SU1254310A1 - Device for detecting resonance frequency of object - Google Patents

Abstract

The invention relates to measurement technology and can be used in the field of engineering. The aim of the invention is to improve the detection accuracy of resonant frequencies by averaging the results of two measurements. - The device contains a frequency scanner, a master oscillator, a regulator, an amplifier, a shaker with a test object, two vibration transducers, two matching amplifiers, an indicator, a frequency converter - voltage, two memory blocks, a computing unit, two pulse shapers, and a frequency scan control unit . The sweep is carried out with respect to the resonant frequency on both sides. In each scan cycle, the resonance frequency is determined, and the result of the KV measurement is averaged, t sludge. Jyu J O9

Description

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The invention relates to a measurement technique and can be used to determine the dynamic characteristics of objects.

The aim of the invention is to improve the detection accuracy of the resonance frequency by averaging the results of two measurements.

The drawing shows a block diagram of the device.

A device for detecting the resonant frequency of an object contains a frequency scanner 1, a generator 2, an amplitude regulator 3, an amplifier 4, a vibration table 5 with a target object 6 mounted on it and installed on a vibration table 5 and an object 6 of vibration transducer 7 and 8, two matching amplifiers 9 and 10 and an indicator 11, the inputs connected to the outputs of the corresponding matching amplifiers 9 and 10, and the inputs of the latter are connected to the outputs of the corresponding vibration transducers 7 and 8, the converter 12 input ohm connected to the output of the first matching amplifier 9, the output to the second input of the regulator 3 amplitude. In addition, the device is equipped with a voltage-voltage converter 13, a first memory block 14, a computing unit 15 and a recorder 16, a second memory block 17, an INPUT connected to the output of a frequency-voltage converter 13, and a second input of a computing unit 15, successively connected by a pulse former 18 and a sweep control unit 19, the output of which is connected to the input of frequency scanner 1, a second pulse former 20, the input connected to the first input of ers 18 and pulse output indicator 11, a second input coupled to the input transducer 13, the second pulse shaper 20 vtorm output connected to input of the second memory unit 17, and the second input of the first memory block 14 is connected to the output of the first pulse shaper 18.

The device works as follows.

Frequency scanner 1 performs the maximum possible

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of the generator 2 a linear increase in hours from the output of the generator 2, through the amplitude regulator 3 and the power amplifier 4, the signal goes to the shaker 5 with the test object 6 mounted on it, the signal from the vibrator 7 goes through the matching amplifier 9 and the converter 12 to the control input of the amplitude regulator 3, thereby forming an excitation level stabilization circuit. When the frequency changes, the harmonic signals from the outputs of the vibration transducers 7 and 8 through the matching amplifiers 9 and 10 are fed to the indicator 11. In case of excitation frequency coinciding with the self-resonance frequency of the object 6, the amplitude of the vibration of the latter increases sharply, and the oscillation phase changes to TT / 2, which a change in the voltage level at the output of the indicator 11 is caused. With such a frequency sweep rate in the region of resonance, the amplitude and phase of the oscillations do not have time to increase immediately to the established value due to high Nost objects. Therefore, the value of the resonant frequency f, at which the indicator 11 is triggered, is obtained by a certain amount larger than the real value. At the same time, the output of the indicator 11 changes the level of DC voltage from high to low, which causes the pulse shaper 18 to trigger, which generates a pulse of the required duration for introducing a voltage proportional to the frequency value from the frequency converter output to the memory memory unit 14 from the output of the frequency converter 13 -purpose. At the same time, the pulse from the output of the pulse generator 18 is supplied to the scan control unit 19, which reverses the frequency sweep direction at the same speed. With such a change in the excitation frequency, the indicator 11 also works, and the value of the resonant frequency is now lower than the real one. In this case, a change in the voltage at the output of the indicator 11 from a low to a high level triggers the second form of the puller 20 pulses, the output impulse of which introduces a voltage in the second memory block 17 proportional to the frequency value at that moment. From the outputs

blocks 14 and 17 of the voltage memory are supplied to the computational block 15, which determines the exact value of the resonant frequency {d.

The resulting value of f with the recorder 16.

fixes-

Claims (1)

Invention Formula A device for detecting the resonant frequency of an object, containing a series-connected frequency scanner, a generator, regulating output to the second input of the regulator, amplitude, characterized in that, in order to increase accuracy, it is equipped with serially connected frequency-voltage converter, first memory block, computing unit and recorder, second memory block, input connected to converter output frequency and voltage, and output - with the second input of the computing unit, connected in series by the pulse shaper and the sweep control unit, amplitude selector, amplifier, shaker 5 whose stroke is connected to the input block with the test object installed on it and vibration transducers installed on the vibration table and on the object, two matching amplifiers and an indicator, inputs connected to the outputs of the corresponding matching amplifiers, and the inputs of the latter are connected to the outputs of the corresponding vibration transducers, the converter connected to the VG-course first matching amplifier. five o output to the second input of the regulator, amplitude, characterized in that, in order to increase accuracy, it is equipped with serially connected frequency-voltage converter, first memory block, computing unit and recorder, second memory block, input connected to converter output frequency and voltage, and output - with the second input of the computing unit, connected in series by the pulse former and the sweep control unit, the output of which is connected to the input of the unit frequency sweep, the second pulse shaper, the input connected to the input of the first pulse shaper and the indicator output, the second input of which is connected to the converter input, the output of the second pulse shaper is connected to the second input of the second memory block, and the second input of the first memory block is connected to the output the first pulse former. Editor A.Gulko Compiled by V. Lopukhin Tehredm.Hodanich Order 4710/44 Circulation 507 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab. D. 4/5 Production and printing company, Uzhgorod, st. Project, 4 Proofreader E. Sirohman