CN106842260A - A kind of indoor orientation method based on multilayer satellite-signal repeater - Google Patents

Abstract

The invention belongs to electronics, communication and automation field, a kind of indoor orientation method based on multilayer satellite-signal repeater.The present invention is using multilayer satellite-signal repeater repeater satellite signal to interior.Receiver user receives the satellite-signal and the signal from differential reference station of repeated device forwarding simultaneously, the phase that will be measured using repeater satellite signal and the phase measurement row difference operation from base station, to eliminate satellite clock correction, ephemeris error and ionosphere and troposphere delay time error.Then the poor phase measurement of list of the receiver of former and later two epoch and base station is carried out into first difference again to operate to obtain the double-differential carrier phase measured value without fuzziness, it includes user in the position at former and later two moment epoch, and the multinomial value can be obtained using multiple repeaters.It is finally based on these measured values foundation joint equation solution and goes out user in two position coordinateses at moment epoch.The present invention can further improve the precision that indoor positioning is carried out using navigation satellite signal.

Description

Indoor positioning method based on multilayer satellite signal repeater

Technical Field

The invention belongs to the field of electronics, communication and automatic control, and relates to user positioning based on a navigation satellite, in particular to user positioning in a signal blind area of the navigation satellite, such as indoors.

Background

In a navigation satellite signal blind area, such as inside a building or a tunnel, under a viaduct, and the like, a user receiver generally cannot directly acquire a satellite signal, that is, cannot directly calculate a position by using the navigation satellite signal. In this case, if positioning using satellite signals is still needed, the satellite signals are amplified and forwarded by other devices located in good areas of the satellite signals so that users in the blind areas receive valid satellite signals to realize positioning, such as satellite signal repeaters used for indoor positioning. At present, a pseudo-range positioning is mainly adopted in an indoor positioning method based on a signal repeater, the positioning precision is poor, and the measurement error can reach the meter level. Therefore, in order to improve the positioning accuracy, the differential carrier phase method can be adopted to position the indoor users. Aiming at the problem of the integer ambiguity of the differential carrier phase, the problem can be solved by utilizing the change of the geometrical positions of the repeater and the user of two epochs before and after the time, which are caused by the motion of the receiver.

Disclosure of Invention

The invention aims to solve the technical problem of how to improve the indoor positioning accuracy based on navigation satellite signals. The invention relates to an indoor positioning method based on a multilayer satellite signal repeater, which is a method for obtaining accurate position coordinates by an indoor receiver by using navigation satellite signals.

The technical scheme of the invention is as follows:

an indoor positioning method based on a multilayer satellite signal repeater comprises the following steps:

firstly, two or more layers of satellite signal repeaters are deployed at the top or around a building, namely a plurality of repeaters are respectively deployed on two planes (the distance can be meter level) with different altitudes, and the repeaters are utilized to transmit satellite signals. In addition, a differential reference station is deployed near the area to be located (ensuring that the baseline vector is short). The indoor receiver receives signals from nearby differential reference stations in addition to the satellite signals retransmitted by the repeater. The receiver will perform a differential operation using the phase measurements from the transponded satellite signals and the phase measurements from the differential reference station to eliminate satellite clock error, ephemeris error and ionospheric and tropospheric delay errors during the propagation of the satellite signals. The carrier phase measurement value after single difference still contains receiver clock difference, repeater forwarding delay error and phase measurement cycle ambiguity. The round-robin ambiguity of the phase measurements in the previous and subsequent epochs is typically maintained after the receiver locks on to the satellite signal. Thus, the single difference value of the phase measurement between the receivers of the two previous epochs and the differential reference station is subjected to a differential operation again, and a high-precision carrier phase double-difference measurement value without ambiguity can be obtained. Multiple repeaters are used to obtain multiple carrier phase double difference measurements including the position of the user at two epoch times before and after. Thus, by establishing a joint equation based on these measurements, the precise location coordinates of the user at two epoch times can be solved.

The invention has the beneficial effects that:

the user receiver receives the satellite signal forwarded by the repeater and the signal from the differential reference station at the same time, and performs differential operation by using the phase measured by forwarding the satellite signal and the phase measured value from the reference station so as to eliminate satellite clock error, ephemeris error and ionosphere and troposphere delay error. And then carrying out a difference operation on the single difference phase measurement values of the receiver and the reference station of the two previous and next epochs once again to obtain a carrier phase double difference measurement value without ambiguity, wherein the carrier phase double difference measurement value comprises the positions of the user at the time of the two previous and next epochs, and a plurality of items of the carrier phase double difference measurement value can be obtained by using a plurality of repeaters. And finally, establishing a joint equation based on the measurement values to solve the position coordinates of the user at two epoch moments. The invention further improves the accuracy of indoor positioning by using the navigation satellite signals.

Detailed Description

The following further describes the specific embodiments of the present invention in combination with the technical solutions.

An indoor positioning method based on a multilayer satellite signal repeater comprises the following steps:

the navigation satellite signals are respectively transmitted to the indoor through the repeaters on the two layers. When the repeater repeats the signal, in order to facilitate the receiver to identify which repeater the repeated signal comes from, each repeater will delay the signal for a fixed time, the delay time of different repeaters will be different, if the repeater i delays the signal by delta_iIndicates that | Δ is required_i-Δ_j|＞(1+d_c)T_c(i ≠ j), where d_cIs the correlator spacing, T_cIs the chip duration. In addition, the repeater needs to perform certain processing on the satellite signal, so that the carrier phase of the signal after being forwarded by the repeater remains unchanged, that is, the forwarding delay of the repeater and the extra fixed delay have no influence on the phase of the satellite signal.

The indoor receiver measures the phase of the received satellite signal, and the carrier phase measurement of the ith repeater repeat signal can be expressed as

Wherein λ is a carrier wavelength; r is⁽ⁱ⁾Represents the distance of the satellite to the ith repeater; d⁽ⁱ⁾Represents the distance from the ith repeater to the receiver;andrespectively representing the ionospheric and tropospheric delays (in meters) of the satellite s signal to the repeater η the retransmission delay of the satellite signal by the repeater t_uIs the receiver clock error (units are seconds); t is t^(s)Is the satellite clock error (in seconds); delta⁽ⁱ⁾Is a fixed time delay which is artificially added and is a known quantity;represents the cycle ambiguity;representing the receiver measurement noise.

The carrier phase measurements of the differential reference station may be expressed as

Wherein r is_rRepresenting the distance of the satellite from the reference station;andrespectively representing the ionospheric and tropospheric delays (in meters) of the satellite s to the reference station; t is t_rIs the reference station clock error (in seconds); t is t^(s)Is the satellite clock error (in seconds); n is a radical of_rRepresents the cycle ambiguity;_φ,rrepresenting the reference station measurement noise.

The user receiver and the differential reference station are operated differentially (single difference) on the carrier phase measurements of the satellite s-signal, i.e.

Wherein

Equation (3) is a single difference carrier phase measurement equation, whereIs a single difference carrier phase measurement. When the user receiver is relatively close to the differential reference station, equations (4) (5) can be considered equal to 0, i.e., the single difference carrier phase measurement equation eliminates ionospheric and tropospheric errors and satellite clock error. Thus, the formula (3) can be simplified as follows

Single difference carrier phase measurementStill contains receiver clock error, repeater forward delay error and single difference integer ambiguity. After the receiver continues to lock onto the satellite signal, the round-robin ambiguity of the carrier phase measurements in the two epochs before and after the receiver is typically kept constant, and the receiver clock offset and the repeater delay error are also considered to be constant.

Will t_nSingle difference carrier phase measurement at measurement timeIs marked asThen define double difference operation as

Wherein the subscript n represents t_nThe time of day. Distance of satellite to repeater iAnd the distance r of the satellite to the differential reference station_r,nAs is known, in this way, the formula (8) can be further collated as follows

By designating the left part of the equal sign of equation (9) as Y, equation (9) can be written as

Wherein,coordinates, u, of the ith repeater_n＝[x_n,y_n,z_n]Represents t_nAnd M is the number of the repeaters.

The system of nonlinear equations (10) is solved using newton's iteration. Definition of

Wherein,

wherein,similarly, pair y can be found_n-1、z_n-1、y_nAnd z_nThe partial derivatives of (1).

In the kth Newton iteration, each non-linear equation in the equation set (10) may be in [ u [ ]_n-1,k-1,u_n,k-1]Linear (u) of_n-1,k-1＝[x_n-1,k-1,y_n-1,k-1,z_n-1,k-1]^TRepresenting the user position coordinate u at n-1 epoch time_n-1Results at iteration k-1. The linearized matrix equation is

In the formula (14), the compound represented by the formula (I),

wherein,

wherein,

whileTo representFor x_n-1Partial derivatives of (1) in u_n-1,k-1A value of (i) i

To solve the system of equations (14), it is required

M＞＝6 (20)

That is, the number of repeaters is required to be 6 or more. The linearized system of equations can be solved by the least squares method

Thus, the position coordinates of the user receiver at the time of n-1 and n epochs are updated to

When the Newton iteration method converges, the position coordinate [ x ] of the user receiver at n-1 and n epoch time can be obtained_n-1,y_n-1,z_n-1]And [ x ]_n,y_n,z_n]。

Claims (1)

1. An indoor positioning method based on a multilayer satellite signal repeater is characterized by comprising the following steps:

firstly, deploying two or more layers of satellite signal repeaters on the top or around a building, namely deploying a plurality of repeaters on planes with different altitudes, and forwarding navigation satellite signals to the indoor space through the repeaters on the multiple layers; setting the delay time of each repeater to be fixed, if the delay time of each repeater to the signal is different, if the delay time of each repeater to the signal is delta_iIndicates that | Δ is required_i-Δ_j|＞(1+d_c)T_cI ≠ j, where d_cIs the correlator spacing, T_cIs the chip duration;

(1.b) deploying a differential reference station near an area to be positioned, and ensuring that a baseline vector is as short as possible; the differential reference station broadcasts the measured carrier phase and other related information through wireless frequency; the indoor receiver receives the satellite signals forwarded by the repeater and also receives signals from a nearby differential reference station;

(1.c) the indoor receiver measures the phase of the received satellite signal, which represents the carrier phase measurement of the i-th repeater repeat signal as

${\mathrm{\φ}}_u^{\left(i\right)}={\mathrm{\λ}}^{-1}(r^{\left(i\right)}+d^{\left(i\right)}-I_u^{\left(s\right)}+T_u^{\left(s\right)}+\mathrm{\η})+f({\mathrm{\δt}}_u-{\mathrm{\δt}}^{\left(s\right)}+{\mathrm{\Δ}}^{\left(i\right)})+N_u^{\left(i\right)}+{\mathrm{\ϵ}}_{\mathrm{\φ},u}^{\left(i\right)}---\left(1\right)$

Wherein λ is a carrier wavelength; r is⁽ⁱ⁾Represents the distance of the satellite to the ith repeater; d⁽ⁱ⁾Represents the distance from the ith repeater to the user;andrespectively representing ionospheric and tropospheric delays in meters for the satellite s signal to the repeater, η being the repeater's retransmission delay for the satellite signal, t_uIs the receiver clock error in seconds; t is t^(s)Is the satellite clock error in seconds; delta⁽ⁱ⁾Is a fixed time delay which is artificially added and is a known quantity;represents the cycle ambiguity;representing receiver measurement noise;

the carrier phase measurement of the differential reference station is expressed as

${\mathrm{\φ}}_r={\mathrm{\λ}}^{-1}\left(r_r-I_r^{\left(s\right)}+T_r^{\left(s\right)}\right)+f\left({\mathrm{\δt}}_r-{\mathrm{\δt}}^{\left(s\right)}\right)+N_r+{\mathrm{\ϵ}}_{\mathrm{\φ},r}---\left(2\right)$

Wherein r is_rRepresenting the distance of the satellite from the reference station;andrespectively representing ionospheric and tropospheric delays from the satellite s to the reference station in meters; t is t_rIs the reference station clock error in seconds; t is t^(s)Is the satellite clock error inSecond; n is a radical of_rRepresents the cycle ambiguity;_φ,rrepresenting differential reference station measurement noise;

the receiver performs differential operation by using the phase measured by forwarding the satellite signal and the carrier phase measurement value from the differential reference station to eliminate the satellite clock error, the ephemeris error and the ionospheric and tropospheric delay errors in the satellite signal propagation process, i.e. the receiver performs differential operation

${\mathrm{\φ}}_{ur}^{\left(i\right)}={\mathrm{\φ}}_u^{\left(i\right)}-{\mathrm{\φ}}_r={\mathrm{\λ}}^{-1}(r^{\left(i\right)}+d^{\left(i\right)}-r_r-I_{ur}^{\left(s\right)}+T_{ur}^{\left(s\right)}+\mathrm{\η})+f({\mathrm{\δt}}_{ur}+{\mathrm{\Δ}}^{\left(i\right)})+N_{ur}^{\left(i\right)}+{\mathrm{\ϵ}}_{\mathrm{\φ},ur}^{\left(i\right)}---\left(3\right)$

Wherein,is a single difference carrier phase measurement;

$I_{ur}^{\left(s\right)}=I_u^{\left(s\right)}-I_r^{\left(s\right)}---\left(4\right)$

$T_{ur}^{\left(s\right)}=T_u^{\left(s\right)}-T_r^{\left(s\right)}---\left(5\right)$

$N_{ur}^{\left(i\right)}=N_u^{\left(i\right)}-N_r,{\mathrm{\δt}}_{ur}={\mathrm{\δt}}_u-{\mathrm{\δt}}_r,{\mathrm{\ϵ}}_{\mathrm{\φ},ur}^{\left(i\right)}={\mathrm{\ϵ}}_{\mathrm{\φ},u}^{\left(i\right)}-{\mathrm{\ϵ}}_{\mathrm{\φ},r}^{\left(i\right)}---\left(6\right)$

(1, d) when the user receiver is relatively close to the differential reference station, namely the formula (4) (5) is close to 0, the single difference carrier phase measurement equation eliminates ionospheric and tropospheric errors and satellite clock error; the formula (3) is simplified as follows

${\mathrm{\φ}}_{ur}^{\left(i\right)}={\mathrm{\λ}}^{-1}(r^{\left(i\right)}+d^{\left(i\right)}-r_r+\mathrm{\η})+f({\mathrm{\δt}}_{ur}+{\mathrm{\Δ}}^{\left(i\right)})+N_{ur}^{\left(i\right)}+{\mathrm{\ϵ}}_{\mathrm{\φ},ur}^{\left(i\right)}---\left(7\right)$

Single difference carrier phase measurementStill include the receiver clock error, repeater delay error and single difference cycle integer ambiguity;

(1.e) after the receiver continuously locks the satellite signal, the cycle ambiguity of the carrier phase measurement value in the front epoch and the back epoch is kept unchanged, and in addition, the receiver clock error and the repeater delay error are also considered to be unchanged; carrying out a difference operation on the carrier phase single difference measurement values of the receivers of the front epoch and the receiver of the rear epoch and the differential reference station once again to obtain a high-precision carrier phase double difference measurement value without ambiguity; will t_nSingle difference carrier phase measurement at measurement timeIs marked asThen define double difference operation as

${\mathrm{\Δ\φ}}_{ur,n}^{\left(i\right)}={\mathrm{\φ}}_{ur,n}^{\left(i\right)}-{\mathrm{\φ}}_{ur,n-1}^{\left(i\right)}={\mathrm{\λ}}^{-1}(r_n^{\left(i\right)}-r_{n-1}^{\left(i\right)}+d_n^{\left(i\right)}-d_{n-1}^{\left(i\right)}+r_{r,n}-r_{r,n-1})---\left(8\right)$

Wherein the subscript n represents t_nTime of day; distance of satellite to repeater iAnd the distance r of the satellite to the differential reference station_r,nAs is known, the formula (8) is further arranged as follows

$\mathrm{\λ}\·{\mathrm{\Δ\φ}}_{ur,n}^{\left(i\right)}-(r_n^{\left(i\right)}-r_{n-1}^{\left(i\right)}+r_{r,n}-r_{r,n-1})=d_n^{\left(i\right)}-d_{n-1}^{\left(i\right)}---\left(9\right)$

When the left part of the equal sign of formula (9) is denoted as Y, formula (9) is written as

$Y_i=d_n^{\left(i\right)}-d_{n-1}^{\left(i\right)}=\left|\right|R_i-u_n\left|\right|-\left|\right|R_i-u_{n-1}\left|\right|,i=1,2,...,M---\left(10\right)$

Wherein,coordinates, u, of the ith repeater_n＝[x_n,y_n,z_n]Represents t_nThe coordinates of the users at the moment, M is the number of the relays; utilizing a plurality of repeaters to obtain a plurality of carrier phase double-difference measurement values containing positions of users at two epoch moments before and after; establishing a joint equation according to the measurement values, and solving the accurate position coordinates of the user at two epoch moments;

(1.f) solving the nonlinear equation set (10) by Newton's iteration method, defining

$\left[\begin{array}{c}{I}_{x_{n-1}}^{\left(i\right)}\\ I_{y_{n-1}}^{\left(i\right)}\\ I_{z_{n-1}}^{\left(i\right)}\\ I_{x_n}^{\left(i\right)}\\ I_{y_n}^{\left(i\right)}\\ I_{z_n}^{\left(i\right)}\end{array}\right]=\left[\begin{array}{c}\frac{\∂\left(\left|\right|R_i-u_n\left|\right|-\left|\right|R_i-u_{n-1}\left|\right|\right)}{\∂x_{n-1}}\\ \frac{\∂\left(\left|\right|R_i-u_n\left|\right|-\left|\right|R_i-u_{n-1}\left|\right|\right)}{\∂y_{n-1}}\\ \frac{\∂\left(\left|\right|R_i-u_n\left|\right|-\left|\right|R_i-u_{n-1}\left|\right|\right)}{\∂z_{n-1}}\\ -\frac{\∂\left(\left|\right|R_i-u_n\left|\right|-\left|\right|R_i-u_{n-1}\left|\right|\right)}{\∂x_n}\\ -\frac{\∂\left(\left|\right|R_i-u_n\left|\right|-\left|\right|R_i-u_{n-1}\left|\right|\right)}{\∂y_n}\\ -\frac{\∂\left(\left|\right|R_i-u_n\left|\right|-\left|\right|R_i-u_{n-1}\left|\right|\right)}{\∂z_n}\end{array}\right]---\left(11\right)$

Wherein,

$\frac{\∂\left(\left|\right|R_i-u_n\left|\right|-\left|\right|R_i-u_{n-1}\left|\right|\right)}{\∂x_{n-1}}=\frac{x_{R_i}-x_{n-1}}{\sqrt{{\left(x_{R_i}-x_{n-1}\right)}^2+{\left(y_{R_i}-y_{n-1}\right)}^2+{\left(z_{R_i}-z_{n-1}\right)}^2}}=\frac{x_{R_i}-x_{n-1}}{d_{n-1}^{\left(i\right)}}---\left(12\right)$

$\frac{\∂\left(\left|\right|R_i-u_n\left|\right|-\left|\right|R_i-u_{n-1}\left|\right|\right)}{\∂x_n}=\frac{-\left(x_{R_i}-x_n\right)}{\sqrt{{\left(x_{R_i}-x_n\right)}^2+{\left(y_{R_i}-y_n\right)}^2+{\left(z_{R_i}-z_n\right)}^2}}=\frac{-\left(x_{R_i}-x_n\right)}{d_n^{\left(i\right)}}---\left(13\right)$

wherein,similarly, find pairs y_n-1、z_n-1、y_nAnd z_nPartial derivatives of (a); in the kth Newton iteration, each non-linear equation in the equation set (10) is in [ u [ ]_n-1,k-1,u_n,k-1]Linear (u) of_n-1,k-1＝[x_n-1,k-1,y_n-1,k-1,z_n-1,k-1]^TRepresenting the user position coordinate u at n-1 epoch time_n-1The result at the k-1 st iteration; the linearized matrix equation is

$G\left[\begin{array}{c}{\mathrm{\Δx}}_{n-1}\\ {\mathrm{\Δy}}_{n-1}\\ {\mathrm{\Δz}}_{n-1}\\ {\mathrm{\Δx}}_n\\ {\mathrm{\Δy}}_n\\ {\mathrm{\Δz}}_n\end{array}\right]=b---\left(14\right)$

In the formula (14), the compound represented by the formula (I),

$b=\left[\begin{array}{c}{Y}_1-\left(d_n^{\left(1\right)}\left(u_{n,k-1}\right)-d_{n-1}^{\left(1\right)}\left(u_{n-1,k-1}\right)\right)\\ Y_2-\left(d_n^{\left(2\right)}\left(u_{n,k-1}\right)-d_{n-1}^{\left(2\right)}\left(u_{n-1,k-1}\right)\right)\\ \mathrm{...}\\ Y_M-\left(d_n^{\left(M\right)}\left(u_{n,k-1}\right)-d_{n-1}^{\left(M\right)}\left(u_{n-1,k-1}\right)\right)\end{array}\right]---\left(15\right)$

wherein,

$d_n^{\left(i\right)}\left(u_{n,k-1}\right)=\left|\right|R_i-u_{n,k-1}\left|\right|;---\left(16\right)$

$G=\left[\begin{array}{cc}{I}_{u_{n-1}}^{\left(1\right)}\left(u_{n-1,k-1}\right)& -I_{u_n}^{\left(1\right)}\left(u_{n,k-1}\right)\\ I_{u_{n-1}}^{\left(2\right)}\left(u_{n-1,k-1}\right)& -I_{u_n}^{\left(2\right)}\left(u_{n,k-1}\right)\\ \mathrm{...}& \mathrm{...}\\ I_{u_{n-1}}^{\left(M\right)}\left(u_{n-1,k-1}\right)& -I_{u_n}^{\left(M\right)}\left(u_{n,k-1}\right)\end{array}\right]---\left(17\right)$

wherein,

$I_{u_{n-1}}^{\left(i\right)}\left(u_{n-1.k-1}\right)=\left[\begin{array}{ccc}{I}_{x_{n-1}}^{\left(i\right)}\left(u_{n-1,k-1}\right)& I_{y_{n-1}}^{\left(i\right)}\left(u_{n-1,k-1}\right)& I_{z_{n-1}}^{\left(i\right)}\left(u_{n-1,k-1}\right)\end{array}\right]---\left(18\right)$

whileTo representFor x_n-1Partial derivatives of (1) in u_n-1,k-1A value of (i) i

$I_{x_{n-1}}^{\left(i\right)}\left(u_{n-1,k-1}\right)=\frac{x_{R_i}-x_{n-1,k-1}}{\sqrt{{\left(x_{R_i}-x_{n-1,k-1}\right)}^2+{\left(y_{R_i}-y_{n-1,k-1}\right)}^2+{\left(z_{R_i}-z_{n-1,k-1}\right)}^2}}---\left(19\right)$

(1.g) to solve the equation set (14), the requirements are

M＞＝6 (20)

Namely, the number of the repeaters is required to be more than or equal to 6; solving the linearized equation set by using a least square method

$\left[\begin{array}{c}{\mathrm{\Δx}}_{n-1}\\ {\mathrm{\Δy}}_{n-1}\\ {\mathrm{\Δz}}_{n-1}\\ {\mathrm{\Δx}}_n\\ {\mathrm{\Δy}}_n\\ {\mathrm{\Δz}}_n\end{array}\right]={\left(G^{T}G\right)}^{-1}{G}^{T}b---\left(21\right)$

The position coordinates of the user receiver at the time of n-1 and n epochs are updated to

$\left[\begin{array}{c}{u}_{n-1,k}\\ u_{n,k}\end{array}\right]=\left[\begin{array}{c}{u}_{n-1,k-1}\\ u_{n,k-1}\end{array}\right]+\left[\begin{array}{c}{\mathrm{\Δx}}_{n-1}\\ {\mathrm{\Δy}}_{n-1}\\ {\mathrm{\Δz}}_{n-1}\\ {\mathrm{\Δx}}_n\\ {\mathrm{\Δy}}_n\\ {\mathrm{\Δz}}_n\end{array}\right]---\left(22\right)$

When the Newton iteration method converges, the position coordinate [ x ] of the user at the n-1 epoch time and the n epoch time is obtained_n-1,y_n-1,z_n-1]And [ x ]_n,y_n,z_n]。