RU2558647C1 - Navigation system using earth's natural and artificial fields - Google Patents

Abstract

FIELD: physics, navigation.

SUBSTANCE: invention relates to aviation instrument-making. The disclosed navigation system is designed to provide high-precision navigation based on integrated information processing of artificial Earth field navigation systems and multiple physical Earth fields. The navigation system is built on an integrated modular architecture, wherein the inertial system, barometric altimeter, field sensors, on-board digital computer and artificial Earth field navigation system, which are components of the system, are in the form of separate modules with corresponding sensitive elements and are installed in a single housing.

EFFECT: present navigation system enables, via integrated information processing of artificial Earth field navigation systems and multiple physical Earth fields, to improve accuracy of the navigation system, as well as reliability thereof when operating in jamming conditions or breakdown of a satellite constellation; by switching from a federative structure of the system to an integrated modular architecture, the invention eliminates asynchrony and delay of data streams from the inertial system, the field sensors and the barometric altimeter in the on-board digital computer, thereby improving accuracy thereof, reducing the weight, size and cost and simplifying the cable system on-board aircraft.

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Description

The invention relates to the field of aviation instrumentation, in particular to navigation systems for aircraft (LA).

In the closest analogue [Krasovsky A.A., Beloglazov I.N., Chigin G.P. Theory of correlation-extreme navigation systems. - M.: Science, Main Edition of Physics and Mathematics, 1979, p. 323] presents a block diagram of a navigation system that uses the Earth’s natural fields to correct inertial coordinates, consisting of an inertial system (IS), a field sensor ( DP), bar altimeter and on-board digital computer (BTsVM). Various sensors of the Earth’s natural physical fields (FPZ) can act as a DP, for example, radio altimeters for measuring the terrain of the Earth’s surface (RPS), magnetometers for measuring anomalies of the Earth’s magnetic field (MPZ). The digital computer stores reference cards of the corresponding FPZ. The principle of operation of this navigation system is that the input information in the form of FPZ (D) signals generated by the DP arrives at the digital computer, where the correction output signal is determined by comparing the current DP signal with the reference card. Produced in BTsVM extreme correction signal used for clarification of the IP signal (x, y, H, _uc, θ, γ, ψ). The signal from the bar altimeter (H) is used to correct the vertical channel of the ANN.

The disadvantage of the closest analogue are:

- restrictions on high-precision navigation in flight areas over terrain with low information content FPZ;

- asynchrony and delay of data streams from the IS, DP and bar altimeter in the digital computer, due to the federal structure of the construction of the navigation complex, which leads to a decrease in its accuracy characteristics;

- large weight and size and cost characteristics of the navigation complex and the presence of a complex cable system on board the aircraft (LA) for the organization of data transfer, which is also due to the federal structure of the complex.

The objective of the invention is to provide high-precision navigation regardless of the information content of the FPZ, as well as reducing the overall dimensions of the navigation system.

This result is achieved by the fact that in the navigation complex containing the digital computer, with the input of which the outputs of the IC, bar altimeter and DP are connected, an additional sensor for another FPZ and a navigation system for artificial Earth fields (SNIPZ) connected to the input to the digital computer that implements the correction of the IP data by means of integrated processing of information from SNIPZ and several FPZs, and the federal structure of the navigation complex is changing to an integrated module architecture (IMA), for which IP, a bar altimeter, both DP, BTsVM and SNIPZ are performed in the form separate modules with corresponding sensitive elements and are installed in a single housing.

Figure 1 shows a block diagram of a navigation complex using natural and artificial Earth fields (NK-EIPZ), comprising: 1 - the NK-EIPZ building, 2 - IP module, 3 - DP1 module, 4 - DP2 module, 5 - module SNIPZ, 6 - bar altimeter module, 7 - BTsVM module, 8 - sensitive elements of IS, DP and SNIPZ.

To reduce the weight and size and cost characteristics when designing the NK-EIPZ modules and case, it is advisable to use international standards for small-sized systems, for example, the PC104 + form factor described in [PC / 104-Plus Specification Version 2.0 November 2003].

Information exchange of data between the modules is carried out on the internal bus, which ensures the elimination of delays in the transmission of data and their synchronism. As the internal bus, you can choose, for example, the PCI 32-bit PC / 104-Plus bus described in [PCI Local Bus Specification Production Version Revision 2.1 June 1, 1995].

The NK-EIPZ 1 building provides a constructive opportunity to implement the IMA principles by installing the modules included in the NK-EIPZ. The basis of the body is a spatial frame (chassis) with side walls. Structurally, the chassis can be made as a subunit (rack) of the modified parts of the Euromechanics standard. The front and rear walls, the bottom and the cover, the package of modules of the PC104 + format are attached to it, thereby creating the unity of the design as a whole and ensuring the strength and resistance of the product to external factors.

The IS 2 module provides processing of incoming information from a sensitive element (inertial sensors) about the geographical coordinates, speeds and angular evolutions of the aircraft. The module IP 2 can be built in accordance with well-known principles set forth, for example, in [Pomykaev II, Seleznev VP, Dmitrochenko L.A. Navigation devices and systems. - M .: Engineering, 1983, pp. 226-329].

DPZ and DP4 modules provide measurement of FPZ signals. The most common FPZ in extreme correction systems are the RPZ and MPZ.

To measure the RPS, the DPS module is a transceiver module of a radio altimeter (PPR). The PPR module is connected via high-frequency connectors to its sensitive elements (transmitting and receiving antennas). The PPR module can be built in accordance with the well-known principles set forth, for example, in [Finkelstein MI. Basics of radar. - M .: Radio and communications, 1983, p. 15-20, 108-115].

For measuring the magnetic overdrive, the DP4 module is a magnetometer signal converter module (PSM). The PSM module is connected via a connector to a sensitive element (magnetometric sensor). The MPZ module can be built in accordance with well-known principles set forth, for example, in [Beloglazov I.N., Dzhandzhgava G.I., Chigin G.P. Fundamentals of navigation through geophysical fields. - M .: Nauka, 1985, pp. 88-99].

Thanks to the IMA principles, more than two DP modules can be installed in the NK-EIPZ, which expands the field of application of extreme correction and improves its accuracy characteristics.

The SNIPZ 5 module provides measurement of navigation parameters based on the processing of data on artificial fields of the Earth. Such systems include the global satellite navigation system (SNA), the radio navigation system of near navigation, etc. In particular, the SNA provides the determination of the current coordinates, time and velocity vector from the signals of the GLONASS, GPS and SBAS satellite radio navigation systems. The SNA module can be built on the basis of a satellite navigation system receiver, for example, MNP-7 [NAVIGATION RECEIVER MNP-M7. INSTRUCTIONS FOR USE OF CVI.468157.113 OM].

The barometer altimeter module 6 provides the measurement of static, dynamic atmospheric pressure and the processing of these signals to provide information on the absolute flight altitude. The bar altimeter module can be built in accordance with well-known principles set forth, for example, in [Pomykaev II, Seleznev VP, Dmitrochenko L.A. Navigation devices and systems. - M.: Engineering, 1983, pp. 48-50].

The BTsVM 7 module provides complex processing of incoming information from the IS2, DPZ, DP4, SNIPZ 5, bar altimeter 6 modules with the aim of determining navigation parameters. At the same time, several methods are used to correct IP errors that have a diverging nature in time:

- extreme correction for the RZP and MPZ;

- correction according to IPZ.

Extreme correction based on the processing of reference information about the REE and the current data of the radio altimeter and the baroinertial filter provides autonomous determination of coordinates over a medium-intersected and highly intersected relief with an accuracy of 50-100 m (σ).

Extreme correction based on the processing of reference information about the magnetic recalculation, recalculated to the absolute flight altitude, and current magnetometer data provides an autonomous determination of coordinates over all types of surfaces, including water, but with the worst accuracy of 200-500 m (σ).

An extreme correction for the FPZ (RZP and MPZ) based on the analysis of the behavior of the functionals allows, in addition to issuing corrections to the coordinates (Δφ - in latitude, Δλ - in longitude) to evaluate their reliability and error (σ).

Correction by IPZ, in particular satellite correction, provides high-precision determination of coordinates from units of meters (in differential mode) to 30 m and does not depend on the information content of the FPZ. However, this type of correction is not autonomous, and therefore vulnerable to radio interference or the satellite constellation.

The novelty of the proposed approach lies in the fact that the module 7 BCM simultaneously produces all types of correction. In the presence of significant amendments developed during extreme correction ICR (Δφ _psh, Δλ _psh) and MPD (Δφ _mPas, Δλ _mPas), the accuracy of the estimated satellite correction (Δφ _SNA, Δλ _SNA) on the basis of the following criteria:

if

or, if | Δφ _inventories -Δφ _SNA | ≤δφ and | Δλ _inventories -Δλ _SNA | ≤δλ,

then the amendments issued by the SNA are reliable.

In expression (1), δφ and δλ are the permissible values in the discrepancy between the data of extreme correction according to the FPZ and satellite correction.

If extreme correction is carried out according to the 2nd FPZ (RZP and MPZ) and correction according to the SNA, and all three issued corrections to the IP coordinates are reliable, then the final linear unbiased estimate of the corrections ΔZ (Δφ or Δλ) is calculated based on their weighted amounts in accordance with the following expression deduced by the authors:

where D ₁ - the variance of the errors of extreme correction for REE;

D ₂ - the variance of the errors of extreme correction according to the MPZ;

D ₃ - dispersion of satellite correction errors;

x ₁ - correction for Δφ or Δλ of extreme correction for REE;

x ₂ - correction for Δφ or Δλ of extreme correction according to the MPZ;

x ₃ - correction for Δφ or Δλ satellite correction.

When correcting for two reliable amendments, expression (2) is simplified:

Thus, in the digital computer, the correction of IP data is implemented through the integrated processing of IPZ information and several FPZs. The above algorithm allows you to increase the accuracy characteristics of the navigation system, as well as the reliability of its operation in the setting of radio interference or incapacitation of a satellite constellation.

A computer can be built on the basis of a high-performance PC-104 + form factor processor board, for example, Advantech PCM-3362 with an integrated Atom N450 central processor with a clock frequency of 1.6 GHz, up to 2 GB RAM, 2 GB read-only memory [CPU board PC / 104-Plus format with Atom N450 processor. Specification].

Sensitive elements 8 provide modules IS2, DP3, DP4, SNIPZ 5 primary information.

As an IS sensitive element, for example, inertial sensors based on micromechanical elements can be used [A. Vlasenko Integrated gyroscopes iMEMS - angular velocity sensors of Analog Devices Russian Representative Office Analog Devices, Inc. Electronic components No. 2 of 2003].

As a sensitive element of the RP RZP (radio altimeter), you can use antennas built on the well-known principles set forth, for example, in [Reference radar. Editor M. Skolnik. - M .: Soviet Radio, 1978, pp. 96-101].

As a sensitive element of the DP MPZ (magnetometer), you can use a magnetometric flux-gate sensor, built on the well-known principles set forth, for example, in [Beloglazov I.N., Dzhandzhgava G.I.,. Chigin G.P. Fundamentals of navigation through geophysical fields. - M .: Nauka, 1985, pp. 88-99].

As a sensitive element SNIPZ, such as SNA, you can use, for example, navigation antennas [Catalog "Navigation equipment GLONASS / GPS" OJSC "Izhevsk radio factory"].

Claims (1)

A navigation complex containing an on-board digital computer (BCM), with the input of which the outputs of an inertial system (IS), a bar altimeter and a sensor of the Earth’s natural physical field (FPZ) are connected, characterized in that an additional sensor of another FPZ and a navigation system for artificial Earth fields (SNIPZ) connected to the input of the digital computer that implements the correction of IS data by means of integrated processing of information from the SNIPZ and several physical fields of the Earth, structurally constructed using an integrated-modular archite round (IMA), which IP barovysotomer both LRF sensor, and digital computer SNIPZ performed as separate modules with the respective sensing elements and mounted in a single housing.