CN115453601A - Airborne double-antenna GNSS and MINS combined navigation system and navigation method - Google Patents

Abstract

The invention relates to the technical field of navigation, in particular to an airborne double-antenna GNSS and MINS combined navigation system, which comprises an inertial data measuring module, an airborne double-antenna module, an attitude resolving module, an error compensation module, a calculation module, a GNSS signal analysis module and a ground control terminal, wherein the GNSS signal analysis module is used for judging whether a current GNSS signal is available or not, and if the current GNSS signal is not available, the current GNSS signal is sent to the ground control terminal and is unavailable; and after the ground control terminal receives the current GNSS signal and is unavailable, calling historical navigation data of the current machine body position, judging whether the current machine body airborne double-antenna module breaks down or not according to the historical navigation data, and if so, sending a fault signal to the GNSS signal analysis module. The invention can judge whether the airborne double-antenna module has a fault more accurately under the condition that the machine body cannot receive satellite signals or the received satellite signals do not meet the precision requirement. The invention also discloses an airborne double-antenna GNSS and MINS combined navigation method.

Description

An airborne dual-antenna GNSS and MINS integrated navigation system and navigation method

technical field

The invention relates to the technical field of navigation, in particular to an airborne dual-antenna GNSS and MINS combined navigation system and navigation method.

Background technique

The Global Navigation Satellite System (GNSS) is a space-based radio navigation system that relies on satellite pseudo-range carrier, ephemeris, time and clock difference information for real-time positioning. Provide users with all-weather three-dimensional coordinates, speed and time information. The advantages of the GNSS system are high precision, stable error and no divergence, but it is easily affected by the surrounding environment, such as trees and buildings, and multipath effects caused by highly reflective objects such as mirrors.

The inertial navigation system (Inertial Navigation System) is an autonomous navigation system that does not depend on external information and does not radiate energy to the outside (such as radio navigation). It mainly uses an inertial measurement unit (IMU) (Inertial measurement unit). Its working environment includes not only the air, the ground, but also underwater. The basic working principle of inertial navigation is based on Newton's laws of mechanics. By measuring the acceleration of the carrier in the inertial reference system, integrating it with time, and transforming it into the navigation coordinate system, the position in the navigation coordinate system can be obtained. Information such as speed, yaw angle and position. Its advantages are that the work does not need to be timed, the installation position is random, and the positioning range is all scenes, but the positioning accuracy is not high, and the error diverges with time. Complementary to GNSS navigation systems.

Currently, the most widely used integrated navigation methods in the aviation field are Global Navigation Satellite System (Global Navigation Satellite System, GNSS) and Inertial Navigation System (Inertial Navigation System, INS). Navigation equipment based on MEMS devices has the advantages of small size, light weight, low power consumption, low price, and more convenient post-maintenance. In the prior art, the integrated navigation system of GNSS and MINS usually includes an inertial data measurement module, an airborne dual antenna module, an attitude calculation module, an error compensation module, and a velocity and position calculation module. However, for the existing combination of GNSS and MINS As far as the navigation system is concerned, its shortcomings are: when the body cannot receive satellite signals or the received satellite signals do not meet the accuracy requirements, it is impossible to accurately judge the position of the body due to the influence of the external environment. The satellite signal cannot be received or the received satellite signal does not meet the accuracy requirement, or the satellite signal cannot be received or the received satellite signal does not meet the accuracy requirement due to the failure of the airborne dual antenna module.

Contents of the invention

One of the purposes of the present invention is to provide an airborne dual-antenna GNSS and MINS integrated navigation system, so that when the body cannot receive satellite signals or the received satellite signals do not meet the accuracy requirements, it can more accurately determine the airborne navigation system. Whether the dual antenna module is faulty.

An airborne dual-antenna GNSS and MINS integrated navigation system, including an inertial data measurement module, the inertial data measurement module is used to collect inertial data and generate the first navigation data of the body;

Airborne dual-antenna module, the airborne dual-antenna module is used to receive GNSS signals and generate data for the second navigation of the body;

An attitude calculation module, the attitude calculation module is used to generate the initial attitude information of the body according to the first navigation data of the body;

An error compensation module, the error compensation module is used to perform error compensation on the initial attitude information of the body generated by the attitude calculation module according to the second navigation data of the body, and generate the attitude information of the body;

A calculation module, the calculation module is used to generate the speed and position information of the body according to the attitude information of the body, and send the speed and position information to the ground control terminal;

Also includes a GNSS signal analysis module, the GNSS signal analysis module is used to determine whether the current GNSS signal is available, if not available, then send the current GNSS signal to the ground control terminal is not available;

The ground control terminal, after receiving the current GNSS signal unavailable, the ground control terminal retrieves the historical navigation data of the current position of the body, and judges whether the airborne dual antenna module of the current body fails according to the historical navigation data, and if so, then Send a fault signal to the GNSS signal analysis module, the historical navigation data includes the historical body receiving the GNSS signal, the initial attitude information of the historical body, the body attitude information after error compensation, and the calculated speed and position information.

The beneficial effects of the present invention are: through the GNSS signal analysis module, it can be judged whether the current GNSS signal is available, if not available, the current GNSS signal is sent to the ground control terminal to be unavailable; through the ground control terminal, when the current GNSS signal is received Afterwards, retrieve the historical navigation data of the current body position, and judge whether the onboard dual-antenna module of the current body breaks down according to the historical navigation data, and if so, send a fault signal to the GNSS signal analysis module.

According to the historical navigation data of the current airframe location, the ground control terminal includes historical airborne dual-antenna module fault-free information, historical GNSS signal reception, historical initial attitude information of the airframe, airframe attitude information after error compensation, and calculated speed and position information, so that it can be more accurately inferred that the airframe cannot receive satellite signals or the reason why the received satellite signals do not meet the accuracy requirements, so that it can be more accurately inferred whether the airborne dual antenna module is faulty.

A preferred embodiment of the present invention is that: the GNSS signal analysis module is used to judge whether the current GNSS signal is available, including that there is no GNSS signal currently, or the accuracy of the current GNSS signal does not meet the requirements.

The beneficial effect is that: whether the current GNSS signal is available includes the situation that there is no GNSS signal at present, that is, the airborne dual-antenna module cannot receive the GNSS signal, or the accuracy of the current GNSS signal does not meet the requirements, so that it cannot be used for error compensation.

之差，判断GNSS信号的精度，其中D为机体两个天线之间的实际安装距离，

为根据两天线的位置坐标，计算得到的两天线的定位距离。A preferred embodiment of the present invention is: the GNSS signal analysis module, by calculating D and

The difference is to judge the accuracy of the GNSS signal, where D is the actual installation distance between the two antennas of the body,

is the positioning distance of the two antennas calculated according to the position coordinates of the two antennas.

之差，可以判断GNSS信号的精度，以此来判断其是否满足融合需求，可用于误差补偿。The beneficial effect is that: by calculating D and

The difference can be used to judge the accuracy of the GNSS signal to determine whether it meets the fusion requirements, which can be used for error compensation.

A preferred embodiment of the present invention is that: the historical navigation data is multiple sets of associated stored navigation data closest to the current body navigation time, and the ground control terminal is used to comprehensively analyze multiple sets of associated stored navigation data, Determine whether the dual-antenna module onboard the current airframe is faulty.

The beneficial effect is that: the historical navigation data is the navigation data of multiple sets of associated storage closest to the navigation time of the current body, and the retrieved historical navigation data is the data closest to the navigation time of the current body. The amount of data analyzed can improve the system response speed. In addition, these data are more reliable as inferences because they are the closest to the current body navigation time; by calling multiple sets of associated stored navigation data, compared with a set of navigation data In other words, the inferred structure is more credible after a comprehensive analysis; each set of data is associated and stored, so that a series of associated data can be queried only by reading the stored data identifier, such as the historical status of the body receiving GNSS signals, historical The initial attitude information of the airframe, the attitude information of the airframe after error compensation, and the calculated speed and position information, etc.; the ground control terminal comprehensively analyzes multiple sets of associated stored navigation data to determine whether the current airborne dual-antenna module has occurred. faults, making the inference results more accurate.

A preferred embodiment of the present invention is that: the historical airframe receiving GNSS signal refers to whether the historical airframe has received the GNSS signal. If the historical airframe has not received the GNSS signal, then the ground control terminal can directly judge the current airborne dual antenna The module has not failed; if the probability that the historical airframes have not received GNSS signals reaches more than 60%, then further analyze the initial attitude information of the remaining historical airframes that received GNSS signals, the airframe attitude information after error compensation, and the calculation speed and position information, if the analysis of the remaining historical airframes that have received GNSS signals does not use the second navigation data received by GNSS signals for error compensation accounts for more than 60%, then it is judged that the current airframe airborne dual-antenna module has not failed; if the history The proportion of airframes receiving GNSS signals is more than 80%, or the proportion of historical airframes receiving GNSS signals is between 60-80%, and the historical airframes receiving GNSS signals use the second navigation data received by GNSS signals. Error compensation, if the error is within the allowable range and the proportion reaches more than 90%, then it is judged that the dual antenna module onboard the current airframe is faulty.

The beneficial effect is: if the historical airframe has not received the GNSS signal, it means that the current airframe has a problem of not being able to receive the GNSS signal, so the ground control terminal can directly judge that it is not caused by the failure of the current airborne dual antenna module. If the probability of the historical airframe not receiving the GNSS signal reaches more than 60%, it means that the historical airframe has not received the GNSS signal. Initial attitude information, airframe attitude information after error compensation, and calculated speed and position information, if the analysis of the remaining historical airframes that received GNSS signals did not use the second navigation data received by GNSS signals for error compensation, it means that the historical airframes received If the accuracy of the GNSS signal does not meet the requirements and is unavailable, it can be inferred that the GNSS signal cannot be received or there is a problem with the received GNSS signal, which leads to the unavailability, rather than the failure of the airborne dual antenna module; if the historical aircraft received the GNSS signal If the ratio of 80% or more, it means that the current location of the aircraft can usually receive GNSS signals, but if the GNSS signal cannot be received at this time, it is judged that the current airborne dual antenna module is faulty, or the historical aircraft has received GNSS signals The proportion is between 60-80%, and the historical airframe that received the GNSS signal uses the second navigation data received by the GNSS signal to perform error compensation, and the error is within the allowable range. More than 90% of the received GNSS signals meet the error compensation accuracy requirements, and there is a small probability that they do not meet the error compensation requirements and are unusable, indicating that the GNSS signal at the current location of the body is good, but the GNSS signal received by the body is currently unavailable. Therefore, it is judged that the dual antenna module onboard the current airframe is faulty.

A preferred embodiment of the present invention is that: the attitude calculation module uses a quaternion to represent the attitude, and the formula is as follows:

Using quaternion to represent the relative conversion relationship between the aircraft system and the navigation system, the quaternion expression of the direction cosine matrix can be obtained as:

Using Euler angles to represent the direction cosine matrix is as follows:

Using quaternions to represent Euler angles:

Quaternion differential equation:

分别是机体围绕载体坐标系x,y,z轴的角速度。in

are the angular velocities of the body around the x, y, and z axes of the carrier coordinate system, respectively.

The beneficial effect is that the quaternion has a small amount of calculation and can overcome the influence of singular values on attitude calculation.

The preferred embodiment of the present invention is: introduce equivalent rotation vector, the differential equation of equivalent rotation vector is:

In order to ensure the accuracy and real-time performance of the solution, the algorithm of "single sample plus the previous cycle" is used to calculate the equivalent rotation vector, and the formula is as follows:

当前时刻的角增量为

Among them, the angular increment at the previous moment is

The angular increment at the current moment is

Solve the above formula to get the quaternion recursive calculation formula:

为t时刻更新后的四元数，

是从t-1到t时刻四元数的变化值。In the formula,

is the updated quaternion at time t,

is the change value of the quaternion from t-1 to time t.

The beneficial effect is that when non-fixed-axis rotation occurs, directly using Euler angles to solve will introduce rotation non-exchangeable errors to affect the accuracy of the solution. Therefore, an equivalent rotation vector is introduced to reduce the impact of errors on accuracy.

The second object of the present invention is to provide an airborne dual-antenna GNSS and MINS integrated navigation method, including collecting inertial data, generating data for the first navigation of the body; receiving GNSS signals, generating data for the second navigation of the body; Using the data to generate the initial attitude information of the body; performing error compensation on the initial attitude information of the body generated by the attitude calculation module according to the second navigation data of the body to generate the attitude information of the body; generating the speed and position information of the body according to the attitude information of the body, and Send the speed and position information to the ground control terminal; it is characterized in that: it also includes judging whether the current GNSS signal is available, if it is not available, then sending the current GNSS signal to the ground control terminal is unavailable, and the ground control terminal is unavailable when receiving the current GNSS signal. After use, retrieve the historical navigation data of the current body position, and judge whether the current airborne dual antenna module fails according to the historical navigation data, if so, send a fault signal to the GNSS signal analysis module, and the historical navigation data includes historical data. The body receives GNSS signals, the initial attitude information of the historical body, the attitude information of the body after error compensation, and the calculated speed and position information.

Through the method of the invention, in the case that the airframe cannot receive satellite signals or the received satellite signals do not meet the accuracy requirements, it can be more accurately judged whether the airborne dual antenna module fails.

Description of drawings

Fig. 1 is a schematic block diagram of an embodiment of the airborne dual-antenna GNSS and MINS integrated navigation system of the present invention.

detailed description

The preferred embodiments of the present invention will be described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described below are only used to explain the present invention and do not limit the protection scope of the present invention.

The terms "first", "second" and the like in the specification, claims, and embodiments of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence.

The present invention is described in further detail below by preferred specific embodiments:

Embodiment one

As shown in Figure 1: the airborne dual-antenna GNSS and MINS integrated navigation system disclosed in this embodiment includes an inertial data measurement module, which is used to collect inertial data and generate the first data for navigation of the body. The inertial data measurement module of this embodiment includes a three-axis accelerometer, a three-axis gyroscope, and a three-axis magnetometer, which measure the specific force acceleration and angular rate in three axial directions of the body, and the three-axis magnetometer measures the heading of the body . The information processing sub-module integrated in the inertial data measurement module performs analog-to-digital conversion, filtering, calibration and other processing on the collected analog signals, and sends the processed first navigation data to the attitude calculation module through the SPI protocol interface.

Airborne dual-antenna module, the airborne dual-antenna module is used to receive GNSS signals and generate the second navigation data of the airframe; the second navigation data described in this embodiment includes latitude and longitude coordinates, heading, and pitch angle data.

An attitude calculation module, the attitude calculation module is used to generate the initial attitude information of the body according to the first navigation data of the body; specifically, the attitude calculation module uses a quaternion to represent the attitude, and the formula is as follows:

Using quaternion to represent the relative conversion relationship between the aircraft system and the navigation system, the quaternion expression of the direction cosine matrix can be obtained as:

Using Euler angles to represent the direction cosine matrix is as follows:

Using quaternions to represent Euler angles:

Quaternion differential equation:

分别是机体围绕载体坐标系x,y,z轴的角速度。in

are the angular velocities of the body around the x, y, and z axes of the carrier coordinate system, respectively.

When non-fixed axis rotation occurs, directly using Euler angles to solve will introduce rotation non-exchangeable errors to affect the accuracy of the solution. Therefore, an equivalent rotation vector is introduced to reduce the impact of the error on the accuracy. The differential equation of the equivalent rotation vector is:

Calculate the equivalent rotation vector, the formula is as follows:

当前时刻的角增量为

Among them, the angular increment at the previous moment is

The angular increment at the current moment is

Solve the above formula to get the quaternion recursive calculation formula:

为t时刻更新后的四元数，

是从t-1到t时刻四元数的变化值。In the formula,

is the updated quaternion at time t,

is the change value of the quaternion from t-1 to time t.

An error compensation module, the error compensation module is used to perform error compensation on the initial attitude information of the body generated by the attitude calculation module according to the second navigation data of the body, and generate the attitude information of the body. In this embodiment, the error compensation of the error compensation module adopts a discrete Kalman filter, and the selection of the state quantity uses an indirect method, that is, the error of the first navigation data of the airframe and the second navigation data of the airframe of the two navigation systems is used as the state quantity. In this embodiment, a discrete Kalman filter is used for error compensation, and an indirect method is used for selection of state quantities. The state equation and the measurement equation are respectively used to reflect the state characteristics of the integrated navigation and the relationship between the measurement information and the state.

The state equation of the integrated navigation system is as follows:

和加速度计相关漂移

作为状态向量(共15维)，如下：Select MINS attitude misalignment angle [φ _E φ _N φ _U ] ^T , velocity error in northeast direction [δv _E δv _N δv _U ] ^T , high latitude and longitude position error [δLδλδh] ^T , gyroscope related drift

and accelerometer related drift

As a state vector (a total of 15 dimensions), as follows:

X(t)＝[φ _E φ _N φ _U δv _E δv _N δv _U

The state transition matrix of the system at time t is:

In the formula, F _I (t) is the error matrix of the inertial navigation system, expressed as the following form:

In the formula, α _s =diag(1/τ _sx 1/τ _sy 1/τ _sz )(s=g,a), 1/τ _si (s=g,a; i=x,y,z) is Mal Cove time-dependent constant.

Choose the random white noise of the gyroscope [w _gεx w _gεy w _gεz ] ^T , the random white noise of the accelerometer [w _aεx w _aεy w _aεz ] ^T , the first-order Markov driving white noise of the gyroscope [η _gx η _gy η _g ] _z ^T and the first-order Markov driven white noise [η _ax η _ay η _az ] ^T of the accelerometer as the noise of the system, so the system noise matrix is:

W(t)＝[w _gεx w _gεy w _gεz w _aεx w _aεy w _aεz η _gx η _gy η _gz η _ax η _ay η _az ]

The covariance matrix P corresponding to the noise matrix is:

The system noise allocation matrix is:

The designed dual-antenna GNSS and MINS integrated navigation system uses nine-dimensional data of position, velocity and attitude data as observation values, and the measurement equation is as follows:

Z(t) _9×1 ＝H(t) _9×15 X(t) _15×1 +R(t) _9×1

为INS解算姿态，

为GNSS和磁力计提供的姿态角。in

Calculate attitude for INS,

Attitude angle provided for GNSS and magnetometer.

H(t)＝[H _Φ (t) _3×15 H _v (t) _3×15 H _p (t) _3×15 ] ^T ,

in,

H _Φ ＝[I _3×3 0 _3×12 ]

H _v ＝[0 _3×3 I _3×3 0 _3×9 ]

H _p ＝[0 _3×6 I _3×3 0 _3×6 ]

Measurement noise matrix R(t)＝[R _Φ (t) R _v (t) R _p (t)] ^T , where R _Φ (t) is the white noise of GNSS and magnetometer, R _v (t) and R _p (t) is the white noise of the velocity and position measurements of the GNSS receiver, respectively.

A calculation module, the calculation module is used to generate the speed and position information of the body according to the attitude information of the body, and send the speed and position information to the ground control terminal. Specifically, the calculation module of this embodiment adopts an integral calculation method. According to the attitude matrix obtained by the attitude calculation, the acceleration in the body coordinate system is converted into the three-axis acceleration in the earth coordinate system. On the basis of the given initial position, the acceleration obtained by the calculation is integrated with respect to time to obtain the velocity. Integrating the velocity again with respect to time yields the position.

之差，判断GNSS信号的精度，其中D为机体两个天线之间的实际安装距离，

为根据两天线的位置坐标，计算得到的两天线的定位距离。GNSS signal analysis module, the GNSS signal analysis module is used to judge whether the current GNSS signal is available, if not available, then send the current GNSS signal unavailable to the ground control terminal. Specifically, the GNSS signal analysis module is used to judge whether the current GNSS signal is available, including that there is currently no GNSS signal, or the accuracy of the current GNSS signal does not meet the requirements. More specifically, the GNSS signal analysis module calculates D and

The difference is to judge the accuracy of the GNSS signal, where D is the actual installation distance between the two antennas of the body,

is the positioning distance of the two antennas calculated according to the position coordinates of the two antennas.

The ground control terminal, after receiving the current GNSS signal unavailable, the ground control terminal retrieves the historical navigation data of the current position of the body, and judges whether the airborne dual antenna module of the current body fails according to the historical navigation data, and if so, then Send a fault signal to the GNSS signal analysis module.

In this embodiment, the historical navigation data includes the historical airframe receiving GNSS signals, the initial attitude information of the historical airframe, the airframe attitude information after error compensation, and the calculated speed and position information. Further, the historical navigation data It is multiple sets of associated stored navigation data closest to the navigation time of the current airframe, and the ground control terminal is used to comprehensively analyze the multiple sets of associated stored navigation data to determine whether the current airborne dual-antenna module is faulty.

The ground control terminal judges whether the airborne dual-antenna module of the current airframe is faulty according to the historical navigation data. The specific analysis method is: the historical airframe receiving the GNSS signal refers to whether the historical airframe has received the GNSS signal. If the historical airframe has not received the GNSS signal signal, the ground control terminal can directly judge that the airborne dual-antenna module of the current airframe has not failed; if the probability that the historical airframe has not received the GNSS signal reaches more than 60%, further analysis of the remaining historical airframes that have received the GNSS signal Initial attitude information, airframe attitude information after error compensation, and calculated speed and position information, if the analysis of the remaining historical airframes that received GNSS signals did not use the second navigation data received by GNSS signals for error compensation accounted for more than 60% , it is judged that the airborne dual-antenna module of the current airframe is not faulty; if the proportion of the historical airframe receiving the GNSS signal reaches more than 80%, or the proportion of the historical airframe receiving the GNSS signal is between 60-80%, and the received The historical airframe of the GNSS signal uses the second navigation data received by the GNSS signal for error compensation. If the error is within the allowable range and the proportion reaches more than 90%, it is judged that the dual antenna module onboard the current airframe is faulty.

This embodiment also discloses an airborne dual-antenna GNSS and MINS integrated navigation method, which includes the following content:

Collect inertial data and generate data for the first navigation of the body;

Receive the GNSS signal and generate the data for the second navigation of the body;

generating the initial attitude information of the body according to the first navigation data of the body;

Performing error compensation on the initial attitude information of the body generated by the attitude calculation module according to the second navigation data of the body to generate the attitude information of the body;

Generate speed and position information of the body according to the attitude information of the body, and send the speed and position information to the ground control terminal;

It also includes judging whether the current GNSS signal is available, if not, then sending the current GNSS signal to the ground control terminal is unavailable, and the ground control terminal retrieves the historical navigation data of the current body position after receiving the current GNSS signal is unavailable, and According to the historical navigation data, it is judged whether the airborne dual-antenna module of the current airframe is faulty, and if so, a fault signal is sent to the GNSS signal analysis module.

In the airborne dual-antenna GNSS and MINS combined navigation method of the present invention, the historical navigation data includes historical airframe airborne dual-antenna module fault-free information, historical airframe reception of GNSS signals, historical airframe initial attitude information, and error-compensated airframe Attitude information, as well as computed velocity and position information.

Embodiment two

The difference between this embodiment and Embodiment 1 is that the airborne dual-antenna GNSS and MINS integrated navigation system in this embodiment also includes a flight status identification module, which is used to utilize The accelerometer performs flight state identification, and the accelerometer output at time k is obtained according to the following formula

时，判定机体处于稳定态，此时的机体为匀速巡航状态或者地面静止状态，此阶段使用加速度计进行姿态误差补偿修正，其中，

为阈值参数，其取值视导航系统所在环境的具体噪声水平设定；当

时，计算水平双轴加速度计的输出

来进行具体飞行状态判定，判定方法如下：when

When , it is determined that the body is in a stable state. At this time, the body is in a constant speed cruising state or a stationary state on the ground. At this stage, the accelerometer is used to correct the attitude error compensation. Among them,

is the threshold parameter, and its value depends on the specific noise level of the environment where the navigation system is located; when

When , calculate the output of the horizontal two-axis accelerometer

To determine the specific flight status, the determination method is as follows:

时，与陀螺仪数据进行结合判定，机体处于转弯状态或者盘旋状态，其中，

为阈值参数，依据水平加速度计的噪声具体取值，when

When , combined with the gyroscope data to determine, the body is in a turning state or a hovering state, wherein,

is the threshold parameter, according to the specific value of the noise of the horizontal accelerometer,

时，机体的机动状态大，处于起飞或者降落阶段。

When , the maneuvering state of the airframe is large, and it is in the stage of take-off or landing.

In the static alignment phase of the airframe, the following formulas are used to obtain the local reference gravity acceleration

The preferred embodiment of the present application has been described in detail above in conjunction with the accompanying drawings. The typical known structures and common knowledge technologies in the preferred embodiment are not described here too much. Those of ordinary skill in the art can learn from the inspiration given by this embodiment. , in combination with one's own ability to perfect and implement the technical solution of the present invention, some typical known structures, known methods or common knowledge technologies should not become obstacles for those of ordinary skill in the art to implement the present application.

The scope of protection required by this application shall be based on the content of the claims, and the content of the invention, specific implementation methods, and the contents recorded in the drawings of the specification are used to interpret the claims.

Within the scope of the technical conception of the present application, some modifications can also be made to the specific embodiments of the present application, and the specific embodiments after these modifications should also be regarded as within the protection scope of the present application.

Claims (8)

1. An airborne double-antenna GNSS and MINS combined navigation system comprises an inertial data measurement module, a first navigation module and a second navigation module, wherein the inertial data measurement module is used for collecting inertial data and generating first navigation data of an organism;

the airborne double-antenna module is used for receiving GNSS signals and generating second navigation data of the body;

the attitude calculation module is used for generating initial attitude information of the engine body according to first navigation data of the engine body;

the error compensation module is used for carrying out error compensation on the initial attitude information of the engine body generated by the attitude calculation module according to the second navigation data of the engine body to generate the attitude information of the engine body;

the computing module is used for generating speed and position information of the body according to the body posture information and sending the speed and position information to the ground control end;

the method is characterized in that: the system also comprises a GNSS signal analysis module, wherein the GNSS signal analysis module is used for judging whether the current GNSS signal is available or not, and if the current GNSS signal is not available, the GNSS signal analysis module sends the current GNSS signal to the ground control terminal;

the ground control end is used for calling historical navigation data of the current position of the engine body after the ground control end receives the current GNSS signal and is unavailable, judging whether the airborne double-antenna module of the current engine body breaks down or not according to the historical navigation data, if so, sending a fault signal to the GNSS signal analysis module, wherein the historical navigation data comprises the situation that the historical engine body receives the GNSS signal, initial attitude information of the historical engine body, attitude information of the engine body after error compensation, and calculated speed and position information.

2. The combined on-board dual-antenna GNSS and MINS navigation system of claim 1, wherein: the GNSS signal analysis module is used for judging whether the current GNSS signal is available or not, wherein the current GNSS signal is not available or the current GNSS signal accuracy does not meet the requirement.

3. According to the rightThe combined airborne dual-antenna GNSS and MINS navigation system of claim 2, wherein: the GNSS signal analysis module calculates the sum D

The difference, determining the accuracy of the GNSS signal, wherein D is the actual installation distance between the two antennas of the body,

the positioning distance of the two antennas is calculated according to the position coordinates of the two antennas.

4. The combined on-board dual-antenna GNSS and MINS navigation system of claim 1, wherein: the ground control end is used for carrying out comprehensive analysis on the multiple groups of navigation data stored in association and judging whether the current machine body airborne double-antenna module breaks down or not.

5. The combined on-board dual-antenna GNSS and MINS navigation system of claim 4, wherein: the condition that the historical engine body receives the GNSS signals means whether the historical engine body receives the GNSS signals, and if the historical engine body does not receive the GNSS signals, the ground control end directly judges that the current engine body airborne double-antenna module does not break down; if the probability ratio of the historical organism not receiving the GNSS signals reaches more than 60%, further analyzing initial attitude information, error-compensated organism attitude information and calculated speed and position information of the historical organism which remains to receive the GNSS signals, and if the probability ratio of the historical organism which remains to receive the GNSS signals and does not adopt the second navigation data received by the GNSS signals to carry out error compensation reaches more than 60%, judging that the current organism airborne double-antenna module does not break down; and if the percentage of the historical organism receiving the GNSS signals reaches more than 80%, or the percentage of the historical organism receiving the GNSS signals is between 60% and 80%, and the historical organism receiving the GNSS signals adopts the second navigation data received by the GNSS signals to compensate errors, and the percentage of the errors is more than 90% in an allowable range, judging that the current airborne double-antenna module of the historical organism fails.

6. The combined on-board dual-antenna GNSS and MINS navigation system of claim 1, wherein: the attitude calculation module adopts quaternion to carry out attitude expression, and the formula is as follows:

expressing the relative conversion relation between a machine system and a navigation system by using quaternion, and obtaining the quaternion expression of a direction cosine matrix as follows:

the directional cosine matrix is represented using euler angles as follows:

expressing the euler angle by quaternion:

quaternion differential equation:

wherein

The angular velocities of the body around the x, y, z axes of the carrier coordinate system, respectively.

7. The combined on-board dual-antenna GNSS and MINS navigation system of claim 6, wherein: introducing an equivalent rotation vector, wherein a differential equation of the equivalent rotation vector is as follows:

calculating an equivalent rotation vector, wherein the formula is as follows:

wherein the angular increment of the previous moment is

The angular increment at the present moment is

Solving the above formula to obtain a quaternion recursion calculation formula:

in the formula,

is the updated quaternion at time t,

is the change in quaternion from t-1 to time t.

8. An airborne double-antenna GNSS and MINS combined navigation method comprises the steps of collecting inertial data and generating first navigation data of an organism; receiving the GNSS signal to generate second navigation data of the body; generating body initial attitude information according to first navigation data of a body; carrying out error compensation on the initial attitude information of the engine body generated by the attitude calculation module according to the second navigation data of the engine body to generate the attitude information of the engine body; generating speed and position information of the body according to the body posture information, and sending the speed and position information to a ground control end; the method is characterized in that: the method comprises the steps of obtaining current GNSS signals, sending the current GNSS signals to a ground control end, calling historical navigation data of the current machine body position after the current GNSS signals are received by the ground control end and judging whether a current machine body airborne double-antenna module breaks down or not according to the historical navigation data, sending fault signals to a GNSS signal analysis module if the current GNSS signals are not available, wherein the historical navigation data comprise the situation that the historical machine body receives the GNSS signals, initial attitude information of the historical machine body, attitude information of the machine body after error compensation, and calculated speed and position information.

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