SU1534432A1 - Device for reproduction of spectrum of random vibration - Google Patents

Abstract

The invention relates to a testing technique and is intended to test products for vibration resistance and vibration resistance. The purpose of the invention is to simplify a device for reproducing a spectrum of random vibration by using single-channel instead of multi-channel memory blocks and reducing the number of adjustable amplifiers. The wideband signal is reproduced alternately from both memory blocks, moreover, if, for example, the signal is reproduced from memory block 3, memory block 4 is used to correct the reproduced part of the spectrum in each of the frequency ranges. The total broadband random signal of a narrowband random signal, the frequency band of which corresponds to the frequency band of the adjustable range, is extracted using a tunable block filter 17 connected by the input to the switch 5, and output to one of the inputs of the two-input adder 16, to the other input the corrected narrow-band signal from the output of the adjustable amplifier 15. Changing the bandwidth of the tunable band-pass filters 2 and 10, the fencing band tra 17, commutation switch key 5 are performed by a command from the synchronization unit 18. The determined functional organization of the synchronization unit 18 and the switch 5 allows to simplify the implementation of the memory unit, reducing the number of adjustable amplifiers. 1 il.

Description

ate

with

4 4

with

1C

amplifiers. The wideband signal is reproduced alternately from both memory blocks, moreover, if, for example, the signal is reproduced from memory block 3, memory block 4 is used to correct the reproduced part of the spectrum in each of the frequency ranges. The total broadband random signal of a narrowband random signal, the frequency band of which corresponds to the frequency band of the adjustable range, is extracted using a tunable block filter 17 connected by the input to the switch 5, and the output to one of the inputs of the two-way adder 16 to the other input which receives the corrected narrow-band signal from the output of the adjustable amplifier 15. Changing the bandwidth of the tunable filters 2 and 10, the band block neither the filter 17, the switching of the keys of the switch 5 is effected by a command from the synchronization unit 18. The determined functional organization of the synchronization unit 18 and the switch 5 allows to simplify the implementation of the memory unit, reducing the number of adjustable amplifiers. 1 il ..

The invention relates to testing equipment, namely, devices for reproducing a spectrum of random vibration, and is intended to test products for vibration resistance and vibration resistance.

The aim of the invention is to simplify a device for reproducing a spectrum of random vibration by using single-channel and single-channel adjustable frequency instead of multi-channel memory blocks.

The drawing shows a block diagram of a device for arranging a spectrum of random vibration.

The device contains a series-connected noise generator 1 and the first band-tunable filter 2, the first 3 and second 4 memory blocks, the switch 5 connected in series, the power amplifier 6, the oscillator 7, the vibration sensor 8, the spectrum analyzer 9 including the second tunable second filter 10 connected in series , quadratic detector 11, integrator 12, made, for example, in the form of a low-pass filter, the output of which is connected to the first input of the comparator unit 13, the second input of the latter is connected to the output setpoint 14, an adjustable amplifier 15, to the input of which the output of the second tunable filter 10 is connected, and to the control input - output of the comparison unit 13, the output of the adjustable amplifier is connected to the first input of the adder 16, to the second

0

The input of which is connected to the output of a tunable fence filter 17, whose input is connected to the input of power amplifier 6, the output of the adder is connected to the input of switch 5, the synchronization unit 18, which is, for example, a program-controlled timer.

The device operates in the Setup and Play modes.

Setup mode.

In the Tuning mode, the signal of the noise generator 1 is converted by the first tunable filter 2 into a narrowband (according to a command from the synchronization unit 18, the bandwidth of the first tunable filter is set corresponding to the first frequency range of the generated spectrum) and through a closed key enters the power amplifier 6, the exciter 7, the vibration sensor 8 and further on the spectrum analyzer 9 (on command from the synchronization unit 18, the bandwidth of the second tunable filter 10 is set equal to the bandwidth the first tunable filter 2). From the output of the second tunable filter 10, the narrowband signal is fed to the input of the adjustable amplifier 15, the gain of the latter is set in accordance with the sign and the error value of the signal dispersion value in the first frequency range and the required signal dispersion value determined by

515

master 14 spectrum command from the block 18 synchronization. The dispersion value in the first-frequency band formation band (in the passband of the second tunable filter 10) is determined at the output of the series-connected quadratic detector 11 and integrator 12, and the error signal arriving at the control input of the adjustable amplifier 15 is removed from the output of the compare block 13 .

The narrowband signal corresponding to the first frequency range of the generated spectrum from the output of the adjustable amplifier 15 is fed to one of two inputs of the adder 16, to the other input of which through the closed keys 5 receives a signal from the second memory block 4 (previously, before both memories are erased). Thus, during the formation of the first frequency band in the adder 16, the narrowband signal corresponding to the first frequency band is summed with the zero signal from the second memory block 4.

The formation of the second frequency range takes place similarly to that described (by a command from the band 18 block synchronizing the first 2 and second 10 tunable filters to be equal to the second frequency range of the generated spectrum) with the difference that one of the inputs of the adder 16 receives a signal from the first 3 memory blocks (recorded during the formation of the previous frequency range) through

closed key eg, and the resulting signal at the output of the adder 16, equal to the sum of the narrow-band signals corresponding to the first and second frequency ranges of the formed spectrum, through the closed key 5 3-o. is recorded in the second memory block 4.

Thus, during the formation of each next frequency range, the narrow-band signals of this range are summed with the total signal obtained during the formation of the previous frequency ranges.

five

five

0

At the end of the process of forming (tuning), the sum signal is recorded in one of the memory blocks over all frequency bands of the spectrum being formed, in the other — the same signal minus the signal corresponding to the last frequency range.

Playback mode.

In the Playback mode, the cm with the required spectrum (obtained after the Setup mode expires) is fed through the power amplifier 6 to the exciter 7 exciter from one of the memory blocks, for example, the first block 3, via closed keys 52 (and 5 4, switch 5). In this mode, sequential correction is performed for each frequency range of the reproduced spectrum.

Consider the process of spectrum correction on the example of a single frequency range.

Let the total signal be supplied to the power amplifier 6 and then to the exciter 7 from the first memory block 3 through the closed keys and 5C (switch 5. At the same time, through the closed key 5

4-2

E1 OT

five

five

0

five

0

five

the same signal arrives at the tunable barrier filter 17, the obstacle band of which, on command from the synchronization unit 18, is tuned to the frequency band of the frequency range being adjusted. It should be noted that the bandwidth of the second tunable filter 10 is also tuned to the frequency band of the adjustable frequency range.

Thus, one input of the adder 16 receives the sum signal from the first memory block 3, except for the narrowband signal cut by the blocking filter 17 in the adjustable frequency band, and the other input is the corrected narrow-band signal from the output a power amplifier 15. After the correction process of this frequency range has been completed (error compensation at the output of comparison unit 13), the sum signal is recorded in the second memory block 4 via a closed commutator key ra 5.

Similarly, the correction of the next frequency range is carried out with the difference that the sum signal is reproduced from the second memory block 4, and the corrected signal is recorded in the first memory block 3.

The switch keys of the switch 5 in the Settings and Play modes are performed by commands from the synchronization unit 18.

Thus, the memory unit is implemented in the form of two channels, each of which alternately reproduces the spectrum of broadband vibration, and during reproduction of the spectrum by one channel of the memory unit the other is used to correct the reproduced spectrum. Such a function of the memory unit is provided by the organization of the synchronization unit and the switch, which allows to simplify the implementation of the memory unit and reduce the number of adjustable amplifiers.

Claims (1)

Invention Formula An apparatus for reproducing a spectrum of random vibration comprising a series-connected noise generator and a first slider tunable filter, first and first to inputs j or power cells and swarm of memory blocks, switchboard, not forcibly connected amplifiers, exciter, vioro sensor, second band-passable filter, quadratic VTPK-torus, integrator, comparison unit sc 35 the transferred filter, through the second key of the first group to the second input of the adder, the output of which through the keys of the fourth group of the switch is connected to the inputs of the recording of memory blocks. 0 five 0 five the second input of which is connected to a spectrum detector, as well as an adjustable amplifier, the input of which is connected to the output of the second band-pass filter, and a control input to the output of the comparator unit, an adder, whose first input is connected to the output of the adjustable amplifier, synchronization unit, whose outputs connected respectively to the control inputs of the first band of a new tunable filter, a switch, a second band tunable filter, and a spectrum setter, characterized in that, with a simplified workshop It contains a tunable fence filter connected by an output to the second input of the adder, and a control input is connected to the corresponding output of the synchronization unit, through the first key of the first switch key group connected to the input of the power amplifier, each of the memory blocks made single-channel, and the outputs of the blocks of pat through the keys of the second and third grooves -. switch connect transferable rejection filter, h through the second key of the first group to the second input of the adder, the output of which through the keys of the fourth group of the switch is connected to the inputs of the memory block recording.