IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0166664
(2011-06-22)
|
등록번호 |
US-8594927
(2013-11-26)
|
우선권정보 |
FR-10 02675 (2010-06-25) |
발명자
/ 주소 |
- Louis, Christian
- Reynaud, Sébastien
|
출원인 / 주소 |
|
대리인 / 주소 |
|
인용정보 |
피인용 횟수 :
4 인용 특허 :
5 |
초록
▼
A navigation filter for a navigation system using terrain correlation delivering an estimation of the kinematic state of a carrier craft using a plurality of data includes the measurements returned by at least one terrain sensor, the model associated with the terrain sensor, the data from an onboard
A navigation filter for a navigation system using terrain correlation delivering an estimation of the kinematic state of a carrier craft using a plurality of data includes the measurements returned by at least one terrain sensor, the model associated with the terrain sensor, the data from an onboard map, an error model for the onboard map, the measurements returned by an inertial guidance system, and a model of the inertial guidance system. The navigation filter also includes a first filter referred to as convergence filter, for example of the Kalman filter type, and a second filter referred to as tracking filter, for example of the particle filter type.
대표청구항
▼
1. A navigation filter for a terrain aided navigation system, the navigation filter delivering an estimation of a kinematic state of a carrier craft associated with a covariance matrix at a discretized moment in time k, the navigation filter comprising: measurements returned by at least one terrain
1. A navigation filter for a terrain aided navigation system, the navigation filter delivering an estimation of a kinematic state of a carrier craft associated with a covariance matrix at a discretized moment in time k, the navigation filter comprising: measurements returned by at least one terrain sensor,a model associated with the at least one terrain sensor,data from an onboard map,an error model for the onboard map,measurements returned by an inertial guidance system,a model of the inertial guidance system,a convergence filter, anda tracking filter,the navigation filter further comprising switch-over means for selecting, for calculation of the estimation of the kinematic state of the carrier craft and of the covariance matrix, one or more of the convergence filter and the tracking filter, based on comparison of a quality index calculated from the covariance matrix at a preceding time k−1 with a predetermined threshold value, the navigation filter returning values calculated by the selected one or more of the convergence filter and the tracking filter. 2. The navigation filter according to claim 1, wherein the quality index is equal to a norm of terms of a sub-matrix of the covariance matrix. 3. The navigation filter according to claim 1, wherein the quality index is equal to a norm of terms of a sub-covariance matrix comprising position terms of the carrier craft in a horizontal plane. 4. The navigation filter according to claim 1, wherein the quality index is equal to a sum of squares of diagonal terms of a sub-covariance matrix comprising position terms of the carrier craft in a horizontal plane. 5. The navigation filter according to claim 1, wherein the convergence filter is of a particle filter type. 6. The navigation filter according to claim 1, wherein the convergence filter is of a marginalized particle filter type. 7. The navigation filter according to claim 1, wherein the tracking filter is of an extended Kalman filter EKF type. 8. The navigation filter according to claim 1, wherein the tracking filter is of a UKF type. 9. The navigation filter according to claim 1, wherein the tracking filter is associated with a device for rejection of outlier measurements from the navigation filter, the device rejecting the outlier measurements if a ratio between an innovation and a standard deviation of measurement noise exceeds a second predetermined threshold value. 10. The navigation filter according to claim 9, wherein the switch-over means comprise means for delivering, at an output of the navigation filter, data returned by said convergence filter when a number of consecutive measurements rejected by the device is greater than a third predetermined threshold value. 11. The navigation filter according to claim 1, further comprising: means for comparing a local standard deviation of the measurements returned by the at least one terrain sensor with a fourth predetermined threshold value, the estimation of the kinematic state of the carrier craft being based only on measurements supplied by a baro-altimeter within the inertial guidance system when the local standard deviation is less than the fourth predetermined threshold value.
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