Method of determining navigation parameters for carrier and hybridisation device associated with kalman filter bank

FIELD: information technology.

SUBSTANCE: method is realised by a hybridisation device comprising a bank of Kalman filters, each working out a hybrid navigation solution from inertial measurements calculated by a virtual platform and raw measurements of signals emitted by a constellation of satellites supplied by a satellite-positioning system (GNSS), and comprises steps of: determination for each satellite of at least one probability ratio between a hypothetical breakdown of given type of the satellite and a hypothetical absence of breakdown of the satellite, declaration of a breakdown of given type on a satellite based on the probability ratio associated with this breakdown and of a threshold value, estimation of the impact of the breakdown declared on each hybrid navigation solution, and correction of hybrid navigation solutions according to the estimation of the impact of the breakdown declared.

EFFECT: determining the type of breakdown.

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The technical field to which the invention relates.

The invention relates to the field of media simultaneously using the information received from the inertial unit and the information obtained from satellite navigation systems such as GPS systems.

The invention concerns a method and device for hybridization and, in particular, fault detection satellites and adjust the impact of such failures.

The level of technology

Media, such as air or sea vessels will be equipped with numerous navigation systems. These systems include, in particular, hybrid-type equipment INS/GNSS (from the English "lnertial Navigation System inertial navigation system and Global Navigation Satellite System (global satellite navigation system)).

Inertial unit outputs information with low noise and high short-term accuracy. However, over long periods of time is the deterioration determining the position of the inertial unit (more or less rapid depending on the quality of sensors, such as accelerometers or gyroscopes, and methods of data processing used in inertial unit). In turn, the information obtained from satellite navigation systems, very little susceptible to deterioration over long periods of time, but the why is often contains a high level of noise and has a variable degree of accuracy. In addition, the data inertial measurements are always available, while information GNSS may not be available or may contain errors and distortions.

Hybridization is the combination of information issued by the inertial unit, with measurements obtained from satellite navigation systems, with the aim of obtaining information about the position and speed using the advantages of both systems. Thus, the accuracy of the measurement data received by the GNSS receiver, allows to compensate the drift of the inertial system, and the results inertial measurement containing a lower level of noise, allow you to filter the noise in the measurements of the GNSS receiver.

Modern navigation systems rely protective volume around the calculated position, including the error of determining the true location in accordance with a specified level of risk to the integrity that defines the degree of system integrity.

In the case of an aircraft such protective volume has the shape of a cylinder that is located vertically relative to the surface of the Earth. Such a cylinder is defined by a radius and height, which are called, respectively, the horizontal protection limit (Horizontal Protection Limit - HPL) and vertical protection limit (Vertical Protection Limit - VPL).

In accordance with the known solutions of the magnitude of HPL and VPL determine, for example, on the ora Kalman filtering, which provides protection against possible failure of the satellite.

Such filters allow hybridization between the information coming from the satellite navigation system, and information received from the inertial unit. One of the filters of the filter set, called the primary filter that uses all measurements GNSS consisting of pseudosmittia and information about their quality. Other filters of the filter set, called auxiliary (secondary), use only a fraction of the available GNSS measurements. In the case of a fault on the level of satellite measurements it does not affect the auxiliary filter that does not receive this dimension: thus, the "pollution" of the specified auxiliary filter does not occur.

Each filter forms a hybrid navigation solution, and the protective radius (horizontal and vertical), corresponding to this solution, and calculated, for example, the covariance associated with the error status, which evaluates the filter. Then on protective limits, which correspond to the solutions generated by each filter of the filter set, define the scope of protection of the HPL and VPL around the true position.

The use of such a set of Kalman filters has been proposed in patent document US7219013. In accordance with this document is m, protective radii calculated using the method of separation of solutions for detecting and eliminating faults satellites using control deviations from expected for Kalman filtering.

However, this architecture does not allow to detect faults due to small drifts, resulting in the need for additional control of deviations from expected for the filters of the so-called method of least squares using only GNSS information.

The applicant has developed a device that uses a set of filters, one example of which is presented in the patent application FR0858726, filed December 17, 2008

The system proposed in this application contains a set of Kalman filters, where each filter is associated with a module adjustment of GNSS measurements at the input of the filter depending on the signal at its output. Hybrid navigation solution is obtained by adjustment of the inertial state in accordance with output signals of the filters included in the filter set.

However, the architecture proposed in this document, is not quite satisfactory. Although it provides the fault detection and exclusion of measurements received from the satellite, which detects a fault, it does not offer any solutions for impact assessment of faults on the Navi is sure solution. Indeed, fault detection based on instantaneous statistical validation, which is produced only when a fault reaches the detection threshold. Thus, even in case of allocation of a faulty satellite navigation solution can not be adjusted, so that there is still a residual error generated by the data that is distorted due to a malfunction prior to its discovery. As a consequence, in case of a malfunction of the satellite, even detected, the protective radius increases significantly.

In the patent application OR the applicant describes a method of determining reliable protective volume in case of a malfunction of the satellite.

The proposed method is based on selecting subsets of the satellites in the composition of the group taking into account the hypothesis the failure to calculate the protective radius of each filter of the filter set. Thus, the integrity risk is distributed between several hypotheses to account for the possible failure of the satellite.

Even if reliable protective scope on it, however, still affected by the failure of the satellites that lead to a significant increase. Thus, the performance of this method can be improved.

In addition, the solution proposed is passed in this field, do not allow to identify the nature of the problem, in particular to distinguish fault types of systematic bias and fault type linear changes, but only allow to detect the presence of one of these faults.

Moreover, because it is not limited to the detection of a fault, there is no guarantee of the absence in a hybrid solution at any time distortions caused by a malfunction, which will be discovered in the future.

Disclosure of inventions

The problem to which the present invention is directed, is to eliminate at least one of the above mentioned disadvantages and, in particular, in reducing the protective radius in case of a malfunction of the satellite.

To solve the problem in accordance with the first aspect of the invention proposes a method of determining the navigation parameters of the media using the hybridization device containing a set (Bank) Kalman filters, each of which forms a hybrid navigation solution based on the inertial measurements calculated by the virtual platform, and the raw measurements of signals transmitted by the satellites and received from a satellite positioning system (GNSS), including the steps are:

determine for each of the satellites, at least one relationship Pravda is dobie between the hypothesis of the presence of satellite malfunction of a particular type and the hypothesis of the lack of satellite malfunction,

ascertain the availability of satellite malfunction of a particular type based on the likelihood ratio corresponding to the malfunction of a particular type, and the threshold value,

assess the impact of a detected failure on each hybrid navigation solutions, and

adjust the hybrid navigation solution in accordance with the assessment of the impact of a detected fault.

Ideally, the method according to the first aspect of the present invention has the following characteristics, which can be implemented individually or in any technically possible combinations:

for each satellite at each iteration of the Kalman filter to determine at least one likelihood ratio in a sliding window of accumulation, and the presence of a fault of a particular type state, if the sum of the relations of the likelihood corresponding to this fault in a sliding window of accumulation exceeds the corresponding threshold value,

in the case of the finding of fault, the method additionally includes the stage at which exclude the raw measurement signals transmitted by satellite, for which the stated problem,

the method additionally includes the stage at which they check and confirm the fault, including the acceptance of the expert validation deviations within a certain period of time after ascertaining the presence of a fault, each deviation reflects the discrepancy between the observation corresponding to the raw measurements obtained from the satellite for which a fault is not detected, and a posteriori evaluation of the specified observation generated by a Kalman filter using raw data obtained from all the satellites of the group, and in case of negative result of this statistical test ascertaining the availability of satellite malfunction cancelled

the method additionally includes the stage at which each satellite is calculated cross-sectional variance and covariance of the cross-variance, reflecting the discrepancy between the observation corresponding to the raw measurements obtained from the satellite, and a posteriori evaluation of the specified observation generated by the Kalman filter, do not use raw measurements coming from the satellite, and the likelihood ratio is determined by the cross-variance and covariance of the cross-variances obtained from the specified Kalman filter that does not use raw measurements coming from the satellite, and to assess the impact of failure of a particular type on the specified cross-sectional deviation,

- impact of failure of a particular type on the specified cross is tkanina assessed by determining according to retrieved from the specified Kalman filter that does not use raw measurements coming from the satellite, the dynamic matrix of variances and evaluation of the amplitude malfunction of a particular type in a sliding window estimates corresponding to a certain number of iterations specified Kalman filter that does not use raw measurements coming from the satellite, and the dynamic matrix of the deviation relates the amplitude malfunction of discrepancies caused a malfunction in the cross-rejection

- specified number of iterations specified Kalman filter corresponds to a period of less than a predetermined detection period,

the amplitude estimation of a fault of a particular type produced in the moving window estimation by minimizing the least squares method or by using the Kalman filter,

- impact assessment of faults on each of the hybrid navigation solution includes determining for each hybrid navigation solution according to the data obtained from the Kalman filter that underlies the hybrid navigation solution, dynamic navigation matrix and the amplitude estimation and covariance faults of a particular type in a sliding window evaluation that corresponds to the specified number of iterations specified Kalman filter, forming a hybrid Navi is sure solution moreover, dynamic navigation matrix relates the amplitude malfunction of discrepancies caused a malfunction in the specified hybrid navigation solution

- for each of the satellites is determined by two likelihood ratio, and one likelihood ratio corresponds to the hypothesis of the presence of a fault type of systematic bias, and the second likelihood ratio corresponds to the hypothesis of the presence of a fault type linear changes

in the case of ascertaining the presence of a fault type of systematic bias at the stage of establishing the stage of evaluation of the impact of faults on each hybrid navigation solution is carried out in a moving window estimation, the beginning of which coincides with the moment of ascertaining the presence of a fault type of systematic bias

in the case of ascertaining the presence of a fault type linear change stage impact assessment of faults on each hybrid navigation solution is carried out in a moving window estimates that precedes the moment of ascertaining the presence of a fault type linear changes, and

- in case of exceeding the several amounts relations likelihood corresponding threshold values at the stage of establishing ascertain the presence of one fault, and this fault corresponds to the Naib is the larger of the amounts relations likelihood.

In accordance with the second aspect of the invention features a hybridization device containing the virtual platform, configured to calculate the inertial measurements, a set of Kalman filters, each of which is designed to generate a hybrid navigation solution based on the inertial measurements and the raw measurements of signals transmitted by the satellites and received from a satellite positioning system (GNSS), and the device includes:

a detection module, configured to determine for each satellite, at least one of the likelihood ratio between the hypothesis of the presence of satellite malfunction of a particular type and the hypothesis of the lack of satellite malfunction, as well as the possibility of ascertaining the presence of a fault of a particular type based on the likelihood ratio corresponding to the malfunction of this type, and the threshold value,

module adaptation, designed to assess the impact of a detected failure on each hybrid navigation solutions generated by the Kalman filter, as well as adjustment of the hybrid navigation solution in accordance with the assessment of the impact of a detected fault.

The solution according to the invention has numerous and benefits.

In particular, the solution according to the invention allows to evaluate the impact of faults on the hybrid navigation solution and to resolve this effect. This provides a more precise determination of the position.

The solution according to the invention also provides detection of slowly developing drifts using statistical tests in a sliding window.

In addition, the solution according to the invention allows to distinguish fault types a systematic offset from the fault type linear changes and to apply corrections corresponding to each type of fault.

In addition, the solution according to the invention facilitates the detection of faults in fewer than a predetermined detection period.

Since each of the auxiliary filter does not use one of the satellites, in the event of failure of the satellite, one of the auxiliary filters are not"contaminated" and preserves the accuracy of the navigation solution.

Hybrid navigation solution generated by each filter of the set, is subjected to correction. This leads to a reduction of the total protection radius.

Brief description of drawings

Other aspects, objectives and advantages of the present invention will become apparent from the following detailed descriptions of preferred options for its implementation, is shown as example, not impose any limitation, with reference to the accompanying drawings. In the drawings:

- figure 1 shows a diagram illustrating one of the possible embodiments of the device according to the second aspect of the invention,

- figa and 2b schematically illustrate the increase of the protective radius in case of failure of the satellite, respectively, when using the known device hybridization and hybridization device according to the second aspect of the invention.

The implementation of the invention

Figure 1 shows the hybridization device 1 in accordance with one of the possible embodiments of the second aspect of the invention, intended for installation in the media, for example, in an aircraft. The hybridization device 1 uses the information received from the inertial unit UMI and from the system GNSS satellite navigation, and includes a virtual platform 2 and the filter set 3 Kalman.

Virtual platform 2 receives inertial increment received from sensors (gyroscopes, accelerometers) inertial unit. Inertial increments correspond, in particular, the angular increments and the increments of speed. Data inertial navigation (such as height, speed or position of the carrier) calculates the virtual platform 2 on the basis of such increments. Such the data inertial navigation in the further description denoted by the term "inertial measurement PPVI".

Such an inertial measurement PPVI transmitted to the evaluation module, a priori estimated pseudoresistance (not represented in figure 1), which also receives position data of the satellites. The module for computing a priori estimated pseudoresistance calculates on the part of the inertial measurements and data on the position of the satellites priori pseudoresistance between the carrier and the satellites visible to the media.

The hybridization device 1 also receives from the system GNSS satellite navigation pseudometerings between the media and a variety of visible satellites. Then, in accordance with known methods, calculate the differences (called observations) between the a priori estimated pseudosolenia and the measurements received from the GNSS system.

The hybridization device 1 further comprises a set of filters 3 Kalman carrying out the hybridization between the inertial data from the inertial unit, and information from a satellite navigation system. Besides giving to the output of statistical information on the measurements, the filter ensures the preservation of the linearity of the virtual platform 2, the model of which is provided by the Kalman filters 3, each of which evaluates the vector dXO-dXn state.

In accordance with the known method the filter set 3 Kalman contains multiple Kalman filters installed is parallel. One of these filters is called the main filter 8 Kalman: it takes into account all observations (getting all the measurements from the GNSS system) and generates the main hybrid navigation solution.

Other filters 8i, 8n called auxiliary filters: each of them takes into account only part of the observations, for example of n-1 observations of n observations corresponding to the n visible satellites, so that the i-th auxiliary filter 8i Kalman receives from the system GNSS measurements for all satellites, except the i-th, and generates the auxiliary hybrid navigation solution.

It should be noted that the above process of forming the observations is not common to all the filters of the filter set 3, but it is carried out for each of the filters. Thus, calculation of the a priori pseudoresistance and the calculation of the above observations are not common to all filters, but the hybridization device 1 according to the invention performs these calculations for each of the filters of the filter set 3.

In the framework of a closed path (architecture with feedback), presented in figure 1, the device 1 hybridization forms a hybrid output signal Xref ("basic navigational data")corresponding to the inertial measurements PPVI calculated by the virtual platform 2 and adjusted using subtractive e is ementa 7 on the vector dC stabilization, the number of components corresponds to the number of components of the state vectors estimated by the Kalman filter.

However, the invention is not limited to such architecture, but also applicable to the architecture of an open path in which subtractive element 7 are not used.

To develop hybrid navigation solutions in the device 1 provides a set of adders 10, each of the adders which is installed on the output of one of the filters set for the addition of vectors dX0-dXn state, formed by the filters, with hybrid output signal Xref.

It should be noted that the hybrid output signal Xref is intended solely for internal use. Thus, the optimal navigation solution is formed by information obtained at the output of the adder 10.

Hybrid output signal Xref can be returned to the input virtual platform 2.

In addition, as shown in figure 1, to the input of each filter of the filter set 3 Kalman may be filed with the vector dC stabilization. Thus, by subtracting from the estimated filters amendments provide dC correction and, consequently, the consistency of filters with a virtual platform 2.

The hybridization device further comprises a module 9 forming vector dC stabilization, two options for the implementation of which is presented below in quality is TBE examples not impose any restrictions.

In accordance with the first of the possible embodiments of the amendments applied to the inertial measurements come from the same filter. Thus, all components of the vector dC stabilization equal to the components of the state vector estimated by the selected Kalman filter. The choice of filter can be implemented, for example, in module 4 in accordance with the patent document ERA, by detecting possible malfunctions of the satellite.

In accordance with a second possible implementation of the vector dC stabilization component-wise form, and for each components use a set of Kalman filtering. This module 9 formation amendments dC made with the possibility of formation of each of the components dC[cocT.] vector dC stabilization as a function of all related components dX0[cocT.]-dXn[cocT.] vectors dX0-dXn correction. The formation of each of the components may be implemented, for example, in accordance with the patent application FR0858721 filed by the applicant on December 17, 2008

In accordance with the embodiment of the invention, represented in figure 1, each filter module is connected 5 correction of satellite measurements, which passes into the filter dimension (usually pseudometerings) system GNSS satellite positioning used filter is after their correction through hybrid navigation solution, formed by the filter. This module 5 correction described in the patent application FR0858726 filed by the applicant on December 17, 2008

In the further description of the faulty satellite believe the satellite, which transmits their messages erroneous information generating divergence (DC or AC) between its actual position and the position specified in the message.

The hybridization device 1 according to the invention contains module 4 detecting and eliminating faults satellites containing module 41 discovery, made with the possibility of implementation stages, in which:

for each satellite to determine at least one ratio Ir, Ir' likelihood between the hypothesis of the presence of satellite malfunction of a particular type and the hypothesis of the lack of satellite malfunction,

in accordance with the ratio of Ir, Ir' likelihood defined for the fault of a particular type, and the threshold value ascertain the availability of satellite malfunction of a specific type.

In the best case scenario for each satellite at each iteration of the Kalman filter in sliding box accumulation determine at least one ratio Ir, Ir' credibility, and the presence of a fault of a particular type state, if the sum of the relations Ir, Ir' likelihood corresponding to t is some fault, in the sliding window exceeds a corresponding threshold value.

A likelihood ratio corresponds to the probability of presence of the corresponding satellite malfunction of a particular type. For example, if the likelihood ratio relating to the malfunction of a particular type, is positive, the probability of such failure from the respective satellite higher. The higher the likelihood ratio, the higher the probability associated with it the fault of the corresponding satellite.

The threshold value may be the same for multiple satellites and/or multiple types of faults; alternatively, the threshold can be different for each satellite and for each type of fault, and in the latter case, each likelihood ratio or, in the best case scenario, each sum relations likelihood, compared with the corresponding threshold values.

The sliding window size savings may vary depending on the type of fault; may also be set by a single sliding window size.

As will be described in detail below, the module 4 detecting and eliminating faults satellites also performs the function of processing and exception GNSS measurements to control.

In the embodiment of the invention, not only nom in figure 1, module 4 detecting and eliminating further comprises a module 42 processing of satellite signals, which receives the GNSS measurements and sends the obtained information in a set of Kalman filter 3 in accordance with the current situation (faulty satellites is not detected, with the exception of satellite data, in which fault).

The hybridization device in accordance with a second aspect of the invention further comprises an adaptation module 5, is arranged to perform the steps where:

assess the impact of a fault on a hybrid navigation solution generated by each Kalman filtering, and

in the case of ascertaining the presence of a fault correct hybrid navigation solution in accordance with the assessment of the impact of the fault.

The adaptation module 5 also performs the function of evaluating differences Δ, ΔXi, ..., ΔXncaused by a problem in the hybrid navigation solutions generated by the filters 8, 8i, ..., 8n Kalman, and adjusting hybrid navigation solutions, for example, by means of a set of subtractive elements 6. However, the present invention is not limited to this architecture, and to assess the impact of a fault on a hybrid navigation solution can be produced by other means, such as Kalman filters, module 41 detected by the program, or any other appropriate means, well-known experts in this field.

Below is a description of the methods of calculation developed by the applicant to determine the relationship of the likelihood and impact of faults on the hybrid navigation solution. These formulae are given as example and does not impose any limitations on the invention.

In the best case scenario, the likelihood ratio is determined by data obtained from Kalman filtering, which contain, in particular, variances and covariances variances, as well as to assess the impact of failure of a particular type of deviation.

The deviation is called the discrepancy between the a priori observation received by the Kalman filter, and a posteriori estimate of such observations generated by the filter.

Thus, each filter generates n deviations, number of satellites in the constellation.

In particular, the so-called deviation is called the variance generated by each of the auxiliary filter 8i Kalman and representing the discrepancy between the a priori observation received from the satellite, from which this auxiliary filter 8i does not receive information and a posteriori evaluation of this observation.

Thus, the set of Kalman filtering produces n∗(n+1) deviations, n of which are cross-tolerance.

In the optimal variant is NTE module 4 detecting and eliminating faults satellites contains the module 40 of the sampling variance, made with the possibility of sampling variance (both cross and not cross) and covariance variance, then sending them to the module 41.

Ideally, the module 40 is configured to transfer the cross-variances or deviations module 41 to calculate the relations of verisimilitude. The advantage of using cross-deviations compared with normal control deviations is that the filter that checks a failing satellite, he does not feel the effects of this failure.

Namely, the i-th auxiliary filter 8i Kalman receives from the system GNSS measurements for all satellites except the i-th and, thus, forms a vector dXi state regardless of Sputnik i, so that this filter 8i does not feel the impact of possible malfunction of the satellite i.

Cross the deviation of the satellite may correspond to, for example, the difference between psevdomasteram to this satellite, certain satellite navigation system, and a posteriori estimate of such pseudoresistance produced by a Kalman filter that does not use pseudoresistance provided by this satellite, which ensures the independence of such assessment from the given satellite. Thus, malfunction, in particular, slow growing, this satellite does not have Liane on the calculation of the likelihood ratio.

It should be clarified that in the General case, the determination of the cross-variances can be applied to any raw measurements, in particular to the measurement of pseudokarst (also called Doppler measurements).

The ratio lr likelihood associated with the malfunction of a certain type for a certain time t is preferably determined by the following formula:

where:

εtthe vector of variances (standard or, in the best case scenario, cross filter 8i Kalman at time t,

St- covariance variance at time t,

ρt"the difference is caused by a malfunction in the vector of deviations at time t.

The symbolTdenotes the transpose of a matrix or vector-columns. The value of ptunknown, but it can be estimated in a moving window estimation. In a preferred embodiment, simultaneously evaluate the generated fault divergence hybrid navigation solution generated by the specified Kalman filter, indicated in the further description of the symbol βt. To obtain these estimates can be used the following formula:

where:

the amplitude estimation of a fault,

φt- dynamic matrix of variances linking amplitude solving is vnesti and divergence, generated fault in the deviation, and

µtdynamic navigation matrix linking the amplitude of the fault and divergence caused by a problem in the hybrid navigation solution.

Ideally, both the dynamic matrix for time t computes module 41 detection based on the data obtained from the specified Kalman filter, preferably cross-recursive way, i.e. for each t φtand µtcalculated by φtand µt

These data, obtained from the Kalman filter can contain the increment of the Kalman filter and transition matrices and observations.

The amplitude estimation of a malfunction in the best case scenario, get in the moving window estimation, which corresponds to a certain number N of iterations of the Kalman filter.

In accordance with an optimum variant of the invention, such an assessment can be obtained by the method of least squares in a sliding window evaluation, preferably by the following formula:

Ideally, a given number N of iterations of the Kalman filter corresponds to a period of less than a predetermined period T of the fault detection. In particular, if the symbol 6 denotes the period of the iteration of the Kalman filter 3, the sliding window evaluation should fell short of the ü the following condition: N·δ≤T.

This sliding window evaluation ideally coincides with a sliding window of accumulation relations likelihood associated with this fault.

The use of such a detection period allows you to limit the size of the moving window, and the burden on computational resources.

In the case of ascertaining the occurrence of a malfunction in the satellite assessment of the differences calculated by the module 5 at time t for each of the hybrid navigation solution generated by the filters 8i Kalman, equal to:

where the value of βtcalculated by the deviation using a priori observation satellites, for which fixed the problem. Module 40 sampling variance optimally configured so that in this case, the transfer module 41 detection and adaptation module 5 only such deviations. Thus, the sampling variance allows to evaluate the impact of faults on the variance using the information transmitted by the satellite, for which detected the fault.

In addition, also estimate the variance covariance R, the error of the hybrid navigation solution generated by the filter 8i Kalman, using the following formula:

where- to the variation of estimates error at time t.

Module 41 of the detection is preferably accumulated relations likelihood for each satellite and each particular type of fault in a sliding window of accumulation.

Calculation of assessments of the impact of faults on the hybrid navigation solution generated by the filters carried out by means of a set of subtractive elements 6. By adding the hybrid output signal by means of a set of adders 10 for each filter 8, 8i, 8n get optimal navigation solution type:

,

the covariance of the error of which is corrected by a value of pi.

Correction, therefore produced at the output of each filter, you can reduce the discrepancy between estimates of provisions formed for each of the filters set, and thus reduce the total protective radius, as shown in figa and 2b.

On figa presents the increase of the horizontal protection limit in case a problem occurs when using a hybridization device according to well-known solutions. The diagram shows the optimal navigation solution X0, X1, Xn and the corresponding limits of protection. Horizontal protection limit around the position X0, calculated by the primary filter, designated as HPL.

It is assumed that the failure of vlee the first satellite of the group. To denote quantities that are affected by the problem, used the designation "[const.]". The first auxiliary filter does not take into account the measurements coming from the faulty satellite; assessment of provisions formed for this filter does not feel the effects of malfunctions and remains unchanged. On the contrary, assess the situation, formed by other filters set, in particular the position X0, change. There is a significant increase in horizontal protection limit.

Increase vertical protection limit can be illustrated by the same schema.

The solution according to the invention allows to significantly limit the increase of the horizontal and vertical limits of protection, and hence the protective volume, in case of any failure by correcting the optimal navigation solutions that are affected by this problem. As shown in fig.2b, the distance between the positions corresponding to the estimates obtained from the different filters is significantly reduced as well? as the scope of protection (HPL or VPL).

In an optimal embodiment of the invention for each satellite define two relations Ir, Ir' credibility, and attitude Ir corresponds to the hypothesis of fault type of systematic bias, and the ratio of Ir' corresponds to the hypothesis of fault type line is con changes.

In particular, the dynamic matrix of the deviations determined for each iteration of the Kalman filter will be different for fault type of systematic bias and fault type linear changes. Consequently, the relationship Ir, Ir' likelihood for each satellite are different.

Thus, the invention allows to distinguish between the occurrence of faults type of systematic bias and fault type linear changes.

In case of malfunction type of systematic bias stage impact assessment of faults on the hybrid navigation solution in the best case scenario is carried out in a moving window estimation, starting from the moment of ascertaining the presence of a fault type of systematic bias. Thus, in case of malfunction type of systematic bias sliding window evaluation leave active for a period of time sufficient for evaluation of the characteristics of the fault.

Ideally, the evaluation of the characteristics of the fault type of systematic bias depends on the moment of occurrence of a fault, i.e. the point at which the sum of the relations of verisimilitude in a sliding window of accumulation corresponding to the fault type of systematic bias, exceeded the corresponding threshold value. Thus the m the exception of the measurement module 42 is injected into effect only after such an assessment.

In case of malfunction type linear changes assess the impact of faults on the hybrid navigation solution is preferably carried out in a sliding window evaluation before ascertaining the availability of fault type linear changes.

In an optimal embodiment, provide the confirmation stage of the exceptions on which the hypothesis of fault check through statistical testing.

Preferrably check, subject to whether the deviation of the primary filter - except for deviations related to the satellite, which detects a fault, within a certain period of time the law of X2. In case of positive result test exception confirm, otherwise, ignore it, and the satellite does not exclude from consideration.

In the best case scenario, if multiple amounts relations Ir, Ir' likelihood exceeds the corresponding threshold, the module 41 detection ascertains the presence of one fault. This fault corresponds to the largest of the amounts relations likelihood for all faults that are detected on all satellites.

Thus, in the case of possible faulty is the child of two satellites confirm only the presence of the most likely faults, and in the case of the possible presence of two different fault types also state that only the presence of the most likely fault.

1. The method of determining the navigation parameters of the media using the hybridization device containing a set of filters (3) Kalman, each of which forms a hybrid navigation solution based on the inertial measurements calculated by the virtual platform (2), and the raw measurements of signals transmitted by the satellites and received from a satellite positioning system (GNSS), characterized in that it comprises the steps that:
determine for each of the satellites, at least one ratio (Ir, Ir') likelihood between the hypothesis of the presence of satellite malfunction of a particular type and the hypothesis of the absence of a satellite fault,
- ascertain the availability of satellite malfunction of a particular type on the basis of relations (Ir, Ir') likelihood corresponding to the malfunction of a particular type, and the threshold value,
- assess the impact of a detected failure on each hybrid navigation solutions, and
- adjust the hybrid navigation solution in accordance with the assessment of the impact of a detected fault.

2. The method according to claim 1, characterized in that for each satellite at each iteration of the Kalman filter is determined, at least one ratio (Ir, Ir') likelihood in a sliding window of accumulation, and the presence of a fault of a particular type state, if the sum of the relations (Ir, Ir') likelihood corresponding to this fault in a sliding window of accumulation exceeds the corresponding threshold value.

3. The method according to claim 2, characterized in that in the case of the finding of fault further includes a stage on which exclude the raw measurement signals transmitted by satellite, for which fixed the problem.

4. The method according to claim 3, characterized in that it further comprises a stage on which to check and confirm the fault, including statistical validation deviations within a certain period of time after ascertaining the presence of a fault, each deviation reflects the discrepancy between the observation corresponding to the raw measurements obtained from the satellite for which a fault is not detected, and a posteriori evaluation of the specified observation generated by a Kalman filter using raw data obtained from all the satellites of the group, and in case of negative result of this statistical test ascertaining the availability of satellite malfunction cancel.

5. The method according to claim 1, great for the present, however, which further includes the step in which for each satellite compute the cross-sectional variance and covariance of the cross-variance, reflecting the discrepancy between the observation corresponding to the raw measurements obtained from the satellite, and a posteriori evaluation of the specified observation generated by the Kalman filter, do not use raw measurements coming from the satellite, and the ratio (Ir, Ir') likelihood is determined by the cross-variance and covariance of the cross-variances obtained from the specified Kalman filter that does not use raw measurements coming from the satellite, and to assess the impact of failure of a particular type on the specified cross-sectional variance.

6. The method according to claim 5, characterized in that the impact of the failure of a certain type on the specified cross-deviation estimate by determining, according to the data obtained from the specified Kalman filter that does not use raw measurements coming from the satellite, the dynamic matrix of variances and evaluation of the amplitude malfunction of a particular type in a sliding window estimates corresponding to a specific number (N) of iterations specified Kalman filter that does not use raw measurements coming from the satellite, and the dynamic matrix of the Devi ations relates the amplitude malfunction of discrepancies, generated by a malfunction in the cross of rejection.

7. The method according to claim 6, characterized in that the specified number (N) of iterations specified Kalman filter corresponds to a period of less than a predetermined time period (T) of the detection.

8. The method according to claim 6, characterized in that the amplitude estimation of a fault of a particular type produced in the moving window estimation by minimizing the least squares method or by using Kalman filter.

9. The method according to claim 1, characterized in that the evaluation of the influence of faults on each of the hybrid navigation solution includes determining for each hybrid navigation solution according to the data obtained from the Kalman filter that underlies the hybrid navigation solution, dynamic navigation matrix and the amplitude estimation and covariance faults of a particular type in a sliding window evaluation that corresponds to the specified number of iterations specified Kalman filter, forming a hybrid navigation solution, and dynamic navigation matrix relates the amplitude malfunction of discrepancies caused a malfunction in the specified hybrid navigation solution.

10. The method according to claim 1, characterized in that each of the satellites define two relations (Ir, Ir') likelihood, and one relation (Ir) likelihood which correspond to the hypothesis of the presence of a fault type of systematic bias, and the second ratio (Ir') likelihood corresponds to the hypothesis of the presence of a fault type linear changes.

11. The method according to claim 10, characterized in that in the case of ascertaining the presence of a fault type of systematic bias at the stage of establishing the stage of evaluation of the impact of faults on each hybrid navigation solution is carried out in a moving window estimation, the beginning of which coincides with the moment of ascertaining the presence of a fault type systematic offset.

12. The method according to claim 10, characterized in that in the case of ascertaining the presence of a fault type linear change stage impact assessment of faults on each hybrid navigation solution is carried out in a moving window estimates that precedes the moment of ascertaining the presence of a fault type linear changes.

13. The method according to claim 2, characterized in that in case of excess of the several amounts relations (Ir, Ir') likelihood corresponding threshold values at the stage of establishing ascertain the presence of one fault, and this fault corresponds to the largest of the amounts relations likelihood.

14. The hybridization device containing the virtual platform (2), is arranged to calculate the inertial measurements, a set of filters (3) Kalman, each of which is intended for creation the hybrid navigation solution based on the inertial measurements and the raw measurement signals, transmitted by the satellites and received from a satellite positioning system (GNSS), characterized in that it contains:
- module (41) of the detection made with the possibility of determining for each satellite, at least one of the relations (Ir, Ir') likelihood between the hypothesis of the presence of satellite malfunction of a particular type and the hypothesis of the lack of satellite malfunction, as well as the possibility of ascertaining the presence of a fault of a particular type on the basis of relations (Ir, Ir') likelihood corresponding to the malfunction of this type, and the threshold value,
- module (5) adaptation, designed to assess the impact of a detected failure on each hybrid navigation solutions generated by the Kalman filters, and adjustment of the hybrid navigation solutions in accordance with the assessment of the impact of a detected fault.



 

Same patents:

FIELD: medicine.

SUBSTANCE: for the purpose of erythrocyte count on blood smear photos, black-and-white photos of blood cells are formed. A Canny edge detector is used to contour the cells. Circles of pre-set diameters are found in the contours by Hough method. Their centres are localised. When forming the photos, the centres of the found circles are distributed. The formed photos are morphologically treated with a close operator, and compact cell count respective to a target erythrocyte count is found.

EFFECT: precision in erythrocyte count on the blood smear photos.

2 cl, 4 dwg

FIELD: physics.

SUBSTANCE: apparatus has a panchromatic optical-electronic unit and a hyperspectral reducer connected in series to an improved device, as well as an improved reconstruction unit in the versions, and within the hyperspectral reducer, series-connected unit for generating spectral zone FRT, unit for orthogonalisation of spectral zone FRT and unit for improved separation of spectrozonal images.

EFFECT: more spectrozontal channels, high spectral selectivity of the channels, spectral resolution of the apparatus and linear resolution of elements of spectrozonal and panchromatic images, obtaining pixel by pixel superposition of images of different spectrozonal channels, reduced complexity of the apparatus.

4 cl, 3 dwg

FIELD: information technology.

SUBSTANCE: device includes: a smoothing unit, a deviation ratio setting subunit, a real deviation subunit, a unit increment subunit, a dynamic characteristic control subunit, a smoothing unit data output, data, first control and clock inputs of the device; a clocking unit for a prediction unit; a prediction unit, a quadratic prediction subunit, a linear prediction subunit, a first derivative estimating unit, having a first subunit for calculating the first derivative, a second subunit for calculating the first derivative; a prediction behaviour control unit, having a register for storing the address of the ordinate of the history of the input process, the input of which is the second control input of the device, a comparator, an inverter, an AND element and an address counter. The prediction unit includes an adaptation unit, having a first and a second XOR element, an OR element, an inverter, a first and a second AND element, a flip-flop and a multiplexer, the output of which is the first data output of the device.

EFFECT: high quality and accuracy of control in digital dynamic control systems.

6 dwg

FIELD: physics, computer engineering.

SUBSTANCE: invention relates to automatic and computer equipment and can be used to predict stationary and non-stationary random processes, increasing quality and accuracy of control in digital systems for controlling and guiding various objects. The prediction unit includes a first derivative estimation unit. The estimation unit has three subunits for calculating first derivatives. The first subunit, which is meant for the first n-th (current) reference point of the history of the predicted process, consists of one adder. The second subunit, which is meant for the second (n-1)-th history reference point, consists of one adder. The third subunit, which is meant for the third (n-2)-th history reference point, consists of two adders and an inverter unit. Outputs of the subunits are the data outputs of the device.

EFFECT: broader functional capabilities by obtaining first derivative estimates for all equidistant points (nodes) of the two-level history of an input smoothed discrete process.

FIELD: physics, computer engineering.

SUBSTANCE: invention relates to digital signal processing and information measuring equipment and can be used to linearise the transform function of units and systems, as well as interpolation and extrapolation of measurement results. The apparatus has an analogue-to-digital converter, an integrator, a unit for calculating sequences of quotients and differences and a unit for calculating parameters of the approximating unit, connected in series, as well as a unit for setting integration intervals, the output of which is connected to the control input of the integrator, and a threshold circuit whose input is connected to the output of the unit for calculating sequences of quotients and differences, and the output is connected to the control input of the unit for calculating sequences of quotients and differences.

EFFECT: high accuracy of approximation.

3 cl, 5 dwg

FIELD: information technology.

SUBSTANCE: apparatus has an input realisation storage unit, a unit for determining quasi-stationarity areas, a mask forming unit, an element-by-element multiplier, an approximation unit, an estimate storage unit, an estimate averaging unit, a useful component estimate storage unit, a current row counter, delay units, an averaging signal generator, a current column counter and a clock pulse generator.

EFFECT: two dimensional estimation of the useful component in conditions with insufficient prior information on statistical characteristics of additive noise and the useful component function.

2 cl, 3 dwg

FIELD: information technology.

SUBSTANCE: invention relates to radio engineering and can be used to filter information processes transmitted using frequency-modulated signals. The method involves prediction of the estimate of the modulating signals on the i-th (i=1, 2,…) extrapolation interval with duration h; determining on that interval the derivative of the reference radio signal dependant on said predicted estimate, synchronously with time sampling of said derivative and the input signal with frequency F>1/h, determining products of their readings; generating a signal on the i-th extrapolation interval which is proportional to the sum of these products; improving the predicted estimate of the modulating signal using said sum; frequency-modulation, using the predicted estimate of the modulating signal, of a pulsed signal which controls sampling of the input signal and the derivative of the reference radio signal.

EFFECT: high processing accuracy owing to adaptive clustering of observations when filtering frequency-modulated signals.

4 dwg

FIELD: information technology.

SUBSTANCE: filter comprises difference units, correction units, adder units, delay circuits, matrix function units, shaping and readout unit of apriori data, regularisation parameter unit.

EFFECT: accuracy of estimating information process parameters in measuring systems.

7 dwg

FIELD: electricity.

SUBSTANCE: electric element having ports and linear electric properties characterised in matrix, which is impedance matrix, admittance matrix or dissipation matrix of electric element and connecting voltage applied to ports with current passing through these ports. Electric element has inactivity determined by means of parameters perturbation up to perturbated set of parameters provided that this perturbated set of parameters corresponds to function in Boolean values.

EFFECT: increase of forecast accuracy for technically relevant linear electric properties of electric elements.

16 cl

FIELD: information technology.

SUBSTANCE: digital predicting and differentiating device includes a unit for estimating first derivatives, having a subunit for calculating a first derivative at a second (n-1)-th reference point of process history consisting of three adders, the output of which is the third data output of the device, and a subunit for calculating a first derivative at the third (n-2)-th reference point of the process history consisting of three adders and a block of inverters, the output of the subunit being the fourth data output of the device.

EFFECT: broader functional capabilities of prediction devices by obtaining estimations of first derivatives using numerical differentiation formulae for prehistory nodes of an input smoothed discrete sequence.

5 dwg, 2 tbl

FIELD: radio engineering, communication.

SUBSTANCE: compound navigation method combines satellite and radar ranging navigation techniques based on ground-based beacons, wherein satellite signals are received both on-board the aircraft and at the row of ground-based beacons, including at ground-based beacons at the landing strip. The ground-based beacons constantly refine base coordinates, determine differential corrections to coordinates and differential corrections to pseudo-ranges, generate a packet of correcting information with said differential corrections, errors in determination thereof, calculated tropospheric refraction data and the refined base coordinates of the ground-based beacons. Based on a request from an aircraft, the ground-based beacon emits, through a distance measurement channel, a signal with correcting information which includes differential corrections only in form of differential corrections to coordinates. The aircraft calculates navigation parameters taking into account correcting information, performs compound data processing and continuous comparative estimation of errors. Upon reaching the aerodrome area and landing, if the error value according to the satellite technique is less, the mode of generating a sequence of request ranging signals of the row of ground-based beacons is switched to a mode for requesting only one ground-based beacon located at the landing strip, wherein on the aircraft, differential corrections in the correcting information are transmitted only in form of differential corrections to pseudo-ranges. Refined coordinates of the aircraft are calculated from the corrected pseudo-ranges.

EFFECT: high reliability and accuracy of determining aircraft coordinates.

9 cl, 2 dwg, 2 app

FIELD: radio engineering, communication.

SUBSTANCE: three-dimensional positioning apparatus (10) with a secondary radar base station (12), designed to measure range to repeaters (14) and has at least one radar antenna (16), has a GNSS receiver (18), designed to measure GNSS signals and has a GNSS receiving antenna (20), an inertial measuring unit (22), designed to determine the position of the GNSS receiving antenna, as well as at least one radar antenna in a common coordinate system relative a zero point, and an integrating processor (24, 30, 31), to which are transmitted psedorange measurements of the GNSS receiver, radar range measurements, and movements of the apparatus relative the axis of the common coordinate system measured by the inertial measuring unit (22), and which determines the three-dimensional position of the common reference point by combining the measurements and data, and arm compensation is carried out based on the measured movements.

EFFECT: high accuracy of positioning.

13 cl, 4 dwg

FIELD: radio engineering, communication.

SUBSTANCE: method comprises the following steps of correcting predictions of a parameter included in a received and time-variable signal: estimation of the prediction error based on a first set of values estimated during a determined time period by comparing these values with values previously predicted for the same determined time period; analysis of the predicted time series of prediction errors by a method of processing the signal and isolating the contributions of the systematic effects, extrapolation of the behaviour of the contributions of the systematic effects during the time period concerned and correction of the predictions using the duly extrapolated values.

EFFECT: correcting prediction of values of time-variable signals subjected to interference by various uncontrollable systematic effects without limitations to existing solutions.

3 cl, 3 dwg

FIELD: radio engineering, communication.

SUBSTANCE: system includes receiving stations (4) for receiving signals transmitted from the spacecraft (6) and a processing station (2) for receiving data from the receiving stations (4), where each receiving station (4) records, during a recording window (8), signals transmitted from the spacecraft (6) and transmits, to the processing station (2), data representing the recorded signals. The recording windows (8) associated with each of the receiving stations (4) are offset and/or have different size with respect to each other. The processing station (2) correlates the recorded signals to estimate the distance difference between the spacecraft (6) and each of a plurality of receiving stations and to estimate the spacecraft (6) position.

EFFECT: avoiding the need to send a reference signal pattern, emission by the spacecraft of any trigger sequence and the need to adapt the spacecraft, and improved estimation of the position of the spacecraft.

22 cl, 10 dwg, 1 tbl

FIELD: radio engineering, communication.

SUBSTANCE: indoor installation transmitter (200-1) is capable of providing position information using a second positioning signal which is compatible with the first positioning signal, which is a spread spectrum signal from each of a plurality of satellites. The indoor installation transmitter (200-1) has EEPROM (243) memory which stores position data for identification of the installation position thereof, FPGA (245) for generating a second signal, which includes position data in form of a spread spectrum signal and a transmitting unit (251-258) for transmitting a spread spectrum signal. The second positioning signal is generated to repeat the same content in a cycle which is shorter than for the first positioning signal.

EFFECT: providing position information without deterioration of accuracy even in a position where it is impossible to receive radio waves from a satellite which emits positioning signals, and shorter time required to obtain position information.

10 cl, 26 dwg

FIELD: radio engineering, communication.

SUBSTANCE: measurement error is detected using statistical estimation based on calculation of residual measurements, which particularly enables, independent of any ground segment (i.e. using a RAIM function), to increase efficiency of the available receiver (designated as "primary") without an integrity monitoring function, detect possible errors which distort input measurements for position calculation owing to use of a robust statistical estimation algorithm, i.e. an algorithm which is not susceptible to measurement errors, and with use of a dynamic criterion, and calculate a robust position adjustment provided by the primary receiver, with exclusion of any such detected error.

EFFECT: protecting a user of a radio navigation receiver from aberrational pseudodistance measurements.

16 cl, 1 dwg

FIELD: radio engineering, communication.

SUBSTANCE: in order to estimate an indication (11) of integrity of the system with respect to location errors (2) of very low probability, lower than or equal to about 10-7, the following steps are carried out in real time: measurement of data calculated by the system; calculation of a model of distribution H of location calculation errors (2) of the system; determination of parameters characterising the distribution model (H); modelling, in the probability domain, of the tail of the distribution H(x) by a calculation means as a function of said parameters applied to the extreme values theory; comparison in real time of the distribution of location errors with a tolerance threshold for providing an indication of integrity; and transmission in real time of the indication (11) of integrity of the system.

EFFECT: solving problems of estimating integrity margin of a satellite navigation system for malfunction events of very low probability.

7 cl, 3 dwg

FIELD: radio engineering, communication.

SUBSTANCE: invention can be used to determine reference location of a base station in a differential global navigation satellite system (GNSS). The base station includes a storage device, a logic controller and a GNSS receiver. Stored reference locations are stored in the storage device in form of sets of coordinates; the GNSS receiver determines the current estimate location of the base station in form of a set of coordinates having components. The logic controller reads the stored reference location and converts components of the stored reference location and components of the current estimate location into a binary string format, after which matching of the current estimate location with the stored reference location is established by establishing matching of the binary string component corresponding to the current estimate location with binary string components corresponding to the stored reference location. If it is established that the stored reference location matches the current estimate location, the stored location is considered the reference location of the base station.

EFFECT: determining the reference location of a base station with high accuracy.

15 cl, 6 dwg

FIELD: radio engineering, communication.

SUBSTANCE: network comprises an aeronautical segment (200) having an aeronautical user segment composed of a plurality of aircraft (2) having on-board radio-frequency receivers (21) capable of measuring delays of the navigation signals transmitted by the satellites (GNSS) and an aeronautical data communication means (5) between the plurality of aircraft (2) and the ground segment (300) in order to transmit measurements to the ground segment (300), and means, at the level of the ground segment (300), of receiving measurements used for calculating said grid, the measurements of delays coming from the plurality of aircraft (2) and from the plurality of ground stations (SBAS G).

EFFECT: high reliability in the communication structure of ionosphere corrections using existing aircraft communication lines directed towards a ground segment, high accuracy of corrections, enabling detection of small ionosphere perturbations, eliminating constraints for coverage of sea areas or mountain areas.

8 cl, 3 dwg

FIELD: radio engineering, communication.

SUBSTANCE: system has a measurement module having a GLONASS/GPS navigation antenna, a GLONASS/GPS navigation receiver, a controller with nonvolatile memory, a transceiving communication module, an accumulator battery, an accumulator battery charging device, sensor equipment for the measurement module, external sensor equipment, a personal computer-based automated operator workstation with a processor.

EFFECT: high accuracy of calculating characteristics of displacements of engineering structures and continuous monitoring of parameters of displacements of engineering structures.

2 dwg

FIELD: instrument making.

SUBSTANCE: result is achieved due to arrangement of elementary photosensitive elements in the space, forming a multi-element photodetector and extraction of information on two angular coordinates of the glowing reference points from their signal values and serial numbers, the value of angular pitch and the angle of inclination of axes of directivity patterns. At the same time the device of the multiple-element photodetector comprises elementary photodetectors arranged with the specified angular pitch relative to a certain axis. The number of elementary photodetectors is at least seven, axes of directivity patterns of elementary photodetectors are arranged at a certain angle different to the straight one and zero one to the axis, relative to which the elementary photodetectors are arranged.

EFFECT: expanded field of view and higher reliability.

3 cl, 7 dwg

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