CN104933845A - Motor train unit key data wireless transmission protection method based on dual-mode navigation system - Google Patents

Abstract

The invention relates to a motor train unit key data wireless transmission protection method based on a dual-mode navigation system, which belongs to the field of a high-speed motor train unit wireless communication protection method. The method comprises the following steps: respectively additionally arranging an AP wireless network and a communication device of a BDS Beidou navigation system for a motor train, respectively transmitting train key data to other motor train units or ground operation dispatching command centers according to bi-directional short messages of a priority sequence of AP wireless network, GPRS network and BDS Beidou navigation system, so that high cost performance and high efficiency of the AP wireless network and the communication advantages of BDS Beidou navigation system can be sufficiently utilized, and the wireless transmission timeliness and reliability of the motor train unit key data can be greatly improved. By adopting the method, data with lower requirement on timeliness is only transmitted by virtue of WIFI of AP wireless network when the motor unit train enters a station or enters a garage, and the data transmission pressure can be alleviated.

Description

Based on the motor train unit critical data wireless transmission support method of double mode navigational system

Technical field

The invention belongs to EMU wireless telecommunications support method field, be specifically related to a kind of motor train unit critical data wireless transmission support method based on double mode navigational system.

Background technology

Train orientation multidate information based on satellite navigation location is one of important information ensureing motor train unit safe operation, except calculate except providing precise positioning, speed to motor train unit and train time service etc. is served, the present position information of head car and trailer is obtained by satnav, can also judge to lift one's head the speed of car and trailer and whether the two spacing changes, whether traffic direction is consistent with speed, confirm the integrality situation in train operation by this.After considering train speed and braking distance, can also determine to set rational safe distance scope respectively before head car He after trailer by calculating, thus make train form the block section of a movement, other vehicle or facility need ensure to be prohibited from entering this block section, to guarantee traffic safety.Moreover, by the electronic chart of train orientation multidate information and Along Railway is integrated, the foundation of the intelligentized control method speed of a motor vehicle can also be provided to train, make train initiatively carry out reduction of speed or speed-raising in advance when the position such as level crossing and bend, avoid the generation of accident and traffic jam.In addition, the speed information that train orientation multidate information comprises is the important evidence judging the current speed per hour of train, vehicle-mounted intelligent control system can be diagnosed and anticipation the current state whether exceeded the speed limit and may exceed the speed limit of train according to this speed information, sends warning in various degree or intelligently adjust train traction and braking control strategy in time to driver.

But, the system of the satellite navigation location that domestic existing acquisition train orientation multidate information relies on is american global positioning system (Global Positioning System, GPS), and the Chinese Beidou satellite navigation system of China's independent research (BeiDouNavigation Satellite System, BDS) then not yet launches application in the real-time location of high ferro motor train unit and related service field.

Except being subject to the potential cost of use of GPS GPS and the constraint of many terms of service, also there is following obviously inferior position in GPS GPS compared with BDS triones navigation system:

First, GPS GPS is the three-dimension navigation system of the unidirectional range finding of passive type pseudo-code, its essence is the positioning system of a unidirectional receiving type, space-based satellite only earthward user send positioning signal, and terrestrial user is after this positioning signal of reception, also need independently resolve oneself current three-dimensional localization coordinate data by terrestrial user by matching unit.Its space-based satellite self can not determine the three-dimensional localization coordinate of this terrestrial user, more cannot send the three-dimensional localization coordinate of this user to other terrestrial user or ground running scheduling command centre, therefore, the station-keeping mode of the unidirectional range finding of this pseudo-code can only make the motor train unit of outfit decoding device try to achieve self position and velocity information in time, but ground running scheduling command centre or other train cannot be made to obtain position and the velocity information of this motor train unit in real time, and this is unfavorable for running scheduling management and guarantee driving safety.

Secondly, signal strength level when arriving receiver antenna input port from satellite launch navigation signal, the minimum guarantee level value of GPS GPS is-130dBm, and the minimum guarantee level value of BDS Beidou satellite navigation system is-133dBm.According to navigator fix and the principle resolved, BDS Beidou satellite navigation system adopts Double-Star Positioning System mode can meet accurate location requirement, GPS GPS then needs the precision of its location of at least four gps satellite guarantees, if gps satellite number deficiency, can not carry out accurate navigator fix.The existing space constellation system of current GPS of America GPS only comprises 21 operational satellites and 3 backup satellites, the satellite in orbit number of triones navigation system reaches 17, the two service quality that can provide is very nearly the same, and plan according to Chinese triones navigation system space constellation, when completing to the year two thousand twenty project, 35 satellites that amount to realizing comprising 5 satellites, 27 Medium Earth-Orbiting Satellites and 3 inclined synchronous orbit satellites are all entered the orbit by triones navigation system.In theory, the number of satellite that ground based terminal navigator can search is located more accurate more at most, this means future, Chinese Beidou navigation satellite in orbit quantity after improving further will exceed and more than GPS of America positioning system, therefore BDS Beidou satellite navigation system positioning signal when the time comes will be stronger, and precision also will be higher.

In addition, GPS GPS only provides coordinate setting service to user, does not but provide any Communications service.And the Beidou satellite navigation system of China's independent research also has the two-way short message communication function not available for GPS of America GPS, it is the first satellite navigation system possessing two-way short message communication and be integrated outside location, time service in the whole world.The two-way short message communication function of Beidou satellite navigation system not only can point-to-point two-way communication, it also supports the broadcasting transmitting of point to multi--point, the Beidou satellite navigation system information group sending function that should communicate based on two-way short message, provides extra facility by giving the overlength distance communication of consumer positioning on the basis of positioning service.Big Dipper short message function additionally provides communication emergency access, this passage no time limit, according to the time interval of setting, constantly can send distress signals.When being in an emergency, user can trigger the emergency relief function in the two-way short message communication function of Beidou satellite navigation system, transmit the information such as present position and disaster-stricken situation to rescue unit in time by satellite navigation terminal equipment, effectively improve rescue search efficiency.

On the other hand, according to the data type of required communication, motor train unit critical data can be divided into two large classes:

The first kind, the data requiring data volume that high but single transmits less to Realtime Capability of Communication, except comprising foregoing train orientation multidate information, this category information also comprises major accident aid request, mobile unit status information, Along Railway facility condition information, level crossing traffic information, schedule information, carrying cargo dead-weight information etc.;

Equations of The Second Kind, other data lower to Realtime Capability of Communication requirement, such as: driving daily record, energy saving optimizing information etc.;

GPRS general packet radio service technology (General Packet Radio Service) is comparatively ripe wireless communication technique, at present, EMU carries out communication by the mobile radio network ground base station such as mounted remote wireless data transmission device and track GPRS or CDMA along the line, and via the transfer of mobile radio network ground base station, in the communication system of final access ground running scheduling command centre, complete the communication process of motor train unit data.Due to mobile radio network ground base stations such as current GPRS, in the whole nation, most region realizes all standing, therefore by its comparatively stable wireless signal covering network and efficient data movement capacity, the transmission of the above-mentioned motor train unit critical data comprising video information can be met.

But existing motor train unit critical data transfer approach is seriously and the ground base station system solely depending on the mobile radio networks such as GPRS and spread all over the country, even the train orientation multidate information such as the motor train unit three-dimensional localization coordinate data resolving and obtain by GPS GPS and speed data also all need to depend on the mobile radio networks such as GPRS could transfer send other motor train unit or ground running scheduling command centre to.

Because Beidou satellite navigation system not yet launches application in the real-time location of high ferro motor train unit and related service field, therefore, once train need desert, remote mountain areas or because of calamity impaired etc. there is no the environment of GPRS class mobile radio network quorum sensing inhibitor under run, then will there is risk hidden danger in the security of operation of motor train unit, the management and running work of ground running scheduling command centre also cannot be carried out, if train meets with dangers in the case, more execute the work of helping to search and rescue and will constitute a serious difficulty and challenge.Simultaneously, depend on merely the train orientation multidate information obtain manner of GPS of America positioning system, not only be limited by its potential usage charges and the constraint of many terms of service, more exist positioning precision and cost performance all gradually by Beidou satellite navigation system the development problem of catching up with and surpassing.

Another situation about receiving much concern is, existing motor train unit train also because realizing having both and switching of GPS of America GPS or Chinese Beidou satellite navigation system, and can not adapt to the growth requirement that China high ferro exports other country.

In addition, the new wireless networks of the technology such as such as WiFi (Wireless Fidelity) Wireless Fidelity has developed rapidly since in recent years, and a collection of novel access node AP based on 8011.11b communication standard (Access Point) the class wireless network being Typical Representative with WiFi wireless network is more and more widely used in the various public arenas such as railway station.The area coverage of this type of AP wireless network is far away from mobile radio networks such as GPRS, but the AP equipment in coverage can enjoy higher data transmission efficiency with cheaper price by AP wireless network Luoque, therefore, in local coverage, AP wireless network has higher cost performance and convenience than GPRS class mobile radio network, is a mature technology with application advantage and prospect.But there is no widespread use at motor train unit critical data field of wireless transmission AP wireless network.

On the other hand, existing satnav principle is as follows:

One, the calculating coordinate formula of GPS navigation location is:

The pseudorange R that vehicle-mounted terminal equipment records from i satellite _ican be expressed as:

R _i＝c△t _i(1)

Formula (1), middle c represents satellite signal transit speed, △ t _irepresent that terminal device receives current time and the difference of satellite transmitted signal time of satellite-signal;

By pseudorange R _ithe formula being converted into three-dimensional coordinate is:

$R_i=\sqrt{{(X-X_i)}^2+{(Y-Y_i)}^2+{(Z-Z_i)}^2}---\left(2\right)$

In formula (2), X _i, Y _i, Z _irepresent the volume coordinate of i-th satellite, X, Y, Z represent the locus of subscriber terminal equipment.

Jointly form GPS positioning equation group by formula (1) and formula (2), GPS positioning equation group has four unknown quantity X, Y, Z, △ t _i, solve this four unknown quantitys, four independently equations must be set up, this means the signal at least needing four satellites with this distance-measuring and positioning method.

Two, the Double-Star Positioning System principle of triones navigation system is as follows:

Beidou navigation positioning principle as shown in Figure 1, defines and measures two time delays:

Send interrogating signal from ground running scheduling command centre and be forwarded to subscriber terminal equipment to a certain big-dipper satellite S0; Subscriber terminal equipment sends location response signal is forwarded back to ground running scheduling command centre again time delay gauge work through same satellite S0: the first retardation t _b1;

From ground, running scheduling command centre sends interrogating signal, subscriber terminal equipment is arrived through above-mentioned same satellite S0, subscriber terminal equipment sends response signal, then is forwarded back to the time delay gauge work of ground running scheduling command centre through another satellite S1: the second retardation t _b2;

Then Big Dipper positioning equation group can be expressed as:

When vehicle-mounted user terminal only can detect the signal of a big-dipper satellite S0, only measure the first retardation t _b1, by the first retardation t _b1with signal at satellite S0 place's transfer t consuming time _s0mistiming meter make △ t _b1, the volume coordinate meter of satellite S0 is X ₀, Y ₀, Z ₀, and then list Big Dipper positioning equation group:

2(R _S0+R ₀)＝c△t _B1(3)

$R_0=\sqrt{{(X-X_0)}^2+{(Y-Y_0)}^2+{(Z-Z_0)}^2}---\left(4\right)$

In formula (4), the three-dimensional coordinate of vehicle-mounted user terminal is (X, Y, Z), coordinate figure (X ₀, Y ₀, Z ₀) be big-dipper satellite 3 d space coordinate;

When vehicle-mounted user terminal detects the signal of another big-dipper satellite S1, then by the second retardation t _b2with signal at satellite S0 and S1 place transfer t consuming time _s12mistiming meter make △ t _b2, the volume coordinate meter of satellite S1 is X _s1, Y _s1, Z _s1, then can obtain two other equation:

R _S0+R ₀+R+R _S1＝c△t _B2(5)

$R=\sqrt{{(X-X_{S1})}^2+{(Y-Y_{S1})}^2+{(Z-Z_{S1})}^2}---\left(6\right)$

In formula (5), R _s0for ground running scheduling command centre is to the distance of big-dipper satellite S0, this distance R _s0be known quantity, the product sending to big-dipper satellite S0 the time interval and satellite signal transit speed c that interrogating signal receives signal to satellite S0 by ground running scheduling command centre is tried to achieve; R _s1for ground running scheduling command centre is to the distance of big-dipper satellite S1, this distance R _s1be known quantity, the product sending the time interval and satellite signal transit speed c that response signal receives signal to ground running scheduling command centre by big-dipper satellite S1 is tried to achieve; Height value Z is also known quantity, and it obtains in conjunction with the digitalized electron map inquiry of Along Railway by ground running scheduling command centre.

R ₀represent the distance of big-dipper satellite S0 to vehicle-mounted subscriber terminal equipment; R represents the distance of big-dipper satellite S1 to subscriber terminal equipment.

From geometric relationship, subscriber terminal equipment subpoint on vertical height be in one with S0 be the centre of sphere a sphere and with on the common intersection of two spheres of two satellites S0, S1 ellipsoid that is focus.In addition, because the three-dimensional coordinate of ground running scheduling command centre and two satellites is all known, the transfer communication response time between the height value Z of vehicle-mounted user terminal, ground control control center and each satellite or mobile unit is also all known quantity; Therefore, two retardations can be tried to achieve respectively by above-mentioned known quantity and calculate the distance R of user to first satellite S0 ₀, and user is to the distance sum R of two satellites ₀+ R.And then triones navigation system only Big Dipper positioning equation group (3) namely by Double-Star Positioning System under the prerequisite of acquisition two Big Dipper satellite signals, (4), (5), (6) need can extrapolate the three-dimensional coordinate (X, Y, Z) of user terminal.

In summary, the three-dimensional coordinate (X, Y, Z) obtaining vehicle-mounted user terminal all independently can be resolved with GPS positioning equation group (1), (2) in Big Dipper positioning equation group (3), (4), (5), (6), and three-dimensional system of coordinate both it and unit all can be general.The three-dimensional coordinate (X, Y, Z) of vehicle-mounted user terminal is the three-dimensional coordinate of motor train unit.

Cramer's rule (Cramer's Rule) be in linear algebra one about the known theorem solving system of linear equations.

Summary of the invention

In order to solve existing motor train unit critical data transfer approach seriously and the ground base station system solely depending on the mobile radio networks such as GPRS and spread all over the country, once train runs under the environment not having GPRS class mobile radio network quorum sensing inhibitor, then any information cannot be sent to other motor train unit or ground running scheduling command centre; Current motor train unit depends on merely GPS of America positioning system but not Chinese Beidou satellite navigation system, GPS of America global positioning system cannot be realized unify having both and switching of Beidou satellite navigation system, also motor train unit industry development demand cannot be met, and ripe AP radio network technique is not yet able to the technical matters of widespread use in motor train unit critical data field of wireless transmission, the invention provides a kind of motor train unit critical data wireless transmission support method based on double mode navigational system.

The technical scheme that technical solution problem of the present invention is taked is as follows:

Based on the motor train unit critical data wireless transmission support method of double mode navigational system, it comprises the steps:

Step one: for motor train unit train installs teledata radio transmitting device, this device possesses GPS navigation positioning function, BDS Beidou navigation positioning function, GPRS mobile radio network and AP wireless network data passage and debugs respectively, makes it all can work alone;

Step 2: judge the signal strength indicator of current AP wireless network whether >=preset value, if then perform step 3, otherwise, perform step 4;

Step 3: the vehicle communications device enabling AP wireless network connects with the AP wireless network uphole equipment of Along Railway, and by the transfer of AP wireless network, running scheduling command centre transmits whole two class motor train unit critical datas earthward, then performs step 4;

Step 4: judge the signal index of the mobile radio networks such as current GPRS whether >=preset value, if so, then perform step 5, otherwise, perform step 6;

Step 5: adopt the mobile radio networks such as GPRS to carry out the transmission of first kind motor train unit critical data, and re-execute step 2;

Step 6: judge the performance index of the signal of BDS triones navigation system whether >=performance index of the signal of GPS GPS, and car antenna terminal device at least can detect that two intensity are greater than the Big Dipper satellite signal of-133dBm simultaneously, if, then perform step 7, otherwise directly perform step 9;

Step 7: adopt the two-way short message communication function transmission of BDS triones navigation system not comprise all the other whole first kind motor train unit critical datas of train orientation multidate information, then perform step 8;

Step 8: directly adopt BDS triones navigation system to obtain train orientation multidate information, and by the two-way short message communication function of BDS triones navigation system by this train orientation dynamic message transmission to ground running scheduling command centre and other motor train unit, then re-execute step 2;

Step 9: use the multidate information that GPS GPS obtains train orientation instead, it specifically comprises following sub-step:

Step 9.1: judge whether car antenna terminal can detect that at least four signal intensities are greater than the gps satellite signal of-130dBm, if so, then perform step 10 simultaneously, otherwise, perform step 9.2;

Step 9.2: judge whether car antenna terminal can detect that at least two signal intensities are greater than the gps satellite signal of-130dBm simultaneously, and can also detect that at least one signal intensity is greater than the Big Dipper satellite signal of-133dBm simultaneously, if, then perform step 11, otherwise, perform step 9.3;

Step 9.3: abandon this satnav and communication, and after three minutes, re-execute step 2 in time delay;

Step 10: only adopt the train orientation multidate information of GPS GPS to current motor train unit self to carry out independently resolving and storing, then re-execute step 2;

Step 11: the train orientation multidate information adopting big-dipper satellite and gps satellite hybrid navigation location technology to obtain current motor train unit self carries out independently resolving and storing, and then re-executes step 2;

As described in step 6, the performance index of the signal of navigational system are the weighted mean value of detection probability, false alarm rate, mean acquisition time three indexs.

The concrete scheme that employing big-dipper satellite described in step 11 and gps satellite hybrid navigation are located comprises the steps:

Step 11.1: judge whether simultaneously can detect that three signal intensities are greater than the gps satellite signal of-130dBm by car antenna terminal described in step 9.2, and can also detect that at least one signal intensity is greater than the Big Dipper satellite signal of-133dBm simultaneously, if then perform step 11.2, otherwise, perform step 11.7;

Step 11.2: by Big Dipper positioning equation group with become GPS positioning equation group and combine, form the first complementation and resolve system of equations, to resolve the three-dimensional coordinate (X, Y, Z) of current motor train unit self:

$\left\{\begin{array}{c}2(R_{S0}+R_0)={\mathrm{c\Δt}}_{B1}\\ R_0=\sqrt{{(X-X_0)}^2+{(Y-Y_0)}^2+{(Z-Z_0)}^2}\\ R_i={\mathrm{c\Δt}}_i\\ R_i=\sqrt{{(X-X_i)}^2+{(Y-Y_i)}^2+{(Z-Z_i)}^2}\end{array}\right.---\left(7\right)$

In formula (7), R _s0for ground running scheduling command centre is to the distance of big-dipper satellite S0, S0 is known quantity; Constant c represents satellite signal transit speed, is also known quantity; Coordinate figure (X ₀, Y ₀, Z ₀) be big-dipper satellite 3 d space coordinate, and coordinate figure (X _i, Y _i, Z _i) wherein i=1,2,3 represent the 3 d space coordinate of three gps satellites respectively; The spatial value of above-mentioned four satellites is all the known quantities that can obtain at any time;

In variable to be solved, △ t _b1represent the first retardation t _b1to expend time in t in satellite S0 place's transfer with signal _s0mistiming; △ t _irepresent that terminal device receives the time of gps satellite signal and the difference of satellite transmitted signal time; (X, Y, Z) is train D coordinates value to be solved;

Step 11.3: directly formula (7) is launched to be transformed to by application carat method of writing from memory:

$\left\{\begin{array}{cc}{(X-X_0)}^2+{(Y-Y_0)}^2+{(Z-Z_0)}^2={(\frac{1}{2}{\mathrm{c\Δt}}_{B1}-R_{S0})}^2=R_0^2& \left(a\right)\\ {(X-X_1)}^2+{(Y-Y_1)}^2+{(Z-Z_1)}^2={\left({\mathrm{c\Δt}}_1\right)}^2=R_1^2& \left(b\right)\\ {(X-X_2)}^2+{(Y-Y_2)}^2+{(Z-Z_2)}^2={\left({\mathrm{c\Δt}}_3\right)}^2=R_2^2& \left(c\right)\\ {(X-X_3)}^2+{(Y-Y_3)}^2+{(Z-Z_3)}^2={\left({\mathrm{c\Δt}}_3\right)}^2=R_3^2& \left(d\right)\end{array}\right.---\left(8\right)$

Step 11.4: arrange formula (8), does difference with formula (b), formula (c) and formula (d) respectively by formula (a), then can obtain three new system of equations:

$\left\{\begin{array}{c}({2X}_1-{2X}_0)X+({2Y}_1-{2Y}_0)Y+({2Z}_1-{2Z}_0)Z=R_1^2-R_0^2+X_1^2+Y_1^2+Z_1^2-X_0^2-Y_0^2-Z_0^2\\ ({2X}_2-{2X}_0)X+({2Y}_2-{2Y}_0)Y+({2Z}_2-{2Z}_0)Z=R_2^2-R_0^2+X_2^2+Y_2^2+Z_2^2-X_0^2-Y_0^2-Z_0^2\\ ({2X}_3-{2X}_0)X+({2Y}_3-{2Y}_0)Y+({2Z}_3-{2Z}_0)Z=R_3^2-R_0^2+X_3^2+Y_3^2+Z_3^2-X_0^2-Y_0^2-Z_0^2\end{array}\right.$

Step 11.5: above formula is written as Cramer's rule form:

$\left\{\begin{array}{c}{a}_{11}X+a_{12}Y+a_{13}Z=b_1\\ a_{21}X+a_{22}Y+a_{33}Z=b_2\\ a_{31}X+a_{32}Y+a_{33}Z=b_3\end{array}\right.---\left(9\right)$

In formula (9), a _mn(m, n are natural number) is matrix coefficient;

Step 11.6: application Cramer's rule, then the train D coordinates value (X, Y, Z) solved:

$X=\frac{\left|\begin{array}{ccc}{b}_1& a_{12}& a_{13}\\ b_2& a_{22}& a_{23}\\ b_3& a_{32}& a_{33}\end{array}\right|}{\left|\begin{array}{ccc}{a}_{11}& a_{12}& a_{13}\\ a_{21}& a_{22}& a_{23}\\ a_{31}& a_{32}& a_{33}\end{array}\right|},Y=\frac{\left|\begin{array}{ccc}{a}_{11}& b_1& a_{13}\\ a_{21}& b_2& a_{23}\\ a_{31}& b_3& a_{33}\end{array}\right|}{\left|\begin{array}{ccc}{a}_{11}& a_{12}& a_{13}\\ a_{21}& a_{22}& a_{23}\\ a_{31}& a_{32}& a_{33}\end{array}\right|},Z=\frac{\left|\begin{array}{ccc}{a}_{11}& a_{12}& b_1\\ a_{21}& a_{22}& b_2\\ a_{31}& a_{32}& b_3\end{array}\right|}{\left|\begin{array}{ccc}{a}_{11}& a_{12}& a_{13}\\ a_{21}& a_{22}& a_{23}\\ a_{31}& a_{32}& a_{33}\end{array}\right|}$

Try to achieve the three-dimensional coordinate that coordinate figure (X, Y, Z) is current motor train unit car antenna terminal device self;

Step 11.7: judge whether only simultaneously can detect that two signal intensities are greater than the gps satellite signal of-130dBm by the car antenna terminal described in step 9.2, and can also detect that at least one signal intensity is greater than the Big Dipper satellite signal of-133dBm simultaneously, if, then perform step 11.8, otherwise, abandon this satnav and communication, and after three minutes, re-execute step 2 in time delay;

Step 11.8: by Big Dipper positioning equation group with become GPS positioning equation group and combine, form the second complementation and resolve system of equations, to resolve two-dimensional coordinate (X, Y) value of current motor train unit self:

$\left\{\begin{array}{c}2(R_{S0}+R_0)={\mathrm{c\Δt}}_{B1}\\ R_0=\sqrt{{(X-X_0)}^2+{(Y-Y_0)}^2}\\ R_i={\mathrm{c\Δt}}_i\\ R_i=\sqrt{{(X-X_i)}^2+{(Y-Y_i)}^2}\end{array}\right.---\left(10\right)$

Each parameter implication in formula (10) is all identical with the solution procedure that system of equations is resolved in the first complementation with method for solving, but only has two, gps satellite coordinate figure (X in this system of equations due to gps satellite signal _i, Y _i, Z _i) in i can only be 1 or 2, and coordinate figure i=1,2 represent the 3 d space coordinate of two gps satellites respectively, its solution process is as follows:

Step 11.9: directly formula (10) is launched to be transformed to by application carat method of writing from memory:

$\left\{\begin{array}{cc}{(X-X_0)}^2+{(Y-Y_0)}^2={(\frac{1}{2}{\mathrm{c\Δt}}_{B1}-R_{S0})}^2=R_0^2& \left(a\right)\\ {(X-X_1)}^2+{(Y-Y_1)}^2={\left({\mathrm{c\Δt}}_1\right)}^2=R_1^2& \left(b\right)\\ {(X-X_2)}^2+{(Y-Y_2)}^2={\left({\mathrm{c\Δt}}_3\right)}^2=R_2^2& \left(c\right)\end{array}\right.---\left(11\right)$

Step 11.10: arrange formula (11), does difference with formula (b), formula (c) respectively by formula (a), then can obtain three new system of equations:

$\left\{\begin{array}{c}({2X}_1-{2X}_0)X+({2Y}_1-{2Y}_0)Y=R_1^2-R_0^2+X_1^2+Y_1^2-X_0^2-Y_0^2\\ ({2X}_2-{2X}_0)X+({2Y}_2-{2Y}_0)Y=R_2^2-R_0^2+X_2^2+Y_2^2-X_0^2-Y_0^2\end{array}\right.$

Step 11.11: above formula is written as Cramer's rule form:

$\left\{\begin{array}{c}{a}_{11}X+a_{12}Y=b_1\\ a_{21}X+a_{22}Y=b_2\end{array}\right.---\left(12\right)$

In formula (12), a _mn(m, n are natural number) is matrix coefficient;

Step 11.12: application Cramer's rule, then the train D coordinates value (X, Y) solved:

$X=\frac{\left|\begin{array}{cc}{b}_1& a_{12}\\ b_2& a_{22}\end{array}\right|}{\left|\begin{array}{cc}{a}_{11}& a_{12}\\ a_{21}& a_{22}\end{array}\right|},Y=\frac{\left|\begin{array}{cc}{a}_{11}& b_1\\ a_{12}& b_2\end{array}\right|}{\left|\begin{array}{cc}{a}_{11}& a_{12}\\ a_{21}& a_{22}\end{array}\right|},$

Try to achieve the two-dimensional coordinate that coordinate figure (X, Y) is current motor train unit car antenna terminal device self;

Step 11.13: train two-dimensional coordinate value (X, Y) the theoretical height value Z that this coordinate figure of digitalized electron map inquiry is current along the railway that the ground running scheduling command centre of big-dipper satellite tries to achieve according to step 11.12, thus also can calculate 3 d space coordinate.

The invention has the beneficial effects as follows: the method overcome the single and undue problem relying on GPRS mobile communications network of existing train of high-speed motor train unit critical data delivering path.Can realize sending train critical data to other motor train unit or ground running scheduling command centre respectively according to the priority orders of AP wireless network, GPRS network and these three kinds of communication functions of the two-way short message of BDS triones navigation system by the communication apparatus setting up AP wireless network and BDS triones navigation system to train respectively, give full play to AP wireless network cost performance and efficiency is high and the communication advantage of BDS triones navigation system, significantly enhance promptness and the reliability of motor train unit critical data wireless transmission.Dipper system is applied to EMU navigator fix field by the method first, and solves model selection and the switching problem of BDS triones navigation system and the double mode navigator fix of GPS navigation system.For Equations of The Second Kind to the not high data of requirement of real-time, only just transmitted by the WIFI of AP wireless network at motor train unit vehicle pull-in or to enter when garage is safeguarded, data transmission pressure can be alleviated.

In addition, this method also gives especially a kind ofly only has an enough strong satellite-signal at the Big Dipper, and under GPS has the prerequisite of two enough strong satellite-signals at least, the new location method of signal complementation both realizing further.Thus cannot Double-Star Positioning System be met for triones navigation system, GPS navigation system also cannot meet four stars location in particular cases simultaneously, still realizes complementary compatible positioning and provides new approach.

Accompanying drawing explanation

Fig. 1 is the Double-Star Positioning System principle schematic of old triones navigation system.

Fig. 2 is that the flow process of the motor train unit critical data wireless transmission support method based on double mode navigational system of the present invention is always schemed.

Embodiment

Below in conjunction with accompanying drawing, the present invention is described in further details.

As shown in Figure 2, the motor train unit critical data wireless transmission support method based on double mode navigational system of the present invention comprises the steps:

Step one: for motor train unit train installs teledata radio transmitting device, this device possesses GPS navigation positioning function, BDS Beidou navigation positioning function, GPRS mobile radio network and AP wireless network data passage and debugs respectively, makes it all can work alone;

Step 2: judge the signal strength indicator of current AP wireless network whether >=preset value, if then perform step 3, otherwise, perform step 4;

Step 3: the vehicle communications device enabling AP wireless network connects with the AP wireless network uphole equipment of Along Railway, and by the transfer of AP wireless network, running scheduling command centre transmits whole two class motor train unit critical datas earthward, then performs step 4;

Step 4: judge the signal index of the mobile radio networks such as current GPRS whether >=preset value, if so, then perform step 5, otherwise, perform step 6;

Step 5: adopt the mobile radio networks such as GPRS to carry out the transmission of first kind motor train unit critical data, and re-execute step 2;

Step 6: judge the performance index of the signal of BDS triones navigation system whether >=performance index of the signal of GPS GPS, and car antenna terminal device at least can detect that two intensity are greater than the Big Dipper satellite signal of-133dBm simultaneously, if, then perform step 7, otherwise directly perform step 9;

Step 7: adopt the two-way short message communication function transmission of BDS triones navigation system not comprise all the other whole first kind motor train unit critical datas of train orientation multidate information, then perform step 8;

Step 8: directly adopt BDS triones navigation system to obtain train orientation multidate information, and by the two-way short message communication function of BDS triones navigation system by this train orientation dynamic message transmission to ground running scheduling command centre and other motor train unit, then re-execute step 2;

Step 9: use the multidate information that GPS GPS obtains train orientation instead, it specifically comprises following sub-step:

Step 9.1: judge whether car antenna terminal can detect that at least four signal intensities are greater than the gps satellite signal of-130dBm, if so, then perform step 10 simultaneously, otherwise, perform step 9.2;

Step 9.2: judge whether car antenna terminal can detect that at least two signal intensities are greater than the gps satellite signal of-130dBm simultaneously, and can also detect that at least one signal intensity is greater than the Big Dipper satellite signal of-133dBm simultaneously, if, then perform step 11, otherwise, perform step 9.3;

Step 9.3: abandon this satnav and communication, and after three minutes, re-execute step 2 in time delay;

Step 10: only adopt the train orientation multidate information of GPS GPS to current motor train unit self to carry out independently resolving and storing, then re-execute step 2;

Step 11: the train orientation multidate information adopting big-dipper satellite and gps satellite hybrid navigation location technology to obtain current motor train unit self carries out independently resolving and storing, and then re-executes step 2;

As described in step 6, the performance index of the signal of navigational system are the weighted mean value of detection probability, false alarm rate, mean acquisition time three indexs.

The concrete scheme that employing big-dipper satellite described in step 11 and gps satellite hybrid navigation are located comprises the steps:

Step 11.1: judge whether simultaneously can detect that three signal intensities are greater than the gps satellite signal of-130dBm by car antenna terminal described in step 9.2, and can also detect that at least one signal intensity is greater than the Big Dipper satellite signal of-133dBm simultaneously, if then perform step 11.2, otherwise, perform step 11.7;

Step 11.2: by Big Dipper positioning equation group with become GPS positioning equation group and combine, form the first complementation and resolve system of equations, to resolve the three-dimensional coordinate (X, Y, Z) of current motor train unit self:

$\left\{\begin{array}{c}2(R_{S0}+R_0)={\mathrm{c\Δt}}_{B1}\\ R_0=\sqrt{{(X-X_0)}^2+{(Y-Y_0)}^2+{(Z-Z_0)}^2}\\ R_i={\mathrm{c\Δt}}_i\\ R_i=\sqrt{{(X-X_i)}^2+{(Y-Y_i)}^2+{(Z-Z_i)}^2}\end{array}\right.---\left(7\right)$

In formula (7), R _s0for ground running scheduling command centre is to the distance of big-dipper satellite S0, S0 is known quantity; Constant c represents satellite signal transit speed, is also known quantity; Coordinate figure (X ₀, Y ₀, Z ₀) be big-dipper satellite 3 d space coordinate, and coordinate figure (X _i, Y _i, Z _i) wherein i=1,2,3 represent the 3 d space coordinate of three gps satellites respectively; The spatial value of above-mentioned four satellites is all the known quantities that can obtain at any time;

In variable to be solved, △ t _b1represent the first retardation t _b1to expend time in t in satellite S0 place's transfer with signal _s0mistiming; △ t _irepresent that terminal device receives the time of gps satellite signal and the difference of satellite transmitted signal time; (X, Y, Z) is train D coordinates value to be solved;

Step 11.3: Cramer's rule (Cramer's Rule) be in linear algebra one about the known theorem solving system of linear equations, directly formula (7) is launched to be transformed to by application carat method of writing from memory:

$\left\{\begin{array}{cc}{(X-X_0)}^2+{(Y-Y_0)}^2+{(Z-Z_0)}^2={(\frac{1}{2}{\mathrm{c\Δt}}_{B1}-R_{S0})}^2=R_0^2& \left(a\right)\\ {(X-X_1)}^2+{(Y-Y_1)}^2+{(Z-Z_1)}^2={\left({\mathrm{c\Δt}}_1\right)}^2=R_1^2& \left(b\right)\\ {(X-X_2)}^2+{(Y-Y_2)}^2+{(Z-Z_2)}^2={\left({\mathrm{c\Δt}}_3\right)}^2=R_2^2& \left(c\right)\\ {(X-X_3)}^2+{(Y-Y_3)}^2+{(Z-Z_3)}^2={\left({\mathrm{c\Δt}}_3\right)}^2=R_3^2& \left(d\right)\end{array}\right.---\left(8\right)$

Step 11.4: arrange formula (8), does difference with formula (b), formula (c) and formula (d) respectively by formula (a), then can obtain three new system of equations:

$\left\{\begin{array}{c}({2X}_1-{2X}_0)X+({2Y}_1-{2Y}_0)Y+({2Z}_1-{2Z}_0)Z=R_1^2-R_0^2+X_1^2+Y_1^2+Z_1^2-X_0^2-Y_0^2-Z_0^2\\ ({2X}_2-{2X}_0)X+({2Y}_2-{2Y}_0)Y+({2Z}_2-{2Z}_0)Z=R_2^2-R_0^2+X_2^2+Y_2^2+Z_2^2-X_0^2-Y_0^2-Z_0^2\\ ({2X}_3-{2X}_0)X+({2Y}_3-{2Y}_0)Y+({2Z}_3-{2Z}_0)Z=R_3^2-R_0^2+X_3^2+Y_3^2+Z_3^2-X_0^2-Y_0^2-Z_0^2\end{array}\right.$

Step 11.5: above formula is written as Cramer's rule form:

$\left\{\begin{array}{c}{a}_{11}X+a_{12}Y+a_{13}Z=b_1\\ a_{21}X+a_{22}Y+a_{33}Z=b_2\\ a_{31}X+a_{32}Y+a_{33}Z=b_3\end{array}\right.---\left(9\right)$

In formula (9), a _mn(m, n are natural number) is matrix coefficient;

Step 11.6: application Cramer's rule, then the train D coordinates value (X, Y, Z) solved:

$X=\frac{\left|\begin{array}{ccc}{b}_1& a_{12}& a_{13}\\ b_2& a_{22}& a_{23}\\ b_3& a_{32}& a_{33}\end{array}\right|}{\left|\begin{array}{ccc}{a}_{11}& a_{12}& a_{13}\\ a_{21}& a_{22}& a_{23}\\ a_{31}& a_{32}& a_{33}\end{array}\right|},Y=\frac{\left|\begin{array}{ccc}{a}_{11}& b_1& a_{13}\\ a_{21}& b_2& a_{23}\\ a_{31}& b_3& a_{33}\end{array}\right|}{\left|\begin{array}{ccc}{a}_{11}& a_{12}& a_{13}\\ a_{21}& a_{22}& a_{23}\\ a_{31}& a_{32}& a_{33}\end{array}\right|},Z=\frac{\left|\begin{array}{ccc}{a}_{11}& a_{12}& b_1\\ a_{21}& a_{22}& b_2\\ a_{31}& a_{32}& b_3\end{array}\right|}{\left|\begin{array}{ccc}{a}_{11}& a_{12}& a_{13}\\ a_{21}& a_{22}& a_{23}\\ a_{31}& a_{32}& a_{33}\end{array}\right|}$

Try to achieve the three-dimensional coordinate that coordinate figure (X, Y, Z) is current motor train unit car antenna terminal device self;

Step 11.7: judge whether only simultaneously can detect that two signal intensities are greater than the gps satellite signal of-130dBm by the car antenna terminal described in step 9.2, and can also detect that at least one signal intensity is greater than the Big Dipper satellite signal of-133dBm simultaneously, if, then perform step 11.8, otherwise, abandon this satnav and communication, and after three minutes, re-execute step 2 in time delay;

Step 11.8: by Big Dipper positioning equation group with become GPS positioning equation group and combine, form the second complementation and resolve system of equations, to resolve two-dimensional coordinate (X, Y) value of current motor train unit self:

$\left\{\begin{array}{c}2(R_{S0}+R_0)={\mathrm{c\Δt}}_{B1}\\ R_0=\sqrt{{(X-X_0)}^2+{(Y-Y_0)}^2}\\ R_i={\mathrm{c\Δt}}_i\\ R_i=\sqrt{{(X-X_i)}^2+{(Y-Y_i)}^2}\end{array}\right.---\left(10\right)$

Each parameter implication in formula (10) is all identical with the solution procedure that system of equations is resolved in the first complementation with method for solving, but only has two, gps satellite coordinate figure (X in this system of equations due to gps satellite signal _i, Y _i, Z _i) in i can only be 1 or 2, and coordinate figure i=1,2 represent the 3 d space coordinate of two gps satellites respectively, therefore preceding method only can calculate the numerical value of space two-dimensional coordinate X, Y, and its solution process is as follows:

Step 11.9: directly formula (10) is launched to be transformed to by application carat method of writing from memory:

$\left\{\begin{array}{cc}{(X-X_0)}^2+{(Y-Y_0)}^2={(\frac{1}{2}{\mathrm{c\Δt}}_{B1}-R_{S0})}^2=R_0^2& \left(a\right)\\ {(X-X_1)}^2+{(Y-Y_1)}^2={\left({\mathrm{c\Δt}}_1\right)}^2=R_1^2& \left(b\right)\\ {(X-X_2)}^2+{(Y-Y_2)}^2={\left({\mathrm{c\Δt}}_3\right)}^2=R_2^2& \left(c\right)\end{array}\right.---\left(11\right)$

Step 11.10: arrange formula (11), does difference with formula (b), formula (c) respectively by formula (a), then can obtain three new system of equations:

$\left\{\begin{array}{c}({2X}_1-{2X}_0)X+({2Y}_1-{2Y}_0)Y=R_1^2-R_0^2+X_1^2+Y_1^2-X_0^2-Y_0^2\\ ({2X}_2-{2X}_0)X+({2Y}_2-{2Y}_0)Y=R_2^2-R_0^2+X_2^2+Y_2^2-X_0^2-Y_0^2\end{array}\right.$

Step 11.11: above formula is written as Cramer's rule form:

$\left\{\begin{array}{c}{a}_{11}X+a_{12}Y=b_1\\ a_{21}X+a_{22}Y=b_2\end{array}\right.---\left(12\right)$

In formula (12), a _mn(m, n are natural number) is matrix coefficient;

Step 11.12: application Cramer's rule, then the train D coordinates value (X, Y) solved:

$X=\frac{\left|\begin{array}{cc}{b}_1& a_{12}\\ b_2& a_{22}\end{array}\right|}{\left|\begin{array}{cc}{a}_{11}& a_{12}\\ a_{21}& a_{22}\end{array}\right|},Y=\frac{\left|\begin{array}{cc}{a}_{11}& b_1\\ a_{12}& b_2\end{array}\right|}{\left|\begin{array}{cc}{a}_{11}& a_{12}\\ a_{21}& a_{22}\end{array}\right|},$

Try to achieve the two-dimensional coordinate that coordinate figure (X, Y) is current motor train unit car antenna terminal device self;

Step 11.13: above-mentioned system of equations can only calculate the two-dimensional coordinate of vehicle-mounted terminal equipment, the space height value Z of train D coordinates value cannot provide, but, train two-dimensional coordinate value (X, Y) the theoretical height value Z that this coordinate figure of digitalized electron map inquiry is current along the railway tried to achieve according to step 11.12 by the ground running scheduling command centre of big-dipper satellite, thus also can calculate 3 d space coordinate.

The invention has the beneficial effects as follows: the method overcome the single and undue problem relying on GPRS mobile communications network of existing train of high-speed motor train unit critical data delivering path.Can realize sending train critical data to other motor train unit or ground running scheduling command centre respectively according to the priority orders of AP wireless network, GPRS network and these three kinds of communication functions of the two-way short message of BDS triones navigation system by the communication apparatus setting up AP wireless network and BDS triones navigation system to train respectively, give full play to AP wireless network cost performance and efficiency is high and the communication advantage of BDS triones navigation system, significantly enhance promptness and the reliability of motor train unit critical data wireless transmission.Dipper system is applied to EMU navigator fix field by the method first, and solves model selection and the switching problem of BDS triones navigation system and the double mode navigator fix of GPS navigation system.

For Equations of The Second Kind to the not high data of requirement of real-time, only just transmitted by the WIFI of AP wireless network at motor train unit vehicle pull-in or to enter when garage is safeguarded, data transmission pressure can be alleviated.

In addition, this method also gives especially a kind ofly only has an enough strong satellite-signal at the Big Dipper, and under GPS has the prerequisite of two enough strong satellite-signals at least, the new location method of signal complementation both realizing further.Thus cannot Double-Star Positioning System be met for triones navigation system, GPS navigation system also cannot meet four stars location in particular cases simultaneously, still realizes complementary compatible positioning and provides new approach.

Claims (2)

1., based on the motor train unit critical data wireless transmission support method of double mode navigational system, the method comprises the steps:

Step one: for motor train unit train installs teledata radio transmitting device, this device possesses GPS navigation positioning function, BDS Beidou navigation positioning function, GPRS mobile radio network and AP wireless network data passage and debugs respectively, makes it all can work alone;

Step 2: judge the signal strength indicator of current AP wireless network whether >=preset value, if then perform step 3, otherwise, perform step 4;

Step 3: the vehicle communications device enabling AP wireless network connects with the AP wireless network uphole equipment of Along Railway, and by the transfer of AP wireless network, running scheduling command centre transmits whole two class motor-car critical datas earthward, then performs step 4;

Step 4: judge the signal index of the mobile radio networks such as current GPRS whether >=preset value, if so, then perform step 5, otherwise, perform step 6;

Step 5: adopt the mobile radio networks such as GPRS to carry out the transmission of first kind motor-car critical data, and re-execute step 2;

Step 6: judge the performance index of the signal of BDS triones navigation system whether >=performance index of the signal of GPS GPS, and car antenna terminal device at least can detect that two intensity are greater than the Big Dipper satellite signal of-133dBm simultaneously, if, then perform step 7, otherwise directly perform step 9;

Step 7: adopt the two-way short message communication function transmission of BDS triones navigation system not comprise all the other whole first kind motor-car critical datas of train orientation multidate information, then perform step 8;

Step 8: directly adopt BDS triones navigation system to obtain train orientation multidate information, and by the two-way short message communication function of BDS triones navigation system by this train orientation dynamic message transmission to ground running scheduling command centre and other motor-car, then re-execute step 2;

Step 9: use the multidate information that GPS GPS obtains train orientation instead, it specifically comprises following sub-step:

Step 9.1: judge whether car antenna terminal can detect that at least four signal intensities are greater than the gps satellite signal of-130dBm, if so, then perform step 10 simultaneously, otherwise, perform step 9.2;

Step 9.2: judge whether car antenna terminal can detect that at least two signal intensities are greater than the gps satellite signal of-130dBm simultaneously, and can also detect that at least one signal intensity is greater than the Big Dipper satellite signal of-133dBm simultaneously, if, then perform step 11, otherwise, perform step 9.3;

Step 9.3: abandon this satnav and communication, and after three minutes, re-execute step 2 in time delay;

Step 10: only adopt the train orientation multidate information of GPS GPS to current motor-car self to carry out independently resolving and storing, then re-execute step 2;

Step 11: the train orientation multidate information adopting big-dipper satellite and gps satellite hybrid navigation location technology to obtain current motor-car self carries out independently resolving and storing, and then re-executes step 2;

As described in step 6, the performance index of the signal of navigational system are the weighted mean value of detection probability, false alarm rate, mean acquisition time three indexs.

2., as claimed in claim 1 based on the motor train unit critical data wireless transmission support method of double mode navigational system, it is characterized in that, the concrete scheme that the employing big-dipper satellite described in step 11 and gps satellite hybrid navigation are located comprises the steps:

Step 11.1: judge whether simultaneously can detect that three signal intensities are greater than the gps satellite signal of-130dBm by car antenna terminal described in step 9.2, and can also detect that at least one signal intensity is greater than the Big Dipper satellite signal of-133dBm simultaneously, if then perform step 11.2, otherwise, perform step 11.7;

Step 11.2: by Big Dipper positioning equation group with become GPS positioning equation group and combine, form the first complementation and resolve system of equations, to resolve the three-dimensional coordinate (X, Y, Z) of current motor-car self:

$\left\{\begin{array}{c}2(R_{S0}+R_0)=c{\mathrm{\Δt}}_{B1}\\ R_0=\sqrt{{(X-X_0)}^2+{(Y-Y_0)}^2+{(Z-Z_0)}^2}\\ R_i=c{\mathrm{\Δt}}_i\\ R_i=\sqrt{{(X-X_i)}^2+{(Y-Y_i)}^2+{(Z-Z_i)}^2}\end{array}\right.---\left(7\right)$

In formula (7), R _s0for ground running scheduling command centre is to the distance of big-dipper satellite S0, S0 is known quantity; Constant c represents satellite signal transit speed, is also known quantity; Coordinate figure (X ₀, Y ₀, Z ₀) be big-dipper satellite 3 d space coordinate, and coordinate figure (X _i, Y _i, Z _i) wherein i=1,2,3 represent the 3 d space coordinate of three gps satellites respectively; The spatial value of above-mentioned four satellites is all the known quantities that can obtain at any time;

In variable to be solved, △ t _b1represent the first retardation t _b1to expend time in t in satellite S0 place's transfer with signal _s0mistiming; △ t _irepresent that terminal device receives the time of gps satellite signal and the difference of satellite transmitted signal time; (X, Y, Z) is train D coordinates value to be solved;

Step 11.3: directly formula (7) is launched to be transformed to by application carat method of writing from memory:

$\left\{\begin{array}{cc}{(X-X_0)}^2+{(Y-Y_0)}^2+{(Z-Z_0)}^2={(\frac{1}{2}c{\mathrm{\Δt}}_{B1}-R_{S0})}^2=R_0^2& \left(a\right)\\ {(X-X_1)}^2+{(Y-Y_1)}^2+{(Z-Z_1)}^2={\left({\mathrm{c\Δt}}_1\right)}^2=R_1^2& \left(b\right)\\ {(X-X_2)}^2+{(Y-Y_2)}^2+{(Z-Z_2)}^2={\left(c{\mathrm{\Δt}}_2\right)}^2=R_2^2& \left(c\right)\\ {(X-X_3)}^2+{(Y-Y_3)}^2+{(Z-Z_3)}^2={\left(c{\mathrm{\Δt}}_3\right)}^2=R_3^2& \left(d\right)\end{array}\right.---\left(8\right)$

Step 11.4: arrange formula (8), does difference with formula (b), formula (c) and formula (d) respectively by formula (a), then can obtain three new system of equations:

$\left\{\begin{array}{c}({2X}_1-{2X}_0)X+({2Y}_1-{2Y}_0)Y+({2Z}_1-{2Z}_0)Z=R_1^2-R_0^2+X_1^2+Y_1^2+Z_1^2-X_0^2-Y_0^2-Z_0^2\\ ({2X}_2-{2X}_0)X+({2Y}_2-{2Y}_0)Y+({2Z}_2-{2Z}_0)Z=R_2^2-R_0^2+X_2^2+Y_2^2+Z_2^2-X_0^2-Y_0^2-Z_0^2\\ ({2X}_3-{2X}_0)X+({2Y}_3-{2Y}_0)Y+({2Z}_3-{2Z}_0)Z=R_3^2-R_0^2+X_3^2+Y_3^2+Z_3^2-X_0^2-Y_0^2-Z_0^2\end{array}\right.$

Step 11.5: above formula is written as Cramer's rule form:

$\left\{\begin{array}{c}{a}_{11}X+a_{12}Y+a_{13}Z=b_1\\ a_{21}X+a_{22}Y+a_{23}Z=b_2\\ a_{31}X+a_{32}Y+a_{33}Z=b_3\end{array}\right.---\left(9\right)$

In formula (9), a _mn(m, n are natural number) is matrix coefficient;

Step 11.6: application Cramer's rule, then the train D coordinates value (X, Y, Z) solved:

$X=\frac{\left|\begin{array}{ccc}{b}_1& a_{12}& a_{13}\\ b_2& a_{22}& a_{23}\\ b_3& a_{32}& a_{33}\end{array}\right|}{\left|\begin{array}{ccc}{a}_{11}& a_{12}& a_{13}\\ a_{21}& a_{22}& a_{23}\\ a_{31}& a_{32}& a_{33}\end{array}\right|},Y=\frac{\left|\begin{array}{ccc}{a}_{11}& b_1& a_{13}\\ a_{21}& b_2& a_{23}\\ a_{31}& b_3& a_{33}\end{array}\right|}{\left|\begin{array}{ccc}{a}_{11}& a_{12}& a_{13}\\ a_{21}& a_{22}& a_{23}\\ a_{31}& a_{32}& a_{33}\end{array}\right|},Z=\frac{\left|\begin{array}{ccc}{a}_{11}& a_{12}& b_1\\ a_{21}& a_{22}& b_2\\ a_{31}& a_{32}& b_3\end{array}\right|}{\left|\begin{array}{ccc}{a}_{11}& a_{12}& a_{13}\\ a_{21}& a_{22}& a_{23}\\ a_{31}& a_{32}& a_{33}\end{array}\right|}$

Try to achieve the three-dimensional coordinate that coordinate figure (X, Y, Z) is current motor-car car antenna terminal device self;

Step 11.7: judge whether only simultaneously can detect that two signal intensities are greater than the gps satellite signal of-130dBm by the car antenna terminal described in step 9.2, and can also detect that at least one signal intensity is greater than the Big Dipper satellite signal of-133dBm simultaneously, if, then perform step 11.8, otherwise, abandon this satnav and communication, and after three minutes, re-execute step 2 in time delay;

Step 11.8: by Big Dipper positioning equation group with become GPS positioning equation group and combine, form the second complementation and resolve system of equations, to resolve two-dimensional coordinate (X, Y) value of current motor-car self:

$\left\{\begin{array}{c}2(R_{S0}+R_0)=c{\mathrm{\Δt}}_{B1}\\ R_0=\sqrt{{(X-X_0)}^2+{(Y-Y_0)}^2}\\ R_i=c{\mathrm{\Δt}}_i\\ R_i=\sqrt{{(X-X_i)}^2+{(Y-Y_i)}^2}\end{array}\right.---\left(10\right)$

Each parameter implication in formula (10) is all identical with the solution procedure that system of equations is resolved in the first complementation with method for solving, but only has two, gps satellite coordinate figure (X in this system of equations due to gps satellite signal _i, Y _i, Z _i) in i can only be 1 or 2, and coordinate figure i=1,2 represent the 3 d space coordinate of two gps satellites respectively, its solution process is as follows:

Step 11.9: directly formula (10) is launched to be transformed to by application carat method of writing from memory:

$\left\{\begin{array}{cc}{(X-X_0)}^2+{(Y-Y_0)}^2={(\frac{1}{2}{\mathrm{c\Δt}}_{B1}-R_{S0})}^2=R_0^2& \left(a\right)\\ {(X-X_1)}^2+{(Y-Y_1)}^2={\left({\mathrm{c\Δt}}_1\right)}^2=R_1^2& \left(b\right)\\ {(X-X_2)}^2+{(Y-Y_2)}^2={\left({\mathrm{c\Δt}}_2\right)}^2=R_2^2& \left(c\right)\end{array}\right.---\left(11\right)$

Step 11.10: arrange formula (11), does difference with formula (b), formula (c) respectively by formula (a), then can obtain three new system of equations:

$\left\{\begin{array}{c}({2X}_1-{2X}_0)X+({2Y}_1-{2Y}_0)Y=R_1^2-R_0^2+X_1^2+Y_1^2-X_0^2-Y_0^2\\ ({2X}_2-{2X}_0)X+({2Y}_2-{2Y}_0)Y=R_2^2-R_0^2+X_2^2+Y_2^2-X_0^2-Y_0^2\end{array}\right.$

Step 11.11: above formula is written as Cramer's rule form:

$\left\{\begin{array}{c}{a}_{11}X+a_{12}Y=b_1\\ a_{21}X+a_{22}Y=b_2\end{array}\right.---\left(12\right)$

In formula (12), a _mn(m, n are natural number) is matrix coefficient;

Step 11.12: application Cramer's rule, then the train D coordinates value (X, Y) solved:

$X=\frac{\left|\begin{array}{cc}{b}_1& a_{12}\\ b_2& a_{22}\end{array}\right.}{\left|\begin{array}{cc}{a}_{11}& a_{12}\\ a_{21}& a_{22}\end{array}\right|},Y=\frac{\left|\begin{array}{cc}{a}_{11}& b_1\\ a_{12}& b_2\end{array}\right|}{\left|\begin{array}{cc}{a}_{11}& a_{12}\\ a_{21}& a_{22}\end{array}\right|}$

Try to achieve the two-dimensional coordinate that coordinate figure (X, Y) is current motor-car car antenna terminal device self;

Step 11.13: train two-dimensional coordinate value (X, Y) the theoretical height value Z that this coordinate figure of digitalized electron map inquiry is current along the railway that the ground running scheduling command centre of big-dipper satellite tries to achieve according to step 11.12, thus also can calculate 3 d space coordinate.