Adjustment device for a motor vehicle

Abstract

An adjustment device (1) for a motor vehicle (3) comprises: an electric motor (10, 10') with a stator (100, 100') and a rotor (101, 101') rotatable relative thereto, and a control unit (12, 12') which is configured to apply to a control signal (C1) an oscillation signal (V) aligned with an angle of rotation of the rotor (101, 101') relative to the stator (100, 100') in order to obtain a modified control signal (C2), and to operate the electric motor (10, 10') by means of the modified control signal (C2).

Description

[0001] The invention relates to an adjusting device for a motor vehicle, a vehicle seat and a vehicle with such an adjusting device, a method for operating an adjusting device and a computer-readable memory.

[0002] Motorized adjustment devices are becoming increasingly important in vehicle construction. For example, vehicle seats, doors, window lifts, tailgates, etc. are now frequently equipped and operated with adjustment devices.

[0003] Vehicle seats can be adjustable, e.g. to enable different seat users to achieve a comfortable seating position and to be adapted to different space conditions. For example, a vehicle seat can be mounted in a vehicle so that it can be adjusted lengthwise using a longitudinal adjustment mechanism in order to enable different seating positions along the vehicle's longitudinal axis, a vehicle seat can be adjustable using a height adjustment device in order to set the seat height, and in a vehicle seat the inclination of a backrest relative to a seat part can be adjustable, to name just a few examples. One or more manual or motorized drive systems can be provided to make such adjustments. Motorized adjustment devices allow the settings to be made easily, e.g. by pressing buttons, or even completely automatically.

[0004] Motorized adjustment devices typically generate noise during the adjustment process, which can sometimes be perceived as annoying. In the automotive sector, it is desirable to minimize the generation of disturbing noise.

[0005] The task is to provide an adjustment device that allows the development of disturbing noises to be reduced.

[0006] This object is achieved by an article having the features of claim 1.

[0007] According to this, an adjustment device for a motor vehicle comprises an electric motor with a stator and a rotor rotatable relative thereto, and a control unit. The control unit is configured to apply a vibration signal aligned with a rotation angle of the rotor relative to the stator to a control signal in order to obtain a modified control signal, and to operate the electric motor using the modified control signal.

[0008] This is based on the knowledge that harmonics caused by commutation (mechanical or electronic) of the electric motor are perceived as particularly disturbing in the operation of adjustment devices because they can result in noise components in the range of 1 to 2 kHz at typical adjustment speeds. Measurements have shown that, for example, in an electric motor in the form of a brushless direct current motor (BLDC motor), errors in the zero crossing of the phase currents caused by a dead time in electronic switches or harmonic errors in the back electromotive force (also known as back EMF) can, depending on the number of pole pairs (e.g. 3) of the electric motor, result in an increased harmonic oscillation of the 18th order. At an example speed of 6000 RPM, corresponding to a rotational frequency of 100 Hz, this leads to a component at 1800 Hz that is usually perceived as disturbing.A similar phenomenon has been observed in DC motors, where current and torque fluctuations at lamination transitions in DC self-commutation were identified as the cause. By imposing the vibration signal, which is aligned with the angle of rotation of the rotor relative to the stator, on the control signal for the electric motor, the aforementioned causes of noise development can be effectively counteracted. In this way, vibrations are imposed on the rotor, which can counteract the vibrations that cause the noises perceived as disturbing. The adjustment device thus makes it possible to reduce the development of disturbing noises. The adjustment device is used, for example, to set a position of one component relative to another (e.g. a predetermined position and / or one entered via a command).

[0009] The control signal is configured to set the electric motor in motion. The modified control signal is configured to set the electric motor in motion and additionally generate a mechanical vibration by means of the electric motor and / or prevent the generation of a mechanical vibration.

[0010] The control unit can be configured to determine at least one vibration parameter based on at least one current operating parameter of the electric motor and to generate the vibration signal to be applied based on the determined vibration parameter. This allows for dynamically optimized noise reduction.

[0011] For example, the at least one vibration parameter includes an amplitude and / or a phase and / or a frequency of the vibration signal. The phase indicates, for example, the offset relative to the rotor's rotation angle. This allows for effective noise reduction.

[0012] The at least one current operating parameter includes, for example, a direction of rotation and / or a speed of the electric motor and / or a position of a component adjustable by the adjustment device. It has been shown that noise development can depend particularly on these operating parameters; therefore, taking them into account allows for effective noise reduction.

[0013] The adjustment device can further comprise a sensor configured, for example, to provide the at least one current operating parameter to the control unit. This allows a precise basis for determining the vibration signal to be obtained. Alternatively or additionally, the control unit can determine at least one operating parameter, for example, based on electrical variables.

[0014] The sensor is designed, for example, as a seat occupancy sensor or a weight sensor. The at least one current operating parameter can therefore describe a seat occupancy or a weight. It has been shown that the development of disturbing noises can be strongly dependent on load. By adapting the properties of the vibration signal to the load, noise reduction can be improved. For example, in the case of a vehicle seat, the properties of the vibration signal can be adapted to the occupancy of the seat by a passenger and / or even to a measured weight acting on the vehicle seat.

[0015] A characteristic curve or characteristic map can be stored in the control unit, which assigns the at least one vibration parameter to the at least one current operating parameter. The control unit can then read the vibration parameter(s) from the characteristic curve or characteristic map in a particularly simple manner based on the one or more current operating parameters. The vibration signal can then be generated and applied by the control unit according to the read vibration parameter(s).

[0016] For example, the control unit is configured to determine the current flowing through the electric motor and generate the vibration signal based on the determined current. A load-dependent vibration signal can also be applied in this way.

[0017] The adjustment device may further comprise a power supply unit configured to receive the control signal and / or the modified control signal and to supply an electric current to the electric motor based on the control signal and / or the modified control signal. The supplied electric current sets the electric motor in motion.

[0018] The electrical current provided by the power supply unit includes, in particular, a current oscillation and / or voltage oscillation corresponding to the oscillation signal. This then prevents, for example, the generation of mechanical oscillation, thereby counteracting disturbing noises.

[0019] For example, the electric motor is designed as a brushless direct current (BLDC) motor. The power supply unit can be designed, for example, as an electronic inverter. BLDC motors enable high adjustment precision while maintaining a compact size.

[0020] Alternatively, the electric motor can be designed as a DC motor with sliding contacts (e.g., brushes). Such motors can be provided with a simple design and low manufacturing costs.

[0021] The adjustment device can further comprise a rotation angle sensor. The rotation angle sensor is configured, for example, to measure the rotation angle of the rotor relative to the stator (e.g., with respect to a preset or adjustable zero point) and provide it to the control unit. This enables a high degree of accuracy for the vibration signal.

[0022] According to one aspect, a vehicle seat is provided with a seat part, a backrest, and an adjustment device according to any embodiment described herein. Regarding the advantages, reference is made to the above information.

[0023] In the case of the vehicle seat, the adjustment device can be configured, for example, to drive a fitting arrangement for adjusting an inclination of the backrest to the seat part, to drive a longitudinal adjustment mechanism for longitudinally adjusting the vehicle seat relative to a ground or to drive a height adjustment mechanism for adjusting a seat height of the vehicle seat relative to the ground.

[0024] According to one aspect, a vehicle is provided with an adjustment device according to any embodiment described herein. With regard to the advantages, reference is again made to the above information. Alternatively or additionally, the vehicle may comprise the vehicle seat described above in any embodiment.

[0025] In the vehicle, the adjustment device can be designed to drive a door, a tailgate, a window lifter or a window pane.

[0026] According to one aspect, a method for operating an adjusting device for a motor vehicle, comprising an electric motor with a stator and a rotor rotatable relative thereto, and a control unit, is specified. The method comprises the following steps: providing a control signal; impressing a vibration signal aligned with a rotation angle of the rotor relative to the stator onto the control signal in order to obtain a modified control signal; and operating the electric motor using the modified control signal. In the method, the adjusting device can be used according to any embodiment described herein. With regard to the advantages, reference is again made to the above information.

[0027] According to one aspect, a computer-readable memory is provided, comprising instructions which, when executed by a processor arrangement of a control unit of an adjusting device comprising an electric motor with a stator and a rotor rotatable thereto, cause the control unit to carry out the method described above.

[0028] The attached figures illustrate possible embodiments of the proposed solution.

[0029] Here we show: Fig. 1 a motor vehicle with a motor-adjustable vehicle seat, a motor-openable tailgate, a motor-openable door and a motor-adjustable window; Fig. 2 an adjustment device for the motor vehicle according to Fig. 1; Fig. 3 a control signal and a modified control signal of a control unit of the adjustment device according to Fig. 2; Fig. 4 an adjustment device for the motor vehicle according to Fig. 1; Fig. 5 a measuring arrangement for measuring noise when adjusting the vehicle seat according to Fig. 1; and Fig. 6 Measurement results of the measurement arrangement according to Fig. 3.

[0030] Fig. 1 shows a motor vehicle 3, for example in the form of a passenger car. The motor vehicle 3 comprises several vehicle seats 2, of which Fig. 1 one is shown.

[0031] The vehicle seat 2 comprises a seat part 20 and a backrest 21. The backrest 21 is pivotable relative to the seat part 20 by means of a fitting arrangement 22. The fitting arrangement 22 includes inclination adjustment fittings. In the example shown, the backrest 21 is pivotably mounted on the seat part 20.

[0032] Furthermore, the vehicle seat 2 comprises a longitudinal adjustment mechanism 23. By means of the longitudinal adjustment mechanism 23, the seat part 20 and the backrest 21 are displaceable along a longitudinal axis. For this purpose, the longitudinal adjustment mechanism 23 comprises two pairs of rails, one pair of which is shown in the side view of the Fig. 1 is visible. A second pair of rails runs parallel to the first pair (and spaced apart from the first pair along a lateral axis; the lateral axis runs perpendicular to the longitudinal axis). A floor rail from each of the pairs is fastened to a base, here in the form of a vehicle floor 30 of the vehicle 3. On each of the floor rails, a seat rail is guided so as to be displaceable along the respective floor rail. The seat part 20 is supported on the seat rails, in the example shown via an (optional) height adjustment mechanism 24. The seat part 20 is mounted on the seat rails (here height-adjustable).

[0033] By means of the height adjustment mechanism 24, a seat height (along a height axis which runs perpendicular to the longitudinal axis and perpendicular to the lateral axis) of the seat part 20, in the present example including the backrest 21, can be adjusted.

[0034] The illustrated configuration of the vehicle seat 2 is merely exemplary, and the vehicle seat 2 may include other or additional adjustable mechanisms. The fitting assembly 22, the longitudinal adjustment mechanism 23, and the height adjustment mechanism 24 (alternatively or additionally, one or more other adjustment mechanisms of the vehicle seat 2) each comprise an adjustment device 1.

[0035] The vehicle seat 2 can further comprise one or more sensors and, here, for example, comprises a seat occupancy sensor 15 and a weight sensor 16. The seat occupancy sensor 15 outputs a signal indicating whether the vehicle seat 2 is occupied or not. The signal from the seat occupancy sensor 15 can be a binary signal. The weight sensor 16 outputs a signal indicating a weight acting on the weight sensor 16. In the present case, the weight sensor 16 is mounted such that the weight of a passenger sitting on the vehicle seat 2 acts on it. Therefore, in the example shown, the weight sensor 16 outputs a signal indicative of the passenger's weight.

[0036] The motor vehicle 3 further comprises a door 31, which can be opened and closed by means of an adjusting device 1. In addition, the motor vehicle 3 comprises a tailgate 32, which can be opened and closed by means of an adjusting device 1. Furthermore, the motor vehicle 3 comprises a window lifter 33 with an adjusting device 1 for opening and closing a window pane 34 (in the present example, the door 31). The illustrated embodiment of the motor vehicle 3 is merely exemplary, and the motor vehicle 3 can be designed without the door 31, the tailgate 32 and / or the window lifter 33 and / or with or without the respective adjusting device 1. Furthermore, the motor vehicle 3 can also comprise adjusting devices 1 for other adjustable components.

[0037] Each of the adjustment devices 1 can, for example, be Fig. 2 or according to Fig. 4 be trained.

[0038] Fig. 2 shows an example of one of the adjustment devices 1 of the motor vehicle 3.

[0039] The adjustment device 1 comprises an electric motor 10 with a stator 100 and a rotor 101 rotatable thereto. The electric motor 10 is in the assembled state according to Fig. 1 is attached to the corresponding adjustment mechanism. The stator 100 is then fixed relative to a part of the corresponding adjustment mechanism. In the example of the longitudinal adjustment mechanism 23, the electric motor 10 is fixed relative to the seat rails, although other configurations are also conceivable.

[0040] The rotor 101 is operatively connected to a shaft 13. The rotor 101 drives the shaft 13. For example, the rotor is connected to the shaft in a rotationally fixed manner or, as in Fig. 2, coupled to it via a gear 11. In the example of the Fig. 2, the adjustment device 1 thus comprises the gear 11, but gearless direct drives are also conceivable. The adjustment device 1 serves as the drive for the respective adjustment mechanism. An adjustment system comprises the respective adjustment mechanism and the adjustment device 1.

[0041] The electric motor 10 is embodied here, for example, as a direct current motor. If a direct voltage is applied to the electric motor 10, a current flow through the electric motor 10 causes the rotor 101 to rotate relative to the stator 100 about a rotational axis of the rotor 101. Here, for example, the stator 100 comprises permanent magnets (alternatively, a stator winding is provided which is supplied with a direct voltage). The rotor 101 comprises a wire winding which is supplied with the applied direct voltage via sliding contacts 102. Depending on the rotational position of the rotor 102 relative to the stator 100, the current flow through the wire winding is reversed. The electric motor 10 therefore comprises mechanical commutation. The sliding contacts 102 comprise brushes, for example.

[0042] The adjustment device 1 further comprises a control unit 12. The control unit 12 is configured to use control signals C1, C2 to apply the direct voltage to the electric motor 10. In the present case, it is provided, by way of example, that the control unit 12 comprises a processor arrangement 120 (with one or more processors) and a (computer-readable) memory 121 communicatively connected thereto. The processor arrangement 120 is configured to generate the control signals C1, C2 and / or read them from the memory 121. The processor arrangement 120 applies the control signals C1, C2 to a power supply unit 122. In a particularly simple case, the power supply unit 122 comprises or consists of a transistor. The transistor (or one or more other electronic components) then applies the direct voltage, illustrated here with + and -, to the electric motor 10.For example, the power supply unit 122 determines the voltage and / or current of the applied DC voltage based on the control signals C1, C2. The control signals C1, C2 thus indicate, for example, a voltage and / or a current.

[0043] The memory 121 also stores instructions 123 that can be executed by the processor arrangement 120. Furthermore, a characteristic map 124 is stored in the memory, which will be explained in more detail below.

[0044] The adjustment device 1 further comprises a rotation angle sensor 14. The rotation angle sensor 14 is arranged on the electric motor 10. The rotation angle sensor 14 is configured to measure a rotation angle of the rotor 101 relative to the stator 100 and to provide it to the control unit 12 in the form of an angle signal. In other words, the rotation angle sensor 14 generates an angle signal depending on the rotation angle of the rotor 101 relative to the stator 100. The angle signal indicates, for example, an angle of 0° to 360° (in relation to a predetermined or predefinable zero point position). Alternatively, the angle signal (only) indicates whether the rotor 101 is arranged at a certain angular position relative to the stator 100 or not. The control unit 12 can then calculate the absolute angular position of the rotor 101 based on this signal and the current rotational speed. More than one rotation angle sensor 14 can also be provided.

[0045] Fig. Figure 3 shows an example of a control signal C1, a periodic oscillation signal V, and a modified control signal C2. For the sake of simplicity, the control signal C1 is a voltage with a constant amplitude A over time t, in Fig. 3 is represented by a dashed line. This allows the electric motor 10 to rotate at a constant speed. Of course, other control signals are also conceivable for different operating modes (e.g., starting or braking) or other motor types.

[0046] The control unit 12 is configured to apply the oscillation signal V, which is aligned with the angle of rotation of the rotor 101 relative to the stator 100, to the control signal C1 in order to obtain the modified control signal C2. The oscillation signal V has a signal shape, here, for example, in the form of pulses spaced apart in time, alternatively or additionally in the form of a sinusoidal oscillation or the like. The control signal C1 and the oscillation signal V each have an amplitude A. Furthermore, the oscillation signal V has a frequency. The frequency is, for example, equal to the rotational frequency of the rotor 101 or an integer multiple thereof, or the rotational frequency is an integer multiple of the frequency of the oscillation signal V. In the example of the Fig. 3, the oscillation signal V has a frequency equal to the rotational frequency of the rotor 101. One revolution U of the rotor 101 begins at time t0 and is completed at time t1. The next revolution U therefore begins at time t1. For each revolution U, the oscillation signal V has one pulse (here, one harmonic and one subharmonic). Alternatively, it can be provided that the oscillation signal V comprises, for example, two, three, or more pulses (e.g., each with one harmonic and / or one subharmonic) per revolution U.

[0047] Furthermore, the oscillation signal V has a phase. The phase defines the temporal offset of the oscillation signal V from the beginning of a respective revolution U (e.g., 0° to 20° or, specifically, 10°). The oscillation signal V is thus described by one or more oscillation parameters, wherein the one or more oscillation parameters include the amplitude A, the phase, and / or the frequency.

[0048] The control unit 12 is configured to determine at least one vibration parameter based on at least one current operating parameter of the electric motor 10 and to generate the vibration signal V to be impressed based on the determined vibration parameter. The at least one current operating parameter comprises, for example, a direction of rotation and / or a speed of the electric motor 10 and / or a position of the component(s) adjustable by means of the adjustment device 1 (e.g., the seat rails relative to the floor rails). Depending on the direction of rotation and / or the speed, a differently designed vibration signal may achieve better results or, for example, it may only be necessary to impress a vibration signal in certain operating situations and not in others, e.g., when raising the seat height with one direction of rotation of the electric motor 10, but not when lowering it with the other direction of rotation.

[0049] Furthermore, using the example of the vehicle seat 2, the noise development can depend on whether a passenger is sitting on it and / or how heavy this person is. Therefore, by way of example, it is provided here that the control unit 12 is communicatively connected to at least one sensor which is configured to provide at least one current operating parameter to the control unit 12, specifically here to the seat occupancy sensor 15 and / or the weight sensor 16. The at least one current operating parameter then describes a seat occupancy or a weight. The sensors mentioned are merely examples, and other or additional sensors, e.g. an interior sensor system, can be used, for example an occupant detection sensor permanently mounted in the vehicle.

[0050] Alternatively or additionally, the control unit 12 may be configured to determine the current flowing through the electric motor 10 and to generate and / or select the vibration signal V based on the determined current. For example, the current depends on the applied load, which in turn determines the noise generation.

[0051] The aforementioned characteristic map 124 is stored in the control unit 12, for example. This map assigns the at least one vibration parameter to the at least one current operating parameter. For example, a table may be provided, and the control unit 12 reads the vibration parameter(s) from one or more fields of the table that correspond to the current operating parameter(s).

[0052] Alternatively or additionally, it can be provided that the control unit 12 stores and applies at least one formula to calculate the vibration parameter(s). The (or each) formula links, for example, a vibration parameter with one or more operating parameters. For example, the formula can be used to calculate the amplitude and phase from the current strength. For example, the amplitude is calculated using a straight-line equation, e.g., depending on the load or a current strength, e.g., the actuator current. If the phase is also adjusted, this could also be approximated using a polynomial or similar.

[0053] In a particularly simple embodiment, it can be provided that the control unit 12 stores fixed vibration parameters (e.g. amplitude and / or phase) for the most frequently used operating points (e.g. up to 5, up to 10 or up to 20 operating points). An operating point is defined, for example, by the operating parameters. This also makes it possible to provide an adapted vibration signal V depending on the load, torque modulation by the gearbox and kinematics, raising or lowering and / or for different speeds. It has been shown that certain adjustment devices can have characteristic vibrations, e.g. as a result of a gear ratio of a gear of the adjustment device, or based on certain positions, e.g. a lever angle. The vibration signal can be based, for example, on the gear ratio. In another example, a motor shaft can rotate more easily between 0° and 90° and more difficultly between 180° and 270°.This can be compensated for by a corresponding vibration signal. In one embodiment, vibration signals with an integer divisor are used to compensate for effects in a gear stage.

[0054] The control unit 12 is configured, for example, to impress the vibration signal V onto the control signal C1 by the control unit 12 (e.g. the processor arrangement 120) adding the vibration signal V to the control signal C1.

[0055] Furthermore, the control unit 12 is configured to operate the electric motor 10 using the modified control signal C2. For this purpose, the control unit 12, for example, applies the modified control signal C2 to the power supply unit 122. With a DC motor, it is possible to dispense with a current control loop.

[0056] The power supply unit 122 is configured to receive the modified control signal C2 and to provide an electric current to the electric motor 10 based on the modified control signal C2. The electric current provided by the power supply unit 122 includes a current oscillation and a voltage oscillation corresponding to the oscillation signal V.

[0057] The vibration signal V is aligned with the angle of rotation of the rotor 101 relative to the stator 100. As a result, the vibration signal V periodically generates a mechanical vibration at the same angle of rotation (or at each of several angles of rotation) of the rotor 101 relative to the stator 100.

[0058] It should be noted that the power supply unit 122 may be part of the control unit 12 or alternatively may be formed separately therefrom.

[0059] The control unit 12 receives a control command, e.g., with a target position or with a distance to be traveled along the respective adjustment path. Furthermore, the control command can specify an adjustment speed and / or an adjustment direction. The control command can, for example, be based on a user input or be automatically generated and transmitted to the control unit 12. The control unit 12 interprets this control command and operates the electric motor 10 accordingly.

[0060] Fig. 4 shows an example of a further possible embodiment of the adjustment device 1 with a control unit 12', an energy regulation unit 122' and an electric motor 10'.

[0061] The electric motor 10' is embodied, for example, in the form of a BLDC motor. The power supply unit 122' is embodied in the form of an inverter. This has several, here six, switches S1-S6, each of which is embodied, for example, in the form of a semiconductor switch. Each of the three coil windings, here for example, for a respective phase U, V, W, is connected between two respective switches S1 and S2, S3 and S4, or S5 and S6. Of the two respective switches S1 and S2, S3 and S4, or S5 and S6, one is connected to a terminal (+) and the other to another terminal (-) of a DC voltage supply. For example, +12 V and 0 V are present at the terminals of the DC voltage supply.

[0062] The control unit 12' controls the states of the switches S1-S6 (selectively opening and closing them). Furthermore, the control unit 12' receives angle signals from one or more rotation angle sensors 14, as described above. The angle signals are indicative of the rotation angle of the rotor 101' of the electric motor 10' relative to the stator 100'.

[0063] The control unit 12' controls or regulates the electric motor 10', e.g., based on sinusoidal commutation. For example, the control unit 12' applies control signals in the form of PWM signals (PWM: pulse width modulation) to the inverter, resulting in, for example, sinusoidal phase currents U, V, W that are phase-shifted by 120°. The control unit 12' generates a corresponding PWM control signal based on the respective control command. The inverter is controlled by the PWM control signal, causing the rotor 101' to rotate. In a closed control loop, the control unit 12' detects the resulting rotation of the rotor 101' based on the angle signals and adjusts the PWM control signal accordingly if there is a deviation from a target value of the angle of rotation or a variable derived therefrom. Alternatively, control without feedback can be provided.

[0064] As mentioned above in connection with Fig. 2 and Fig. 3, the control unit 12' is according to Fig. 4 is configured to apply a vibration signal aligned to the angle of rotation of the rotor 101' relative to the stator 100' to the control signal (here in the form of the PWM signal) in order to obtain a modified control signal and to operate the electric motor 10' using the modified control signal. In this example, the vibration signal can also be generated as a PWM signal, according to which the control signal is modified. For example, according to the vibration signal, the pulse width of individual or multiple PWM pulses is increased or decreased and / or PWM pulses are removed or added, wherein the changes to the PWM signal are aligned to the same angle of rotation over several revolutions. In this way, a periodic mechanical vibration can be generated, which counteracts the disturbing noise-generating vibration.

[0065] The design of the vibration signal can be as described above in connection with Fig. 2 and Fig. 3 should be provided.

[0066] Fig. 5 illustrates an exemplary measuring arrangement 4, by means of which the results of the imprinting of the vibration signals V can be measured and based on this the vibration signals V can be optimized.

[0067] The measuring arrangement 4 comprises the vehicle seat 2 (or another device to be measured with the adjustment device 1), a microphone 40 and an evaluation unit 41.

[0068] For the measurement, an adjustment is effected in a first pass, e.g., of the longitudinal adjustment mechanism 23, without imparting vibration signals V. The adjustment is thus performed based on the unmodified control signals S1. The microphone 40 records the resulting noise as the first result R1.

[0069] In a second pass, the adjustment is effected in the same way, with the only difference being that the vibration signals V are applied. The adjustment is thus performed using the modified control signals S2. Microphone 40 again records the resulting noise as the second result R2.

[0070] In this example, the oscillation signal V has an amplitude of 30 mV and a phase of 10°.

[0071] The evaluation unit 41 evaluates the recorded sounds. For example, the evaluation unit 41 performs a frequency analysis.

[0072] Fig. Figure 6 illustrates the sound pressure level (SPL) determined by the evaluation unit 41 over a frequency range from 400 to 1500 Hz for the first result R1 and the second result R2.

[0073] In particular, in the range of the 9th harmonic (at 450 Hz) and the 18th harmonic (at 900 Hz) of this example (with, for example, three phases and three pole pairs each, where deficiencies can occur twice per sinusoidal oscillation), sound pressure reductions of up to 10 dB have been achieved. This corresponds to a very clearly audible reduction in disturbing noises. Depending on the design of the control unit 12, 12', this improvement is possible by appropriately adapting the instructions 123 in the memory 121, i.e., without additional components. In particular, cancellation of the main harmonic of the commutation, cancellation of several harmonics simultaneously, and cancellation of mechanical influences can be achieved.

[0074] A method for operating an adjustment device 1 for a motor vehicle 3, comprising an electric motor 10, 10' (with a stator 100, 100' and a rotor 101, 101' rotatable relative thereto) and a control unit 12, 12' comprises providing a control signal C1 (e.g., this is provided or selected or calculated by an input control command), see the dashed line in Fig. 3; the imprinting of an oscillation signal V aligned with a rotation angle of the rotor 101, 101' relative to the stator 100, 100' on the control signal C1 in order to obtain a modified control signal C2, see the solid line in Fig. 3; and the operation of the electric motor 10, 10' by means of the modified control signal C2, see Fig. 2, Fig. 4 and Fig. 6.

[0075] The instructions 123 of the computer-readable memory 121 cause the control unit 12, 12' to execute this method when they are executed by the processor arrangement 120 of the control unit 12, 12' of the adjustment device 1. List of reference symbols 1 adjustment device 10, 10' electric motor 100, 100' stator 101, 101' Rotor 102 sliding contact 11 gearboxes 12, 12' control unit 120 processor arrangement 121 storage 122, 122' power supply unit 123 instructions 124 map 13 Wave 14 Angle sensor 15 Sensor (seat occupancy sensor) 16 Sensor (weight sensor) 2 vehicle seats 20 Seat part 21 Backrest 22 Fitting arrangement 23 Longitudinal adjustment mechanism 24 Height adjustment mechanism 3 Motor vehicle 30 Vehicle floor 31 Door 32 tailgate 33 window regulators 34 window pane 4 Measuring arrangement 40 microphones 41 Evaluation unit A Amplitude C1, C2 control signal R1, R2 first, second result S1-S6 switch t time t0, t1 time U revolution V vibration signal

Claims

[1] Adjusting device (1) for a motor vehicle (3), comprising: - an electric motor (10, 10') with a stator (100, 100') and a rotor (101, 101') rotatable thereto and - a control device (12, 12') which is designed to impress a vibration signal (V) aligned with a rotation angle of the rotor (101, 101') relative to the stator (100, 100') onto a control signal (C1) in order to obtain a modified control signal (C2), and to operate the electric motor (10, 10') by means of the modified control signal (C2). [2] Adjusting device (1) according to claim 1, characterized by that the control unit (12, 12') is configured to determine at least one vibration parameter based on at least one current operating parameter of the electric motor (10, 10') and to generate the vibration signal (V) to be impressed based on the determined vibration parameter. [3] Adjusting device (1) according to claim 2, characterized bythat the at least one vibration parameter comprises an amplitude and / or a phase. [4] Adjusting device (1) according to claim 2 or 3, characterized by that the at least one current operating parameter comprises a direction of rotation and / or a speed of the electric motor (10) and / or a position of a component adjustable by means of the adjusting device (1). [5] Adjusting device (1) according to one of claims 2 to 4, characterized by a sensor (14, 15) which is configured to provide the at least one current operating parameter to the control unit (12, 12'). [6] Adjusting device (1) according to claim 5, characterized by that the sensor (14, 15) is designed in the form of a seat occupancy sensor or in the form of a weight sensor, wherein the at least one current operating parameter describes a seat occupancy or a weight. [7] Adjusting device (1) according to one of claims 2 to 6, characterized bythat a characteristic map (124) is stored in the control unit (12, 12') which assigns the at least one vibration parameter to the at least one current operating parameter. [8] Adjusting device (1) according to one of the preceding claims, characterized by that the control device (12, 12') is configured to determine a current intensity of a current flowing through the electric motor (10, 10') and to generate the oscillation signal (V) based on the determined current intensity. [9] Adjusting device (1) according to one of the preceding claims, characterized by a power supply unit (122, 122') configured to receive the modified control signal (C2) and to provide an electric current to the electric motor (10, 10') based on the modified control signal (C2). [10] Adjusting device (1) according to claim 9, characterized bythat the electrical current provided by the power supply unit (122, 122') comprises a current oscillation and / or voltage oscillation corresponding to the oscillation signal (V). [11] Adjusting device (1) according to claim 9 or 10, characterized by that the electric motor (10') is designed in the form of a brushless DC motor, wherein the power supply unit (122') is designed in the form of an inverter. [12] Adjusting device (1) according to one of claims 1 to 10, characterized by that the electric motor (10) is designed in the form of a DC motor with sliding contacts (102). [13] Adjusting device (1) according to one of the preceding claims, characterized by a rotation angle sensor (14) which is configured to measure the rotation angle of the rotor (101, 101') relative to the stator (100, 100') and to provide it to the control unit (12, 12'). [14] Vehicle seat (2) with a seat part (20) and a backrest (21), characterized by an adjusting device (1) according to one of the preceding claims. [15] Vehicle seat (2) according to claim 14, characterized by that the adjusting device (1) is designed to drive a fitting arrangement (22) for adjusting an inclination of the backrest (21) to the seat part (20), to drive a longitudinal adjustment mechanism (23) for longitudinally adjusting the vehicle seat (2) relative to a ground or to drive a height adjustment mechanism (24) for adjusting a seat height of the vehicle seat (3) relative to the ground. [16] Vehicle (3), characterized by the adjusting device (1) according to one of claims 1 to 13. [17] Vehicle (3) according to claim 16, characterized by that the adjusting device (1) is designed to drive a door (31), a tailgate (32), a window lifter (33) or a window pane (34). [18] Method for operating an adjusting device (1) for a motor vehicle (3), comprising an electric motor (10, 10') with a stator (100, 100') and a rotor (101, 101') rotatable relative thereto and a control unit (12, 12'), the method comprising the following steps: - Providing a control signal (C1); - Impressing an oscillation signal (V) aligned with a rotation angle of the rotor (101, 101') relative to the stator (100, 100') onto the control signal (C1) to obtain a modified control signal (C2); and - Operating the electric motor (10, 10') by means of the modified control signal (C2). [19] Computer-readable memory (121) comprising instructions (123) which, when executed by a processor arrangement (120) of a control unit (12, 12') of an adjusting device (1) for a motor vehicle (3) comprising an electric motor (10, 10') with a stator (100, 100') and a rotor (101, 101') rotatable thereto, cause the control unit (12, 12') to carry out the method according to claim 18.

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