SU1709233A1 - Digital phase meter of medium shift of phases between signals with known frequency shift - Google Patents

Abstract

The invention can be used in radionavigation systems for measuring the average phase between the reference and fluctuating measurement signals with a known frequency shift, in particular when measuring the angular positions of an object. The purpose of the invention is to expand the field of application by providing a measurement of the average value of the phase shift between the reference and fluctuating measurement signals with a known frequency shift and expanding the range of the measured phase shifts. The digital phase meter contains drivers 1 and 2, an element OR 3. triggers 4.5.9 and 10, elements AND 6.7.11 and 12, a reversible counter 8, dividers 14 and 13 frequencies and a counter 15 of the number of averages. 2 or VI. ToGJ SL > &

Description

The invention relates to a measurement technique and can be used in radio navigation systems for measuring the average phase value between a reference and fluctuating measurement signals with a known frequency shift, in particular for angular measurements of the position of a moving object.

The difference in frequencies between the reference and y, measurement signals may be due, for example, to the presence of a frequency Doppler shift, the magnitude of which within the measured interval is known and varies little.

A device is known which permits the measurement of an optimal phase shift between a reference fluctuating measurement signal with a frequency shift. In this device, using complex arithmetic units, separate processing of the reference measurement signal is performed, and the measurement results are processed by a complex calculation algorithm.

A phase-to-code converter is known that contains two amplifiers, a limiter, two switches, two pulse formers, a trigger for converting the phase difference into a time interval, seven AND elements, three delay elements, three OR elements, three triggers, and a time setting unit for the pulse generator.

8 this device; ae the phase difference of the output signals is converted E the time interval that is quantized in time m is formed into a code by a pulse counter, while the number of pulses arriving at the input of the counter is proportional to phase A -i-360

This device measures the phase shift between signals of the same frequency during phase s fluctuations within ± 180 °.

However, this device cannot work with input measurement signals that have a frequency shift, since in this case the additional phase shift between them over a measured time interval may exceed several per-one reference signal, which is not provided in the well-known device.

The closest in technical essence to the present invention is a device comprising the first and second pulse formers, the first ii second trigger, the first and second elements AND, the OR element and the reversible counter b4mpulCO8. the inputs of which are soy, diienes with the outputs of the elements I, the first inputs of the n-terminals are connected respectively to the inverse and direct outputs of the first trigger, the second inputs of the elements And are connected to the terminal of the calibrated time interval, and the third to the terminal of the generator

counting pulses, while the output of the first pulse generator is connected to the first input of the first trigger, the inputs of the OR element are connected to the output of the first and second pulse formers, and its

0 output - with the input of the second trigger, the output of which is connected to the fourth inputs of both elements AND, while the output of the second pulse generator is connected to the second input of the first trigger.

5 In this device, by averaging the measurement results, the measurement accuracy of the phase shift during phase fluctuations near the zero phase shift is improved, but, like in the second analog,

0 provides a phase shift measurement in the presence of a frequency shift in the measurement signal.

The purpose of the invention is to expand the field of application by providing a measurement of the average value of the phase shift between signals with a known frequency shift Y: an extension of the range of measured phase shifts.

This goal is achieved by the fact that

0 digital phase meter containing the first and second pulse formers of input C5 gnals, the OR element, the first and second triggers, the first and second elements AND and the reversible pulse counter, the inputs of which are connected to the outputs of the elements AND, the first inputs of the last connected to the inverse, etc. the outputs of the first trigger, the second input of the first element And is connected to the direct

0 output of the second trigger, and the third inputs of the elements And connected to the terminal of the generator of the reference signal, entered the third and fourth triggers, the third and fourth elements And two frequency divider (2P + 1)

5 input signals, where P 1,2,3 - number

the periods of shift between the reference and measuring signals of a divided frequency, and the counter of the number of averages, the output of the first pulse generator is connected to the first input of the third element I, the output of which is connected to the counting input of the frequency divider of the reference signal, the first output of which is connected to the zero set input of the first trigger and with

5 with a single installation input of the fourth trigger, the output of which is connected to the second input of the fourth element I, the first input of which is connected to the output of the second pulse shaper, and its output is connected to the counting input of the frequency divider

measuring signal, the output of which is connected to the zero setting input of the second trigger, the single setting input of which is connected to the single setting input of the first trigger and to the output of the OR element, the first input of which is connected to the second output of the reference signal frequency divider and to the input of the averaging number counter, the output of which connected to the zero setup inputs of the third and fourth triggers, and the second input of the OR element is connected to the reset inputs of the frequency divider of the reference signal, reversible count pulse meter, averaging number counter, with single installation inputs of all bits of the frequency divider of the measuring signal and with the Start signal terminal.

Fig, 1 shows a block diagram of the device; 2, time diagrams of the device operation.

Digital phase meter average phase shift between signals with a known frequency shift contains the first and second drivers 1 and 2 and pulses, the element OR 3, the first and second triggers 4 and 5, the first and second elements 1/1 6 and 7, the reversible counter 8 pulses, inputs which are connected to the outputs of the first and second elements And b and 7, the first inputs of the latter are connected respectively to the inverse and direct outputs of the first trigger 4, the second input of the first element And 6 is connected to the forward output of the second trigger 5, and the third inputs of the elements And 6 and 7 are connected the reference signal generator terminal, the third and fourth triggers 9 and 10, the third and fourth elements 11 and 12, the divider 13 of the reference signal frequency, the divider 14 of the measuring signal frequency and the counter 15 of the number of averages, the output of the first driver 1 pulses connected to the first the input of the third element 11, the output of which is connected to the counting input of the divider 13 of the frequency of the reference signal, the first output of which is connected to the zero setting input of the first trigger 4 and to the single setting input of the fourth trigger 10, the output to second connected to the second input of the fourth element And 12, the first input of which is connected to the output of the second pulse shaper 2, and its output is connected to the counting input of the frequency divider 14 of the measuring signal, the output of which is connected to the zero setting input of the second trigger 5, the single setting input of which is connected with a single installation input of the first trigger 4 and with the output of the element OR 3, the first input of which is connected to the second output of the divider 13 of the reference signal frequency and to the input of the counter 15 of the number of averages, output which is connected to the mounting zero inputs of the third and fourth flip-flops 9 and 10. A second input of OR gate 3 is connected to the reset input of divider 13 frequency reference signal, a reversible counter 8 pulses,

0 counter 15 the number of averages, as well as with a single installation input of the third trigger 9 and with a single installation input of all bits of the divider 14 of the measuring signal frequency and with the signal5 terminal,

The device works as follows.

The input reference signal using the first driver 1 pulses, tr.et0 its element And 11 and the divider 13 of the frequency of the reference signal is converted into a pulse sequence divided by (2P + 1) times the frequency, where P is the number of periods of shift between the reference and measuring

5 signals divided frequency. Similarly, the measuring input signal is converted into a pulse sequence also divided by (2P + 1) times the frequency, but shifted by periods of the input reference signal relative to the pulse sequence of the reference frequency signal .

5 During the measuring time interval, a multiple (2P + 1) periods of the reference signal, generated by the counter 15 of the averaging number, time shifts are formed between the pulses of the reference and measuring signals divided by (2P + 1) times the frequency, subtraction from each formed time interval the shift of the reference time interval equal to the P periods

5 input reference signal, and quantization of the resulting difference time intervals by the reference frequency signal.

The process of measuring the average phase shift begins with the arrival of the signal.

0 (Fig. 2a) setting the device to its initial state, in which the frequency divider 13, the averaging number counter 15 and the reversible pulse counter 8 are set to the zero state, and the divider 14

5, the frequencies of the measurement signal and the third trigger 9 are set to one. In addition, the Start signal, passing through the OR 3 element, sets the first and second triggers 4 and 5 to a single state, forming at their outputs the beginning

respectively subtractive and measuring time intervals (Fig. 2e, and, time ti).

After that, through the open third element 11, the counting input of the divider 13 of the reference signal receives reference pulses from the output of the first generator t of pulses (Fig. 2b) and after counting P of pulses, a pulse is formed at its first output (Fig. 2d), which sets the first trigger 4 to the zero state, forming at its output the end of the subtracting time interval (fig. 2e, moment t), and into the single state the fourth trigger 10 which opens the fourth element 12 passing the measurement pulses through it (fig 2h) to form ovannyh second pulse generator 2.

The first measuring pulse (fig. 2z) from the output of the element 12 after passing through the divider 14 of the frequency of the measuring signal sets the second trigger 5 to the zero state, forming at its output the end of the measuring time interval (fig. 2i, time t2).

After the subtractive time interval is formed using the first and second triggers 4 and 5 and the first and second elements 6 and 7 functionally associated with them, a difference time interval is created (Fig. 2k), different differences between the measuring and subtracting time intervals, which is time-quantized by a reference frequency signal supplied to the third inputs of these elements AND 6 and 7,

The first two inputs of the first element And b receive voltages generated at the inverse output of the first trigger 4 and the forward output of the second trigger 5, respectively, and the first two inputs of the second element And 7 receive the voltages formed at the direct output of the first trigger 4 and inverse output of the second trigger 5.

In this case, at the outputs of the first and second elements And 6 and 7, pulse packets of the reference frequency are formed, which are proportional to the difference time intervals, and at the output of the first element And 6, a pulse packet is formed (Fig. 2k) with a positive value of the difference time interval, i.e. when the measuring pulse is delayed relative to the corresponding reference pulse, and at the output of the second element I 7, a packet of pulses is formed (Fig.2l) ahead of the measuring pulse.

Formed packets of pulses from the output of the first or second elements And 6 and 7, respectively, are fed to the summing or subtracting inputs of the reversing

pulse counter 8, in which the number of input pulses is accumulated.

With the arrival of the start signal, a subtractive time interval is formed at the output of the first trigger 4, equal to the time shift between the start signal (Fig. 2e. Moment) and the first reference pulse (time ti). Similarly, a measuring time interval is formed between the Start signal and the first measuring pulse (Fig. 2i. Moment ta).

Subsequent formation of subtraction and measurement time intervals will be performed every

0 (2P + 1) periods of the reference signal. In this case, the beginning of the subtractive time interval is formed at the time of the appearance of a pulse at the first output of the frequency divider 13, and the end of this time interval is formed at the time of the appearance of the pulse at the second output of this frequency divider. Similarly, at the moment of appearance of a pulse, the beginning of the measuring time interval is formed at the first output of the first frequency divider 13, the end of which is formed at the time of the appearance of a pulse at the output of the second frequency divider 14.

After counting m reference pulses

5 signals divided by (2P + 1) times the frequency at the output of the counter 15, the number of averages will form a pulse (Fig.2m), which will set the third and fourth triggers 9 and 10 to the zero state and prohibit the output pulses of the first and second drivers 1 and 2 pulses through the third and fourth elements And 11 and 12 to the inputs of the first and second dividers 13 and 14 frequency. At this time, the measurement cycle is terminated.

5 until the next occurrence of the Start signal, the follow-up period of which should exceed m (2P + 1) periods of the reference signal.

As a result, the oversized time interval in the reversible counter of 8 pulses will accumulate the number N. equal to the sum of the two terms NI and N2. moreover, the first term NI is proportional to the magnitude of the average phase, and the second term N2 - the value

Claims (1)

5 additional phase shift due to the presence of a frequency shift between the input signals, which at a constant frequency shift has a constant value and can be determined from the expression (1) m (m - 1) Ti-TO 2 m (m - 1) C -frr) fofaV) where m is the number of averages; K (2P + 1) is the frequency division factor; Ti, fn is the period and frequency of the measuring signal; That, fo is the period and frequency of the reference signal; Te, fa period and frequency of the reference signal. The average phase shift is determined from the expression (2) where lit-T- is the sampling interval, measured in radians. The maximum allowable frequency shift D f depends on the number of averages m and the measurement interval and can be determined from the expression (3) L. about f. fo n f o, 4 -, (3) Af. and 2 P +1 K t K In this case, the measurement interval should exceed m (2P + .1) periods of the reference signal. The device can be implemented on typical microcircuits, for example, on microcircuits, for example, on microcircuits of the 133,533 series: formers of 1 and 2 pulses on the microcircuit 533ТЛ2; the element OR 3 - on a 533 LAZ chip; triggers 4, 5, 9, and 10 on the 533TM2 microcircuit; elements 1/1 6, 7 and .11, 12 - on the 533 LAZ microcircuit; reversible counter 8 - on the chip 133IE7; dividers 13 and 14 frequencies - on chip 133IR1, used in the ring shift register mode; counter 15 of the number of averages - on the chip 133IE7. Measurement of the average phase shift between signals with a frequency shift is one of the main operations in phase systems when determining the angular position of a moving object. The proposed device, using simple technical means and operations, makes it possible to measure the average phase shift between signals with a frequency shift, while ensuring high accuracy and reliability of measurements. The instrumental error of the device, determined by the ratio of the frequencies of the reference and reference signals, when using modern high-frequency elements (microcircuits) can be negligible compared to the fluctuation error, which in the proposed device decreases by Vm times. In addition, by eliminating the coincidence of the reference and measurement signals, the device ensures the reliability of measurements when the impulses of the reference and measurement signals coincide. The proposed device can be used to visually monitor the average phase shift. To do this, it is necessary to subtract the result from the contents of the reversible counter 8 to the known calculated number Na m and divide the result by the number of averages. In this case, the Start signal in the reversible counter 8 introduces an additional number of 2-1-N2, where P is the number of bits of the reversible counter, and to ensure a simple division process, the number of averages is 2, where M is an integer and the measurement result , starting with (M + 1} th bit of a reversible counter. Claim of the invention Digital phase meter for average phase shift between signals with known frequency shift, containing first and second pulse shapers, OR element, first and second triggers, first and second elements And And reversible pulse counter, the inputs of which are connected respectively to the outputs of the elements And, the first inputs of the latter are connected respectively to the inverse and direct outputs of the first trigger, the second input of the first element And is connected to the forward output of the second trigger and the second input of the second element And is connected to the terminal of the generator of the reference signal, while the inputs of the first and second pulse formers are connected to the terminals of the reference and measuring input signals, respectively different in that, in order to expand the scope of application by providing a measurement of the average value of the phase shift between signals with a known frequency shift and expanding the range of measured phase shifts, the third and fourth triggers, the third and fourth And elements, and two frequency splitters ( 2P + 1), where P 1,2,3 is the number of periods of shift between the reference and measuring signals of the divided frequency, and the counter of the number of averages, while the third input of the second element I is connected to the inverse output of the second trigger, the output of the first ф The pulse driver is connected to the first input of the third element I, the output of which is connected to the counting input of the first frequency divider, the first output of which is connected to the zero setting input of the first trigger and to the single installation input of the fourth trigger, the output of which is connected to the first input of the fourth element I, the second input which is connected to the output of the second pulse generator, and its output is connected to the counting input of the second frequency divider, the output of which is connected to the zero setting input of the second tr ggera, the installation unit whose input is connected with the mounting unit and the input of the first flip-flop with the output of the OR gate, a first input coupled to the second output of the first frequency divider and to the input of counter averaging, the output of which is connected to the zero setup inputs of the third and fourth triggers, and the second input of the OR element is connected to the reset inputs of the first signal frequency divider, reversible pulse counter, averaging number counter, with a single installation input of the third trigger, with a single installation input of all bits of the second frequency divider and with the Start signal terminal, while the second input of the third element I is connected to the output of the third trigger. Phage. 2