METHOD FOR OPERATING A PERMANENTLY EXCEEDED SYNCHRONOUS MOTOR OF A HAND-POWERED MACHINING DEVICE AND HAND-POWERED MACHINING DEVICE

Description

SCOPE OF APPLICATION AND STATE OF THE ART

[0001] The invention relates to a method for operating a permanent magnet synchronous motor of a hand-held processing device and a hand-held processing device.

[0002] DE 10 2014 226 285 A1 discloses an embodiment of an operating circuit for operating a motor, wherein the operating circuit includes a rotation state generation circuit connected to a state controller. The state controller is connected to a pulse width modulation detection circuit, a timer, and an operating time control. According to a further embodiment, a method for operating the motor includes coupling a single Hall sensor to the motor and using the single Hall sensor to determine the position of a rotor of the motor. The operating circuit pulls the rotor such that one of its north or south poles is adjacent to the single Hall sensor. Once the rotor pole is adjacent to the sensor, the motor starts.

[0003] US patent 2020 / 0343838 A1 discloses a power tool comprising a brushless motor with a stator defining multiple phases and a rotor. It includes a power unit with circuit breakers for supplying power to the motor. A primary controller is connected to the power unit to output drive signals that drive the motor phases across a series of rotor rotation sectors. The primary controller measures the motor's back EMF voltage and performs a motor commutation transition from the current sector to the next sector based on this back EMF voltage.A secondary controller is provided to receive at least one of the drive signals, to calculate a speed and / or direction of rotation of the motor from the drive signals, and to take corrective action to interrupt the power supply to the motor if it detects an overspeed condition or an incorrect direction of rotation.

[0004] US Patent 5,432,414 A discloses that when a sensorless spindle motor with a rotor and multiple coils is started, a CPU outputs phase control signals to an excitation phaser circuit to force the rotor to rotate. The CPU uses rotor position signals from a rotor position sensing circuit to determine whether the rotor is rotating in the forced rotation. If the rotor is not rotating, the CPU attempts to force rotation again. With each subsequent attempt at forced rotation, the CPU decreases the rotational speed of an excitation phase for each coil. The CPU can also perform the forced rotation after the rotor has been aligned to any desired position. If the rotor is not rotating in the forced rotation, the CPU attempts to force rotation again. With each subsequent attempt at forced rotation, the CPU changes the excitation start phase. TASK AND SOLUTION

[0005] The invention aims to provide a method for operating a permanent magnet synchronous motor of a hand-held processing device and a hand-held processing device, each of which has improved properties.

[0006] The invention solves this problem by providing a method and a handheld processing device as described in the independent claims. Advantageous further developments and / or embodiments of the invention are described in the dependent claims.

[0007] The method according to the invention is for operating a permanent magnet synchronous motor of a handheld machining device. The method comprises the following steps: a) sensorless determination of a position variable representative of the position of a rotor of the synchronous motor at rest, in particular of the rotor. b) Determination of a direction variable for continuous rotation of the rotor from rest in a direction as a function of the determined position variable, such that the magnitude of an achievable torque that can be generated by the synchronous motor when it is sensorlessly driven to rotate in that direction is greater than the magnitude of a breakaway torque limit of the machining device. c) sensorless control of the synchronous motor as a function of the determined direction variable to rotate in that direction.

[0008] This enables, in particular, sensorless detection and sensorless control, a simple and / or, in particular, cost-effective design of the synchronous motor and / or, in particular, the processing device.

[0009] Additionally or alternatively, this enables, in particular the determination of the direction variable, a particularly reliable starting or starting of the synchronous motor, especially from any possible position of the rotor.

[0010] In particular, the process, operation, detection and / or control can be automatic.

[0011] The term "start" or "start" can be used synonymously with the term "operate".

[0012] The terms "brushless DC motor" (abbreviated BLDC or BL motor, also electronically commutated motor, or EC motor) or "permanent magnet synchronous motor" can be used synonymously with "permanent magnet synchronous motor". Additionally or alternatively, the synchronous motor can be three-phase and / or have a stator, particularly a three-phase one. Furthermore, the synchronous motor may or may not have a magnetic sensor, such as a Hall sensor, especially for detection and control. For further information, please refer to the relevant technical literature.

[0013] The processing device may include a tool, and the synchronous motor may be designed to drive the tool. Additionally or alternatively, the processing device may be electric, in particular a battery-powered device. Furthermore, additionally or alternatively, the processing device may be a gardening, forestry, construction, or soil cultivation tool.

[0014] Hand-held processing equipment can mean that the processing equipment has a mass of a maximum of 50 kg (kilograms), in particular a maximum of 20 kg, in particular a maximum of 10 kg, in particular a maximum of 5 kg, and / or a minimum of 0.2 kg, in particular a minimum of 0.5 kg, in particular a minimum of 1 kg, in particular a minimum of 2 kg.

[0015] The processing device may have a user-operated control element, whereby, depending on the actuation of the control element, step c), in particular the procedure, can be triggered or executed.

[0016] The terms "include" or "have" can be used synonymously with the term "exhibits".

[0017] The term "sender" can be used synonymously with the term "sensor".

[0018] The term "recognize" can be used synonymously with the term "determine".

[0019] The position size can be initial and / or current and / or physical.

[0020] The position size, position, direction size and / or direction can have a value.

[0021] The position can be absolute and / or a rotational position.

[0022] The term "angular position" or "position" can be used synonymously with the term "position".

[0023] At standstill, a rotational speed of zero can mean zero.

[0024] The term "characteristic" can be used synonymously with the term "representative".

[0025] The term "choose" can be used synonymously with the term "determine".

[0026] The directional quantity can be physical.

[0027] The magnitude and / or direction can be, in particular at any given time, either clockwise or counterclockwise.

[0028] Continuous rotation can mean continuous and / or uninterrupted and / or without stopping and / or by at least 180° (degrees), in particular at least 360°, and / or to achieve a target rotational speed, in particular at least 10% (percent) of a rated rotational speed, of the rotor.

[0029] The term "rotate" can be used synonymously with the term "turn".

[0030] The direction can be a direction of rotation.

[0031] The term "based on" can be used synonymously with the term "depending on".

[0032] Theoretically, something can be reachable.

[0033] The term "starting torque" or "starting torque" can be used synonymously with the term "torque".

[0034] The term "affordable" can be used synonymously with the term "producible".

[0035] The term "reis" can be used synonymously with the term "brech".

[0036] The term "threshold" can be used synonymously with the term "border".

[0037] The breakaway torque limit can depend on a breakaway torque required, in particular a minimum one, especially in a proper and / or free-running or load-free, in particular unblocked or unjammed, state of the machining device, and / or be set or specified, in particular by the factory or manufacturer and / or fixed, in particular equal to or greater than the breakaway torque, and / or not be preset by a user.

[0038] The achievable torque can depend on the position, which may be fixed or unpredictable, and the direction, which can be determined, in particular, will be determined. Additionally or alternatively, the magnitude of the torque for rotation in, in particular at least, one of two possible directions can always be achieved, since the machining device, in particular the synchronous motor, can be designed or configured accordingly.

[0039] Depending on the position, the rotation can be determined either in a first direction, and in particular not in a second direction, or in the second direction, and in particular not in the first direction, or in the first direction or in the second direction, the second direction being opposite to the first direction.

[0040] In step b), the magnitude of the torque can be determined, but it is not necessary, and / or whether the magnitude of the torque for rotation in the direction is greater than the magnitude of the breakaway torque limit.

[0041] In step c), the synchronous motor can be controlled in the same way as in step b).

[0042] Step b) can be performed after step a). Additionally or alternatively, step c) can be performed after step b).

[0043] The control can be achieved by generating control voltages for the, in particular three, phases of the synchronous motor and / or by involving commutation, in particular commutation.

[0044] The terms "configured" or "set up" can be used synonymously with the term "trained".

[0045] In a further development of the invention, step b) comprises: determining the direction of rotation in the first direction, and in particular not in the second direction, if the determined position is representative of a first position range of possible rotor positions, particularly at least within a first position range. Within this first position range, the magnitude of the torque for rotation in the first direction is greater than, and in the second direction equal to or less than, the magnitude of the breakaway torque limit. The second direction is opposite to the first direction. This allows the determination to be simple and / or, in particular, fast. In particular, the term "sector" or "interval," especially "limited interval," can be used synonymously with the term "range."Additionally or alternatively, in step b) it can be determined whether the position size is in the first position size range or not.

[0046] In one embodiment of the invention, step b) comprises: determining the direction of rotation in the second direction, and in particular not in the first direction, if the determined position parameter is representative of a second position parameter range of possible rotor positions, particularly at least one. The second position parameter range is different from the first position parameter range, in particular completely so. In the second position parameter range, the magnitude of the torque for rotation in the second direction is greater than, and in the first direction equal to or less than, the magnitude of the breakaway torque limit.

[0047] Additionally or alternatively, step b) comprises: determining the direction of rotation, in particular either in the first direction or in the second direction, if the determined position is representative of a third position range of possible rotor positions, in particular at least a third position range. The third position range is distinct from the first position range, and in particular from the second position range, and in particular completely so. In the third position range, the magnitude of the torque for rotation in the first direction and in the second direction is greater than the magnitude of the breakaway torque limit.

[0048] This allows for easy and / or quick determination for any possible position.

[0049] In particular, step b) can determine whether the position size is in the second position size range or not, and / or in the third position size range or not.

[0050] In one embodiment of the invention, the first position range and / or the second position range and / or the third position range extend, in particular, each over a minimum of 1°, in particular a minimum of 2°, in particular a minimum of 5°, and / or a maximum of 180°, in particular a maximum of 120°, in particular a maximum of 60°. Additionally or alternatively, the first position range is one of several first position ranges and / or the second position range is one of several second position ranges and / or the third position range is one of several third position ranges. Furthermore, additionally or alternatively, the first position range is one of several first position ranges and / or the second position range is one of several second position ranges and / or the third position range is one of several third position ranges.In particular, the first position ranges / position size ranges, the second position ranges / position size ranges and / or the third position ranges / position size ranges can alternate.

[0051] In a further development, and in particular an embodiment, of the invention, step b) comprises: determining the direction of rotation in the first direction or in the second direction, wherein the second direction is opposite to the first direction, such that upon multiple or repeated execution of the method, the rotation in the first and second directions is uniformly distributed, particularly if the determined position is within the third position range. This enables uniform wear of the machining device, especially the synchronous motor. In particular, a distribution of rotation in the first and second directions can be stored such that the next determination can be carried out depending on the stored distribution.

[0052] In a further development of the invention, the processing device can be operated without a preferred direction of the rotor or without a preferred direction. In particular, the term "preference" can be used synonymously with the term "preferred".

[0053] In a further development of the invention, the processing device is a specialized harvester, in particular an olive shaker, or a hedge trimmer. Additionally or alternatively, the processing device comprises a non-rotating, in particular oscillating translational, tool, especially at least one rake. This allows the processing device to operate without a preferred direction of rotation of the rotor. In particular, the tool can be configured to move in two, in particular opposite, directions of movement. In other words, the tool can be configured to reverse the direction of movement or to move back and forth. Additionally or alternatively, the movement can describe the form of an open or non-closed curve. Furthermore, additionally or alternatively, the terms "reciprocal," "linear," or "oscillating" can be used synonymously with the term "translational."

[0054] In a further development of the invention, the processing device includes a conversion device, in particular a gearbox. The conversion device is designed to convert the rotation of the rotor into a non-rotating movement, in particular an oscillating translational movement. This allows the processing device to be without a preferred direction of rotation of the rotor and / or to be a special harvester or hedge trimmer and / or to include a non-rotating tool. Additionally or alternatively, the uniformly distributed rotation enables uniform wear of the conversion device. In particular, the gearbox can be mechanical and / or a linkage drive, in particular a crank drive. Additionally or alternatively, the conversion can be automatic.

[0055] In a further development of the invention, step a), in particular the method up to step c), is performed without rotating the rotor. Additionally or alternatively, step b) after step a) is performed directly and / or without an intermediate step. Furthermore, additionally or alternatively, step c) after step b) is performed directly and / or without an intermediate step and / or without stopping the rotor. This enables good and / or, in particular, user-friendly operation of the processing device when starting, disengaging, or rotating the synchronous motor. In particular, the term "direct" can be used synonymously with "immediately."

[0056] In a further development of the invention, the determination process involves measuring at least one inductance, in particular inductances, of the synchronous motor, especially the stator, using test signals, in particular an indirect flux determination by online reactance measurement (INFORM), a high-frequency square-wave injection, or an injection of a rotating or alternating test signal in a rotor- or stator-oriented coordinate system. This enables the determination to be reliable and / or fast. In particular, the inductance can be current and / or have a value. Additionally or alternatively, the test signals can be high-frequency and / or voltage test signals. In other words, the test signals can be chosen to be so short in their intensity and duration that they do not cause the rotor to rotate.For example, the test signals, in particular three, can be rectangular or sinusoidal test voltages, especially those that can be applied to the corresponding phases of the three-phase synchronous motor. Furthermore, or alternatively, the synchronous motor can have at least one voltage and / or current sensor for measuring, in particular, voltages and / or currents in the phases. For further information, please refer to the relevant technical literature.

[0057] In a further development of the invention, the position parameter is the position, determined in particular by calculation. Additionally or alternatively, the direction parameter is the direction, determined in particular by calculation. In particular, the position parameter range can be the position range.

[0058] In a further development of the invention, the amount of torque achievable by the synchronous motor during sensorless control is limited to a maximum permissible current amplitude of the synchronous motor. This prevents damage to the synchronous motor. In particular, the current amplitude can have a specific value. Additionally or alternatively, the term "rated current" can be used synonymously with "maximum permissible current amplitude".

[0059] The handheld processing device according to the invention comprises a permanent magnet synchronous motor and a control unit. The control unit is configured to execute a method, in particular the method described above. The processing device can offer the same advantages as described above for the method. In particular, the processing device can be configured as described above for the method. Additionally or alternatively, the control unit can be electrical and / or in the form of a microprocessor control. Furthermore, additionally or alternatively, the execution can be automatic. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Further advantages and aspects of the invention will become apparent from the claims and from the description of exemplary embodiments of the invention, which are explained below with reference to the figures. These show: Fig. 1 a flowchart of a method according to the invention for operating a permanent magnet synchronous motor of a hand-held processing device, Fig. 2 a schematic graph of an achievable torque achievable by the synchronous motor when sensorless controlled to rotate a rotor of the synchronous motor from a standstill in one direction over possible positions of the rotor, Fig. 3 the hand-held processing device according to the invention in the form of a special harvester when operating the synchronous motor, and Fig. 4 the hand-held processing device according to the invention in the form of a hedge trimmer when operating the synchronous motor. DETAILED DESCRIPTION OF THE EXECUTION EXAMPLES

[0061] Fig. 1 bis 4 Figure 1 shows a method according to the invention for operating a permanent magnet synchronous motor 2 of a hand-held processing device 1 and the hand-held processing device 1 according to the invention comprising the permanent magnet synchronous motor 2 and a control device 3. The control device 3 is designed to carry out the method, in particular, it carries out

[0062] The procedure comprises the following steps: a) sensorless determination of a position parameter POG representative of a position PO of a rotor 4 of the synchronous motor 2 at standstill, using the control device 3. b) Determination of a direction parameter RIG for continuous rotation of the rotor 4 from standstill in a direction RI as a function of the determined position parameter POG, such that an amount BDM of an achievable torque DM that can be generated by the synchronous motor 2 when sensorlessly driven to rotate in the direction RI is greater than an amount BLM of a breakaway torque limit LM of the processing device 1, as shown in Fig. 2 shown, using the control device 3. c) sensorless control of the synchronous motor 2 as a function of the determined direction variable RIG to rotate in the direction RI, using the control device 3.

[0063] In detail, step b) involves: Determining the direction variable RIG for rotation in a first direction RI1, if the determined position variable POG in a first position variable range POGB1 is representative of a first position range POB1 of possible positions of the rotor 4. In the first position range POB1, the magnitude BDM of the torque DM for rotation in the first direction RI1 is greater than, and in a second direction RI2 is equal to or less than, the magnitude BLM of the breakaway torque limit LM. The second direction RI2 is opposite to the first direction RI1.

[0064] Furthermore, step b) involves: Determining the direction variable RIG for rotation in the second direction RI2, if the determined position variable POG in a second position variable range POGB2 is representative of a second position variable range POB2 of possible positions of the rotor 4. The second position variable range POGB2 is different from the first position variable range POGB1. In the second position variable range POB2, the magnitude BDM of the torque DM for rotation in the second direction RI2 is greater than, and in the first direction RI1 is equal to or less than, the magnitude BLM of the breakaway torque limit LM.

[0065] Additionally or alternatively, step b) includes: Determining the direction variable RIG for rotation in the first direction RI1 or in the second direction RI2, if the determined position variable POG in a third position variable range POGB3 is representative of a third position variable range POB3 of possible positions of the rotor 4. The third position variable range POGB3 differs from the first position variable range POGB1, and in particular from the second position variable range POGB2. In the third position variable range POB3, the magnitude BDM of the torque DM for rotation in the first direction RI1 and in the second direction RI2 is greater than the magnitude BLM of the breakaway torque limit LM.

[0066] In detail, the first position area POB1 and / or the second position area POB2 and / or the third position area POB3 extend over a minimum of 1°, in particular a minimum of 2°, in particular a minimum of 5°, and / or a maximum of 180°, in particular a maximum of 120°, in particular a maximum of 60°.

[0067] Additionally or alternatively, the first position area POB1 is one of several first position areas POB1, four in the illustrated embodiment, and / or the second position area POB2 is one of several second position areas POB2, two in the illustrated embodiment, and / or the third position area POB3 is one of several third position areas POB3, five in the illustrated embodiment.

[0068] Furthermore, additionally or alternatively, the first position size range POGB1 is one of several first position size ranges POGB1, in the illustrated embodiment the four, and / or the second position size range POGB2 is one of several second position size ranges POGB2, in the illustrated embodiment the two, and / or the third position size range POGB3 is one of several third position size ranges POGB3, in the illustrated embodiment the five.

[0069] In the illustrated embodiment, the third position area POB3 / position size area POGB3, the second position area POB2 / position size area POGB2, the third position area POB3 / position size area POGB3, the first position area POB1 / position size area POGB1, the third position area POB3 / position size area POGB3, the second position area POB2 / position size area POGB2, the first position area POB1 / position size area POGB1, the third position area POB3 / position size area POGB3, the first position area POB1 / position size area POGB1, the third position area POB3 / position size area POGB3 and the first position area POB1 / position size area POGB1 alternate.

[0070] Furthermore, step b) includes: Determining the direction parameter RIG for rotation in the first direction RI1 or in the second direction RI2, wherein the second direction RI2 is opposite to the first direction RI1, such that when the procedure is executed multiple times, the rotation in the first direction RI1 and in the second direction RI2 is equally distributed, in particular if the determined position parameter POG is in the third position parameter range POGB3.

[0071] Furthermore, the processing device 1 can be operated without a preferred direction of the rotor 4.

[0072] Furthermore, the processing device 1 is a special harvester 1', in particular an olive shaker 1", as in Fig. 3 shown, or hedge shears 1‴, as in Fig. 4 shown.

[0073] Additionally or alternatively, the processing device 1 has a non-rotating, in particular oscillating translational, tool 5, in particular at least one rake 5', as in Fig. 3shown.

[0074] Furthermore, the machining device 1 has a conversion device 6, in particular a gearbox 6'. The conversion device 6 is designed to convert the rotation of the rotor 4 into a non-rotating movement, in particular an oscillating translational movement, especially of the tool 5, and in particular converts.

[0075] Furthermore, step a), in particular the procedure up to step c), is performed without rotating the rotor 4. Additionally or alternatively, step b) is performed after step a) without an intermediate step and / or directly. Furthermore, additionally or alternatively, step c) is performed after step b) without an intermediate step and / or directly and / or without stopping the rotor 4.

[0076] Furthermore, the determination involves measuring at least one inductance of synchronous motor 2 using test signals, in particular an indirect flux determination by online reactance measurement (INFORM), a high-frequency square wave injection, or an injection of a rotating or alternating test signal in a rotor- or stator-oriented coordinate system.

[0077] Furthermore, the position parameter POG is the position PO, determined in particular by calculation. Additionally or alternatively, the direction parameter RIG is the direction RI, determined in particular.

[0078] Furthermore, the amount BDM of the torque DM can be generated by the synchronous motor 2 when controlled without sensors with a maximum permissible current amplitude IA of the synchronous motor 2.

[0079] As the exemplary embodiments shown and explained above clearly demonstrate, the invention provides an advantageous method for operating a permanent magnet synchronous motor of a hand-held processing device and an advantageous hand-held processing device, each having improved properties.

Claims

1. Method for operating a permanently excited synchronous motor (2), wherein the method comprises the steps of: a) determining a position variable (POG) representative of a position (PO) of a rotor (4) of the synchronous motor (2) at a standstill, b) determining a direction variable (RIG) for a rotation of the rotor (4) from standstill in a direction (RI) on the basis of the determined position variable (POG) such that an absolute value (BDM) of an attainable torque (DM) that can be generated by the synchronous motor (2) during its actuation for the rotation in the direction (RI) is greater than an absolute value (BLM) of a breakaway torque limit (LM) of the working device (1), and c) actuating the synchronous motor (2) for the rotation in the direction (RI), - characterized in that - the synchronous motor () is of a hand-held working device (1), - the determination is sensorless, - the rotation is continuous, and - the actuation is sensorless and on the basis of the determined direction variable (RIG).

2. Method according to the preceding claim, - wherein step b) involves: determining the direction variable (RIG) for the rotation in a first direction (RI1) if the determined position variable (POG) is in a first position variable range (POGB1) representative of a first position range (POB1) of possible positions of the rotor (4), wherein, in the first position range (POB1), the absolute value (BDM) of the torque (DM) for the rotation in the first direction (RI1) is greater than, and in a second direction (RI2) is equal to or less than, the absolute value (BLM) of the breakaway torque limit (LM), wherein the second direction (RI2) is opposite the first direction (RI1).

3. Method according to the preceding claim, - wherein step b) involves: determining the direction variable (RIG) for the rotation in the second direction (RI2) if the determined position variable (POG) is in a second position variable range (POGB2) representative of a second position range (POB2) of possible positions of the rotor (4), wherein the second position variable range (POGB2) differs from the first position variable range (POGB1), wherein, in the second position range (POB2), the absolute value (BDM) of the torque (DM) for the rotation in the second direction (RI2) is greater than, and in the first direction (RI1) is equal to or less than, the absolute value (BLM) of the breakaway torque limit (LM), and / or - wherein step b) involves: determining the direction variable (RIG) for the rotation in the first direction (RI1) or in the second direction (RI2) if the determined position variable (POG) is in a third position variable range (POGB3) representative of a third position range (POB3) of possible positions of the rotor (4), wherein the third position variable range (POGB3) differs from the first position variable range (POGB1) and in particular the second position variable range (POGB2), wherein, in the third position range (POB3), the absolute value (BDM) of the torque (DM) for the rotation in the first direction (RI1) and in the second direction (RI2) is greater than the absolute value (BLM) of the breakaway torque limit (LM).

4. Method according to one of the two preceding claims, - wherein the first position range (POB1) and / or the second position range (POB2) and / or the third position range (POB3) extend(s) over a minimum of 1°, in particular a minimum of 2°, in particular a minimum of 5°, and / or a maximum of 180°, in particular a maximum of 120°, in particular a maximum of 60°, and / or - wherein the first position range (POB1) is one of a plurality of first position ranges (POB1) and / or the second position range (POB2) is one of a plurality of second position ranges (POB2) and / or the third position range (POB3) is one of a plurality of third position ranges (POB3), and / or - wherein the first position variable range (POGB1) is one of a plurality of first position variable ranges (POGB1) and / or the second position variable range (POGB2) is one of a plurality of second position variable ranges (POGB2) and / or the third position variable range (POGB3) is one of a plurality of third position variable ranges (POGB3).

5. Method according to one of the, in particular three, preceding claims, - wherein step b) involves: determining the direction variable (RIG) for the rotation in a first direction (RI1) or in a second direction (RI2), wherein the second direction (RI2) is opposite the first direction (RI1), such that, when the method is carried out multiple times, the rotation is equally distributed in the first direction (RI1) and in the second direction (RI2), in particular if the determined position variable (POG) is in the third position variable range (POGB3).

6. Method according to one of the preceding claims, - wherein the working device (1) can be operated without a preferred direction of the rotor (4).

7. Method according to one of the preceding claims, - wherein the working device (1) is a special harvester (1'), in particular an olive shaker (1"), or a hedge trimmer (1‴), and / or - wherein the working device (1) has a non-rotating, in particular oscillating translational, tool (5), in particular at least one rake (5').

8. Method according to one of the preceding claims, - wherein the working device (1) has a conversion device (6), in particular a gearbox (6'), wherein the conversion device (6) is designed to convert the rotation of the rotor (4) into a non-rotating movement, in particular an oscillating translational movement.

9. Method according to one of the preceding claims, - wherein step a), in particular the method up to step c), is without a rotation of the rotor (4), and / or - wherein step b) is after step a) without an intermediate step and / or immediately, and / or - wherein step c) is after step b) without an intermediate step and / or immediately and / or without a standstill of the rotor (4).

10. Method according to one of the preceding claims, - wherein the determination involves measuring at least one inductance of the synchronous motor (2) by means of test signals, in particular an indirect flux determination by online reactance measurement (INFORM), a high-frequency square-wave injection, or an injection of a rotating or alternating test signal in a rotor-oriented or stator-oriented coordinate system.

11. Method according to one of the preceding claims, - wherein the position variable (POG) is the position (PO), in particular determined by means of calculation, and / or - wherein the direction variable (RIG) is the direction (RI), in particular determined.

12. Method according to one of the preceding claims, - wherein the absolute value (BDM) of the torque (DM) that can be generated by the synchronous motor (2) can be achieved when the latter is sensorlessly actuated with at most a maximum permissible current amplitude (IA) of the synchronous motor (2).

13. Hand-held working device (1), wherein the working device (1) has: - a permanently excited synchronous motor (2), and - a control device (3), wherein the control device (3) is designed to carry out a method according to one of the preceding claims.