Disclosure of Invention
The application provides a navigation method and a navigation device, which can improve navigation precision.
The application provides a navigation method, which comprises the following steps:
obtaining a mounting angle of an inertial sensor in an inertial navigation system;
and converting the data under the inertial sensor coordinate system output by the inertial sensor into data under a carrier coordinate system according to the installation angle, and positioning the carrier according to the data under the carrier coordinate system.
Optionally, the obtaining of the installation angle of the inertial sensor in the inertial navigation system includes:
determining the state of the carrier according to the data output by the inertial sensor;
when the carrier is in a static state, determining an initial value of an attitude angle of the carrier;
updating the attitude angle of the carrier according to the initial value of the attitude angle of the carrier;
and when the carrier is in a turning state, judging whether the error of the attitude angle output by the inertial navigation system is converged, and when the error of the attitude angle output by the inertial navigation system is converged, determining the installation angle of the inertial sensor according to the speed output by the satellite navigation system and the speed output by the combined navigation system.
Optionally, the determining the state of the carrier according to the data output by the inertial sensor includes:
when in use
Determining that the carrier is in a static state;
when in use
And is
Determining that the carrier is in a straight-moving state;
when in use
And is
Determining that the carrier is in a turning state;
wherein,
GA
ifor the ith data within a fixed time window, M
iIs the mean of the first i data, M
i-1Is the mean of the first (i-1) data, λ is the first threshold, D
iMean value of the difference of the first i data and the mean value, TD
iIs the average of the sum of squares of the first i angular velocity values,
is the sum of the squares of the ith set of angular velocity values and μ is the second threshold.
Optionally, the updating the attitude angle of the carrier according to the initial value of the attitude angle of the carrier includes:
calculating a first rotation matrix from the inertial sensor coordinate system to a carrier coordinate system according to the initial value of the attitude angle;
converting data under an inertial sensor coordinate system output by the inertial sensor into data under a carrier coordinate system according to the first rotation matrix;
and updating the attitude angle of the carrier according to the data under the carrier coordinate system and the initial value of the attitude angle.
Optionally, the determining the installation angle of the inertial sensor according to the speed output by the satellite navigation system and the speed output by the combined navigation system includes:
determining a first rotation matrix from the inertial sensor coordinate system to a carrier coordinate system according to the speed output by the satellite navigation system and the speed output by the combined navigation system;
determining a mounting angle of the inertial sensor from the first rotation matrix.
Optionally, the determining a first rotation matrix according to the speed output by the satellite navigation system and the speed output by the combined navigation system includes:
determining a second rotation matrix according to the speed output by the satellite navigation system;
determining a third rotation matrix according to the speed output by the integrated navigation system;
and determining a first rotation matrix according to the second rotation matrix and the third rotation matrix.
Optionally, the determining the installation angle of the inertial sensor according to the first rotation matrix includes:
according to the formula
Calculating a mounting roll angle;
according to the formula
Calculating an installation pitch angle;
according to the formula
Calculating an installation course angle;
wherein,
is the first rotation matrix.
Optionally, the positioning the carrier according to the data in the carrier coordinate system includes:
when the satellite navigation system is effectively observed, positioning the carrier according to the data in the carrier coordinate system by adopting a close combination mode;
and when the satellite navigation system fails to observe, positioning the carrier according to the data and the virtual observed quantity in the carrier coordinate system.
Optionally, when the carrier is in a static state, the virtual observation is constructed by a complete constraint that the three-axis speeds are all 0;
when the carrier is in a straight-ahead state or a turning state, the virtual observations are constructed with an incomplete constraint of 0 for both lateral and longitudinal velocities.
The embodiment of the invention provides a navigation method, which comprises the following steps:
when the observation of the satellite navigation system is effective, positioning the carrier by adopting a close combination mode according to data in a carrier coordinate system;
and when the satellite navigation system fails to observe, positioning the carrier according to the data and the virtual observed quantity in the carrier coordinate system.
Optionally, when the carrier is in a static state, the virtual observation is constructed by a complete constraint that the three-axis speeds are all 0;
when the carrier is in a straight-ahead state or a turning state, the virtual observations are constructed with an incomplete constraint of 0 for both lateral and longitudinal velocities.
An embodiment of the present invention provides a navigation device, including:
the acquisition module is used for acquiring the installation angle of an inertial sensor in the inertial navigation system;
and the first navigation module is used for converting data under an inertial sensor coordinate system output by the inertial sensor into data under a carrier coordinate system according to the installation angle, and positioning the carrier according to the data under the carrier coordinate system.
An embodiment of the present invention provides a navigation device, including:
the second navigation module is used for positioning the carrier according to data in a carrier coordinate system by adopting a close combination mode when the satellite navigation system is effectively observed;
and when the satellite navigation system fails to observe, positioning the carrier according to the data and the virtual observed quantity in the carrier coordinate system.
An embodiment of the present invention provides a navigation device, including a processor and a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, and when the instructions are executed by the processor, any one of the above navigation methods is implemented.
An embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps of any of the above-mentioned navigation methods.
Compared with the related art, the method comprises the following steps: obtaining a mounting angle of an inertial sensor in an inertial navigation system; and converting the data under the inertial sensor coordinate system output by the inertial sensor into data under a carrier coordinate system according to the installation angle, and positioning the carrier according to the data under the carrier coordinate system. According to the method and the device, the data under the inertial sensor coordinate system output by the inertial sensor are converted into the data under the carrier coordinate system based on the installation angle of the inertial sensor, and then the carrier is positioned based on the data under the carrier coordinate system, so that errors caused by the installation angle are eliminated, and the navigation precision is improved.
Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the application. The objectives and other advantages of the application may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Detailed Description
To make the objects, technical solutions and advantages of the present application more apparent, embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.
The steps illustrated in the flow charts of the figures may be performed in a computer system such as a set of computer-executable instructions. Also, while a logical order is shown in the flow diagrams, in some cases, the steps shown or described may be performed in an order different than here.
Referring to fig. 1, the present application proposes a navigation method, including:
and step 100, obtaining the installation angle of an inertial sensor in the inertial navigation system. The method comprises the following steps:
determining the state of the carrier according to data output by an inertial sensor in an inertial navigation system;
when the carrier is in a static state, determining an initial value of an attitude angle of the carrier;
updating the attitude angle of the carrier according to the initial value of the attitude angle of the carrier;
when the carrier is in a turning state, whether the error of the attitude angle output by the inertial navigation system is converged or not is judged, and when the error of the attitude angle output by the inertial navigation system is converged, the installation angle of the inertial sensor is determined according to the speed output by the satellite navigation system (such as GNSS, Beidou system or Galileo system) and the speed output by the combined navigation system.
In the present application, the inertial sensor may be a micromechanical inertial sensor. The carrier comprises: missiles, airplanes, satellites, tanks, vehicles, ships, and the like.
In the present application, the data output by the inertial sensor includes: angular velocity values measured by the gyroscope and acceleration values measured by the accelerometer.
In this application, when
Determining that the carrier is in a static state; when in use
And is
When the carrier is in the straight-moving state, determining that the carrier is in the straight-moving state; when in use
And is
And determining that the carrier is in a turning state.
Wherein,
GA
ifor the ith data (arbitrary axis angular velocity value, or arbitrary axis acceleration value) within a fixed time window, M
iIs the mean of the first i data, M
i-1Is the mean of the first (i-1) data,
M 00, λ is a first threshold, D
iThe initial difference of the angular velocity value is D which is the mean value of the difference of the first i data and the mean value
01 radian (rad), the initial difference in acceleration values is D
00.1 meters per second (m/s), TD
iIs the average of the sum of squares of the first i angular velocity values,
is the sum of the squares of the ith set of angular velocity values and μ is the second threshold.
Fig. 2 is a schematic diagram of data output by a three-axis gyroscope and an accelerometer in an actual driving track process. As shown in fig. 2, the horizontal axis represents time, the vertical axis represents output data, and the z-axis acceleration curve, the y-axis acceleration curve, the x-axis acceleration curve, the z-axis angular velocity curve, the y-axis angular velocity curve, and the x-axis angular velocity curve are arranged in this order along the direction of the vertical axis. In fig. 2, the carrier is at rest for the time period between the dashed lines perpendicular to the horizontal axis. The time period during which the carrier is in the stationary state detected by the above-described determination means substantially coincides with the time period shown in fig. 2.
Fig. 3 is a schematic diagram of another data output by an actual gyroscope. As shown in fig. 3, the horizontal axis represents time, the vertical axis represents output data, and the second threshold value curve, the TD curve, the z-axis angular velocity curve, the y-axis angular velocity curve, and the x-axis angular velocity curve are arranged in this order along the direction of the vertical axis. In fig. 3, the carrier is in a turning state during the time between the dashed lines perpendicular to the horizontal axis. The time period during which the carrier is in the turning state detected by the above-described determination means substantially coincides with the time period shown in fig. 3.
In this application, when the carrier is in a static state, the course angle of the carrier is 0.
Wherein determining an initial value of the attitude angle of the carrier comprises:
determining that the initial value of a course angle in the attitude angles of the carrier is 0;
according to the formula
Calculating an initial value of a pitch angle in attitude angles of the carrier;
according to the formula
Calculating an initial value of a roll angle in attitude angles of the carrier;
wherein (f)x,fy,fz) And outputting an acceleration value for the micro inertial sensor, wherein theta is a pitch angle, and gamma is a roll angle.
Wherein the first rotation matrix is:
(ii) a Where ψ is the heading angle.
When the heading angle is 0, the first rotation matrix can be simplified as:
wherein, according to the formula
Converting data under an inertial sensor coordinate system into data under a carrier coordinate system; wherein, GA
bFor data in a carrier coordinate system, GA
mIs data in the inertial sensor coordinate system.
In this application, updating the attitude angle of the carrier according to the initial value of the attitude angle of the carrier includes:
calculating a first rotation matrix from an inertial sensor coordinate system to a carrier coordinate system according to the initial value of the attitude angle; wherein, the three axes of the inertial sensor coordinate system are consistent with the three axes of the gyroscope, the xyz three axes point to the upper front right, and the three axes (namely the xyz three axes) of the carrier coordinate system point to the lower front right of the carrier;
converting data under an inertial sensor coordinate system output by an inertial sensor into data under a carrier coordinate system according to the first rotation matrix;
and updating the attitude angle of the carrier according to the data in the carrier coordinate system and the initial value of the attitude angle.
When the carrier is in a motion state, the carrier enters a loose combination mode, and in the loose combination mode, because the IMU attitude error convergence speed is far lower than the position error convergence speed and the speed error convergence speed, the satellite navigation system external observation needs to be stripped to judge whether the IMU attitude error is converged.
The installation angle of the inertial sensor can be determined according to the speed output by the satellite navigation system and the speed output by the combined navigation system under the condition of good satellite signal quality.
Wherein determining the mounting angle of the inertial sensor based on the speed output by the satellite navigation system and the speed output by the integrated navigation system comprises:
and determining a first rotation matrix according to the speed output by the satellite navigation system and the speed output by the combined navigation system, and determining the installation angle of the inertial sensor according to the first rotation matrix.
Wherein determining the first rotation matrix based on the speed output by the satellite navigation system and the speed output by the integrated navigation system comprises:
determining a second rotation matrix according to the speed output by the satellite navigation system;
determining a third rotation matrix according to the speed output by the integrated navigation system;
and determining the first rotation matrix according to the second rotation matrix and the third rotation matrix, namely the first rotation matrix is the product of the second rotation matrix and the third rotation matrix.
Wherein, according to the formula
Determining a first rotation matrix; wherein,
in order to be the second rotation matrix, the first rotation matrix,
is a third rotation matrix.
Wherein determining the second rotation matrix based on the velocity output by the satellite navigation system comprises:
determining the attitude angle of the carrier according to the speed output by the satellite navigation system;
and determining a second rotation matrix according to the attitude angle of the carrier.
Wherein determining the attitude angle of the carrier based on the velocity output by the satellite navigation system comprises:
since the carrier is generally rarely sideslipped when running straight at a high speed, the roll angle γ of the carrier can be determined to be 0; according to the formula
Calculating the pitch angle of the carrier; according to the formula
Calculating a course angle of the carrier; wherein,
as is the speed of the output of the satellite navigation system,
in order to obtain the speed in the direction of the sky,
in order to be the east-direction speed,
is the north speed.
When the roll angle γ is 0, the first rotation matrix can be simplified as:
therefore, the pitch angle and the course angle obtained by the calculation are substituted into the above formula to obtain a second rotation matrix.
Wherein determining the third rotation matrix from the speed output by the integrated navigation system comprises:
determining the attitude angle of the carrier according to the speed output by the integrated navigation system;
and determining a third rotation matrix according to the attitude angle of the carrier.
Wherein determining the attitude angle of the carrier based on the velocity output by the integrated navigation system comprises:
determining the roll angle gamma of the carrier to be 0; according to the formula
Calculating the pitch angle of the carrier; according to the formula
Calculating a course angle of the carrier; wherein,
in the form of the speed of the GNSS output,
in order to obtain the speed in the direction of the sky,
in order to be the east-direction speed,
is the north speed.
When the roll angle γ is 0, the first rotation matrix can be simplified as:
therefore, the pitch angle and the course angle obtained by the calculation are substituted into the above formula to obtain a third rotation matrix.
Wherein determining the mounting angle of the inertial sensor from the first rotation matrix comprises:
according to the formula
Calculating a mounting roll angle;
according to the formula
Calculating an installation pitch angle;
according to the formula
And calculating an installation heading angle.
Wherein,
in the form of a first rotation matrix, the first rotation matrix,
row 3, column 1 elements of the first rotation matrix, and so on.
And 101, converting data in an inertial sensor coordinate system output by an inertial sensor into data in a carrier coordinate system according to the installation angle, and positioning the carrier according to the data in the carrier coordinate system.
In this application, the positioning of the carrier according to the data in the carrier coordinate system includes:
and when the observation of the satellite navigation system is effective, positioning the carrier by adopting a close combination mode according to the data in the carrier coordinate system.
And when the satellite navigation system observation fails, positioning the carrier according to the data and the virtual observed quantity in the carrier coordinate system.
Specifically, when the carrier is in a static state, the virtual observation is constructed by complete constraint of which the three-axis speeds are all 0;
when the carrier is in a straight-going state or a turning state, the virtual observation quantity is constructed by using an incomplete constraint that the transverse speed (namely the right-direction speed of the carrier coordinate system) and the longitudinal speed (namely the downward speed of the carrier coordinate system) are 0.
According to the method and the device, when the observation of the satellite navigation system fails, the virtual observed quantity is constructed to replace the observed quantity of the satellite navigation system to position the carrier, so that the rapid accumulation of the navigation state errors during the operation of the inertial navigation system is effectively inhibited.
Practice proves that the positioning accuracy in the completely free installation is equivalent to that in the fixed installation by comparing the positioning result in the completely free installation of the inertial sensor (namely the installation angle exists between the three axes of the gyroscope and the three axes of the carrier coordinate system) with the positioning result in the fixed installation (namely the installation angle does not exist between the three axes of the gyroscope and the three axes of the carrier coordinate system), and certain positioning accuracy can be maintained in the completely invalid observation of the satellite navigation system (such as a ground library scene).
Referring to fig. 4, the present application proposes a navigation method, including:
and 400, when the satellite navigation system is effectively observed, positioning the carrier according to data in a carrier coordinate system by adopting a close combination mode.
And 401, when the satellite navigation system fails to observe, positioning the carrier according to the data and the virtual observed quantity in the carrier coordinate system.
Specifically, when the carrier is in a static state, the virtual observation is constructed by complete constraint of which the three-axis speeds are all 0;
when the carrier is in a straight-going state or a turning state, the virtual observation quantity is constructed by using an incomplete constraint that the transverse speed (namely the right-direction speed of the carrier coordinate system) and the longitudinal speed (namely the downward speed of the carrier coordinate system) are 0.
According to the method and the device, when the observation of the satellite navigation system fails, the virtual observed quantity is constructed to replace the observed quantity of the satellite navigation system to position the carrier, so that the rapid accumulation of the navigation state errors during the operation of the inertial navigation system is effectively inhibited.
Referring to fig. 5, the present application proposes a navigation device including:
the acquisition module is used for acquiring the installation angle of an inertial sensor in the inertial navigation system;
and the first navigation module is used for converting data under an inertial sensor coordinate system output by the inertial sensor into data under a carrier coordinate system according to the installation angle, and positioning the carrier according to the data under the carrier coordinate system.
Optionally, the obtaining module is specifically configured to:
determining the state of the carrier according to the data output by the inertial sensor;
when the carrier is in a static state, determining an initial value of an attitude angle of the carrier;
updating the attitude angle of the carrier according to the initial value of the attitude angle of the carrier;
and when the carrier is in a turning state, judging whether the error of the attitude angle output by the inertial navigation system is converged, and when the error of the attitude angle output by the inertial navigation system is converged, determining the installation angle of the inertial sensor according to the speed output by the satellite navigation system and the speed output by the combined navigation system.
The installation angle of the inertial sensor can be determined according to the speed output by the satellite navigation system and the speed output by the combined navigation system under the condition of good satellite signal quality.
Optionally, the obtaining module is specifically configured to determine the state of the carrier according to the data output by the inertial sensor in the following manner:
when in use
Determining that the carrier is in a static state;
when in use
And is
Determining that the carrier is in a straight-moving state;
when in use
And is
Determining that the carrier is in a turning state;
wherein,
GA
ifor the ith data within a fixed time window, M
iIs the mean of the first i data, M
i-1Is the mean of the first (i-1) data, λ is the first threshold, D
iMean value of the difference of the first i data and the mean value, TD
iIs the average of the sum of squares of the first i angular velocity values,
is the sum of the squares of the ith set of angular velocity values and μ is the second threshold.
Optionally, the obtaining module is specifically configured to update the attitude angle of the carrier according to the initial value of the attitude angle of the carrier in the following manner:
calculating the first rotation matrix according to the initial value of the attitude angle;
converting data under an inertial sensor coordinate system output by the inertial sensor into data under a carrier coordinate system according to the first rotation matrix;
and updating the attitude angle of the carrier according to the data under the carrier coordinate system and the initial value of the attitude angle.
Optionally, the obtaining module is specifically configured to determine the first rotation matrix according to the speed output by the satellite navigation system and the speed output by the combined navigation system by using the following method:
determining a second rotation matrix according to the speed output by the satellite navigation system;
determining a third rotation matrix according to the speed output by the integrated navigation system;
and determining a first rotation matrix according to the second rotation matrix and the third rotation matrix.
Optionally, the obtaining module is specifically configured to determine the installation angle of the inertial sensor according to the first rotation matrix in the following manner:
according to the formula
Calculating a mounting roll angle;
according to the formula
Calculating an installation pitch angle;
according to the formula
Calculating an installation course angle;
wherein,
is the first rotation matrix.
Optionally, the first navigation module is specifically configured to:
converting data under an inertial sensor coordinate system output by the inertial sensor into data under a carrier coordinate system according to the installation angle;
when the satellite navigation system is effectively observed, positioning the carrier according to the data in the carrier coordinate system by adopting a close combination mode;
and when the satellite navigation system fails to observe, positioning the carrier according to the data and the virtual observed quantity in the carrier coordinate system.
Optionally, when the carrier is in a static state, the virtual observation is constructed by a complete constraint that the three-axis speeds are all 0;
when the carrier is in a straight-ahead state or a turning state, the virtual observations are constructed with an incomplete constraint of 0 for both lateral and longitudinal velocities.
The present application further provides a navigation device, including:
the second navigation module is used for positioning the carrier according to data in a carrier coordinate system by adopting a close combination mode when the satellite navigation system is effectively observed;
and when the satellite navigation system fails to observe, positioning the carrier according to the data and the virtual observed quantity in the carrier coordinate system.
The application provides a navigation device, which comprises a processor and a computer readable storage medium, wherein the computer readable storage medium stores instructions, and when the instructions are executed by the processor, any one of the navigation methods is realized.
The present application proposes a computer-readable storage medium having stored thereon a computer program which, when being executed by a processor, carries out the steps of any of the above-mentioned navigation methods.
Although the embodiments disclosed in the present application are described above, the descriptions are only for the convenience of understanding the present application, and are not intended to limit the present application. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims.