SU540253A1 - Method for measuring time intervals - Google Patents

Description

one

The invention relates to a measurement technique and can be used in the measurement of time intervals.

Methods are known for measuring time intervals between two pulse signals based on fixing the temporal position of certain special points of pulse fronts, for example, fixing the moments of intersection with signals of predetermined voltage levels and then measuring the time interval between the fixed moments 2.

In particular, a method is known for measuring time intervals bounded by standard pulses, the formation time of which is determined on the basis of fixing the temporal position of a number of certain points of pulse fronts between which time interval 1 is measured.

This method is characterized by a low measurement accuracy with a change in the large input signal in shape and amplitude.

The purpose of the invention is to improve the measurement accuracy with varying pulse shape and amplitude.

To do this, according to the proposed method, the ratio of the instantaneous values of the pulses at a number of points of its, {) onts, taken at a given time distance from each other, is compared, the measured values are compared with the specified ones, and the specified ratios can be specified, The measuring points, for which the measured values are equal to the specified with a certain degree of accuracy, form standard impulses whose temporal position corresponds to these measuring points.

The measurement of the proposed method is carried out in the following sequence.

Measured by the ratio of the instantaneous values of the signal at a number of points of the pulse front and the measured values are compared with the required ones. With a given interval between measuring points taken at the pulse front, the ratio of the instantaneous values of the signal at these points uniquely determines the temporal position of the pulse front, since it characterizes its shape and position on the time axis.

If the specified and measured values are equal, standard impulses are formed, whose temporal position corresponds to the time interval between the measured impulses, and this time interval is measured.

FIG. 1 shows a block diagram of a device implementing the proposed measurement method; in fig. 2 is a diagram of the implementation of the unit for measuring the ratio of the instantaneous values of the signal at dimensional points.

The device contains a source of signals 1, a block 2 measuring the ratio of the instantaneous values of the signal, a block forming reference pulses 3, a control block 4, a time interval meter 5, a binary quantizer 6, a switch 7, accumulators 8, an analysis stop node 9.

All units of the device can be implemented on the basis of known nodes on the elements of digital technology. The unit for measuring the instantaneous value of the signal may be, for example, based on digital accumulation analyzers of the mixture "signal under test + reference signal; the unit 3 of the formation of the reference pulses, determined by us, their temporary position of the controlled points, is implemented on the basis of frequency dividers, given its generator and decoder; control unit 4 is implemented on elements of digital technology in the form of logic circuits and memory elements, for example, in the form of flip-flops; the time interval measurement unit 5 is implemented on the basis of any known time interval meter.

The measured signals come from block 1 to the input of block 2, the second inputs of block 2 are supplied with strobe signals, the temporal position of which determines the temporary polarization of the measuring points, the measurement results of the ratio of the instantaneous values of the signal at measuring points are received in block 4 of control and analysis of data where the measurement results are compared with a predetermined number of numbers, and according to the comparison results, a control signal is generated for correcting the time position of the gating, their pulses, after the measured ratios obtained coincide with the set with the required degree of accuracy, from block 4 a resolution signal is issued for measurement by block 5 of the time interval between the gates, with their pulses corresponding to the same points of the front of the first and second pulses, limited by their time interval.

An example of one of the possible implementations of block 2 is shown in FIG. 2

Here, the incoming mixture of signal and noise is quantized by the binary quantizer 6. The quantized samples are distributed by switch 7 to accumulators 8, the number of which is determined by the number of control points. When one of the drives is full

8, the analysis stop node 9 generates a signal for termination of accumulation and permits unit 4 to analyze 8 ratios of measured points obtained in accumulators 8.

The proposed method can be used with an unknown form of pulses, limiting the time interval. In this case, the ratios of the instantaneous values in the dimensional points of the front for one of the pulses that limit the time interval are measured. In this case, the ratios of the instantaneous values are measured at the frontal dimensional points for one of the pulses organizing the time interval, and the measured ratios are taken as given for the second pulse, limiting the time interval. In this case, the initial required values of the ratios are not known, they are determined during the measurement process. It should be emphasized that the more the number of instantaneous ratios is used to characterize the pulse fronts, the more fully its shape is set, therefore the more complex the shape of the pulse can be correctly recognized and reduced to a time scale.

Claims (2)

1.Avt. swith USSR № 429404, M. Kl.2 G 04F 10/04, 02.11.72 (prototype). 2.Mit B.N. seam, "Determination of the temporal position of pulses in the presence of interference, M., Sov. Radio, 1962, p. 49. R From 5klok 3 71 (rig 2