RU2746218C1 - Radionavigation multi-position differential distance system - Google Patents

Abstract

FIELD: radionavigation.

SUBSTANCE: invention relates to radionavigation systems for determining location or obtaining information related to location for navigation purposes by means of propagation properties of radio waves and properties of surfaces (lines) of position. The system includes of the equipment of the basic navigation post, the slave posts and the consumer. The equipment of the basic navigation post includes a device for entering the code and coordinates of the post, a modulator, a transmitter and an antenna. The equipment of the slave posts includes an antenna, a decoupling device, a radio frequency amplifier, a decoder, a device for entering the code and coordinates of the post, a modulator and a transmitter. Information consumer equipment includes antenna, receiver, decoder, RAM codes and coordinates of navigation posts. The system additionally contains a device for forming a navigation field with time division of channels, a device taking into account the total number of navigation posts.

EFFECT: technical result consists in creating a mobile radionavigation multi-position differential distance system capable of duplicating signals from global navigation systems when they are lost on limited areas of the earth's surface.

1 cl, 6 dwg

Description

The system belongs to radio-navigation multi-position differential-rangefinder systems designed to determine the coordinates of ground objects and air carriers of means of detecting and searching for distant objects.

The technical result is a mobile radio navigation multi-position differential-rangefinder system, which can be duplicated in case of loss of signals from global navigation systems in limited areas of the earth's surface.

The title of the invention contains the purpose, radio navigation, and its function, a multi-position differential-rangefinder system. The technical result is based on supplementing the known system with a device for forming a navigation field with time division of channels; the device for determining the difference between the ranges and its coordinates by the user of the navigation field by the analytical solution of the system of linear equations obtained by the proposed sequence of linearization of the system of hyperbolic equations, and, in addition, during the linearization, the total number of navigation posts was determined.

The technical field to which the invention relates

The invention relates to radio navigation systems for determining location or obtaining information related to location for navigation purposes by means of propagation properties of radio waves and properties of surfaces (lines) of position.

Ground-based radio navigation system - a set of interacting radio electronic and technical means located at justified points on the earth's surface and on mobile objects providing these objects with navigation information.

State of the art

Long-range navigation radio systems (rangefinder, quasi-rangefinder, differential-rangefinder) are multi-position systems based on a network of reference stations located at points with known coordinates. The essence of the procedure implemented with the rangefinder method is as follows. The reference stations at the same time emit navigation signals, according to which the consumer, having only the receiving equipment and the signal processing device, finds its location. At the same time, it uses its own standard of time, with the help of which the time of arrival from the reference station of the navigation signal is measured. The moments of time of emission and reception are synchronized with the UTC scale. Thus, the ranging method for determining the location of the consumer is based on the fact that there are highly stable time standards at each reference station and at the consumer. The quasi-measuring method of position determination is used in case of discrepancy between the time scales of the reference stations and the information consumer.

Global navigation satellite systems (GLONASS), which implement the quasi-distance measuring method, have a number of indisputable advantages: full coverage of the earth's surface and near-earth space, unification of equipment for all users, etc. [one].

However, in the course of operation and experimental research, significant shortcomings were revealed. Some of them are: insufficient noise immunity, failures and accidents on satellites, which during periods of "conflict situations" can lead to the loss of navigation support by purposeful actions.

In the known difference-ranging navigation systems (determining the coordinates of the location of the information consumer), phase methods are implemented, using which the required measurement rate can be obtained. In this case, the system also contains a reference station and several slaves. The reference and slave stations have reference oscillators that synchronize the transmitters. In the equipment of the information consumer, the received signals, after amplification, are fed to the switch, which operates synchronously with the switching of the reference and slave stations. In the structure of the consumer there is a reference generator, which, together with the phase meters, measures the phase difference of the signals from the reference station and from the slave station. Based on the phase difference of signals from the reference and slave stations, the difference between the distances between them and the information consumers is found, and the line (surface) of the position is also constructed.

Similarly, according to the phase difference of signals from the reference station and from another slave station, the difference in distances between them and the information consumer is found, and another line (surface) of position is constructed.

To determine its coordinates, the information consumer, in addition to the lines (surfaces) of the position, has the coordinates of the reference and slave stations in the database [2, 3].

Unambiguous range measurement in phase navigation systems is provided only within the carrier wavelength. To resolve the ambiguity of measurements, pulse-phase systems are used; their navigation signal is a bundle of coherent pulses, the carrier frequency of which is used for accurate, and the envelope for rough measurement of the range difference in order to eliminate the ambiguity of accurate measurements.

By the essence of the technical solution, the closest to the proposed system is the "Navigation System" with a utility model patent RU 44190 U1, application 2004130926/22, 28.04.2004 [4]. In the specified utility model, the technical result, the development of a mobile local navigation system, with the following features:

elimination of errors in determining the coordinates of the information consumer due to the instability of the frequency standards of reference stations and the information consumer;

the ability to change the rate of formation of the navigation field;

reduction of geometric factor errors.

However, the prototype does not include:

sufficiency of data on the moments of arrival of signals from the reference and slave stations for solving the system of equations to determine the coordinates of the consumer;

proof of the necessity and sufficiency of four navigation posts for solving a system of hyperbolic equations with an unambiguous determination of coordinates with the required accuracy;

analysis of the influence of the spatial position of the consumer of information for entering into the structure of the "Navigation system".

The essence of the invention

The essence of the invention consists in a set of essential features that are in a causal relationship with the improvement of the radionavigation differential-rangefinder system.

To achieve the specified technical result, the following essential features are presented:

determination of the total number of navigation posts and the formation of a system of linear equations for calculating the coordinates of the information consumer;

formation of the navigation field by the system with time division of channels;

coordinate-time support for determining the difference in the ranges of the information consumer.

In this case, the determination of the total number of navigation posts and the formation of a system of linear equations for calculating the coordinates of the information consumer is based on the transformation of the system of hyperbolic equations.

The basis for the construction of radio navigation systems on a multiposition differential-rangefinder basis is a system of hyperbolic equations of the form:

[(x ₀ -x ₁ ) ² + (y ₀ -y ₁ ) ² + (z ₀ -z ₁ ) ² ] ^0.5 - [(x ₀ -x _i ) ² + (y ₀ -y _i ) 2+ ( z ₀ -z _i ) ² ] ^0.5 = D ₁ -D _i ,

where x _i , y _i , z _i - coordinates of navigation posts (transmitters);

x ₀ , y ₀ , z ₀ - determined coordinates of the object on board;

D ₁ -D _i is the difference between the distances from the navigation object to the leading (1st) and i-th navigation post.

The entry on the right-hand side confirms that the first was accepted as the leading navigation post. When forming the structure of a multi-position differential-ranging system, it should be borne in mind that D ₁ is a segment between the post transmitter and the navigation object.

We will show the sequence of constructing a system of three linear equations and the possibility of their formation for a different number of posts. Each pair with right sides of equations (A ₁₂ -A _13), (A ₁₄ -A ₁₅₎ and (A ₁₆ -A ₁₇₎ allow relative to D ₁ and is converted to a linear form with respect to x ^_0,, y _0, z _0, A _1i = D ₁ -D _1i .

Then for the first pair, where A _{12 is} on the right, we get:

Similar transformations of the 2nd equation with A ₁₃ will give:

Равенства приводят к выражению:

Equalities lead to the expression:

With compact recording, you get:

Then the system of linear equations will take the form:

λ ₁ x ₀ + q ₁ y ₀ + ε ₁ z ₀ = -ξ ₁ ;

λ ₂ x ₀ + q ₂ y ₀ + ε ₂ z ₀ = -ξ ₂ ;

λ ₃ x ₀ + q ₃ y ₀ + ε ₃ z ₀ = -ξ ₃ .

Information consumer coordinates

Where

Δ is the determinant of the matrix

Δ _i (i = x, y, z) is the determinant of the matrix in which the corresponding column is replaced by a column of free terms.

Reducing the number of posts to five can be achieved by using the following pairs of differences:

(A ₁₂ , A ₁₃ ), (A ₁₂ , A ₁₄ ) and (A ₁₂ , A ₁₅ ).

For each of the differences within the pair, there are dependencies for D _1; the latter equate and write down a linear equation for x ₀ , y ₀ , z ₀ .

Simplification of writing the system of equations is achieved by introducing the following variables:

The system of equations will take the form:

k ₁ x ₀ + p ₁ y ₀ + s ₁ z ₀ = -ψ ₁ ;

k ₂ x ₀ + p ₂ y ₀ + s ₂ z ₀ = -ψ ₂ ;

k ₃ x ₀ + p ₃ y ₀ + s ₃ z ₀ = -ψ ₃ ,

and has a solution

FIG. 1 shows a compact record of a system of linear equations for determining the coordinates of the information consumer using five and seven navigation posts.

It is preferable to represent the radionavigation system as a time division multiplexing system. At the beginning of each of the channels, a trigger pulse is generated for the transmitter of the first (reference) navigation post. The same signal, which has passed the base d _1i (i = 2, ..., 5), is used to launch the transmitter of the i-th navigation post.

The use of the facts of signal emission by the 1st i-th navigation posts, their reception and processing in the same channel eliminates the need to set time standards and ensures the consistency of obtaining the time difference (t _i -t _1i ) and the formation of A _1i = (D ₁ - D _i ) to solve the system of equations. The number of channels is one less than the number of navigation posts. The duration of the channel is taken to be not less than the time of propagation of electromagnetic energy to the maximum navigation range.

The sum of the channels is the lifetime of the navigation field. The frequency of the formation time of the navigation field is characterized by the value of T _ns . Specific values of the number of posts, channel duration, period T _ns are introduced before using the system for its intended purpose. FIG. 2 shows diagrams illustrating the coordinate-time support of the formation of the navigation field.

It is advisable to determine the range difference on the following assumptions: the receiver of the information consumer in each channel first receives the signal from the 1st navigation post in comparison with the i-th NP, since the sum (D _i + Δd _1i ) of the two sides of the triangle is greater than the third D ₁ ; the signal from the i-th NP arrives through the time t _measi = [(D _i + d _1i ) -D ₁ ] / s, which is determined by the time interval meter. The value of t _{1i is} defined as the ratio of the calculated base d _1i along the coordinates of the 1st and i-th transmitters to the speed of light. For the system of equations calculate the difference A _1i = (D ₁ -D _i ), when D ₁ > D _i assign the sign "+", when D ₁ <D _i - "-". FIG. 3 shows a timing diagram that makes it possible to determine A _1i by a single dependence for both cases:

t _pi = t _1i -t _measi ,

A _1i = (d _1i -c⋅t _measi ).

List of drawings and other materials

FIG. 1 The system of linear equations for determining the coordinates of the information consumers of the navigation field.

FIG. 2 Coordinate-time support of the navigation field formation device.

FIG. 3 Coordinate-time support for determining the difference in ranges by the information consumer.

FIG. 4 Block diagrams of the equipment of the reference (a) and slave (b) posts for the formation of the navigation field.

FIG. 5 Functional diagram of the navigation field information consumer.

FIG. 6 Block diagram of the prototype.

Information confirming the possibility of carrying out the invention

To form the navigation field, the required number of navigation posts (five or seven) are deployed, the coordinates of which are determined by the method of topographic geodetic referencing, one of them is designated as the first (reference) one. The rest of the navigation posts (their transmitters) are removed from the coordinates of the first transmitter by the value of the base, the moment of emission of electromagnetic energy by each transmitter is synchronized with the launch pulse of the 1st navigation post, taking into account the passage of the corresponding base.

The radio navigation MNRD system represents a set of equipment of the reference and slave posts for the formation of the navigation field and the consumer of the information of the navigation field. Block diagrams of the equipment of the reference and slave posts for the formation of the navigation field are shown in Fig. 4. The scheme of the equipment of the reference post contains a device for inputting the number of posts, the duration of the channel, the period of the navigation field 1, the output of which is connected to the input of the channel formation circuit and the period of the navigation field 2, its output is connected to the inputs of the input device for entering the code and coordinates of the reference post 3, modulator 4 , an electronic switch of outputs 11, the second input of the modulator 4 is connected to the output of the device 3; modulator 4, transmitter 5, antenna 6 are connected in series; (n-1) outputs of the electronic switch are connected to the inputs of the corresponding coding devices, the outputs of which are loaded on the input of the transmitter 9, the output of the latter is connected to the antenna 8; The scheme of the equipment of the slave navigation posts contains a series-connected antenna 6, a decoupling device 12, a radio frequency amplifier 14, a decoder 15, a device for entering a position code of a post 3, a modulator 16, a transmitter 13, the output of which is connected to the second input of the decoupling device 12.

The functional diagram of the information consumer of the navigation field is shown in Fig. 5 and includes a serially connected antenna 7, a receiver 17, an electronic output switch 18, a time interval meter 19, a range difference calculator 20, a consumer coordinate determination processor 23; the second output of the receiver 17 gives rise to the serial connection of the decoder 15, the analog-to-digital converter 21, the random access memory of the coordinates of the navigation posts 22, the output of which is connected to the second input of the processor 23.

The equipment of the reference and slave posts (Fig. 4) for the formation of the navigation field operates in the following order. The field of deployment of navigation posts and determination of their location, the corresponding values of codes and coordinates for each of the posts: the reference and all slaves are entered into the code and coordinate input devices 3. Immediately before application to the input device of the number of posts 3, the channel duration, the period of the navigation field 1, data is recorded characterizing the parameters of the navigation field.

According to the data entered into the device 1, the channel formation circuit and the navigation field period 2, generates a sequence of synchronizing pulses according to the number of navigation posts. The clock sequence is shown in FIG. 2 - diagrams of voltages at the output of the formation circuit. In this case, t _k is the duration of the time channel, t _ns , T _ns are the duration and period of the formation of the navigation field, respectively.

Each synchronizing pulse of the time channel starts the modulator 4 and the input device for the code and coordinates of the reference station 3, the code and coordinates modulate the high-frequency oscillations of the transmitter 5 of the first station and radiate into space.

The same synchronizing pulse of the time channel acts on the electronic output switch 11, the outputs of which are connected to the inputs of the slave station number coding devices 10.

At the output of each encoder 10, the number of the corresponding slave post is received, the transmitter 9 and the antenna 8 transmit this number to start the transmitter corresponding to the number of the slave post after passing the base d _1i . An illustration of the formation of the launch times of the transmitters of navigation posts is shown in Fig. 2. Digit 1 shows the moments of starting the transmitter of the reference station, the time intervals t _1i separate the moments of starting the transmitter of the i-th slave station and depend on the selected base d _1i .

The equipment of the slave navigation posts (Fig. 4, b) coincides in structure and functions with that in the prototype. According to technical features, the equipment is a repeater, at the command of a signal from the composition of synchronizing pulses, the antenna emits a code number and rectangular coordinates of the anchor point of each post.

Thus, in each time channel t _{k of the} duration of the formation of the navigation field t _ns, electromagnetic energy is emitted in the following sequence: the code number of the 1st (reference) post, its coordinates, after time t _{1i the} code number of the i-th (slave) post, its coordinates ; in this case, electromagnetic oscillations from the first post will reach the information consumer first, from the i-th post - the second.

The antenna of the user of the information of the navigation field (Fig. 6) receives signals, the receiver amplifies and converts them. The left branch of the functional diagram - the decoder identifies the coordinates to the corresponding posts, the analog-to-digital converter performs its function of converting the analog into a digital, the digitized coordinates of all posts are entered into RAM. The second output of the receiver and the electronic switch of the output provide signals from the reference post to the 1st input and from the slave i-th post to the 2nd input of the time interval meter t _MEZ . The range difference calculator determines the range difference D ₁ -D _i = A _1i = c⋅ (t _1i -t _measu ), this procedure is described in detail in Fig. 3, coordinate-time provision of the distance difference by the information consumer.

The coordinate determination processor implements the algorithm for solving the system of linear equations shown in FIG. 1 and when describing the essential feature.

Literature

1. GLONASS: principles of construction and functioning / Ed. A.I. Perova, V.N. Kharisova. - 3rd ed., Rev. - M .: Radiotekhnika, 2005 .-- 688 p.

2. Yu.I. Nikitenko, V.I. Bykov, Yu.M. Ustinov Ship radio navigation systems. -M .: Transport, 1992 .-- 336 p.

3. GOST R 54025-2010. Radio navigation system "Chaika".

4. "Navigation system", patent for a useful model RU 44190 U1, application 2004130926/22, 28.10.2004.

Claims (1)

A radio-navigation multi-position differential-rangefinder system based on the information-energy interaction of the reference and slave navigation posts and the information consumer and containing in the equipment of the reference navigation post a device for entering the code and coordinates of the post, a modulator, a transmitter and an antenna, in the equipment of the slave posts, an antenna, a decoupling device, radio frequency amplifier, decoder, input device for code and station coordinates, modulator and transmitter; in the equipment of the information consumer, an antenna, a receiver, a decoder, RAM codes and coordinates of navigation posts, characterized in that it contains: in the equipment of the reference post, a device for entering the number of posts, channel duration, navigation field period, the output of which is connected to the input of the channel formation circuit and the period navigation field, the output of the latter is connected to the inputs of the input device for the code and coordinates of the reference post, the modulator and the electronic switch of outputs, each of which is connected to the input of the corresponding encoder, the outputs of the latter are connected to the input of the transmitter, its output is loaded onto the antenna; in the information consumer's equipment, the output of the receiver is connected to the input of the electronic output switch, both outputs of the switch are connected to the inputs of the time interval meter, the output of which is loaded to the input of the range difference calculator, the output is connected to the input of the processor for determining the coordinates of the consumer, a decoder, an analog-to-digital converter, connected in series, The coordinate RAM is loaded on the second input of the processor.

Images