Patent Publication Number: US-2020282588-A1

Title: Hand-held power tool having a bearing arrangement

Description:
The invention relates to a hand-held power tool for machining a workpiece, comprising a drive motor, a tool holder, which can be driven by the drive motor, and which is for a working tool for machining the workpiece, and a guide element having a guide surface for guiding the hand-held power tool on the workpiece in a working direction, wherein the tool holder is mounted via a bearing arrangement such that it moves relative to the guide element and said tool holder can be driven by a servo motor arrangement, wherein the hand-held power tool can be swivelled via the bearing arrangement about at least one adjusting swivel axis passing through the guide surface at an angle, in particular at a right angle, for the relative adjustment of the tool holder relative to the guide element, wherein the hand-held power tool has a control device for controlling the servo motor arrangement. 
     Such a hand-held power tool is described in US 2015/0094836 A1. The hand-held power tool is a router that shows the operator the working area on the image, so to speak, wherein the operator themselves provides the feed motion. The operator guides the hand-held power tool along the surface of the workpiece, wherein the bearing arrangement and the servo motor arrangement control the tool holder to follow a working line or working area to machine the workpiece, such as to make a milling groove. The bearing arrangement comprises controlling kinematics with two eccentric bearings, but is not suitable for all types of hand-held power tools. 
     To solve the task, in a hand-held power tool of the type mentioned above, the control device for actuating the servo motor arrangement is designed in such a way that the servo motor arrangement adjusts the tool holder with respect to the guide element while maintaining a pivot position with respect to the adjusting swivel axis with a direction of motion component parallel to the guide surface of the guide element with respect to the guide element. 
     The control device has, for example, a control arrangement or control for such control of the servo motor arrangement. 
     It is expedient for the hand-held power tool to have one or more operating handles for an operator to grasp. It is preferably provided that the hand-held power tool has at least one operating handle for adjusting the guide element in the working direction or against the working direction, wherein the servo motor arrangement and the bearing arrangement are arranged between the tool holder and the at least one operating handle. For example, the at least one operating handle is located on the guide element. The at least one operating handle comprises for example a handle, a handling projection, an operating surface or the like. The bearing arrangement and the servo motor arrangement position the tool holder relative to the operating handle in order to keep the working tool in the correct position relative to the working area, in particular relative to a working line. The operator, on the other hand, ensures that the working tool is fed along the working direction or against the working direction. Thus, the operator moves the working tool back and forth in the working direction, as it were, by exerting force on the hand-held power tool at the at least one operating handle, while the servo motor arrangement and the bearing arrangement position the working tool. 
     It is a basic principle of the present invention that the control device together with the servo motor arrangement and the bearing arrangement ensure that the tool holder is not only adjusted with respect to its working angle, i.e. assumes a different angle of adjustment with respect to the guide element, but rather that the tool holder is additionally adjusted with respect to the guide element with at least one direction of motion component parallel to the guide surface, while maintaining a respective pivot position around the adjustment swivel axis. This adjustment is therefore a translational or shifting adjustment. The degree of freedom of movement of the movement direction component is therefore a translational or shifting degree of freedom of movement. Thus, for example, a kind of parallel adjustment of the tool holder can be set or controlled by the control device while maintaining the angle of adjustment. Thus, for example, if the operator adjusts the guide element, e.g. a saw bench or similar other guide element, transversely to the actual direction of motion, e.g. at right angles transversely or obliquely transversely, the control device controls the servo motor arrangement for adjustment of the tool holder parallel to the guide element in such a way that the angularity of the working tool relative to a working line remains the same not only at the incision area in the working tool but also in the extension thereof and/or relative to a working length of the working tool which is in engagement with the tool. 
     For example, a saw blade or similar other cutting blade suitable as a working tool can be adjusted by the control device and the control motor arrangement in such a way that the angularity of the entire blade relative to an e.g. straight working line and/or relative to a length of the working tool currently engaging or dipping into the workpiece is maintained. 
     The control device controls the servo motor arrangement advantageously in such a way that the working tool maintains its position, namely its angular position and/or longitudinal position, relative to a longitudinal length with which it cuts into the workpiece, even if the guide element is adjusted relative to the tool holder by the operator. 
     It is expedient for the working tool to have a front penetration area for penetration of the workpiece relative to the working direction. The penetration area includes, for example, a tooth arrangement or other cutting edge that cuts into the workpiece. The control device is designed to control the servo motor arrangement in such a way that the penetration area maintains a relative position relative to the working direction during a swivel movement of the tool holder about the adjusting axis and/or a movement with the movement direction component parallel to the guide surface of the guide element. Consequently, this measure ensures that the penetration area of the working tool does not move any feed motion in the direction of work, if the servo motor arrangement, as it were, corrects an unsuitable or undesired movement of the guide element by adjusting the guide element and the tool holder relatively about the adjusting swivel axis or by driving relatively with the movement direction component parallel to the guide surface of the guide element. In this connection, it is expedient that the penetration area only undergoes a feed motion or also a negative feed motion, as it were, i.e. a retraction or a return movement against the working direction, if the operator actually specifies this by a corresponding operating action on the guide element by moving the guide element forwards or backwards relative to the working direction. Thus, if the operator does not actuate the guide element forwards or backwards in the working direction, the penetration area of the working tool into the workpiece remains in place, as it were, while the actuation of the control device causes the servo motor arrangement to adjust the guide element and the tool holder relative to each other relative to the angle of adjustment relative to the adjusting swivel axis and/or relative to the movement direction component parallel to the guide surface of the guide element. 
     The control device is advantageously configured to adjust the tool holder relative to the guide element in such a way that the tool holder maintains its angular position relative to the, for example, linear working direction when the guide element is adjusted relative to the tool holder transversely to the working direction and/or at an angle to the working direction. The tool holder itself is therefore held in the correct position even if the guide element is adjusted by the operator, but this does not correspond to the “desired” working direction. 
     The control device is expediently configured to adjust the tool holder relative to the guide element in such a way that the tool holder maintains its relative position relative to an at least two-dimensional, preferably three-dimensional, coordinates system which is independent of a workpiece marker provided on the workpiece. For example, the coordinates system is provided by coordinates sensors that send corresponding reference information. Thus, the control device ensures that the tool holder is aligned relative to this external coordinates system, so to speak. An operating action of the operator in that they adjust the guide element, for example transversely to the working direction or set it at an angle, which in itself does not make sense, is corrected automatically, so to speak, by the control device. 
     The adjusting swivel axis can be a fixed axis relative to the guide element. For example, there is a corresponding swivel bearing between the guide element and the tool holder, which encloses or defines the adjusting swivel axis. 
     However, it is preferable that the adjusting swivel axis is not stationary relative to the guide element. For example, the adjusting swivel axis can be linearly adjustable and/or swivel about another swivel axis. 
     The servo motor arrangement may comprise several servo motors, for example a first and a second servo motor or at least a second servo motor. It is advantageous, for example, if the servo motor arrangement has only two, namely a first and a second servo motor. 
     One embodiment may provide that the servo motor arrangement comprises only linear drives, for example a first and a second linear drive. However, it is also possible that the servo motor arrangement has or comprises one or more rotary drives or combinations of rotary drives and linear drives. 
     The servo motor arrangement and/or the bearing arrangement are advantageously arranged within or above a projection surface of the guide element on the workpiece to be machined. The advantage of this is that the servo motor arrangement does not, so to speak, project laterally beyond the projection surface of the guide element, or only to an insignificant extent. In particular, it is preferable if the servo motor arrangement and/or the bearing arrangement are arranged completely within or above the projection surface of the guide element. 
     One embodiment of the invention may advantageously provide that the servo motor arrangement and/or the bearing arrangement does not project laterally in front of the guide surface of the guide element. The advantage of this design is that the bearing arrangement or the servo motor arrangement does not interfere with the operation, i.e. the operator can, for example, guide the guide element along the workpiece without a component of the servo motor arrangement or bearing arrangement getting stuck on an obstacle, so to speak. 
     Bearing concepts in which linear bearings are provided are explained below. A linear bearing could also be described as a sliding bearing that allows an exclusively translational sliding movement or a sliding movement along a linear displacement path. 
     The bearing arrangement should expediently have a first linear bearing and at least one second linear bearing. It is also possible that only a first and a second linear bearing or at least one further linear bearing is provided. 
     A respective linear bearing is used for linear adjustment of the tool holder relative to the guide element, in particular for linear adjustment of the tool holder transverse to the working direction. It is also possible for a linear bearing to extend essentially along the working direction. 
     The first and second linear bearings have adjusting axes that are parallel to each other. The bearing axes of the linear bearings can be parallel to each other in at least one position of the linear bearings. The adjusting axes can also be essentially parallel to each other, i.e. slightly inclined at an angle of 0° to 5°, for example. A linear bearing can, for example, be swivelled so that the bearing axes of the linear bearings are at an angle, in particular a small angle deviating from the parallel position, when the linear bearings are swivelled relative to one another, for example by means of one or more of the rotary bearings described below. 
     At this point it should be noted that at least one linear bearing can also be swivelled on a swivel bearing or a swivellable bearing receptacle. 
     However, it is advantageous if at least one linear bearing is stationary relative to a drive unit or the tool holder so that its adjusting axis extends, for example, along the working direction. 
     On the guide element there are, for example, fixed bearing receptacles for the first and/or the second linear bearing, on which a respective bearing element of the respective linear bearing is linearly displaceably mounted. The bearing element can be a driven component or a passive, so to speak carried component. 
     It is preferred when a respective bearing element is formed by the final control element of a linear drive, for example. The bearing receptacle can be provided on a stator of a servo motor, for example. 
     It is advisable for the bearing arrangement to comprise at least two linear bearings whose bearing axes are oriented transverse to the working direction. For example, the bearing axes can run essentially at right angles to the working direction. At this point it should be noted that the bearing axes can also have several angularities transverse to the working direction, e.g. if a respective linear bearing is swivellably mounted on a swivel bearing. 
     It is preferable if the bearing arrangement has as few degrees of rotational freedom as possible. One embodiment of the invention may provide that the bearing arrangement has a maximum of two, in particular a maximum of three rotary bearings. 
     One exemplary embodiment shown in the drawing shows that the bearing arrangement has at least or exactly three rotary bearings and at least or exactly two linear bearings, in particular exclusively three rotary bearings and two linear bearings. A linear bearing is preferably mounted rotatably or swivellably on the guide element using one of the rotary bearings. 
     However, embodiments are possible in which the bearing arrangement has two linear bearings and three rotary bearings or swivel bearings. It is advantageous if one of the swivel bearings or rotary bearings is located between two linear bearings and connects them together. The bearing elements of the linear bearings, for example, are connected to each other in a swivelling manner by the rotary bearing, in particular at their longitudinal end areas. 
     It is preferred if the bearing arrangement has, relative to the working direction, a bearing arranged in front of the tool holder, for example a rotary bearing and/or at least one linear bearing, and a bearing arranged behind the tool holder relative to the working direction, for example also a rotary bearing and/or a linear bearing. However, it is also possible, for example, for one bearing to be located, so to speak, at the height of the tool holder relative to the working direction, while the other bearing is provided behind or in front of it in the working direction between the guide element and the tool holder. 
     Furthermore, it is possible that the bearing arrangement has bearings arranged exclusively relative to the working direction in front of or exclusively relative to the working direction behind the tool holder, for example rotary bearings, linear bearings or the like. 
     It is expedient to mount the tool holder on a drive unit of the hand-held power tool with the drive motor. The drive unit is movably mounted relative to the guide element by means of the bearing arrangement. The servo motor arrangement is advantageously located between the drive unit and the guide element. With this embodiment it is possible that one angle of the tool holder remains the same. In this connection, the relative position of the tool holder and the drive motor is not changed, except for a change in the rotational angle or linear position of the tool holder relative to the drive motor caused by the drive motor. 
     In the above embodiment as well as in the following embodiment, it is advantageous if a gear, for example a planetary gear, a manual gear, an angle gear or the like, is provided between the drive motor and the tool holder. However, it is also possible for the drive motor to drive the tool holder directly, i.e. without an intermediate gear. 
     A further embodiment of the invention may provide that the tool holder is adjusted by the servo motor arrangement and the bearing arrangement relative to the guide element, while the drive unit is stationary relative to the guide element. For this purpose, a corresponding rotary coupling or motion coupling between the drive motor and the tool holder is provided, for example, by means of a flexible rotary shaft, an angle gear or the like. A bevel gear would be conceivable, for example. 
     In an embodiment of the invention, the working tool may, for example, be a milling tool, a grinding tool or the like. Another embodiment of the invention, which is shown in more detail in the drawing, provides that the working tool is or comprises a cutting tool with a flattened shape, for example a saw blade, a cutting disc or the like. Furthermore, the drive motor can, for example, drive a rod-like cutting tool, in particular if the hand-held power tool is configured as a jigsaw. 
     The drive motor is expediently arranged and/or configured to drive the tool holder in rotation. It would naturally be possible for the drive of the tool holder or the drive motor also to perform an oscillatory drive movement. For example, an oscillating gear can be provided between the tool holder and the drive motor. 
     The control device is suitably designed to control the servo motor arrangement for parallel adjustment of the cutting tool relative to the guide element in a plane parallel to the flat side of the cutting tool. Thus, for example, the cutting tool can be adjusted parallel to its flat side, wherein the above-mentioned angle of adjustment between the tool holder and the guide element is maintained. 
     It is preferable if the hand-held power tool has a display device for indicating an adjustment range of the tool holder and/or the working tool arranged on the tool holder, which can be set by the servo motor arrangement transverse to the working direction. For example, the operator can check that the tool holder or working tool is still within an adjustment range that can be adjusted by the servo motor arrangement. If this adjustment range is exceeded, the desired workpiece machining is no longer possible. 
     Furthermore, it is expedient if the hand-held power tool has a display device for displaying the actual position, set by the servo motor arrangement, of the tool holder and/or of the working tool arranged on the tool holder and/or for displaying a target position to be set of the tool holder and/or of the working tool arranged on the tool holder. In this way, the operator can check that the tool holder or the working tool or both are in the desired actual position. Furthermore, by displaying the target position of the tool holder or working tool, the operator can see which setting the servo motor arrangement will, so to speak, soon execute. 
     In an expedient embodiment of the invention, the hand-held power tool forms part of the system for machining a workpiece described below and is suitable for use in a process in which the system is used. A marker detection device is provided for detecting coordinate data of at least one workpiece marker of the workpiece. The hand-held power tool has guide means for guiding the working tool along the workpiece according to the coordinate data of the at least one workpiece marker. The system provides that the marker detection device has an optical and/or mechanical reference which can be positioned on and/or directly next to the at least one workpiece marker, 
     that the marker detection device is designed for determining the coordinate data of the at least one workpiece marker relative to an at least two-dimensional coordinates system which is independent from the workpiece marker, 
     and that the guide means of the hand-held power tool is adapted to guide the working tool with respect to the at least two-dimensional coordinates system in a working area which is geometrically defined by working area data determined on the basis of the coordinate data of the at least one workpiece marker. 
     In this respect, the basic principle is that the mechanical or optical reference is positioned, so to speak, directly on and immediately next to the at least one workpiece marker, so that in this way an exact spatial or local coincidence between the mechanical/optical reference on the one hand and the workpiece marker on the other hand can be achieved. A possible inaccuracy in that an optical system is used which maps the workpiece marker, so to speak, so that the user sets a virtual reference to the mapped workpiece marker is therefore not provided, unlike in the prior art. 
     The workpiece marker can be a marker that an operator applies to the workpiece, such as a linear marker, a line marker, a dot marker or the like. However, the workpiece marker can also be a natural workpiece marker, so to speak, or a workpiece marker which forms an integral part of the workpiece, for example a workpiece edge, a recess, a coloured marker or contrast marker in a surface coating of the workpiece or the like. 
     The coordinates system can be two-dimensional or three-dimensional. Therefore, the coordinates system is preferably spatial. 
     For example, the coordinates system is fixed relative to the working space. 
     A preferred exemplary embodiment provides that the hand-held power tool and/or the marker detection device and/or a workpiece position detection device explained later has a local coordinates system, in particular a local two-dimensional or three-dimensional coordinates system. At least one of the aforementioned components is designed to convert coordinate data of a geometric object determined in a local coordinates system, for example a point, a line or a surface, into another coordinates system. To this end, the following formulae (1), (2) and (3) are suitable for a rotational transformation. 
     
       
         
           
             
               
                 
                   
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     For example, a rotation about the X-axis by an angle a can be described with formula (1), a rotation about the Y-axis with the angle β can be described with formula (2), and a rotation about the Z-axis with the angle γ can be described with formula (3). Naturally, translational transformations are also possible, for which common matrix shifts are known to be suitable. 
     An alternative concept for calculating a shift operation or translation of points from one coordinates system to another coordinates system, for example from a local coordinates system of the marker detection device or the hand-held power tool to the global coordinates system related to the working space, are so-called quaternions. By means of scalar multiplications of the quaternions, for example, the coordinates systems can be converted into each other, so to speak. 
     The conversion or transfer of the coordinates systems can be performed by the respective control devices or monitoring devices of the marker detection device, the hand-held power tool, in particular the guide means, or a workpiece detection device which can be attached to the workpiece, for example. 
     At least one component of the system, which is formed by the hand-held power tool, for example its control device, and/or by the marker detection device and/or by a workpiece position detection device positioned or positionable on the workpiece, is advantageously configured for a translation and/or conversion of coordinate data of at least one point from a local, in particular two-dimensional or three-dimensional, coordinates system relative to the respective component into the at least two-dimensional, in particular stationary, coordinates system and/or vice versa relative to the working space. 
     The coordinates system can be located directly on the workpiece, for example by a marker strip with a geometric pattern. 
     It is preferable to provide the at least two-dimensional, preferably three-dimensional, coordinates system by means of at least one coordinates sensor which can be placed in a working space in which the workpiece is arranged. The guide means and/or the marker detection device are designed to determine the position of the at least one coordinates sensor and/or to determine at least one piece of reference information transmitted by the at least one coordinates sensor. The coordinates sensor can thus be arranged stationary, in a manner of speaking, at a predetermined position in the working space and/or on the workpiece, which is then detected by the marker detection device and preferably later also by the guide means when the workpiece is being machined. 
     The at least one coordinates sensor can be a so-called passive coordinates sensor, whose spatial position can be detected by the marker detection device and/or the guide means. For example, the marker detection device or the guide means detects a geometric contour and/or a color and/or a contrast, for example a bar code, on the at least one coordinates sensor. 
     The coordinates sensor can also be an active coordinates sensor that sends reference information. The reference information is for example optical information, such as light pulses, light waves or the like. In particular, physical waves, microwaves or the like are preferably provided as reference information. 
     The at least one coordinates sensor may have fastening means, such as adhesive fastening means, hook fastening means and/or suction fastening means, for attachment to the workpiece or a substrate, or both. Thus, the coordinates sensor can be fixed, so to speak. Furthermore, it is advantageous if the coordinates sensor has at least one utility surface for placement on a base or the workpiece or both. Preferably, a system with several, for example two, coordinates sensors is preferred. This enables a particularly favorable geometric configuration. The various coordinates sensors may be spaced so that the guide means or the marker detection device, or both, always have at least one coordinates sensor in their detection area. Furthermore, geometric methods for determining the two-dimensional or three-dimensional coordinates system, e.g. triangulation or the like, can also be used with several coordinates sensors. 
     The at least one coordinates sensor is expediently designed to transmit reference information in mutually angular directions and/or in mutually parallel planes. The marker detection device or guide means is designed to detect this reference information. This means that the marker detection device can make optimum use of the reference information. The directions that are at an angle to each other are preferably at right angles. For example, the coordinates sensor can transmit in parallel planes in a first direction and in a direction angled to the first direction. For example, a kind of stripe structure can be sent. The stripe patterns can be sent at an angle to each other, so that in principle a grid structure is specified by the coordinates sensor, wherein the individual grid lines can be sent simultaneously or consecutively. 
     It is also possible that the system works without such a coordinates sensor. For example, it may be provided that the guide means of the hand-held power tool or the marker detection device or both have orientation means for orientation relative to the at least two-dimensional coordinates system in a working space in which the workpiece is located. The orientation means are designed to detect geometric contours of the working space, for example walls, room corners, inner room edges or the like. It is also advantageous if the orientation means are designed to receive reference information characterising the position of the hand-held power tool or marker detection device or the workpiece in the working space. For example, the orientation means can be used to record the reference information mentioned above. 
     The marker detection device is preferably designed to detect the coordinate data of the at least one workpiece marker after the reference has been positioned relative to the workpiece marker according to at least one triggering condition. This means that the operator can, for example, position the optical or mechanical reference first relative to, for example, at least one workpiece marker or the respective workpiece markers. The marker detection device then records the coordinate data of the at least one workpiece marker according to at least one triggering condition. 
     There are various possible triggering conditions, which may also be in combination with each other. Below are some exemplary possibilities: 
     For example, a sensor may be provided on the marker detection device and/or the guide means which can detect an operator action such as a wiping movement, pressure or the like. The sensor can be an optical sensor, a capacitive sensor, an inductive sensor or similar. It is also possible that the controlling action by an electrical switch provided on the marker detection device or guide means or hand-held power tool is detected by the marker detection device or guide means. 
     Furthermore, a time condition, e.g. a dwell time of the reference of at least one workpiece marker for a predetermined time, is possible. The time condition can mean, for example, that the marker detection device is not moved relative to the workpiece marker for a predetermined time. A relative movement or even the lack of a relative movement can be determined by the marker detection device, for example by means of a distance measurement or an optical detection of the workpiece marker for a predetermined time, but also by means of the motion sensor explained below. 
     It is possible that the marker detection device has a motion sensor. If there is no movement of the marker detection device for a predetermined time, this is considered to be a detection of the workpiece marker. 
     In addition, the marker detection device and/or the guide means may comprise or include a distance sensor enabling the detection of a distance between the reference and the at least one workpiece marker. If a predetermined limit distance between the reference and the at least one workpiece marker is undershot, i.e. a limit distance is maintained, the workpiece marker is considered to be detected. 
     Furthermore, a dynamic detection of the workpiece marker is also possible. For example, the marker detection device can be moved over the workpiece marker and visually detect it. Optical detection includes, for example, a light-dark contrast between the workpiece marker and a background or surface of the workpiece. 
     Furthermore, it is advantageous if the marker detection device is designed for tactical and/or optical selection of the at least one workpiece marker. For example, the marker detection device may have a mechanical reference in the form of an arrow marker, a line marker or the like. The mechanical reference can also be provided to the hand-held power tool, for example by a side edge of the guide element, such as a guide carriage or guide bench. In terms of optical selection, for example, a directed light beam is possible. For example, a light source, in particular a laser or the like, may be provided on board the marker detection device. If this laser or other light source is directed at and coincides with the workpiece marker, the workpiece marker is considered to be detected. For example, an operator action is also useful for this purpose, i.e. the operator presses a key on the marker detection device to activate the coincidence between the optical reference, in particular the light beam, and the workpiece marker as a triggering condition for coordinate detection. This has already been explained above in connection with the advantageous triggering condition. 
     The following measure represents an intrinsically independent invention, but it can also be an advantageous embodiment of the above invention. The marker detection device may be a component which is separate or can be separated from the hand-held power tool. 
     In particular, the marker detection device is much lighter than the hand-held power tool. For example, it is only about 10-20% of the weight of the hand-held power tool. 
     Furthermore, it is advantageous if the marker detection device has a smaller spatial extent than the hand-held power tool, for example only 10-20% of the spatial extent of the hand-held power tool in at least one dimension, for example a transverse width, transverse length or the like, or in several dimensions. For example, the marker detection device can be significantly smaller than the hand-held power tool in two dimensions, in particular in cross-section. However, it is possible that it may also have approximately the same length or height as the hand-held power tool, for example if the marker detection device is pin-shaped or rod-shaped. 
     It is also possible for the marker detection device to form part of the power tool, for example by placing the reference on the guide element. The determination of the coordinate data in connection with the selection of the workpiece marker can also be performed directly by the hand-held power tool if it has the marker detection device on board. 
     The hand-held power tool expediently has a wired or wireless interface, or both, for the marker detection device. The marker detection device can transmit the coordinate data of at least one workpiece marker to the hand-held power tool via the respective interface, for example via Bluetooth, WLAN or the like. However, a wired transmission of these coordinate data is also possible, for example by means of serial data, bus data or the like. In particular, the provision of a bus interface or a bus transmission with a digital protocol, for example via Bluetooth, an I2C bus or similar, between the marker detection device and the hand-held power tool is possible. 
     The hand-held power tool may have a holding fixture for holding the marker detection device. For example, a pocket, recess or other similar holding fixture may be provided for the marker detection device. However, it is also possible that the hand-held power tool has a clamp or other similar support or holding fixture for the marker detection device. The holding fixture is provided for example on a machine housing of the hand-held power tool. For example, the machine housing accommodates the drive motor and the tool holder. The holding fixture can also be provided on the guide element. 
     The marker detection device is expediently motorless or has no drive motor to drive a working tool. Consequently, the marker detection device is, so to speak, a manually actuated or manually operated device, while the motor component of the system is provided by the hand-held power tool. A drive motor is comparatively heavy, which determines the weight of the hand-held power tool. The marker detection device, on the other hand, can form or have a light and therefore easily manageable unit. 
     When detecting the workpiece marker, it is in any case advantageous if the marker detection device is not or cannot be motor-driven. For example, the hand-held power tool itself may have or display the marker detection device. However, operation of the hand-held power tool is not provided, at least during the detection of the workpiece marker. It may be advantageously provided that the hand-held power tool blocks operation of the drive motor when detecting the workpiece marker. In any case, vibrations or similar other influences of the drive motor do not interfere if the marker detection device is not motor-driven at least during the detection of the at least one workpiece marker. 
     The marker detection device may include a pin or be pin-shaped. Therefore, the detection device is preferably designed in the manner of a pointing device. The reference is preferably formed by a tip or longitudinal end of the pin or pin-shaped marker device. 
     It is also possible that the marker detection device has an optical light source to provide the optical reference, such as a laser beam. In this context it is also advantageous if a distance measurement is provided. If, for example, the optical light source does not exceed a specified limit distance to the workpiece marker, the detection of the coordinates or coordinate data is enabled, so to speak. The light source must therefore be close to the workpiece marker so that the coordinate detection is actively switched relative to the at least two-dimensional coordinates system. 
     It is possible that the guide means actively guides the tool holder, so to speak, or even output only auxiliary information for the operator for optimum guiding of the tool holder and thus of the working tool. 
     For example, the guide means may include an output device for the visual and/or audible output to the operator of default information concerning or defining the working area, such as a target working line. The working area can also have a spatial shape such that it defines a work surface, for example. This work surface or working area can also be displayed on the output device. The output device is, for example, a display, in particular an LCD display, a graphics-capable display or the like. 
     The guide means advantageously comprise a servo motor arrangement with at least one servo motor for adjusting a relative position of the tool holder relative to the guide element. The at least one servo motor is for example an electric motor, a pneumatic drive or the like. Consequently, the guide means can, so to speak, adjust the tool holder, in particular the drive motor including the tool holder, relative to the guide element, so that the tool holder and thus the working tool follow a target working line or a target working area, so to speak. This means that the working area is automatically maintained or regulated, so to speak. 
     As already mentioned, the working area preferably comprises a working line along which the working tool is to be guided relative to the workpiece. It is also possible that the working area includes or is formed by a machining area of the workpiece intended for machining the workpiece. 
     It is preferable if the guide means and/or the marker detection device is designed to determine the working area data of the working area, for example to an at least sectionally straight working line or a complete working line extending between the workpiece markers, on the basis of coordinate data, related to the at least two-dimensional coordinates system, of at least two workpiece markers arranged at a distance from each other. For example, two line markers or dot markers can be provided on the workpiece. The marker detection device or the guide means can evaluate their position, so to speak, relative to the two-dimensional coordinates system and determine a working line from this. If several such workpiece markers are present, an interpolation is preferably possible in order to create a virtual straight working line. However, it is also possible for several workpiece markers to be read in, as it were, or for their coordinate data to be determined by the marker detection device in order subsequently to determine, for example, a working line or the like having angular sections and/or curvatures and/or curved lines by the guide means or the marker detection device. The system is therefore capable of determining the working area data itself, so to speak. 
     The guide means or the marker detection device, or both, may expediently have a receiving interface for receiving default data defining the working area, such as a working line. For example, a USB interface, a WLAN interface, a Bluetooth interface or the like is provided as a receiving interface to receive such default data. The default data is received, for example, from a CAD device, a computer or the like. Furthermore, the guide means and/or the marker detection device are designed to determine the working area data of the working area according to the default data. For example, the guide means or the marker detection device align the working area as a function of the at least one detected workpiece marker and/or define a starting point for the working area. 
     It is preferable if the system for the detection of a respective position of the marker detection device and/or the hand-held power tool comprises at least one coordinate detection device which can be placed in the working space in which the workpiece is arranged and which forms an assembly unit separate from the hand-held power tool or the reference of the marker detection device. The coordinate detection device may, for example, be an arrangement of one or more cameras, in particular a stereo camera or a plurality of stereo cameras. The coordinate detection device detects, so to speak, the position of the reference to be aligned with the workpiece marker or the hand-held power tool or both. For example, the coordinate detection device can form part of the marker detection device. 
     In the above scenarios, it has primarily been assumed that the workpiece remains in place after the workpiece marker or markers have been detected, i.e. the spatial or local position of the workpiece relative to the two-dimensional or three-dimensional coordinates system is maintained. The coordinate data of at least one workpiece marker therefore remain unchanged until the workpiece is processed. 
     However, the above measures can also be applied in connection with the subsequent embodiment of the invention, in which the workpiece does not have to remain stationary after the detection of the at least one workpiece marker, but is moved before the workpiece is machined, for example, is turned around, is moved to a more favourable machining location or the like. 
     Specifically, the system expediently includes a tracking means for tracking a movement of the workpiece after the detection of the at least one workpiece marker by the marker detection device up to a machining position intended for the machining of the workpiece by the hand-held power tool. The tracking means are designed to provide tracking data characterising this movement or the machining position, so that the guide means of the hand-held power tool guide or can guide the working tool on the basis of working area data determined from the coordinate data of at least one workpiece marker and the tracking data. For example, a translation of the coordinate data of at least one workpiece marker can be carried out using the tracking data, so that a new position of the workpiece marker can be determined, comprising transformed coordinate data, so to speak. The coordinate data of the workpiece marker are thus, so to speak, converted or further tracked according to the new position of the workpiece relative to the at least two-dimensional coordinates system. 
     The tracking can now be performed, for example, using the above-mentioned coordinate detection device, for example a stereo camera, which can be placed in the working space. This can, for example, record the position of the workpiece present when the at least one workpiece marker is detected and then a position of the workpiece relative to the at least two-dimensional coordinates system assumed before machining by the hand-held power tool. 
     However, the following measure is particularly convenient, in which it is provided that these comprise at least one workpiece position detection device and/or workpiece position reference marker attached to the workpiece after detection of the at least one workpiece marker and at least until reaching the machining position. The workpiece position detection device can be an active component which, for example, also detects the reference information of one or a plurality of coordinates sensors mentioned above. However, it is also possible that a workpiece position reference marker, for example a workpiece marker or similar other marker is attached to the workpiece, which is, so to speak, tracked by the tracking means. For example, in one scenario, the workpiece position reference marker is a workpiece edge of the workpiece that serves as the workpiece position reference marker. However, a workpiece position reference marker may also be provided which includes adhesive means, such as suction means, adhesives or the like, for attachment to the workpiece. This workpiece position reference marker has, for example, a colour contrast, light-dark contrast or the like, which can be detected by the tracking means. 
     It is also possible that a plurality of device reference markers and/or sensors for determining the orientation in the at least two-dimensional coordinates system are expediently arranged on the marker detection device and/or the hand-held power tool and/or the workpiece position detection device already mentioned. The device reference markers can, for example, be detected by a camera located in the working space. 
     The following measure contributes to a geometrically exact determination of coordinates. At least two device reference markers or at least two sensors for determining the orientation in the at least two-dimensional coordinates system are arranged on the marker detection device and/or the hand-held power tool at extremities or end regions or both of the respective marker detection device or hand-held power tool which are remote from one another. Furthermore, it is advantageous if the distance of the device reference markers or sensors corresponds to at least two thirds or at least half of a respective extension length of the hand-held power tool or the marker detection device. Thus, for example, if a machine has a height H, the sensors or device reference markers are positioned at a distance relative to this height that corresponds to half the height or one third of the height. 
    
    
     
       Exemplary embodiments of the invention are explained below using the drawing, wherein: 
         FIG. 1  shows a perspective oblique view comprising a system with a hand-held power tool as well as two coordinates sensors and a workpiece prior to workpiece machining, 
         FIG. 2  shows the system as shown in  FIG. 1 , but during workpiece machining by the hand-held power tool, 
         FIG. 3  shows a detail view of a coordinates sensor of the system as shown in  FIG. 1 , 
         FIG. 4  shows another system with marker detection devices that have a display and a reference marker, 
         FIG. 5  shows a schematic top view of the workpiece as shown in  FIG. 1  and the hand-held power tool as shown in  FIG. 1  during workpiece machining, wherein a display device is schematically represented, 
         FIG. 6  shows a schematic top view of movement kinematics of a hand-held power tool of the type shown in  FIGS. 1, 2 and 4  with a first servo motor arrangement and a first bearing arrangement, 
         FIG. 7  shows the hand-held power tool as shown in  FIG. 6  in a first relative position of the tool holder and guide element, 
         FIG. 8  shows the hand-held power tool as shown in  FIGS. 6 and 7  in a second relative position of the tool holder and guide element, 
         FIG. 9  shows a further embodiment of a hand-held power tool with a different bearing concept and a different servo motor arrangement, in a basic position, 
         FIG. 10  shows the hand-held power tool as shown in  FIG. 9  in a first adjusting position, 
         FIG. 11  shows the hand-held power tool as shown in  FIGS. 9 and 10  in a second adjusting position, 
         FIG. 12  shows a further bearing arrangement and servo motor arrangement of a hand-held power tool in a schematic representation, 
         FIG. 13  shows the control device of the hand-held power tools as shown in the above drawings in schematic representation, 
         FIG. 14  shows a modification of the system as shown in  FIG. 1 , wherein the workpiece to be machined is arranged in a first position in the working space, 
         FIG. 15  shows the arrangement according to  FIG. 14 , wherein the workpiece to be machined is arranged in a second position in the working space, and 
         FIG. 16  shows a schematic representation of a marker detection device as shown in  FIG. 1 , and 
         FIG. 17  shows a system with a hand-held power tool having a camera, and 
         FIG. 18  shows the system shown in  FIG. 1 , but with a plurality of local coordinates systems. 
     
    
    
     A hand-held power tool  20  of a system as shown in  FIG. 1  has a machine housing  21  which houses a drive motor  22 . The drive motor  22  can be switched on and off by a switch  23 . An operator may press the switch  23 , for example. The drive motor  22  is used to drive a tool holder  24  so that it rotates about an axis of rotation D. A gear  22 A can be provided between the drive motor  22  and the tool holder  24 . 
     The working tool  25  can be detachably attached to the tool holder  24 , for example by means of a screw, a bayonet joint or the like. The working tool  25  is in this case a cutting tool  25 A. The working tool  25  has a disc-like or leaf-like shape. For example, the working tool  25  is a saw blade. 
     The hand-held power tool  20  is a sawing machine, in particular a plunge sawing machine or the like. The hand-held power tool  20  is preferably intended for woodworking, wherein other materials can also be machined, such as plastics, metal or the like. 
     The working tool  25  is arranged so to speak on one longitudinal side of the hand-held power tool  20 . Its flat side  26  is essentially free standing, so that with the hand-held power tool  20  it is possible to saw close to the edge, so to speak. 
     The hand-held power tool  20  is an electric hand-held power tool, wherein the concept according to the invention is also applicable to hand-held power tools with pneumatic drives, i.e. pneumatic drives for the tool holder and thus the working tool. 
     For the electrical power supply of the hand-held power tool  20 , a power supply cable  28 A can be provided ( FIG. 2 ) with which the hand-held power tool  20  can be connected to a power supply network, for example an alternating current network. For example, a power plug  28 B is provided on the power supply cable  28 A for plugging into a power outlet. However, a more mobile or off-grid concept is preferred, in which the hand-held power tool  20  already has an on-board energy storage device  28 , for example a battery pack or similar. 
     The drive motor  22 , if applicable the gear  22 A, and the working tool  25  are components of a drive unit  29  of the hand-held power tool  20 . An interface for the energy storage device  28  is arranged on this drive unit  29 , i.e. the energy storage device  28  is arranged on the drive unit  29 . However, a so-called guide bench or guide plate could also be arranged on the guide element  30  explained below, for example. 
     The guide element  30  has a guide surface  31  on its side facing away from the drive unit  29 , in particular the underside, which can be guided along a workpiece W, for example its upper side. The guide surface  31  is a flat surface in this case. However, for a hand-held power tool according to the invention, a non-planar guide surface, such as a curved or bent guide surface, may also be provided. 
     In this case, the guide element  30  is plate-like or has a guide plate or is designed as such. For example, the guide element  30  is substantially rectangular. The guide element  30  has a front transverse side  32  in the working direction, a rear transverse side  33  in the working direction and longitudinal sides  34  and  35  extending between these transverse sides  32 ,  33 . The working tool  25  is arranged in the area of the right longitudinal side  35  in the working direction and projects downwards in front of the guide surface  31  in at least one depth adjusting position which is suitable for machining the workpiece W. 
     The drive unit  29  is adjustably mounted relative to the guide element  30  by means of a bearing arrangement  40 . This means that the tool holder  24 , and if necessary the working tool  25 , are also mounted so that they can be adjusted relative to the guide element  30  by means of the bearing arrangement  40 , e.g. swivellable, slidable or both. 
     At this point it should be noted that the drive motor  22 , possibly a gear, are components of the drive unit  29 , which as a whole is adjustably mounted relative to the guide element  30  by means of the bearing arrangement  40 . However, if the drive motor  22  was fixed to the guide element  30 , the power of the drive motor  22  could be transmitted to the tool holder  24  by means of a power transmission device, for example a flexible shaft. 
     The bearing arrangement  40  comprises a depth adjustment bearing  36 , with which the tool holder  24  is mounted so that it can be adjusted between at least two deep adjusting positions relative to the guide surface  31 . In the present case, the depth adjustment bearing  36  comprises, for example, a swivel bearing at the front or rear in the working direction. For example, the hand-held power tool  20  is designed in the manner of a plunge saw. When the tool holder  24  is adjusted by swivelling the drive unit  29  about a depth adjusting axis T of the depth adjustment bearing  36 , the tool holder  24  can, for example, be adjusted from an upper depth adjusting position in which the working tool  25  does not project in front of the guide surface  31 , and at least one lower depth adjusting position, preferably several lower depth adjusting positions, in which the working tool  25  projects in front of the guide surface  31  to machine the workpiece W. Instead of a swivel bearing, however, a sliding bearing or sliding bearing arrangement could also be provided to provide the depth adjustment bearing  36 . 
     Furthermore, it is possible to swivel the tool holder  24  and thus the working tool  25 , which may be located on the tool holder  24 , about a mitre axis G which extends parallel to the working direction AR and/or parallel to the longitudinal side  35  of the guide element  30 . Thus, diagonal cuts into the workpiece B are possible without any problems. The mitre bearing  37  comprises for example two partial mitre bearings  37 A,  37 B, which are arranged in the working direction AR in front of and behind the tool holder  24 , in particular the working tool  25 . The depth adjustment bearing  36  and the mitre bearing  37  can be operated manually. For example, in a manner known per se, they comprise fixing elements which are released in order to adjust the drive unit  29  relative to the depth adjusting axis T and/or the mitre axis G relative to the guide element  30 . 
     The bearing arrangement  40 , however, still includes bearings that cannot be adjusted by hand but by motor. In this connection, various bearing concepts are shown in  FIGS. 6 to 12 , which are explained below as examples: 
     A bearing arrangement  40  in the embodiment shown in  FIGS. 6, 7 and 8  comprises, for example, linear bearings  41 ,  42 , which are arranged in the working direction AR in front of and behind the tool holder  24 . Linear bearings  41 ,  42  are coupled to the drive unit  29  using swivel bearings  43 ,  44 . The rotary bearing  43  is directly coupled to the drive unit  29 , for example by means of the machine housing  21 . The rotary bearing  44  on the other hand is coupled to the drive unit  29  by means of a further linear bearing  45 . The rotary bearings  43 ,  44  have axes of rotation D 1  and D 2 . 
     The linear bearings  41 ,  42  each have a bearing element  46 , which is mounted for linear movement on a bearing receptacle  47 , in the linear bearing  41  along an adjusting axis L 1 , in the linear bearing  42  along an adjusting axis L 2 . 
     The bearing receptacles  47  comprise rotatable bearing blocks or rollers  48 , between which the rod-shaped or bar-shaped bearing elements  46  are accommodated. Naturally, a guide groove, a sliding support or similar linear bearing contour could also be provided as a bearing receptacle  47 . The drawing here is to be understood as an example. 
     The bearing element  46  of the linear bearing  42  is rotatably coupled to a bearing element  46  of the linear bearing  45  using the rotary bearing  44 . The rotary bearing  44  is provided at the respective longitudinal end areas or free end areas of the bearing elements  46  of the linear bearings  42 ,  45  and swivellably couples the bearing elements  46 . 
     The linear bearing  45  supports its bearing element  46  for sliding motion along an adjusting axis L 3 . The bearing axis L 3  is essentially parallel to the working direction AR, but can change its orientation or angle relative to the working direction AR, which is made clearer below. 
     A relative position of the tool holder  24  relative to the guide element  30  can be adjusted by means of the bearing arrangement  40  both about an adjusting swivel axis S and transversely thereto, namely with a movement component K 1 , which runs substantially parallel to the axis of rotation D of the tool holder  24  and/or transversely to the working direction AR, and advantageously with a movement direction component K 2 , which is aligned along the working direction AR and/or at right angles to the axis of rotation D of the tool holder  24 . The adjusting swivel axis S passes through the guide surface  31  at an angle, in particular orthogonally. 
     Essentially, the bearing arrangement  40  is configured in such a way that a control device  60  can control a servo motor arrangement  50  with servo motors  51 ,  52  in such a way that the tool holder  24  and thus the working tool  25  retain their orientation relative to the working direction AR and/or relative to a target working line AL along which working tool  25  is to come into engagement with the workpiece W, for example to make a saw cut. 
     The servo motors  51 ,  52  are assigned to linear bearings  41 ,  42 . For example, the servo motors  51 ,  52  drive the bearing elements  46  of the linear bearings  41 ,  42 . It is possible that the bearing elements  46 , for example, are formed by the output drives of the servo motors  51 ,  52 . It is therefore possible that the linear bearings  41 ,  42  are components of the servo motors  51 ,  52 . 
     If the control device  60  controls the servo motors  51 ,  52  for a simultaneous and equally fast advance of the bearing elements  46  of the linear bearings  41 ,  42 , an angle of the tool holder  24  relative to the adjusting swivel axis S is maintained. This will, for example, displace the working tool  25  in parallel between an adjusting position SP 1  shown in solid lines in  FIG. 6  and an adjusting position SP 2  shown in dashed lines in  FIG. 6 . Naturally, such parallel adjustment is not only possible if the longitudinal side  35  of the guide element  30  runs parallel to the working line AL, but also swivel positions of the guide element  30  relative to the axis of rotation D and/or the flat side  26  of the working tool  25  as shown in  FIGS. 7 and 8 . 
     However, the servo motor arrangement  50  can also be controlled by the control device  60  in such a way that the axis of rotation D changes its swivel position relative to the adjusting swivel axis S, in particular in order to maintain the alignment of the working tool  25  and/or the tool holder  24  relative to the target working line AL, as shown in  FIGS. 7 and 8 . This changes, for example, the angle of the adjusting axes L 1 , L 2  relative to the adjusting swivel axis S, which penetrates the guide plane or guide surface  31  at right angles. At this point it should be noted that the adjusting swivel axis S is not stationary relative to the guide element  30 , but is adjusted within the guide surface  31 , for example with the movement component K 1 , if servo motors  51 ,  52  displace or adjust the working tool  25  or the tool holder  24  in parallel between the two positions shown in the example. 
     In  FIGS. 7 and 8 , the adjusting axes L 1 , L 2  are adjusted anti-clockwise ( FIG. 7 ) and clockwise ( FIG. 8 ) about the adjusting swivel axis S. The adjusting axis L 3  of the linear bearing  46  retains its parallel position relative to the flat side  26  or its perpendicular position relative to the axis of rotation D of the tool holder  24 . 
     These measures are essential in particular because an operator is, so to speak, advancing the hand-held power tool  20  relative to the workpiece W, i.e. advancing or retracting it along the target working line, wherein they may not be able to maintain the angle of the guide element  30  relative to the target working line AL if they adjust the guide element  30  in the working direction AR or at least with a directional component relative to the working direction AR relative to the workpiece W, for example by advancing or retracting it. For this purpose, the operator can, for example, grasp the hand-held power tool by means of an operating handle  39 , in particular a handle. The operating handle  39  is preferably located on the guide element  30 , in particular on its rear area in the working direction AR, for example at or near the transverse side  33 . 
     Due to inaccuracies in handling, when advancing or adjusting the hand-held power tool  20  with a directional component parallel to the target working line AL, the operator therefore not only ideally adjusts the relative position of the guide element  30  exactly along the target working line AL, but also unintentionally at angles to it, as shown in  FIGS. 7 and 8 . Nevertheless, the control device  60  keeps the working tool  25  on course, so to speak, i.e. it does not leave its orientation relative to the target working line AL, but can be adjusted by the operator along the working direction AR with a movement direction component at most. 
     An alternative bearing concept is implemented for the bearing arrangement  140  as shown in  FIGS. 9 to 11 . Identical or similar components known from the bearing arrangement  40  are provided with the same or similar reference numbers in the bearing arrangement  140 . 
     The bearing arrangement  140  comprises a linear bearing  141  at the front in the working direction AR and a linear bearing  141 ,  142  at the rear in the working direction AR, the adjusting axes L 1  and L 2  of which extend transversely, preferably in at least one position approximately at right angles to the working direction AR. 
     The linear bearing  141  corresponds to the linear bearing  41  and is swivellably coupled with a rotary bearing  43  with an axis of rotation D 1  to the drive unit  29  and thus to the tool holder  24 . 
     On the other hand, the linear bearing  142  is rotationally coupled via a rotary bearing  144  to the drive unit  29  and thus to the tool holder  24 . The rotary bearing  144  is located at the free end region of the bearing element of the linear bearing  42  and swivellably or rotatably connects it to the drive unit  29 . The rotary bearing  144  has an axis of rotation D 2 . 
     However, a bearing receptacle  47  of the linear bearing  142  is not fixed to the guide element  30 , as is the case with the linear bearing  42 , but can be swivelled by means of a rotary bearing  145 . The rotary bearing  145  supports both the bearing receptacle  47  and the servo motor  52 , which is intended to drive the bearing element  46  of the linear bearing  142 , swivellably about a swivel axis or axis of rotation D 3 , which passes orthogonally through the guide surface or the guide plane  31 . At this point it should be noted that the axes of rotation D 1 , D 2  or swivel axes of the rotary bearings  43 ,  44 ,  144  and  145  also pass orthogonally through the guide surface or the guide plane  31 . 
     The rotary bearings  143 ,  144  have axes of rotation D 1  and D 2  similar to the rotary bearings  42 ,  44 , which penetrate the guide surface  31  vertically or approximately vertically. 
     The bearing arrangement  40  therefore comprises two rotary bearings and three linear bearings. In contrast, the bearing arrangement  140  comprises only two linear bearings, but three rotary bearings. In both cases, parallel adjustment of the tool holder  24  relative to the adjusting swivel axis S is possible. The rotary bearings  43 ,  44  have bearing axes D 1  and D 2  which penetrate the guide plane or the guide surface  31  vertically or approximately vertically. 
     It can be seen in  FIGS. 9, 10 and 11  that, even in the bearing arrangement  140 , the control device  60  is easily able to maintain a swivel position of the tool holder  24  and the working tool  25  relative to the guide element  30  if it adjusts the guide element  30  and the tool holder  24  relative to each other with one or both of the movement direction components K 1  and/or K 2 , in particular if it adjusts the guide element  30  relative to the tool holder  24 . The working tool  25  always remains optimalty aligned relative to the target working line AL, so that it does not tilt, for example in a kerf that has been sawn into the workpiece W. 
     A further bearing concept is shown in  FIG. 12 , namely using a bearing arrangement  240 . Three rotary bearings  243 ,  244  and  245  are provided for the bearing arrangement  240 . The rotary bearings  243 ,  244  are arranged in front of and behind the drive unit  29  and/or the tool holder  24  relative to the working direction AR. 
     The drive unit  29  is eccentrically connected to the rotary bearings  243 ,  244 , namely by means of the connecting links  246 , the attachment points D 12  and D 22  of which relative to the rotary bearings  243 ,  244  have eccentricities E 1  and E 2  relative to the axes of rotation D 11  and D 21  of the rotary bearings  243 ,  244 . 
     The connecting member  246  between one of the rotary bearings  243  or  244 , in the embodiment of the rotary bearing  243  or the rotary bearing at the front in the working direction, is firmly connected to the drive unit  29  or the tool holder  24 , so that the latter swivels with eccentricity E 1  about the axis of rotation D 1 . The other connecting link  246 , on the other hand, is rotatably coupled to drive unit  29  and thus to tool holder  24 , namely by means of a rotary bearing or swivel bearing  245 . The rotary bearing  245  has an axis of rotation D 31 . 
     Rotary bearings  243 ,  244  are driven by a servo motor arrangement  250 . For example, the servo motor arrangement  250  comprises servo drives or servo motors  251 ,  252  configured as rotary motors or rotary drives, with which the rotary bearing elements and thus the connecting elements  246  are rotatably or swivelably driven or can be driven. The servo motors  251 ,  252  are advantageously controlled by the control unit  60 , for example wirelessly or wired, as already explained. 
     The bearing arrangement  240  also makes it possible for control device  60  to swivel working tool  25  about the adjusting swivel axis S by suitable control of the servo motors  251 ,  252 , but also to adjust the working tool  25  relative to the guide element  30  while maintaining a respective swivel position or swivelled position relative to the adjusting swivel axis S with the movement direction components K 1  and preferably also K 2 . The drawing in  FIG. 12  shows that the working tool  25  is swivelled about the adjusting swivel axis S. However, it can be seen that the guide element  30  changes its relative position relative to the axis of rotation D or the tool holder  24  by this adjustment. This serves to keep the working tool  25  aligned with the target working line AL when guide element  30  is swivelled by the operator relative to the target working line AL. 
     The adjustment kinematics provided in the hand-held power tool  20  with the servo motor arrangement  50  and the bearing arrangement  40  as well as the alternative bearing arrangements  140 ,  240  and the alternative servo motor arrangement  250  are suitable for semi-automatic workpiece machining, in particular semi-automatic sawing operation, in which the operator guides hand-held power tool  20  along the workpiece W only in the working direction AR or against the working direction AR, for example to perform a saw cut along the target working line AL. Both for this largely automated sawing operation or largely automated workpiece machining and for the workpiece machining in which the hand-held power tool  20  is operated without the cooperation of the servo motor arrangement  50 ,  250  or the presence thereof, namely by the operator manually guiding the hand-held power tool  20  along the target working line AL, the methods described below, in which the definition of the target working line AL is considerably facilitated, are suitable. 
     For example, workpiece W is located in a working space R, see  FIG. 1 . The workpiece W is to be machined along the target working line AL, for example, a workpiece part W 1  is to be cut off from a workpiece part W 2 . In order to make a straight saw cut, according to the prior art, a guide ruler or a guide rail would be placed on an upper flat side of the workpiece WO, along which the hand-held power tool  20  is to be guided. This is easily possible with the hand-held power tool  20 , for example by means of the guide contours on the guide surface  31 , which are not explained in detail, for engagement in the guide rail, which is also not shown, but this is not absolutely necessary with the principle explained below. 
     To determine the target working line AL, for example, the workpiece markers M 1  and M 2 , which are at a distance from each other and between which the target working line AL, presently a straight line, should extend, are sufficient. For example, the workpiece markers M 1  and M 2  are line markers or dot markers on the upper flat side WO. With its underside, the lower flat side WO, the workpiece rests for example on a base, in particular on a work table, bearing blocks or the like. The working line AL is to be executed starting from a workpiece front side WS to the opposite workpiece front side between the longitudinal workpiece sides WLR and WLL. 
     However, the operator does not need to draw a connecting line between the workpiece markers M 1  and M 2  in order to locate or visually track the straight target working line AL, so to speak, but uses marker detection device  70  explained below. The marker detection device comprises a marker sensor  71 , which is pin-shaped. For example, the operator can manually grasp the marker sensor  71 , which is indicated by a schematic representation of an operator&#39;s hand H in  FIG. 1 . 
     The marker sensor  71  has a mechanical reference  72  in the form of its tip or longitudinal end, which the operator brings sequentially into coincidence with the workpiece marker M 1  and the workpiece marker M 2  by positioning the reference  72  at or on the respective workpiece marker M 1 , M 2 . 
     The marker detection device  70  detects the respective position of the workpiece marker M 1 , M 2 , namely their coordinate data KD 1  and KD 2 , relative to an at least two-dimensional coordinates system KR 2 , which is clamped in the working space R. For example, the coordinates system KR 2  can extend parallel to the workpiece flat side WO. For example, the coordinate data KD 1  and KD 2  each contain a value relating to the coordinate axes kx, ky of the coordinates system KR 2 , optionally a value relating to a coordinate axis kz of a coordinates system KR 3 . The coordinates system KR 3  is a three-dimensional coordinates system. 
     The coordinates systems KR 2  and KR 3 , for example, are stationary relative to the working space AR. However, in another embodiment, the coordinates systems KR 2  and KR 3  can also be stationary relative to the workpiece W. 
     However, a three-dimensional coordinate detection is preferred, i.e. the marker detection device  70  detects the coordinate data KD 1  and KD 2  as three-dimensional coordinate data. 
     For example, the two-dimensional coordinate data system K 2  comprises coordinate axes kx and ky, the three-dimensional coordinates system KR 3  additionally comprises a coordinate axis kz. The coordinates axes kx, ky and kz are preferably perpendicular to each other. For example, the coordinates axes kx and ky extend parallel to the flat side WO of the workpiece W, while the coordinates axis kz is perpendicular to it, creating a normal through the flat side WO, so to speak. 
     The coordinates systems KR 2  and KR 3  can naturally also be oriented differently relative to the working space R. However, in the embodiment shown in the drawing, the explained orientation of the coordinates system KR 2  or KR 3  is advantageous, e.g. the coordinates sensors  80 ,  81  can be placed directly on the flat side WO, so that the coordinates sensors  80 ,  81  have the same position relative to the coordinate axis kz. 
     Naturally, the coordinates sensors  80 ,  81  can also be positioned anywhere else in the working space R, as shown in  FIGS. 14 and 15 . In particular in this case, but also for positioning on the workpiece flat side WO, it is advantageous if at least one of the coordinates sensors  80 ,  81  is configured and/or usable to provide the three-dimensional coordinates system KR 3 . 
     Coordinates sensors  80 ,  81  can, for example, be set down on their undersides, on the flat side WO of the workpiece, on which there are utility surfaces  82 . Thus, a position of a coordinates sensor  84 , which is arranged in a housing  85  of the coordinates sensors  80 ,  81 , is known in advance relative to the utility surface  82  provided on the housing  85 , so that the coordinate axis kz need not be significant in itself, but can certainly be included in the following considerations. 
     The fastening means  83 , e.g. the adhesive fastening means  83 A, e.g. a rubber coating, and/or suction fastening means  86 , e.g. a suction head or the like, may be provided on or in addition to the utility space  82  in order to improve the hold of the respective coordinates sensors  80 ,  81  on the workpiece W if the coordinate data KD 1 , KD 2  are determined as explained below. A coordinate transmitter  84  of the coordinates sensor  80 ,  81  sends reference information RX and RY, for example a pattern of lines that are angled, for example perpendicular to each other. It is possible that the coordinate transmitter  84  transmits the respective line pattern or the reference information RX and RY sequentially or simultaneously. The reference information RX and RY are suitable for a three-dimensional acquisition of the coordinate data KD 1 , KD 2 , i.e. relative to the three-dimensional coordinates system KR 3 . However, it is also possible, for example, that the coordinates sensor  84  only transmits the reference information RX, which enables a two-dimensional orientation relative to the two-dimensional coordinates system KR 2 . For example, the reference information RX includes lines that extend parallel to the coordinate axis kz and are arranged side by side relative to the coordinate axes kx and/or ky. For example, the coordinate transmitter  84  sends the lines of the reference information RX and/or RY sequentially or simultaneously. 
     The coordinates sensors  80 ,  81  are arranged at a distance on the workpiece W. Consequently, it is even possible for the marker detection device  70  to determine its respective position in the coordinates system KR 2  and/or KR 3  by means of triangulation. However, based on the spatially spaced reference information RX and RY, it is sufficient if one of the coordinates sensors  80  or  81  is present. 
     The pieces of reference information RX and RY are, for example, light signals, microwaves or similar other reference information that can be transmitted contactlessly. The light signals can also be in the non-visible range, for example the infrared range or the ultraviolet range. In any case, the marker detection device  70  can, so to speak, locate and/or determine its respective position relative to the coordinates system KR 2 , KR 3  by means of the at least one coordinates sensor  80  and/or  81  in order to detect the coordinate data KD 1  and KD 2 . 
     At least one sensor  73 , preferably an arrangement of several sensors  73 , is arranged on the marker detection device  70 . 
     For example, the sensors  73  are located at a longitudinal end area of the marker sensor  71  remote from the reference  72 . 
     The sensors  73  are suitably spaced from one another so that at least one of the sensors  73  can receive the reference information RX and/or RY. The arrangement of sensors  73  at a distance from one another on the marker sensor  71  also enables triangulation or other spatial determination of the coordinates KD 1 , KD 2  even if only one of the coordinates sensors  80 ,  81  is present. 
     The marker detection device  70  expediently has an inclination sensor  79  to determine the local relationship of the reference  71  to the at least one sensor  73  to provide the coordinate data KD 1 , KD 2 . 
     The marker detection device  70  can detect the coordinate data KD 1 , KD 2  as a function of at least one triggering condition. For example, a marker sensor  71  may be a switch  75 , in particular an electric pressure switch, an electric switch, preferably a pressure switch or the like. A capacitive or other manually actuated sensor is also suitable as a switch  75 . When the operator actuates the switch  75 , marker detection device  70  records the position of the respective reference  72  and thus determines the coordinate data KD 1  and/or KD 2 . 
     Alternatively or additionally, a time condition is also suitable as a triggering condition. For example, if the operator holds the reference  72  at the reference  72  for a predetermined period of time, such as  10  seconds or longer, this is interpreted as a triggering condition to detect the coordinate data KD 1  or KD 2  from the marker detection device  70 . The marker detection device  70  has, for example, a motion sensor  77 , to determine a predetermined dwell time of the reference  72  at one of the workpiece markers M 1  or M 2 . 
     It is also possible for the marker detection device to determine the coincidence or spatial arrangement of the reference  72  at the workpiece marker M 1  or M 2  on the basis of a distance measurement, for example using a distance sensor  76 , for example an optical sensor. For example, in comparison to the workpiece surface on the flat side WO, the workpiece marker M 1  or M 2  is a contrasting workpiece marker that can be detected optically. 
     If the marker detection device  70  has acquired the coordinate data KD 1  and KD 2 , it can transmit them to the hand-held power tool  20  by means of a transmitter  74 , for example. One embodiment of the invention may provide that a holding fixture  38 , for example a plug-in fixture, is provided on the hand-held power tool  20  for holding the marker detection device  70 . For example, it can be inserted into the holding fixture  38 . 
     The marker detection device  70  transmits the coordinate data KD 1  and KD 2  by means of its transmitter  74  wirelessly or via a wired network to an interface of the hand-held power tool  20 , for example a Bluetooth interface, a USB interface, an  120  interface or the like. The interface  64  and the coordinates sensor  84  have for example USB bus interfaces, I2C bus interfaces, WLAN interfaces, Bluetooth interfaces or the like. The interface  64 , for example, can be located in the holding fixture  38 . However, the holding fixture  38  is not necessary, i.e. the marker detection device  70  does not necessarily have to be attached to the hand-held power tool  20  in order to transmit the coordinate data KD 1 , KD 2 . 
     The control device  60  has a processor  61  and a storage device  62 . A control program  63  is stored in the storage device  62 , for example, which contains program code executable by the processor  61 . The control program  63  forms a guide means  65  for guiding the hand-held power tool  20  according to the coordinate data KD 1  and KD 2  in a working area, present along the target working line AL. 
     For example, the guide means  65  read the coordinate data KD 1 , KD 2 , each of which contains partial coordinates relative to the coordinate axes kx, ky and kz. Using methods known per se from the descriptive geometry, the guide means  65  can determine the working area data AD representing the working line AL from the coordinate data KD 1  and KD 2 , preferably storing them in the storage device  62 . For example, to determine the working area data AD, the guide means  65  forms a vector difference between the coordinate data KD 1  and KD 2 . 
     The guide means  65  then guides the hand-held power tool  20  along the working line AL, wherein the servo motor arrangement  50  is controlled so that the working tool  25  moves along the working line AL. In this connection, it is also advantageous if the hand-held power tool  20 , in particular the guide means  65 , is oriented to the coordinates system KR 2  or KR 3 , for which the coordinates sensors  80  and/or  82  are advantageous. For example, on the hand-held power tool  20  sensors  66 , in particular a plurality or at least two sensors  66  are provided for the receipt of reference information RX and/or RY. In this way, the hand-held power tool can always determine its position in the working space R, especially relative to the target working line AL. 
     The sensors  66  are components of an orientation means  67  of the hand-held power tool  20  for orientation in the working space R and/or relative to coordinates system KR 2  and/or KR 3 . 
     In the form of sensors  67 , the marker detection device  70  has orientation means  78  with which it can orient itself relative to the coordinates system KR 2 , KR 3 . 
     The guide means  65  determines the working area data AD for the target working line AL, for example a starting point for the straight line representing the working line AL and the further course relative to the coordinate axes kx and ky, optionally kz. 
     Naturally, instead of the linear working area, a two-dimensional or flat working area, for example for milling the workpiece W, can also be determined in the aforementioned way. For example, a further workpiece marker M 3  could be detected by the marker detection device  70 . The workpiece markers Ml, M 2  and M 3  are provided, for example, at the corners of a triangle whose surface is to be ground or milled by a hand-held power tool according to the invention. The marker detection device  70  determines in the manner described above, for example, coordinate data KD 1 , KD 2 , KD 3  of the workpiece markers in M 1 , M 2  and M 3  and transmits these or working area data AD 2  already defining the working area AB, which is located in the area defined by the workpiece markers M 1 , M 2  and M 3 , to the hand-held power tool  20 . It is also possible that the control device  60  itself determines the working area data AD 2  defining the working area AB, for example by using the control program  63 . 
     Finally, the working area data AD does not necessarily have to represent a straight line. In particular, if a hand-held power tool according to the invention is designed as a jigsaw, a course with bends and curves is also possible. For example, it may be necessary to saw a target working line AL 2  in the workpiece W, which extends from the workpiece marker M 1  via the workpiece marker M 4  to the workpiece marker M 2 . The marker sensor  71  must be positioned on the workpiece markers M 1 , M 4  and M 2  so that its reference  72  records the respective coordinate data of the workpiece markers M 1 , M 4  and M 2 . The guide means  65  and/or marker detection device  70  can then, for example, provide an arc-shaped line or a triangular line defined by the workpiece markers M 1 , M 4  and M 2  as a target working line AL 2  for guiding the hand-held power tool  20 . 
     The operator is assisted in guiding the hand-held power tool  70  preferably by an optical display, in particular a display device  55 , of the hand-held power tool. This is indicated schematically in  FIG. 5 . The display device  55 , for example, is located on the side of the hand-held power tool  20  facing away from the guide surface  31 , in particular the top side, so that it can be easily seen by the operator. The display device  55  preferably indicates on the display device  55  an adjustment range SB adjustable by the servo motor arrangement  50 , so to speak a corridor or window, within which the working tool  25  can be adjusted by the servo motor arrangement  50  relative to the target working line AL to be held. 
     The operator is also provided with additional useful information on the display device  55 , for example an actual indicator IP indicating an actual position of the working tool  25  and/or a deviation indicator IA indicating a deviation of the guide element  30  from an ideal line, the target working line AL. The indicators IA and IP are expediently linear. 
     For example, it can be seen in  FIG. 5  that the indicators IA and IP are parallel but offset in the left position of the hand-held power tool  20  relative to the workpiece W, and the markers or indicators IA and IP have different angular and transverse distances from each other in the middle and right illustrations of the hand-held power tool  20 . This tells the operator how to optimally advance the hand-held power tool  20  relative to the target working line AL or which angle to set in order to make work easier for the servo motor arrangement  50 , so to speak. 
     Instead of or in addition to the display device  55 , which represents an output device  56  or a component of an output device  56 , there may also be provided, for example, indicator lights  57 A,  57 B, which indicate to the operator by means of coloured light, for example red and green, and/or optical symbols (arrows or the like) whether the hand-held power tool  20  is optimally guided in the area of the target working line AL or along the target working line AL. 
     Furthermore, an acoustic signal may also be useful. For example, the output device  56  has a speaker  58  which gives an acoustic signal to the operator, for example by means of a warning tone, when they guide the guide element  30  in such a way that the adjustment area adjustable by the servo motor arrangement  50  is exceeded. 
     The above-mentioned visual indicators IA and IP and/or the indicator lights  57 A,  57 B can also be used without servo motor arrangements  50 ,  150  when the hand-held power tool  20  is manually guided along the target working line AL. These indication means can be used to indicate to the operator how to operate the hand-held power tool  20  in order to maintain the target working line AL. 
     A further sensory concept for the detection of workpiece markers M 1 , M 2  is illustrated using a system  110  as shown in  FIG. 4 . A marker detection device  170 , like the marker detection device  70 , is a separate component from the hand-held power tool  20 , without a drive and therefore mobile and easy to handle. A marker sensor  171  of the marker detection device  70  has, for example, a housing  176  which, for example, could be applied as a mechanical reference directly to one or both of the workpiece markers M 1  or M 2 , for example with its longitudinal side or the like. However, an optical concept has been implemented in which an optical reference  172 , namely a light beam, is output by a light source  173 . The light source  173  includes, for example, a laser beam or the like which the operator directs at the workpiece markers M 1  and M 2 . 
     The marker detection device  171  also has a camera  175  and a transmitter  174  for coordinate data KD 1  and KD 2 , which can be determined using the camera  175 . For example, the camera  175  records the workpiece markers M 1 , M 2  relative to a so to speak optical or mechanical coordinates sensor  180 . 
     For example, the coordinates sensor  180  comprises a surface  181 , in particular a strip, which can be placed along the working line AL or next to the working line AL by an operator on the workpiece W. The surface  181  is provided with identifiers  182  in a unique pattern to which marker detection device  170  can orient itself. The identifiers  182  include, for example, a cube pattern with uneven distribution or the like. The coordinates sensor  180 , for example, can be fastened to the workpiece 
     W using the fastening means  183 , in particular hooks, which can be attached to the workpiece end faces WS. Naturally, the surface  181  can also be formed by a film or a wall or the like, which can adhere to the flat side WO due to negative pressure or the like of other adhesion. Using the camera  174 , the marker detection device  170  accordingly detects the workpiece markers M 1  and M 2  relative to the coordinates sensor  180  and displays this on a display device  175 . For example, the marker detection device  70  can determine coordinate data KD 1  and KD 2  on the basis of a distance between, on the one hand, the workpiece marker M 1 , M 2  and, on the other hand, the coordinates sensor  180  and transmit them to the interface  64  of the hand-held power tool  20  using its coordinates sensor  174 . 
     The hand-held power tool  20  has orientation means  167 , for example a camera  166 , for orientation on the coordinates sensor  180 . The control device  60 , for example, controls the servo motor arrangement  50  to maintain the target working line AL, wherein it evaluates data from the camera  166  or the orientation means  167 . 
     It is also possible that only one workpiece marker is detected, for example the workpiece marker M 1 , which then defines the starting point for the working area to be machined. If, in this case, the orientation of the workpiece marker M 1  is also known, for example a directional component relative to the target working line AL, this information is sufficient for the marker detection device  70  and/or control device  60  to determine the target working line AL. 
     Furthermore, default data VO, in particular CAD data, can be stored and/or created on a computer  11 , e.g. by a CAD program which defines the working area, e.g. the course and/or length of the working line AL, the geometry of the working area AB or the like. To position or locate this working area, for example a working line or a surface to be machined, on the workpiece W, so to speak, the operator can use the marker detection device  70  to index the workpiece marker M 1 , for example, and transmit its coordinate data KD 1  to the hand-held power tool  20 . This has a receiving interface  69  for receiving default data VO. Using default data VO and coordinate data KD 1  of the workpiece marker M 1 , for example, the target working line AL or AL 2  or also the flat area AB can be defined. For example, the control program  63  determines the working area data AD on the basis of default data VO and coordinate data KD 1 . 
     In the previous embodiments, it was assumed that the workpiece W remains in place relative to the two-dimensional or three-dimensional coordinates system KR 2  or KR 3  after the detection of at least one workpiece marker M 1 , M 2 . However, it is also possible that the workpiece W is moved between the detection of the workpiece marker(s) and the workpiece machining, which is explained in more detail in the embodiment shown in  FIGS. 14 and 15 . 
     For example, it is possible that the marker detection device  70  first detects two workpiece markers M 1  and M 2  and then the workpiece W is brought into a different position relative to the coordinates sensors  80 ,  81 , which are preferably arranged freely in the working space R, but in any case are not placed on the workpiece W to be machined, as in the previous embodiments. Thus, the workpiece markers M 1  and M 2  are, so to speak, related to a two-dimensional or three-dimensional coordinates system that is completely independent of the workpiece W. 
     Now it is possible, for example by means of a camera  90 , which is also freely arranged in the working space R, to follow workpiece movements of the workpiece W after the detection of the workpiece markers M 1  and M 2 , so to speak. For example, the camera  90  transmits coordinate data of the workpiece W to the hand-held power tool  20 . This data indicates the position of the workpiece W when the workpiece markers M 1  and M 2  are detected. 
     For example, by means of a wireless or wired transmitter  91 , the camera  90  sends to the interface  64  coordinate data of the workpiece W, namely workpiece position data WP 1 , while capturing the workpiece markers M 1  and M 2  as shown in  FIG. 14 . 
     If the workpiece W is then moved, for example swivelled about an axis parallel to the working line AL, so that the flat side WU comes up, so to speak ( FIG. 15 ) and the workpiece W takes up a machining position BP, the camera  90  in turn captures the coordinate data of the workpiece W, namely the workpiece position data WP 2 , which the camera  90  in turn sends to the interface  64  of the hand-held power tool  20 . 
     The control program  63  can determine the working area data AD using coordinate data KD 1  and KD 2  of the workpiece markers M 1  and M 2  and the workpiece position data WP 1  WP 2 , which the camera  90  determines using the position of the workpiece W 1  when the workpiece markers M 1  and M 2  are detected and immediately before machining by the hand-held power tool, according to  FIG. 15 . For example, the control program  3  forms a difference between the workpiece position data WP 2  and WP 1  and transforms the coordinate data KD 1 , KD 2  with the corresponding tracking data VD obtained from the difference. 
     Naturally, in addition to the workpiece position data WP 1  and WP 2 , the camera  90  can also determine further workpiece position data that is entered into the tracking data VD, for example during the movement of the workpiece W to the machining position BP. 
     The camera  90  is preferably a stereo camera, which has two combinations of lens and sensor  92 ,  93  in order to record stereoscopically and thus spatially the position of the workpiece W in the working space R. Preferably, the camera  90  also has a projector  94 , for example for projecting a stripe pattern or other identification structure or a relief pattern. Thus the camera can, for example, determine a three-dimensional image of the workpiece W. 
     At this point it should be added that the hand-held power tool can naturally also be guided interactively with the camera  90 , i.e. that, for example, the guide means  65  receive from the camera  90  a respective relative position of the hand-held power tool relative to the coordinates system KR 2  or KR 3  in order to guide the working tool  25  according to the target working line AL. 
     The camera  90  forms a coordinate detection device  95 , which can, for example, record the coordinates of the workpiece W and/or the hand-held power tool  20  relative to the coordinates system KR 2  or KR 3 . 
     Coordinate detection or position detection can be facilitated by the fact that, for example, one or a plurality of device reference markers  68  are arranged on the hand-held power tool  20  and/or one or more workpiece position reference markers  98  are arranged on the workpiece W. 
     The device reference markers  68  are preferably arranged at relatively large distances on the hand-held power tool  20 , for example on opposite extremities of the machine housing  29 . The device reference markers  68  include, for example, reflective markers, contrast markers or the like which are detectable by the camera  90 . 
     For example, the coordinates sensor  180  is suitable as a workpiece position reference marker. Three-dimensional markers may also be provided as workpiece position reference markers, for example base bodies or housings of workpiece position detection devices  97  explained below. The camera  90  can record their position, so to speak, in the position shown in  FIG. 14  and in the processing position BP according to  FIG. 15 . 
     The workpiece position detection devices  97 A,  97 B can, for example, be detachably attached to the workpiece W by means of fastening means  197 , for example adhesive means, in particular adhesive elements, suction heads or the like. For example, the workpiece position detection device  97 A is located on the flat side WO, and the workpiece position detection device  97 B on the flat side WU. 
     A concept in which the workpiece position detection devices  97 A,  97 B so to speak actively detect their respective position and thus the position of the workpiece W in the working space R is expedient. The workpiece position detection devices  97 B,  97 B have, for example, sensors  99  to receive reference information RX and/or RY of the coordinates sensors  80 ,  81 . The workpiece position detection devices  97 B,  97 B can thus transmit workpiece position data WP 1 , WP 2  corresponding to the respective position of the workpiece W during the detection of workpiece markers M 1 , M 2  ( FIG. 14 ) and the machining position BP provided for machining by the hand-held power tool  20  ( FIG. 15 ) to the control device  60 , for example wirelessly or via a wired network via the interface  64 , for which purpose they have, for example, wired and/or wirelessly transmitting transmitters  100 . 
     Using the workpiece position data WP 1 , WP 2 , the control device  60  can, for example, determine tracking data VD in order to determine the target working line AL, which is now located on the upturned flat side WU, using this tracking data VD and coordinate data KD 1 , KD 2  of the workpiece markers M 1 , M 2 . 
     In the system  310  shown in  FIG. 17 , the hand-held power tool  20  has one or more cameras  366 ,  367 . The at least one camera  366 ,  367  can, for example, first detect a workpiece marker in a detection position or measuring position PM. The workpiece marker is defined, for example, by an optical workpiece marker of the type of the workpiece marker M 1 , for example a pencil mark and/or an imaginary line, or a desired distance between, on the one hand, the longitudinal side  35  of the guide element  30 , which in this case provides or forms a mechanical reference  35 A, and the longitudinal side of the workpiece WLR. While the workpiece marker is being detected, the drive motor  22  is switched off, which is why the hand-held power tool  20  is optimally stationary relative to the workpiece W for detecting its current position and thus the reference  35 A. Furthermore, the handling is simple. 
     For example, the at least one camera  366  is located near the guide element  30 . On the other hand, the camera  367  is positioned at a distance from the guide element  30 , for example on the machine housing  21 . For example, the at least one camera  366 ,  367  detects a position of the hand-held power tool  20  in the working space R on the basis of a detection of a space contour KR of the working space R. For this purpose, the operator can, for example, tap the switch  23  without switching on the drive motor  22 . However, a special switch  375 , such as the switch  75  of the marker detection device  70 , may also be provided to detect the reference position or the position of at least one workpiece marker M 1 . 
     The space contour KR, for example, includes surfaces F 1 , F 2  and F 3  that are at an angle to each other. Between the surfaces F 1 , F 2  there is a space-inside corner E 1 , between the surfaces F 2  and F 3  a space-outside corner E 2 . In this way, the hand-held power tool  20  can orient itself, so to speak, in the working space AR on the basis of the space contour KR in order, for example, to first determine the workpiece marker M 1  in a detection position PM and then, after switching on the drive motor  22 , to guide the working tool  25  relative to the target working line AL using the guide means  65 . 
     Instead of one or more of the cameras  366 ,  367  and/or the camera  90 , a lidar, radar or the like can of course also be provided, which is suitable for recording the space contour KR or for determining the position of, for example, the hand-held power tool  20 . 
     Some transformation processes of coordinates and coordinates systems will be explained using the embodiment shown in  FIG. 18 . For example, the coordinates system KR 3  is fixed with regard to the working space R and is, so to speak, specified by the coordinates sensors  80  and/or  81 . The coordinates sensors  80 ,  81  can be freely arranged in the working space R, i.e. away from the workpiece W. 
     For example, the marker detection device  70  has a local three-dimensional coordinates system KM 3 , whose coordinate axes mx, my and mz are at an angle to each other. The point of reference  72  is distant from this coordinates system KM 3 , for example relative to the axis mz, by a distance value, for example  5  cm. As a quaternion, for example, the location of the reference  72 , in the drawing example at the same time as the workpiece marker M 2 , where the reference  72  is located according to  FIG. 18 , is described as 
       Q[72]=(0,0,0 −5)
 
     When using quaternions relative to the marker detection device  70 , for example, it is possible, on the one hand, to detect the quaternion of the reference  72  or the workpiece marker M 2  and, on the other hand, the quaternion of the coordinates system KM 3 , which are multiplied together to obtain an intermediate quaternion. 
     The coordinates of the workpiece marker M 2  are now obtained by multiplying the intermediate quaternion by the intermediate quaternion-1 (the inverted quaternion). 
     The sensors  73  of the marker sensor  71  or the marker detection device  70  determine the position of the local coordinates system KM 3 , which is related to the marker detection device  70 , relative to the global coordinates system KR 3 , which is stationary relative to the working space R, in particular by means of a translational displacement of the coordinates system KM 3  relative to the coordinates system KR 3 . In addition, the sensors  73  or their evaluation device, which is not shown individually in the drawing, can determine the rotation of the coordinates system KM 3  relative to the coordinates system KR 3 , for example using formulae (1), (2) and (3) mentioned above. In this way the location or point of reference  72 , i.e. the workpiece marker M 2 , can be converted to the coordinates system KR 3 . This can be achieved, as explained, by the marker detection device  70 , but also, for example, by the control device  60  of the hand-held power tool  20  if it receives coordinate data of the workpiece marker M 2  or the location of the reference  72  and at least one piece of information about the orientation of the local coordinates system KM 3  of the marker detection device  70 . 
     The guide means  65  or the control device  60  can also operate with a local coordinates system related to the hand-held power tool  20 , for example a coordinates system KW 3  related to the hand-held power tool  20 , which has coordinate axes wx, wy and wz which are perpendicular to each other. These can also be converted to the global coordinates system KR 3 , which is related to the working space R, using the rotation matrices (1), (2) and (3) mentioned above, for example, using the program code that the control program  63  contains and that the processor  61  can execute. For example, the guide means  65  or control device  60  can relate the coordinates of a penetration area EB, for example a front cutting edge into the workpiece W, of the working tool  25  to the local coordinates system KW 3  in order to position and/or guide the working tool  25  optimally relative to the working area AB, in particular the working line AL. 
     In the same way, the position of the workpiece W in the working space R can also be tracked, for example using the workpiece position detection device  97 , which also has its local coordinates system KT 3  with coordinate axes tx, ty and tz, which is mobile, so to speak, relative to the working space R. The location of the reference  72  or the workpiece marker M 2  is known in the situation shown in  FIG. 18  relative to the local coordinates system KM 3  of the marker detection device  70  and relative to the coordinates system KT 3  of the workpiece position detection device  97 . If the position of the workpiece marker M 2  on the coordinates system KT 3  is now known and the workpiece W is then moved, the new position of the coordinates system KT 3  can be determined after the repositioning of the workpiece W, for example its rotation and/or translational displacement, to which the location or the coordinates of the workpiece marker M 2  are related. This allows the new coordinates of the workpiece marker M 2  to be determined relative to the global coordinates system KM 3 , which refers to the working space R. A rotation of the workpiece W about an axis, for example about its longitudinal axis or about a longitudinal central axis, can be tracked in particular by means of the formulae (1)-(3) mentioned at the beginning relative to the coordinates system KR 3 . 
     
       
         
           
               
               
               
               
             
               
                   
               
             
            
               
                 10 
                 System 
                 60 
                 Control device 
               
               
                 11 
                 Computer 
                 61 
                 Processor 
               
               
                 12 
                   
                 62 
                 Storage device 
               
               
                 13 
                   
                 63 
                 Control program 
               
               
                 20 
                 Hand-held power tool 
                 64 
                 Interface for 70 
               
               
                 21 
                 Machine housing 
                 65 
                 Guide means 
               
               
                 22 
                 Drive motor 
                 66 
                 Sensors 
               
               
                   22A 
                 Gear 
                 67 
                 Orientation means 
               
               
                 23 
                 Switch 
                 68 
                 Device reference marker 
               
               
                 24 
                 Tool holder Axis of rota- 
                 69 
                 Receiving interface 
               
               
                   
                 tion D 
               
               
                 25 
                 Working tool 25A Cutting 
                 70 
                 Marker detection device 
               
               
                   
                 tool 
               
               
                 26 
                 Flat side 
                 71 
                 Marker sensor 
               
               
                 27 
                 Front edge of 25 
                 72 
                 Reference 
               
               
                 28 
                 Energy storage device 
                 73 
                 Sensors 
               
               
                   28A 
                 Power supply cable 
                 74 
                 Coordinate data transmitter 
               
               
                   28B 
                 Power plug 
                 75 
                 Switch 
               
               
                 29 
                 Drive unit 
                 76 
                 Distance sensor 
               
               
                 30 
                 Guide element 
                 77 
                 Motion sensor 
               
               
                 31 
                 Guide surface 
                 78 
                 Orientation means 
               
               
                 32 
                 Front transverse side 
                 79 
                 Tilt sensor 
               
               
                 33 
                 Rear transverse side 
                 80 
                 Coordinates sensor 
               
               
                 34 
                 Left longitudinal side 
                 81 
                 Coordinates sensor 
               
               
                 35 
                 Right longitudinal side 
                 82 
                 Utility surface 
               
               
                 36 
                 Depth adjustment bearing 
                 83 
                 Adhesive fastening means 
               
               
                   
                 Depth adjusting axis T 
               
               
                 37 
                 Mitre bearing Mitre axis G 
                 84 
                 Coordinate transmitter 
               
               
                 38 
                 Holding fixture 
                 85 
                 Housing 
               
               
                 39 
                 Operating handle 
                 86 
                 Suction fastening means 
               
               
                 40 
                 Bearing arrangement 
                 87 
               
               
                 41 
                 Linear bearing 
                 88 
               
               
                 42 
                 Linear bearing 
                 89 
               
               
                 43 
                 Rotary bearing 243 
                 90 
                 Camera 
               
               
                 44 
                 Rotary bearing 244 
                 91 
                 Transmitter 
               
               
                 45 
                 Linear bearing 145 Rotary 
                 92 
                 Lens/Sensor 
               
               
                   
                 bearing 245 
               
               
                 46 
                 Bearing member of 41, 42 
                 93 
                 Lens/Sensor 
               
               
                 47 
                 Bearing receptacle 41, 42 
                 94 
                 Projector 
               
               
                   
                   
                 95 
                 Coordinate detection device 
               
               
                   
                   
                 96 
                 Tracking means 
               
               
                   
                   
                 97 
                 Workpiece position detection 
               
               
                   
                   
                   
                 device 
               
               
                 48 
                 Rollers of 47 
                 98 
                 Workpiece position reference 
               
               
                   
                   
                   
                 marker 
               
               
                 49 
                   
                 99 
                 Sensors 
               
               
                 50 
                 Servo motor arrangement 
                 100 
                 Transmitter 
               
               
                 51 
                 Servo motor 
                 197 
                 Fastening means 
               
               
                 52 
                 Servo motor 
               
               
                 53 
               
               
                 54 
               
               
                 55 
                 Display device 
               
               
                 56 
                 Output device 
               
               
                 57 
                 Indicator lights 
               
               
                 58 
                 Speaker 
               
               
                 59 
               
               
                 W 
                 Workpiece 
                 R 
                 Working space 
               
               
                 WO 
                 Upper flat side WU Lower 
                 IN 
                 Indicator 
               
               
                   
                 flat side 
               
               
                 WS 
                 Workpiece front side 
                 IP 
                 Actual position 
               
               
                 WL 
                 R/L Workpiece longitudinal 
                 AB 
                 Adjustment area 
               
               
                   
                 side 
               
               
                   
                   
                 AB 
                 Working area 
               
               
                   
                   
                 AD 
                 Working area data 
               
               
                 VO 
                 Default data 
                 KDx 
                 Coordinate data 
               
               
                 WP1 
                 Workpiece position data 
                 RX 
                 RY Reference information 
               
               
                 WP2 
                 Workpiece position data 
                 kx 
                 ky kz Coordinates axes 
               
               
                 VD 
                 Tracking data 
                 KR2 
                 KR3 Coordinates system fixed 
               
               
                 SP1 
                 SP2 Adjusting positions 
                 Mx 
                 Workpiece marker 
               
               
                 IA 
                 Deviation indicator 
                 L1 L2 L3 
                 Adjusting axes of 41, 42, 45 
               
               
                 IP 
                 Actual indicator 
                 S 
                 Adjusting swivel axis 
               
               
                 AB 
                 Adjustment area 
                 K1 
                 Movement component Trans- 
               
               
                   
                   
                   
                 verse to AR 
               
               
                 EB 
                 Penetration area 
                 K2 
                 Movement component along AR 
               
               
                   
                   
                 AL 
                 Target working line 
               
               
                   
                   
                 AR 
                 Working direction 
               
               
                 166  
                 Camera 
                 KR 
                 Space contour 
               
               
                 167  
                 Orientation means 
                 180 
                 Coordinates sensor 
               
               
                   
                   
                 181 
                 Surface 
               
               
                 170  
                 Marker detection device 
                 182 
                 Identifier 
               
               
                 171  
                 Marker sensor 
                 183 
                 Fastening means 
               
               
                 172  
                 Optical reference 
               
               
                 173  
                 Light source 
               
               
                 174  
                 Transmitter 
                 240 
                 Bearing arrangement 
               
               
                 175  
                 Camera 
                 241 
               
               
                 176  
                 Housing 
                 242 
               
               
                   
                   
                 243 
                 Rotary bearing 
               
               
                   
                   
                 244 
                 Rotary bearing 
               
               
                   
                   
                 245 
                 Rotary bearing 
               
               
                   
                   
                 246 
                 Connecting member 
               
               
                   
                   
                 250 
                 Servo motor arrangement 
               
               
                   
                   
                 251 
                 Servo motor rotary drive 
               
               
                   
                   
                 252 
                 Servo motor rotary drive