JPH0145586B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal processing device that accurately extracts only the characteristic components of periodic repeating signals generated simultaneously due to periodic mechanical movements of a plurality of measurement objects.

Repetitive signals of the same period generated simultaneously by periodic mechanical motions such as rotational motion and reciprocating motion of a plurality of measurement objects such as gear devices include random noise components as well as the characteristic components of the periodic motions. For example, it is desirable to quickly and accurately grasp the state of each measurement object by comparing the unique components of repeated signals generated by the rotational movements of multiple measurement objects and determining whether each measurement object is normal or abnormal. It is rare.

This invention has been made with the above points in mind, and will now be described in detail with reference to drawings showing one embodiment thereof.

1a is from the measurement target of the first channel to Fig. 2a
1b is the first signal detector to which the periodic repeating signal is input, and 1b is the first signal detector to which the periodic repeating signal is input from the measurement target of the second channel, as shown in FIG. It is a two-signal detector.

Then, the repeated signals of each channel are converted into voltage signals by both signal detectors 1a and 1b, and the outputs of both signal detectors 1a and 1b are transmitted to the first and second filters of variable cut-off frequency type, which are bandpass filters. The signal components are input to each of the band filters 2a and 2b, and only signal components in a predetermined frequency range set by the cutoff frequency of each band filter 2a and 2b are extracted, and the output of each band filter 2a and 2b is the first and second envelope. The signal is input to each of the line detectors 3a and 3b, and only the peak component of the output of each band filter 2a and 2b is extracted, and the output of both envelope detectors 3a and 3b is input to the multiplexer 4.

On the other hand, the period of the repeated signal is detected by the period detector 5, and the period detector 5 generates a trigger pulse at the beginning of each period of the repeated signal, as shown in FIG. is input to the microcomputer 6 as a timing control signal. Furthermore, by operating the operation panel 7,
The sampling period of the repetitive signal output from the multiplexer 4 is set in advance as a unit time interval T, and a sampling period setting signal is inputted from the operation panel 7 to the microcomputer 6.
Note that the cutoff frequencies of each band filter 2a, 2b and each envelope detector 3a, 3b are set by the microcomputer 6 so as to fall within a frequency range effective for extracting the eigencomponent.

Then, the repeated signals of each channel are outputted alternately from the multiplexer 4 at time intervals T by reversing the output order every cycle, and the output timings are t1, t2, ... t6, t1 in Fig. 2c. ′ time, t2′ time,
…, at t1″, at t2″, and so on.

Also, the sample-and-hold circuit 8 has a time interval T
As shown in d of the same figure, the repeated signal of the first channel inputted to the first signal detector 1a by repeating sample and hold at t1, t3, t5... is sampled at an interval of 2T time, and in one period of N+1, the Nth 1
At time t2', which is T time behind the start of period sampling,
It is sampled at 2T time intervals at t4', t6', etc., and in the N+1st period, 2T at t1'', t3'', t5'', etc. is sampled in the N+1 period. As shown in FIG.
Samples are taken at time intervals of 2T at time t4, time t6, etc., and during the N+1st cycle, at time t1', which is T time earlier than the start of sampling for the Nth cycle,
It is sampled at 2T time intervals at t3', t5', etc., and in the N+2 period, 2T at t2'', t4'', t6'', etc. is sampled in the N+2 period. It is sampled at time intervals.In addition, at t1, t1′,
Time t1'' indicates the start time of each cycle of the repeated signal.

Therefore, the outputs of the signal detectors 1a and 1b are sampled alternately at the same sampling interval, and the output of the sample-and-hold circuit 8 is converted into a digital signal by the A/D converter 9 and input to the microcomputer 6. , digital signals after the same time has elapsed from the sampling start time of each period in each channel, for example, at t1, t1′,
The digital signal at time t1'' is stored in a predetermined memory area of the microcomputer 6, and the average of the stored digital signals in each predetermined memory area for each channel is determined.

By increasing the period of the repetitive signal, the repetitive signal of each channel is sampled at T time intervals, and the outputs of each channel are superimposed and averaged, so that irregular noise components of the repetitive signal of each channel are generated. are removed, and the microcomputer 6 simultaneously outputs to the output device 10 a signal having only the characteristic component resulting from the superimposed average of the repeated signals for each channel.

Further, the outputs of the signal detectors 1a and 1b are respectively input to the square circuits 11a and 11b, and the repeated signals of each channel squared by the signal detectors 1a and 1b are sent to the multiplexer 4, the sample/hold circuit 8, The signal is inputted to the microcomputer 6 via the A/D converter 9, and all frequency components including the characteristic components and irregular noise components of each repetition signal are root-mean-squared to obtain the so-called power of all frequencies. Furthermore, the power of only the unique component of the repeated signal in each channel is determined from the output signal from the microcomputer 6 to the output device 10.

Therefore, according to the embodiment, it is possible to accurately extract the eigencomponents of the repeated signals of each channel that occur simultaneously, and it is also possible to obtain the power of all frequency components and the power of the eigencomponents of each channel. For example, abnormal states of each measurement target can be detected quickly and accurately.

Note that in the above embodiment, the number of measurement targets is two, but it is easy to increase the number of measurement targets.

As described above, the present invention includes a plurality of signal detectors into which repetitive signals of the same period of each channel generated simultaneously due to periodic mechanical motion of a plurality of measurement objects are input, and an output of each of the signal detectors. a plurality of variable cutoff frequency bandpass filters that pass only signal components in a predetermined frequency range; a plurality of envelope detectors into which the output of each of the bandpass filters is input; and a plurality of envelope detectors of each of the envelope detectors. a multiplexer that switches and outputs the output at each unit time interval for each period of the repeated signal; a sample-and-hold circuit that samples and holds the output of the multiplexer at the unit time interval; and a hold output of the sample-and-hold circuit. an A/D converter that outputs a digital signal; a period detector that detects the period of the repetitive signal; and a period detector that sets a cutoff frequency of each of the band filters and controls the timing of the detection signal of the period detector to detect the period of the repetitive signal. The present invention provides a signal processing device comprising a computer that superimposes and averages signals for each channel and extracts the characteristic component of the repeated signal of each channel.

Therefore, the sequential sample and hold of the periodically repeated signals of each channel occurring simultaneously is repeated for each period of the repeated signal, and the resulting digital signals are superimposed and averaged for each channel. Irregular noise components are removed from the repeated signals, and unique components of the repeated signals of each channel are simultaneously extracted.

Therefore, it is possible to quickly and accurately extract the characteristic components of each periodic signal that occurs simultaneously in the mechanical motion of multiple objects to be measured, such as gear devices. The state of the object can be grasped quickly and accurately.

[Brief explanation of drawings]

The drawings show one embodiment of the signal processing device of the present invention, in which FIG. 1 is a block diagram, FIG. 2 a and b are waveform diagrams of repeated signals of each channel, and FIG. 1, d and e are explanatory diagrams of sampling timing for each channel. 1a, 1b...first and second signal detectors, 2a,
2b...first and second band filters, 3a, 3b...
...First and second envelope detectors, 4...Multiplexer, 5...Period detector, 6...Microcomputer, 8...Sample and hold circuit, 9...
A/D converter.

Claims (1)

[Claims] 1. A plurality of signal detectors into which repeated signals of the same period of each channel generated simultaneously by periodic mechanical motion of a plurality of measurement objects are input, and a predetermined output of each of the signal detectors. a plurality of variable-cutoff frequency bandpass filters that pass only signal components in a frequency range of; a plurality of envelope detectors into which the outputs of each of the bandpass filters are input; and an output of each of the envelope detectors. a multiplexer that switches and outputs the output at each unit time interval for each cycle of the repeated signal; a sample-and-hold circuit that samples and holds the output of the multiplexer at the unit time interval; and a digital hold output of the sample-and-hold circuit. an A/D converter that outputs a signal; a period detector that detects the period of the repeated signal; and a period detector that sets the cutoff frequency of each of the band filters and controls the timing of the detection signal of the period detector to detect the digital signal. A signal processing device comprising: a computer that superimposes and averages each channel, and extracts the characteristic component of the repeated signal of each channel.