at 1 to 7 bar, particularly preferably 1.6 to 1.8 l / min at 6 bar.

8. Sensor arrangement with at least one non-contact sensor, which has a section for emitting and / or receiving a measurement signal, with at least one opening for emitting at least one airflow over and / or onto the section and at least one opening for emitting at least one water jet onto the section, characterized in that a control is provided which switches the at least one opening for emitting the at least one airflow and / or the at least one opening for emitting the at least one water jet, and that the control is configured to carry out the method according to one of claims 1 to 7.

9. Sensor arrangement according to claim 8, characterized in that the at least one opening for emitting the at least one airflow is a nozzle, preferably a flat nozzle or at least two, preferably more than four parallel point nozzles, and / or that the at least one opening for emitting the at least one water jet is a nozzle, preferably a fan nozzle or cone nozzle. 10 Sensor arrangement according to claim 8 or 9, characterized in that the at least one opening for the emission of the at least one airflow is switchable, preferably with at least one solenoid valve, and / or that the at least one opening for the emission of the at least one water jet is switchable, preferably with at least one solenoid valve.

11. Sensor arrangement according to one of claims 8 to 10, characterized in that the sensor is arranged in a housing and that the at least one opening for releasing the at least one airflow and / or the at least one opening for releasing the at least one water jet is / are arranged on the housing.

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