阅读说明：本技术 一种基于5g通信的车辆间协同导航定位方法 (5G communication-based collaborative navigation positioning method between vehicles ) 是由 施闯 辜声峰 宋伟 唐卫明 于 2019-10-12 设计创作，主要内容包括：本发明公开了基于5G通信的车辆间协同导航定位方法,包括：获取各5G基站对之间共视卫星双差模糊度第一固定值；估计各5G基站的单天静态坐标以及所述5G基站与其各跟踪卫星的非差整周模糊度第一固定值；获取对应的5G基站对之间共视卫星双差模糊度第二固定值；获取所述5G基站与其各跟踪卫星的非差整周模糊度第二固定值,进而获得所述5G基站的不含模糊度参数的测相伪距观测值；车辆获取高精度位置信息及周边车辆位置信息；车辆间建立D2D通讯,实现所述中心车辆与其周边车辆协同导航定位。本发明以GNSS高精度定位为基础,结合5G通信D2D技术,实现了车辆间的高精度协同定位。(The invention discloses a 5G communication-based collaborative navigation positioning method between vehicles, which comprises the following steps: acquiring a first fixed value of double-difference ambiguity of a common-view satellite between each 5G base station pair; estimating a single-day static coordinate of each 5G base station and a first fixed value of non-difference integer ambiguity of the 5G base station and each tracking satellite thereof; acquiring a second fixed value of double-difference ambiguity of the common-view satellite between the corresponding 5G base station pairs; acquiring a second fixed value of non-difference integer ambiguity between the 5G base station and each tracking satellite thereof, and further acquiring a phase measurement pseudorange observation value of the 5G base station without ambiguity parameters; the vehicle acquires high-precision position information and peripheral vehicle position information; D2D communication is established among the vehicles, and the center vehicle and the surrounding vehicles are cooperatively navigated and positioned. The invention realizes the high-precision cooperative positioning between vehicles by combining the 5G communication D2D technology on the basis of GNSS high-precision positioning.)

1. A collaborative navigation positioning method between vehicles based on 5G communication is characterized in that a 5G base station carrying a GNSS receiver is utilized to realize collaborative navigation positioning between vehicles carrying the GNSS receiver and provided with a 5G communication module, and the method comprises the following steps:

s1: according to a Dirony triangulation network division principle, a 5G base station network topological structure is established and stored in each 5G base station;

s2: in a static mode, acquiring a first fixed value of double-difference ambiguity of a common-view satellite between base station pairs, wherein each base station pair consists of a pair of 5G base stations at any two ends of a triangular network connecting line of a 5G base station network topological structure;

s3: estimating and acquiring a single-day static coordinate of each 5G base station and a first fixed value of non-differential integer ambiguity of the 5G base station and each tracking satellite thereof by using a non-differential precise point positioning technology and a non-differential ambiguity fixing technology PPP-AR;

s4: acquiring a second fixed value of double-difference ambiguity of a common-view satellite between the base station pairs based on the first fixed value of non-difference integer ambiguity of the 5G base stations at the two ends of the base station pairs and the tracking satellites;

s5: judging that the first fixed value of the double-difference ambiguity of the common-view satellite between the base station pairs acquired in the step S2 is equal to the second fixed value of the double-difference ambiguity of the common-view satellite between the corresponding base station pairs acquired in the step S4, and if the first fixed value of the double-difference ambiguity of the common-view satellite between the base station pairs acquired in the step S6 is equal to the second fixed value of the double-difference ambiguity of the common; otherwise, the second fixed value mark of the non-difference integer ambiguity of the 5G base station and each tracking satellite is cancelled, the second fixed value mark is used as an unknown parameter again, the step S3 is returned to re-estimate the first fixed value of the non-difference integer ambiguity of the 5G base station and each tracking satellite until the equal judgment is passed;

s6: marking a first fixed value of the non-differential integer ambiguity of each 5G base station and each tracking satellite thereof as a second fixed value of the non-differential integer ambiguity of the 5G base station and each tracking satellite thereof, and taking the second fixed value as a known value to be brought into a phase observation value of the 5G base station, thereby obtaining a phase measurement pseudorange observation value of the 5G base station, which does not contain an ambiguity parameter;

s7: each vehicle forms a double-difference observation value based on observation data of a GNSS receiver of each vehicle and a phase measurement pseudo-range observation value of a 5G base station accessed to the GNSS receiver, then the 5G base station is used as a reference station, a satellite with the largest elevation angle in common visible satellites of the vehicle and the 5G base station is used as a reference satellite, baseline resolution is carried out according to a dynamic mode, and position information of the vehicle is obtained and transmitted back to the 5G base station;

s8: each 5G base station collects the position information of vehicles accessing the 5G base station and all vehicles accessing the other end 5G base station of the triangular network connection line containing the 5G base station, acquires the position information of surrounding vehicles taking each vehicle as a center vehicle and within a certain radius range of the vehicle, and reports the position information to the center vehicle and the surrounding vehicles;

s9: after each center vehicle acquires the position information of the surrounding vehicles, the communication relation between the center vehicle and the surrounding vehicles is established directly by the D2D technology in 5G communication;

s10: and each central vehicle is contacted with the nearest 5G base station at any moment, data updating and transmission are carried out, the position information of the surrounding vehicles is updated in real time, and the cooperative navigation positioning between the central vehicle and the surrounding vehicles is realized.

2. The method according to claim 1, wherein the step S2 includes the following specific steps:

according to the 5G base station network topology structure established in the step S1, each 5G base station collects the observation data of the GNSS receiver thereof, and collects the observation data of the GNSS receiver of the other end 5G base station of the triangulation network connection including the 5G base station, the 5G base station is selected as a reference station, the satellite with the largest elevation angle in the common-view satellites of the 5G base station and the other end 5G base station of the triangulation network connection including the 5G base station is selected as a reference satellite to form a double-difference observation value, all base station pairs are subjected to baseline solution according to a static mode, a first fixed value of the double-difference ambiguity of the common-view satellites between the base station pairs is obtained,

wherein, the double-difference observation equation is as follows:

in the formula (I), the compound is shown in the specification,

3. The method according to claim 1, wherein the step S3 includes the following specific steps:

for each 5G base station, acquiring observation data of a GNSS receiver of the base station, combining correction numbers of a precise satellite orbit, a clock error and a phase deviation which are broadcast by a satellite-based augmentation system or a wide-area real-time precise positioning system, adopting a non-difference GNSS precise single-point positioning technology and a non-difference ambiguity fixing technology PPP-AR, estimating a single-day static coordinate of the 5G base station and a first fixed value of the non-difference integer ambiguity of the 5G base station and each tracking satellite thereof according to a single-day static mode,

wherein, the non-differential GNSS precise single-point positioning observation model is

In the formula (I), the compound is shown in the specification,

4. The method according to claim 1, wherein step S4 is implemented as follows:

for each 5G base station, acquiring a first fixed value of the non-differential ambiguity of the base station and each tracking satellite, collecting a first fixed value of the non-differential ambiguity of the other end 5G base station of the triangulation network connecting line containing the 5G base station and each tracking satellite, and acquiring a second fixed value of the double-differential ambiguity of the common-view satellites between the base stations corresponding to the 5G base station by taking the 5G base station as a reference station and the satellite with the largest elevation angle in the common-view satellites of the other end 5G base station of the triangulation network connecting line of the 5G base station and the reference satellite.

5. The method of claim 1, wherein in step S5, when the tracking satellite of the 5G base station has a week skip, the non-integer ambiguity second fixed value flag corresponding to the satellite is cancelled, and the estimation is returned to step S3 for re-estimation until the equality determination is passed.

6. The method of claim 1, wherein in step S1, the established topology of the dironi triangle network of the 5G base station is stored in each 5G base station, and the topology of the dironi triangle network of the 5G base station is updated when a new 5G base station is installed or an existing 5G base station exits from service, and each 5G base station is notified to update.

Technical Field

The invention belongs to the field of GNSS-based navigation positioning, and particularly relates to a method for cooperative positioning between vehicles based on high-precision position information and combined with a 5G communication D2D technology.

Background

Under the promotion of artificial intelligence and big data, the cooperation between the traditional vehicle enterprises and the scientific and technological companies is more and more compact, the mass production of the vehicle networking and the automatic driving vehicle is increasingly popularized to become a new trend in the field of travel, and the layouts of the vehicle networking, the automatic driving and the like of the Internet and the scientific and technological huge have become effective initially. The development of the domestic internet of vehicles and the automatic driving industry is further promoted by an intelligent internet automobile technology route map issued by the Ministry of industry and belief in 2017. China manufacturing 2025 also gives a development target of the intelligent internet automobile, so that the trend of the stage improvement of the automatic driving technology in China is clarified, the development of the intelligent internet automobile industry in China is accelerated, the difference between the automatic driving technology and the internet technology in China and foreign countries is closed, and the curve overtaking is realized as soon as possible.

On the other hand, with the commercialization of the 5G technology, a new generation of display technology will be brought about, and true world-wide interconnection is expected to be achieved. In particular by combining one of the 5G key technologies: the combination of Device-to-Device (D2D) and the Internet of vehicles is expected to greatly improve the data transmission efficiency and reliability, reduce the data transmission delay and further promote the development of the Internet of vehicles and automatic driving.

Automobile safety is a major topic of sustainable development of the internet of vehicles and automatic driving, and realizing high-precision cooperative positioning between vehicles is a key for realizing active obstacle avoidance between vehicles and improving automobile driving safety, and breakthrough is urgently needed.

Disclosure of Invention

Therefore, the invention provides a high-precision co-positioning method between vehicles based on GNSS high-precision positioning and combined with 5G communication D2D technology.

The invention provides a 5G communication-based collaborative navigation positioning method among vehicles, which utilizes a 5G base station carrying a GNSS receiver to realize the collaborative navigation positioning among vehicles carrying the GNSS receiver and provided with a 5G communication module, and comprises the following steps:

s1: according to a Dirony triangulation network division principle, a 5G base station network topological structure is established and stored in each 5G base station;

s2: in a static mode, acquiring a first fixed value of double-difference ambiguity of a common-view satellite between base station pairs, wherein each base station pair consists of a pair of 5G base stations at any two ends of a triangular network connecting line of a 5G base station network topological structure;

s3: estimating and acquiring a single-day static coordinate of each 5G base station and a first fixed value of non-differential integer ambiguity of the 5G base station and each tracking satellite thereof by using a non-differential precise point positioning technology and a non-differential ambiguity fixing technology PPP-AR;

s4: acquiring a second fixed value of double-difference ambiguity of a common-view satellite between the base station pairs based on the first fixed value of non-difference integer ambiguity of the 5G base stations at the two ends of the base station pairs and the tracking satellites;

s5: judging that the first fixed value of the double-difference ambiguity of the common-view satellite between the base station pairs acquired in the step S2 is equal to the second fixed value of the double-difference ambiguity of the common-view satellite between the corresponding base station pairs acquired in the step S4, and if the first fixed value of the double-difference ambiguity of the common-view satellite between the base station pairs acquired in the step S6 is equal to the second fixed value of the double-difference ambiguity of the common; otherwise, the second fixed value mark of the non-difference integer ambiguity of the 5G base station and each tracking satellite is cancelled, the second fixed value mark is used as an unknown parameter again, the step S3 is returned to re-estimate the first fixed value of the non-difference integer ambiguity of the 5G base station and each tracking satellite until the equal judgment is passed;

s6: marking a first fixed value of the non-differential integer ambiguity of each 5G base station and each tracking satellite thereof as a second fixed value of the non-differential integer ambiguity of the 5G base station and each tracking satellite thereof, and taking the second fixed value as a known value to be brought into a phase observation value of the 5G base station, thereby obtaining a phase measurement pseudorange observation value of the 5G base station, which does not contain an ambiguity parameter;

s7: each vehicle forms a double-difference observation value based on observation data of a GNSS receiver of each vehicle and a phase measurement pseudo-range observation value of a 5G base station accessed to the GNSS receiver, then the 5G base station is used as a reference station, a satellite with the largest elevation angle in common visible satellites of the vehicle and the 5G base station is used as a reference satellite, baseline resolution is carried out according to a dynamic mode, and position information of the vehicle is obtained and transmitted back to the 5G base station;

s8: each 5G base station collects the position information of vehicles accessing the 5G base station and all vehicles accessing the other end 5G base station of the triangular network connection line containing the 5G base station, acquires the position information of surrounding vehicles taking each vehicle as a center vehicle and within a certain radius range of the vehicle, and reports the position information to the center vehicle and the surrounding vehicles;

s9: after each center vehicle acquires the position information of the surrounding vehicles, the communication relation between the center vehicle and the surrounding vehicles is established directly by the D2D technology in 5G communication;

s10: and each central vehicle is contacted with the nearest 5G base station at any moment, data updating and transmission are carried out, the position information of the surrounding vehicles is updated in real time, and the cooperative navigation positioning between the central vehicle and the surrounding vehicles is realized.

Further, the step S2 includes:

according to the 5G base station network topology structure established in the step S1, each 5G base station collects the observation data of the GNSS receiver thereof, and collects the observation data of the GNSS receiver of the other end 5G base station of the triangulation network connection including the 5G base station, the 5G base station is selected as a reference station, the satellite with the largest elevation angle in the common-view satellites of the 5G base station and the other end 5G base station of the triangulation network connection including the 5G base station is selected as a reference satellite to form a double-difference observation value, all base station pairs are subjected to baseline solution according to a static mode, a first fixed value of the double-difference ambiguity of the common-view satellites between the base station pairs is obtained,

wherein, the double-difference observation equation is as follows:

in the formula (I), the compound is shown in the specification,

the carrier phase double-difference observation value obtained by calculating the difference between the 5G base station and the common-view satellite is shown;

the double differences of the satellite distance between the 5G base station and the common-view satellite are calculated;

the ambiguity of the whole cycle is calculated between the 5G base station and the common-view satellite;

respectively indicating that the errors of the ionosphere and the troposphere are solved into double differences between the 5G base station and the common-view satellite; f and c represent the signal frequency and the speed of light, respectively.

Further, the step S3 includes:

for each 5G base station, acquiring observation data of a GNSS receiver of the base station, combining correction numbers of a precise satellite orbit, a clock error and a phase deviation which are broadcast by a satellite-based augmentation system or a wide-area real-time precise positioning system, adopting a non-difference GNSS precise single-point positioning technology and a non-difference ambiguity fixing technology PPP-AR, estimating a single-day static coordinate of the 5G base station and a first fixed value of the non-difference integer ambiguity of the 5G base station and each tracking satellite thereof according to a single-day static mode,

wherein, the non-differential GNSS precise single-point positioning observation model is

In the formula (I), the compound is shown in the specification,O-C values representing pseudo-range, phase, Doppler observation vector, respectively, including utilization modesType corrected error, subscript f denotes the corresponding frequency;

the coefficient vector is linearized; delta r_GNSS，δv_GNSSRespectively representing a position correction vector and a speed correction vector of the antenna phase center of the GNSS receiver; t is t_r,sys，

And

respectively representing the receiver clock offset in m, the receiver clock drift and the satellite clock drift in m/s, the subscript sys representing the corresponding satellite navigation system β_fIs an ionospheric projection function; i is_reIndicating an ionospheric residual error; m, Δ tron_z,wRespectively representing troposphere projection coefficients and zenith troposphere wet delay residual errors; ucd_r,fRepresenting the uncorrected pseudo-range delay on the frequency f at the receiver end; n is a radical of_floatThe floating ambiguity comprising the uncorrected phase delay and the initial phase deviation of the receiver and the satellite end is represented; epsilon₁、ε₂、ε₃Respectively representing unmodeled errors and noises in pseudo-range, phase and Doppler observation; λ represents the carrier wavelength at frequency f.

Further, the step S4 specifically includes the following steps:

for each 5G base station, acquiring a first fixed value of the non-differential ambiguity of the base station and each tracking satellite, collecting a first fixed value of the non-differential ambiguity of the other end 5G base station of the triangulation network connecting line containing the 5G base station and each tracking satellite, and acquiring a second fixed value of the double-differential ambiguity of the common-view satellites between the base stations corresponding to the 5G base station by taking the 5G base station as a reference station and the satellite with the largest elevation angle in the common-view satellites of the other end 5G base station of the triangulation network connecting line of the 5G base station and the reference satellite.

Further, in step S5, when the tracking satellite of the 5G base station has a week skip, the non-difference integer ambiguity second fixed value flag corresponding to the satellite is cancelled, and the estimation returns to step S3 to re-estimate until the equality determination is passed.

Further, in step S1, the established topology of the dironi triangle network of the 5G base station is stored in each 5G base station, and the topology of the dironi triangle network of the 5G base station is updated when a new 5G base station is installed or an existing 5G base station exits from service, and each 5G base station is notified to update.

The invention has the beneficial effects that:

1) according to the invention, high-precision cooperative positioning between vehicles is realized on the basis of GNSS high-precision positioning by combining with a 5G communication D2D technology, so that after user vehicles around an emergency vehicle receive position information of the emergency vehicle, the user vehicles around the emergency vehicle can be actively and ahead avoided by matching with a navigation map, and the influence on emergency vehicle disaster relief and rescue people caused by the blockage of an emergency vehicle passage is avoided. In addition, after the traffic department acquires the high-end precision position information of the vehicle, the traffic indicator lamp can be accurately regulated and controlled, so that precious rescue time is strived for traffic evacuation of emergency vehicles.

2) Compared with the prior art that the positioning precision of the ppp in a short period is not high and the pressure of the service end is too high when a large number of users access the ppp by using the rtk mode, the invention effectively solves two problems in the prior art by combining the terminal direct technology and the Internet of vehicles: the positioning precision in the ppp short term is not high; the rtk method is used to make the server over-stressed when a large number of users access the system.

Drawings

FIG. 1 is a flow chart of the method for 5G communication-based collaborative navigation positioning between vehicles according to the present invention;

FIG. 2 is a schematic diagram of a Diloney triangulation network division of a 5G base station network according to the present invention;

FIGS. 3(a) - (b) are flowcharts of acquiring non-integer ambiguity second fixed values between each 5G base station and each tracking satellite according to the present invention;

FIG. 4 is a schematic diagram of the relative positioning of a vehicle to its access 5G base station according to the present invention;

FIG. 5 is a schematic diagram of the present invention, wherein the vehicle A is used as a center vehicle, and a topology diagram of the information of the vehicles around the same 5G base station is accessed with the center vehicle, and a schematic diagram of the vehicle A and the vehicles around the other accessed 5G base stations are co-located;

fig. 6 is a schematic diagram of vehicle position information sharing based on the 5G communication D2D technology provided by the present invention.

Detailed Description

The invention is further described below with reference to the accompanying drawings and examples, it being understood that the examples described below are intended to facilitate the understanding of the invention, and are not intended to limit it in any way.

The inter-vehicle collaborative navigation positioning method based on GNSS high-precision positioning and combined with the 5G communication D2D technology provided by the embodiment of the invention can assist in realizing active obstacle avoidance between vehicles, and relates to a 5G base station carrying a GNSS receiver and a vehicle carrying the GNSS receiver and provided with a 5G communication module.

The embodiment of the invention provides an giving behavior example of emergency vehicles such as an ambulance, a fire truck and the like, and as shown in figure 1, a 5G communication-based inter-vehicle collaborative navigation positioning method comprises the following steps:

s1: 5G base station for maintaining and updating topology network

As shown in fig. 2, for all 5G base station networks, a 5G base station network is formed according to the dironi triangulation principle, and the network topology is stored in each 5G base station. The topological network is updated when a new 5G base station is erected or the existing 5G base station is out of service (such as being influenced by natural disasters and equipment faults), and each 5G base station is informed to update.

S2: in a static mode, acquiring a first fixed value of double-difference ambiguity of a common-view satellite between each 5G base station pair, wherein the base station pair is composed of a pair of 5G base stations at any two ends of a triangulation network connection line of a 5G base station network topology structure.

According to the 5G base station network topological structure, each 5G base station collects GNSS receiver observation data, collects GNSS receiver observation data of each 5G base station at the other end of the triangulation network connecting line containing the 5G base station, selects the 5G base station as a reference station, selects a satellite with the largest elevation angle in the common visible satellites of the 5G base station and the other end of the 5G base station connecting line of the 5G base station and the triangulation network as a reference satellite, forms a (inter-satellite-inter-station) double-difference observation value, carries out resolving base line on all base station pairs according to a static mode, and obtains a first fixed value of the double-difference ambiguity of the common view satellite between the base station pairs.

Wherein, the double-difference observation equation is as follows:

in the formula (I), the compound is shown in the specification,

representing the carrier phase double-difference observations as a result of differencing between the 5G base station and the common-view satellite,the double differences of the satellite distance between the 5G base station and the common-view satellite are calculated,

the ambiguity of the whole circle is obtained by double difference between the 5G base station and the common-view satellite,

the ionospheric and tropospheric errors are respectively expressed by double differences between the 5G base station and the common-view satellite, and f and c respectively express the signal frequency and the light speed.

S3: acquiring a one-day static coordinate of each 5G base station and a first fixed value of non-difference integer ambiguity of the 5G base station and each tracking satellite

For each 5G base station, acquiring observation data of a GNSS receiver of the base station, combining correction numbers such as precision satellite orbit, clock error and phase deviation and the like broadcast by a satellite-based augmentation system or a wide-area real-time precision positioning system, and estimating and acquiring single-day static coordinates of the 5G base station and first fixed values of non-error integer ambiguity of the 5G base station and each tracking satellite thereof according to a single-day static mode by adopting a non-error precision single-point positioning technology and a non-error ambiguity fixing technology PPP-AR. The single-day static coordinates of the 5G base stations participate in the baseline resolution of the base station pairs.

Wherein, the non-differential GNSS precise single-point positioning observation model is

In the formula (I), the compound is shown in the specification,

the O-C values (updated-Minus-Computed) of the pseudo-range, phase and Doppler observation vector are respectively expressed, each error corrected by using a model is contained, and the subscript f represents the corresponding frequency;

the coefficient vector is linearized; delta r_GNSS，δv_GNSSRespectively correcting a position vector and a speed vector of a phase center of the GNSS antenna; t is t_r,sys，

And

respectively representing the receiver clock offset in m, the receiver clock drift and the satellite clock drift in m/s, the subscript sys representing the corresponding satellite navigation system β_fIs an ionospheric projection function; i is_reIndicating an ionospheric residual error; m, Δ tron_z,wRespectively representing troposphere projection coefficients and zenith troposphere wet delay residual errors; ucd_r，fMeans for expressing an uncorrected pseudorange delay at the receiver end f frequency; n is a radical of_floatThe floating ambiguity comprising the uncorrected phase delay and the initial phase deviation of the receiver and the satellite end is represented; because the change rates of errors such as an ionosphere, a troposphere, hardware delay and the like have little influence on speed measurement by using a Doppler observed value, the third formula in the formulas omits the error correction of the items; epsilon₁、ε₂、ε₃Respectively representing unmodeled errors and noises in pseudo-range, phase and Doppler observation; λ represents the carrier wavelength of the f frequency.

S4: based on the 5G base stations at the two ends of the base station pair and the first fixed values of the non-differential integer ambiguity of each tracking satellite, the second fixed values of the double-differential ambiguity of the common-view satellite between the base station pair are obtained

For each 5G base station, acquiring a first fixed value of the non-differential ambiguity of the base station and each tracking satellite, collecting a first fixed value of the non-differential ambiguity of the other end 5G base station of the triangulation network connecting line containing the 5G base station and each tracking satellite, and acquiring a second fixed value of the double-differential ambiguity of the common-view satellite between the base station pair corresponding to the 5G base station by taking the 5G base station as a reference station and the satellite with the largest elevation angle in the common visible satellites of the other end 5G base station of the triangulation network connecting line of the 5G base station and the base station as a reference satellite.

S5: and carrying out equal judgment on the first fixed value of the double-difference ambiguity of the common-view satellite between each 5G base station pair and the second fixed value of the double-difference ambiguity of the common-view satellite between the corresponding 5G base station pair. If yes, go to step S6; otherwise, the second fixed value mark of the non-difference integer ambiguity between the 5G base station and each tracking satellite thereof is cancelled, the second fixed value mark is used as an unknown parameter again, and the step S3 is returned to re-estimate the first fixed value of the non-difference integer ambiguity between the 5G base station and each tracking satellite thereof until the equal judgment is passed. In addition, for the satellite with the cycle slip, the non-difference integer ambiguity second fixed value flag corresponding to the satellite needs to be cancelled, and the estimation returns to step S3 to be re-estimated. According to the invention, whether the first fixed value of the non-differential integer ambiguity is correct or not can be checked by comparing the first fixed value of the double-differential ambiguity with the second fixed value of the double-differential ambiguity.

S6: and simultaneously marking the first fixed value of the non-differential integer ambiguity of each 5G base station and each tracking satellite thereof as a second fixed value of the non-differential integer ambiguity of each 5G base station and each tracking satellite thereof, and taking the second fixed value as a known value to be substituted into the phase observation value of the 5G base station, thereby obtaining a phase measurement pseudorange observation value Carrier-range of the 5G base station, which does not contain ambiguity parameters. And broadcasting the measured pseudorange observed value Carrier-range without ambiguity parameters to user vehicles accessed to the 5G base station, including ordinary user vehicles and emergency vehicles needing to be avoided. Because the whole-cycle ambiguity data volume is large, the spread data volume can be effectively reduced by broadcasting the measured pseudorange observed value Carrier-range without ambiguity parameters, and the transmission efficiency is improved.

Fig. 3(a) - (b) show a flow chart for acquiring a second fixed value of non-integer ambiguity between each 5G base station and each tracking satellite thereof. Fig. (a) shows a 5G base station A, B, C, D and co-view satellites I and J, and fig. (b) shows an example acquisition process of a second fixed value of non-differential integer ambiguity, specifically including the following steps:

1) for each of the 5G base stations A, B, C, D, GNSS receiver observation data of each 5G base station is acquired, and in combination with corrections of the orbit, clock offset and phase offset of a precision satellite broadcast by a satellite-based augmentation system or a wide-area real-time precision positioning system, a non-differential GNSS precision single-point positioning technique and a non-differential ambiguity fixing technique PPP-AR are employed to acquire the coordinates of each 5G base station and a first fixed value of the non-differential integer ambiguity of each 5G base station and its tracking satellite, which are N (a, I,1), N (a, J,1), N (B, I,1), N (B, J,1), N (C, I,1), N (C, J,1), N (D, I,1), N (D, J,1) according to the single-day static mode estimation.

2) And for each 5G base station, collecting the first fixed value of the non-differential ambiguity of the 5G base station at the other end of each triangulation network connecting line containing the 5G base station through the obtained first fixed value of the non-differential integer ambiguity. And taking the 5G base station A as a reference station, and the satellite with the largest elevation angle in the 5G base station A and the other end 5G base station (B, C, D) connected with the triangulation network as a reference satellite, and firstly making single difference between the satellites to obtain fixed values of single difference ambiguity between the satellites, wherein the fixed values are respectively N (A, IJ,1), N (B, IJ,1), N (C, IJ,1) and N (D, IJ, 1). And performing double difference between stations to obtain second fixed values of double-difference ambiguity, namely N (AB, IJ,2), N (AC, IJ,2) and N (AD, IJ, 2).

3) According to a 5G base station network topological structure, each 5G base station collects GNSS receiver observation data, and collects the GNSS receiver observation data of the other end 5G base station of each triangular network connecting line containing the 5G base station, the 5G base station A is selected as a reference station, the satellite with the largest elevation angle in the 5G base station and the other end 5G base station (B, C, D) connecting the other end commonly seen satellite (I, J) is selected as a reference satellite, a (inter-satellite-inter-station) double-difference observation value is formed, all base station-base station pairs are subjected to baseline solution according to a static mode, and first fixed values of the double-difference ambiguity of the co-view satellite between the base station pairs are obtained and are respectively N (AB, IJ,1), N (AC, IJ,1) and N (AD, IJ, 1).

4) And (3) carrying out equal judgment on the first fixed value of the double-difference ambiguity of the common-view satellite between each 5G base station pair and the second fixed value of the double-difference ambiguity of the common-view satellite between the corresponding 5G base station pair:

when the equal determination is passed, simultaneously marking the first fixed value of the non-difference integer ambiguity of each 5G base station and each tracking satellite thereof as the second fixed value of the non-difference integer ambiguity of the 5G base station and each tracking satellite thereof. And after obtaining the second fixed value of the non-differential integer ambiguity between the 5G base station and each tracking satellite, substituting the second fixed value of the non-differential integer ambiguity into the phase observation value of the 5G base station as a known value so as to obtain a phase measurement pseudorange observation value of the 5G base station without ambiguity parameters, and broadcasting the phase measurement pseudorange observation value to all vehicles accessing the 5G base station.

S7: as shown in fig. 4, each vehicle collects observation data acquired by a GNSS receiver equipped in the vehicle, and accesses a certain 5G base station to acquire a Carrier-range of a measured pseudorange observation value of the vehicle, and then uses the 5G base station as a reference station, and uses a satellite (I, J) with the largest elevation angle among satellites visible to the vehicle and the 5G base station as a reference satellite to form a double-difference observation value, and performs baseline resolution according to a dynamic mode to acquire high-precision position information of the vehicle, and transmits the high-precision position information back to the 5G base station.

S8: each 5G base station collects high-precision position information of vehicles accessing the 5G base station and all the other end 5G base stations accessing the triangulation network connection including the 5G base station, acquires position information of surrounding vehicles within a certain radius (for example, 100 meters) with emergency vehicles such as ambulances and fire trucks as center vehicles, and reports the position information to the center vehicle and the surrounding vehicles. It should be noted that, in the compromise between the data amount of the "certain radius" and the end-to-end communication distance of the vehicle, the data communication pressure is large due to the wide range of the end-to-end communication distance of the vehicle, and the data processing pressure of the central vehicle is large, which are not compatible.

S9: as shown in fig. 5 and 6, after each center vehicle a knows the location information of its surrounding vehicles, it directly uses the technology D2D in 5G communication to establish the communication between the center vehicle a and its surrounding vehicles.

S10: each central vehicle is contacted with the nearest 5G base station at any moment, data updating and transmission are carried out, the position information of the surrounding vehicles (particularly emergency vehicles such as an ambulance, a fire truck and the like needing to be avoided) is updated in real time, and the cooperative navigation positioning between the central vehicle and the surrounding vehicles is realized. In the embodiment, after the user vehicles around the emergency vehicle receive the position information of the emergency vehicle, the user vehicles around the emergency vehicle are actively avoided in advance by being matched with the navigation map, and the situation that the emergency vehicle disaster relief and rescue people are influenced by blocking the emergency vehicle passing path is avoided. On the other hand, after the traffic department acquires the high-end precision position information of the vehicle, the traffic indicator lamp can be accurately regulated and controlled, so that precious rescue time is strived for traffic evacuation of emergency vehicles.

It will be apparent to those skilled in the art that various modifications and improvements can be made to the embodiments of the present invention without departing from the inventive concept thereof, and these modifications and improvements are intended to be within the scope of the invention.