Abstract:
A robot tool for machining workpieces, includes a connecting element for connection to a robot. A cutting blade is maintained in a predetermined position by a retaining element, the retaining element being connectible to the robot by a connecting element.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority as a continuation application under 35 U.S.C. §120 to PCT/EP2008/006550, which was filed as an International Application on Aug. 8, 2008 designating the U.S., and which claims priority to German Application 10 2007 041 423.6 filed in Germany on Aug. 31, 2007, the entire contents of which are hereby incorporated by reference in their entireties. 
     
    
     FIELD 
       [0002]    The disclosure relates to robot tools for processing of workpieces, robot systems, and methods for processing of workpieces. 
       BACKGROUND INFORMATION 
       [0003]    Robot tools for processing of workpieces are known in a wide range of applications, for example for painting, welding or adhesive bonding. However, fields of application also exist in which the processing of workpieces is not carried out by robots but is coped with manually by appropriate personnel. 
         [0004]    For example, a protection projection beyond the boundary of a workpiece, for example a protective sheet which is adhesively bonded over an LCD display, may be removed manually with a sharp blade, such as by cutting it off manually with an appropriate knife. Knives such as these can become blunt comparatively quickly, and accordingly may frequently have to be replaced. Furthermore, there is an acute risk of injury in a situation in which the blades break off during the cutting process. 
       SUMMARY 
       [0005]    A robot tool is disclosed for processing a workpiece. An exemplary robot tool includes a first connecting element for connecting to a robot; a holding element, connected to the connecting element for holding a cutting blade in a predetermined position when the first connecting element is connected to the robot; and a gripping apparatus detachably connected to the holding element. 
         [0006]    A robot system is disclosed for processing a workpiece. An exemplary robot system includes a robot and a robot tool which includes a first connecting element for connecting to a robot; a holding element, connected to the connecting element, for holding a cutting blade in a predetermined position when the first connecting element is connected to the robot; and a gripping apparatus detachably connected to the holding element. 
         [0007]    An exemplary method for processing a workpiece using a robot tool connected to a robot, a cutting blade held in a predetermined position by a holding element, and a gripping apparatus connected to the holding element, includes holding a workpiece to be processed with the holding apparatus; moving the gripping apparatus to a predetermined position on a table; and moving the cutting blade along a predetermined movement path to process the workpiece. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The disclosure, advantageous refinements, improvements of the disclosure, and further advantages will be explained and described in more detail with reference to the exemplary embodiment which is illustrated in the drawing, in which: 
           [0009]    The single FIGURE shows an exemplary robot system. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    An exemplary robot tool, an exemplary robot system and an exemplary method for processing of workpieces, are disclosed herein by which processing can, for example, be carried out more quickly and more exactly than in the past. 
         [0011]    An exemplary robot tool as disclosed herein includes a cutting blade that can be held in a predetermined position (e.g., a position established by a user) by a holding element. The holding element can be connected to the robot by the connecting element. 
         [0012]    This can result in an exemplary robot tool which carries out exact cutting tasks, as part of workpiece processing. This is because, for example, the cutting blade can be held in a predetermined position and can be used in conjunction with the robot, with the accuracy of the robot movement. 
         [0013]    An exemplary robot tool as disclosed herein can have a cutting blade changer. 
         [0014]    This can ensure that any cutting blades which may have become blunt can be replaced in a simple manner, or can easily be replaced on a periodic basis (for example, after a certain usage time). 
         [0015]    An exemplary robot tool as disclosed herein can have a test apparatus for the cutting blades. 
         [0016]    This can allow the cutting blade which is currently in use to still be used while it is still of a predetermined sharpness. It can then be replaced as appropriate when, for example, the cutting blade is found to be unusable. 
         [0017]    An exemplary robot tool as disclosed herein can have the cutting blade connected in a sprung manner to the holding apparatus. 
         [0018]    This can advantageously result in tolerance compensation. If, for example, the sprung holder is acting in one spatial direction, then uneven features on a cutting edge or material thickness changes on the workpiece to be cut, or other unpredictable events, can be compensated for particularly easily. 
         [0019]    The cutting performance can be advantageously improved by having the cutting blade of an exemplary robot tool be a hot blade. 
         [0020]    An exemplary robot tool as disclosed herein includes a further connecting element that can be provided on the holding apparatus. 
         [0021]    This can result in the capability to integrate a further processing appliance with the holding apparatus, and thus on an exemplary robot tool. A further processing appliance such as this can be, for example, a second cutting blade with the advantage that a second cutting blade can be available particularly quickly when required. However, it is also feasible to connect other appliances or apparatuses, for example a suction apparatus or measurement apparatuses, without any problems. 
         [0022]    In an exemplary robot tool, a gripping apparatus can be connected, for example, detachably connected, to the holding element. 
         [0023]    An exemplary robot tool can use the gripping apparatus to first move the workpiece to be processed to a predetermined processing position and then, without any need for a second robot or even a tool change on the relevant robot, to start processing of the workpiece immediately. When, for example, the gripping apparatus is detachably connected to the holding element, the exemplary robot tool can leave the gripping apparatus on the workpiece. This allows the workpiece to be picked up again later in a particularly simple manner. 
         [0024]    In an exemplary robot tool, the holding element may have a sensor, such as an optical or laser-based sensor, or any other suitable sensor. 
         [0025]    This can allow the exemplary robot tool to use the sensor, for example a digital camera, to record an image of its environment and in this way to identify its environment by analysis of the image, in the process making it possible to take account of possible obstructions in the movement path. 
         [0026]    The sensor can also be used for verification purposes, at least by a previously predetermined reference point or a reference edge line, or the like on a workpiece to be processed or in the working area of the robot. 
         [0027]    A desired position and orientation of the workpiece can be processed to be determined or to be confirmed in a particularly simple manner. By way of example, verification can be carried out by searching for the reference point at an expected or planned point on the workpiece. If the reference point cannot be found there, search movements can be carried out around the expected position to search for the actual reference point, for example a marker that has been applied or a typical point on the workpiece. 
         [0028]    The sensor can measure the workpiece overall. Furthermore, the sensor can be used to identify the position and orientation of the workpiece and, if necessary, can be used to correct a movement programme for the robot, using the identified position and orientation. 
         [0029]    This can also allows slight discrepancies in the position of the workpieces in their workpiece holder to be corrected as desired, that is to say, for example, individually for the respective processing process. 
         [0030]    An exemplary robot system can include at least one of the exemplary robot tools according to the disclosure, and can achieve advantages mentioned above. 
         [0031]    An exemplary robot system can include a blade changer arranged in the working area of the robot, and an exemplary robot tool can interact with the blade changer when desired. 
         [0032]    An exemplary robot tool can be relieved of the function of blade replacement and can accordingly be made simpler. 
         [0033]    A corresponding situation applies to the design of an exemplary robot system with a blade tester, which can be arranged in the working area of the robot and interact with an exemplary robot tool as desired. 
         [0034]    An exemplary method for processing of workpieces using an exemplary robot tool can move a cutting blade along a predetermined movement path by an exemplary robot system. 
         [0035]    The exemplary method for processing of workpieces using a robot tool can achieve uniformity and repeatability of processing, and therefore a correspondingly high quality level. Furthermore, the cutting speed can be optimized as appropriate to the blades that are used, and this can lead to considerably better cutting performance. Furthermore, the working area of the robot can be a safety zone in which no operator may be located during operation of the robot. This therefore can preclude from the start the otherwise normal possibilities of injury or danger to people such as these. 
         [0036]    An exemplary method for processing of workpieces using a robot tool can use a sensor to determine a reference point for a starting point of the predetermined movement path. 
         [0037]    This can ensure verification of the predetermined movement path or correction of the predetermined movement path as appropriate for the individual position and orientation of the workpiece currently to be processed, in a particularly simple manner. 
         [0038]    In order to improve the cutting quality, an exemplary method for processing of workpieces using a robot tool can include testing the condition of the cutting blade before and/or after each cut (for example breakage, bending, etc). 
         [0039]    This can allow predetermined quality standards to be implemented in a particularly simple manner. 
         [0040]    The single FIGURE shows an exemplary robot system  10  with a robot  12 , a workpiece table  14  on which a workpiece  16  is arranged. In the illustrated example, the robot  12  has a robot foot  18  and a robot arm, such as a multi-axis robot arm  20  which is fitted with a combination tool  22  at its free end. In this example, the combination tool  22  can be firmly connected to a connecting element, such as a flange which can be attached and/or formed at a desired position of the robot arm  20 , so that the robot  12  determines both the spatial position and the alignment of the combination tool  22  by simple movement. 
         [0041]    The combination tool  22  is connected to the robot arm  20  by a holding element  24  for holding the tool in a predetermined position (e.g., a position established in advance by a user) when the connection flange is connected to the robot  12 . The holding element  24  can be used as a basic element for a blade holder  26  in which a blade  28  is clamped, for a sensor system  30  and for a suction gripping apparatus  32 . The holding element  24  can be firmly connected to all these components  26 ,  30 ,  32 . 
         [0042]    The combination tool  22  is illustrated in this FIGURE in such a way that the suction gripping apparatus  32  is arranged directly opposite the tool  16  to be processed, with this tool  16  having already been placed in a workpiece holder  34  on the tool table  14 , which is positioned on the ground. Furthermore, the suction gripping apparatus  32  is at a distance from the workpiece  16  in the illustrated FIGURE. A protective sheet  36  can be connected to a relevant side of the workpiece  16 , on the side of the workpiece  16  facing away from the workpiece table  14 . In this example, the workpiece  16  is intended to be a solar module which has been produced from an arrangement of a multiplicity of individual solar cells, with the protective sheet  36  being intended to be used as protection for the solar cells for other processing steps as well as for any subsequent transport. In the illustrated example, however, this protective sheet  36  is even larger than the relevant surface of the workpiece  16 , so that the task for the robot with its tool is to cut off the protective sheet along the edges bounding the surface, as close as possible to these edges. 
         [0043]    A blade tester  40  and a blade changer  42  are also shown on the ground alongside the tool table  14 , in a working area of the robot. This makes it possible for the robot  12  to check the condition of the cutting blade during the processing of the workpiece  16 , before or after, each processing operation on a workpiece, and if necessary, to carry out a blade replacement. It is also within the disclosure for appliances  40 ,  42  such as these to be arranged in an appropriately adapted form on the holding base element  24  of the combination tool  22  itself. This can avoid the need for the various robot arm movements which are desired in order to reach the blade tester  40  or the blade changer  42 . 
         [0044]    The example shows a cold blade. However, it is equally possible to use hot blades as well, as are known by those skilled in the art. This can increase the life of the blades. 
         [0045]    The example shows that the processing of the workpiece  16  by the combination tool  22  with the robot  20  and further components  40 ,  42 ,  14  relating to an exemplary robot system  10  ensures that workpieces can be processed particularly quickly and reliably. 
         [0046]    Using the illustrated robot system  10 , an exemplary method according to the disclosure for processing of the workpiece  16  can be carried out with the combination tool  22  as follows. First, the robot approaches a handover station for unprocessed workpieces. There, the suction gripping apparatus  32  is moved to a position above the next workpiece to be processed, to a similar position to that shown in this FIGURE, for example, immediately above one side of the workpiece which is fitted with the protective sheet. The FIGURE shows a side view of the suction gripping tool  32 , so that this view shows only a first and a second suction gripper  44 . One suction gripper can be adequate depending on the objective, the shape and the size of the workpiece, although a considerably greater number of suction grippers  44  can be desired. For example, six or more (or less) suction grippers  44  may be used in order to maintain a safe grip on a solar module, and also to transport it. The robot now moves the suction gripping apparatus  32  until the suction grippers  44  rest on the surface of the workpiece  16 . The suction grippers  44  are then operated so as to produce a suction effect, with the workpiece  16  adhering to the suction gripping apparatus. 
         [0047]    The robot can now move the workpiece  16  from the transfer position to a point above the tool table  14 . In a further robot movement, the workpiece  16  is placed in the holding apparatus  34  on the tool table  14 , and the suction effect of the suction gripping apparatus  32  is switched off, so that it is now decoupled or released from the workpiece  16 . 
         [0048]    By way of example, as an alternative to this procedure, a connecting element  46  between the suction gripping apparatus  32  and the base element  24  can be designed as a disengagable or operable coupling such that a robot controller or a tool controller decouples or uncouples the suction gripping apparatus  32  from the base element  22  as desired. For example, as soon as the workpiece  16  is positioned in the workpiece holder  34 , the suction gripping apparatus  32  remains on the workpiece as a result of the connection to the suction grippers  44  and the workpiece, with the complete suction gripping apparatus being completely decoupled by decoupling the coupling on the intermediate piece  46 . 
         [0049]    The robot tool  22  is now able to carry out further processing steps using different apparatuses. First the sensor system, for example a camera  30 , can be moved by an appropriate combination tool/robot movement to a position above the workpiece  16 , so that the sensor system can measure the entire workpiece. The exact position of the workpiece  16  in its workpiece holder  34  can be determined on the basis of the measurement points and, in addition, a reference point can be calculated and used to define, to correct and to verify the starting point of the cutting movement by the blade  28 , exactly and individually for this workpiece to be processed at that time, in its current position. 
         [0050]    The cutting blade  28  can first be moved to the blade tester  40  by a suitable change in the position of the combination tool  22 , where it is moved to a test position such that the appliance can test the blade. For example, it is assumed that the blade has been worn and that the robot now moves the combination tool  22  to the blade changer  42 , in which the blade is replaced. However, the sharpness test and/or the blade replacement can be carried out on appropriate appliances on the combination tool  22  itself, which is then designed appropriately. The robot moves the blade  28  to its starting position in the area close to the workpiece  16 . During this positioning, care is taken to ensure that the movement path of the blade  18  has a profile which is technically as optimum as possible for the cutting of the protective sheet  36 , so that the cutting speeds, cutting angles, and so forth are complied with. Comparatively minor disturbances in the movement process of the blade  18  which result, for example, from dimensional inaccuracies of the workpiece  16  on the edge to be cut, can be compensated for by an appropriate compensation apparatus. The blade can be mounted in a sprung (e.g., extended) manner, for example, in a compensation apparatus such as this, for example, at right angles to the cutting movement of the blade cutter. In the chosen example, the movement path for cutting the protective sheet  36  runs along the edges on which the protective sheet  36  projects beyond the workpiece  16  including four individual straight-line movement elements, so that, once these four movement elements have been completed, the process has moved around the edges once. 
         [0051]    After the end of the cutting process, the robot arm  20  of the combination tool  22  moves back to a position approximately above the workpiece  16 , in such a way that the sensor  30  can record a further image of the workpiece  16 . A quality check of the cut can be carried out by an appropriately designed image processing system and, if the cut quality is adequate, the workpiece  16  is picked up again by the suction gripping apparatus  22 , and is moved from the workpiece table  14  to a transfer position for processed workpieces. 
         [0052]    Thus, it will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein.