KR101665375B1 - Navigation system and method - Google Patents

Abstract

This paper proposes a moving object navigation system and method, and a navigation filter. Specifically, the velocity vector and the heading are obtained through mathematical modeling which shows the physical correlation between the velocity vector and the heading angle among the initial navigation information derived from the inertial navigation system. A navigation filter for deriving a surplus value, which is an error of a predicted value derived from a virtual measured value and a partial differential value of a state variable of each navigation information, and correcting the initial navigation information by reflecting the derived surplus value on the initial navigation information As a result, robust and accurate navigation information can be derived without changing hardware and adding sensors.

Description

[0001] Moving object navigation system and method [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving object navigation system and method, and more particularly, to a system and method for performing navigation filtering without adding hardware and modifying navigation information derived from measured acceleration and angular velocity.

Inertial Navigation System (INS) is a system that derives navigation information (position, velocity, and attitude) using inertial sensors such as accelerometers and speedometers, and is used for mobile objects, automobiles, and hulls.

This inertial navigation system derives the navigation information by continuously integrating the measured values of the inertial sensor and has a peak that can provide highly accurate and continuous navigation information without being affected by the external environment.

However, there is a disadvantage in that errors in navigation information accumulate in a long travel section. To solve these shortcomings, a Global Position System (GNSS) has been proposed.

The satellite navigation system measures a distance (pseudo range) from at least four satellites among a plurality of satellites traveling around the earth to obtain a user's three-dimensional position and speed.

Such a satellite navigation system does not accumulate errors with respect to navigation information over time, but when the jamming of other radio waves is severe, or when the number of visible satellites is not more than four, .

In order to compensate for the disadvantages of the inertial navigation system and the satellite navigation system, a combined navigation system has recently been proposed. In addition to the satellite navigation system, additional sensors such as geomachinery and altimeter are introduced to compensate for errors in the inertial navigation system.

The existing combined navigation system is focused on adding external sensor information or improving the performance of the navigation filter and has a limitation in not connecting the physically related speed and attitude with a mathematical model.

Therefore, a separate navigation filter was needed to obtain robust and accurate navigation information without adding or modifying hardware.

An object of the present invention which is devised to solve the above problems is to derive a virtual measurement value through a mathematical model indicating a physical relation to a velocity vector and a heading angle with respect to initial navigation information derived from actually measured acceleration and angular velocity, When the magnitude of the speed information of the navigation information is equal to or greater than a predetermined threshold value, the navigation information is outputted based on the predicted value derived from the virtual measurement value and the state variable of the initial navigation information to output the corrected navigation information, And to provide a navigation system and method and a navigation filter capable of obtaining robust and accurate navigation information without adding a sensor.

According to an aspect of the present invention, there is provided a moving object navigation system including:

A navigation information deriving unit for deriving initial navigation information including position, speed and attitude information based on an acceleration and an angular velocity of a moving object supplied from an acceleration sensor and an angular velocity sensor,

A virtual measurement value derivation unit for deriving a virtual measurement value through mathematical modeling showing a physical relation between a velocity vector of the initial navigation information and a heading angle;

When the magnitude of the velocity information is greater than or equal to a predetermined threshold value, performing navigation filtering based on a virtual measurement value of the virtual measurement value deriving unit and a predictive value derived from linear observation modeling of state variables of each navigation information, And a navigation filter unit.

Here, the navigation filter unit includes:

And when the magnitude of the velocity information is not equal to or greater than the predetermined threshold, performing navigation filtering based on the predicted value derived from the linear observation modeling of the state variable of each navigation information, and outputting the corrected navigation information.

Wherein the virtual measurement value derivation unit comprises:

)은 남북 방향의 속도 성분과 동서 방향의 속도 성분의 비가 이루는 각과 헤딩각의 오차인 것이 바람직하다.The virtual measurement value is derived based on the physical relation between the velocity vector of the navigation information and the heading angle, and the derived virtual measurement value

) Is preferably an error of an angle and a heading angle formed by the ratio between the north-south direction speed component and the east-west direction speed component.

The navigation filter unit includes:

)을 도출하는 가상 측정값 예측 모듈과,The state variable of the navigation information on the position, velocity, and posture is partially differentiated to obtain a predicted value ("

A virtual measurement value prediction module for deriving a virtual measurement value,

)과 상기 가상 측정값(

)의 오차인 잉여치를 도출하는 잉여치 도출 모듈과,The predicted value (

) And the virtual measurement value (

), A surplus value derivation module for deriving a surplus value,

And a navigation information output module for outputting the corrected navigation information by correcting the initial navigation information by reflecting the surplus value to the initial navigation information derived by the navigation information deriving unit.

)은 Here, the predicted value (

)silver

It is preferable to derive the partial differential value for the state variable of the position, speed, and attitude information of the navigation information, and set the partial differential value for the calculated position information to 0, respectively.

The surplus value

)과 상기 가상 측정값(

)의 차로 도출되는 것이 바람직하다.The predicted value (

) And the virtual measurement value (

). ≪ / RTI >

According to an aspect of the present invention, there is provided a navigation filter of a moving object navigation system,

)를 생성하는 가상 측정값 예측 모듈과,The linear observation modeling is derived by partially differentiating each state variable of the navigation information including the position, velocity, and attitude of the moving object,

A virtual measurement value prediction module for generating a virtual measurement value,

)과 각 항법 정보에 대한 속도 벡터와 헤딩각의 물리적 연관성을 나타내는 수학적 모델링을 통해 도출된 가상 측정값(

) 간의 오차인 잉여치를 도출하는 잉여치 도출 모듈과,The predicted value (

) And the virtual measurement values derived from the mathematical modeling showing the physical association of the heading angle with the velocity vector for each navigation information

), A surplus value deriving module for deriving a surplus value,

And a navigation information output module for outputting the corrected navigation information by reflecting the surplus value to the inputted navigation information.

According to an aspect of the present invention,

A navigation information deriving step of deriving initial navigation information including position, speed and attitude information based on an acceleration and an angular velocity of a moving object supplied from an acceleration sensor and an angular velocity sensor

A virtual measurement value derivation step of deriving a virtual measurement value through mathematical modeling showing a physical relation between a velocity vector of the initial navigation information and a heading angle;

A navigation filter for performing navigation filtering based on the predicted values derived from the linear observation modeling of the virtual measurement values and the state variables of the respective navigation information when the magnitude of the velocity information of the navigation information is equal to or greater than a predetermined threshold, The method comprising the steps of:

In this case,

When the magnitude of the speed information of the navigation information is not equal to or greater than the predetermined threshold, it is preferable to perform the navigation filtering based on the predicted value derived from the linear observation modeling of the state variable of each navigation information to output the corrected navigation information.

Here, the virtual measurement value deriving step may include:

Deriving a virtual measurement value based on a physical association between the velocity vector of the navigation information and the heading angle,

)은 남북 방향의 속도 성분과 동서 방향의 속도 성분의 비가 이루는 각과 헤딩각의 오차인 것이 바람직하다.Derived virtual measurement (

) Is preferably an error of an angle and a heading angle formed by the ratio between the north-south direction speed component and the east-west direction speed component.

The navigation filter step comprises:

)을 도출하고,The state variables of the navigation information on the position, velocity, and attitude are partially differentiated and linear predictive modeling

≪ / RTI >

)과 가상 측정값(

)의 오차인 잉여치를 도출하며,The predicted value and (

) And the virtual measurement value

), Which is an error of the error,

It is preferable that the initial navigation information is corrected by reflecting the surplus value and then the corrected navigation information is outputted.

)은 The predicted value (

)silver

It is preferable to derive the partial differential value for each of the state variables of the position, velocity, and attitude information of the navigation information, and then set the partial differential value for the calculated position information to zero.

The surplus value

)과 상기 가상 측정값(

)의 차로 도출되는 것이 바람직하다.
The predicted value (

) And the virtual measurement value (

). ≪ / RTI >

As described above, according to the navigation system and method and the navigation filter according to the present invention, mathematical modeling showing the physical relevance of the velocity vector and the heading angle to the initial navigation information derived from the measured acceleration and angular velocity The virtual measurement value is derived, and when the velocity magnitude of the navigation information is equal to or greater than a predetermined threshold value, the navigation filter is executed based on the virtual measurement value and the predicted value derived from the partial derivative of the state variable of each navigation information to output the corrected navigation information Therefore, the navigation filtering is performed through the physical association between the velocity vector and the heading value, so that robust and accurate navigation information can be obtained without additional hardware modification and sensor addition.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description of the invention given below, serve to further understand the technical idea of the invention. And should not be construed as limiting.
1 is a diagram illustrating a configuration of a moving object navigation system according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a configuration of a navigation filter unit of a moving object navigation system according to an embodiment of the present invention.
3 is a flowchart illustrating an operation procedure of a mobile object navigation system according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the following drawings, like reference numerals are used to denote like elements, and the same reference numerals are given to the same elements even if they are shown in different drawings, Detailed description of functions and configurations is omitted.

FIG. 1 is a diagram illustrating a configuration of a moving object navigation system according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating the configuration of a navigation filter unit of the moving object navigation system shown in FIG.

1 and 2, a moving object navigation system according to an embodiment of the present invention includes a navigation information derivation unit 10, a virtual measurement value derivation unit 30, a virtual measurement value output unit 50, And a filter unit 70.

The navigation information derivation unit 10 includes an acceleration coordinate conversion module 12 for converting an acceleration measurement value supplied from the acceleration sensor 11 into an acceleration coordinate system and an angular velocity measurement unit 12 for calculating an angular velocity measurement value supplied from the angular velocity sensor 13 And an attitude information derivation module 14 for deriving attitude information based on the attitude information and providing it to the acceleration coordinate transformation module 12. [

The navigation information derivation unit 10 includes a correction module 15 that continuously corrects the gravitational acceleration and the Coriolis effect reflected in the acceleration measurement value, and then derives the corrected acceleration information.

The navigation information derivation unit 10 further includes an initial navigation filter module 16 for deriving initial navigation information including velocity, position, and attitude information of a moving object based on acceleration information and angular velocity information of the correction module 15 .

Here, the initial navigation information of the navigation filter module 16, which is derived based on the acceleration information and the angular velocity information corrected for the gravitational acceleration and the Coriolis effect, satisfies the following expression (11).

… 식 11

... Equation 11

은 위치,

은 속도,

은 자세,

는 방향코사인 행렬(동체좌표계에서 항법좌표계로 변환),

는 회전각속도변환행렬,

는 동체좌표계의 비력가속도,

는 중력가속도,

는 각속도, 첨자는 좌표계이고, n은 항법좌표계, b는 동체좌표계이다.here,

The location,

The speed,

Silver posture,

Is a direction cosine matrix (conversion from the body coordinate system to the navigation coordinate system),

A rotational angular velocity conversion matrix,

Is the gravitational acceleration of the body coordinate system,

Gravity acceleration,

Is the angular velocity, subscript is the coordinate system, n is the navigation coordinate system, and b is the fuselage coordinate system.

When the nonlinear estimation algorithm is used, the navigation filter module 16 does not need to linearize the initial navigation information. However, when deriving the error information of the initial navigation information using a linear estimation algorithm such as a Kalman filter, A linearized model of navigation information is needed.

Therefore, the error information for the initial navigation information derived through the linearized model satisfies the following expression (12). Where w ⁿ is the angular velocity derived through the linearization model.

… 식 12

... Equation 12

The navigation filter module 16 outputs initial navigation information in which the error information is corrected.

In the embodiment of the present invention, the process of outputting the initial navigation information of the navigation information deriving unit 10 is similar to or the same as the process of deriving the navigation information in the conventional inertial navigation system or the combined inertial system, The description is omitted.

In addition, the initial navigation information of the navigation information derivation unit 10 is transmitted to the virtual measurement value derivation unit 30

The virtual measurement value derivation unit 30 is configured to derive a virtual measurement value reflecting the association of the velocity and the heading angle among the initial navigation information including the provided velocity, position, and attitude information.

That is, the traveling moving body has a heading angle and a yaw angle with respect to the traveling direction, and the heading angle and the yaw angle cause an error in SLIP of the moving object. However, the error between the heading angle and the yaw angle is temporarily generated at the time of rotation or is relatively small compared to the total heading angle. Therefore, the yaw angle in the embodiment of the present invention is defined as having the same value as the heading angle.

The heading, which is the azimuth angle of the velocity vector projected on the horizontal plane, is expressed by the inverse tangent (tan ^-1 ) of the velocity component (Vn) in the north-south direction and the velocity component (Ve) 13.

… 식 13

... Equation 13

In this case, the heading is a component calculated in the rotational equation of motion, and the velocity component is a component calculated in the translational equation of motion. Therefore, the attitude information including the heading angle affects the velocity calculation, Not used. That is, the attitude information is transmitted to the translational motion (position and velocity information), but the velocity information is not transmitted to the rotational motion (attitude information).

Therefore, based on the characteristics between the speed information and the attitude information, a virtual measurement value z, which is an error between the speed information and the attitude information, is generated.

… 식 14

... Equation 14

Meanwhile, the virtual measurement value output unit 50 compares the magnitude of the velocity information among the initial navigation information with a predetermined threshold, and when the magnitude of the comparison result velocity information is greater than or equal to the threshold value, (70).

)을 도출하는 가상 측정값 예측 모듈(71)과, 상기 예측값(

)과 상기 가상 측정값(

)의 오차인 잉여치를 도출하는 잉여치 도출 모듈(73)과, 상기 잉여치를 상기 항법 정보 도출부에서 도출된 항법 정보에 반영하여 상기 초기 항법 정보를 보정한 후 보정된 항법 정보를 출력하는 항법 정보 출력 모듈(75)의 구성을 갖춘다.The navigation filter unit 70 partially differentiates the state variables of the initial navigation information with respect to the position, velocity, and attitude, and calculates a predicted value

A virtual measurement value prediction module 71 for deriving a predicted value

) And the virtual measurement value (

The navigation information deriving module calculates the initial value of the navigation information based on the navigation information derived from the navigation information deriving part and outputs the corrected navigation information, And an output module 75.

)은 상기 초기 항법 정보의 위치, 속도, 및 자세에 대한 상태 변수로부터 도출되며, 다음 식 15를 만족하는 것이 바람직하다.Here, the predicted value of the virtual measurement value prediction module 71

) Is derived from the state variables for the position, speed, and attitude of the initial navigation information, and preferably satisfies the following expression (15).

…. 식 15

... . Equation 15

은 위치,

은 속도,

는 자세,

은 항법 좌표계를 나타내고, 상기 예측값(

)는 위치 함수가 아니므로, 위치 정보에 대한 편미분(

) 값은 0 이 된다.here,

The location,

The speed,

The posture,

Represents the navigation coordinate system, and the predicted value (

) Is not a position function, the partial differential (

) Value is zero.

)과 상기 가상 측정값(

)의 오차인 잉여치를 도출하며, 상기 가상 측정값(

)는 초기 항법 정보의 각 상태 변수에 대한 관계식으로 정의되는 바, 물리적인 상관성을 나타내는 헤딩각과 속도 벡터의 사이각은 동일한 값이므로, 가상 측정값(

)은 0이 된다. Further, the surplus value derivation module 73 calculates the surplus value

) And the virtual measurement value (

), And the virtual measurement value (

) Is defined as a relational expression for each state variable of the initial navigation information. Since the angle between the heading angle representing the physical correlation and the velocity vector is the same value, the virtual measurement value

) Becomes zero.

)과 상기 가상 측정값(

)의 차로 도출되며, 다음 식 16을 만족한다.Therefore, the surplus value is the predicted value (

) And the virtual measurement value (

), And satisfies the following expression (16).

… 식 16

... Equation 16

Then, the navigation information output module 75 corrects the initial navigation information by reflecting the surplus value, and outputs corrected navigation information (position, speed, and attitude information).

Therefore, a surplus value, which is an error between a virtual measurement value representing a physical correlation between a velocity vector and a heading angle and a predicted value derived by a partial derivative value of a state variable of each navigation information, is derived from initial navigation information derived from a conventional inertial navigation system And the derived surplus value is reflected on the initial navigation information to correct the initial navigation information and output the navigation information. Thus, it is possible to obtain robust and accurate navigation information without changing the hardware and adding a sensor.

In the embodiment of the present invention, the surplus value, which is the error between the estimated value derived from the virtual measured value and the partial differential value of the state variable of each navigation information, which is the angle between the velocity vector of the initial navigation information derived from the inertial navigation system and the heading angle, Although a process of deriving robust navigation information has been described as an example, it will be apparent to those skilled in the art that the present invention can also be applied to a combined navigation system.

The derived initial navigation information based on the virtual measured value which is the angle between the velocity vector of the initial navigation information derived from the inertial navigation system and the heading angle and the residual value which is the error of the predicted value derived from the partial differential value of the state variable of each navigation information A series of processes of correcting and obtaining robust navigation information will be described with reference to FIG.

FIG. 3 is a flowchart illustrating an operation procedure of the mobile object navigation system shown in FIG. 1. Referring to FIGS. 1 and 3, the operation procedure of the mobile object navigation system according to another embodiment of the present invention will be described.

First, the navigation information deriving unit 10 derives initial navigation information including position, speed, and attitude information based on the acceleration and the angular velocity of the moving object supplied from the acceleration sensor and the angular velocity sensor through step 101.

Meanwhile, the virtual measurement value derivation unit 30 derives a virtual measurement value that is an angle between the magnitude of the velocity vector and the heading angle through mathematical modeling indicating the physical relation between the velocity vector and the heading angle in the initial navigation information (step 103 ).

The virtual measurement value output unit 50 compares the size of the speed information among the navigation information with a predetermined threshold value and outputs a virtual measurement value to the navigation filter unit 50 when the size of the speed information is equal to or greater than the threshold value, 70 (steps 105 and 107).

 The navigation filter unit 70 derives predicted values from linear observation modeling of state variables of each navigation information, derives surplus values based on the derived predicted values and virtual measurement values, and calculates the initial navigation information by reflecting the derived surplus values. After correction, the corrected navigation filter is output (steps 109, 111, 113)

According to the present invention, among the initial navigation information derived from the inertial navigation system, a virtual measurement value representing a physical correlation between the velocity vector and the heading angle and a surplus value, which is an error of the predicted value derived from the partial derivative value of the state variable of each navigation information, And the navigation information to output the navigation information after correcting the initial navigation information by reflecting the surplus value derived from the initial navigation information to the initial navigation information, thereby robust and accurate navigation information can be derived without changing the hardware and adding the sensor .

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied in the form of a program form which may be performed via a variety of computing means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, 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 invention as defined by the appended claims.

In the initial navigation information derived from a conventional inertial navigation system, a virtual measurement value representing a physical correlation between a velocity vector and a heading angle and a surplus value, which is an error of a predicted value derived from a partial derivative value of a state variable of each navigation information, A moving object navigation system and method for deriving robust and accurate navigation information without changing the hardware and adding a sensor by performing the navigation filtering for correcting the initial navigation information by reflecting surplus values in the initial navigation information, It is possible to make a great progress in terms of accuracy and reliability of operation and further in terms of performance efficiency and it is possible that the applicable mobile navigation system is not only commercially available, Invention.

Claims (14)

A navigation information deriving unit for deriving initial navigation information including position, speed and attitude information based on an acceleration and an angular velocity of a moving object supplied from an acceleration sensor and an angular velocity sensor,
A virtual measurement value derivation unit for deriving a virtual measurement value through mathematical modeling showing a physical relation between a velocity vector of the initial navigation information and a heading angle;
When the magnitude of the velocity information is greater than or equal to a predetermined threshold value, performing navigation filtering based on a virtual measurement value of the virtual measurement value deriving unit and a predictive value derived from linear observation modeling of state variables of each navigation information, And a navigation filter unit. The navigation device according to claim 1,
And when the magnitude of the velocity information is not equal to or greater than a predetermined threshold value, performing navigation filtering based on a predictive value derived from linear observation modeling of state variables of each navigation information to output corrected navigation information. system. 3. The apparatus of claim 2,
Deriving a virtual measurement value based on a physical association between the velocity vector of the navigation information and the heading angle,
Derived virtual measurement (

) Is an error of an angle and a heading angle formed by the ratio of the velocity component in the north-south direction and the velocity component in the east-west direction. The navigation device according to claim 3,
The state variable of the navigation information on the position, velocity, and posture is partially differentiated to obtain a predicted value ("

A virtual measurement value prediction module for deriving a virtual measurement value,
The predicted value (

) And the virtual measurement value (

), A surplus value derivation module for deriving a surplus value,
And a navigation information output module for outputting the corrected navigation information by correcting the initial navigation information by reflecting the surplus value in the initial navigation information derived by the navigation information deriving unit. 5. The method according to claim 4,

)silver
And calculating partial differential values for the state variables of the position, speed, and attitude information of the navigation information, and setting the partial differential value for the calculated position information to zero. 6. The method of claim 5, wherein the surplus value
The predicted value (

) And the virtual measurement value (

) Of the moving object. The linear observation modeling is derived by partially differentiating each state variable of the navigation information including the position, velocity, and attitude of the moving object,

A virtual measurement value prediction module for generating a virtual measurement value,
The predicted value (

) And the virtual measurement values derived from the mathematical modeling showing the physical association of the heading angle with the velocity vector for each navigation information

), A surplus value deriving module for deriving a surplus value,
And a navigation information output module for outputting the corrected navigation information by reflecting the surplus value to the inputted navigation information.
A navigation information deriving step of deriving initial navigation information including position, speed and attitude information based on an acceleration and an angular velocity of a moving object supplied from an acceleration sensor and an angular velocity sensor
A virtual measurement value derivation step of deriving a virtual measurement value through mathematical modeling showing a physical relation between a velocity vector of the initial navigation information and a heading angle;
A navigation filter for performing navigation filtering based on the predicted values derived from the linear observation modeling of the virtual measurement values and the state variables of the respective navigation information when the magnitude of the velocity information of the navigation information is equal to or greater than a predetermined threshold, Wherein the moving object is a moving object. 9. The method of claim 8,
And when the magnitude of the velocity information of the navigation information is not equal to or greater than a predetermined threshold, the navigation device performs the navigation filtering based on the predicted value derived from the linear observation modeling of the state variable of each navigation information to output the corrected navigation information. Navigation method. 10. The method according to claim 9,
Deriving a virtual measurement value based on a physical association between the velocity vector of the navigation information and the heading angle,
Derived virtual measurement (

) Is an error of an angle and a heading angle formed by the ratio of the velocity component in the north-south direction and the velocity component in the east-west direction. 11. The method of claim 10,
The state variables of the navigation information on the position, velocity, and attitude are partially differentiated and linear predictive modeling

≪ / RTI >
The predicted value and (

) And the virtual measurement value

), Which is an error of the error,
And to output the corrected navigation information after correcting the initial navigation information by reflecting the surplus value. 12. The method according to claim 11,

)silver
And calculating partial differential values for the state variables of the position, speed, and attitude information of the navigation information, and setting the partial differential value for the calculated position information to zero. 13. The method of claim 12, wherein the surplus value
The predicted value (

) And the virtual measurement value (

) Of the moving object. 14. A computer-readable medium comprising instructions for performing each step of the method according to any one of claims 8-13.

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