Claims:WE CLAIM
1. A method for determining a drivable navigation path for an autonomous vehicle, the method comprising:
receiving, by a navigation device, a base navigation path on a navigation map, a position and an orientation of the autonomous vehicle with respect to the base navigation path, and an environmental field of view (FOV);
deriving, by the navigation device, a navigational FOV based on the environmental FOV, the base navigation path, and the orientation of the vehicle;
determining, by the navigation device, a set of navigational data points from the navigational FOV; and
generating, by the navigation device, at least a portion of the drivable navigation path for the autonomous vehicle based on the set of navigational data points.

2. The method of claim 1, wherein the base navigation path is received from a global positioning system (GPS) based navigation path service provider, wherein the position of the autonomous vehicle is received from a GPS sensor, wherein the orientation of the autonomous vehicle is received from an inertia measurement unit (IMU), and wherein the environmental FOV is received from a light detection and ranging (LIDAR) scanner.

3. The method of claim 1, wherein deriving the navigational FOV comprises determining an approachable volume based on a plurality of geometrical parameters of the environmental FOV, an orientation of the base navigation path, and the orientation of the autonomous vehicle.

4. The method of clam 3, wherein the plurality of geometrical parameters comprises a range of LIDAR measurement, a horizontal angle of LIDAR beam elevation, a vertical angle of LIDAR beam elevation, and a height of LIDAR from the ground.

5. The method of claim 3, wherein determining the approachable volume comprises:
determining a deviation in the orientation based on the orientation of the base navigation path and the orientation of the autonomous vehicle; and
determining a scope of the environmental FOV based on the deviation.

6. The method of claim 3, further comprising filtering a navigational volume from the approachable volume, wherein the navigational volume comprises a drivable area and a plurality of non-drivable structures in the vicinity of the drivable area.

7. The method of claim 1, wherein determining the set of navigational data points comprises:
determining a plurality of data points within the navigational FOV;
along each of a plurality of pre-determined distance intervals in the navigational FOV, filtering a plurality of surface data points from the plurality of data points based on their corresponding elevation level and their corresponding base elevation level, wherein a base elevation level is an elevation on which the surface of the drivable navigation path substantially adhere to;
along each of a plurality of pre-determined distance intervals in the navigational FOV, filtering the set of navigational data points from the plurality of surface data points based on their corresponding substantially central positions.

8. The method of claim 1, wherein generating at least the portion of the drivable navigation path comprises curve fitting along the set of navigational data points.

9. The method of claim 1, further comprising navigating the autonomous vehicle based on at least the portion of the drivable navigation path.

10. The method of claim 9, wherein navigating the autonomous vehicle comprises:
determining an offset between at least the portion of the drivable navigation path and a corresponding portion of the base navigation path; and
correcting the navigation of the autonomous vehicle based on the base navigation path and the offset.

11. A system for determining a drivable navigation path for an autonomous vehicle, the system comprising:
a navigation device comprising at least one processor and a computer-readable medium storing instructions that, when executed by the at least one processor, cause the at least one processor to:
receive a base navigation path on a navigation map, a position and an orientation of the autonomous vehicle with respect to the base navigation path, and an environmental field of view (FOV);
derive a navigational FOV based on the environmental FOV, the base navigation path, and the orientation of the vehicle;
determine a set of navigational data points from the navigational FOV; and
generate at least a portion of the drivable navigation path for the autonomous vehicle based on the set of navigational data points.

12. The system of claim 11, wherein the base navigation path is received from a global positioning system (GPS) based navigation path service provider, wherein the position of the autonomous vehicle is received from a GPS sensor, wherein the orientation of the autonomous vehicle is received from an inertia measurement unit (IMU), and wherein the environmental FOV is received from a light detection and ranging (LIDAR) scanner.

13. The system of claim 11, wherein deriving the navigational FOV comprises determining an approachable volume based on a plurality of geometrical parameters of the environmental FOV, an orientation of the base navigation path, and the orientation of the autonomous vehicle.

14. The system of claim 13, wherein determining the approachable volume comprises:
determining a deviation in the orientation based on the orientation of the base navigation path and the orientation of the autonomous vehicle; and
determining a scope of the environmental FOV based on the deviation.

15. The system of claim 13, wherein the operations further comprise filtering a navigational volume from the approachable volume, wherein the navigational volume comprises a drivable area and a plurality of non-drivable structures in the vicinity of the drivable area.

16. The system of claim 11, wherein determining the set of navigational data points comprises:
determining a plurality of data points within the navigational FOV;
along each of a plurality of pre-determined distance intervals in the navigational FOV, filtering a plurality of surface data points from the plurality of data points based on their corresponding elevation level and their corresponding base elevation level, wherein a base elevation level is an elevation on which the surface of the drivable navigation path substantially adhere to;
along each of a plurality of pre-determined distance intervals in the navigational FOV, filtering the set of navigational data points from the plurality of surface data points based on their corresponding substantially central positions.

17. The system of claim 11, wherein generating at least the portion of the drivable navigation path comprises curve fitting along the set of navigational data points.

18. The system of claim 11, wherein the operations further comprise navigating the autonomous vehicle based on at least the portion of the drivable navigation path.

19. The system of claim 18, wherein navigating the autonomous vehicle comprises:
determining an offset between at least the portion of the drivable navigation path and a corresponding portion of the base navigation path; and
correcting the navigation of the autonomous vehicle based on the base navigation path and the offset.

Dated this 17th day of August, 2017

R Ramya Rao
Of K&S Partners
Agent for the Applicant
, Description:TECHNICAL FIELD
This disclosure relates generally to autonomous vehicle, and more particularly to method and system for determining a drivable navigation path for an autonomous vehicle.