Real-Time Path Planning and Terrain Obstacle Avoidance for General Aviation Aircraft Conference Paper uri icon


  • To reduce the work load of Air Traffic Controllers, a new concept called Free Flight has emerged. This system takes the load off of the air traffic controller and puts the responsibility on the pilot. To help the pilot handle this responsibility in the General Aviation implementation of Free Flight, there is a focus on cockpit agents that advise and assist the pilot in functions such as obstacle avoidance. This paper develops a real-time discrete-node heuristic search method for optimal path planning with terrain obstacle avoidance, specifically tailored for General Aviation class aircraft equipped for Small Aircraft Transportation System operation. This approach determines the optimal path between the nodes with respect to a set of cost factors and constraints. The algorithm runs fast enough and without significant computational burden so as to be run online in the limited computing power, dynamic environment expected for future General Aviation aircraft. Several techniques are applied to increase the computation speed to the desired level. A variable resolution terrain grid is used to allow low resolution path planning when possible, and higher resolution when necessary. Additionally, the search nodes are only created on demand which reduces memory usage and setup time by restricting the search space to the minimum necessary. The demonstration program uses digital elevation terrain data for path planning with terrain avoidance. The method used, however, is extensible and can be applied to any kind of obstacle, static or dynamic. Results are presented for a set of test cases using various terrain configurations and show that the algorithm has the capability to find quality solutions within a reasonable time period on modest PC hardware. The resolution of the generated path can be changed to enable higher quality solutions or lower computing requirements.

name of conference

  • AIAA Guidance, Navigation, and Control Conference and Exhibit

published proceedings

  • AIAA Guidance, Navigation, and Control Conference and Exhibit

author list (cited authors)

  • Doebbler, J., Gesting, P., & Valasek, J.

citation count

  • 18

complete list of authors

  • Doebbler, James||Gesting, Paul||Valasek, John

publication date

  • June 2005