GEOMETRIC CONSIDERATION FOR A WAYPOINT GUIDANCE METHOD

Waypoint guidance is a technique used to steer an autonomous vehicle along a desired course. Waypoints are designated at intervals along that course. The guidance algorirthms issue steering commands that, if followed, result in the vehicle's traveling from waypoint to waypoint. Thus, the vehicle remains on or ver y close to the desired trajectory. Waypoints can be specified by latitude, longitude, and altitude in geographic coordinates. The vehicle's current location can be described similarly. This is enough information to determine the direction of travel that would take the vehicle to the waypoint. The shortest route from one point on a spherical surface to another on the same surface is a great circle. A great circle lies in a plane that contains the center of the sphere. The plane also is normal to the surface of the sphere along the great circle. The earth actually is distorted slightly from spherical; it is ellipsoidal. An ellipsoidal earth model will be used in this report. Features of the great circle will be applied to effect good approximations of shortest routes to waypoints. Therefore, only the endpoints of long, straight cuurse segments need be specified.

• Supplemental Notes:
  • Portions of this report are illegible in microfiche products.
• Corporate Authors:

  Sandia National Laboratories

  P.O. Box 5800
  Albuquerque, NM  United States  87185
• Authors:
  • PERDREAUVILLE, F J
• Publication Date: 1989-9

Media Info

• Features: Figures;
• Pagination: 14 p.

Subject/Index Terms

• TRT Terms: Advanced vehicle control systems; Advanced vehicle control systems; Altitude; Guidance systems (Aircraft); Guideways; Longitudinal control; Structural design; Trajectory; Vehicle trajectories
• Uncontrolled Terms: Guidance systems
• Old TRIS Terms: Autonomous vehicle navigation; Guideway design; Waypoint guidance
• Subject Areas: Highways; Operations and Traffic Management; Terminals and Facilities; Vehicles and Equipment; I95: Vehicle Inspection;

Filing Info

• Accession Number: 00496999
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: SAND-89-0623
• Files: TRIS
• Created Date: Sep 30 1990 12:00AM