EP4245922A1 - Ground milling machine with a cleaning system for a camera and method - Google Patents

Abstract

Ground milling machine (1) for processing a soil (8), in particular a road milling machine, recycler or stabilizer, comprising a machine frame (3) carried by driving devices (6, 38) with a driver's cab (2) for an operator, a milling device, at least one camera ( 12) for recording image information of an external environment and / or an external view of at least a part of the ground milling machine (1), the camera (12) having a recording area (13) with a transparent element (37) through which it records the image information , a control device (20) which receives the image information from the camera (12), a fluid tank (14) with a cleaning fluid and/or a compressed air tank (15) which is connected to a line system (19), wherein a cleaning outlet (22 ) is present, which is connected to the line system (19) via a valve (18) controlled by the control device (20) and is designed to clean the transparent element (37) with fluid from the fluid tank (14) and / or compressed air from the compressed air tank (15), the control device (20) being designed to initiate cleaning of the transparent element (37) depending on a work situation or depending on the image information.

Description

The invention relates to a ground milling machine for milling the subsoil, such as a road milling machine, a recycler or a stabilizer. In addition, the invention relates to a method for cleaning a transparent element arranged in a recording area of a camera of a ground milling machine, which is in particular the above-mentioned ground milling machine.

Generic ground milling machines are typically used in road and path construction as well as in the construction of squares. These are usually self-propelled machines that have a machine frame supported by driving devices with a driver's cab for an operator. They comprise a milling device with a milling drum rotatably mounted in a milling drum box about an axis of rotation for removing soil material. The milling drum is usually equipped with a variety of tools, for example milling cutters, which are driven into the soil to be milled by the rotation of the milling drum and remove it. The removed material is loaded onto a transport vehicle, such as a truck, via a conveyor device. With recyclers and stabilizers, the removed material can also be left on site, for example to create a new road surface or stabilized soil.

Such ground milling machines typically also have a fluid tank with a cleaning fluid and/or a compressed air tank. The tank or tanks are connected to a line system, via which in particular the fluid and/or the compressed air are transported to removal or discharge points of the ground milling machine. The cleaning fluid of the fluid tank can be, for example, water. For example, it is known to spray the milling device of the ground milling machine with water during operation, for example to cool a milling drum, to increase the service life of the cutting devices and/or to bind dust. Loose soil material can also be sprayed with water during removal to prevent dust from forming to reduce. The compressed air tank is typically filled with compressed air by a compressor arranged on the ground milling machine. The compressed air can be used, for example, to operate tools for maintenance work on the ground milling machine, for example to change milling bits on the milling drum.

The generic ground milling machines are typically used on a wide variety of construction sites. The operation usually takes place from a control station, for example comprising a base, a seat and/or operating elements, etc. This control station can be designed to be open or closed, for example as a cabin. Depending on the specific circumstances, an operator's view from the driver's cab to various positions in the immediate vicinity of the ground milling machine may be difficult. In addition, the operator's direct view of various areas around the ground milling machine is already blocked by the machine itself or its outer contour. Even areas whose visibility would be helpful for precise control of the work process or control of the work result can often not be seen directly by the operator on the driver's platform. It is therefore known to provide at least one camera for recording image information of an external environment and/or an external view of at least part of the ground milling machine. In addition, there is typically a control device that receives the image information from the camera and, if necessary, evaluates and/or further processes it. For example, it can include a display device arranged in the driver's cab, which is designed to display the image information, and to which the control device optionally forwards the image information. The display device can be, for example, a display or a screen. The control device can be, for example, the on-board computer or part of the on-board computer of the ground milling machine. Such systems are, for example, from DE 10 2013 006 464 B4 known to the applicant.

During operation of generic ground milling machines, their external environment is often contaminated, for example by dust and/or vapors that can arise during operation. In order to protect the camera from these adverse circumstances, the camera typically has a recording area with a transparent element, with the camera recording the image information through the transparent element. The recording area refers to an area that is located directly in front of the camera in the viewing direction. In particular, components belonging to the camera can still be in the recording area, for example the lens of the camera that is furthest out or a pane that closes the lens of the camera to the outside. In addition, in the recording area, for example, there can be a protective pane behind which the camera is arranged, for example a window in a housing surrounding the camera. In the context of the present description, the transparent element is to be regarded as the element which protects the camera or the interior of the lens and/or the camera from a potentially contaminated external environment, for example through the construction site contaminated external environment, separates. The camera therefore looks through the transparent element into the outside surroundings of the machine. The transparent element can therefore be, for example, the outermost lens of the lens or camera, a protective glass arranged on the lens or camera, or another protective device or pane that is arranged in the area in front of the camera, for example in the frame of a housing surrounding the camera. The transparent element considered here therefore protects the camera or the lens of the camera, in particular an image recording sensor of a digital camera, from contamination. The transparent element is therefore a protection for the camera, with which the camera or its optics are protected from negative influences from the construction site environment.

During operation of the ground milling machine, dust and/or vapors often occur in the area surrounding the ground milling machine. These also come into contact with the transparent element, so that dust and/or vapors can settle on the transparent element and contaminate it. Such deposits or contamination of the transparent element make the camera's view through the transparent element of the area to be recorded worse. The image or image information recorded by the camera deteriorates. This can go so far that the image information captured by the camera is practically useless and no longer of any help. In order to improve the image information again, the transparent element must then be cleaned, which frees the camera's view through the transparent element again.

It is the object of the present invention to provide an advantageous option for cleaning the transparent element. In particular, this should not require any interruption to the operation of the ground milling machine. In addition, the transparent element should be cleaned regularly and at an early stage so that the image information recorded by the camera is of high quality throughout the entire work operation and one does not wait until the transparent element has become heavily soiled. At the same time, however, for economic and ecological reasons, no unnecessary cleaning of the camera or the transparent element should be carried out if possible, or this should only be done when it probably or actually makes sense.

The problem is solved using a ground milling machine or a method according to the independent claims. Preferred further developments are specified in the dependent claims.

Specifically, the solution is achieved in the case of a generic ground milling machine mentioned at the beginning in that a cleaning outlet is present, which is connected via a valve controlled by the control device and / or a fluid delivery device controlled by the control device Line system connected and designed to apply fluid from the fluid tank and / or compressed air from the compressed air tank to the transparent element for cleaning. The control device is designed to initiate cleaning of the transparent element depending on a work situation and/or depending on the image information. The image information is, for example, an image recorded by the camera or the data that defines an image, for example in digital form. This is therefore, in particular, image information from an image currently recorded by the camera. The fact that the control device causes the transparent element to be cleaned means in the present case that the control device controls one or more valves and/or the fluid delivery device, in particular a pump device, for example a pump, in such a way that cleaning fluid reaches the cleaning outlet and the transparent element via the cleaning outlet Fluid, for example water and / or compressed air, is applied. Additionally or alternatively, however, initiating cleaning by the control device can also mean that the control device displays information to the operator that cleaning is necessary, whereupon the operator starts the cleaning by entering a control command. The corresponding information about the need for cleaning is output, for example, via the display device, which will be explained in more detail below. Alternatively, a warning light or an acoustic signal can also be provided to indicate to the operator that cleaning is necessary. The transparent element is cleaned by spraying or spraying it with the fluid, in particular a liquid fluid such as water and/or a gaseous fluid such as compressed air. The cleaning outlet is preferably a device via which the cleaning fluid from the line system can be specifically applied to the transparent element. For example, the cleaning outlet is a cleaning nozzle. By spraying with cleaning fluid, the transparent element is freed from dirt, so that the image information or the camera's view through the transparent element is improved. In principle, the control device can carry out cleaning of the transparent element when an operator enters a corresponding control command, for example after the control device has indicated to the operator that cleaning is necessary. However, it is advantageous if the control device carries out cleaning automatically. For this purpose, the control device uses a working situation of the ground milling machine and/or the image information supplied by the camera itself, analyzes it, and decides based on the result whether cleaning is to be carried out or not, as will be explained in more detail below. The transparent element in particular comprises a glass, preferably anti-reflective glass, for example a glass with the trade name Conturan (brand name of Schott AG).

So that the control device can initiate cleaning depending on a work situation, it is advantageous if the control device is designed in such a way that it recognizes different operating states of the ground milling machine and, for example, their presence Records absences and/or their duration and uses them as a basis for a decision as to whether cleaning will be carried out or not. The work situation used by the control device includes, for example, switching on or switching off the ground milling machine. For example, the control device can initiate cleaning at the start and/or end of machine operation, in particular at each start and/or end of machine operation. The start and/or end of machine operation can be defined, for example, by the operation of an internal combustion engine or electric motor (for example electric traction motors) and/or by the operation of the control device. In addition, the work situation may include a start or an end to a work operation and/or a transport operation. The working operation describes, for example, an operation of the ground milling machine in which the milling device is used for soil cultivation, specifically for milling the ground subsoil. It can therefore in particular be a milling operation and thus be characterized in particular by the operation, particularly rotational operation, of the milling drum. The transport operation, on the other hand, describes, for example, an operation of the ground milling machine in which the milling device of the ground milling machine is not used for soil cultivation, in particular in which the milling drum is stationary relative to the machine frame of the ground milling machine. In transport operations, the ground milling machine is moved, for example, within the construction site or between construction sites, for example by operating its own driving devices. Here too, it is preferred that the control device initiates cleaning at each start and/or end of a work operation and/or a transport operation. In ground milling machines, the milling drum is typically height-adjustable so that different milling depths can be achieved. The work situation can now also include lowering or raising the milling drum. In this case, the control device can always initiate cleaning when the height setting of the milling drum or the milling depth of the ground milling machine is changed.

In addition, a time-controlled cleaning, in particular using a timer or a timer function, which monitors time intervals can be provided as a supplement or alternative. The work situation can then include, for example, the expiration of a time interval, for example related to an operation or a working operation of the ground milling machine. The operation of the ground milling machine is, for example, the time interval between switching the ground milling machine on and switching it off. The work operation is defined as already explained previously. In addition to or as an alternative to a time interval, a distance can also be used, so that the work situation includes the achievement of a distance, for example in relation to the already explained operation or working operation of the ground milling machine. Both the timer or the monitoring of a time interval as well as the monitoring of a distance can be provided for each operation described herein as a work situation. The timer function can be carried out by the control device, which is designed accordingly and, for example, has a suitable computer program.

The work situation can also additionally or alternatively include the achievement of a threshold value. This can be, for example, a threshold value of the weight or volume of soil material overloaded by the ground milling machine onto a transport vehicle. For example, the ground milling machine can have a loading assistant or a loading assistance system that monitors the loading of the transport vehicles. This can be used, for example, to determine the overloaded weight or the volume of the floor material. If a threshold value for the weight or volume of the floor material is exceeded, the control device can initiate cleaning. Additionally or alternatively, the threshold value can also be the threshold value of a counter, for example a counter for the number of machine starts or the transport vehicles loaded by the ground milling machine. In this case, a counting device is present, which records, for example, the number of machine starts and/or the number of transport vehicles loaded by the ground milling machine. If the counter exceeds the threshold value, the control device initiates cleaning. In principle, such a counter can be used for any work situation described here that does not describe permanent operation of the ground milling machine but only time-limited processes, for example the start of work, the end of work, lowering or raising the milling drum, etc. The specific threshold values, i.e. their numerical values, can be predetermined be. In a preferred embodiment it is provided that the threshold values are adjusted dynamically. For this purpose, the control device records, for example, how often an operator manually starts cleaning the transparent element using a corresponding control command without the control device having previously indicated to him that cleaning is necessary. Depending on the frequency of these manual cleanings, the threshold value can be adjusted by the control device. This happens, for example, in such a way that the threshold values are lowered if the operator initiates manual cleaning regularly, for example 1, 2, 3 or 4 times per hour. On the other hand, if the operator never or rarely initiates manual cleaning, the threshold values can be raised to avoid unnecessary cleaning.

Finally, in addition or alternatively, it can also be provided that the work situation includes a start or an end of an operation and/or a type of operation of a water spray system for moistening the milling device and/or the removed soil material. Generic ground milling machines can include water spray systems, for example to spray roller bandages or milling drums or removed soil material with water. Spraying the milling drum cools it and extends the service life of the chisels used. The switching on and/or switching off of such a water spray system can now be used as a working situation that is taken into account by the control device to initiate cleaning of the transparent element. In particular, the control device is preferably also designed to control the operation of the water spray system. Also the duration of operation the water spray system can be taken into account. In the present case, the type of operation of the water spray system is understood to mean, for example, the volume flow of the water spray system and/or what proportion of available water nozzles are currently being used and/or which systems of the ground milling machine are currently being sprayed with water. All of these factors can be taken into account by the control device and result in the transparent element being cleaned at systematic intervals. This reliably avoids excessive contamination of the transparent element and the associated deterioration of the camera's image information. On the other hand, unnecessary cleaning of the transparent element is avoided, which is associated with higher material consumption and the associated higher costs. It can also be provided that the water spray system and the cleaning outlet are supplied with the same fluid, for example water, from the same tank, for example the fluid tank. The fluid is therefore used, for example, both for cleaning the camera and for cooling the milling drum, with only one common tank for the fluid being provided for both applications.

Additionally or alternatively, the control device can also initiate cleaning of the transparent element depending on the image information. For this purpose, it can preferably be provided that the control device is designed in such a way that it evaluates the image information as part of dirt detection and initiates cleaning of the transparent element if the dirt detection detects that the transparent element is dirty. If the transparent element becomes dirty, the image information recorded by the camera changes. Accordingly, contamination of the transparent element can be derived based on the image information or based on the change in the image information. In this case, contamination can be concluded solely from the image information provided by the camera. For this purpose, the control device can, for example, record parameters of the image information, as will be explained in more detail below, and store them in a memory over a certain period of time. In this way, a change in the parameters over time can be determined, which can be used as a sign that the transparent element is dirty.

For example, various characteristic values of the image information that are common in image processing can be used as parameters. For example, it is preferred that the control device is designed to use parameters for dirt detection, such as brightness and/or contrast and/or saturation and/or image sharpness and/or relative luminescence and/or pattern recognition in part of the Image information or in the entire image information. The parameters mentioned can be read or determined directly from the image information or a part of it. In part of the image information means that, for example, different areas of the image can be viewed. For example, the image can be divided into quadrants, i.e. in particular four rectangular subareas of the same size, be divided or concentric areas are used, for example an edge area and one or more central areas surrounded by the edge area. Of course, the entire image can also be used. The relative luminescence can take into account the RGB composition, i.e. the proportion of red, green and blue light, of individual pixels of the image information. Pattern recognition is based on the knowledge that contamination of the transparent element can have characteristic consequences for the image information. For example, different areas of the image can have different brightness when dirty, although they are equally bright when the transparent element is clean. An example of such pattern recognition would therefore be if the control device determines that the edge area of the image information, i.e. the outer edge of an image, is significantly darker than the center of the image. Additionally or alternatively, it can be determined, in particular via an image comparison explained in more detail below, whether areas darken continuously over time, which ultimately indicates an increasing level of pollution. It is also possible to check the available image information, in particular again using the image comparison described in more detail below, for patterns that do not change over time or over the ongoing work process. In this way, image information that goes back to recorded objects that go beyond the transparent element and thus changes over time in the work process, such as the external environment and / or the ground, can be separated from image information that goes back to dust particles adhering to the transparent element and that change so that they do not change or change differently over time in the work process. This enables a statement to be made as to whether a dust particle adheres to the transparent element and/or whether a level of contamination that requires cleaning has been reached on the transparent element. Such patterns can be used to detect dirt. It can be provided that one or more limit or threshold values are defined for one and/or several of the parameters for dirt detection, if these are exceeded or fallen below, it is then assumed that a contamination condition requires cleaning. If it is determined based on the parameters mentioned that there is contamination of the transparent element or that cleaning of the transparent element is sensible and/or necessary, the control device initiates cleaning.

A particular focus when evaluating the image information by the control device is preferably on changes to the image information. It is therefore preferably provided that the control device is designed to detect changes in the image information over time and to detect contamination of the transparent element when the changes exceed a threshold value. For example, contamination can be detected if the above-mentioned parameters of brightness and/or contrast and/or saturation and/or image sharpness and/or pattern in the current image information deviate from previous values, in particular when the transparent element is clean. In image processing, it is common practice to record such parameters numerically, so that they can also be compared A threshold value for the still permitted change can simply be set, if this is exceeded the control device concludes that there is contamination and initiates cleaning. For example, the control device can use the image information to determine that the brightness of the image, for example partially and in particular overall, has decreased by a certain percentage. The control device can of course compensate for the influence of external lighting conditions. The percentage that serves as a threshold value here can be in the range >0% to 100%, for example preferably 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50 %. If the detected change in the parameter under consideration, for example the brightness, exceeds this threshold value, the control device concludes that there is contamination and initiates cleaning. Additionally or alternatively, it can also be provided that the control device evaluates whether the image information in parts of the image or the image information changes over time, with contamination of the transparent element being detected if the changes fall below a threshold value. For example, if the transparent element were so dirty that no light could penetrate through the transparent element, the image recorded by the camera or the image information recorded would no longer change over time at all, but would always remain the same. This effect becomes noticeable when the transparent element is less dirty because the parameters of the image information mentioned change less over time than when the transparent element is clean. It can therefore be provided that the control device evaluates the temporal changes in the image information and detects contamination if the temporal changes in the image information fall below a threshold value. The threshold value can also be specified here, for example, in percent. If the parameters of the image information no longer change over time in the same way as when the transparent element is clean, there is contamination. The threshold value can be, for example, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55% or 50% of the changes over time of the respective parameter with a clean, transparent element. If there are less severe changes over time, the control device initiates cleaning of the transparent element due to the contamination. In order to be able to determine temporal changes in the image information or at least part of it, a current image can, for example, be compared with one or more images that are older with respect to a time interval, for example at a time interval of one or more minutes. This process can take place regularly throughout the work process in particular. For a specific comparison, for example, one or more of the parameters mentioned in the previous paragraph can be used. It is preferred if the reference image is recorded at the start of the machine, at the start of work and/or after a cleaning process. It can be additionally or alternatively provided that a new reference image is recorded after each successive cleaning process.

Due to the known working process of the ground milling machine, it may be possible to essentially predict in advance, especially with regard to some parameters, which image information is to be expected or in which range parameters can and should lie, especially if the transparent element is sufficiently dirt-free. Accordingly, the control device can be programmed in software based on the expected image information, so that contamination is detected if the image information recorded by the camera deviates from expected image information, for example beyond the threshold values already mentioned above. However, it is particularly helpful if a reference is also arranged in the field of view of the camera, the appearance of which is also known, so that changes in the appearance of the reference indicate that the transparent element is dirty. In a preferred embodiment it is therefore provided that the control device is designed to detect a reference detected by the camera, for example a light source, a contour of the machine or a pattern arranged in particular in the recording area of the camera on the machine or on the transparent element itself. to be used for dirt detection. The reference is in particular arranged in a known position relative to the camera, so that it is known in which part of the image information the reference is located. The reference can be a permanent reference, for example a contour or a pattern in the camera's field of view, which is always present and which should therefore always look the same in the image information. This can be, for example, parts of the ground milling machine or outlines of parts of the ground milling machine. Alternatively, the reference can also be a temporary reference, for example a light source that is only switched on temporarily. Since the effect of switching on the light source on the image information when the transparent element is clean is known, a correspondingly different or weakened change in the image information can be interpreted as an indication of contamination of the transparent element. This can also be quantified according to the percentage values already given above. The light source can also be different light sources. For example, the light source may emit light of a specific color, such as white, green, red, blue or yellow light. The light source preferably emits light of a color that differs from other light sources on the ground milling machine and/or on the construction site, and in particular daylight. In this way, the change in the image information due to switching on the light source can also be clearly assigned to the light source.

In addition or alternatively, it is also possible to create a reference image or a reference structure temporarily or at certain times, for example depending on the situation (machine start, milling start, manually triggered, etc.) and/or after defined time intervals have elapsed, in particular using a suitable projection device, for example a Laser or a spot to project into the recording area of the camera, for example on the floor and / or on a part of the machine. This can be a defined structure, for example in a pattern like a grid, a shape or something similar, for example a company box, etc. This reference image or this reference structure is always the same with regard to certain parameters, for example size, shape, brightness, etc., so that deviations that occur due to contamination of the transparent element , can be identified particularly easily and precisely in quantitative and qualitative terms in the captured image. Here too, it can be provided that the projection is activated permanently, only in certain work situations, for example when milling, only at certain time intervals or only in certain situations, for example after a cleaning process. With the activation of the projection device, it can also be provided that a reference image is recorded at certain times, for example at the beginning of a work process, after a cleaning process, etc. It can also be provided that the activation of the projection device and / or the recording of a reference image is coupled in time, such that the projection device is only activated after cleaning and the reference image is then recorded.

It goes without saying that a suitable control unit can be provided to control the processes mentioned. This can be connected to appropriate sensors in order to obtain the information relevant to the triggering and/or sequence of the control processes mentioned. As already explained, in principle the entire image or only parts of the image or the image information can be used for evaluation by the control device. In addition to the above-mentioned qualitative changes in the image information or its parts, it can also be quantitatively evaluated in how many parts or to what proportions of the image information or the image there are changes. It is therefore preferably provided that the control device is designed to detect a change in parts of the image information, for example individual pixels, and to detect contamination of the transparent element when the proportion of the changed image information exceeds a threshold value. For example, as described above, the control device evaluates for different areas of the image or different parts of the image information, for example for each individual pixel of the image information, whether this has changes, for example changes over time. If the proportion of the observed areas with changed image information reaches or exceeds the threshold value, it is concluded that there is contamination. For example, contamination is concluded if the proportion of areas with changed image information, for example the proportion of pixels in the image, is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50% of the total areas considered, for example pixels. In this case, the control device can initiate cleaning of the transparent element.

Overall, the changes to the image information caused by contamination of the transparent element are diverse and are sometimes expressed by only slight changes in one or more parameters at the same time. It can therefore be difficult to find one or a few parameters can be identified that can be used to conclude whether contamination is present. It can therefore be advantageous to use software that is able to evaluate the large number of individual subthreshold changes overall or to use at least two or more parameters. The control device is preferably designed to evaluate the image information for dirt detection using software based on machine learning. The software was preferably trained in advance with a variety of image information, each of which is assigned to a clean transparent element or a dirty transparent element, in particular a transparent element that is dirty to different degrees. In this way, a large number of parameters can be included in the analysis at the same time, so that the software makes the decision as to whether the transparent element is dirty or not based on an "overall impression" of the image information, so to speak. Additionally or alternatively, it can also be provided that the software observes the behavior of the operator and, for example, determines under which conditions and/or in the presence of which changes the operator manually triggers a cleaning process during the ongoing work process.

In principle, it is sufficient for the present invention if the ground milling machine includes exactly one camera. However, it is preferred if it includes at least one and in particular a large number of cameras. In this case, all of the features described above apply to the at least one camera and preferably to all cameras. In particular, a corresponding cleaning outlet can be provided for each camera, via which the transparent element of this camera can be cleaned by the control device as described. The camera or cameras can basically be arranged anywhere on the ground milling machine and record any areas of interest for the operation of the ground milling machine. Areas that are difficult to see are particularly preferred, for example areas in a working direction of the ground milling machine immediately in front of, behind or transversely to the working direction of the ground milling machines next to the milling device. Particularly in the area of the milling device, the most dust and/or vapors typically arise during operation of the ground milling machine, so that the transparent element is particularly dirty in this area. Such a camera with cleaning device can be positioned in front of or behind the milling device, in particular on the underside of the ground milling machine, viewed in the milling direction. In a preferred embodiment, the ground milling machine additionally or alternatively comprises a transfer conveyor belt and a loading conveyor belt, wherein the transfer conveyor belt is designed to transport milled soil material from the milling roller box to the loading conveyor belt and the loading conveyor belt is designed to transport the milled soil material onto a transport vehicle. It has been shown that in particular an arrangement of the camera, for example with a viewing area at the material drop or viewing direction in the direction of the dropped milled material towards the transport vehicle, on the loading conveyor belt enables a particularly advantageous view of the operator for the loading process of the milled material. Other beneficial areas that come with The areas that can be viewed with a camera are the area in front of the ground milling machine, in particular below the loading conveyor belt, in the working direction of the ground milling machine in front of and behind the milling drum, in the transfer area between the transfer and loading conveyor belt, etc. A camera directed into one of these areas can become dirty comparatively quickly, so that equipping one or more of these cameras with a cleaning device as described above is particularly advantageous. It can also be provided that only one or a subgroup of the cameras present on the ground milling machine has such a cleaning device. In particular, cameras whose image information is used for automated and/or partially automated processes and/or which are positioned in locations that are difficult to access from outside the machine are equipped accordingly.

The ground milling machine preferably comprises a conveying device, for example a pump, connected to the line system for transporting fluid from the fluid tank. This can be, for example, a water pump if the fluid is water. The pump is designed in particular to build up a fluid pressure in the line system, which can be used, for example, to apply the fluid to the transparent element via the cleaning outlet. If the milling machine has a water spray system, the pump can be the same pump that supplies water to the water spray system. In other words, one and the same pump can be provided for the water spray system and for applying fluid from the fluid tank to the transparent element. In addition, the ground milling machine can include a compressor that fills the compressed air tank with compressed air. Such compressors are typically already present on generic ground milling machines. If there are several cameras on the ground milling machine, it is preferably provided that one cleaning outlet is provided for each camera, with a pump supplying this cleaning outlet with fluid being provided for each cleaning outlet, or with one pump being designed to supply all cleaning outlets with fluid . In addition, it can be provided that separate cleaning outlets are provided for fluid and compressed air.

In order to prevent the cleaning of the transparent element from being hindered at low temperatures, it can be provided that the cleaning outlet, preferably all cleaning outlets, and/or the fluid tank and/or the line system and/or the valve is/are designed to be heatable. For example, an electric heater or warm exhaust air from an internal combustion engine can be used for this purpose. Additionally or alternatively, a drain can be provided, via which the fluid tank and/or the line system can be emptied, in particular completely. This can be done purely by gravity or driven by the fluid delivery device or the pump. A suitable outlet for emptying the pipe system can be provided. This is helpful to prevent liquids from freezing in the respective components during long rest periods in cold temperatures. Appropriate emptying can also be done be initiated by the control device, in particular after inputting a control command from the operator.

As already stated, the cleaning fluid can be water. In a preferred embodiment, it can now be provided that the fluid for cleaning is provided with an additive, in particular a cleaning agent. The additive can already be mixed with the fluid in the fluid tank or the additive is arranged in a separate additive tank and is mixed with the fluid of the fluid tank outside the fluid tank, but preferably within the line system. The additive can be a solid or a liquid. These can be, for example, surface-active substances such as surfactants, alcohols or the like. In the case of a liquid, this can be provided in a separate additive tank and mixed with the fluid from the fluid tank in a constant ratio, for example via a gear, piston, diaphragm or water jet pump. By using a water jet pump to supply the additive, the one pump already described above is sufficient for the fluid. The other pumps can be controlled separately and the mixing ratio can be adjusted as desired. The cleaning effect can be increased by using an additive. In addition, it can be provided that the operator determines by input whether the additive should be used in the current operation or not. The control device is therefore designed to separate the additive tank from the line system or to connect it to it, for example via a valve. This allows the operator to select whether or not to use an additive present in the additive tank.

For cleaning, the transparent element can therefore be acted upon either with the fluid or with a mixture of the fluid and an additive or with compressed air or a mixture of the fluid, optionally additive and compressed air. In order to mix these different components as homogeneously as possible, a mixing device for mixing the fluid with the compressed air and/or the additive can preferably be provided, in particular a static mixer. In contrast to a pure line section, a static mixer has additional elements built into the line that influence the flow through the static mixer and thus lead to mixing. Such static mixers are known to those skilled in the art, so they do not need to be explained in more detail here. The mixing device is preferably arranged in the line system and in particular immediately upstream of the cleaning outlet. In this way, the components mentioned can be mixed homogeneously, which contributes to thorough cleaning.

In order to avoid contamination or clogging of the cleaning outlet, suitable filters can be arranged in the line system, in particular in the line system behind the fluid tank and/or the compressed air tank.

The control device can basically use any combination and/or sequence of fluid, in particular water and/or compressed air, with or without additive to act on the transparent element. For example, the control device can be designed to simultaneously apply a liquid fluid from the fluid tank and compressed air from the compressed air tank to the transparent element for cleaning. Additionally or alternatively, it can be provided that the control device is designed to apply a liquid fluid from the fluid tank and then with compressed air from the compressed air tank to the transparent element for cleaning. In this way, the liquid fluid is also removed from the transparent element by the compressed air, so that no fluid remaining on the transparent element changes the image information. In particular, it can then be provided that a reference image, as described above, is recorded. In principle, the control device can be designed to control the valve in such a way that the transparent element is subjected to a continuous stream or a pulsed stream of liquid fluid and/or compressed air from the fluid tank and/or the compressed air tank for cleaning. In addition, a time sequence of any selection and combination of all of the above-mentioned applications can be provided, for example first a pulsed application of liquid fluid from the fluid tank followed by a continuous application of compressed air or similar.

In order to ensure that the cleaning of the transparent element is actually successful, it is preferably provided that the control device is designed to carry out a new dirt detection after cleaning and to initiate a new cleaning of the transparent element if contamination is still detected. In this way, the cleaning is repeated until the desired result is achieved. For this purpose, for example, an original reference image created before cleaning began can be used. Alternatively, it can also be provided that after a certain number, for example 3, 4, or 5, unsuccessful cleaning attempts are aborted and, for example, a warning message is displayed for the operator. The display can also take place on the display device. In this case, either a defect can be assumed or the contamination of the transparent element cannot be removed by the cleaning system of the invention, so that cleaning by an operator is required.

In addition, one or more sensors, even different ones, can be provided and connected to the control device, which determine different states of the overall system and make their results available to the control device. For example, it can be provided that the control device comprises a fill level sensor on the fluid tank and/or a pressure sensor on the compressed air tank and/or a temperature sensor on the cleaning outlet and/or on the fluid tank and/or on the valve and/or on the pump and/or in the line system. In other words, the control device is connected to such sensors. It is designed in particular to monitor the sensor signals. It can also be used by the sensors Display states or the sensor signals on the display device to inform the operator. For example, warning signals can also be generated in this way if, for example, the fill level in the fluid tank and/or the pressure in the compressed air tank falls below a threshold value. Even if a component freezes, so that fluid or compressed air cannot be applied to the transparent element, a corresponding warning can be displayed for the operator. In particular, the sensor signal of the temperature sensor or sensors can also be used, for example, to control a heating device that heats up the corresponding components and in particular de-ices them.

In the case in which the ground milling machine has several cameras, the control device can be designed to initiate cleaning of the transparent element for each individual camera individually and independently of the others, for example if the transparent element is dirty based on the image information from this camera was determined. In addition, it can be provided that the operator specifically enters a control command to carry out cleaning on a specific camera. Alternatively, it can be provided that the cameras are divided into groups. For example, if several cameras are arranged in a functionally connected region of the machine, for example in the area of the transfer conveyor belt or below it, it can be assumed that these cameras are also exposed to similar contamination. It may therefore make sense to have the entire group cleaned if the transparent element of a camera in this group is found to be dirty. Finally, it can also be provided that all cameras are cleaned at the same time. Overall, the control device is therefore preferably designed to initiate cleaning of a single camera or of several cameras or of all cameras of the ground milling machine at the same time. A desired focus can therefore be set, either on ensuring that the transparent elements of the cameras are as clean as possible as a precaution or on the most targeted cleaning possible to save resources.

In the event that the ground milling machine has more than one camera, in particular at least three or more cameras, each with a cleaning device, it is particularly preferred that a master camera is defined in relation to the cleaning defined above and its triggering and the further cameras in With regard to the cleaning function, they are classified as slave cameras. This means that when cleaning depends on image information, only the image information from the master camera is taken into account. If it is determined for this camera or its image information that cleaning needs to be triggered, for example by exceeding a threshold value and/or for example via alternative paths, as described above, this is also assumed simultaneously for all slave cameras, so that these too getting cleaned. In this development, the image information of only one camera must be evaluated and at the same time all cameras can be cleaned as described above. The master camera is attached to the rest of the ground milling machine particularly preferably near the milling unit or near the discharge point of the transport device, as described above.

Finally, there may be internal or external circumstances that influence how well contamination comes off the transparent element. Internal circumstances can be, for example, the presence or use or absence of an additive for the cleaning fluid. External circumstances can be, for example, the weather or the composition of the soil worked. The control device can react to this as already described, for example by switching between continuous or pulsed loading of the transparent element. In addition, the control device is preferably designed to control the pump and/or the valve in order to set a flow volume of the cleaning outlet. In other words, the control device is designed to adapt the flow volume of the cleaning outlet to the prevailing conditions. If, for example, it is determined after cleaning that the transparent element is still dirty, the control device can react to this by increasing the flow volume of the cleaning outlet during the subsequent cleaning and thus intensifying the cleaning. On the other hand, if, for example, a control command from the operator is entered which activates the addition of an additive to the cleaning fluid, the control device can reduce the flow of the cleaning outlet, since the cleaning is already improved by the use of the additive, which means that fluid can be saved overall.

The problem mentioned at the beginning is also achieved with a method for cleaning a transparent element arranged in a recording area of a camera of a ground milling machine, which is in particular a ground milling machine according to the above statements. Accordingly, all of the explanations already made above regarding the features, effects and advantages of the ground milling machine, in particular regarding process steps, also apply in a figurative sense to the method according to the invention and vice versa. Reference is only made to the other statements to avoid repetition. Specifically, the method according to the invention comprises at least the steps: monitoring the contamination of the transparent element of the camera, detecting contamination of the transparent element depending on a working situation of the ground milling machine or depending on image information recorded by the camera, and applying liquid fluid and/or to the transparent element or compressed air from a fluid tank and/or a compressed air tank. The contamination is monitored in particular by monitoring the working situation of the ground milling machine and/or the image information, as described above. In particular, it can be provided that the control device is designed to carry out the method according to the invention. This means that the control device receives and evaluates the necessary control commands or data and the corresponding ones Controls components of the ground milling machine. For example, the control device is equipped with appropriate software for this purpose.

It can be provided for the method according to the invention that the detection of contamination of the transparent element as a function of image information recorded by the camera is carried out solely as a function of a master camera, the triggering of cleaning or the application of liquid fluid to the transparent element and/or or compressed air from a fluid tank and / or a compressed air tank, but depending on this, takes place for the master camera and at least one or more slave cameras.

Figur 1:

eine Seitenansicht einer Bodenfräsmaschine;

Figur 2:

ein erstes Ausführungsbeispiel eines Systems zum Reinigen eines transparenten Elementes einer Kamera;

Figur 3:

ein zweites Ausführungsbeispiel eines Systems zum Reinigen eines transparenten Elementes einer Kamera;

Figur 4:

ein drittes Ausführungsbeispiel eines Systems zum Reinigen eines transparenten Elementes einer Kamera;

Figur 5:

ein viertes Ausführungsbeispiel eines Systems zum Reinigen eines transparenten Elementes einer Kamera;

Figur 6:

ein fünftes Ausführungsbeispiel eines Systems zum Reinigen eines transparenten Elementes einer Kamera;

Figur 7:

ein Ablaufdiagramm des Verfahrens; und

Figur 8:

eine Kamera mit Aufnahmebereich und im Aufnahmebereich angeordnetem transparentem Element.

The invention is explained in more detail below using the exemplary embodiments shown in the figures. It shows schematically:

Figure 1:

a side view of a ground milling machine;

Figure 2:

a first embodiment of a system for cleaning a transparent element of a camera;

Figure 3:

a second embodiment of a system for cleaning a transparent element of a camera;

Figure 4:

a third embodiment of a system for cleaning a transparent element of a camera;

Figure 5:

a fourth embodiment of a system for cleaning a transparent element of a camera;

Figure 6:

a fifth embodiment of a system for cleaning a transparent element of a camera;

Figure 7:

a flowchart of the procedure; and

Figure 8:

a camera with a recording area and a transparent element arranged in the recording area.

Identical or identically acting components are numbered with the same reference numbers. Repetitive components are not designated separately in each figure.

The Figure 1 shows an example of a ground milling machine 1 according to the invention, specifically a road milling machine, here a cold milling machine of the center rotor type, also called a “large milling machine”. The ground milling machine 1 preferably has a machine frame 3 with an operator's cab 2. In the driver's cab 2 there are preferably controls with which an operator can control the ground milling machine 1 controls. The ground milling machine 1 preferably includes a drive motor 4, which can be, for example, an internal combustion engine, in particular a diesel engine, or one or more electric motors. When the ground milling machine 1 is in operation, it preferably moves in the working direction a over a ground 8 and processes it.

For this purpose, the ground milling machine 1 designed as a road milling machine points according to Figure 1 preferably driving devices 6, in the example shown chain drives, and in particular a milling drum 9 as a soil processing device. The milling drum 9 is preferably rotatably mounted in a milling drum box 7 about a rotation axis 10 aligned transversely to the working direction a. The milling drum 9 and the milling drum box 7 form a milling device. During operation, the milling drum 9 preferably removes soil material from the ground 8. From the milling drum box 7, this removed soil material is preferably transferred to a transfer conveyor belt 11, from which it is transported forward in the working direction a to a loading conveyor belt 5. The loading conveyor belt 5 in turn preferably transfers the removed soil material onto a transport vehicle (not shown) for removal.

The ground milling machine 1 shown also preferably has a water spray system 28. In the case of the ground milling machine 1 according to Figure 1 the water spray system 28 is preferably designed to spray the interior of the milling drum box 7, in particular the milling drum 9, and/or the milled ground material on the transfer conveyor belt 11 and/or on the loading conveyor belt 5 with water. This serves, on the one hand, to cool the milling drum 9 and to avoid dust. The water spray system 28 is connected in particular to the line system explained later and the associated pump and the water tank. In particular, the water spray system 28 is also supplied by these components.

The ground milling machine 1 comprises at least one and preferably a plurality of cameras 12. The cameras 12 can in principle be arranged at any position on the ground milling machine 1. They are preferably designed to record the external environment of the ground milling machine 1 and/or an external view of at least parts of the ground milling machine 1 or image information about it. For example, cameras 12 are provided which record the ground 8 immediately in front of and/or immediately behind the ground milling machine 1 and/or a milling device. For the ground milling machine 1 according to Figure 1 In addition, a camera 12 can be provided on the loading conveyor belt 5 in order to monitor the overloading process onto the transport vehicle. All cameras 12 are preferably connected to a control device 20, which can be part of the on-board computer of the ground milling machine 1 or is the on-board computer. The control device 20 preferably receives the signals from the cameras 12 and can in particular also process and/or evaluate them. In addition, it is preferred that the control device 20 is connected to a display device 24, for example a display or a screen in the driver's cab 2, via which the control device 20 provides information to the operator of the ground milling machine 1 can display. For example, the control device 20 can display the image information coming from the cameras 12 on the display device 24, so that the operator can use the corresponding views to make it easier to operate the ground milling machine 1 or for more precise control. Finally, the control device 20 preferably also includes a counter 27 with which the control device 20 can count various parameters relating to the working situation of the ground milling machine 1. For example, the counter 27 can be designed to count the number of machine starts or the number of transport vehicles loaded by the ground milling machine 1. The corresponding values can be used by the control device 20 as the working situation of the ground milling machine 1 to make an indirect conclusion about the quality of the image information provided by the cameras 12. In addition, the counter 27 can also be designed as a timer if time intervals are to be determined.

In Figure 8 a camera 12 is shown in more detail as an example of all cameras 12. The cameras 12 preferably include a recording area 13. The recording area 13 designates at least part of the space through which the camera 12 records images or image information. In the recording area 13 there is preferably at least one transparent element 37, which is, for example, the outermost lens or a transparent protection of the lens of the camera 12 (in Figure 8 shown as an example on the right in the recording area 13) or a viewing window in a housing protecting the camera 12 (in Figure 8 for example placed on the left in the recording area 13). In the present case, "the" transparent element 37 is preferably the transparent element in the recording area 13 which shields the camera 12 from the outside environment in such a way that dust and/or vapors that are present in the outside environment come into contact with the transparent element 37 can come into contact, but not with parts of the camera 12 lying behind the transparent element 37. When the ground milling machine 1 is in operation, it can therefore happen that dust and / or vapors from the construction site settle on the transparent element 37 and cloud it. This leads to a progressive deterioration of the image or the image information recorded by the camera 12. This problem is particularly pronounced at positions of the ground milling machine 1 where a large amount of dust is to be expected during operation, for example under, preferably directly under, the transfer conveyor belt 11. Here it can happen very quickly that the image information becomes worthless for the control device 20 or the operator.

In order to counteract this deterioration of the image information, a system is preferably provided for monitoring the contamination of the transparent element 37 of the cameras 12 and cleaning the transparent element 37 of at least that camera 12 in which contamination of the transparent element 37 is detected. Such systems are exemplified in the Figures 2-6 shown. They all include at least one fluid tank 14, for example a water tank and/or a compressed air tank 15. In addition, a line system 19 and in particular a pump 21 is preferably provided. The pump 21 is preferably designed to convey the fluid from the fluid tank 14. In particular, the pump 21 also supplies the water spray system 28 of the ground milling machine 1, if present, with fluid from the fluid tank 14. In the line system 19 downstream behind the fluid tank 14, a filter 16, for example a water filter, can be provided in order to avoid blockage of further components by possibly in the Fluid tank 14 to avoid existing contamination. For the same purpose, there is optionally an air filter 17 in the line system 19 downstream behind the compressed air tank 15. The filter 16 and the air filter 17 are in all embodiments Figures 2-6 shown, but one or both can just as easily be omitted. In addition, the systems shown include at least one cleaning outlet 22, for example a cleaning nozzle. The cleaning outlet 22 is designed to apply fluid from the fluid tank 14 and/or compressed air from the compressed air tank 15 to the transparent element 37 arranged in the recording area 13 of the camera 12. For this purpose, the cleaning outlet 22 is connected to the corresponding tanks via the line system 19. Fluid from the fluid tank 14 is conveyed in particular by the pump 21 to the cleaning outlet 23. Compressed air from the compressed air tank 15 in turn does not have to be conveyed itself, since the compressed air tank 15 is filled with compressed air in particular by a compressor, not shown. At least one valve 18 is preferably provided, via which the control device 20 can control the flow of fluid and/or compressed air to the cleaning outlet 22. In particular, the valve 18 or the valves 18 are also designed so that the control device 20 can adjust the flow volume as desired.

The specific features of the exemplary embodiments will be discussed below Figures 2-6 received. These differ from one another in individual aspects, while a large number of the features of the exemplary embodiments correspond to one another. The focus of the following description is therefore on the differences between the individual exemplary embodiments. Features of the exemplary embodiments that are not explicitly mentioned can therefore be provided exactly as in the other exemplary embodiments explained. The respective distinguishing features can also be used in exemplary embodiments other than those specifically shown. All of the features mentioned below can be combined with one another as long as they are not mutually exclusive.

In the exemplary embodiment according to Figure 2 A separate line system 19, a separate cleaning outlet 22 and a separate valve 18 are provided for the fluid from the fluid tank 14 and the compressed air from the compressed air tank 15. The control device 20 preferably controls both the pump 21 for conveying the fluid and all the valves 18. In this way, the inflow of fluid and compressed air is regulated separately and independently of one another. The transparent element 37 of the camera 12 is therefore supplied with cleaning fluid and compressed air separately from one another via separate cleaning outlets 22.

In Figure 3 An exemplary embodiment is shown in which fluid from the fluid tank 14 and compressed air from the compressed air tank 15 can be applied together via a common cleaning outlet 22 to the transparent element 37 of the camera 12 for cleaning. For this purpose, the line system 19 coming from the tanks is brought together in a valve 18, which has corresponding switching positions in order to direct either fluid or compressed air or both fluid and compressed air further to the cleaning outlet 22. This valve 18 is also preferably controlled by the control device 20, just like the pump 21. In particular, a single line of the line system 19 is arranged downstream of the valve 18, which conveys both fluid and compressed air when the valve 18 is in a corresponding switching position. In order to ensure the most homogeneous mixing of fluid and compressed air, a mixing device 23 can be provided at this point, upstream of the cleaning outlet 22. The mixing device 23 is designed, for example, as a static mixer. Static mixers include a line section in which additional flow-influencing internals are provided, which lead to a homogeneous mixing of the transported fluids. However, the mixing device 23 can also be omitted. In addition, the mixing device 23 can also be used in the other exemplary embodiments in which the fluid and the compressed air (and optionally an additive) are to be mixed, especially in the exemplary embodiments of Figures 5 , 6 and 7 . The mixture of fluid, for example water, and compressed air is then sprayed or sprayed onto the transparent element 37 of the camera 12 from the one common cleaning outlet 22.

The exemplary embodiment according to Figure 4 makes it clear how transparent elements 37 of several cameras 12 can be cleaned. For this purpose, the line system 19 is preferably divided in front of the cleaning outlets 22 assigned to the cameras 12, so that one cleaning outlet 22 per camera 12 is preferably connected to the valve 18. Although three cameras 12 are shown in the exemplary embodiment, more or fewer than three cameras 12 can also be provided. This is indicated by the dotted continuation of the line system 19. The control device 20 controls via the valve 18 whether fluid or compressed air or both should be directed to the cleaning outlets 22. A further valve 40 can be arranged in front of each cleaning outlet 22, which is preferably also controlled by the control device 20. By opening or closing the valves 40, the control device 20 controls which individual transparent elements 37 of the cameras 12 should be supplied with cleaning fluid and/or compressed air from the corresponding cleaning outlets 22. However, all valves 40 can also be omitted. In this case, the valve 18 not only decides whether fluid or compressed air should be used alone or in a mixture, but the transparent element 37 of the cameras 12 is also directly acted upon. In this case, all cameras 12 or their transparent elements 37 are cleaned at the same time. The valve 18 and/or the valves 40 can be designed to increase the flow volume regulate. Even if this is not explicitly shown, the other embodiments could also follow the principle of Figure 3 be designed to clean a large number of cameras 12 or their transparent elements 37.

In particular, it can happen when there are several cameras 12, such as in the Fig. 4 shown, it can be provided that only one camera is used as the master camera and, in particular its contamination, is decisive for triggering cleaning of several or all cameras (the remaining cameras 12 of the ground milling machine 1 affected by this are referred to as slave cameras). . Based on the exemplary embodiment in the Fig. 1 It is particularly preferred if one of the cameras arranged on the underside of the machine frame of the ground milling machine 1 or the camera arranged on the transport device 5 is the master camera.

In Figure 5 An exemplary embodiment is shown in which an additive tank 25 is provided. The additive tank 25 preferably contains an additive, for example a cleaning agent, which can preferably be mixed with the fluid of the fluid tank 14 before this mixture is applied to the transparent element 37 of a camera 12. The additive is, for example, a liquid, which is preferably introduced via a pump 26, for example a gear, piston, membrane or water jet pump, into a common part of the line system 19 with the fluid from the fluid tank 14. Although not shown, this embodiment is particularly suitable for use as in Figure 4 Mixing device 23 shown, which then also leads to a homogeneous mixing of the additive in the fluid. The outlet of the additive tank 25 is preferably provided with a valve 39. The valve 39 is in particular also controlled by the control device 20, for example depending on an input from an operator. The control device 20 can therefore determine by closing or opening the valve 39 whether additive gets from the additive tank 25 into the line system 19 and thus also to the cleaning outlet 22. The use of the additive can therefore optionally be activated or deactivated by the control device 20. Of course, the use of a corresponding additive can also be provided for in all other embodiments of the invention.

The exemplary embodiment in Figure 6 is intended to illustrate further modifications that are possible for all exemplary embodiments. For example, the pump 21 can be arranged not only upstream of the valve 18, as shown previously, but also downstream. A reference 29 is preferably arranged in the field of view of the camera 12, in particular in the viewing direction behind the transparent element 37 in the recording area 13 of the camera 12. The reference 29 can be, for example, a light source, a contour or a recognizable pattern. Since it is known how the reference 29 should be represented by the camera 12 in the image information when the transparent element 37 is clean, it can be concluded from the actual representation of the reference 29 in the recorded image information whether there is contamination of the transparent element 37 is present. In addition, various sensors can be provided, all of which are preferably connected to the control device 20. For example, a fill level sensor 30 can be provided on the fluid tank 14, which determines the fill level of the fluid tank 14 and passes on a corresponding value to the control device 20. Analogously, a pressure sensor 31 can be provided on the compressed air tank 15. The pressure sensor 31 is also connected to the control device 20 and forwards the measured value to it. In addition, a temperature sensor 32 can also be provided, for example. The temperature sensor 32 can be arranged at the cleaning outlet 22, as shown. Alternatively, the temperature sensor 32 could also be arranged on the line system 19, on the pump 21, on the valve 20 or on the fluid tank 14. Like the other sensors, the temperature sensor 32 is connected to the control device 20 and passes on the measured temperature values to it. Based on the measured signals, the control device 20 can, for example, issue warnings to an operator if, for example, the fill level or pressure has dropped too much and the tanks need to be refilled. In addition, a warning can be generated if the temperature sensor 32 detects freezing of one of the components mentioned.

Figure 7 Finally, a flowchart of the method 33 shows. The method includes monitoring 34 the contamination of the transparent element 37 of a camera 12. The monitoring 34 preferably relates to the transparent elements 37 of all cameras 12 provided on the ground milling machine 1. A further step includes detecting 35 one Contamination of the transparent element 37 or the transparent elements 37 depending on a working situation of the ground milling machine 1 or depending on image information recorded by the camera 12. In particular, if contamination is detected, this is followed by the application 36 of the transparent element 37 or the transparent elements 37 with fluid and/or compressed air from a fluid tank 14 and/or a compressed air tank 15. After the application 36, the method 33 begins again from the beginning, so that the contamination and the associated deterioration of the image information must be monitored further and continuously. Overall, the invention makes it possible to ensure consistently high quality of the image information provided by the cameras 12. At the same time, contamination of the transparent element 37 of a camera 12 is efficiently detected and eliminated.

Claims (11)

Soil milling machine (1) for processing a soil (8), in particular road milling machine, recycler or stabilizer, comprising - a machine frame (3) carried by driving devices (6, 38) with a driver's cab (2) for an operator, - a milling device, - at least one camera (12) for recording image information of an external environment and/or an external view of at least part of the ground milling machine (1), the camera (12) having a recording area (13) with a transparent element (37) through which through which it records the image information, - a control device (20) which receives the image information from the camera (12), - a fluid tank (14) with a cleaning fluid and/or a compressed air tank (15) which is connected to a line system (19), characterized,
that a cleaning outlet (22) is present, which is connected to the line system (19) via a valve (18) and/or fluid delivery device controlled by the control device (20) and is designed to clean the transparent element (37) with liquid fluid from the fluid tank (14) and/or compressed air from the compressed air tank (15), the control device (20) being designed to initiate cleaning of the transparent element (37) depending on a work situation or depending on the image information. Ground milling machine (1) according to claim 1,
characterized,
that the work situation - switching the ground milling machine (1) on or off, and/or - a start or end of a work operation, and/or - a start or end of a transport operation, and/or - lowering or raising a milling drum (9), and/or - a sequence of a time interval, for example related to an operation or a working operation of the ground milling machine (1), and/or - Reaching a distance, for example related to an operation or a working operation of the ground milling machine (1), and / or - reaching a threshold value of the weight or volume of soil material overloaded by the ground milling machine (1) onto a transport vehicle, and/or - Reaching a threshold value of a counter (27), for example a counter (27) for the number of machine starts or the transport vehicles loaded by the ground milling machine (1), and/or - a start or an end of an operation and/or a type of operation of a water spray system (28) for moistening the milling device and/or the removed soil material includes. Ground milling machine (1) according to one of the preceding claims,
characterized,
in that the control device (20) is designed to evaluate the image information as part of dirt detection and initiates cleaning of the transparent element (37) if the dirt detection detects that the transparent element (37) is dirty. Ground milling machine (1) according to claim 3,
characterized,
in that the control device (20) is designed to detect brightness and / or contrast and / or saturation and / or image sharpness and / or relative luminescence and / or pattern recognition in part of the image information or in the entire image information to draw on. Ground milling machine (1) according to one of claims 3 to 4,
characterized,
in that the control device (20) is designed to detect temporal changes in the image information and to detect contamination of the transparent element (37) when the changes exceed and/or fall below a threshold value. Ground milling machine (1) according to one of claims 3 to 5,
characterized,
in that the control device (20) is designed to use a reference (29) detected by the camera (12), for example a light source, a contour or a pattern, to detect dirt. Ground milling machine (1) according to one of claims 3 to 6,
characterized,
in that the control device (20) is designed to detect a change in parts of the image information, for example individual pixels, and to detect contamination of the transparent element (37) when the proportion of the changed image information exceeds a threshold value. Ground milling machine (1) according to one of claims 3 to 7,
characterized,
in that the control device (20) is designed to evaluate the image information for dirt detection using software based on machine learning. Ground milling machine (1) according to one of the preceding claims,
characterized,
that it includes at least one of the following features: - It comprises at least one and preferably a plurality of cameras (12); - It comprises a milling drum (9) rotatably mounted in a milling drum box (7) about an axis of rotation (10) for removing soil material; - It comprises a transfer conveyor belt (11) and a loading conveyor belt (5), the transfer conveyor belt (11) for transporting milled soil material from the milling roller box (7) to the loading conveyor belt (5) and the loading conveyor belt (5) for transporting the milled soil material onto a transport vehicle is designed, wherein the camera (12) is arranged between the transfer conveyor belt (11) and the floor (8); - It comprises a pump (21) connected to the line system (19) for transporting fluid from the fluid tank (14); - A cleaning outlet (22) is provided for each camera (12), with a pump (21) supplying this cleaning outlet (22) with fluid being provided for each cleaning outlet (22), or with one pump (21) being designed to supply all cleaning outlets (22) to supply fluid; - the cleaning outlet (22), preferably all cleaning outlets (22), and/or the fluid tank (14) is/are designed to be heatable; - The fluid for cleaning is provided with an additive, in particular a cleaning agent, the additive being mixed with the fluid in the fluid tank (14) or the additive being provided in a separate additive tank (25) and outside the fluid tank (14). the fluid of the fluid tank (14) is mixed; - A mixing device (23), in particular a static mixer, is provided for mixing the fluid with the compressed air and/or the additive. Ground milling machine (1) according to one of the preceding claims,
characterized,
that the control device (20) comprises at least one of the following features: - It is designed to simultaneously apply fluid from the fluid tank (14) and compressed air from the compressed air tank (15) to the transparent element (37) for cleaning; - It is designed to apply fluid from the fluid tank (14) and then compressed air from the compressed air tank (15) to the transparent element (37) for cleaning purposes; - It is designed to control the valve (18) in such a way that the transparent element (37) can be cleaned with a continuous stream or with a pulsed stream of fluid and/or compressed air from the fluid tank (14) and/or the compressed air tank (15) is applied; - It is designed to carry out a new dirt detection after cleaning and to initiate a new cleaning of the transparent element (37) if dirt is still detected; - It comprises a display device (24) arranged in the driver's cab (2) for displaying the image information; - It comprises a fill level sensor (30) on the fluid tank (14) and/or a pressure sensor (31) on the compressed air tank (15) and/or a temperature sensor (32) on the cleaning outlet (22), and is designed to monitor sensor signals and in particular on the display device (24); - It is designed to initiate cleaning of a single camera (12) or of several cameras (12) or of all cameras (12) of the ground milling machine (1) at the same time; - It is designed to control the pump (21) and/or the valve (18) in order to set a flow volume of the cleaning outlet (22). Method (33) for cleaning a transparent element (37) arranged in a recording area (13) of a camera (12) of a ground milling machine (1) according to one of the preceding claims, comprising the steps: - monitoring (34) the contamination of the transparent element (37) of the camera (12), - Detecting (35) contamination of the transparent element (37) depending on a working situation of the ground milling machine (1) or depending on image information recorded by the camera (12), and - Actuating (36) the transparent element (37) with fluid and/or compressed air from a fluid tank (14) and/or a compressed air tank (15).

Images