RU2464612C1 - Method for recirculation-nonius time-to-digital conversion - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: method for recirculation-nonius time-to-digital conversion is based on recirculating start and stop pulses which represent the beginning and end of a converted time interval in corresponding start and stop recirculators with recirculation period T_st of the start pulse and recirculation period T_sp=T_st-τ of the stop pulse, where τ is the conversion sampling rate, and counting the number of recirculations of the stop pulse from the time of its input into the stop recirculator to the time when the recirculating start and stop pulses match, wherein in each of the recirculations, duration of the start pulse is increased by the value of the conversion sampling rate and duration of the stop pulses remains the same.

EFFECT: faster conversion.

Description

The invention relates to information-measuring equipment and can be used to convert single time intervals of nanosecond duration to a digital code in radar and radio navigation systems, including the global navigation satellite system (GLONASS).

A known method of converting a time interval (TI) specified by start and stop pulses corresponding to the beginning and end of the converted TI, in which the start pulse is subjected to a multi-channel time shift with a shift resolution τ equal to the step resolution, and then fix the coincidence shifted in time start pulses with a stop pulse and the number of recorded matches determine the digital conversion result [1].

The disadvantage of this method is the large amount of hardware costs, significantly increasing with increasing conversion accuracy or increasing the time range of the converted VI.

A method is known (prototype) converting the time interval based on recirculations start and stop pulses representing the beginning and the end of the converted time interval corresponding start and stop recirculator with recirculation period _Tg start pulse and the period T recirculation _cn = T _st -τ of the stop pulse (where τ is the discreteness of the conversion), and the calculation of the number of recirculations of the stop pulse from the time it was entered into the stop recirculator until the time of coincidence of the recirculating start and stop pulses [2].

The disadvantage of the prototype method is the low speed of conversion.

The purpose of the proposed method of recirculation-nonius conversion of time - code is to increase the speed of conversion.

The goal is achieved in that the start and stop pulses corresponding to the beginning and end of transformed VI is subjected to recirculation in their respective start and stop recirculator with recirculation period _Tg start pulse and the period T _cn recirculation _Tg = -τ stop -pulse, where τ is the discreteness of the conversion, and counting the number of stop-pulse recirculations from the time it was introduced into the stop-recirculator and until the recirculating start and stop pulses coincide, and in each of the recirculations, the duration of the start pulse is extended by the beginning of the discreteness of the conversion, and the duration of the stop pulses is left unchanged.

The essence of the proposed method of recirculation-nonius conversion of time - code is as follows.

Start and stop pulses are calibrated initial duration t _v and t _cn corresponding to the beginning and end of transformed WI duration t _x is recycled in their respective start and stop recirculator with recirculation period _Tg start pulse and the period T recirculation _cn = T _st -τ stop pulse. Pulse sequences generated during recirculation are represented by expressions, respectively:

start recirculator

where the second term n _st τ represents the result of expanding t _st on the discrete value of the transformation τ in each of n _st start-pulse recirculations,

and stop recirculator

where n _sp - the number of recirculations of the stop pulse.

The moment of coincidence of the recirculating start and stop pulses corresponds to the equality

Where does the duration of the converted VI come from?

.

.

As

and T _st -T _SP = τ and, providing

define

The conversion time of the proposed method

The algebraic operation of obtaining the value of 2n _{cn is} carried out by adding the least significant bit with the value of the bit “logical 0” to the calculated digital value n _cn .

In the case of the prototype method, the conversion time is described by the expression

From comparing (7) and (8), the conversion speed of the proposed method is doubled. Thus, the objective of the invention is achieved.

Literature

1. A.K. Kovtun, A.N. Shkuro. Principles of constructing digital time interval meters (review). Instruments and experimental equipment, No. 1, 1973, p. 8, Fig. 2.

2. A.K. Kovtun, A.N. Shkuro. Principles of constructing digital time interval meters (review). Instruments and experimental equipment, No. 1, 1973, p. 9, Fig. 3.

Claims (1)

A method of recirculating-vernier conversion time - code based on recirculation start and stop pulses representing the beginning and the end of the converted time interval corresponding start and stop recirculator with recirculation period _Tg start pulse and the period T recirculation _cn = T _st -τ stop pulse, where τ is the discreteness of the conversion, and counting the number of recirculations of the stop pulse from the time it was entered into the stop-recirculator until the time of coincidence of the recirculating start and stop pulses, characterized in that, in order to increasing the speed of conversion, in each of the recirculations the duration of the start pulse is expanded by the value of the discreteness of the conversion, and the duration of the stop pulses is left unchanged.