RU2633703C1 - Integrated inertial-satellite systems of orientation and navigation - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: system is proposed comprising an antenna module of the receiving equipment of a satellite navigation system, comprising, for example, two receiving antennas spaced at a distance less than the wavelength of the carrier frequency, is fixed rigidly in the axes of the measuring unit of the inertial module in the plane of the object deck; the measuring unit of the inertial module together with the antenna module of the receiving equipment of the satellite navigation system is mounted on a rotating base equipped with a drive to provide modulation rotation relative to the body of the non-carded inertial measurement module about an axis orthogonal to the deck; the drive is provided with an angle sensor measuring the rotation anglevalues of the measuring unit with the antenna module with respect to the body of the non-carded inertial measurement module tied to the axes of the object.

EFFECT: increasing the accuracy of generating object orientation parameters while reducing the length of the antenna base to the level of the carrier frequency wavelength of the satellite signal, expanding the possibilities for calibrating zero accelerometer and gyroscope offsets on the mobile object.

6 cl, 6 dwg

Description

FIELD OF TECHNOLOGY

The invention relates to the field of navigational instrumentation of aircraft and marine vessels.

BACKGROUND OF THE INVENTION

One of the main problems on the way to creating a miniature integrated orientation and navigation system designed primarily for small-sized aviation and marine objects based on a gimballess inertial measuring module containing a low-precision measuring unit, for example, on fiber-optic gyroscopes or micromechanical sensors, and satellite receiving equipment navigation systems, is the problem of providing requirements for the accuracy of the development of the course.

Hereinafter, small-sized objects are understood as inhabited and unmanned (remotely controlled or according to a predetermined algorithm of actions) river and sea vessels with a gross tonnage of up to 500 tons, as well as unmanned aerial vehicles.

Recently, they have been trying to solve the problem of meeting heading requirements in an integrated orientation and navigation system with a low-precision inertial inertial measuring module of low accuracy, in particular, by creating satellite navigation systems for mobile objects with phase measurements from receiving antennas spaced apart at a certain distance ( antenna base).

This new direction in marine and aviation instrumentation is associated with the development of the so-called GPS-compasses (satellite compasses), using an inertial measuring module.

Methods for determining the orientation parameters of an object, based on the use of phase measurements from diversity antennas in the receiving equipment of navigation navigation systems, are given in the description of the family of domestic multi-antenna receiving equipment of RTO satellite navigation systems [1], as well as in [2, 3, 4, 5].

In well-known schemes for constructing an integrated orientation and navigation system, for example, described in [6, 7, 8, 9], both with and without a gimballess inertial measuring module, multi-antenna receiving equipment of a satellite navigation system with phase measurements, providing, with a certain discreteness, an autonomous generation of object orientation parameters.

The task of determining the orientation of an object using phase measurements, as is known, requires a solution to the problem of the ambiguity of phase measurements, because the antenna base in these systems ranges from 0.7 m to 1.5 m, which is significantly greater than the wavelength of the carrier signal of the SNA component of the order of 0.19 m. In existing schemes for constructing orientation systems using phase measurements, the use of sufficiently long (1 m and more) antenna bases due to the need to achieve a given level of accuracy in generating orientation parameters. So, for most known systems, a level of accuracy of the order of 0.5 ° is characteristic with an antenna base length of 1 m.

), достаточно сложного программного обеспечения и существенной задержки времени при выработке первого определения курса объекта. There are various ways to solve this problem [10]. All of them require the simultaneous observation and processing of phase measurements from a constellation of navigation satellites (

), rather complicated software and a significant delay in the development of the first definition of the course of the object.

The joint processing of data from a gimballess inertial measuring module and receiving equipment of a satellite navigation system in the considered schemes for constructing an integrated orientation and navigation system is usually performed at the level of orientation parameters.

The patent [11] describes an integrated orientation and navigation system for marine objects.

The device described in [11] is selected as the closest analogue (prototype) of the claimed device.

The integrated orientation and navigation system, adopted as a prototype, contains miniature receiving equipment of a satellite navigation system, including an antenna module with two or more antennas, and the reference antenna is located at the maximum possible distance from the center of mass of the object, limited by the size of the object; gimballess inertial measuring module; measuring unit with gyroscopes, accelerometers and providing electronics; calculator of a gimballess inertial measuring module; unit for calculating the orientation parameters of the object; unit for calculating the navigation parameters of the object; complex information processing unit; block for the formation and resolution of the ambiguity of difference phase measurements.

.A distinctive feature of the prototype is the formation and processing in the Kalman filter of an integrated orientation and navigation system for differential phase measurements, as well as the original method used to eliminate the ambiguity of these measurements. These measurements are the difference between the calculated (generated using data from the gimballess inertial measuring module) and measured (generated from the receiving equipment of the satellite navigation system) second differences of phase measurements from one or more pairs

.

и

) поступают в вычислитель бескарданного инерциального измерительного модуля. В блоке вычисления параметров ориентации решается задача ориентации и вычисляются параметры ориентации измерительного блока, которые и являются параметрами ориентации объекта с точностью до погрешностей привязки осей измерительного блока

к осям объекта

. В блоке вычисления навигационных параметров решается навигационная задача, т.е. вычисление составляющих вектора линейной скорости и координат местоположения объекта – навигационных параметров.In the prototype, the output of the measuring unit of the gimballess inertial measuring module (

and

) enter the calculator of the gimballess inertial measuring module. In the unit for calculating orientation parameters, the orientation problem is solved and the orientation parameters of the measuring unit are calculated, which are the orientation parameters of the object up to errors in the binding of the axes of the measuring unit

to the axes of the object

. In the block for calculating the navigation parameters, the navigation problem is solved, i.e. calculation of the components of the linear velocity vector and the coordinates of the location of the object - navigation parameters.

,

,

,

,

. Эти данные также поступают в вычислитель бескарданного инерциального измерительного модуля соответственно в блоки разрешения неоднозначности разностных фазовых измерений и комплексной обработки информации, где осуществляется совместная обработка информации бескарданного инерциального измерительного модуля и приёмной аппаратуры спутниковой навигационной системы, т.е. формирование и разрешение неоднозначности разностных фазовых измерений для их вторых разностей, а также формирование разностных измерений по первичным навигационным параметрам. Затем в блоке комплексной обработки информации осуществляется обработка разностных измерений с использованием алгоритма фильтра Калмана. По оценкам, полученным на выходе фильтра Калмана, в обратной связи осуществляется коррекция погрешностей бескарданного инерциального измерительного модуля как по параметрам ориентации, так и по навигационным параметрам и дрейфам гироскопов, а также коррекция погрешностей разностных фазовых измерений, формируемых в блоке разрешения неоднозначности разностных фазовых измерений.The output data of the receiving equipment of the satellite navigation system are:

,

,

,

,

. These data also go to the calculator of the gimballess inertial measuring module, respectively, to the ambiguity resolution blocks of difference phase measurements and complex information processing, where the information is processed jointly from the gimballess inertial measuring module and the receiving equipment of the satellite navigation system, i.e. the formation and resolution of the ambiguity of difference phase measurements for their second differences, as well as the formation of difference measurements by primary navigation parameters. Then, in the complex information processing block, the processing of difference measurements is carried out using the Kalman filter algorithm. According to the estimates obtained at the output of the Kalman filter, feedback is corrected for errors in the gimballess inertial measuring module both in orientation parameters and in navigation parameters and gyro drifts, as well as error correction of difference phase measurements generated in the ambiguity resolution block of difference phase measurements.

объекта.In this case, the antenna module of the receiving equipment of the satellite navigation system is not structurally connected in any way with the measuring unit of the gimballess inertial measuring module, it is located in the axes

object.

, ортогональной плоскости палубы, приводящих к росту погрешностей интегрированной системы ориентации и навигации в выработке параметров ориентации, что особенно актуально при построении интегрированной системы ориентации и навигации на измерительном блоке низкой точности.The disadvantages of the prototype include the need to use an antenna base with a length of at least 1 m in order to ensure the accuracy of the development of a course angle of about 0.5 ° (P = 0.997) and the use of signals from only one global satellite navigation system (GNSS): GPS with code division of signals. To clarify all orientation parameters, it is necessary to use at least one antenna base (1 m or more in length) with two antennas and two (or one specialized, which allows several antennas to be connected at the same time) receivers of the satellite navigation system. This inevitably leads to significant weight and size characteristics and an increase in the cost of the system. In addition, with such a scheme for constructing an integrated orientation and navigation system, it is difficult to evaluate all the instrumental errors of the measuring unit of the gimballess inertial measuring module, in particular, accelerometer drifts and errors of the gyroscope scale factor installed along the axis

, orthogonal to the plane of the deck, leading to an increase in errors in the integrated orientation and navigation system in the development of orientation parameters, which is especially important when building an integrated orientation and navigation system on a low-precision measuring unit.

SUMMARY OF THE INVENTION

The objective of the invention is to improve the accuracy and minimize the weight and size characteristics of an integrated orientation and navigation system containing a miniature gimballess inertial measuring module and receiving equipment of satellite navigation systems with phase measurements and spaced antennas.

The problem is solved in the proposed integrated inertial-satellite orientation and navigation system containing a gimbal-free inertial measuring module, including a measuring unit with at least three gyroscopes and at least three accelerometers and a calculator, including a parameter generation unit orientation, a unit for generating navigation parameters, an integrated information processing unit, a unit for generating and resolving the ambiguity of difference phase measurements, and also containing receiving equipment of satellite navigation systems (both with code and frequency separation of navigation satellite signals), including an antenna module containing at least two antennas spaced on the corresponding antenna base,

the unit for generating and resolving the ambiguity of difference phase measurements is made with the possibility of generating differential phase measurements of the second phase differences and resolving their ambiguity, processing the information received from the unit for generating orientation parameters, the unit for generating navigation parameters, the unit for complex processing of information, and the receiving equipment for satellite navigation systems ,

wherein the complex information processing unit is configured to generate differential measurements by navigation parameters, process information received from the navigation parameters generating unit, the unit for generating and resolving the ambiguity of the differential phase measurements and receiving equipment of satellite navigation systems,

while the measuring unit is configured to transmit information about the components of the angular velocity of the object to the input of the block generating orientation parameters, information about the components of linear acceleration of the object to the input of the block generating navigation parameters,

the unit for generating orientation parameters is configured to transmit information about the orientation parameters to the unit for generating navigation parameters and to the unit for generating and resolving the ambiguity of difference phase measurements,

the unit for generating navigation parameters is configured to transmit information about the coordinates of the place and the components of the linear velocity of the object in the complex information processing unit and the unit for generating and resolving the ambiguity of the difference phase measurements,

complex information processing unit is configured to transmit information

- on the estimates of the errors in the orientation parameters of the measuring unit of the gimballess inertial measuring module in the unit for generating orientation parameters,

- on the estimates of the drifts of gyroscopes in the block generating orientation parameters,

- about the estimates of the errors of the coordinates of the measuring unit of the gimballess inertial measuring module and the errors of the components of the linear velocity of the object in the block generating navigation parameters,

- on the estimates of the errors of the difference phase measurements of the second phase differences in the block for the formation and resolution of the ambiguity of the difference phase measurements

and with the possibility of receiving and processing information about the coordinates of the place and the components of the linear speed of the object from the unit for generating navigation parameters, about the measured values of the navigation parameters received from the receiving equipment of satellite navigation systems, about the measured values of the second phase differences of the signals of the navigation satellites coming from the forming unit and resolving the ambiguity of difference phase measurements,

the unit for generating and resolving the ambiguity of difference phase measurements is configured to transmit information about the difference phase measurements of the second phase differences to the complex information processing unit and with the possibility of receiving and processing information

- about the complete phase differences of the signals of the navigation satellites, the coordinates of the navigation satellites coming from the receiving equipment of satellite navigation systems,

- about the orientation parameters coming from the block generating orientation parameters,

- about the coordinates of the place and the components of the linear velocity of the object coming from the block generating navigation parameters,

- on the estimates of the errors of the difference measurements of the second phase differences of the signals of the navigation satellites coming from the complex information processing unit.

The claimed system differs from the known solution in that the gimballess inertial measuring module and antenna module are made with the possibility of rotation relative to the geographic axes in the horizontal plane, and the complex information processing unit and the unit for generating and resolving the ambiguity of the difference phase measurements are made with the possibility of using phase difference measurements of navigation signals satellites of various global navigation satellite navigation systems (both with code and frequency signal separation).

In a preferred embodiment, the gimballess inertial measuring module is equipped with a drive with an angle sensor configured to provide modulation rotation and measure the angle of rotation of the measuring unit around an axis orthogonal to the deck.

The unit for generating orientation parameters can be configured to receive information about the angle of rotation of the drive from the angle sensor.

The complex information processing unit can be made with the possibility of generating and transmitting information about the estimates of the errors of the orientation parameters received at the input of the orientation parameter generating unit, information about the error of the scale factor of the gyroscope of the measuring unit installed along the axis of rotation of the measuring unit supplied to the input of the orientation generation unit .

The complex information processing unit can be configured to generate and transmit information about estimates of errors in the coordinates of the location and components of the linear velocity of the object, which is input to the unit for calculating navigation parameters, information about estimates of drift of accelerometers, input to the unit for calculating navigation parameters.

The antenna module of the receiver equipment of satellite navigation systems can be rigidly installed in the axes of the measuring unit of the gimballess inertial measuring unit in a plane parallel to the deck of the object, so that the distance between the antennas is less than the wavelength of the carrier frequency of the satellite signal.

The claimed system has the following main differences:

- the antenna module of the receiving equipment of satellite navigation systems, containing at least two receiving antennas spaced less than the wavelength of the carrier frequency of the satellite signal, are mounted rigidly in the axes of the measuring unit of the inertial module in the plane of the deck of the object;

- the measuring unit of the inertial module, together with the antenna module of the receiving equipment of satellite navigation systems, is mounted on a rotating base equipped with a drive for modulating rotation relative to the body of the gimballess inertial measuring module around an axis orthogonal to the deck;

- the drive is equipped with an angle sensor measuring the angle of rotation of the measuring unit with the antenna module relative to the frameless inertial measuring module attached to the axes of the object;

измерительного блока бескарданного инерциального измерительного модуля.- during the rotation of the measuring unit of the gimballess inertial measuring module, a greater number (in comparison with the prototype) of the instrumentation errors of the measuring unit are calibrated: additionally, the drift of the accelerometers [12, 13] and the error of the scale factor of the gyroscope installed along the axis

measuring unit of a gimballess inertial measuring module.

The implementation of these measures with appropriate joint data processing of the receiving equipment of satellite navigation systems and a gimballess inertial measuring module in an integrated orientation and navigation system (navigation parameters, phase measurements) allows, in comparison with the prototype, to achieve the following technical result: a significant increase in the accuracy of generating object orientation parameters when reducing the length of the antenna base to the level of the wavelength of the carrier signal

, expanding the possibilities for calibrating on a moving object displacements of zeros of accelerometers and a gyroscope mounted along the axis

, a gimballess inertial measuring module, reducing the overall dimensions of the integrated orientation and navigation system by 2 or more times.

BRIEF DESCRIPTION OF THE DRAWINGS

In FIG. 1 shows a block diagram of a proposed integrated orientation and navigation system.

двумя антеннами на антенной базе 23,5 см. FIG. 2, 3, 4 illustrate the results of bench tests of a prototype of an integrated orientation and navigation system, including a measuring unit on STIM 300 micromechanical sensors from Sensonor (Norway) and two receiving equipment of the 1K-181 satellite navigation system from the Russian Institute of Radio Navigation and Time (OJSC) ( Russia) with spaced along the transverse axis

two antennas on an antenna base of 23.5 cm.

In FIG. 5 shows drift estimates of micromechanical gyroscopes.

In FIG. Figure 6 shows the estimates of the residual ambiguity of the difference phase measurements.

MODE FOR CARRYING OUT THE INVENTION

In FIG. 1 adopted the following notation:

1 - miniature receiving equipment of satellite navigation systems (PA SNA), containing one specialized or two (or more) receiving equipment of satellite navigation systems and two (or more) antennas spaced at the respective antenna bases and forming the antenna module;

2 - gimballess inertial measuring module (BIIM);

3 - measuring unit with micromechanical gyroscopes and accelerometers, and providing electronics;

4 - calculator of the gimballess inertial measuring module;

, измеряемый гироскопами;5 - unit calculating the orientation parameters (ON) of the object (BVPO), the input of which, among other signals, receives the absolute angular velocity vector

measured by gyroscopes;

, измеряемый акселерометрами;6 - unit for calculating the navigation parameters (NP) of the object (BVNP), the input of which, among other signals, receives the apparent acceleration vector

measured by accelerometers;

7 - integrated information processing unit (BKOI), the input of which, among other signals, includes:

,

– измеренные и откорректированные значения дальности и радиальной скорости для каждого из наблюдаемых

соответственно; -

,

- measured and adjusted values of range and radial velocity for each of the observed

respectively;

,

– эфемериды (значения декартовых координат и составляющих вектора линейной скорости относительно Земли в проекциях на гринвичские оси) для

; -

,

- ephemeris (values of Cartesian coordinates and components of the linear velocity vector relative to the Earth in projections on the Greenwich axis) for

;

8 - unit for the formation and resolution of the ambiguity of difference phase measurements (BFiRNRFI), the input of which (among other signals) includes:

– полные разности фаз сигналов, принимаемых приёмной аппаратурой спутниковой навигационной системы в точках размещения антенн;-

- full phase differences of the signals received by the receiving equipment of the satellite navigation system at the antenna locations;

– эфемериды (значения декартовых координат в проекциях на гринвичские оси) для

;-

- ephemeris (the values of Cartesian coordinates in projections on the Greenwich axis) for

;

измерительного блока инерциального измерительного модуля в плоскости

(находящейся в плоскости палубы объекта);9 - antenna module of the receiving equipment of satellite navigation systems, containing at least two antennas spaced on the corresponding antenna base. In this case, the AM is rigidly fixed in the axes

measuring unit inertial measuring module in the plane

(located in the plane of the deck of the object);

, ортогональной плоскости палубы, относительно корпуса бескарданного инерциального измерительного модуля.10 - drive, providing the rotation of the measuring unit together with the antenna module of the receiving equipment of satellite navigation systems around the axis

, orthogonal to the plane of the deck, relative to the hull of the gimballess inertial measuring module.

измерительного блока вместе с антенным модулем приёмной аппаратуры спутниковых навигационных систем относительно корпуса бескарданного инерциального измерительного модуля;11 - angle sensor that measures the angle of rotation

a measuring unit together with an antenna module of the receiving equipment of satellite navigation systems relative to the body of a gimballess inertial measuring module;

Hereinafter, a measuring unit based on micromechanical sensors is considered, including micromechanical gyroscopes of accuracy class 10 ° / h, which corresponds to a low-precision fiber-optic gyroscope. Testing with a measuring unit on micromechanical sensors was determined by practical expediency. All the following research results apply equally to the measuring unit on fiber-optic gyroscopes, comparable to the measuring unit on micromechanical sensors in terms of error. In the future, if this is not specifically specified, the indicated measuring unit on micromechanical sensors will be considered.

The implementation of these conditions is the main difference between the proposed device and the prototype, which requires changes in the design of the gimballess inertial measuring module 2 and the antenna module of the receiving equipment 1 of satellite navigation systems, as well as taking into account additional communication between the angle sensor 11 and the calculator 4 of the gimballess inertial measuring module .

Algorithmic support of the blocks of the calculator 4 of the gimballess inertial measuring module of the proposed scheme of the integrated orientation and navigation system (Fig. 1) is similar to the operation algorithms of the corresponding prototype blocks with the exception of

- block 8 for generating and resolving the ambiguity of differential phase measurements, where when generating differential measurements of the second phase differences, information on the wavelength of signals of navigation satellites with frequency separation of their signals is additionally taken into account;

измерительного блока 3 бескарданного инерциального измерительного модуля 2 и дополнительно вводится расширенная модель погрешностей вторых разностей фаз блока формирования и разрешения неоднозначности разностных фазовых измерений 8, - block 7 of integrated information processing, where additionally developed estimates of the drift of the accelerometers and the error of the scale factor of the gyroscope installed on the axis

measuring unit 3 of the gimballess inertial measuring module 2 and additionally introduced an expanded model of errors of the second phase differences of the unit for forming and resolving the ambiguity of the differential phase measurements 8,

поворота измерительного блока 3 с антенным модулем 9 относительно корпуса бескарданного инерциального измерительного модуля 2. При этом в блоке 5 вычисления параметров ориентации будут вычисляться как параметры ориентации измерительного блока 3 бескарданного инерциального измерительного модуля 2 (матрица направляющих косинусов

), так и параметры ориентации объекта (матрица направляющих косинусов

и углы курса

, тангажа

и крена

), поступающие на выход интегрированной системы ориентации и навигации (фиг. 1).- unit 5 for calculating the orientation parameters of the calculator of the proposed integrated orientation and navigation system, which additionally introduces the readings of the angle sensor 11 located on the rotation axis of the measuring unit 3 and measuring the angle

rotation of the measuring unit 3 with the antenna module 9 relative to the housing of the gimballess inertial measuring module 2. In this case, in block 5, the calculation of orientation parameters will be calculated as the orientation parameters of the measuring unit 3 of the gimballess inertial measuring module 2 (matrix of guide cosines

), as well as the orientation parameters of the object (the matrix of guide cosines

and course angles

pitch

and roll

) received at the output of the integrated orientation and navigation system (Fig. 1).

, (1)

, (one)

. Where

.

перехода от осей измерительного блока 3 (

) к осям географического сопровождающего трёхгранника (

), а не матрицу

перехода от осей объекта (

) к гринвичским осям

.The difference is also that in block 6 of the calculation of navigation parameters and block 8 of the formation and resolution of the ambiguity of the difference phase measurements of the calculator 4 of the inertial inertial measuring module of the proposed integrated orientation and navigation system, it is necessary to use, in contrast to the prototype, a matrix

transition from the axes of the measuring unit 3 (

) to the axes of the geographic accompanying trihedron (

), not the matrix

transition from the axes of the object (

) to the Greenwich axes

.

The proposed integrated orientation and navigation system works as follows.

As in the prototype [11], as well as in [14], the formation of the second differences of the measured values of the phase measurements is performed in block 8 for resolving the ambiguity of the difference phase measurements (Fig. 1):

. (2)

. (2)

– измеренное значение направляющего косинуса орта

(радиус-вектора, соединяющего опорную антенну и

) относительно антенной базы

для

.Where

- measured value of the directing cosine of the unit vector

(radius vector connecting the reference antenna and

) relative to the antenna base

for

.

учитывается информация о частотах излучаемых навигационными спутниками сигналов при частотном их разделении.The difference is that when defining

information on the frequencies emitted by navigation satellites of signals during frequency separation is taken into account.

расчётных (с использованием данных бескарданного инерциального измерительного модуля) значений фазовых измерений также производится в блоке 8 разрешения неоднозначности разностных фазовых измерений (фиг. 1).Second Difference Formation

calculated (using data from the gimballess inertial measuring module) phase measurements are also performed in block 8 for resolving the ambiguity of the differential phase measurements (Fig. 1).

The input data of block 8 for resolving the ambiguity of difference phase measurements are:

сигналов

, принимаемых приёмной аппаратурой спутниковой навигационной системы в точках размещения антенн;- total phase differences

signals

received by the receiving equipment of the satellite navigation system at the antenna locations;

от приёмной аппаратуры спутниковой навигационной системы 1;- values of Cartesian coordinates

from the receiving equipment of the satellite navigation system 1;

- values of the coordinates of the place and the components of the linear velocity of the object from the block 6 calculation of navigation parameters;

) от блока 5 вычисления параметров ориентации;- the values of the orientation parameters of the measuring unit 3 of the gimballess inertial measuring module 2 (matrix of guide cosines

) from block 5 calculation of orientation parameters;

- estimates of residual ambiguities of phase measurements from block 7 of the integrated information processing.

расчётных и измеренных значений вторых разностей фаз сигналов

: The output of block 8 for resolving the ambiguity of the difference phase measurements are the differences

calculated and measured values of the second signal phase differences

:

, (3)

, (3)

относительно связанных с измерительного блока 3 осей

, неоднозначности вторых разностей фазовых измерений и шумы измерений. which contain, with corresponding weights, mainly errors in solving a gimballess inertial measuring module 2, orientation tasks of the measuring unit 3, orientation errors of the antenna base

relatively 3 axes connected to the measuring unit

, the ambiguities of the second differences of phase measurements and measurement noise.

– это погрешности

матрицы ориентации, которые однозначно связаны с погрешностями

аналитического построения осей

, где

– погрешность по курсу,

– погрешности построения вертикали места.Orientation errors of the axes of the measuring unit 3 of the gimballess inertial measuring module 2 relative to the geographic accompanying trihedron

Are errors

orientation matrices that are uniquely associated with errors

axes analytical construction

where

- course error

- errors in the construction of the vertical place.

After pre-processing and linearization, as in the prototype [11] and [14], these difference measurements can be approximately written as:

(4)

(four)

– направляющие косинусы вектора антенной базы

в географических осях, т.е. элементы вектора

, (здесь

– известные значения направляющих косинусов вектора антенной базы

в осях измерительного блока 3 – априорная информация); Where

- directing cosines of the antenna base vector

in geographic axes, i.e. vector elements

, (here

- known values of the direction cosines of the antenna base vector

in the axes of the measuring unit 3 - a priori information);

– элементы орта

(направляющие косинусы орта

относительно географических осей);

- elements of orth

(directing cosines of the orth

relative to geographic axes);

– погрешности, обусловленные остаточной неоднозначностью (в пределах длины волны несущей) вторых разностей фазовых измерений для пары спутников

и

;

- errors due to residual ambiguity (within the carrier wavelength) of the second phase measurement differences for a pair of satellites

and

;

– шумы измерений, включающие шумы приёмной аппаратуры спутниковой навигационной системы 1 и составляющие, обусловленные погрешностями знания координат места объекта, эфемеридной информации

и погрешностями привязки вектора антенной базы

к осям измерительного блока 3 бескарданного инерциального измерительного модуля 2.

- measurement noise, including the noise of the receiving equipment of the satellite navigation system 1 and components due to errors in the knowledge of the coordinates of the object’s location, ephemeris information

and errors in the binding of the antenna base vector

to the axes of the measuring unit 3 of the gimballess inertial measuring module 2.

вместе с известными [15] разностными измерениями по навигационным параметрам с выхода блока 8 разрешения неоднозначности разностных фазовых измерений поступают на вход блока 7 комплексной обработки информации для последующей обработки с использованием алгоритмов фильтра Калмана. Measurements

together with the known [15] difference measurements by navigation parameters, the output of block 8 of the ambiguity resolution of the difference phase measurements is fed to the input of the complex information processing unit 7 for subsequent processing using Kalman filter algorithms.

The estimates developed in block 7 of the integrated information processing are fed into feedback (Fig. 1):

измерительного блока 3 бескарданного инерциального измерительного модуля 2 (поступают на один из входов блока вычисления параметров ориентации 5);- for correction of errors of the gimballess inertial measuring module 2 in the development of orientation parameters and compensation of the drift of gyroscopes, as well as the error of the scale factor of the gyroscope installed on the axis

measuring unit 3 of the gimballess inertial measuring module 2 (fed to one of the inputs of the unit for calculating orientation parameters 5);

- for correcting errors of a gimballess inertial measuring module 2 in the development of navigation parameters and errors of accelerometers (fed to one of the inputs of the unit 6 for calculating navigation parameters);

в части их остаточной неоднозначности (поступают на один из входов блока разрешения неоднозначности разностных фазовых измерений 8). В отличие от прототипа модель этих погрешностей фазовых измерений была уточнена и расширена: кроме их описания «скачкообразными» случайными величинами (описание в виде случайных констант) была введена модель, использующая описание в виде соответствующих винеровских процессов с учётом особенностей вращения антенного модуля.- for correction of measurements

in terms of their residual ambiguity (they arrive at one of the inputs of the ambiguity resolution block of difference phase measurements 8). In contrast to the prototype, the model of these phase measurement errors was refined and expanded: in addition to their description by “spasmodic” random variables (description in the form of random constants), a model was introduced that uses the description in the form of the corresponding Wiener processes taking into account the peculiarities of the rotation of the antenna module.

решения задачи ориентации, т.к. коэффициенты

при них носят колебательный характер. Данный факт существенным образом повышает их наблюдаемость на фоне шумов измерений и, следовательно, эффективность используемых измерений. From the analysis of measurements (4) it follows that the rotation of the measuring unit 3 together with the antenna module 9 of the receiving equipment 1 of the satellite navigation system leads to modulation of errors

solving the orientation problem, because odds

with them are oscillatory in nature. This fact significantly increases their observability against the background of measurement noise and, therefore, the effectiveness of the measurements used.

As a result, it is possible (Fig. 2 - Fig. 6), in contrast to the prototype, to ensure the accuracy of the course development at the level of 0.5 ° (P = 0.997) when using the antenna base with the distance between the antennas less than the carrier wavelength. This fact allows to significantly reduce the weight and size characteristics of the antenna module of the integrated orientation and navigation system.

. Для интегрированной системы ориентации и навигации с двумя приёмными аппаратурами спутниковой навигационной системы, возможно получение устойчивого решения только при двух наблюдаемых

, в том числе при запуске системы и отсутствии априорной информации о курсе.In addition, in this case, unlike the prototype, to clarify all the orientation parameters, it is enough to use one antenna base in the antenna module. In addition, in the proposed scheme, a sustainable solution in the development of orientation parameters can be achieved with a significantly smaller (compared to the prototype) quantity

. For an integrated orientation and navigation system with two receiving instruments of the satellite navigation system, it is possible to obtain a sustainable solution only with two observed

, including when starting the system and the absence of a priori information about the course.

In FIG. 2, 3 and 4, the following notation is accepted:

ΔK is the orientation error (degree);

Δθ, ΔΨ - orientation errors at the corners of the rolling and pitching, respectively (deg.);

t is the time in seconds.

In FIG. 5 adopted the following notation:

CDr — MMG drift estimates (CDrGx, CDrGy, CDrGz — drift estimates of the xth, yth, and zth gyroscopes, respectively).

In FIG. 6 the following notation is accepted:

DCf - estimates of the ambiguity of phase measurements (for two pairs of difference phase measurements of second phase differences, illustrating their variability during the experiment).

Analysis of the accuracy of the proposed scheme for building an integrated orientation and navigation system

To prove the operability of the device and assess the accuracy of the proposed solution, a prototype of an integrated orientation and navigation system was developed and bench tests were carried out. The prototype system includes a measuring unit based on STIM 300 micromechanical sensors from Sensonor (Norway) and two receiving equipment of the satellite navigation system 1K-181 from the Russian Institute of Radio Navigation and Time, OJSC with two antennas separated by a transverse axis at 23.5 see. A prototype of the system was installed on a uniaxial table of positioning and rotation, providing rotation with an angular speed of up to 1 Hz and the removal of primary information. The frequency of data acquisition from micromechanical sensors was 1 kHz, and from the receiving modules of the satellite navigation system - 5 Hz.

использовался в качестве опорного).The formation of two pairs of second phase difference differences was carried out using three constantly observed NS GPS (one

used as a reference).

During testing of the measuring unit, the gimballess inertial measuring module was tilted at -41 °  and 1.4 °  on the axes of pitching and rolling, respectively.

To process the difference phase measurements (4), together with the known velocity and positional measurements using the Kalman filter algorithms, the following calculation error model was used.

Calculation model of errors

When forming the calculation model of the errors of the integrated orientation and navigation system, the following approximations were used:

и акселерометров

, изменение систематических составляющих погрешностей масштабных коэффициентов ММГ

от запуска к запуску и их изменчивость в пуске были аппроксимированы (из-за отсутствия достоверных данных об их спектральном составе) соответствующими винеровскими процессами;- displacements of zeros of MMG

and accelerometers

, a change in the systematic components of the errors of the MMG scale factors

from start to start and their variability in start-up were approximated (due to the lack of reliable data on their spectral composition) by the corresponding Wiener processes;

были описаны «скачкообразными» случайными величинами, а также соответствующими винеровскими процессами с учётом особенностей вращения антенного модуля, дисперсия которых восстанавливается до начальной неопределенности при фиксации «скачка» в измерениях

;- errors

were described by “spasmodic” random variables, as well as the corresponding Wiener processes taking into account the rotation characteristics of the antenna module, the dispersion of which is restored to the initial uncertainty when the “jump” in the measurements is fixed

;

аппроксимированы дискретными белыми шумами с известными дисперсиями на частоте формирования измерений.- measurement noise

approximated by discrete white noise with known variances at the measurement frequency.

In this case, the calculated error model of the integrated orientation and navigation system will have the form

(5)

(5)

(6)where the state vector of the system (without taking into account the errors of the reference generator of the receiving equipment of the satellite navigation system) will look like:

(6)

Here

– переходная на шаге

дискретности измерений матрица состояния системы;

- transitional in step

discreteness of measurements system state matrix;

– матрица, определяющая влияние вектора входных шумов

с ковариациями

;

- matrix determining the influence of the input noise vector

with covariances

;

– матрица измерений, соответствующая известным разностным навигационным измерениям и дополнительно уравнениям (4);

- a measurement matrix corresponding to known difference navigation measurements and additionally equations (4);

– погрешности в выработке составляющих вектора относительной линейной скорости объекта в проекциях на географические оси;

– погрешности выработки географических координат места (по широте, долготе и высоте).

- errors in the development of the components of the vector of the relative linear velocity of the object in projections on geographical axes;

- errors in the development of the geographical coordinates of the place (in latitude, longitude and height).

Results of bench tests of a prototype of an integrated orientation and navigation system

The test results are shown in FIG. 2-6.

In FIG. Figure 2 shows the orientation errors when setting the initial error at the rate of the order of 10 °.

In FIG. Figures 3 and 4 show orientation errors when setting the initial error at the 180 ° course, i.e. imitation of the absence of a priori information about the initial value of the course angle (in Fig. 3, the graphs of the variability of errors in orientation parameters are shown in a scale enlarged in time and reduced in error of orientation).

The graphs of FIG. 5 and FIG. 6 are given for the case of setting the initial uncertainty at the 180 ° course.

The results of bench tests of a prototype of the proposed scheme for constructing an integrated orientation and navigation system, shown in the graphs of FIG. 2-6, confirm that with a significant reduction in the length of the antenna base (to the level of the carrier frequency wavelength), while simultaneously monitoring the signals of a limited number of navigation satellites, the accuracy of the heading at 0.5 ° (P = 0.997) is achieved, which seems to be sufficient to ensure the tasks solved by the small-sized devices under consideration.

Thus, the claimed technical result is considered achieved.

Literature

1. krtz.rf / navigation.html

2. RF application No. 98118543.

3. RF patent No. 2215299.

4. RF patent No. 2276384.

5. US Patent No. US2010 / 0117894.

6. www.km.kongsberg.com.

7. Integrated inertial-satellite orientation and navigation system with spaced antennas // Sat. Integrated inertial-satellite navigation systems. - St. Petersburg: publishing house Central Research Institute Electropribor, 2001, pp. 222-229.

8. Integrated satellite and inertial navigation system: experimental results and application to the management of mobile robots // Gyroscopy and navigation, 2007, No. 1 (56), pp. 16-28.

9.rtelecom.ru / catalog / obradio / glonass /3098.php.

10. Stepanov O.A., Koshayev D.A. The study of methods for solving the orientation problem using satellite systems // Gyroscopy and navigation, 1999, No. 2 (25), P. 30-55.

11. RF patent No. 2462690.

12. Stepanov A.P., Ignatiev S.V., Vinokurov I.Yu. et al. On determining the optimal control law of a modulating rotation drive based on minimizing errors of the inertial-satellite system // Materials of the 4th All-Russian Multiconference on Control Problems MKPU-2011. T. 2. - Taganrog: Publishing house of TTI SFU, 2011, S. 316-318

13. A.P. Stepanov, S.V. Ignatiev, I.V. Semyonov Optimal Control of the Modulation Rotation Actuator in a GNSS-aided Inertial System // Volume of 14 Inretnational Student Olympiad on Automatic Control (Baltic Olympiad) SPb, 2011, pp. 141-144.

14. Emelyantsev G.I., Blazhnov B.A., Stepanov A.P. Features of the use of phase measurements in the orientation problem of an integrated inertial-satellite system. The results of sea trials // Gyroscopy and navigation, 2011, No. 3 (74), C. 3-11.

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Claims (33)

1. An integrated inertial-satellite orientation and navigation system containing a gimbal-free inertial measuring module including a measuring unit with at least three gyroscopes and at least three accelerometers and a calculator including an orientation parameter generation unit, a unit development of navigation parameters, a complex information processing unit, a unit for generating and resolving the ambiguity of difference phase measurements, and also containing satellite navigation receiver equipment system, including an antenna module containing at least two antennas spaced on the corresponding antenna base, wherein the complex information processing unit is configured to generate differential measurements by navigation parameters, process information received from the navigation parameters generating unit, the unit for generating and resolving the ambiguity of the differential phase measurements and receiving equipment of satellite navigation systems, the unit for generating and resolving the ambiguity of difference phase measurements is made with the possibility of generating differential phase measurements of the second phase differences and resolving their ambiguity, processing the information received from the unit for generating orientation parameters, the unit for generating navigation parameters, the unit for complex processing of information, and the receiving equipment for satellite navigation systems , while the measuring unit is configured to transmit information about the components of the angular velocity of the object to the input of the block generating orientation parameters, information about the components of linear acceleration of the object to the input of the block generating navigation parameters, the unit for generating orientation parameters is configured to transmit information about the orientation parameters to the unit for generating navigation parameters and to the unit for generating and resolving the ambiguity of difference phase measurements, the unit for generating navigation parameters is configured to transmit information about the coordinates of the place and the components of the linear velocity of the object to the complex information processing unit and to the unit for generating and resolving the ambiguity of the difference phase measurements, complex information processing unit is configured to transmit information: - on the estimates of the errors in the orientation parameters of the measuring unit of the gimballess inertial measuring module in the unit for generating orientation parameters, - on the estimates of the drifts of gyroscopes in the block generating orientation parameters, - about the estimates of the errors of the coordinates of the measuring unit of the gimballess inertial measuring module and the errors of the components of the linear velocity of the object in the block generating navigation parameters, - about the error estimates of the difference phase measurements of the second phase differences in the block for the formation and resolution of the ambiguity of the difference phase measurements, and with the possibility of receiving and processing information about the coordinates of the place and the components of the linear speed of the object coming from the unit for generating navigation parameters, about the measured values of the navigation parameters coming from the receiving equipment of satellite navigation systems, about the measured values of the differences of the second phase differences of the signals of the navigation satellites coming from the unit for generating and resolving the ambiguity of difference phase measurements, the unit for generating and resolving the ambiguity of difference phase measurements is configured to transmit information about the difference phase measurements of the second phase differences to the complex information processing unit and with the possibility of receiving and processing information: - about the complete phase differences of the signals of the navigation satellites, the coordinates of the navigation satellites coming from the receiving equipment of satellite navigation systems, - about the orientation parameters coming from the block generating orientation parameters, - about the coordinates of the place and the components of the linear velocity of the object coming from the block generating navigation parameters, - estimates of errors of difference measurements of the second phase differences of the signals of the navigation satellites coming from the complex information processing unit, characterized in that the gimballess inertial measuring module and antenna module are made with the possibility of rotation relative to the geographic axes in the horizontal plane, and the complex information processing unit and the unit for generating and resolving the ambiguity of difference phase measurements are made with the possibility of processing information from navigation satellite signals of various global satellite navigation systems with code and frequency division signals while the integrated information processing unit is configured to receive and process information: - about the coordinates of the place and the components of the linear velocity of the object from the block generating navigation parameters, - about the measured values of the navigation parameters coming from the receiving equipment of satellite navigation systems, - about the second phase differences of the signals of the navigation satellites from the unit for generating and resolving the ambiguity of the differential phase measurements, moreover, the unit for the formation and resolution of the ambiguity of difference phase measurements is made with the possibility of receiving and processing information: - about the coordinates of the navigation satellites and the measured values of the total phase differences of the signals of the navigation satellites from the receiving equipment of satellite navigation systems, - about the orientation parameters from the block generating orientation parameters, - about the coordinates of the place and the linear speeds of the object from the block generating navigation parameters, - about the errors of the difference measurements of the second phase differences from the complex information processing unit. 2. The integrated inertial-satellite orientation and navigation system according to claim 1, characterized in that the gimballess inertial measuring module is equipped with a drive with an angle sensor configured to provide modulation rotation and measure the rotation angle of the measuring unit around an axis orthogonal to the deck. 3. The integrated inertial-satellite orientation and navigation system according to claim 2, characterized in that the unit for generating orientation parameters is configured to receive information about the angle of rotation of the drive from the angle sensor. 4. The integrated inertial-satellite orientation and navigation system according to claim 2, characterized in that the complex information processing unit is capable of generating and transmitting information about estimating the error of the scale factor of the gyroscope of the measuring unit installed along the rotation axis of the measuring unit. 5. The integrated inertial-satellite orientation and navigation system according to claim 2, characterized in that the complex information processing unit is capable of generating and transmitting information about estimates of location coordinates errors and components of the linear velocity of an object arriving at the input of the navigation parameter calculation unit, information about accelerometer drift estimates received at the input of the navigation parameter calculation unit. 6. The integrated inertial-satellite orientation and navigation system according to claim 2, characterized in that the antenna module of the receiver of satellite navigation systems is rigidly mounted in the axes of the measuring unit of the gimballess inertial measuring unit in a plane parallel to the deck of the object, so that the distance between the antennas less than the carrier wavelength of the satellite signal.

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