Resonance method for a vibration system, a converter, an excitation unit and vibration system

Abstract

The invention relates to a resonance method (1) for a vibration system (2) for the resonant vibration of an excitation unit (4) having a vibrating mass (3), comprising the steps of detecting a deflection (5) for a deflection (x) of the vibrating mass (3), calculating a speed (6) for a speed (v) of the vibrating mass (3) by way of differentiating the deflection (x), generating a phase position (7) for a mechanical phase position (ϴm) by way of the deflection (x) and the speed (v), correcting a phase position (8) for the mechanical phase position (ϴm) by way of a correction value (kϴ) to form a corrected phase position (ϴk), calculating a frequency (9) for an electrical angular frequency (ωel) by way of at least one P-regulation on the basis of the corrected phase position (ϴk), calculating a phase position (10) for an electrical phase position (ϴel) by way of integration on the basis of the electrical angular frequency (ωel), calculating a factor (11) for a correction factor (kF) by way of a trigonometric function on the basis of the electrical phase position (ϴel) and setpoint value application (12) of the correction factor (kF) to an excitation setpoint value (13) in order to generate a corrected excitation setpoint value (14). The invention furthermore relates to a converter (20), an excitation unit (4) having the converter (20), and the vibration system (2) having the excitation unit (4) and the vibrating mass (3).

Description

[0001] The invention relates to a resonance method for a vibration system for resonant vibration of an excitation unit with a vibration mass. Furthermore, the invention relates to a converter, the excitation unit, and the vibration system.

[0002] Industrial applications with an electromechanical excitation unit for generating vibrations of a vibrating mass, in which an oscillating system, hereinafter referred to as the vibration system, is to be excited with the vibrating mass in the range of a resonance frequency, generally require a determination or estimation of this resonance frequency or the establishment of the state of resonant vibration of the excitation unit and the vibrating mass to be set into vibration in order to be able to control or regulate the operating behavior of the vibration system in an energy-efficient, reliable and low-effort manner.

[0003] The excitation unit usually comprises electromagnets, which can be operated by means of electrical converters and cause the oscillating mass to oscillate based on inductive energy transfer.

[0004] Even small deviations in the resonant oscillation of the excitation unit and the oscillating mass can lead to significant losses in energy efficiency / efficiency or the quality of the desired operating behavior / reliability of the respective application.

[0005] For example, the determination of the resonance frequency or the steady-state, resonant vibration state of the excitation unit and the vibration mass, which was previously carried out separately from the actual operation, often results in considerable downtimes for corresponding machines and devices in production use, which generally require additional effort to the respective production process and thus also cause not insignificant costs.

[0006] Such a vibration system is used, for example, as a friction welding machine or vibratory conveyor.

[0007] The basic process of such a vibration system can be briefly outlined using the example of a friction welding machine. To weld a first workpiece to a second workpiece, the vibration mass, which comprises a first workpiece carrier and the first workpiece connected to it, is forced into vibration by an excitation unit. The vibration mass is typically mounted so that it can vibrate using a spring device.

[0008] To generate the frictional heat for this production process, the first workpiece is rubbed against the second workpiece, which is connected to a generally stationary second workpiece carrier, until it is welded.

[0009] If this excitation occurs at the resonance frequency, i.e. in vibrational resonance between the excitation unit and the vibration mass, the desired vibration can be generated with a particularly low energy expenditure.

[0010] This resonance frequency of the vibration system is largely determined by the vibration mass, which here comprises the first workpiece, and the vibration-capable mounting of the vibration mass, i.e. the spring stiffness of the spring device used.

[0011] Since the first workpiece contributes to the oscillating mass, after a workpiece change of the first tool, in particular if the mass of the first workpiece changes, a renewed determination of the resonance frequency, i.e. the resonant oscillation state of the excitation unit and the oscillating mass, is mandatory and requires considerable effort.

[0012] Otherwise, the vibration system will not operate optimally, particularly in terms of energy, which will significantly reduce its efficiency or possibly even prevent the desired vibration amplitude from being achieved, and the required welding quality will be rather poor.

[0013] Previous applications, such as friction welding, predominantly use preoperative methods to determine / estimate the resonance frequency in order to subsequently excite the oscillating mass using the excitation unit and achieve the required resonant oscillation state of the excitation unit and the oscillating mass.

[0014] The desired resonance frequency is determined by means of an independent run-up test before the actual production process and is then operated with this frequency until a new run-up test becomes necessary due to the use of a new first workpiece or until undesirable deviations in the production process that occur in the meantime make a correction necessary.

[0015] This means that the vibration excitation is only carried out on the basis of the frequency determined by the run-up test, which often only inadequately matches the resonance frequency required in the actual production process for the resonant vibration state of the excitation unit and the vibration mass, which can also change during operation in the production process due to wear, temperature differences, material removal, etc.

[0016] DE 10 2011 119 949 A1 relates to a control device, in particular to a yaw rate sensor device with a harmonic reference variable or with a harmonic setpoint signal, as well as to a method for operating a control device with a harmonic reference variable. The control device comprises a sensor unit that outputs a measurement signal representing a deflection of an oscillator along an excitation direction. A main controller unit derives a control signal for an actuator unit from the measurement signal and a harmonic setpoint signal, so that the actuator unit counteracts a deviation of the oscillator's deflection from a target amplitude of a harmonic resonance oscillation.

[0017] US 2019 / 165247 A1 relates to controlling the amplitude of a mechanical excitation for a load by a piezoelectric actuator with an ultrasonic stack. For this purpose, a closed-loop feedback controller determines in real time the actual amplitude of the mechanical excitation at the end of the piezoelectrically driven ultrasonic stack.

[0018] US 7,148,636 B2 relates to a motor drive controller, in particular a motor drive controller for controlling a linear vibration motor, which operates a motor based on its drive current.

[0019] The invention is therefore based on the object of proposing a resonance method, a converter, an excitation unit and a vibration system, which continuously determine a required resonant vibration state for the resonant vibration of the excitation unit with a vibration mass of the vibration system during production operation and the vibration system is operated therewith.

[0020] The object is achieved by a resonance method having the features specified in claim 1, by a converter according to the features specified in claim 8, by an excitation unit having the converter according to the features specified in claim 11 and by an oscillation system having the excitation unit according to the features specified in claim 13.

[0021] To achieve the object, a resonance method for a vibration system for resonant vibration of an excitation unit with a vibration mass is proposed, comprising the steps of detecting a deflection of the vibration mass, forming a speed of the vibration mass by differentiating the deflection, generating a phase position of a mechanical phase position by means of the deflection and the speed, correcting the phase position of the mechanical phase position by means of a correction value to a corrected phase position, forming a frequency of an electrical angular frequency by means of at least one P-control on the basis of the corrected phase position, forming an electrical phase position by means of integration on the basis of the electrical angular frequency,a factoring of a correction factor using a trigonometric function based on the electrical phase position and a setpoint application of an excitation setpoint with the correction factor to generate a corrected excitation setpoint.

[0022] The method is advantageously based on the conceptual restriction of the freedom of movement (the degree of freedom) of the oscillating mass and on its resonance frequency (here the electrical angular frequency) relative to the excitation unit.

[0023] The actual position of the deflection of the oscillating mass recorded by the deflection detection is converted into a vector, the abscissa is the recorded deflection and the ordinate is the speed of the oscillating mass formed by the speed formation as a differentiation of the deflection according to the formula v t = dx dt where v is the velocity, x is the detected displacement and t is the time.

[0024] The mechanical phase position generated by the phase position generation is advantageously obtained, for example, by means of an arctan2 function based on the deflection and the speed according to the formula θm = arctan 2 x v where Θ m is the mechanical phase position, v is the velocity and x is the displacement.

[0025] Preferably, a normalized speed is selected as the speed for generating the mechanical phase positions.

[0026] By means of the phase position correction of the mechanical phase position, the corrected phase position is continuously and advantageously obtained by means of a correction value.

[0027] For the frequency generation of the electrical angular frequency, instead of the P control (with gain component K p ), a PI control (with gain component K p and integral component I) or even a PID control (with gain component K p , integral component I and differentiation component D) can be used on the basis of the corrected phase position, which can increase the quality of the P control in terms of greater control quality.

[0028] The resulting electrical angular frequency is also to be understood as the current oscillation frequency (requested resonance frequency) or the last current oscillation frequency (last requested resonance frequency). Therefore, a specific learning of the control system is not necessary.

[0029] To determine the phase position of the electrical phase, the electrical angular frequency is advantageously integrated.

[0030] The correction factor is calculated using the trigonometric function based on the electrical phase position, for example using a sine function according to the formula kF = sin θel where k F is the correction factor and Θ el is the electrical phase position.

[0031] By means of the setpoint application, the excitation setpoint is advantageously corrected as an electrical value for a vibration-generating force of the excitation unit for exciting the vibrating mass with the correction factor, such that a corrected electrical value for the vibration-generating force is generated as a corrected excitation setpoint for the resonant vibration of the excitation unit and the vibrating mass to be achieved.

[0032] With this corrected excitation setpoint, for example, an electromagnet is electrically excited by the excitation unit, which generates the corresponding resonant oscillation of the excitation unit and the oscillating mass.

[0033] Advantageous embodiments of the resonance method are specified in the dependent claims.

[0034] In a first advantageous embodiment of the resonance method, the resonance method comprises the step of speed normalization of the speed by means of the electrical angular frequency to a standardized speed, wherein the speed is divided by the electrical angular frequency.

[0035] In order to map the speed to the electrical angular frequency in an advantageous manner, the speed is converted into the standardized speed based on the electrical angular frequency according to the formula vn t = 1 ωel ∗ dx dt where vn is the normalized velocity, ω el is the electrical angular frequency, x is the displacement and t is the time.

[0036] In a further advantageous embodiment of the resonance method, the correction value for the phase position correction is the fed-back electrical phase position and preferably the fed-back electrical phase position is subtracted from the mechanical phase position.

[0037] From the control point of view, this results in a regulated phase position, whereby the mechanical phase position is corrected until the corrected phase position assumes a value of approximately 0.

[0038] The electrical phase position fed back to the mechanical phase position as a correction value in a control loop can also be added to the mechanical phase position, taking into account the signs of the mechanical phase position and the electrical phase position.

[0039] In a further advantageous embodiment of the resonance method, an initial angular frequency is specified for method initialization or the last known electrical angular frequency is used.

[0040] In order to initialize the resonance process, for example at its start, the initial angular frequency can preferably be specified as a parameter during the process initialization, which can also already correspond to the desired resonance frequency.

[0041] It is also advantageous to use the last known electrical angular frequency, e.g. in the event of faults or when restarting the control after a failure of the resonance method.

[0042] In a further advantageous embodiment of the resonance method, the mechanical phase position is determined in particular between a deflection amplitude of the deflection and the speed or between a deflection amplitude of the deflection and the deflection.

[0043] The deflection amplitude can be determined according to the formula xa = x 2 + v 2 where xa is the deflection amplitude, x is the displacement and v is the velocity.

[0044] Preferably, the normalized speed is chosen as the speed for determining the deflection amplitude.

[0045] In a further advantageous embodiment of the resonance method, a deflection signal is detected by a deflection measuring device for deflection detection and the deflection signal is corrected by a DC component depending on the installation location of the deflection measuring device relative to the oscillating mass, wherein the DC component is specified by a DC component parameter or determined by a DC component high-pass filter.

[0046] The deflection measuring device measures the deflection of the oscillating mass relative to a rest position of the oscillating mass and provides the deflection in the deflection signal for further processing by the resonance method.

[0047] By means of the DC component parameter or the DC component high-pass filter, a correction of the deflection measurement value of the deflection with respect to the installation location of the deflection measuring device can be made.

[0048] In a further advantageous embodiment of the resonance method, the excitation setpoint is a setpoint current and the corrected excitation setpoint is a corrected setpoint current.

[0049] The excitation setpoint as an electrical value for the vibration-generating force and the corrected excitation setpoint as a corrected electrical value for the vibration-generating force for controlling the electromagnets, z.B. by means of an electrical converter, is advantageously designed as a setpoint current for generating a force-generating vibration excitation. In principle, a corresponding setpoint voltage is also suitable for this purpose.

[0050] In a further advantageous embodiment of the resonance method, the electrical angular frequency is monitored for disturbances during the resonant oscillation of the excitation unit and the oscillating mass.

[0051] For this purpose, the electrical angular frequency can advantageously be monitored by a lower frequency limit to detect an undershoot of the electrical angular frequency and / or an upper frequency limit to detect an undershoot of the electrical angular frequency.

[0052] To achieve the object, a converter is further proposed which comprises a detection means designed to detect the deflection of a deflection of the oscillating mass, a first formation means designed to form the speed of the oscillating mass by differentiating the deflection, a generation means designed to generate the phase position of a mechanical phase position by means of the deflection and the speed, a correction means designed to correct the phase position of the mechanical phase position by means of a correction value to a corrected phase position, a second formation means designed to form the frequency of an electrical angular frequency by means of at least one P-control on the basis of the corrected phase position, a third formation means designed to form the phase position of an electrical phase position by means of integration on the basis of the electrical angular frequency, a fourth formation means,designed to factor a correction factor by means of a trigonometric function based on the electrical phase position and a loading means designed to apply the correction factor to an excitation setpoint to generate a corrected excitation setpoint.

[0053] In a first advantageous embodiment of the converter, the converter has a standardization means designed to standardize the speed by means of the electrical angular frequency to a standardized speed, wherein the speed is divisible by the electrical angular frequency.

[0054] In a further advantageous embodiment of the converter, the returned electrical phase position is provided as a correction value for the phase position correction and the returned electrical phase position can preferably be subtracted from the mechanical phase position.

[0055] Basically, the converter is designed to carry out the resonance method according to the invention described above.

[0056] To achieve the object, an excitation unit is also proposed which has at least one electromagnet for exciting the oscillating mass, the converter according to the invention for operating the at least one electromagnet and a deflection measuring device for measuring the deflection of the oscillating mass relative to a rest position of the oscillating mass.

[0057] The deflection measured by the deflection measuring device is transmitted by a deflection signal to the detection means of the converter for deflection detection.

[0058] In an advantageous embodiment of the excitation unit, the excitation unit has at least one spring element, wherein the at least one spring element is connected to the oscillating mass.

[0059] Solutions with two or more spring elements are also conceivable, by means of which the oscillating mass is mounted in an oscillating manner.

[0060] To solve the problem, a vibration system is also proposed which has the excitation unit according to the invention and the vibration mass.

[0061] In an advantageous embodiment of the vibration system, the vibration system is designed as a friction welding device or as a transport device.

[0062] Transport devices include, for example, conveyor devices for material transport (so-called vibrators or vibrating conveyors), which transport their goods using vibrating conveyor belts.

[0063] The above-described properties, features, and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more readily understood in connection with the following description of the exemplary embodiments, which are explained in more detail in conjunction with the figures. It shows: FIG 1 shows a structural diagram of the resonance method according to the invention, FIG 2 shows a schematic control representation of the resonance method according to the invention, and FIG 3 shows a schematic representation of a friction welding device with the converter according to the invention, the excitation unit according to the invention and the vibration system according to the invention.

[0064] The FIG 1 shows a structure diagram of the resonance method 1 according to the invention with method steps for a resonant oscillation of an excitation unit with an oscillating mass.

[0065] During the deflection detection 5, a deflection of the oscillating mass is detected. A deflection signal detected by a deflection measuring device can be corrected by a DC component relative to the oscillating mass depending on the installation location of the deflection measuring device. The DC component can be specified by a DC component parameter 34 or determined by a DC component high-pass filter 19.

[0066] By differentiating the deflection, a speed of the oscillating mass is formed during speed formation 6, whereby the speed is converted into a standardized speed based on the electrical angular frequency by dividing the speed by the electrical angular frequency.

[0067] In phase position generation 7, a mechanical phase position is generated based on the deflection and the speed.

[0068] Via the phase position correction 8, the mechanical phase position is converted into a corrected phase position using a correction value. The correction value is the electrical phase position fed back in a control loop, with the fed-back electrical phase position preferably being subtracted from the mechanical phase position.

[0069] Frequency generation 9 of an electrical angular frequency is carried out by means of at least one P-control based on the corrected phase position. For frequency generation 9, the P-control can also be implemented as a PI control or a PID control.

[0070] For a process initialization 16, an initial angular frequency can be specified or the last known electrical angular frequency can be used.

[0071] Furthermore, for fault monitoring 33, the electrical angular frequency can be monitored for disturbances during the resonant oscillation of the excitation unit and the oscillating mass. Typical disturbances can be caused, for example, by mechanical defects during the oscillation of the oscillating mass, so that the required electrical angular frequency can become too low or too high, and the resonance process may have to be aborted.

[0072] When forming the phase position 10 of an electrical phase position, an integration is carried out on the basis of the electrical angular frequency.

[0073] During the factor formation 11 of a correction factor, a trigonometric function based on the electrical phase position is used and the correction factor corrects an excitation setpoint to a corrected excitation setpoint during a setpoint application 12.

[0074] In FIG 2 A schematic control representation of the resonance method 1 according to the invention is shown. The resonance method 1 can be executed by a converter, in particular by a control unit of the converter.

[0075] A detection means 21 is designed to detect a deflection x of the oscillating mass. A deflection signal detected as deflection x by a deflection measuring device is corrected by a DC component by a high-pass filter 37 of a DC component high-pass filter 19, depending on the installation location of the deflection measuring device relative to the oscillating mass.

[0076] A first forming means 22 differentiates the deflection x by means of the velocity formation 6 to a velocity v of the oscillating mass. The velocity v is further converted by a normalization means 35 in a velocity normalization 15 based on a fed-back electrical angular frequency ω el into a standardized velocity vn by dividing the velocity v by the electrical angular frequency ω el.

[0077] A generating means 23 is designed to generate a phase position 7 of a mechanical phase position Θ m, which is carried out on the basis of the deflection x and the speed v.

[0078] A correction means 24 is designed for phase position correction 8 of the mechanical phase position Θ m, wherein the mechanical phase position Θ m is converted into a corrected phase position Θ k by means of a correction value k Θ . A fed-back electrical phase position Θ el is used as the correction value k Θ , wherein the fed-back electrical phase position Θ el is subtracted from the mechanical phase position Θ m.

[0079] A second forming means 25 is designed to generate the frequency 9 of the electrical angular frequency ω el using a P-control, which can also be a PI control or a PID control, based on the corrected phase position Θ k. The electrical angular frequency ω el is returned at this point to the normalization means 35 for the speed normalization 15.

[0080] An initial angular frequency ω in can be specified by an initialization means 36 for the process initialization 16.

[0081] A third forming means 26 generates a phase position 10 of the electrical phase position Θ el by means of integration based on the electrical angular frequency ω el . At this point, the electrical phase position Θ el is fed back to the correction means 24 for the phase position correction 8.

[0082] A fourth forming means 27 performs a factor formation 11 of a correction factor k F by means of a trigonometric function based on the electrical phase position Θ el.

[0083] An actuating means 28, designed to apply a setpoint 12 to an excitation setpoint 13 in the form of a setpoint current IS with the correction factor k F , generates a corrected excitation setpoint 14 in the form of a corrected setpoint current I Sk . This corrected setpoint current I Sk is used, in particular, to operate an electromagnet which is included in the excitation unit and excites the oscillating mass to resonant oscillation.

[0084] By means of FIG 3 a schematic representation of a friction welding device 32 with the converter 20 according to the invention, the excitation unit 4 according to the invention and the vibration system 2 according to the invention is shown.

[0085] The vibration system 2 is designed here as an example as a friction welding device 32 with the excitation unit 4 and an oscillating mass 3.

[0086] A first fastening means 41 for a first workpiece 43 is arranged on the vibration mass 3. The vibration mass 3 with the first fastening means 41 and the first workpiece 43 is mounted in a vibration-capable manner.

[0087] Directly opposite the first workpiece 43, a second workpiece 44 is connected to a second fastening means 42. The second workpiece 44 is firmly fixed to the second fastening means 42 relative to the first workpiece 43 and is mounted in a non-oscillating manner.

[0088] The excitation unit 4 for exciting the vibration of the oscillating mass 3 comprises the converter 20, an electromagnet 29, a further electromagnet 30, a first and second spring element 38, 39 for the oscillatory mounting of the oscillating mass 3, a deflection measuring device 18 and a deflection signal transmitted from the deflection measuring device 18 to the converter 20, which has a measured actual value of the deflection.

[0089] The deflection is measured by means of the deflection measuring device 18 relative to a rest position 31 of the oscillating mass 3.

[0090] The control method according to the invention can be carried out by means of the converter 20, in particular by means of the control unit 40 of the converter 20.

[0091] During operation of the friction welding device 32, the first workpiece 43, which is attached to the first fastening means 41 of the vibration mass 3, is set into resonant vibrations with the excitation unit 4. The vibrating first workpiece 43 rubs against the firmly fixed and non-vibrating second workpiece 44, generating frictional heat and welding both workpieces 43, 44 together in an energy-efficient manner and with high manufacturing quality.

Claims

1. Resonance method (1) for a vibration system (2) for the resonant vibration of an excitation unit (4) with a vibrating mass (3), having the steps - deflection detection (5) of a deflection (x) of the vibrating mass (3), wherein a deflection signal (17) is detected by a deflection measuring apparatus (18) for deflection detection (5) and the deflection signal (17) is corrected by a DC component relative to the vibrating mass (3) as a function of the installation location of the deflection measuring apparatus (18), wherein the DC component is predetermined by a DC component parameter (34) or determined by a DC component high-pass filter (19), - velocity formation (6) of a velocity (v) of the vibrating mass (3) by means of differentiating the deflection (x), - phase position generation (7) of a mechanical phase position (Θm) by means of the deflection (x) and the velocity (v), - phase position correction (8) of the mechanical phase position (Θm) by means of a correction value (kΘ) to form a corrected phase position (Θk), - frequency formation (9) of an electrical angular frequency (ωel) by means of at least one P-regulation on the basis of the corrected phase position (Θk), - phase position formation (10) of an electrical phase position (Θel) by means of integration on the basis of the electrical angular frequency (ωel), - factor formation (11) of a correction factor (kF) by means of a trigonometric function on the basis of the electrical phase position (Θel) and - setpoint value application (12) of the correction factor (kF) to an excitation setpoint value (13) in order to generate a corrected excitation setpoint value (14).

2. Resonance method (1) according to claim 1, having the step of velocity standardisation (15) of the velocity (v) by means of the electrical angular frequency (ωel) to form a standardised velocity (vn), wherein the velocity (v) is divided by the electrical angular frequency (ωel).

3. Resonance method (1) according to one of claims 1 or 2, wherein for phase position correction (8), the correction value (kΘ) is the fed-back electrical phase position (Θel) and the fed-back electrical phase position (Θel) is preferably subtracted from the mechanical phase position (Θm).

4. Resonance method (1) according to one of the preceding claims, wherein an initial angular frequency (ωin) is specified or the last known electrical angular frequency (ωel) is used for method initialisation (16).

5. Resonance method (1) according to one of the preceding claims, wherein the mechanical phase position (Θm) is determined between a deflection amplitude (xa) of the deflection (x) and the velocity (v) or as a phase position between a deflection amplitude (xa) of the deflection (x) and the deflection (x).

6. Resonance method (1) according to one of the preceding claims, wherein the excitation setpoint value (13) is a setpoint current (IS) and the corrected excitation setpoint value (14) is a corrected setpoint current (ISk).

7. Resonance method (1) according to one of the preceding claims, wherein the electrical angular frequency (ωel) is monitored for disturbances in the resonant vibration of the excitation unit (4) and the vibrating mass (3) for fault monitoring (33).

8. Converter (20), having - a detection means (21), configured for deflection detection (5) of a deflection (x) of the vibrating mass (3), wherein a deflection signal (17) is detected by a deflection measuring apparatus (18) for deflection detection (5) and the deflection signal (17) is corrected by a DC component relative to the vibrating mass (3) as a function of the installation location of the deflection measuring apparatus (18), wherein the DC component is predetermined by a DC component parameter (34) or determined by a DC component high-pass filter (19), - a first forming means (22), configured for velocity formation (6) of a velocity (v) of the vibrating mass (3) by means of differentiating the deflection (x), - a generating means (23), configured for phase position generation (7) of a mechanical phase position (Θm) by means of the deflection (x) and the velocity (v), - a correction means (24), configured for phase position correction (8) of the mechanical phase position (Θm) by means of a correction value (kΘ) to form a corrected phase position (Θk), - a second forming means (25), configured for frequency formation (9) of an electrical angular frequency (ωel) by means of at least one P-regulation on the basis of the corrected phase position (Θk), - a third forming means (26), configured for phase position formation (10) of an electrical phase position (Θel) by means of integration on the basis of the electrical angular frequency (ωel), - a fourth forming means (27), configured for factor formation (11) of a correction factor (kF) by means of a trigonometric function on the basis of the electrical phase position (Θel) and - an application means (28), configured for setpoint value application (12) of the correction factor (kF) to an excitation setpoint value (13) in order to generate a corrected excitation setpoint value (14).

9. Converter (20) according to claim 8, having a standardisation means (35), configured for velocity standardisation (15) of the velocity (v) to form a standardised velocity (vn) by means of the electrical angular frequency (ωel), wherein the velocity (v) can be divided by the electrical angular frequency (ωel).

10. Converter (20) according to one of claims 8 or 9, wherein for phase position correction (8) the fed-back electrical phase position (Θel) is provided as the correction value (kΘ) and the fed-back electrical phase position (Θel) can preferably be subtracted from the mechanical phase position (Θm).

11. Excitation unit (4), having - at least one electromagnet (29) for exciting the vibrating mass (3), - a converter (20) according to one of claims 8 to 10 for operating the at least one electromagnet (29) and - a deflection measuring apparatus (18) for measuring the deflection (x) of the vibrating mass (3) with regard to a resting position (31) of the vibrating mass (3).

12. Excitation unit (4) according to claim 11, having at least one spring element (38), wherein the at least one spring element (38) is connected to the vibrating mass (3).

13. Vibration system (2), having an excitation unit (4) according to one of claims 11 or 12 and the vibrating mass (3).

14. Vibration system (2) according to claim 13, prepared as a friction welding apparatus (32) or as a transport apparatus.

Images