Abstract:
A method for the automated surface treatment, in particular grinding, of a profile component in the form of a profiled large component, in particular of a rotor blade of a wind turbine, with a treatment device comprising a moving gantry, a robotic system with a control system and a treatment tool of a tool head, comprising the steps of: moving the moving gantry as a moving carriage, generally free from any mechanical limitation, along a profile surface of the profile component, moving the treatment tool essentially transversely to the profile surface of the profile component by means of feed motion robotics that can be activated between the moving carriage and the treatment tool, areal treatment of the large component by the treatment tool, wherein movement of the moving gantry is driven by the control system, and feed motion of the treatment tool is driven by the feed motion robotics, as defined by a model of the profile surface of the profile component, wherein, a number of areal treatment strokes is performed on the large component.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The invention relates to a method for the automated surface treatment, in particular grinding, of a profile component in the form of a profiled large component, in particular of a rotor blade of a wind turbine, as well as to a respective treatment device and a treatment system along with the treatment device. 
         [0003]    2. Description of the Related Art 
         [0004]    Such a device and such a method are known from WO 2008077844 A1. The disadvantages of the method disclosed in WO 2008077844 A1 are the following:
       the grinding gantry runs on tracks and, therefore, cannot be transported to other manufacturing sites;   since the grinding heads can only be moved horizontally, the entire profile contour cannot be ground;   if the cross-section or the length of the rotor blade is increased, the entire gantry must be adjusted.       
 
         [0008]    The often complex and, depending on the type of the wind turbine, the variable profile of the large component can indeed be a problem, even in the case of a profiled large component of a wind turbine—as, for example, in the case of a rotor blade, but also, if applicable, in the case of another large component of the wind turbine, such as a spinner cover, a hub, a nacelle cover or a tower segment or the like. The profile of a rotor blade, for example, is complex and, depending on the wind turbine, may actually be subject to variations, the consequence of which might be that they cannot be treated with a comparably inflexible treatment device of the type described above. 
       BRIEF SUMMARY 
       [0009]    One or more embodiments of the invention are directed to a method and a device, which, with regard to prior art, are improved and which, may, address at least one of the problems described above. At least one alternative solution for a solution known in prior art shall be proposed. One embodiment of the invention provides a treatment and/or a treatment device and a method enabling more flexibility in the treatment and/or processing of profiled large components of a wind turbine. In addition, in one embodiment of the invention is directed to designing the device and the method for an efficient, yet precise, treatment and/or processing of the large component as possible. In addition, one embodiment is directed to a method and a device, by means of which an automated surface treatment of the large component can be performed in a comparably precise position and/or evenly by means of a treatment tool. 
         [0010]    One embodiment of the invention also introduces a treatment system including a treatment device as mentioned above, and with a retaining gantry connected so as to control the finishing device, in particular a pivoting device of the retaining gantry that can hold the profiled large component of a wind turbine such that it can rotate. 
         [0011]    In order to eliminate the above mentioned disadvantages, an embodiment of the invention provides for the grinding robot to be mounted to a moving carriage so that it can drive to any position of the rotor blade. 
         [0012]    It is realized that the efficient and exact guidance of the treatment tool is possible through the use of a freely movable moving carriage. According to one embodiment of the invention, the control system will drive movement of the moving gantry and feed motion robotics will drive feed motion of the treatment tool, as defined by a model of the profile surface of the profile component. 
         [0013]    In principle, an area means any flat or, in most cases, three-dimensionally curved, particularly complexly arched area pursuant to a profile surface, in particular a surface of the large component, in particular a complexly arched area such as the surface of a rotor blade. Thus, an areal treatment stroke may, in principle, comprise the treatment of a randomly arched area or line in space. 
         [0014]    This and other advantageous further embodiments of the invention can be inferred from the sub-claims and specify in detail advantageous options for realizing the design in the context of further embodiments while specifying further advantages. 
         [0015]    It has also turned out in particular that it has to be ensured—in particular prior to the areal treatment of a large component—that treatment strokes covering at least significant percentages of the area of the large component are performed as evenly as possible. In this context, a problem arises, since, on the one hand, in order to ensure more flexibility the movement of the moving gantry is generally free from any mechanical limitation, but, on the other hand, the moving and the guiding of the treatment tool have a visible impact on the quality of the treatments and/or processing of the profiled large component after all, so that they should, at the same time, be performed as exactly and evenly as possible. 
         [0016]    Preferably, wear to the treatment tool can be assessed between a first and a second treatment stroke. 
         [0017]    A treatment and/or processing can comprise for example surface finishing such as grinding, finishing, painting or the like. A treatment and/or processing of the large component, for example in the context of a general manufacturing process, may also go deeper into the large component, i.e., underneath its surface. This may, for example, comprise a treatment building the large component, such as the insertion of laminate layers or a similar layered construction of the large component (laminating). 
         [0018]    Preferably, the treatment tool shall be guided into a precise position and/or evenly over a large part of the area of the large component. Preferably, for exact positioning, the robotic system can be adjusted with regard to its position prior to the initiation of a treatment stroke to a fixed position, in particular, a real position of the treatment tool in relation to the large component can be adjusted to a virtual position of the treatment tool in relation to the model. In addition, a further embodiment recognized that, as soon as a treatment tool—between a first and a second treatment stroke that can be set at will (e.g., with regard to time, location or treatment system or the like)—is subject to wear and tear or the like during a longer lasting large-area treatment, the quality of the treatment will be directly impacted. It turns out, for example, that, in the case of a grinding process, wear to a grinding tool (such as a grinding roller or a grinding plate tool) directly impacts the quality of the treatment, due to the changing peripheral speed on the grinding surface of the grinding tool (in the case of tool mass rubbing off). 
         [0019]    The further embodiment specifies that a number of areal treatment strokes are performed on the large component and that wear to the treatment tool is assessed between a first and a second treatment stroke. 
         [0020]    Below, treatment shall mean, in principle, any treatment of a large component removing material as well as any treatment adding material and also any sole treatment measure as such, which essentially does not change the existing material of the profile component but, if need be, merely modifies it. Furthermore, treatment can mean any type of cutting or non-cutting treatment. 
         [0021]    Selecting a time to assess wear to the treatment tool between a first and a second treatment stroke can be determined in different ways. For example, it can be specified that, in the context of fixed cycles, e.g., after each treatment stroke set with regard to the treatment system (e.g., termination of a movement direction at a reverse point) an assessment of the treatment tool is performed, before the performance of the next treatment stroke. In the case of a grinding process, a rotor blade can, for example, be ground along its longitudinal axis, which would define a treatment stroke between two reverse points of the tool head, which could, for example, be at a blade root and at a blade tip, but terminal points of a shorter travel, which can be determined at will, may also limit a treatment stroke between two reverse points. Each grinding process performed on the rotor blade in longitudinal direction would then lead to a constant quality of the surface in the context of the grinding process. 
         [0022]    In an alternative version, a fixed assessment time can also be, for example in accordance with the empirical values of a grinding path or the operating time of the treatment tool which is suitable for the assessment thereof. If the values estimated for the grinding path or the operating time are too high—and if, as a consequence, a relatively significant change occurs in the treatment tool due to abrasive wear—this could lead to decreasing treatment quality. However, this could be prevented by adjusting the cycles, since, in general, such a process can be designed to be adaptive, so that characteristic maps characteristic of a specific treatment tool and a specific large profile component, such as a rotor blade, can be created in the course of performing the process. However it is especially preferable to assess wear to the treatment tool between a first and a second treatment stroke. 
         [0023]    Preferably, wear is assessed, with the assessment featuring the following steps:
       moving the treatment tool on a reference body after the first and before the second treatment stroke   measuring a pressure between the treatment tool and the reference body and/or   measuring a distance between the treatment tool and the reference body and/or   measuring another reference parameter between the treatment tool and the reference body.       
 
         [0028]    Preferably, a reference parameter between the treatment tool and a reference body can be determined after the first and the second treatment stroke. If in a comparison of a wear parameter determined on the basis of a reference parameter with a wear threshold value, the wear threshold value is exceeded, the treatment tool can be replaced or the treatment tool can be adjusted at the tool head, in particular in such a way that, in the second treatment stroke, the treatment values of the reference parameters remain the same as in the first treatment stroke. Thus, during the areal treatment of the large component, consistent surface quality of the profile is guaranteed for all treatment strokes. 
         [0029]    In particular, wear can be further assessed, with the assessment using the following steps:
       determining a wear pressure and/or wear distance or other wear parameter;   comparing the wear pressure with a pressure threshold value and/or the wear distance with a distance threshold value and/or other wear parameter with a wear threshold value.       
 
         [0032]    In addition, replacing and/or cleaning the treatment tool has proven to be advantageous if the pressure threshold value and/or distance threshold value is exceeded, in particular during and/or prior to the second treatment stroke. 
         [0033]    Preferably, the control parameter of the treatment tool on the basis of the wear pressure and/or wear distance and/or the other wear threshold value can also be adjusted during the second treatment stroke. 
         [0034]    In the context of an especially preferred further embodiment, a contour of the profile surface according to a virtual model of the profile surface of the profile component will be stored in the control system and the treatment tool will be guided along this contour. In the context of a further embodiment, storing a contour and/or profile surface as defined by a virtual model of the profile surface of the profile component in the control system has proven to be advantageous. Thus, on the one hand, extensive calculating time for the movement is kept to a minimum. On the other hand, this time can for example be invested in adaptive control of the feed motion, which in turn is decisive for the actual treatment quality. This leads, in particular, to a control system that is relatively effective in terms of calculating time. 
         [0035]    Preferably, the identifier of a virtual model of the profile surface of the profile component and/or of a contour in the control system derived from it will be compared with an identifying characteristic—which will specifically be installed on the profile component, but can, in principle, also be used at another workplace location or at a location accessible to the robotic system. The identifying characteristic can also comprise the function of the above mentioned fixed position for adjusting the position of the robotic system and may, but does not have to, be installed on the large component. In particular, the areal treatment of the large component with the treatment tool can only be performed if the identifier can be positively attributed to the identifying characteristic. Preferably, positive attribution will ensure that the contour and/or the virtual model of the profile surface of the profile component in the control system fits the profile component. To this end, an identification sensor is provided on the treatment device, in particular on the tool head, in order to read the identifying characteristic. Preferably, the identifying characteristic can be realized as a bar code, surface code or a similar simple identifying characteristic. A more complex data exchange during an authentication process can also be used as comparing process. In particular, a virtual model of the profile surface of the profile component and/or contour of the profile surface (e.g., a header of the profile surface) that has been completely or partially uploaded to the identification characteristic can also be, first of all, uploaded to the control system of the treatment device during the comparison or be completely or partially replaced and be used for the positive attribution. 
         [0036]    Especially preferably, non-inherent obstacles, in particular obstacles in the form of persons, are identified by the treatment device. This ensure that movement of the moving carriage intended to be generally free from any mechanical limitation and to be along a profile surface of the profile component and/or a work movement of the feed motion robotics does not cause any undesired damage to obstacles or persons. In particular, an identification sensor system can be designed to identify obstacles, in particular obstacles in the form of persons, in an immediate motion area of the moving gantry and/or the robotic system. 
         [0037]    Especially preferably, a contour along which the treatment tool is guided comprises a grid with points, in particular with points arranged on the longitudinal side of the profile surface—which can be attributed to the trajectory of a treatment stroke—and points facing each other—in particular reverse points for the tool head—which are relevant to limiting the treatment stroke of the treatment tool. 
         [0038]    Especially preferably, the large component, in particular a rotor blade, is held in a pivoting device of a retaining gantry connected in a controlling manner with the treatment device, wherein a contour, along which the treatment tool is guided, comprises a grid with points framed by reverse points assigned to the circumference of the profile surface—in particular reverse points for the tool head—onto which the treatment tool is placed after the large component has been turned around and prior to a treatment stroke. 
         [0039]    Especially preferably, movement of the moving gantry and feed motion of the treatment tool are performed with the performance being corrected by means of an adaptive algorithm. 
         [0040]    Especially preferably, the treatment tool is a grinding tool. The treatment tool is cleaned by blowing in pressurized air. 
         [0041]    In particular, one control parameter of the treatment tool is a peripheral speed of the tool, wherein the peripheral speed is adjusted in such a way that the peripheral speed is essentially the same during the first and the second treatment strokes. 
         [0042]    Preferably, a distance and/or a pressure and/or another treatment tool control parameter can be controlled, in particular in relation to the profiled large component, and in particular in a constant manner. 
         [0043]    Further details and advantages of the invention are disclosed in the exemplary embodiments according to the drawing. Exemplary embodiments of the invention will now be described below based on the drawing. This is not necessarily intended to illustrate the exemplary embodiments to scale, but where it serves as an explanation, the drawing is rather presented in a schematic and/or slightly distorted form. In regard to amendments to the templates which are directly recognizable from the drawing, we refer to the applicable prior art. In this context, it has to be considered that a large variety of modifications and changes regarding the form and the detail of an embodiment can be made without needing to deviate from the general idea of the invention. The features of the invention disclosed in the description, in the drawing and in the claims may be essential for the further embodiment of the invention individually as well as in any combination with each other. Furthermore, all combinations of at least two of the features disclosed in the description, the drawing and/or the claims fall within the scope of the invention. The general idea of the invention is not limited to the exact form or the detail of the preferred embodiment shown and described below, nor is it limited to subject matter which would be limited in comparison to the subject matter asserted in the claims. Within a specified range of dimension values, values within the specified limits shall also be disclosed and be able to be used and asserted at will as threshold values. Further advantages, features and details of the invention can be inferred from the following description of the preferred exemplary embodiments as well as from the drawing; the drawing shows in: 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0044]      FIG. 1  shows a preferred embodiment of a grinding device in a perspective top view, 
           [0045]      FIG. 2  shows a perspective view of the grinding head of the grinding device from  FIG. 1 , 
           [0046]      FIG. 3  shows a side view of the grinding head of the grinding device from  FIG. 1 , and 
           [0047]      FIG. 4  shows a bottom view of the moving carriage of the grinding device from  FIG. 1 , 
           [0048]      FIG. 5  shows a flow chart of a preferred embodiment of a treatment method in the form of a grinding method for a rotor blade of a wind turbine; 
           [0049]      FIG. 6  shows a schematic view of a treatment system comprising a treatment device and a pivoting device of a retaining gantry for a rotor blade of a wind turbine, to illustrate an especially preferred grinding process while also showing a schematic view of a preferred control concept for the treatment method. 
           [0050]      FIG. 7  shows a diagram (A) and a flow chart (B) of a preferred assessment method for determining wear to the treatment tool between a first and a second treatment stroke if the treatment tool is designed as a grinding tool. 
       
    
    
     DETAILED DESCRIPTION 
       [0051]    The device for grinding rotor blades for wind turbines illustrated in  FIG. 1  includes a grinding robot  2  that includes an arm. A grinding head  1  is attached to the arm. The grinding robot  2  and a suction container  3  are mounted to a moving carriage  4 . For reasons of work safety, the whole device is edged with a protective cover  6 , so no employees enter the carriage during operation. The moving carriage  4  can be steered in any direction by a remote control, which can also be designed as a radio remote control. The grinding head  1  is mounted to the head of the grinding robot  2  so that it can rotate relative to the grinding robot  2 . 
       Basic Design: 
       [0052]    The treatment system, presently designed as a grinding machine, comprises three components (i) the robot  2  including a grinding head  1 , which is mounted on a moving carriage  4 , (ii) the moving carriage  4  with control of the robot  2  and the suction device  21  for the dust from the grinding unit and all power electronics, and (iii) a pivoting device of a retaining gantry, in this case a blade support  7 , for the rotor blade. 
         [0053]    Generally, in the installation, the robot can also be partially guided on tracks; however, preferably it is designed to be freely movable. The moving carriage  4  can be coupled with the control cabinet or one control cabinet by a cable. Preferably, the control cabinet will serve to consolidate and monitor the safety device and, respectively, bring the robot  2  or the moving carriage  4  to a standstill in case of danger. 
         [0054]    Preferably, this control cabinet will be mounted directly on the moving carriage  4 . A compressor unit, designed to control all mechanics in the robot  2 , is also mounted on the moving carriage. 
         [0055]      FIG. 2  shows a perspective view of the grinding head  1 . The grinding head is mounted to the robot arm adapter  23  so that it can rotate. The grinding roller with the grinding tool  20  is located in the grinding head  1 . The grinding roller protrudes from the grinding roller housing  24 . The suction device  21  is installed in the lower area of the grinding roller housing  24 . The suction device serves to move the dust created during the grinding into the suction container  3 . To this end, the suction device  21  is connected to the suction container by a hose. 
         [0056]    Regarding the design of the tool head, in this example designed as a grinding head: 
         [0057]    The treatment tool, which, in this example is designed as a grinding roller, is installed to be movable within the grinding head  1  so that it can move forwards or backwards. The roller itself is adjusted back and forth by a valve and a lever arm. During this, contact pressure is to be kept constant, which is carried out in this example by an adaptive control. Contact pressure can be controlled by the mechanical system and can be set with proportional valves. This means that if the contact pressure becomes too strong—i.e., the contour has changed in some way—the pressure in the proportional valve will also increase and the grinding carriage will be moved back accordingly. If, for example, more than one distance threshold value of 5 cm from the radius of the grinding roller is worn, the grinding roller will be replaced; for wear distances below this, it may not be possible to adjust the grinding roller. 
         [0058]      FIG. 3  shows a side view of the grinding head  1 . The grinding roller is driven by a motor  31  and a drive belt  33 . Alternatively, the drive belt can also be designed as a chain drive. The grinding roller housing  24  is moved by a pneumatic cylinder  32 . The pneumatic cylinder is connected via the grinding head pivot drive. 
         [0059]      FIG. 4  shows a bottom view of the moving carriage  4 . The moving carriage is driven by the drive  40 . The moving carriage is steered via steerable rollers  41 . The drive and the control are powered by the energy storage system  42 . 
         [0060]      FIG. 5  shows the process of a grinding method according to a preferred embodiment: 
         [0061]    In the initial position, the rotor blade is positioned at POS-P in step S 1  and the grinding robot is positioned at POS-R in step S 2 . In step S 3 , the grinding robot determines a relative position reIPOS, in this example by scanning the rotor blade, i.e., its position in relation to the rotor blade, three times. 
         [0062]    In step S 4 , the grinding program is run on the basis of this determined position reIPOS; namely a synchronized first and second grinding program PV, PA for the moving carriage  4  and the feed motion robots, in this example the robot arm and the grinding head. In step S 02 , the contour CONTOUR is already stored in the program for the grinding robot. Thus, in this case, no automatic scanning of the profile takes place, but the positions for starting up and grinding have been fed into the program as defined by a model MODEL in step S 01 . Accordingly, the surface of the rotor blade is ground in a zigzag shape. After each grinding procedure, split in a manner reasonable in terms of the work, and in this document referred to as a treatment stroke, wear to the grinding head is determined. 
         [0063]      FIG. 6  shows the schematic view of an embodiment of a breakdown of treatment strokes. 
         [0064]    The contours CONTOUR, or the coordinates of the contours CONTOUR, are stored in the robot program PA, PV. The individual points Pi of this contour CONTOUR are derived from the computer model MODEL of the rotor blade; preferably automatically, and if applicable also manually. If a new rotor blade has to be adapted to, the computer model and the contour CONTOUR based on it are adjusted accordingly. Automatic adjustment of the computer model MODEL and the robot program CONTOUR of the robot is generally possible, but, depending on the complexity, the adjustment may also be performed manually in a separate design process. 
       Positioning of the Robot in Relation to the Rotor Blade: 
       [0065]    The rotor blade  5  is clamped into a preferably  110 ° pivoting device  50  of a retaining gantry, so that it can be approached from each side. In principle, a pivoting device  50  designed to pivot the rotor blade about its axis at a rotation angle up to a certain value can be provided. In principle, the range of the rotation angle may be chosen at will and so that it is suitable with regard to the reach of the robot. Preferably, the range of the rotation angle comprises rotation angles at least up to and/or above 90°, especially preferably up to 110° (in accordance with the above mentioned preferred 110° pivoting device), preferably also up to 180°. 
         [0066]    Depending on the treatment state, a suitable rotation angle can be selected for a specific position of the rotor blade and then be changed for another position. During grinding, the rotor blade  5  constantly remains in one position. The grinding robot  2 , i.e., the moving carriage, moves, while pressing the grinding head  1  to the rotor blade, from the blade root  5 . 1  to the blade tip  5 . 2  and grinds one side or one contour of the rotor blade. To this end, reverse points Ug 1 , Ug 2  close to the blade root  5 . 1  and the blade tip  5 . 2  for longer trajectories Tg, but also reverse points Uk 1 , Uk 2  for shorter trajectories Tk are possible and, depending on the geometry of the profile, reasonable. Once the robot has reached the end of a treatment stroke, i.e., of the rotor blade at the reverse points Ug 1 , Ug 2  or in between at reverse points Uk 1 , Uk 2  located in between, it moves back and sends a signal that the rotor blade  5  can be pivoted further to a certain position by the pivoting device  50 . This may performed manually as well as, preferably, automatically; to this end, a communication channel  52  is installed accordingly between the robot  2  and the 110° pivoting device of a retaining gantry. If the robot  2  communicates that it has completed a treatment stroke, the rotor blade  5  will be pivoted into another position and then will once again move automatically along this trajectory Tg, Tk of the contour. 
         [0000]    The coordinate Systems: 
         [0067]    The rotor blade  5  has a fixed coordinate system just as the robot  2  does at POS-P or POS-R. By determining the position reIPOS of the rotor blade  5  in relation to the robot  2 , the difference between these two coordinate systems is determined. Thus, once the robot  2  knows in which position reIPOS it is in relation to the rotor blade  5 , it moves along the individual points of the contour and thus grinds the rotor blade  5 . An exact adjustment of the rotor blade  5  to the grinding robot  2  is therefore reasonable; the grinding robot  2  is movable and, thus, the grinding robot  2  is adjusted to the rotor blade  5 . The distance between the grinding robot and the rotor blade can vary, but does not have to vary; the contact pressure or the compensation of smaller obstacles can be closely adjusted by the above mentioned adaptive control and in accordance with the program PA. 
         [0068]      FIG. 7  shows in (A) a diagram of a test bench for determining wear to a treatment head and in (B) a flow chart for assessing wear to the treatment tool between a first and a second treatment stroke. To this end, in the first step P 1 , the tool head is located at a position POS. 
         [0069]    In order to determine wear to the grinding head  1 , the robot  2  moves the grinding head  1  on a reference body  60 , in this example on a plate, in step P 2 . Using an integrated measuring system  70  in a pressure cylinder of the robot  2 , preferably on the tool head, or—as in this example—directly on the treatment tool, the wear is determined. The grinding head  1  is slowly pressed to the plate and—using the pressure p and the distance d determined by the measuring system in step P 3 —the amount of wear ABN on the roller is assessed in step P 4 . If it is found in step P 5  that a wear distance d of more than the distance threshold value of 5 cm from the radius of the grinding roller is worn, the grinding roller should be replaced in step P 6 . 
         [0070]    The frequency of wear assessments may vary. A time-controlled manual assessment is conceivable, as well as an assessment based on how often the contour was traced or how many treatment strokes there were after the assessment. This can also depend on the frequency of readjustment options in step P 7  as long as there is a wear distance d of less than a distance threshold value of 5 cm. 
         [0071]    The grinding tool can be a commercially available grinding tool as well as a pressure cylinder. 
         [0072]    In addition, a device for cleaning the grinding head is provided, where pressurized air is blown into the grinding space to remove any dust from the grinding roller. Cleaning may also be performed manually, but preferably cleaning is also time-controlled or controlled based on grinding instances. 
         [0073]    It turns out that, advantageously, the concept is designed to indirectly make allowance for the peripheral speed of the grinding roller to provide a clean grinding pattern. If possible, the peripheral speed should be kept constant for all treatment strokes, e.g., at a three- or four-digit rpm value. Since the circumference of the grinding tool changes as the duration of the grinding process increases, it is specified that, preferably, the peripheral speed be adjusted accordingly or that the grinding tool or equivalent treatment tool be replaced or readjusted. The peripheral speed is preferably adjusted every time after wear to is measured, as illustrated in  FIG. 7  (A, B).