Method for preventing vibration excitation of a machine element movable by a drive

Abstract

Method for preventing the excitation of vibration in a machine element movable by a drive, which is moved by means of a speed control regulated by a control device, wherein the control device is supplied with setpoint values, wherein at least one setpoint value is filtered by a blocking filter and the blocking filter is set on the basis of a natural frequency of the machine element, wherein at least one machine element has damping properties and an additional damper, in particular a mass-spring damper, is used, wherein a transfer function of the blocking filter consists of a blocking depth (a) and a central angular frequency (ω) c ) is calculated, where the blocking depth (a) is determined by the damping of the absorber (D Z ) according to a = 2D z is calculated and the central angular frequency (ω) c ) the frequency of the damper (ω Z ) corresponds.

Description

[0001] The present invention relates to a method for preventing the excitation of vibration in a machine element that can be moved by a drive. State of the art

[0002] Dynamic systems excited near their natural frequencies exhibit amplified vibrations in their system response. If such a system, for example a part of a rotating machine, is excited across a broad frequency spectrum, there is a risk of resonance phenomena occurring under unfavorable operating conditions.

[0003] Every vibrating mechanical system (e.g., an axis of a machine tool) is generally characterized by at least one natural frequency, which can be excited during a movement process and is noticeable in the actual position.

[0004] Resonant vibrations in mechanical systems often lead to a limitation of the maximum possible (excitation) dynamics, as well as performance and positioning accuracy. In certain cases, mechanical wear can also result from resonant excitation of a system.

[0005] For this reason, efforts are made to avoid any corresponding stimulation of the mechanics.

[0006] The devices affected by the aforementioned problems include, among others, devices for positioning read / write heads of floppy disk drives and hard disk drives, positioning systems present in large room structures, machine tools, printing presses, packaging machines, robots, coordinate measuring machines, container cranes and the like.

[0007] It is known that to prevent vibration of moving parts, the corresponding system can be stiffened and / or the load reduced. However, for cost reasons and due to physical limitations, especially when additional design requirements exist, an arbitrary change in stiffness is not always possible. Reducing the load may lead to a decrease in the system's performance.

[0008] It is also known that corresponding oscillations can be dampened by active control loops such as cascade or state controllers. However, such control is often not time-optimal.

[0009] Furthermore, methods for jerk limitation are known for the speed control of numerical controls, e.g., for machine tools or robots. Jerk limitation aims to reduce the load on the individual axes of a machine without excessively increasing program processing time.

[0010] With jerk limiting, it is possible to delay the acceleration build-up for a movement operation so that the setpoint is smoothed and the mechanism is moved with minimal vibration excitation. However, higher-frequency acceleration and deceleration processes pose problems, as they must be performed with lower dynamics to avoid excessive excitation of the oscillating mechanism. These lower dynamic values ​​often undesirably increase the path speed and thus the program execution time. In particular, classic jerk filters (corresponding to a first-order lag controller or filters using moving averages) have proven to be only conditionally suitable in practice, especially at low resonant frequencies.

[0011] From DE 102 00 680 B4, a further development of a corresponding control method for jerk reduction is known in this context, in which an adapted setpoint generation is achieved by means of a modified or extended interpolator. The profiles of the provided setpoints are specifically adapted to the respective structure by the extended interpolator by modifying (rounding) them in such a way that they no longer exhibit any interfering frequency components. By selectively influencing the setpoint generation in the interpolator, which is adapted and assigned to the respective mechanics, an acceleration of corresponding jerk-reducing processes can be achieved.

[0012] Document US 2002 / 0016648 A1 describes a numerical control unit with a speed feedback control system and a method for using a numerical control unit. In the method, a motor is controlled via a speed guide, incorporating a band elimination filter that is adjusted taking into account a peak frequency.

[0013] Document US 5,960,969 A describes a method for damping the vibration of a load suspended from a crane cable. A damping filter is used in the motor control.

[0014] Document US 3,411,093 A describes a frequency tracking circuit based on the gain-phase properties of a feedback servo system. This allows a specific frequency component to be tracked from a plurality of frequencies. However, such methods suffer from either reduced system performance, as certain acceleration and deceleration processes must be performed with lower dynamics, or a lack of flexibility, as a specific setpoint must be generated for a particular mechanical device.

[0015] The invention is therefore based on the objective of providing improved measures to prevent the excitation of vibration in a machine element that can be moved by a drive and is moved by means of a speed control device.

[0016] This problem is solved by a method with the features of claim 1 for preventing vibration excitation. Advantageous embodiments are the subject of the dependent claims and the following description. Advantages of the invention

[0017] An inventive method for preventing vibration excitation of a machine element movable by a drive, which is moved by means of a speed control regulated by a control device, wherein the control device is supplied with setpoint values, is carried out by filtering at least one setpoint value through a blocking filter or a bandstop filter and adjusting the blocking filter or the bandstop filter on the basis of a natural frequency of the machine element.

[0018] By using a suitable blocking filter according to the invention, which conditions the input signal, it is possible to eliminate critical resonance frequencies from the setpoint curve and thus prevent excitation of the corresponding mechanical system. The method according to the invention allows for the avoidance or suppression of machine resonances through an adapted setpoint curve. Based on a correspondingly improved method, contour accuracy and positioning time (productivity) can also be optimized. This results in significant advantages over the prior art.Instead of a filtering effect achieved solely on the basis of a rounding of a jerk function and (fixed) adjusted jerk values ​​of a correspondingly prepared jerk profile, according to the invention the corresponding target value curve itself is filtered on the basis of an existing machine parameter.

[0019] It should be emphasized that the measures of the present invention act on an already existing setpoint, and the setpoint influence by the blocking filter is subordinate to the setpoint generation process. This allows a setpoint or setpoint profile to be provided jointly for several movable machine elements, and only the processing of the setpoints then needs to be carried out individually and technically easily for the movable machine elements. In contrast to the prior art, such as the control method disclosed in DE 102 00 680 B4, individual, separate setpoint generation devices are therefore not required. This results in significant improvements in both economic and design terms.

[0020] According to a preferred embodiment, the setpoint is provided by an interpolator and / or the filtering of at least one setpoint is performed downstream of the setpoint provision. A corresponding interpolator can provide common or uniform setpoints for certain devices, after which individualized setpoint processing can then be carried out in the individual devices.

[0021] A method according to the invention can advantageously be implemented in the drive of a movable machine element, i.e., integrated into the drive and independent of the higher-level control system. It is particularly preferred that the corresponding drive itself includes a control unit in which the method according to the invention is implemented. This enables autonomous control of the corresponding drive unit, which can operate independently of other variables and / or signals and therefore autonomously within the unit. In contrast to the prior art, it is not necessary to provide a separate, individualized setpoint for each drive; instead, a basic setpoint is automatically generated within the unit.

[0022] According to a particularly preferred embodiment of the method according to the invention, a blocking filter with a center frequency and a bandwidth is used, and the center frequency and / or the bandwidth of the blocking filter are determined and / or adjusted based on a natural frequency of the machine element. Advantageously, such adjustment is made directly based on device parameters, thereby achieving an optimally adapted filtering effect.

[0023] Problems arise when setting up conventional notch filters. Normally, a notch filter with a center frequency is tuned to a resonant frequency, and a suitable bandwidth is selected. However, since the effective resonant frequency shifts during operation depending on the controller parameters, a corresponding center frequency cannot be reliably (fixed). The bandwidth of such a filter also requires optimization to achieve the best possible filter performance. According to the invention, a particularly advantageous controller parameterization can be achieved by determining and / or adjusting both the center frequency and the bandwidth, especially in the form of a cascading controller structure.

[0024] According to the invention, a transfer function of the blocking filter is provided for, consisting of a blocking depth a and the central angular frequency ω. cA bandwidth coefficient Q is calculated. This is particularly advantageous. Controller parameters can therefore be derived directly from existing system parameters.

[0025] At least one machine element exhibits damping properties, and / or an additional damper, in particular a mass-spring damper, is used. The method according to the invention is therefore equally suitable for corresponding devices with and without additional dampers. It should be understood that the corresponding damper frequency corresponds to the excitation frequency of the corresponding mechanical component.

[0026] An advantageous further development provides that the denominator function of a corresponding transfer function N filter (s) is calculated according to the following equation: Nfilter(s)=1ωc2s2+aωcs+11ωc2s2+1Qωcs+1.

[0027] According to the invention, the blocking depth a is derived from the damping of a damper D.Z according to a = 2D z calculated. The central angular frequency ω c According to the invention, this corresponds to the frequency ω of a damper. Z Advantageously, the bandwidth coefficient is taken from the range of 1 / 2 to 2 / 2 selected. By setting or calculating the corresponding values, filter parameterization can be carried out quickly in each case.

[0028] According to a preferred further training, the damping of the damper D Z and / or the frequency of the damper ω Z This is determined by a measurement, in particular a frequency response measurement. These common measurement methods allow for the straightforward determination of current and / or machine-adapted input variables.

[0029] The method according to the invention can be used particularly advantageously in devices in which the movable machine element is part of a device for positioning a read / write head of a floppy disk drive or a hard disk drive, part of a positioning system, a machine tool, a printing press, a packaging machine, a robot, a coordinate measuring machine, and / or a container crane. The method according to the invention can advantageously be used in all such devices in which movable, i.e., rotatable and / or positionable, elements are used.

[0030] According to a particularly preferred embodiment, for which separate patent protection is sought, at least one setpoint is filtered by a vibration filter. Particularly in the context of its use in the control of electric servo drives, this offers significant advantages, especially in addition to simplified positioning. Interpolating operation can also be implemented. It has been shown that both the aforementioned blocking filter and a vibration filter are equally suitable for this method, and a combination of both methods can also be used. It is understood that all the aforementioned control tasks can also be performed with the additional use of a suitable vibration filter.

[0031] The (exclusive or additional) use of a vibration filter is particularly intended in positioning systems, machine tools, printing presses, packaging machines, robots, coordinate measuring machines, and / or container cranes or their drives and / or controls.

[0032] The vibration filter is expediently designed according to the equation F(s)=A1+A2e−sT regulated, whereby the following applies: A1=11+e−πDz / 1−Dz2, A2=e−πDz / 1−Dz21+e−πDz / 1−Dz2 and T=TZ2 where F(s) is the Laplace transform of the time function, A1 and A2 are the defined step heights (amplitudes) of a step signal generated at the output by a constant input signal in the form of a unit step e(t), T is the defined spacing between the steps of the step signal, and Tz is the damping time corresponding to the damper frequency. The vibration filter can also be directly determined based on machine parameters, namely the mechanical damping of the system D. Z and the damper frequency or damper time of the mechanics T Z be parameterized.

[0033] A computing unit is advantageously, particularly in terms of programming, equipped to carry out a method according to the invention using a corresponding machine with movable elements.

[0034] Advantageously, the method according to the invention can be integrated into a drive control unit, particularly a drive of an automation device. This enables, for example, axis-specific, independent, and automatic control, whereby, for instance in the case of interpolating servo axes, contour accuracy is advantageously increased by vibration avoidance. In particular, such a drive control unit can be used in devices such as positioning systems, machine tools, printing presses, packaging machines, robots, coordinate measuring machines, and / or container cranes.

[0035] In addition to the described method, i.e., in addition to the setpoint preparation, superimposed active vibration damping can also be advantageously implemented. This can be particularly beneficial if the setpoint preparation is impaired or its effectiveness reduced due to the influence of disturbing forces. This allows for a reduction of vibration on the load side at the so-called TCP (Tool Center Point, i.e., the point where the tool contacts the workpiece), even in the case of vibration excitation from the respective process (in addition to the excitation described above due to the control system), such as from one or more adjacent axes.

[0036] A computer program product with program code stored on a computer-readable data carrier is configured to perform all steps according to a method according to the invention when the computer program is executed on a computer or a corresponding computing unit, in particular a computing unit in a drive control device. Suitable data carriers include, in particular, floppy disks, hard disks, flash memory, EEPROMs, CD-ROMs, DVDs, etc. Downloading a program via computer networks (Internet, intranet, etc.) is also possible.

[0037] Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawing.

[0038] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention.

[0039] The invention, along with its associated theoretical background and problem statement, is schematically illustrated in the drawing using exemplary embodiments and is described in detail below with reference to the drawing. Character description Fig. Figure 1 shows a model for deriving the fundamentals of the method according to the invention. Fig. Figure 2 shows a root locus curve of a speed control loop and illustrates the “missing zero effect” according to the state of the art. Fig. Figure 3A shows a transfer function of the motor of a motor speed control loop according to the state of the art in the form of a pole-zero diagram. Fig. Figure 3B shows a transfer function of the load of a motor speed control loop according to the state of the art in the form of a pole-zero diagram. Fig. Figure 4A shows a Bode diagram of a transfer function of the motor of a motor speed control loop according to the state of the art. Fig. Figure 4B shows a Bode diagram of a load transfer function of a motor speed control loop according to the state of the art. Fig. Figure 5 shows step responses of the motor and the load in a speed control loop according to the state of the art. Fig. Figure 6 shows a Bode diagram of transfer functions of the motor and the load of a position control loop according to the state of the art. Fig. Figure 7 shows step responses of the motor and the load in a position control loop according to the state of the art. Fig. Figure 8 shows a diagram illustrating the selection of the bandwidth coefficient Q according to a particularly preferred embodiment of the invention. Fig. Figure 9A shows a Bode diagram of a transfer function of the motor of a position control loop using a blocking filter according to a particularly preferred embodiment of the invention. Fig. Figure 9B shows a Bode diagram of a load transfer function of a position control loop using a blocking filter according to a particularly preferred embodiment of the invention. Fig. Figure 10 shows step responses of the motor and the load of a position control loop using a blocking filter according to a particularly preferred embodiment of the invention. Fig. Figure 11 shows a diagram to illustrate the parameters for adjusting a vibration filter according to a particularly preferred embodiment of the invention. Fig. Figure 12 shows a Bode diagram of a vibration filter according to a particularly preferred embodiment of the invention. Fig. Figure 13 shows step responses of the motor and the load of a position control loop using a vibration filter according to a particularly preferred embodiment of the invention. Fig. Figure 14 shows a scheme of a control system that operates using a particularly preferred embodiment of the method according to the invention.

[0040] The theoretical background of the invention and the problem statement are explained below with reference to the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 to Fig. 7 described.

[0041] Fig. Figure 1 shows a model for deriving the fundamentals of the solution according to the invention. Fig. Figure 1 represents a second-order system, denoted by 1. System 1 is a two-mass oscillator comprising two elements or masses 2 and 3, each with a mass inertia J1 and J2, respectively. Masses 2 and 3 are rotated by torques M1 and M2, respectively, and exhibit angles φ1 and φ2. An (elastic) interaction exists between elements 2 and 3 with a stiffness c. 12 and a damping d 12 .

[0042] The transfer function from torque M1 to rotational speed φ̇1 ̇1 (corresponding to dφ1 / dt) is given in equation 1 below: GM1ω1=φ˙1(s)M1(s)=1s(J1+J2)⋅1+s⋅d12c12+s2⋅J2c121+s⋅d12c12+s2⋅J1⋅J2c12⋅(J1+J2).

[0043] The first term of the transfer function in equation 1 gives the integral relationship between the rotational speed and the driving torque M1, whereas the second term describes the influence of the elastic coupling. The transfer function of this second term can be transformed into the following equation 2: Fsys(s)=1ωZ2s2+2Dzωzs+11ωn2s2+2Dωns+1, with ωZ=c12J2;DZ=d1221c12J2 and ωn=c12J1+J2J1J2;DZ=d1221c12J1+J2J1J2.

[0044] In equations 2, 3 and 4, F denotes sys (s) the Laplace transform of the time function, ω Z the damper frequency (regulated natural frequency 2nf), ω n the frequency of the mechanics (unregulated natural frequency), D Z the damping of the damper and D the relative damping.

[0045] The decisive factor for describing the quality of such a system is not the response of the motor, but that of the load. Therefore, in addition to the above, the transfer function from torque to load must also be considered. GM1ω2=φ˙2(s)M1(s)=1s(J1+J2)⋅1+s⋅d12c121+s⋅d12c12+s 2⋅J1⋅J2c12⋅(J1+J2)=1s(J1+J2)⋅2Dωns+11ωn2s2+2Dωns+1.

[0046] The last term of equation 5 shows that the load transfer function has no conjugate zero. This lack of a zero, or "missing zero," is referred to as the "missing zero effect" in the following.

[0047] The missing zero effect is in Fig. Figure 2 illustrates this. The figure represents a root locus of an open-loop speed control system, where R denotes the real axis and I the imaginary axis. The poles ω nThe frequency of the mechanics depends on the height of the frequency range. According to the integration of torque to velocity and the control by a PI controller, the two poles lie at the coordinates (0, 0) and move towards the zero w. Z .

[0048] After adjusting a suitable PI controller and the position of the poles of the motor speed control loop, a transfer function is obtained according to the pole-zero diagrams, which are shown in the Fig. 3A and Fig. 3B are shown, where Fig. 3A the transfer function of the motor and Fig. 3B shows the load.

[0049] In the Fig. 4A and Fig. Figure 4B shows the corresponding Bode plots. Figure 41 denotes the graph for an open-loop speed control system, and Figure 42 the graph for a closed-loop speed control system. In these and the following Bode plots, F denotes the frequency (in Hz), P the phase (in degrees), and M the magnitude (in dB). Each pair of poles of the motor's transfer function is represented by... Fig. 3A are located in the higher frequency range, with two further poles near the zero. The effect of these poles is described as follows: Fig. 4A can be seen, in the case of the motor, essentially compensated by the zero point. In the transfer function of the load of Fig. 3B, however, lacks a zero point, while the other poles essentially have the same position. The resulting lack of compensation in the low-frequency range creates a vibration problem under load.

[0050] Fig. Figure 5 shows the step responses of the motor 51 and the load 52 in a closed-loop speed control system. As can be seen, the motor does exhibit oscillations, but these are much smaller than those of the load. The axes of this and the following step response diagrams are labeled T (time in seconds) and A (amplitude).

[0051] The Fig. Figure 6 shows the transfer behavior of the motor 61 and the load 62 of closed position control loops in the form of the corresponding Bode plots. While the Bode plot of the motor ( Fig. 3A) reveals no significant problems regarding the load ( Fig. 3B) to detect a significant vibration excitation attributable to the reasons stated above.

[0052] Fig. Figure 7 shows the step responses of the motor 71 and the load 72 in a closed position control loop. As can be seen, the motor exhibits no vibrations, while the load shows significant vibrations. Therefore, the load is not accepted in this case; that is, it is not moved directly, but only under significant vibration excitation.

[0053] The solution according to the invention, using a blocking filter, is now described with reference to the Fig. 8, Fig. 9 to Fig. 10 described.

[0054] As explained previously, the poles located in the low frequency range of the Fig. 3A and Fig. 4A does not present any significant problems regarding the motor's response, because a zero point is located next to each of these poles. However, due to the missing zero effect, a strong vibration excitation with respect to the load is observed ( Fig. 3B and Fig. 4B). To prevent this excitation, i.e. to avoid these poles without zero compensation, it is advantageous to use a suitable blocking filter.

[0055] The transfer function of a notch filter can be determined using the stopband depth a and the central angular frequency ω. c and a corresponding bandwidth coefficient Q, where Q = ω c / ω b and ω b The bandwidth of the bandpass filter is specified. The denominator of the transfer function is given by Nfilter(s)=1ωc2s2+aωcs+11ωc2s2+1Qωcs+1.

[0056] To reach the poles of Fig. To fully compensate for 4B, the zero of equation 6 must have the same position as the corresponding pole of the Fig. 4B. The pole of the Fig. 3A and Fig. 4A approaches the zero of equation 2. Therefore, to find the poles of the Fig. to eliminate the zero of equation 6 being equal to the zero of equation 2: 1ωc2s2+aωcs+1=1ωZ2s2+2DZωZs+1.

[0057] Equation 6 yields ωc=ωZ and a=2DZ.

[0058] The parameters ω c and a can therefore be determined from the damper frequency ω Z and the damping D Z of the damper. The damper frequency can be easily determined by a frequency response measurement of the corresponding system and used for filtering according to the invention.

[0059] The parameter Q, required in addition to the calculation of the transfer function of the notch filter according to equation 6, defines the pole of the notch filter. This must be chosen carefully. If Q is too large, and thus the bandwidth of the filter F is too high, the filter will be too narrow. bIf Q is too small, the bandpass filter results in an amplitude at the zero point that is too small (i.e., aQ). Conversely, if Q is chosen too small, and thus the bandwidth F is too small, the bandpass filter will result in an amplitude that is too small. b If the bandwidth coefficient is excessively large, the bandwidth of the control loop is reduced. Since the bandwidth coefficient also influences the relative attenuation of the notch filter via the relationship Q = 1 / 2D, Q must be chosen such that the relative attenuation of the pole between 2 and 1. If the blocking filter is set to a position setpoint, for example, the relative damping can assume the value 1. In this case, Q = 1 / 2. If the blocking filter is in the speed control loop, however, the relative damping can be the value 22 accept and it applies Q=22. Thus, the coefficient Q in the range Q=12~22 selected.

[0060] The relevant criteria are in Fig. 8 illustrates this. Fig. 8 are the zeros of the blocking filter 81, the poles 82 of the blocking filter for 22≤Q, the pole 83 of the blocking filter for 1 / 2≤Q≤22, The poles 84 for Q ≤ 1 / 2, the poles 85 of the mechanics and the zeros 86 of the mechanics are shown.

[0061] Fig. Figure 9 shows the Bode diagrams of closed position control loops of the motor ( Fig. 9A) and the load ( Fig. 9B). Here, 91 denotes a graph without the use of a blocking filter 90 according to the invention, and 92 denotes a graph using the blocking filter 90, where Q = 1 / 2 and ω c = ω Z As from Fig. As can be seen in 9B, the load no longer has a pole in the low frequency range when a suitable filter is used.

[0062] Fig. Figure 10 shows this using a corresponding filter with the parameters of the Fig. 9. Determined diagram of the step response of motor 101 and load 102. In particular, in comparison to the unfiltered state of the Fig. 7. The elimination of corresponding vibrations can be observed when using a method according to the invention.

[0063] The use of an (anti-)vibration filter is now discussed with reference to the Fig. 11, Fig. 12 to Fig. 13 described.

[0064] In Fig. Figure 11 shows how, with a constant input signal in the form of a unit step e(t), a step signal with a defined step height (A1, A2) and a defined interval T is generated at the output.

[0065] A corresponding vibration filter has a function according to equation 9 below: F(s)=A1+A2e−sT, with A1=11+e−πDZ / 1−DZ2, A2=e−πDZ / 1−DZ21+e−πDZ / 1−DZ2, and T=TZ2. where F(s) is the Laplace transform of the time function, A1 and A2 are the defined step heights of the in Fig. 11 shown step signal, T the defined distance between the steps of this step signal, and T Z The damping time corresponding to the damper frequency is denoted. As can be seen from equations 10 and 11, the vibration filter can also be directly determined based on machine parameters, namely the mechanical damping of the system D. Z and the damper frequency or damper time of the mechanics T Z be parameterized.

[0066] Fig. Figure 12 shows the Bode plot for the vibration filter, where 121, 122, 123, etc., denote a first, a second, and further dampers. The first damper, 121, in the frequency response of the vibration filter is intended to absorb the mechanical resonance point present in controlled operation (corresponding to the poles in Fig. 3B) eliminate. The first damper of the vibration filter is therefore located at the frequency ω.Z . Further dampers in the frequency response are located at (2n + 1) ω Z , with n = 1, 2, ...

[0067] In Fig. Figure 13 shows the step response of a closed-loop position control system using a vibration filter for the motor 131 and the load 132. It can be observed that a suitable vibration filter can be used very effectively for reducing or eliminating vibration excitation. The reduction is approximately the same as in the context of the Fig. 10 was shown for the blocking filter instead.

[0068] In Fig. Figure 14 shows a schematic of a control system that operates using the method according to the invention. The control system, designated overall by 10, is supplied with an input signal via line of action 20, which in particular represents a setpoint speed.

[0069] The setpoint is essentially processed in units 11 and 12. Unit 11 has a blocking filter 13 and / or a vibration filter 14. The filtered setpoint signal, i.e., processed in the form of an adapted setpoint signal, is provided to unit 17 via the operating line 21.

[0070] Unit 17 may, in particular, include an interpolation device or an interpolator. The interpolated, processed setpoints are then forwarded via line 22 to a further device 12 for setpoint processing. Device 12 may, in particular, include classic jerk filters 15 and / or mean-value jerk filters.

[0071] The signals, further processed in unit 12, are now provided to a position control element 18, which in turn acts on the mechanical control system 19 via control line 24. The mechanical unit or control system 19 provides actual values ​​to the setpoint processing units 11 and 12 via control lines 25 and 26.

[0072] It is understood that the figures shown are only exemplary embodiments of the invention. Any other embodiment is conceivable without departing from the scope of this invention.

Claims

[1] Method for preventing vibration excitation of a machine element movable by a drive, which is moved by means of a speed control controlled by a control device, wherein the control device is supplied with setpoint values, wherein at least one setpoint value is filtered by a blocking filter and the blocking filter is set on the basis of a natural frequency of the machine element, wherein at least one machine element has damping properties and an additional damper, in particular a mass-spring damper, is used, wherein a transfer function of the blocking filter consists of a blocking depth (a) and a central angular frequency (ω) c ) is calculated, where the blocking depth (a) is determined by the damping of the absorber (D Z ) according to a = 2D z is calculated and the central angular frequency (ω) c ) the frequency of the damper (ω Z ) corresponds. [2] Method according to claim 1, characterized by that the setpoint is provided by an interpolator and / or that the filtering of at least one setpoint is downstream of the provision of the setpoint. [3] Method according to claim 1 or 2, characterized by that the process is carried out in a drive of a movable machine element. [4] Method according to any of the preceding claims, characterized by , that a blocking filter with a center frequency and a bandwidth is used and the center frequency and / or the bandwidth of the blocking filter is determined and / or set based on a natural frequency of the machine element. [5] Method according to any of the foregoing claims, characterized by , that a transfer function of the stop filter is derived from the stop depth (a), the central angular frequency (ω) c ) and a bandwidth coefficient (Q). [6] Method according to claim 5, characterized by, that the denominator function of the transfer function N filter (s) is calculated according to the following equation: Nfilter(s)=1ωc2s2+aωcs+11ωc2s2+1Qωcs+1. [7] Method according to claim 5, characterized by , that the bandwidth coefficient is in the range of 1 / 2 to 2 / 2 is selected. [8] Method according to claim 1, characterized by , that the damping of the damper (D Z ) and / or the frequency of the damper (ω Z ) is determined by a measurement, in particular a frequency response measurement. [9] Method according to any of the foregoing claims, characterized by that the movable machine element is part of a device for positioning a read / write head of a floppy disk drive or hard disk drive, part of a positioning system, a machine tool, a printing press, a packaging machine, a robot, a coordinate measuring machine and / or a container crane. [10] Method according to any of the preceding claims, characterized by that at least one setpoint is filtered by a vibration filter. [11] Method according to any of the preceding claims, wherein the vibration filter according to the equation F(s)=A1+A2e−sT is regulated, whereby the following applies: A1=11+e−πDZ / 1−DZ2, A2=e−πDZ / 1−DZ21+e−πDZ / 1−DZ2 and T=TZ2 where F(s) is the Laplace transform of the time function, A1 and A2 are the defined step heights of a step signal generated at the output by a constant input signal in the form of a unit step e(t), T is the defined spacing of the steps of the step signal, and T Z the damping time corresponding to the damper frequency. [12] Method according to one of the preceding claims, in which active vibration damping is additionally carried out.

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