阅读说明：本技术 一种基于三天线的gnss姿态实时测量装置及测量方法 (GNSS attitude real-time measuring device and measuring method based on three antennas ) 是由 刘恩晓 许建华 杜会文 张超 王峰 向长波 刘德鹏 于 2019-11-28 设计创作，主要内容包括：本发明公开了一种基于三天线的GNSS姿态实时测量装置及测量方法,属于测量测绘技术领域。本发明采用三天线的GNSS接收机结构,通过测量3个天线接收到的GNSS卫星信号的载波相位差值来获得天线所在平面的方位角、俯仰角和横滚角；由于卫星信号实时更新和解算,因此不存在误差累积的问题,并且能够实现高精度的实时姿态测量,集定位、测姿于一身；3个天线位置任意摆放,不受天线几何形状限制,相比单点定位等姿态测量系统,精度高,实时性好；相比双天线RTK接收机能够获得三维姿态角度；本发明利用GNSS信号进行位置、基线、姿态解算,系统可自动计算出方位角、俯仰角和横滚角。(The invention discloses a GNSS attitude real-time measuring device and method based on three antennas, and belongs to the technical field of surveying and mapping. The invention adopts a GNSS receiver structure with three antennas, and obtains the azimuth angle, the pitch angle and the roll angle of the plane where the antennas are located by measuring the carrier phase difference of GNSS satellite signals received by 3 antennas; because the satellite signals are updated and solved in real time, the problem of error accumulation does not exist, high-precision real-time attitude measurement can be realized, and positioning and attitude measurement are integrated; the 3 antennas are randomly placed, are not limited by the geometric shapes of the antennas, and have high precision and good real-time performance compared with attitude measurement systems such as single-point positioning and the like; compared with a double-antenna RTK receiver, the three-dimensional attitude angle can be obtained; according to the invention, the GNSS signals are utilized to resolve the position, the baseline and the attitude, and the system can automatically calculate the azimuth angle, the pitch angle and the roll angle.)

1. The utility model provides a GNSS gesture real-time measurement device based on three antennas which characterized in that: the system comprises 3 double-frequency antennas, 3 paths of radio frequency front ends, 3 paths of intermediate frequency sampling units, 3 paths of baseband resolving units, 2 RTK baseline resolving units and 1 attitude resolving unit;

a dual-band antenna configured for receiving GPS/Beidou navigation satellite L1/B1 and L2/B2 navigation signals;

the radio frequency front end is configured to perform low noise amplification and band-pass filtering processing on the received navigation signal, suppress out-of-band interference, and perform frequency mixing through the frequency mixing module to obtain an intermediate frequency signal;

the intermediate frequency processing unit is configured to sample the intermediate frequency signal, convert the intermediate frequency signal into a digital intermediate frequency signal, track the navigation signal and prepare for baseband resolving;

the base band resolving unit is configured to demodulate the code phase and the carrier phase information to obtain a pseudo range, and position and time data are obtained through pseudo range resolving;

the RTK baseline resolving unit comprises a first baseline resolving unit and a second baseline resolving unit; the carrier ambiguity calculation method is configured for solving carrier phase and carrier integer ambiguity and calculating a baseline vector between two antennas;

and the attitude calculation unit is configured to calculate an azimuth angle, a pitch angle and a roll angle of a coordinate system formed by the three antennas to obtain an attitude angle.

2. A GNSS attitude real-time measurement method based on three antennas is characterized in that: the GNSS attitude real-time measurement apparatus based on three antennas as claimed in claim 1, specifically comprising the steps of:

step 1: the three dual-frequency antennas synchronously receive navigation signals of L1/B1 and L2/B2 of a GPS/Beidou navigation satellite, and the navigation signals are transmitted to the radio frequency front end of the receiver in three paths through low-loss feeder lines;

step 2: the three paths of radio frequency front ends respectively perform low noise amplification and band-pass filtering processing on the received signals, inhibit out-of-band interference, and perform frequency mixing through a frequency mixing module to obtain intermediate frequency signals;

and step 3: the intermediate frequency processing unit samples the intermediate frequency signal, converts the intermediate frequency signal into a digital intermediate frequency signal, and then respectively locks frequency and phase of a pseudo-random code sequence and a carrier wave through a phase-locked loop (PLL) and a Delay Locked Loop (DLL) in the intermediate frequency processing unit to obtain code phase and carrier phase information and complete tracking of a navigation signal;

and 4, step 4: the baseband resolving unit demodulates the code phase and carrier phase information to obtain pseudo-range, and position and time data are obtained through pseudo-range resolving;

and 5: the RTK baseline resolving unit calculates the integer ambiguity of two paths of signal carriers through a double-frequency model, and obtains a baseline vector (x) between two antennas in combination with the carrier phase₁,y₁,z₁) And (x)₂,y₂,z₂)；

Step 6: the two RTK baseline resolving units send the two baseline vector information to the attitude resolving unit, and three-dimensional attitude angles including an azimuth angle yaw, a pitch angle tilt and a roll angle are calculated through the three-dimensional attitude angles; the calculation formula is as follows:

yaw＝yaw1 (1)；

tilt＝tilt1 (2)；

wherein yaw1 is the first baseline solution unit output baseline (x)₁,y₁,z₁) The azimuth 1, tilt1 is the output baseline (x) of the first baseline solution unit₁,y₁,z₁) Pitch angle 1;

wherein the calculation process of x, y and z is as follows:

let yaw2 be the output baseline (x) of the second baseline solution unit₂,y₂,z₂) Is the output baseline (x) of the second baseline solution unit₂,y₂,z₂) Pitch angle 2, the calculation formula is as follows:

is provided with

wherein:

wherein the content of the first and second substances,

the expression of x, y, z is as follows:

Technical Field

The invention belongs to the technical field of measurement, and particularly relates to a GNSS attitude real-time measurement device and a GNSS attitude real-time measurement method based on three antennas.

Background

With the development of unmanned systems and intelligent equipment, the attitude becomes an indispensable measurement parameter of the system, so that inertial navigation systems are adopted in large quantities for measuring the attitude parameter of the system.

The inertial navigation system is widely used as an attitude sensor because of high accuracy (attitude accuracy is less than 1 degree), but because the inertial navigation system calculates an attitude angle in an integral mode, attitude information accumulates errors along with time, so that the errors are larger and larger, finally, the system is influenced by the overlarge errors, the attitude information is unavailable, a calibration source needs to be input regularly for periodic calibration, the calibration source cannot be input under a plurality of application conditions, and the calibration source also has unreliability.

With the research of high-precision positioning counter methods such as single-point positioning, differential positioning, real-time (RTK) and the like, a receiver based on GNSS signals is also used for attitude measurement and direction finding, but the current attitude measurement adopts a multi-receiver and single-point positioning mode, and requires large antenna spacing, but the accuracy of attitude measurement results is low, and the cost is high; at present, most RTK-based receivers support double antennas, only direction finding can be achieved, and three-dimensional postures cannot be measured.

Currently, inertial navigation systems, such as gyroscopes and accelerometers, are adopted in real-time three-dimensional attitude measurement systems, and inertial navigation has two problems: firstly, the price is high, and the cost of the fiber optic gyroscope is hundreds of thousands of millions; secondly, the attitude drifts, and the errors of the gyroscope and the accelerometer are accumulated continuously along with the time and cannot be eliminated. For long-term unattended equipment such as the sea, the angle drift of the attitude and the heading can accumulate day by day along with the time, the performance can not meet the use requirement, and the risk that the equipment can not be predicted is brought. The existing product utilizes Real-time kinematic (RTK) carrier difference technology to resolve a double-antenna baseline vector to obtain an azimuth angle and a pitch angle of a baseline, but cannot obtain a roll angle of a three-dimensional attitude.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides the GNSS attitude real-time measuring device and the GNSS attitude real-time measuring method based on the three antennas, which are reasonable in design, overcome the defects of the prior art and have good effects.

In order to achieve the purpose, the invention adopts the following technical scheme:

a GNSS attitude real-time measuring device based on three antennas comprises 3 double-frequency antennas, 3 paths of radio frequency front ends, 3 paths of intermediate frequency sampling units, 3 paths of baseband resolving units, 2 RTK baseline resolving units and 1 attitude resolving unit;

a dual-band antenna configured for receiving GPS/Beidou navigation satellite L1/B1 and L2/B2 navigation signals;

the radio frequency front end is configured to perform low noise amplification and band-pass filtering processing on the received navigation signal, suppress out-of-band interference, and perform frequency mixing through the frequency mixing module to obtain an intermediate frequency signal;

the intermediate frequency processing unit is configured to sample the intermediate frequency signal, convert the intermediate frequency signal into a digital intermediate frequency signal, track the navigation signal and prepare for baseband resolving;

the base band resolving unit is configured to demodulate the code phase and the carrier phase information to obtain a pseudo range, and position and time data are obtained through pseudo range resolving;

the RTK baseline resolving unit comprises a first baseline resolving unit and a second baseline resolving unit; the carrier ambiguity calculation method is configured for solving carrier phase and carrier integer ambiguity and calculating a baseline vector between two antennas;

and the attitude calculation unit is configured to calculate an azimuth angle, a pitch angle and a roll angle of a coordinate system formed by the three antennas to obtain an attitude angle.

In addition, the invention also provides a GNSS attitude real-time measurement method based on three antennas, which adopts the GNSS attitude real-time measurement device based on three antennas, and specifically comprises the following steps:

step 1: the three dual-frequency antennas synchronously receive navigation signals of L1/B1 and L2/B2 of a GPS/Beidou navigation satellite, and the navigation signals are transmitted to the radio frequency front end of the receiver in three paths through low-loss feeder lines;

step 2: the three paths of radio frequency front ends respectively perform low noise amplification and band-pass filtering processing on the received signals, inhibit out-of-band interference, and perform frequency mixing through a frequency mixing module to obtain intermediate frequency signals;

and step 3: the intermediate frequency processing unit samples the intermediate frequency signal, converts the intermediate frequency signal into a digital intermediate frequency signal, and then respectively locks frequency and phase of a pseudo-random code sequence and a carrier wave through a phase-locked loop (PLL) and a Delay Locked Loop (DLL) in the intermediate frequency processing unit to obtain code phase and carrier phase information and complete tracking of a navigation signal;

and 4, step 4: the baseband resolving unit demodulates the code phase and carrier phase information to obtain pseudo-range, and position and time data are obtained through pseudo-range resolving;

and 5: the RTK baseline resolving unit calculates the integer ambiguity of two paths of signal carriers through a double-frequency model, and obtains a baseline vector (x) between two antennas in combination with the carrier phase₁,y₁,z₁) And (x)₂,y₂,z₂)；

Step 6: the two RTK baseline resolving units send the two baseline vector information to the attitude resolving unit, and three-dimensional attitude angles including an azimuth angle yaw, a pitch angle tilt and a roll angle are calculated through the three-dimensional attitude angles; the calculation formula is as follows:

yaw＝yaw1 (1)；

tilt＝tilt1 (2)；

wherein yaw1 is the first baseline solution unit output baseline (x)₁,y₁,z₁) The azimuth 1, tilt1 is the output baseline (x) of the first baseline solution unit₁,y₁,z₁) Pitch angle 1;

wherein the calculation process of x, y and z is as follows:

let yaw2 be the output baseline (x) of the second baseline solution unit₂,y₂,z₂) Is the output baseline (x) of the second baseline solution unit₂,y₂,z₂) Pitch angle 2, the calculation formula is as follows:

is provided with

Corresponding unit baseline vector of

Corresponding unit baseline vector of

Then

Expressed as:

wherein:

wherein the content of the first and second substances,are all unit vectors that are used as the basis,

in that

Projection vector in direction

The expression is shown in formula (10):

in that

Projection vector in vertical direction

The expression is shown in formula (11):

the expression of x, y, z is as follows:

the invention has the following beneficial technical effects:

the invention adopts a GNSS receiver structure with three antennas, and obtains the azimuth angle, the pitch angle and the roll angle of the plane where the antennas are located by measuring the carrier phase difference of GNSS satellite signals received by 3 antennas; because the satellite signals are updated and solved in real time, the problem of error accumulation does not exist, high-precision real-time attitude measurement can be realized, and positioning and attitude measurement are integrated; the 3 antennas are randomly placed, are not limited by the geometric shapes of the antennas, and have high precision and good real-time performance compared with attitude measurement systems such as single-point positioning and the like; compared with a dual-antenna RTK receiver, the three-dimensional attitude angle can be obtained.

The invention utilizes GNSS signals to resolve the position, the baseline and the attitude, and the system can automatically calculate the azimuth angle, the pitch angle and the roll angle, wherein the azimuth angle precision is 0.1 degree @1m, namely the azimuth angle precision reaches 0.1 degree under the condition of 1m, and the pitch angle and the roll angle are 0.2 degree @1 m.

Drawings

Fig. 1 is a schematic structural diagram of a GNSS attitude real-time measurement apparatus based on three antennas.

FIG. 2 is a schematic diagram illustrating the definitions of azimuth, pitch, and roll.

FIG. 3 is a schematic view of vector projection and orthogonalization.

Detailed Description

The invention is described in further detail below with reference to the following figures and detailed description:

the core of the invention is an attitude calculation unit, the attitude calculation algorithm does not depend on the geometric construction of the antenna, and the attitude angle is obtained through orthogonal projection calculation, so that the orthogonal vector of the antenna connecting line is not needed, the positions of the three antennas can be randomly placed, and only the non-collinear triangle can be formed. The baseline resolving unit 1 outputs a baseline (x) without setting the system output azimuth angle as yaw, the pitch angle as tilt and the roll angle as roll₁,y₁,z₁) Azimuth angle 1 of (1) is yaw1 ═ θ₁The base line resolving unit 1 outputs a base line (x)₁,y₁,z₁) Is a pitch angle 1 of

The baseline resolving unit 2 outputs a baseline (x)₂,y₂,z₂) The azimuth angle 2 is yaw2 ═ θ₂The base line resolving unit 2 outputs a base line (x)₂,y₂,z₂) Is at a pitch angle 2 of

Then there are:

yaw＝yaw1 (1)；

tilt＝tilt1 (2)；

wherein the calculation process of x, y and z is as follows:

is provided withCorresponding unit baseline vector of

The definition of the angle is shown in figure 2,

corresponding unit baseline vector ofAs shown in fig. 3, then

Expressed as:

wherein the calculation process of x, y and z is as follows:

let yaw2 be the output baseline (x) of the second baseline solution unit₂,y₂,z₂) Is the output baseline (x) of the second baseline solution unit₂,y₂,z₂) Pitch angle 2, the calculation formula is as follows:

is provided with

Corresponding unit baseline vector of

Corresponding unit baseline vector of

ThenExpressed as:

wherein:

wherein the content of the first and second substances,

are all unit vectors that are used as the basis,

in that

Projection vector in direction

The expression is shown in formula (10):

in that

Projection vector in vertical direction

The expression is shown in formula (11):

the expression of x, y, z is as follows:

it is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.