Method for adjusting the parameters of a controller for micromechanical actuators and device

Abstract

Method for adjusting the parameters (13-1 - 13-n) of a controller (2) for micromechanical actuators (3), comprising the steps: Applying (S1) to the micromechanical actuator (3) a test signal (5) which has a jump and / or pulse and / or a frequency sweep (6); Detecting (S2) a test signal response (8) of the micromechanical actuator (3) to the test signal (5); Identifying (S3) an absolute position (10) of at least one mode (11-1 - 11-3) in the acquired test signal response (8); and Adjusting (S4) at least one of the parameters (13-1 - 13-n) of the controller (2) based on the identified absolute position (10) of the at least one mode (11-1 - 11-3); and with the next step: Determining (S5) a relative position (14) of the modes (11-1 - 11-3) to each other in the acquired test signal response (8); and with the next step: Detecting (S6) at least one phase shift (15-1) or at least one phase jump (16-1 - 16-2) in the frequency response of the micromechanical actuator (3) based on the detected test signal response (8); wherein during the adaptation (S4) the at least one parameter (13-1 - 13-n) is adapted based on the identified absolute position (10) of the at least one mode (11-1 - 11-3) and the relative position (14) of the modes (11-1 - 11-3) in the acquired test signal response (8) to one another and the detected phase rotations (15-1) or the detected phase jumps.

Description

The present invention relates to a method for adapting the parameters of a controller for micromechanical actuators and a corresponding device.Prior ArtMicromechanical actuators are nowadays used in a large number of applications. For example, micromirrors are used in projector units which are intended to be constructed in a very small installation space.Micromirrors which represent a so-called MEMS-micro-electro-mechanical system-are usually used in such projector units. Such MEMS mirrors often have a plurality of mechanical resonance points-also called modes or pole points in the transfer function-which can be correspondingly electrically excited. Furthermore, such MEMS mirrors also have antiresonant modes-also called zeros in the transfer function or notch.The modes of the MEMS mirrors are divided here into usable modes and interfering modes. In particular, the excitation of spurious modes negatively affects the quality of the projected image.The MEMS mirrors mentioned form a so-called inertial spring-mass system, which can be modeled as a second-order low-pass filter (PT2 element) to a first approximation. The corner frequencies of the inertial spring-mass system are defined by its first mode.Such a MEMS mirror can be operated either resonantly on one or more usable modes or quasi-statically. The quasi-static actuation takes place with a low-frequency signal and avoids excitation of the modes.For the image construction with the aid of MEMS mirrors, two MEMS mirrors are usually required, wherein one of the MEMS mirrors is resonantly driven and one of the MEMS mirrors is operated quasi-statically. In this case, the resonantly operated MEMS mirror is responsible for the line projection of the image, and the quasistatically operated MEMS mirror is responsible for the line-by-line image construction.Usually, a MEMS mirror is driven with a sawtooth signal in order to generate, for example, an image rate of 60 Hz. The sawtooth signal has in the frequency range the multiples of the even and odd harmonics of the fundamental frequency. Two possible sawtooth signals with different retrace times are shown in the diagram of FIG. 11 as dashed and continuous curves. The time is shown on the abscissa axis and the amplitude of the sawtooth signal on the ordinate axis. In FIG. 11, the rising edges are the edges that control the MEMS mirror from row to row. The falling flanks represent the return of the MEMS mirror to the starting position. In FIG. 12, the corresponding sawtooth signal is shown in the frequency range.Linear drivers or digital drivers are usually used to drive the MEMS mirrors in the quasistatic state. In order to achieve sufficient accuracy during the control or to increase the linear deflection, the micromirrors are controlled in a closed loop (so-called closed loop). Different controllers can be used here, e.g. adaptive PD controllers, current controller and position controller in feedforward structure, LMS harmonic controller, iterative harmonic coefficient determination and the like. It is common to the controllers used that they require a very high system band width and thus a very high computing power.A control which operates according to the method of "Iterative Harmonic Coefficient Determination" is disclosed in U.S. Pat. No. 7,952,783 B2.A high system bandwidth and a high computing power mean a high area requirement in the drive ICs, for example for analog-to-digital converters, microcontrollers, digital-to-analog converters, driver stages and the like.For example, MEMS mirror and regulator systems typically require a regulator spread of 1 MHz to accurately regulate each image line. Furthermore, some of the known controller concepts require additional state information of the MEMS mirror, which in reality is very difficult to capture or is very difficult to estimate.For controlling a MEMS mirror, modular multi-feedback controllers can also be used, which have a simple design.Such modular multi-feedback controllers are less complex compared to other controller structures and can therefore be implemented very easily, for example in an ASIC or in software, for example as a program in a DSP or microcontroller.The modular multi-feedback controllers for different MEMS mirrors are parameterized accordingly such that they achieve the best possible performance.Documents DE 10 2007 059 977 A1, DE 10 2010 039 017 A1, DE 10 2004 016 196 B4 and DE 69 731 766 T2 describe methods for adapting the parameters of a controller for microelectromechanical actuators, which partially have features of the method for adapting the parameters of a controller for microelectromechanical actuators according to claim 1.Disclosure of the InventionThe present invention discloses a method for adapting the parameters of a controller for micromechanical actuators having the features of patent claim 1 and a device for adapting the parameters of a controller for a micromechanical actuator having the features of patent claim 5.Accordingly, the following is provided:A method for adapting the parameters of a controller for micromechanical actuators, having the steps of applying a test signal to the micromechanical actuator, which test signal has a jump and / or impulse and / or a frequency sweep, detecting a test signal response (e.g. a jump or impulse response) of the micromechanical actuator to the test signal, identifying an absolute position of at least one mode in the detected test signal response, and adapting at least one of the parameters of the controller on the basis of the identified absolute position of the at least one mode.The present invention further discloses:A device for adjusting the parameters of a controller for a micromechanical actuator, having a signal generator which is designed to output a test signal which has a jump and / or pulse and / or a frequency sweep to the micromechanical actuator, having a detection device which is designed to detect a test signal response of the micromechanical actuator to the test signal, having an analysis device which is designed to identify an absolute position of at least one mode in the detected test signal response, and having an adjustment device which is designed to adjust at least one of the parameters of the controller on the basis of the identified absolute position of the at least one mode.Advantages of the InventionThe realization on which the present invention is based consists in the fact that a controller module, for example a modular multi-feedback controller, is adapted to the respective micromechanical actuator to be controlled in order to achieve the best possible performance or to enable the best possible control.The idea on which the present invention is based is now to take this knowledge into account and to provide a possibility for very easily determining the parameters of a controller which is used to control a micromechanical actuator.For this purpose, the present invention provides that a test signal is applied to a micromechanical actuator without a controller connected upstream, said test signal having a signal jump, signal pulse or a frequency sweep.If a test signal according to the invention is applied to such a micromechanical actuator, the latter is deflected and thus generates a measurable test signal response to the test signal.The present invention now provides for this test signal response to be detected and evaluated.In particular, the present invention provides for identifying an absolute position of at least one mode in the detected test signal response and for adapting the at least one parameter of the controller on the basis of this detected absolute position of the at least one mode.The adaptation of the parameters of the respective controller for the respective micromechanical actuator used leads to a very high-quality controller behavior with a high control quality.For example, all technology-related fluctuations between individual micromechanical actuators can be compensated for with the aid of the present invention, and a high robustness of the overall system can be achieved.Advantageous embodiments and refinements emerge from the dependent claims and from the description with reference to the figures.According to the invention, the further step of determining a relative position of the modes with respect to one another in the detected test signal response is provided, wherein, during the adaptation of the at least one parameter, the at least one mode is adapted based on the identified absolute position and / or the relative position of the modes with respect to one another in the detected test signal response. This enables exact adaptation of the parameters to the respective micromechanical actuator.According to the invention, the further step of detecting at least one phase rotation or at least one phase jump in the frequency response of the micromechanical actuator on the basis of the detected test signal response is provided, wherein, during the adaptation of the at least one parameter, the at least one parameter is adapted on the basis of the identified absolute position of the at least one mode and / or the relative position of the modes in the detected test signal response with respect to one another and / or the detected phase rotations or the detected phase jumps. This makes it possible to set the parameters of the respective controller with even higher accuracy.In one embodiment, the further step of determining a damping factor for each of the modes based on the detected test signal response is provided, wherein, during the adaptation of the at least one parameter, the at least one parameter is adapted based on the identified absolute position of the at least one mode and / or the relative position of the modes in the detected test signal response with respect to one another and / or the detected phase rotations or the detected phase jumps and / or the determined damping factors. This makes possible a very simple and precise setting of the parameters of the respective controllers.In one embodiment, the further step of transforming the detected test signal response into the frequency range is provided, wherein the identification of the absolute position of at least one mode and / or the determination of the relative position of the modes with respect to one another and / or the detection of a phase rotation or a phase jump and / or the determination of the attenuation factor for each of the modes is carried out on the basis of the transformed test signal response in the frequency range. This enables a very simple and less complex analysis of the test signal response.In one specific embodiment, the further steps of applying a sample signal to the micromechanical actuator with the controller in a closed control loop, which sample signal has a jump and / or pulse and / or a frequency sweep, detecting the system response to the sample signal, and checking the system stability on the basis of the detected system response are provided. This makes it possible to check the correctness of the adapted parameters and, if appropriate, to re-initiate the adaptation of the parameters.In a further embodiment, the parameters of individual elements of the controllers can be parameterized in such a way that these elements are completely switched off or are switched on or off in a targeted manner. For example, this can be done by appropriate adaptation of the parameters. This makes it possible to adapt the regulator structure to the respective micromechanical actuator.In a further embodiment, in addition to the parameters of the controllers, filters can also be determined or calculated, which filters can serve to filter input signals and output signals of the controllers. Such filters can be, for example, low-pass filters, high-pass filters or band-pass filters.The above embodiments and developments can be combined with one another as desired, if appropriate. Further possible embodiments, developments and implementations of the invention also include combinations of features of the invention described above or below with respect to the exemplary embodiments, which combinations are not explicitly mentioned. In particular, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the present invention.Brief Description of the DrawingsThe present invention is explained in more detail below with reference to the exemplary embodiments indicated in the schematic figures of the drawings. The following are shown: FIG. 1 shows a flow diagram of an embodiment of the method according to the invention; FIG. 2 is a block diagram of an embodiment of the apparatus according to the invention; FIG. 3 shows a flow diagram of a further embodiment of the method according to the invention; FIG. 4 shows a flow diagram of a further embodiment of the method according to the invention; FIG. 5 shows a bode diagram for a micromechanical actuator; FIG. 6 shows a bode diagram for a further micromechanical actuator; FIG. 7 shows a test signal response of a micromechanical actuator in the time domain; FIG. 8 shows the test signal response of FIG. 7 in the frequency range; FIG. 9 is a block diagram of a modular multi-feedback controller; FIG. 10 is a block diagram of another modular multi-feedback controller; FIG. 11 shows possible sawtooth signals for driving a MEMS mirror in the time domain; FIG. 12 shows a possible sawtooth signal for driving a MEMS mirror in the frequency range.In all figures, identical or functionally identical elements and devices have been provided with the same reference numerals, unless otherwise indicated.Embodiments of the InventionFIG. 1 shows a flow diagram of an embodiment of the method according to the invention.In a first step S 1, the method provides for the application of a test signal 5 to micromechanical actuator 3, which test signal has a jump and / or impulse and / or a frequency sweep 6.In a second step S 2, a test signal response 8 of micromechanical actuator 3 to test signal 5 is detected.In a third step S 3, an absolute position 10 of at least one mode 11- 1- 11- 3 in the detected test signal response 8 is detected.Finally, the fourth step S 4 provides for the adaptation of at least one of the parameters 13- 1- 13- nof the controller 2 based on the identified absolute position 10 of the at least one mode 11- 1- 11- 3.The interaction or the relationship of action between controller parameters and parameters of the micromechanical actuator as a controlled system can be derived by a person skilled in the art, for example mathematically or experimentally, in order to achieve the best possible results.FIG. 2 shows a block diagram of an embodiment of the device 1 according to the invention.The device 1 has a signal generator 4 which outputs a test signal 5, which has a jump and / or pulse and / or a frequency sweep 6, to the micromechanical actuator 3.Furthermore, a detection device 7 is provided, which detects a test signal response 8 of micromechanical actuator 3 to test signal 5.The detection device 7 outputs the detected test signal response 8 to an analysis device 9, which identifies an absolute position 10 of at least one mode 11- 1- 11- 3 in the detected test signal response 8.Finally, an adaptation device 12 is provided which adapts at least one of the parameters 13- 1- 13- nof the controller 2 based on the identified absolute position 10 of the at least one mode 11- 1- 11- 3.In a further embodiment, the analysis device 9 can be designed to analyze further variables in the test signal response 8. For example, the analysis device 9 can identify the relative position 14 of the modes 11- 1- 11- 3 with respect to one another in the detected test signal response 8, or identify at least one phase rotation 15- 1 or at least one phase jump 16- 1- 16- 2 in the frequency response of the micromechanical actuator 3 on the basis of the detected test signal response 8.The analysis device 9 can also identify, for example, in each case an attenuation factor 17 for the modes 11- 1- 11- 3 on the basis of the detected test signal response 8.In such embodiments, the adaptation device 12 is capable of adapting the parameters 13- 1- 13- nof the controller 2 on the basis of the variables additionally analyzed from the detected test signal response 8.FIG. 3 shows a flow diagram of a further embodiment of the method according to the invention.The method of FIG. 3 is based on the method of FIG. 1 and has the further steps S 5-S 8, which are arranged between steps S 3 and S 4. Further, steps ST1-ST3 are provided, which are arranged after step S4.Step S 5 provides for determining a relative position 14 of the modes 11- 1- 11- 3 with respect to one another. In step S 6, the detection S 6 of at least one phase rotation 15- 1 or at least one phase jump 16- 1- 16- 2 in the frequency response of micromechanical actuator 3 based on detected test signal response 8 is provided. In step S 7, an attenuation factor 17 is determined for each of the modes 11- 1- 11- 3 based on the detected test signal response 8.Finally, in an eighth step S 8, the detected test signal response 8 is transformed into the frequency range.Furthermore, the adaptation S 4 of the parameters 13- 1- 13- nis carried out on the basis of the identified absolute position 10 of the at least one mode 11- 1- 11- 3 and / or the relative position 14 of the modes 11- 1- 11- 3 in the detected test signal response 8 with respect to one another and / or the detected phase rotations 15- 1 or the detected phase jumps and / or the determined attenuation factors 17.Finally, test steps ST 1- ST 3 are provided, which first provide for the application of a test signal to ST 1 of micromechanical actuator 3 with controller 2 in a closed control loop, which test signal has a jump and / or impulse and / or a frequency sweep 6.Further, in step ST2, the system response to the probe signal is detected, and in step ST3, the system stability is checked based on the detected system response.FIG. 4 shows a flow diagram of a further embodiment of the method according to the invention.In step SI, a system identification mode is started, in which the parameters of the respective controller 2 can be adapted and checked.In a step S 11, a check is made as to whether micromechanical actuator 3 has a malfunction. If so, the system identification mode is terminated. If there is no malfunction, micromechanical actuator 3 is excited in step S 12 with a test signal that has a jump and / or pulse and / or a frequency sweep. Micromechanical actuator 3 is in what is known as open loop mode. That is to say, there is no feedback between micromechanical actuator 3 and the controller.In step S 13, the test signal response 8 of the micromechanical actuator to the test signal is detected. In step S 14, the detected test signal response 8 is transformed into the frequency range. This can be done, for example, by means of an FFT (Fast Fourier Transformation) transformation. Step S 15 provides that the relevant parameters 13- 1- 13- nof the controller 2 are identified. For this purpose, for example, the transfer function or a model of the controller 2 can be present.In step S 16, the controller structure is then determined and, in step S 17, a corresponding controller structure is configured for the respective micromechanical actuator 3. Possible regulator structures are shown, for example, in FIGS. 9 and 10. In step S 18, the parameters 13- 1- 13- nfor the respective controller structure are calculated and in step S 19 the parameters 13- 1- 13- nare updated in the controller 2.In parallel with the determination of the parameters 13- 1- 13- n, in step S 20 a determination of filters takes place, which may possibly be necessary to filter the input and output signals of the controller 2. Such filters can be, for example, high-pass filters, low-pass filters or band-pass filters. In step S 21, the corresponding filters in the regulator are activated or deactivated.Finally, in step S 22, it is provided that micromechanical actuator 3 is placed in a closed loop arrangement with corresponding controller 2, i.e., is operated with controller 2 in a closed control loop.In step S 23, a test signal is now applied to micromechanical actuator 3, and in step S 24, a check is made as to whether the entire system behaves stably or has the desired system characteristic.If the overall system is unstable or does not have the desired system characteristic, the method can be carried out again.If the overall system is stable and has the desired system characteristic, the system identification mode is ended in step S 25.FIG. 5 shows a bode diagram for a micromechanical actuator 3, which may be a micromirror, for example.The Bode diagram has two individual diagrams which are arranged one above the other. The frequency is shown logarithmically on the abscissa axis of the diagrams. On the ordinate axis of the upper diagram, the attenuation in dB of the micromirror 3 at the respective frequency is drawn in. On the axis of ordinates of the lower diagram, the phase of the output signal of the micromirror 3 at the respective frequency is shown.In the upper diagram, the curve profile begins at approximately 0 dB and runs approximately parabolically up to a frequency of approximately 550 Hz, where it has a local maximum 10 or a first resonance mode 11- 1 with an amount of approximately 50 dB. From about 550 Hz to about 700 Hz for short, the attenuation drops to about 0 dB to drop to about -70 dB, approximately with the shape of a downwardly open parabola, to 1.6 kHz, where the antiresonant mode 11- 2 is located, and immediately thereafter to rise steeply to about 40 dB, where the second resonance mode 11- 3 is located. From there, the signal falls rapidly to about -10 dB and then extends linearly to -50 dB at 10 kHz until the end of the diagram.In the lower diagram, the phase runs up to about 500 Hz at 0°, in order then to drop steeply to -180° in the first resonance mode. This is a phase rotation 15-1. In the sequence of antiresonant mode 11- 2 and resonance mode 11- 3 at approximately 1.6 kHz, the phase rises briefly to 0° with a phase jump 16- 1 and falls back to -180° with a second phase jump 16- 2.The diagram of FIG. 5 shows how a resonance mode leads to a phase shift of -180°. It can also be seen that an antiresonant diode in this micromirror generates the opposite phase shift by +180°.FIG. 6 shows a bode diagram for a further micromechanical actuator 3.The Bode diagram also has two individual diagrams which are arranged one above the other. The frequency is again plotted logarithmically on the abscissa axis of the diagrams. On the ordinate axis of the upper diagram, the attenuation in dB of the micromirror 3 at the respective frequency is drawn in. On the axis of ordinates of the lower diagram, the phase of the output signal of the micromirror 3 at the respective frequency is shown.In the upper diagram, the curve profile begins at approximately -5 dB and has a local maximum or a first resonance mode with a magnitude of 8.19 dB at a frequency of 741 Hz. From 741 Hz to just before 2.1 kHz, the attenuation drops to about -30 dB, to drop to -83.8 dB at 2.1 kHz (first antiresonant mode) and to rise to 20.5 dB (second resonance mode) until 2.4 kHz. Between 2.4 kHz and 2.6 kHz, the attenuation falls to approximately -3 dB, in order to increase at 2.6 kHz to 21.9 dB (third resonance mode) and to fall back to 2.87 kHz to -56.3 dB (second antiresonant mode). Immediately after 2.87 kHz, the attenuation rises to about 30 dB and then falls to about -56 dB (third antiresonant mode) again up to about 10.9 kHz, immediately rises to about -53 dB and then extends approximately parabolically up to 28 kHz and -35.8 dB (fifth resonance mode) down to -128 dB by up to 49.2 kHz. From there, the signal rises to about 100 dB and falls to about -140 dB at 1 MHz until the end of the diagram.In the lower diagram, the phase runs up to about 400 Hz at 0° in order then to drop up to 741 Hz to -90° and to drop up to about 1 kHz to -180°. At 2.1 kHz, the phase rises to 0° and at 2.4 kHz, the phase falls to -180°, in order to fall to -360° at 2.6 kHz and to rise again to -180° at 2.87 kHz. At approximately 10.9 kHz, the phase response has a peak up to approximately -100°, runs up to 28 kHz at -180° and falls between 28 kHz and 49.2 kHz at -360°, in order then to run up to the end of the diagram at -180°.The diagram of FIG. 6 clearly shows the phase shift from -180° to -360°, which a micromirror 25 has when two modes are followed by an antiresonant mode in the Bode diagram of micromirror 25.It is clear from FIGS. 5 and 6 that different micromechanical actuators 3, for example micromirrors 3, can have very different behaviors. For example, the micromirror of FIG. 5 has only phases of 0° to -180°, while the micromirror 3 of FIG. 6 has phases of between 0° and -360°.The present invention offers a possibility of compensating these different behaviors of micromirrors 3 by determining the parameters of respective controller 2 on the basis of test signal response 8 of respective micromirror 3. This is explained in more detail in connection with FIG. 8.FIG. 7 shows a test signal response 8 of a micromechanical actuator in the time domain.The abscissa axis of the graph shows the time in seconds from about -0.01s to 0.33s. The axis of ordinates shows a dimensionless raw value of an analog-to-digital converter which records the displacement of micromechanical actuator 3.The signal has oscillations with all frequencies or frequency components of the micromirror and begins to oscillate at 0 s with its maximum amplitude of approximately 6000 about the signal center point of 4000. The amplitude of the signal decreases exponentially and is already only about 4000 at 0.05 s.The recorded test signal response 8 makes analysis very difficult in the time domain, since the characteristic values are difficult to extract. Therefore, this test signal response 8 is transformed into the frequency domain. This is explained in more detail in connection with FIG. 8.FIG. 8 shows the test signal response 8 of FIG. 7 in the frequency range. The attenuation is plotted over time. The frequency ranges from 0 Hz to 5000 Hz. The attenuation ranges from -55 dB to -105 dB.The profile of the damping begins at 0 Hz at approximately -100 dB and rises up to approximately 750 Hz to approximately -57 dB, where the first resonance mode 11- 4 of the corresponding micromechanical actuator 3 is located. From the first resonant mode 11- 4, the signal falls down to -99 dB up to about 2550 Hz, where the first antiresonant mode 11- 5 is located. At approximately 2100 Hz, the second resonant mode 11- 6 is located, where the attenuation increases to -65 dB, in order to thereafter decrease to -97 dB and to increase again to 87 dB until approximately 2900 Hz in the third resonant mode 11- 7. Immediately thereafter, the attenuation in the second antiresonant mode 11-8 falls to -105dB and again rises to -95dB. From there, the attenuation falls flat down to -100 dB until the end of the diagram.The transfer function of the micromechanical actuator is dependent on the respective micromechanical design and its properties and is different. This can be, for example: with: D01 first mode attenuation factor D02 second mode attenuation factor D02b second antiresonant mode attenuation factor f01 first mode frequency f02 second mode frequency f02b third mode frequency ks01 mode 1 portion on the DC gain of transfer function ks02 mode 2 portion on the DC gain of transfer function ks03 mode 3 portion on the DC gain of transfer functionThe interaction or the correlation of action between the controller parameters and the parameters of the micromechanical actuator as a controlled system can be derived by the person skilled in the art, for example mathematically or experimentally, in order to achieve the best possible properties of the closed control loop.FIG. 9 shows a block diagram of a modular multi-feedback controller 1.The regulator 20 has a first signal input 21 which is coupled to a first regulator element 25. The first control element 25 is coupled to a third control element 29, which is coupled to a fourth control element 31.Furthermore, a second signal input 23 is provided, which transmits a received measurement signal 24 to a second regulator element 27 and to the third regulator element 29. The received measurement signal 24 identifies a recorded response of the micromechanical actuator 3 to a control signal 32. the second regulator element 27 is connected downstream of the second signal input 23, which modifies the received measurement signal 24 by minimizing the quality of the first mode 11- 1 of the received measurement signal 24 or attenuating it.The first signal input 21 is designed to receive a reference signal 22 and to transmit it to the first regulator element 25, which filters out or attenuates predefined frequency modes and / or predefined frequency components from the received reference signal 22.The first regulator element 25 of the regulator 20 can be designed as a digital filter unit, e.g. as an IIR filter, a notch filter or an FIR filter, and serves to eliminate, attenuate or suppress undesired frequency modes or frequency components in the reference signal 22 reference variable.The second controller element 27 may minimize the quality of the first mode of the micromechanical actuator 3 in the closed loop with the received measurement signal 24. In one specific embodiment, second filter element 27 may shift the complex pole points of the first mode of micromechanical actuator 3 in the closed control loop in the direction of the real axis of the pole zero point diagram by processing measurement signal 24. This corresponds to an increase in the attenuation of the mode. Furthermore, the second regulator element 27 can eliminate the pole point of the first mode of the measurement signal 24 and insert a new pole point with a changed attenuation factor, e.g. of 0.707.In one embodiment, the Q factor of the second or higher modes can be minimized by further feeding back one or more frequency information items.In one embodiment, the attenuation factor of the second or higher modes can be increased by further feeding back one or more frequency information items.The third regulator element 29 is the actual core of the regulator 20 and minimizes the control deviation between the filtered and / or attenuated reference signal 26 and the received measurement signal 24.The third controller element 29 may be a PID controller, for example.The fourth controller element 31 rotates the phase of the difference of the minimized reference signal 30 and the modified measurement signal 28 for at least a predetermined frequency or for a predetermined frequency range. The rotated measurement signal is transmitted as the control signal 32 to the micromechanical actuator 3.The fourth regulator element 31 is used, for example, for phase inversion or phase rotation if the transfer function of the micromechanical actuator used has two successive resonance modes, which are followed by an antiresonant mode.FIG. 10 shows a block diagram of another modular multi-feedback controller 40.The regulator 40 has a first signal input 41 which is coupled to a first regulator element 45. The first control element 45 is coupled to a third control element 49.Furthermore, a second signal input 43 is provided, which transmits a received measurement signal 44 to a second regulator element 47, to a fourth regulator element 51 and to the third regulator element 49. Received measurement signal 44 identifies a recorded response of micromechanical actuator 3 to a control signal 52. second controller element 47 and fourth controller element 51 are connected downstream of second signal input 43, which modify received measurement signal 44. The second regulator element 47 minimizes or attenuates the quality of the first mode of the received measurement signal 44.The first signal input 41 is designed to receive a reference signal 42 and to transmit it to the first regulator element 45, which filters out or attenuates predefined frequency modes and / or predefined frequency components from the received reference signal 42 and outputs the filtered and / or attenuated reference signal 46.The first regulator element 45 of the regulator 40 can be designed as a digital filter unit, e.g. as an IIR filter, a notch filter or an FIR filter, and serves to eliminate, attenuate or suppress undesired frequency modes or frequency components in the reference signal 42 reference variable.The second controller element 47 may minimize the quality of the first mode of the micromechanical actuator 3 in the closed loop by processing the received measurement signal 44. In one specific embodiment, second filter element 47 may shift the complex pole points of the first mode of micromechanical actuator 3 in the direction of the real axis of the pole zero point diagram of the closed control loop by processing measurement signal 44. This corresponds to an increase in the attenuation of the mode. Furthermore, the second controller element 47 can eliminate the pole point of the first mode of the micromechanical actuator 3 by processing the measurement signal 44 and insert a new pole point with a changed damping factor, e.g., of 0.707, in the closed loop.In one specific embodiment, the quality factor of the second or higher modes of micromechanical actuator 3 may be minimized by further feedback of one or more frequency information items.In one embodiment, the attenuation factor of the second or higher modes of the MEMS element can be increased by further feedback of one or more frequency information items.The second regulator element 47 has a transfer function of at least 1st order and can have both an even and an odd order.The third regulator element 49 is the actual core of the regulator 40 and minimizes the control deviation between the filtered and / or attenuated reference signal 46 and the received measurement signal 44. Before the control signal 52 is transmitted to the micromechanical actuator 3, the modified measurement signal 48 and the received measurement signal 44 are also subtracted from the latter.The third controller element 10 may be a PID controller, for example.The fourth controller element 51 is used to adapt the bandwidth of the micromechanical actuator 3 in the closed loop by processing the received measurement signal 44 and thus the overall system comprising micromechanical actuator 3 and controller 40. For example, the bandwidth of the overall system can be increased or decreased

Claims

Method for adapting the parameters (13-1-13-n) of a controller (2) for micromechanical actuators (3), having the steps: applying (S1) a test signal (5) to the micromechanical actuator (3) which has a jump and / or pulse and / or a frequency sweep (6); detecting (S2) a test signal response (8) of the micromechanical actuator (3) to the test signal (5); identifying (S3) an absolute position (10) of at least one mode (11-1-11-3) in the detected test signal response (8); and adapting (S4) at least one of the parameters (13-1-13-n) of the controller (2) on the basis of the identified absolute position (10) of the at least one mode (11-1-11-3); and having the further step: determining (S5) a relative position (14) of the modes (11-1-11-3) with respect to one another in the detected test signal response (8); and having the further step: detecting (S6) at least one phase rotation (15-1) or at least one phase jump (16-1-16-2) in the frequency response of the micromechanical actuator (3) on the basis of the detected test signal response (8); wherein, during the adaptation (S4), the at least one parameter (13-1-13-n) is adapted on the basis of the identified absolute position (10) of the at least one mode (11-1-11-3) and the relative position (14) of the modes (11-1-11-3) in the detected test signal response (8) with respect to one another and the detected phase rotations (15-1) or the detected phase jumps.Method according to Claim 1, having the further step: determining (S7) in each case one attenuation factor (17) for each of the modes (11-1-11-3) on the basis of the detected test signal response (8); wherein, during the adaptation (S4), the at least one parameter (13-1-13-n) is adapted on the basis of the identified absolute position (10) of the at least one mode (11-1-11-3) and / or the relative position (14) of the modes (11-1-11-3) in the detected test signal response (8) with respect to one another and / or the detected phase rotations (15-1) or the detected phase jumps and / or the determined attenuation factors (17).Method according to one of Claims 1 to 2, having the further step: transformation (S8) of the detected test signal response (8) into the frequency range; wherein the identification (S3) of the absolute position (10) of at least one mode (11-1 - 11-3) and / or the determination (S5) of the relative position (14) of the modes (11-1 - 11-3) with respect to one another and / or the detection (S6) of a phase rotation (15-1) or a phase jump (16-1 - 16-2) and / or the determination (S7) of the attenuation factor (17) is carried out for each of the modes (11-1 - 11-3) on the basis of the transformed test signal response (8) in the frequency range.Method according to one of Claims 1 to 3, having the further steps: applying a test signal which has a jump (6) to the controller (2) to (ST1) the micromechanical actuator (3) in a closed control loop by the controller (2); detecting (ST2) the system response to the test signal; and checking (ST3) the system stability on the basis of the detected system response.Device (1) for adapting the parameters (13-1-13-n) of a controller (2) for a micromechanical actuator (3): having a signal generator (4) which is designed to output a test signal (5) which has a jump and / or pulse and / or a frequency sweep (6) to the micromechanical actuator (3); having a detection device (7) which is designed to detect a test signal response (8) of the micromechanical actuator (3) to the test signal (5); having an analysis device (9) which is designed to identify an absolute position (10) of at least one mode (11-1-11-3) in the detected test signal response (8); and having an adaptation device (12) which is designed to adapt at least one of the parameters (13-1-13-n) of the controller (2) on the basis of the identified absolute position (10) of the at least one mode (11-1-11-3), wherein the analysis device (9) is furthermore designed to identify the relative position (14) of the modes (11-1-11-3) with respect to one another in the detected test signal response (8); and wherein the analysis device (9) is furthermore designed to identify at least one phase rotation (15-1) or at least one phase jump (16-1-16-2) in the frequency response of the micromechanical actuator (3) on the basis of the detected test signal response (8); and the adaptation device (12) is designed to adapt the at least one parameter (13-1-13-n) of the controller (2) on the basis of the absolute position (10) of the at least one mode (11-1-11-3) and the relative position (14) of the modes (11-1-11-3) to one another in the detected test signal response (8) and the identified phase rotations (15-1) or the identified phase jumps.The apparatus according to claim 5, wherein the analysis device (9) is further configured to identify a damping factor (17) for the modes (11-1-11-3) based on the detected test signal response (8) in each case; and the adaptation device (12) is configured to adapt the at least one parameter (13-1-13-n) of the controller (2) based on the absolute position (10) of the at least one mode (11-1-11-3) and / or the relative position (14) of the modes (11-1-11-3) to one another in the detected test signal response (8) and / or the identified phase rotations (15-1) or the identified phase jumps and / or the damping factors (17).Device according to one of Claims 5 to 6, wherein the signal generator (4) is furthermore designed to apply a sample signal, which has a jump and / or pulse and / or a frequency sweep (6), to the micromechanical actuator (3) with the regulator (2) in a closed control loop; wherein the detection device (7) is furthermore designed to detect the system response of the micromechanical actuator (3) with the regulator (2) in the closed control loop; and wherein the analysis device (9) is furthermore designed to determine the system stability on the basis of the system response.

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