CN109062036B - Vibration harmonic iterative control system based on transfer function - Google Patents
Vibration harmonic iterative control system based on transfer function Download PDFInfo
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- CN109062036B CN109062036B CN201810598233.4A CN201810598233A CN109062036B CN 109062036 B CN109062036 B CN 109062036B CN 201810598233 A CN201810598233 A CN 201810598233A CN 109062036 B CN109062036 B CN 109062036B
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- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B13/00—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion
- G05B13/02—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric
- G05B13/04—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators
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Abstract
The invention provides a vibration harmonic iterative control system based on a transfer function, which comprises a program control signal source, a vibration exciting unit, a data acquisition unit, harmonic analysis software and harmonic control software. The vibration harmonic iterative control system constructs compensation quantity of harmonic components in the vibration signals output by the vibration exciter based on the transfer function of the vibration exciting unit, and the compensation quantity is superposed into the input quantity, and the effective control of the harmonic components is realized through iterative control, so that the aim of reducing the waveform distortion degree of the vibration signals output by the vibration exciter is fulfilled. The vibration harmonic iterative control system based on the transfer function has the advantages of simple composition structure, simple and convenient operation process, wide application range and better control stability and control effect on the waveform distortion of the vibration signal output by the vibration exciter.
Description
Technical Field
The invention belongs to the technical field of vibration harmonic control, and particularly relates to a vibration harmonic iterative control system based on a transfer function.
Background
In order to improve the signal-to-noise ratio, the displacement amplitude of the vibration signal output by the vibration exciter is gradually increased along with the reduction of the frequency. However, the nonlinearity of systems such as an elastic restoring device and a magnetic circuit structure in the vibration exciter gradually increases with the increase of the displacement amplitude, and further causes the superposition of higher harmonic components on the output vibration signal, thereby generating waveform distortion. The waveform distortion of the vibration signal output by the vibration exciter can seriously restrict the application of the vibration exciter in vibration environment simulation, vibration measurement sensor calibration and other occasions needing to generate high-precision single-frequency vibration exciting signals.
The waveform distortion degree (controlling harmonic components) of the low-frequency vibration signal output by the vibration exciter can be effectively reduced by constructing a closed-loop feedback control system. However, the control effect of the feedback control system on the waveform distortion is related to the frequency response characteristic and the feedback depth (amplification factor on the feedback channel) of the system to be controlled. In general, a vibration exciter has a large nonlinear characteristic at a low frequency, and in order to achieve a good waveform distortion control effect, deep negative feedback control is generally applied. Furthermore, vibration exciters generally have a phase lag response characteristic. With the increase of feedback depth and phase lag, the control system will have unstable phenomena such as self-oscillation or positive feedback, etc., which seriously affects the control effect. In order to achieve better feedback control effect, it is usually necessary to design a controller (such as a PID controller) with a complicated structure in the control system, and to perform system calibration by repeatedly adjusting relevant parameters. However, the introduction of a controller inevitably increases the complexity of the feedback control system and the difficulty of parameter adjustment.
Disclosure of Invention
In order to effectively solve the problems of complex system structure, high parameter adjustment difficulty, high stability requirement and the like in the process of realizing the waveform distortion control of the vibration signal output by the vibration exciter through a closed-loop feedback control system, the invention provides a vibration harmonic iterative control system based on a transfer function to complete the open-loop control of the waveform distortion of the vibration signal output by the vibration exciter.
The vibration harmonic wave iteration control system based on the transfer function comprises a program control signal source, a vibration exciting unit, a data acquisition unit, harmonic wave analysis software and harmonic wave control software; the vibration exciting unit comprises a vibration exciter system and a vibration detecting unit; the vibration exciter system comprises a power amplifier and a vibration exciter; the vibration detection unit comprises a vibration acceleration sensor and an amplifier or an adapter; the data acquisition unit comprises a data acquisition card and a computer; the harmonic control software comprises a calculation module, a reverse phase module and a superposition module; harmonic analysis software and harmonic control software are installed in the computer.
The program control signal source generates a current input quantity, and the current input quantity is amplified by the power amplifier and drives the vibration exciter to generate a vibration acceleration signal; the vibration acceleration signal output by the vibration exciter is detected by a vibration detection unit, and is sent to a computer after being collected by a data acquisition card; the harmonic analysis software calculates and obtains the fundamental frequency contained in the output vibration acceleration signal, the frequency, the amplitude, the phase and the corresponding waveform distortion value of each order of harmonic component, and judges whether the waveform distortion value meets the requirement of being less than or equal to the set waveform distortion degree, the waveform distortion degree requirement refers to the maximum allowable value of the waveform distortion degree of the output vibration acceleration signal generated by the vibration exciter to be controlled, if so, the current input quantity is kept to drive the vibration exciter to generate the vibration acceleration signal; if not, implementing iterative control of waveform distortion of the vibration acceleration signal output by the vibration exciter by adopting harmonic control software.
Obtaining the current input quantity: in the frequency range needing waveform distortion control, based on the acceleration transfer function of the vibration exciting unit and the frequency, amplitude and phase requirements of a target vibration acceleration signal to be generated by a vibration exciter to be controlled, the target vibration acceleration signal is used as the output quantity of the acceleration transfer function, the corresponding input quantity frequency, amplitude and phase are obtained through calculation, and the input quantity is used as the current input quantity.
The harmonic control software respectively takes each order of harmonic component in the output vibration acceleration signal as the input quantity of the acceleration transfer function of the vibration excitation unit, and calculates the frequency, the amplitude and the phase of the input compensation quantity corresponding to each order of harmonic component by using a calculation module; after the input compensation quantity is inverted by an inverting module, a superposition module is used for superposing the input compensation quantity with the current input quantity to obtain a corrected input quantity; and finally, replacing the current input quantity with the correction input quantity, and driving a vibration exciter by a program control signal source and a power amplifier to generate a vibration acceleration signal with a corrected harmonic component based on the current input quantity, thereby completing the whole iterative control process.
The program control signal source is an arbitrary waveform signal generator.
The control system can realize open-loop control of harmonic components in the vibration signals output by the vibration exciter, has the advantages of simple composition structure, simple and convenient operation process and wide application range, and has better control stability and control effect on waveform distortion of the vibration signals output by the vibration exciter.
Drawings
FIG. 1 is a diagram of the iterative control system for vibration harmonics based on transfer function.
FIG. 2 is a flow chart of the acceleration transfer function identification of the vibration exciting unit according to the present invention.
Detailed Description
The invention is described in detail below with reference to the accompanying drawings:
taking an example of detecting an output vibration signal of a vibration exciter by adopting a vibration acceleration sensor in a vibration detection unit, as shown in fig. 1, a vibration harmonic iterative control system based on a transfer function comprises a program control signal source, a vibration excitation unit, a data acquisition unit, harmonic analysis software and harmonic control software; the vibration exciting unit comprises a vibration exciter system and a vibration detecting unit; the vibration exciter system comprises a power amplifier and a vibration exciter; the vibration detection unit comprises a vibration acceleration sensor and an amplifier or an adapter; the data acquisition unit comprises a data acquisition card and a computer; the harmonic control software comprises a calculation module, a reverse phase module and a superposition module; harmonic analysis software and harmonic control software are installed in the computer.
The program control signal source generates a current input quantity, and the current input quantity is amplified by the power amplifier and drives the vibration exciter to generate a vibration acceleration signal; the vibration acceleration signal output by the vibration exciter is detected by a vibration detection unit, and is sent to a computer after being collected by a data acquisition card; the harmonic analysis software calculates and obtains the fundamental frequency contained in the output vibration acceleration signal, the frequency, the amplitude, the phase and the corresponding waveform distortion value of each order of harmonic component, and judges whether the waveform distortion value meets the requirement of being less than or equal to the set waveform distortion degree, the waveform distortion degree requirement refers to the maximum allowable value of the waveform distortion degree of the output vibration acceleration signal generated by the vibration exciter to be controlled, if so, the current input quantity is kept to drive the vibration exciter to generate the vibration acceleration signal; if not, implementing iterative control of waveform distortion of the vibration acceleration signal output by the vibration exciter by adopting harmonic control software.
Obtaining the current input quantity: in the frequency range needing waveform distortion control, based on the acceleration transfer function of the vibration exciting unit and the frequency, amplitude and phase requirements of a target vibration acceleration signal to be generated by a vibration exciter to be controlled, the target vibration acceleration signal is used as the output quantity of the acceleration transfer function, the corresponding input quantity frequency, amplitude and phase are obtained through calculation, and the input quantity is used as the current input quantity.
The harmonic control software respectively takes each order of harmonic component in the output vibration acceleration signal as the input quantity of the acceleration transfer function of the vibration excitation unit, and calculates the frequency, the amplitude and the phase of the input compensation quantity corresponding to each order of harmonic component by using a calculation module; after the input compensation quantity is inverted by an inverting module, a superposition module is used for superposing the input compensation quantity with the current input quantity to obtain a corrected input quantity; and finally, replacing the current input quantity with the correction input quantity, and driving a vibration exciter by a program control signal source and a power amplifier to generate a vibration acceleration signal with a corrected harmonic component based on the current input quantity, thereby completing the whole iterative control process.
The program control signal source is any waveform signal generator and can be controlled by computer software to output a single-frequency signal with set frequency, amplitude and phase or a superposed signal of a plurality of single-frequency signals.
In order to realize iterative control of waveform distortion of a vibration acceleration signal output by a vibration exciter, firstly, an acceleration transfer function of the vibration exciter unit is identified and obtained based on an acceleration transfer function identification flow of the vibration exciter unit shown in fig. 2, and the method specifically comprises the following steps:
(a) selecting a plurality of test frequency points in a certain frequency range, and driving a vibration exciter by a program control signal source and a power amplifier to generate vibration output signals corresponding to the frequency points; the lower limit value of the frequency range is far smaller than the lower limit frequency of the vibration exciter needing to apply waveform distortion control, and the upper limit value is far larger than the upper limit frequency of the vibration exciter needing to apply waveform distortion control;
(b) the vibration detection unit detects and obtains output acceleration signals of the vibration exciter at each frequency point, and the data acquisition unit synchronously acquires the output acceleration signals and input signals generated by the program control signal source;
(c) respectively calculating the amplitude ratio and the phase difference between the output acceleration signal and the input signal corresponding to each frequency point, and further obtaining the acceleration amplitude-frequency and phase-frequency characteristic values corresponding to each frequency point of the vibration excitation unit;
(d) and identifying the acceleration transfer function of the vibration excitation unit by an MATLAB system identification tool based on the acceleration amplitude-frequency and phase-frequency characteristic values of the selected frequency points.
Based on the acceleration transfer function of the vibration exciting unit, the waveform distortion control of the vibration exciting unit to output vibration acceleration signals is realized, and the method specifically comprises the following steps:
1) calculating the current input quantity
In a frequency range needing waveform distortion control, based on an acceleration transfer function of a vibration excitation unit and the frequency, amplitude and phase requirements of a target vibration acceleration signal to be generated by a vibration exciter to be controlled, calculating to obtain corresponding input quantity frequency, amplitude and phase by taking the target vibration acceleration signal as an output quantity of the acceleration transfer function, and taking the input quantity as a current input quantity;
2) driving a vibration exciter to generate a vibration acceleration signal
The program control signal source generates current input quantity, and the current input quantity is input into a power amplifier to drive a vibration exciter to generate a vibration acceleration signal;
3) detecting output vibration acceleration signal
Detecting by using a vibration detection unit to obtain an output vibration acceleration signal of the vibration exciter, and acquiring the output vibration acceleration signal by using a data acquisition unit;
4) calculating harmonic component and waveform distortion value
Calculating the frequency, amplitude, phase and corresponding waveform distortion value of fundamental frequency and harmonic components of each order contained in the output vibration acceleration signal by adopting harmonic analysis software;
5) judging whether the waveform distortion value meets the set requirement
Judging whether the waveform distortion degree value of the output vibration acceleration signal meets the requirement of being less than or equal to the set waveform distortion degree, wherein the waveform distortion degree requirement refers to the maximum allowable value of the waveform distortion degree of the output vibration acceleration signal generated by the vibration exciter to be controlled, and if so, keeping the current input quantity to drive the vibration exciter to generate the vibration acceleration signal; if not, sequentially executing the steps 6) and 7), and then returning to the step 2);
6) calculating an input compensation amount corresponding to each order of harmonic component
Harmonic control software is adopted, each order of harmonic component in the output vibration acceleration signal is used as the input quantity of the acceleration transfer function of the vibration excitation unit, and the frequency, the amplitude and the phase of the input compensation quantity corresponding to each order of harmonic component are calculated by a calculation module;
7) calculating correction input amount and replacing current input amount
And adopting harmonic control software, inverting the input compensation amount corresponding to each order of harmonic of the output vibration acceleration signal by using an inverting module, then overlapping the input compensation amount with the current input amount by using an overlapping module J1 to obtain a corrected input amount, and replacing the current input amount with the corrected input amount.
The vibration acceleration sensor included in the vibration detection unit can be replaced by a vibration speed sensor or a vibration displacement sensor, and when the vibration speed sensor is adopted, the transfer function of the vibration excitation unit is a speed transfer function; when a vibration displacement sensor is used, the transfer function of the vibration exciting unit is a displacement transfer function.
Corresponding to the vibration acceleration sensor, the vibration speed sensor or the vibration displacement sensor, based on the iterative control system of the invention, the control of the waveform distortion of the vibration acceleration signal, the vibration speed signal or the vibration displacement signal output by the vibration exciter to a set range in the whole frequency band to which the waveform distortion control of the output vibration signal is required to be applied can be respectively realized.
Generally speaking, in the present embodiment, based on the transfer function of the vibration excitation unit, a compensation amount of a harmonic component in the vibration signal output by the vibration exciter is constructed and added to the input amount, and effective control of the harmonic component is realized through iterative control, so as to achieve the purpose of reducing the waveform distortion degree of the vibration signal output by the vibration exciter.
The control system can realize open-loop control of harmonic components in the vibration signals output by the vibration exciter, has the advantages of simple structure, simple and convenient operation process and wide application range, and has better control stability and control effect on waveform distortion of the vibration signals output by the vibration exciter.
The embodiments described in the specification are merely illustrative of implementation forms of the inventive concept, and the scope of the present invention should not be considered to be limited to the specific forms set forth in the embodiments, but rather to equivalent technical means that can be conceived by those skilled in the art based on the inventive concept.
Claims (2)
1. Vibration harmonic iterative control system based on transfer function is characterized in that: the system comprises a program control signal source, a vibration exciting unit, a data acquisition unit, harmonic analysis software and harmonic control software; the vibration exciting unit comprises a vibration exciter system and a vibration detecting unit; the vibration exciter system comprises a power amplifier and a vibration exciter; the vibration detection unit comprises a vibration acceleration sensor and an amplifier or an adapter; the data acquisition unit comprises a data acquisition card and a computer; the harmonic control software comprises a calculation module, a reverse phase module and a superposition module; harmonic analysis software and harmonic control software are installed in a computer;
the program control signal source generates a current input quantity, and the current input quantity is amplified by the power amplifier and drives the vibration exciter to generate a vibration acceleration signal; the vibration acceleration signal output by the vibration exciter is detected by a vibration detection unit, and is sent to a computer after being collected by a data acquisition card; the harmonic analysis software calculates and obtains the fundamental frequency contained in the output vibration acceleration signal, the frequency, the amplitude, the phase and the corresponding waveform distortion degree value of each order of harmonic component, and judges whether the waveform distortion degree value meets the requirement of being less than or equal to the set waveform distortion degree, the waveform distortion degree requirement refers to the maximum allowable value of the waveform distortion degree of the output vibration acceleration signal generated by the vibration exciter, if so, the current input quantity is kept to drive the vibration exciter to generate the vibration acceleration signal; if not, implementing iterative control on waveform distortion of the vibration acceleration signal output by the vibration exciter by adopting harmonic control software;
obtaining the current input quantity: in a frequency range needing waveform distortion control, based on an acceleration transfer function of a vibration excitation unit and the frequency, amplitude and phase requirements of a target vibration acceleration signal to be generated by a vibration exciter to be controlled, calculating to obtain corresponding input quantity frequency, amplitude and phase by taking the target vibration acceleration signal as an output quantity of the acceleration transfer function, and taking the input quantity as a current input quantity;
the harmonic control software respectively takes each order of harmonic component in the output vibration acceleration signal as the input quantity of the acceleration transfer function of the vibration excitation unit, and calculates the frequency, the amplitude and the phase of the input compensation quantity corresponding to each order of harmonic component by using a calculation module; after the input compensation quantity is inverted by an inverting module, a superposition module is used for superposing the input compensation quantity with the current input quantity to obtain a corrected input quantity; and finally, replacing the current input quantity with the correction input quantity, and driving a vibration exciter by a program control signal source and a power amplifier to generate a vibration acceleration signal with a corrected harmonic component based on the current input quantity, thereby completing the whole iterative control process.
2. The transfer function-based vibration harmonic iterative control system of claim 1, wherein: the program control signal source is an arbitrary waveform signal generator.
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Effective date of registration: 20211206 Address after: 030600 No. 83 Jingwei North Road, Yuci District, Jinzhong City, Shanxi Province Patentee after: Jinzhong Sanming Hydraulic Machinery Co.,Ltd. Address before: 030024 No. 79 West Main Street, Wan Berlin District, Shanxi, Taiyuan, Yingze Patentee before: Taiyuan University of Technology |