KR101644263B1 - Method and Device for Estimating position of Vehicle - Google Patents

Abstract

A vehicle position estimation method and apparatus capable of reducing the calculation load due to coordinate transformation are disclosed. The disclosed vehicle position estimation method includes: generating inertial navigation position information of a vehicle defined in a first coordinate system using a vehicle sensor; Using the GPS device, generating first GPS position information of the vehicle defined in the second coordinate system; Updating the first GPS position information with the second GPS position information using the position conversion value and the inertial navigation position information; And generating the position conversion value using the second GPS position information.

Description

Technical Field [0001] The present invention relates to a method and an apparatus for estimating a vehicle position,

The present invention relates to a vehicle position estimation method and apparatus, and more particularly, to a vehicle position estimation method and apparatus using position information defined in different coordinate systems.

As a GPS (Global Positioning System) receiver has been developed, a GPS device is used as a position sensor in a commercial vehicle navigation system. Also, a location based service (LBS) such as a route guidance service and a location based information providing service is provided using the location information of the vehicle obtained through the GPS device. Furthermore, location-based control using GPS is also being performed on military vehicles and guided weapons. However, there is a case where the GPS device can not completely or partially receive the GPS satellite signal in the tunnel, the underground parking lot, the urban area, and the mountainous area, so that there is a problem in that continuous positional information can not be provided when the GPS device is used .

Therefore, in order to provide continuous position information irrespective of the place, an INS / GPS system combining an inertial navigation system (INS) using a vehicle sensor such as an inertial sensor (for example, an accelerometer and a gyroscope) A GPS navigation system has been proposed. Since the position information by the inertial navigation device and the position information by the GPS device are defined in different coordinate systems, coordinate conversion process is required when fusing the inertial navigation position information and the GPS position information.

FIG. 1 is a diagram for explaining a conventional coordinate transformation process.

In general, the coordinate system used in GPS is a geodetic coordinate system, and the coordinate system used in the inertial navigation system is the Northeast (ENU) coordinate system. Therefore, when the inertial navigation position information according to the vehicle motion is fused to the GPS information and the final position information according to the geodetic coordinate system is generated, the inertial navigation position information defined in the northeast coordinate system is used as the position information according to the geodetic coordinate system Should be converted. That is, after converting the coordinate value according to the northeast coordinate system to the coordinate value according to the geodesic coordinate system, the transformed coordinate value is reflected in the GPS information to estimate the final position.

Bayesian filters are generally used for coordinate transformation and fusion. When a Bayesian filter is defined as a Northeast coordinate system, as shown in FIG. 1 (a), GSP location information is converted into position information according to the Northeast coordinate system, After calculating the position, it should be converted into the position information according to the geodesic coordinate system.

If the Bayesian filter is defined as a geodesic coordinate system as shown in FIG. 1 (b), the final position should be calculated by converting the inertial navigation position information into positional information according to the geodesic coordinate system. Although not shown in the drawing, when generating the final position information according to the Northeast coordinate system, it is also necessary to convert all the coordinate values according to the geodesic coordinate system.

In the case of a vehicle moving at high speed, when the position estimation is delayed according to the coordinate transformation operation process, the position error of the vehicle may be increased, so it is necessary to study the vehicle position estimation method which reduces the calculation amount and reduces the load Do.

The present invention is to provide a vehicle position estimation method and apparatus capable of reducing a calculation load in accordance with coordinate transformation.

According to an aspect of the present invention, there is provided a method of estimating inertial navigation position of a vehicle, the method comprising: generating inertial navigation position information of a vehicle defined in a first coordinate system using a vehicle sensor; Using the GPS device, generating first GPS position information of the vehicle defined in the second coordinate system; Updating the first GPS position information with the second GPS position information using the position conversion value and the inertial navigation position information; And generating the position conversion value using the second GPS position information.

According to another aspect of the present invention, there is provided a method of estimating inertial navigation position of a vehicle, the method comprising: generating inertial navigation position information of a vehicle defined in a first coordinate system using a vehicle sensor; Using the GPS device, generating GPS position information of the vehicle defined in the second coordinate system; Determining a position conversion value using the latitude information and the altitude information in the GPS position information; And updating the GPS position information using the position conversion value and the inertial navigation position information.

According to another aspect of the present invention, there is provided a vehicle navigation system comprising: a first position information generation unit for generating inertia navigation position information of a vehicle defined in a first coordinate system using a vehicle sensor; A second position information generation unit for generating first GPS position information of the vehicle defined in a second coordinate system; A position information updating unit updating the first GPS position information with the second GPS position information using the position conversion value and the inertial navigation position information; And a position conversion value generator for generating the position conversion value using the second GPS position information.

According to the present invention, the position of the vehicle can be accurately estimated without the calculation load by reflecting the inertial navigation position information to the GPS position information using the position conversion value determined according to the GPS position information.

Further, according to the present invention, it is possible to improve the accuracy of the vehicle position estimation by generating and using the position conversion value by feeding back the updated GPS information.

FIG. 1 is a diagram for explaining a conventional coordinate transformation process.
2 is a view for explaining a vehicle position estimation apparatus according to an embodiment of the present invention.
3 is a view for explaining a vehicle position estimation apparatus according to a specific embodiment of the present invention.
4 is a diagram for explaining vehicle position estimation results according to the present invention.
5 is a view for explaining a vehicle position estimation method according to an embodiment of the present invention.
6 is a view for explaining a vehicle position estimation method according to another embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

The present invention relates to a method and an apparatus for estimating a vehicle position by efficiently integrating GPS position information and inertial navigation position information defined in different coordinate systems. More particularly, the present invention relates to a method and apparatus for converting an inertial navigation position information defined in a first coordinate system into GPS position information defined in a second coordinate system, By reflecting the position information to the GPS position information, the position of the vehicle can be accurately estimated without a calculation load. Further, the present invention can improve the accuracy of the vehicle position estimation by generating and using the position conversion value by feeding back the updated GPS information.

Hereinafter, a position estimation method for a vehicle will be described as an embodiment. However, the present invention can be applied to all vehicles such as an aircraft, a ship, and the like that use inertial navigation position information and GPS position information as in a vehicle.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a view for explaining a vehicle position estimation apparatus according to an embodiment of the present invention.

2, the vehicle position estimation apparatus according to the present invention includes a first position information generation unit 210, a second position information generation unit 220, a position information update unit 230, (240).

The first position information generator 210 generates the inertial navigation position information of the vehicle defined in the first coordinate system using the vehicle sensor. The second position information generation unit 220 generates the first GPS position information of the vehicle defined by the two-coordinate system.

That is, each of the first and second position information generators 210 and 220 generates position information of a vehicle defined by different coordinate systems. For example, the first coordinate system may be a Northeast coordinate system as a plane coordinate system, The second coordinate system may be a geodesic coordinate system. The northeast coordinate system is composed of east coordinate, north coordinate and up coordinate, and the geodesic coordinate system is composed of longitude coordinates, latitude coordinates and altitude coordinates. The second location information generation unit 220 may be a GPS device.

The position information update unit 230 updates the first GPS position information with the second GPS position information using the position conversion value and the inertial navigation position information. That is, the position information update unit 230 reflects the inertial navigation position information to the first GPS position information using the position conversion value, and generates the second GPS position information updated from the first GPS position information.

In this case, the position conversion value is a value determined according to the GPS position information, and the position conversion value generation unit 240 can generate the position conversion value using the first GPS position information or the second GPS position information. Since the second GPS position information is the updated latest position information, the accuracy of the second GPS position information can be further improved when the second GPS position information is used.

As is well known, the Earth is not a perfect sphere, so the radius of the Earth's ellipsoid (radius of curvature) varies with latitude. And depending on the altitude at which the vehicle is located, the radius of the earth's ellipsoid varies. Therefore, in order to accurately reflect the position information in the Northeast coordinate system presuming the plane position to the GPS position information based on the earth ellipsoid, the present invention uses the position conversion value determined according to the GPS position information, To the GPS position information.

In one embodiment, the position conversion value may be a value determined according to the latitude information and the altitude information in the second GPS position information. The position conversion value may be an approximated constant value determined according to the latitude information and the altitude information. Accordingly, according to the present invention, the inertial navigation position information can be reflected in the GPS position information without complicated formula for coordinate conversion.

3 is a view for explaining a vehicle position estimation apparatus according to a specific embodiment of the present invention.

3, the vehicle position estimation apparatus 300 according to the present invention includes a position estimation unit 310 and a position correction unit 320. Vehicle sensor 330 and GPS device 340 may be provided in the vehicle.

The vehicle sensor 330 may be, for example, an acceleration sensor, a wheel speed sensor, or the like, and the position estimating unit 310 may generate the inertial navigation position information of the vehicle using the sensed value of the vehicle sensor 330 .

The position correcting unit 320 can use a Bayesian filter and updates the first GPS position information generated by the GPS device 340 with the second GPS position information. At this time, the position correcting unit 320 updates the first GPS position information using the position conversion value and the inertial navigation position information. The position conversion value is generated by the position estimation unit 310. The position estimation unit 310 receives the second GPS position information from the position correction unit 320 and generates a position conversion value.

) 및 고도 정보(

)를 이용하여 위치 변환값을 생성할 수 있으며, 일실시예로서 [수학식 1] 및 [수학식 2]를 이용하여 위치 변환 값(

,

)을 생성할 수 있다. GPS 정보가 갱신되는 주기가 매우 짧을 경우 차량의 위치 변화량이 크지 않기 때문에, [수학식 1] 및 [수학식 2]과 같이 근사화된 위치 변화값을 이용하여 관성 항법 위치 정보를 GPS 위치 정보에 반영할 수 있다. 또한 후술되지만 제1위치 변화값(

)은 경도 정보의 갱신에 이용되기 때문에, 횡 곡률반경을 이용하고, 제2위치 변화값(

)은 위도 정보의 갱신에 이용되기 때문에 자오선 곡률반경이 이용된다.The location estimating unit 320 estimates the latitude of the second GPS location information

) And altitude information (

), And the position conversion value may be generated using the position conversion value ((1), (2), and

,

Can be generated. Since the vehicle position change amount is not large when the GPS information update period is very short, inertial navigation position information is reflected in the GPS position information using approximated position change values as shown in [Equation 1] and [Equation 2] can do. Also, as will be described later,

) Is used for updating the hardness information, the lateral radius of curvature is used and the second position change value (

) Is used to update the latitude information, the meridional radius of curvature is used.

는 지구타원체상 임의 지점에서 동서방향의 곡률반경, 즉 횡 곡률반경(normal radius)를 나타내며,

는 지구타원체상 임의 점에서 남북방향의 곡률반경, 즉 자오선 곡률반경(meridian radius)를 나타낸다. here,

Represents the radius of curvature in the east-west direction, that is, the normal radius at any point on the earth's ellipsoid,

Represents the radius of curvature in the north-south direction at any point on the earth's ellipsoid, that is, the meridian radius.

,

)를 제2GPS 위치 정보(

,

)로 갱신할 수 있다. 위치 변화값은 상수값이기 때문에, 위치 보정부(320)는 연산 부하없이 관성 항법 위치 정보를 GPS 위치 정보에 반영할 수 있다.Then, the position correcting unit 320 corrects the first GPS position information (

,

) To the second GPS position information (

,

). ≪ / RTI > Since the position change value is a constant value, the position correcting unit 320 can reflect the inertial navigation position information in the GPS position information without an operation load.

는 경도 정보를 나타내며,

및

각각은 기 설정된 측정 구간에서의 관성 항법 위치 정보 중 이스트 좌표의 변화량 및 노스 좌표의 변화량을 나타낸다.here,

Represents hardness information,

And

Each represents the amount of change of the east coordinate and the amount of change of the north coordinate in the inertial navigation position information in the predetermined measurement interval.

Meanwhile, as described above, the position correcting unit 320 updates the first GPS position information using the position conversion value and the variation amount of the inertial navigation position information in the predetermined measurement interval, because the vehicle continues to move in the measurement interval Not only the inertial navigation position information but also the GPS information changes. Therefore, the position correcting unit 320 reflects the first GPS position information in the measurement interval, and generates the second GPS position information from the updated first GPS position information.

More specifically, the position correcting unit 320 reflects the amount of change of the inertial navigation position information, as shown in Equation (4), and calculates the amount of change of the east coordinate in the measurement interval between k-th to k- The latitude information and the latitude information of the first GPS position information are updated. The altitude information of the first GPS position information is updated using the vertical velocity information and the time variation amount of the vehicle generated from the GPS device 340.

Then, the position correcting unit 320 generates the final second GPS position information by reflecting the first GPS position information updated by Equation (4) and the GPS position information in the measuring period as in Equation (5) can do.

Here, H is a constant determined according to a coordinate system, which may be 1, and k is a constant that can be variously determined depending on the system. And the subscript GPS indicates the GPS position information measured at the (k + 1) th position.

On the other hand, the accuracy of the GPS position information can be measured through the variance value of the GPS position information, and the variance value can be expressed as Equation (6).

는 [수학식 4]에 의해 얻어진 GPS 위치 정보에 대한 분산값이며,

는 [수학식 5]에 의해 얻어진 GPS 위치 정보에 대한 분산값이다. 일반적으로 분산값을 획득하기 위해서는 편미분이 필요한데, 본 발명에 따른 위치 변환값(

,

)은 상수값이므로 용이하게 분산값이 획득될 수 있다.
here,

Is the variance value for the GPS position information obtained by the equation (4)

Is a variance value for the GPS position information obtained by the equation (5). In general, a partial derivative is required to obtain a variance value. The position conversion value

,

) Is a constant value, a dispersion value can be easily obtained.

4 is a diagram for explaining vehicle position estimation results according to the present invention.

FIG. 4 is a graph comparing the result of vehicle position estimation according to the existing algorithm for estimating the position of the vehicle through the coordinate transformation and the vehicle position estimation result according to the present invention. The maximum error is 5 * 10 ^-8 m, .

Also, as a result of the comparison of the calculation speed, it was found that the calculation speed of the vehicle position estimation method according to the present invention is improved by 58.9% on the PC and 93.1% in the embedded environment.

That is, according to the present invention, it is possible to accurately estimate the position of the vehicle without a calculation load.

5 is a view for explaining a vehicle position estimation method according to an embodiment of the present invention.

The vehicle position estimation apparatus generates inertial navigation position information of the vehicle defined in the first coordinate system using the vehicle sensor (S510). Then, the first GPS position information of the vehicle defined by the second coordinate system is generated using the GPS device (S520). The first coordinate system may be a northeast coordinate system, and the second coordinate system may be a geodesic coordinate system.

The vehicle position estimation apparatus updates the first GPS position information to the second GPS position information using the position conversion value and inertial navigation position information (S530), and generates the position conversion value using the second GPS position information (S540) . Here, the position conversion value may be determined according to the latitude information and the altitude information in the second GPS position information, and may be a value determined according to the radius of curvature of the earth ellipsoid according to the latitude information.

More specifically, the vehicle position estimation apparatus updates the first GPS position information using the position conversion value and the amount of change of the inertial navigation position information in the predetermined measurement interval, reflects the first GPS position information in the measurement interval, And generate second GPS position information from the first GPS position information.

At this time, the vehicle position estimation apparatus updates the hardness information in the first GPS position information using the amount of change of the east coordinate in the inertial navigation position information, and uses the amount of change in the north coordinate in the inertial navigation position information, The latitude information can be updated. The altitude information of the first GPS position information can be updated by using the vertical velocity change amount of the vehicle.

6 is a view for explaining a vehicle position estimation method according to another embodiment of the present invention.

Compared with the vehicle position estimation method of FIG. 5, the vehicle position estimation method of FIG. 6 differs in the information used for generating the position conversion value.

More specifically, the vehicle position estimation apparatus generates inertial navigation position information of the vehicle defined in the first coordinate system using the vehicle sensor (S610), and uses the GPS device to calculate the GPS position information of the vehicle defined in the second coordinate system (S620).

Then, the vehicle position estimation apparatus determines the position conversion value using the latitude information and the altitude information in the GPS position information (S630), and updates the GPS position information using the position conversion value and the inertial navigation position information (S640). At this time, the position conversion value may be determined according to the latitude information and the altitude information in step S620, or may be determined according to the latitude information and the altitude information in step S640.

The above-described technical features may be implemented in the form of program instructions that can be executed through various computer 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 embodiments 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 device may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and specific embodiments and drawings. However, it should be understood that the present invention is not limited to the above- And various modifications and changes may be made thereto by those skilled in the art to which the present invention pertains. Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (10)

Generating inertial navigation position information of the vehicle defined in the first coordinate system using the vehicle sensor;
Using the GPS device, generating first GPS position information of the vehicle defined in the second coordinate system;
Updating the first GPS position information with the second GPS position information by reflecting a variation value of the inertial navigation position information and a multiplication value of the position conversion value; And
And generating the position conversion value using the second GPS position information,
The position conversion value
A first location conversion value that is determined according to latitude information and altitude information in the second GPS location information, and a radius of curvature in accordance with the latitude information; And
Determining a second position change value < RTI ID = 0.0 > (2) < / RTI > determined based on altitude information and the meridian radius of curvature in accordance with the latitude information,
And estimating the vehicle position.
delete delete The method according to claim 1,
The step of updating the first GPS position information with the second GPS position information
Updating the first GPS position information using the position conversion value and a change amount of the inertial navigation position information in a predetermined measurement interval; And
Generating the second GPS position information from the updated first GPS position information by reflecting the first GPS position information in the measurement period
And estimating the vehicle position.
5. The method of claim 4,
The step of updating the first GPS location information
Updating the hardness information in the first GPS position information using the amount of change of the east coordinate in the inertial navigation position information;
Updating the latitude information in the first GPS position information using the amount of change of the north coordinate in the inertial navigation position information; And
Updating the altitude information among the first GPS position information using the vertical velocity change amount of the vehicle
And estimating the vehicle position.
The method according to claim 1,
The first coordinate system is a northeast coordinate system,
The second coordinate system is a geodesic coordinate system
A method for estimating a vehicle position.
delete delete delete A first position information generation unit for generating inertia navigation position information of a vehicle defined by a first coordinate system using a vehicle sensor;
A second position information generation unit for generating first GPS position information of the vehicle defined in a second coordinate system;
A position information updating unit for updating the first GPS position information with the second GPS position information by reflecting a multiplication value of the inertial navigation position information and the position conversion value; And
And a position conversion value generator for generating the position conversion value using the second GPS position information,
The position conversion value
A first location conversion value that is determined according to latitude information and altitude information in the second GPS location information, and a radius of curvature in accordance with the latitude information; And
Determining a second position change value < RTI ID = 0.0 > (2) < / RTI > determined based on altitude information and the meridian radius of curvature in accordance with the latitude information,
The vehicle position estimating apparatus comprising:

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