CN109945870A - A kind of pseudo satellite, pseudolite indoor orientation method of Pseudo-range Observations and carrier-to-noise ratio fusion - Google Patents
A kind of pseudo satellite, pseudolite indoor orientation method of Pseudo-range Observations and carrier-to-noise ratio fusion Download PDFInfo
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Abstract
The invention discloses the pseudo satellite, pseudolite indoor orientation method that a kind of Pseudo-range Observations and carrier-to-noise ratio merge, include the following steps: that (1) provides positioning equation using weighted mass center location algorithm for asynchronous pseudo satellite, pseudolite indoor locating system；(2) weight is calculated in the pseudo satellite, pseudolite carrier-to-noise ratio value received by receiver；(3) pseudorange and carrier-to-noise ratio observation are merged, increases redundancy observation, is observed the combination of codomain, promotes the precision and reliability of positioning；(4) positioning calculation is carried out using Unscented kalman filtering UKF.The present invention can and multipath error asynchronous to the receiver sampling time have good inhibiting effect, pseudo satellite, pseudolite geometry distribution it is poor in the case where also have good locating effect, show good anti-rough error performance, be suitable for depth indoor scene.
Description
Technical field
The present invention relates to pseudolite systems precision positioning technology field, especially a kind of Pseudo-range Observations and carrier-to-noise ratio fusion
Pseudo satellite, pseudolite indoor orientation method.
Background technique
As location based service (Location Based Service, LBS) is in life and military application
More and more extensive, people are to Global Navigation Satellite System (Global Navigation Satellite System, GNSS)
Application scenarios also proposed more requirements.GNSS is capable of providing continuous reliable high precision position information in free environments,
But it can not solve the problems, such as to block " last one kilometer " to navigate under environment.It is main currently based on the indoor positioning technologies of wireless signal
There are Wi-Fi, bluetooth and ultra wide band (Ultra-Wide Bandwidth, UWB) etc., but WiFi and Bluetooth technology are typically only capable to reach
Meter level positioning accuracy, and establish and safeguard that fingerprint base needs huge workload.Although UWB technology can reach higher precision,
But its signal transmission distance is short, needs accurate clock synchronous, system Construction is expensive, it is difficult to large area deployment and application.
Pseudo satellite technology because its signal cover is wide, signal system is identical as GNSS, can be realized with GNSS indoor and outdoor without
Seam positioning, is just more and more paid attention to, has boundless answer in key area and particular place or even military field
Use prospect.Most mature, the most widely used pseudolite systems of technology are Locata in the world at present, are able to satisfy automatic control, outdoor
The precision positioning demand in the fields such as mining, harbor survey, deformation monitoring inhibits multipath effect by special diversity antenna technology
It answers, the positioning of technical grade, Centimeter Level can be carried out indoors, but Locata system requirements pseudo satellite, pseudolite must keep the stringent time
Synchronous, this requirement to equipment is high, will lead to huge lower deployment cost and enforcement difficulty.Foreign scholar Yun D and Kee C points
It does not have studied synchronous and asynchronous pseudo satellite, pseudolite indoor locating system, and is realized centimetre using carrier phase observation data to millimetre-sized
Positioning accuracy.Borio D in order to evade time synchronization problem, using the weighted mass center method based on Pseudolite signal signal-to-noise ratio into
It has gone indoor positioning experiment, has obtained meter level positioning accuracy.In recent years, domestic scholars have also carried out some rooms based on pseudo satellite, pseudolite
Interior Position Research.GuoX by pseudo satellite, pseudolite shares a crystal oscillator clock, and to realize single poor single-point between the star based on carrier observations fixed
Position, indoor position accuracy reach real-time Centimeter Level.Li X is used based on the THE AMBIGUITY FUNCTION METHOD USED for improving particle swarm algorithm
(Ambiguity Function Method, AFM) carries out single epoch to the fuzziness of indoor pseudo satellite, pseudolite and fixes, and improves tradition
The computational efficiency and search capability of AFM, and realize on single-frequency software receiver the positioning accuracy of indoor pseudo satellite, pseudolite Centimeter Level.
Xu R develops a kind of new pseudo satellite, pseudolite indoor locating system, and transmitter and receiver uses the same clock, and pseudo satellite, pseudolite
Signal can be handled by general purpose receiver, and the simulation experiment result shows that meter level positioning accuracy may be implemented in the system.
The studies above usually has ignored influence of the multipath effect to positioning result, or takes hardware measure (such as helical antenna
Deng) inhibiting multipath error, system cost is excessively high；And for asynchronous pseudo satellite, pseudolite indoor locating system, the receiver sampling time is not
Synchronous bring range error is often also ignored.
Summary of the invention
Technical problem to be solved by the present invention lies in provide the pseudo satellite, pseudolite room of a kind of Pseudo-range Observations and carrier-to-noise ratio fusion
Interior localization method, can and multipath error asynchronous to the receiver sampling time have good inhibiting effect, it is several in pseudo satellite, pseudolite
Also there is good locating effect in the case that distribution is poor, show good anti-rough error performance, is suitable for depth room Nei Chang
Scape.
In order to solve the above technical problems, the present invention provide it is fixed in the pseudo satellite, pseudolite room of a kind of Pseudo-range Observations and carrier-to-noise ratio fusion
Position method, includes the following steps:
(1) positioning equation is provided using weighted mass center location algorithm for asynchronous pseudo satellite, pseudolite indoor locating system；
(2) weight is calculated in the pseudo satellite, pseudolite carrier-to-noise ratio value received by receiver；
(3) pseudorange and carrier-to-noise ratio observation are merged, redundancy observation is increased, is observed the combination of codomain, promotes positioning
Precision and reliability；
(4) positioning calculation is carried out using Unscented kalman filtering (Unscented Kalman Filter, UKF).
Preferably, in step (1), using weighted mass center location algorithm, the position of receiver user can be by following formula meter
It obtains:
In formula, Ppl,iFor the coordinate vector of i-th pseudo satellite, pseudolite；wiFor corresponding weight, the positioning accuracy of system is determined.
Preferably, in step (2), weight is calculated in the pseudo satellite, pseudolite carrier-to-noise ratio value received using receiver, expression
Formula are as follows:
In formula, (C/N0)iFor the signal carrier-to-noise ratio of i-th pseudo satellite, pseudolite.
Preferably, in step (3), asynchronous pseudo satellite, pseudolite indoor positioning observational equation are as follows:
In formula,WithIt is movement/base station to the Pseudo-range Observations of i-th pseudo satellite, pseudolite,WithFor movement/base
Standard is stood to the geometric distance of i-th pseudo satellite, pseudolite,WithFor non-modeling error and observation noise,For double difference operator, simultaneous
Formula (1) and formula (3) obtain new observational equation:
In formula, xu、yu、zuCoordinate as to be solved, υjFor observation noise,R is
Observation noise covariance matrix.
Preferably, it in step (4), is carried out using Unscented kalman filtering (Unscented Kalman Filter, UKF)
Positioning calculation, for systematic procedure noise variance matrix Q and observation noise variance matrix R, due to being static immobilization, Q is set as zero
Matrix, will survey noise variance matrix indicates are as follows:
In formula, γ, η are respectively pseudorange and carrier-to-noise ratio observation noise error matrix, by the statistics for analyzing actual observed value
Characteristic obtains.
The invention has the benefit that in the pseudo satellite, pseudolite room of a kind of Pseudo-range Observations proposed by the present invention and carrier-to-noise ratio fusion
Localization method improves the positioning accuracy of asynchronous pseudo satellite, pseudolite indoor locating system using weighted mass center location algorithm.It is connect by receiver
Weight is calculated in the pseudo satellite, pseudolite carrier-to-noise ratio value received, obtains weighing surely than elevation of satellite in poor signal environment more preferable
Performance.Pseudorange and carrier-to-noise ratio observation are merged, increases redundancy observation, is observed the combination of codomain, promotes the essence of positioning
Degree and reliability.Positioning calculation is carried out using Unscented kalman filtering, without linearizing to observational equation, using determining
Sample point describes the distribution situation of system mode vector estimated value, can weaken the linearized stability of pseudolite positioning.
Detailed description of the invention
Fig. 1 is method flow schematic diagram of the invention.
Fig. 2 is that the present invention tests pseudo satellite, pseudolite and receiver space distribution schematic diagram used.
Fig. 3 is the deviation schematic diagram that the present invention tests pseudorange double difference observation and actual distance used.
Fig. 4 is present invention experiment gained movement station carrier-to-noise ratio measured value schematic diagram.
Fig. 5 is one positioning error sequence contrast schematic diagram of present invention experiment gained experiment.
Fig. 6 is that present invention experiment gained tests two position error alignment's schematic diagrames.
Specific embodiment
As shown in Figure 1, the pseudo satellite, pseudolite indoor orientation method of a kind of Pseudo-range Observations and carrier-to-noise ratio fusion, specific steps are such as
Under:
Step (1), for asynchronous pseudo satellite, pseudolite indoor locating system, using weighted mass center location algorithm, receiver user
Position can be calculated by following formula:
In formula, Ppl,iFor the coordinate vector of i-th pseudo satellite, pseudolite；wiFor corresponding weight, the positioning accuracy of system is determined.
Weight, expression formula is calculated in step (2), the pseudo satellite, pseudolite carrier-to-noise ratio value that receiver receives are as follows:
In formula, (C/N0)iFor the signal carrier-to-noise ratio of i-th pseudo satellite, pseudolite.
Step (3) merges pseudorange and carrier-to-noise ratio observation, increases redundancy observation, asynchronous pseudo satellite, pseudolite indoor positioning observation
Equation are as follows:
In formula,WithIt is movement/base station to the Pseudo-range Observations of i-th pseudo satellite, pseudolite,WithFor movement/
Base station to i-th pseudo satellite, pseudolite geometric distance,WithFor non-modeling error and observation noise,For double difference operator.Connection
Vertical (1) and formula (3) obtain new observational equation:
In formula, xu、yu、zuCoordinate as to be solved, υjFor observation noise,R is
Observation noise covariance matrix.
Step (4) carries out positioning calculation using Unscented kalman filtering (Unscented Kalman Filter, UKF),
For systematic procedure noise variance matrix Q and observation noise variance matrix R, due to being static immobilization, Q is set as null matrix, will survey
Noise variance matrix indicates are as follows:
In formula, γ, η are respectively pseudorange and carrier-to-noise ratio observation noise error matrix, by the statistics for analyzing actual observed value
Characteristic obtains.
For the reliability of verification algorithm, about 20 minutes pseudo satellite, pseudolite static observation data are acquired, data sampling rate is
1Hz has chosen two groups of different data according to the distribution of the geometry of pseudo satellite, pseudolite and carries out indoor positioning resolving, and and conventional mapping methods
It compares.In order to fully assess the performance of location algorithm, experiment one carries out positioning calculation using all 8 pseudo satellite, pseudolites, with true
Protect the distribution of good pseudo satellite, pseudolite geometry and sufficient excess observation component, the spatial distribution of pseudo satellite, pseudolite and receiver is as shown in Fig. 2, room
Interior environment is complex.
Fig. 3 is the pseudorange double difference observation and true pseudo satellite, pseudolite and receiver true geometric distance of u-blox receiver acquisition
Between deviation (reference star be No. 2 pseudo satellite, pseudolites), it can be seen that due to by the sampling time is asynchronous and multipath and indoor letter
The influence of number propagation effect, the quality of pseudorange double difference observation is poor, there is the oscillation and deviation changed over time.Short baseline
Observation error and noise can also be amplified by handling by double difference, this will lead to positioning result substantial deviation true value, or even diverging.
Fig. 4 is the pseudo satellite, pseudolite carrier-to-noise ratio observed quantity of mobile station receiver acquisition, compares pseudorange double difference observation, static observation
Carrier-to-noise ratio it is then relatively stable, be suitable as observation information participate in indoor positioning resolve.But due to receiver surrounding environment change
The signal-to-noise ratio fluctuation range of (such as personnel walk about) and a degree of signal interference, part Pseudolite signal is larger.
The error sequence of positioning result carries out calculating coordinate as shown in figure 5, three kinds of localization methods all use static schema.
By comparison, it can be seen that, using the error minimum of fusion and positioning method, and the stability of positioning result is positioned compared with pseudorange double difference
Very big promotion is obtained.Due to clock drift, the influence of indoor multipath and signal propagation effect, the position error of pseudorange double difference is larger,
And there is slight divergent trend.Good compared with pseudorange double difference using the positioning result of weighted mass center method, reason is that it is more steady
Fixed carrier-to-noise ratio observation output, sufficient pseudo satellite, pseudolite quantity and the distribution of good pseudo satellite, pseudolite.
Table 1 is the positioning result statistics of three kinds of methods, fusion and positioning method it is outer meet, precision of inner coincidence respectively reaches
Decimeter grade and Centimeter Level.With pseudorange double difference positioning compare, Dong Fangxiang, the north to position error respectively reduced 95.0% and
98.5%；Compared to weighted mass center method, Dong Fangxiang, the north to position error respectively reduced 75.4% and 96.5%.
One positioning Comparative result of the experiment of table 1
In order to preferably embody the advantage of this paper algorithm, experiment two has chosen the observation data of 1,2,3,4 and No. 8 pseudo satellite, pseudolite
Indoor positioning resolving is carried out, the geometry distribution of pseudo satellite, pseudolite is poor in the scene.Position error sequence is as shown in fig. 6, can see
It arrives, the positioning result precision obtained using fusion and positioning method is best, and plane error is all within 1m.As shown in table 2, fusion is fixed
Position method it is outer meet, precision of inner coincidence has respectively reached sub-meter grade and the positioning of Centimeter Level and pseudorange double difference is compared, Dong Fangxiang,
The north to position error respectively reduced 55.4% and 81.1%；Compared to weighted mass center method, Dong Fangxiang, the north to positioning
Error has respectively reduced 33.3% and 25.7%.It is by this experiment it can be found that several in pseudo satellite, pseudolite using the method for fusion positioning
Being also obviously improved to positioning accuracy in the case that distribution is poor, therefore to can be suitably used for observing environment poor for this method
Indoor scene, make positioning equation more by increasing new observation information (carrier-to-noise ratio) on the basis of original Pseudo-range Observations
Stablize, effectively inhibit as pseudo satellite, pseudolite geometry be distributed it is bad caused by positioning accuracy decline.
Table 2 tests the comparison of two positioning results
The pseudo satellite, pseudolite indoor orientation method of a kind of Pseudo-range Observations proposed by the present invention and carrier-to-noise ratio fusion, can be to reception
The machine sampling time is asynchronous and multipath error has good inhibiting effect, also has in the case where the distribution of pseudo satellite, pseudolite geometry is poor
Good locating effect shows good anti-rough error performance, is suitable for depth indoor scene.
Claims (5)
1. the pseudo satellite, pseudolite indoor orientation method of a kind of Pseudo-range Observations and carrier-to-noise ratio fusion, which comprises the steps of:
(1) positioning equation is provided using weighted mass center location algorithm for asynchronous pseudo satellite, pseudolite indoor locating system；
(2) weight is calculated in the pseudo satellite, pseudolite carrier-to-noise ratio value received by receiver；
(3) pseudorange and carrier-to-noise ratio observation are merged, increases redundancy observation, is observed the combination of codomain, promotes the essence of positioning
Degree and reliability；
(4) positioning calculation is carried out using Unscented kalman filtering UKF.
2. the pseudo satellite, pseudolite indoor orientation method of Pseudo-range Observations as described in claim 1 and carrier-to-noise ratio fusion, which is characterized in that
In step (1), using weighted mass center location algorithm, the position of receiver user is calculated by following formula:
In formula, Ppl,iFor the coordinate vector of i-th pseudo satellite, pseudolite；wiFor corresponding weight, the positioning accuracy of system is determined.
3. the pseudo satellite, pseudolite indoor orientation method of Pseudo-range Observations as described in claim 1 and carrier-to-noise ratio fusion, which is characterized in that
In step (2), weight, expression formula is calculated in the pseudo satellite, pseudolite carrier-to-noise ratio value received using receiver are as follows:
In formula, (C/N0)iFor the signal carrier-to-noise ratio of i-th pseudo satellite, pseudolite.
4. the pseudo satellite, pseudolite indoor orientation method of Pseudo-range Observations as described in claim 1 and carrier-to-noise ratio fusion, which is characterized in that
In step (3), asynchronous pseudo satellite, pseudolite indoor positioning observational equation are as follows:
In formula,WithIt is movement/base station to the Pseudo-range Observations of i-th pseudo satellite, pseudolite,WithFor movement/benchmark
It stands to the geometric distance of i-th pseudo satellite, pseudolite,WithFor non-modeling error and observation noise,For double difference operator, joint type
(1) and formula (3) obtains new observational equation:
In formula, xu、yu、zuCoordinate as to be solved, υjFor observation noise,R is observation
Noise covariance matrix.
5. the pseudo satellite, pseudolite indoor orientation method of Pseudo-range Observations as described in claim 1 and carrier-to-noise ratio fusion, which is characterized in that
In step (4), positioning calculation is carried out using Unscented kalman filtering UKF, is made an uproar for systematic procedure noise variance matrix Q and observation
Sound variance matrix R, due to being static immobilization, Q is set as null matrix, by survey noise variance matrix expression are as follows:
In formula, γ, η are respectively pseudorange and carrier-to-noise ratio observation noise error matrix, by the statistical property for analyzing actual observed value
It obtains.
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| CN112526562B (en) * | 2020-11-26 | 2022-05-06 | 中国电子科技集团公司第五十四研究所 | PSO particle swarm ranging and positioning method based on L1/B1 double frequency |
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