RU2634305C1 - Method to determine mutual location of mobile objects in full-communication radio network - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: method to determine the mutual location is based on the fact that request signals are generated on each object, propagation delay of radio signals and values of correlation responses corresponding to these measurements within each pair of objects are measured, at the end of the frame of full-communication exchange of the measured information on each object the mutual distances between all objects are calculated by using the delays measured at the highest value of autocorrelation responses, mutual velocities and accelerations are calculated.

EFFECT: increased noise immunity, accuracy in full-communication radio networks due to systems of calculation of mutual velocities and accelerations.

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Description

The invention relates to radio engineering and can be used in radio navigation and communication systems to determine the relative position of moving objects (PO).

A known method for determining the relative location of moving objects [1], using a common request signal to all moving objects, and response signals generated by each software after a certain period of time. Three satellites, spaced in space, relay the interrogation signals to the ground station, which identifies the software and determines their location.

The main disadvantages of this method are:

- information about the location of the software is present only at the ground station;

- the satellite infrastructure is used to determine the location, therefore this system is not autonomous.

There are also known methods for determining the relative position of moving objects, which are used in collision avoidance systems and air traffic control [2].

The main disadvantages of these methods are:

- location is carried out only between two software;

- all flight parameters of each software are carried out by their own measuring systems of each software.

The closest analogue, selected as a prototype, is a method for determining the relative location of n objects [3], which consists in the fact that they generate request signals at the time of receiving response signals at the i-th object, and the addressee of the (i + 1) -th object is assigned a sign of the transfer to this object of the initiative to form the next request-response signal, the next after the nth being the first object, and when the request-response and response signals arrive at the ith object, the direction of arrival of all the signal is measured on it s and, in addition, upon receipt of request-response and response signals on the ith object, the delay between the signal currently received at the time encoded by the ranging code and the eigen signal encoded by the ranging sensor is measured, and the eigen signal is synchronized with the received signal from the total number of delays transmitted during the information exchange between objects, allocate numerical values of similar delays, measured and calculated at other objects, according to the delays measured at this object those accepted from other objects, calculate the distance to other objects according to the formula:

- номер обмена в группе соответствует началу информационного обмена в группе;Where

- the exchange number in the group corresponds to the beginning of the information exchange in the group;

i is the number of the object on which the propagation delay of the signal and, accordingly, the range are calculated;

j is the number of the object that is in transmission in the t-th time interval of the exchange time, and j simultaneously satisfies the following conditions:

k is a coefficient satisfying the condition:

k is an integer;

n is the number of objects in the group;

C is the signal propagation speed;

- дальность между i-м и j-м объектами, измеренная на i-м объекте в t-й интервал времени в группе;

- the distance between the i-th and j-th objects, measured on the i-th object in the t-th time interval in the group;

- временная задержка между собственным опорным сигналом, закодированным дальномерным кодом j-го объекта, и принимаемым j-м объектом сигналом, закодированным таким же дальномерным кодом, в t-й интервал информационного обмена в группе;

- the time delay between the own reference signal encoded by the ranging code of the j-th object and the signal received by the j-th object encoded by the same ranging code into the tth interval of information exchange in the group;

- коэффициенты, определяемые выражением:

- coefficients defined by the expression:

b is the number of the exchange interval satisfying the condition:

τ _{i, j} is the propagation delay of the signal between the i-th and j-th objects in the b-th exchange interval in the group, the measured and calculated delays are reported to other objects.

The main disadvantages of the prototype are:

- low noise immunity;

- the inability to carry out simultaneous pair exchange;

- accumulation of errors in measuring mutual distances over time;

- lack of calculation of mutual speeds and accelerations.

The objective of the invention is to increase the noise immunity, survivability, accuracy and expansion of functionality in fully connected radio networks.

The indicated technical result is achieved by generating query signals at the time of receiving response signals at the i-th object, characterized in that during the time window the pair of objects performs simultaneous duplex exchange of range-finding codes and the measured values of autocorrelation responses of their own matched filters, measure double mutual propagation delays at each object, exchange the values of the autocorrelation responses of the matched filters received for each pa exchange, compute the values of the autocorrelation responses of the matched filters at each object, select the double propagation delays of the radio signals between the objects corresponding to the largest values of the autocorrelation responses of the matched filters, calculate the mutual ranges at the end of the frame, consisting of (N-1) time windows, where N is the number objects, using the selected propagation delays, and mutual deletions are calculated by the formula:

- взаимная дальность между i и j ПО, измеренная в Tn временное окно;Where

- mutual distance between i and j software measured in Tn time window;

- двойная задержка распространения радиосигналов между i и j ПО, измеренная в Tn временное окно;

- double propagation delay of radio signals between i and j software, measured in Tn time window;

C is the propagation speed of radio signals,

mutual speeds are calculated by the formula:

- взаимная скорость между i и j объектами, вычисленная в (К+1) кадре;Where

- mutual velocity between i and j objects calculated in the (K + 1) frame;

- взаимная дальность между i и j объектами в К кадре;

- mutual distance between i and j objects in the K frame;

- взаимная дальность между i и j объектами в (К+1) кадре;

- mutual distance between i and j objects in the (K + 1) frame;

T _{K + 1} - frame start time (K + 1);

T _K - frame start time K;

mutual accelerations are calculated by the formula:

- взаимные ускорения между i и j объектами в (К+1) кадре;Where

- mutual accelerations between i and j objects in the (K + 1) frame;

- взаимная скорость между i и j объектами в К кадре;

- mutual velocity between i and j objects in the K frame;

- взаимная скорость между i и j объектами в (К+1) кадре;

- mutual velocity between i and j objects in the (K + 1) frame;

and at the end of each frame, the mutual offsets, velocities and accelerations between all objects are calculated, the mutual duplex pair exchange is repeated in each frame, the mutual propagation delays are measured and the mutual offsets, speeds and accelerations are calculated.

Let us consider a method for determining the relative position of moving objects in a fully connected radio network using a specific example of four software (clusters) consisting of four software.

The drawing shows a frame of a temporary exchange of rangefinder codes (DC) and information in a cluster of four software, as well as the process of calculating mutual distances, speeds and accelerations.

In the first column of the figure, four softwares are numbered from 0 to 3.

Time windows of information exchange inside the frame are indicated by T0, T1 and T2. Under the time windows, the numbers of the interacting software are indicated. In the time window T0 there is an exchange of DC and information PO0 with PO1, as well as PO2 with PO3. In the time window T1, the DC is exchanged and information PO0 with PO2, as well as PO1 with PO3. In the time window T2, the DC is exchanged and information PO0 with PO3, as well as PO1 with PO2. Below, in the form of a mimic diagram, exchanges between software are illustrated. Computations of the mutual offsets, velocities, and accelerations are given in full form for PO0, for other software they are similar and therefore are shown conditionally.

The following notation is introduced in the drawing:

Tk - frame duration;

Ti-j - double propagation delay of radio signals, measured in this time window between i and j software;

AOi is the value of the autocorrelation response measured on the i-th software in this time window;

- несущая частота передатчика и символ излучения;Fn

- carrier frequency of the transmitter and radiation symbol;

Y is a symbol denoting the reception of DC and information from the software;

- направления обмена ДК и информацией ПО.

- directions for the exchange of DCs and software information.

The column “Storage of delays and autocorrelation responses” shows the measured values of mutual delays and the values of their autocorrelation responses stored at the end of the frame.

In the column “Comparison of responses”, the quotient of the division of the stored response values is calculated, for example, the value of AO ₃ obtained by measuring the delay of the DC by PO3 is divided by the value of AO ₂ obtained by measuring the delay of the DC by PO2. If the quotient of their division is ≥1, then to calculate the mutual distances between PO2 and PO3, the delay T _3-2 is measured, measured at PO3 with a larger value of the autocorrelation response, if the quotient is less than or equal to 1, then the delay T _0-2 measured at PO2 with a larger value of the autocorrelation response (see drawing).

In the column “Calculation of mutual removals”, the formulas are used to calculate mutual removals between all software on this software:

D ^K1 _ij is the mutual distance between i and j ON calculated in the K1 frame;

3 × 10 ⁸ - the speed of propagation of radio waves.

In the column “Calculation of mutual speeds” are given the formulas with which the mutual speeds between all software on this software are calculated:

V ^K1 _ij is the mutual velocity between i and j software calculated in the K1 frame;

D ^K-1 _ij is the mutual distance between i and j software calculated in the previous K-1 frame;

Tk - frame duration.

In the column “Calculation of Mutual Accelerations” are given the formulas with which the mutual accelerations between all the software on this software are calculated:

U ^K1 _ij is the mutual acceleration between i and j software calculated in the previous K1 frame;

V ^K-1 _ij is the mutual velocity between i and j software calculated in the previous K-1 frame.

Consider the process of exchanging DC and information in the frame sequentially.

In the time window T0, a duplex exchange of the DC and its own information between PO0 and PO1 is performed. PO0 transmits at frequency F1 F1 DK PO1, and PO1 transmits at frequency F2 DK PO0. PO0 and PO1 receive DCs with a propagation delay between PO0 and PO1. After processing the DCs with matched filters and extracting autocorrelation responses by them, PO1 transmits DC at frequency F3, and PO0 transmits at DC frequency F4. PO1 and PO0 receive these DCs with double propagation delay between PO1 and PO0. After the DC processing by the matched filters and the isolation of the PO0 and PO1 autocorrelation responses by them, the double propagation delay between PO0 and PO1 and the relative values of the autocorrelation responses of their matched filters are measured.

In the time window T1, the DC PO0 with PO2 and PO1 with PO3 are duplexed in the same way. As a result, these SWs measure the double propagation delay between SW0 and SW2, as well as between SW1 and SW3. Simultaneously with the exchanges, the DC PO0 transmits the PO2 measured in the time window T0 the double propagation delay between PO0 and PO1 and the digitized value of the autocorrelation response of the DC received in the time window T0, and the PO3 transmits PO0, the double propagation delay measured in the time window T0 between PO2 and PO3 and the digitized value of the autocorrelation response of the DC taken in the time window T0.

In the time window T2, the DC PO0 with PO3 and PO1 with PO2 are duplexed in the same way. As a result, these SWs measure the double propagation delay between SW0 and SW3, as well as between SW1 and SW2. At the same time, the previously measured double propagation delays and the digitized values of the autocorrelation responses of previously received DCs are exchanged.

At the end of the K1 frame, each software has measured mutual double propagation delays between all software. Each delay corresponds to the magnitude of the autocorrelation response at which it was measured. The decision on the reliability of the delay is made according to the algorithm described on page 7 and in the figure in the column “Comparison of responses” in favor of a delay with a large autocorrelation response, in the future this delay is used in the calculations of mutual removals by the formula:

- взаимная дальность между i и j ПО, измеренная в Tn временном окне;Where

- mutual distance between i and j software measured in Tn time window;

- двойная задержка распространения радиосигналов между i и j ПО, измеренная в Tn временном окне;

- double delay of the propagation of radio signals between i and j software, measured in Tn time window;

C is the propagation speed of radio signals.

In the next frame K2 (not shown), similar operations are performed. Based on the ranges calculated in frames K1 and K2, the mutual speeds of all software are calculated by the formulas:

- взаимная скорость между i и j объектами,вычисленная в (К+1) кадре;Where

- mutual velocity between i and j objects calculated in the (K + 1) frame;

- взаимная дальность между i и j объектами в К кадре;

- mutual distance between i and j objects in the K frame;

- взаимная дальность между i и j объектами в (К+1) кадре;

- mutual distance between i and j objects in the (K + 1) frame;

T _{K + 1} - frame start time (K + 1);

T _K - the start time of the frame K.

In the next frame K3 (not shown), operations similar to those in frames K1 and K2 are performed. According to the mutual speeds calculated in frames K1 and K2, the mutual accelerations of all software are calculated by the formulas:

- взаимные ускорения между i и j объектами в (К+1) кадре;Where

- mutual accelerations between i and j objects in the (K + 1) frame;

- взаимная скорость между i и j объектами в К кадре;

- mutual velocity between i and j objects in the K frame;

- взаимная скорость между i и j объектами в (К+1) кадре.

- mutual velocity between i and j objects in the (K + 1) frame.

Thus, the technical result in terms of improving noise immunity, survivability, accuracy and expanding functionality in fully connected radio networks is provided by:

- measurement of propagation delays and values of autocorrelation responses corresponding to these measurements by each object and transmission of these values to other objects;

- receipt by each object of the measured propagation delays;

- calculating mutual distances using delays measured at maximum correlation responses;

- the use by each subscriber of reception spaced in space, frequency and time.

- calculation and storage at each object of mutual removals, speeds and accelerations between all objects, therefore, when any object disappears from the cluster, information is not destroyed.

Information sources

1. Patent US 4359733, CL G01S 13/78, published November 16, 1982

2. S.I. Bychkov, G.A. Pokholkov, V.I. Yakovlev. Radio engineering systems for preventing collisions of aircraft. M., Sov. Radio, 1977, p. 76.

3. Patent RU 2111503, cl. G01S 5/02, published 05/20/1998

Claims (18)

A method for determining the relative location of moving objects in a fully connected radio network, which consists in generating interrogation signals at the time of receiving response signals at the i-th object, characterized in that during the time window of a pair of objects, a simultaneous duplex exchange of ranging codes and measured values of autocorrelation responses is performed own matched filters, measure the double mutual propagation delays at each object, exchange autocorrelation values of the responses of the matched filters obtained during each pair exchange, the values of the autocorrelation responses of the matched filters on each object are compared, the double propagation delays of the radio signals between the objects are selected, which correspond to the largest values of the autocorrelation responses of the matched filters, the mutual ranges at the end of the frame consisting of (N-1 ) time windows, where N is the number of objects, using the selected propagation delays, and mutual deletions are calculated by the formula

Where

- mutual distance between i and j software measured in Tn time window;

- double propagation delay of radio signals between i and j software, measured in Tn time window; C is the propagation speed of radio signals, mutual speeds are calculated by the formula

Where

- mutual velocity between i and j objects calculated in the (K + 1) frame;

- mutual distance between i and j objects in the K frame;

- mutual distance between i and j objects in the (K + 1) frame; T _{K + 1} - frame start time (K + 1); T _K - frame start time K, mutual accelerations are calculated by the formula

Where

- mutual accelerations between i and j objects in the (K + 1) frame;

- mutual velocity between i and j objects in the K frame;

- mutual velocity between i and j objects in the (K + 1) frame, and at the end of each frame, the mutual offsets, velocities and accelerations between all objects are calculated, the mutual duplex pair exchange is repeated in each frame, the mutual propagation delays are measured and the mutual offsets, speeds and accelerations are calculated.

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