# 동적 환경을 위한 A* 알고리즘 기반의 경로 및 속도 프로파일 설계

• 권민혁 (고려대학교 전자전기컴퓨터공학과) ;
• 강연식 (국민대학교 자동차공학과) ;
• 김창환 (한국과학기술연구원) ;
• 박귀태 (고려대학교 전기전자전파공학부)
• Accepted : 2011.03.29
• Published : 2011.05.01

#### Abstract

This paper presents a hierarchical trajectory planning method which can handle a collision-free of the planned path in complex and dynamic environments. A PV (Path & Velocity profile) planning method minimizes a sharp change of orientation and waiting time to avoid a collision with moving obstacle through detour path. The path generation problem is solved by three steps. In the first step, a smooth global path is generated using $A^*$ algorithm. The second step sets up the velocity profile for the optimization problem considering the maximum velocity and acceleration. In the third step, the velocity profile for obtaining the shortest path is optimized using the fuzzy and genetic algorithm. To show the validity and effectiveness of the proposed method, realistic simulations are performed.

#### References

1. Jur P. van den Berg and M. H. Obermars, "Roadmapbased motion planning in dynamic environments," IEEE, Transactions on Systems, man and Cybernetics, vol. 21, no. 5, pp. 885-897, Oct. 2005. https://doi.org/10.1109/TRO.2005.851378
2. B. Damas and J. Sntos-Victor, "Avoiding moving obstacles: the forbidden velocity map," IEEE, RSJ Int. Conf. on Intelligent Robots and Systems, pp. 4393-4398, Oct. 2009. https://doi.org/10.1109/IROS.2009.5354210
3. S. Koenig and M. Likhachev, "Fast replanning for navigation in unknown terrain," IEEE, Transactions on Robotics and Automation, vol. 21, no. 3, pp. 354-363, June 2005. https://doi.org/10.1109/TRO.2004.838026
4. O. Dahl and L. Nielsen, "Torqe-limited path following by on-line trajectory time scaling," IEEE, Transactions on Robotics and Automation, vol. 6, pp. 554-561, Oct. 1990. https://doi.org/10.1109/70.62044
5. B. H. Lee, and C. S. G. Lee, "Collision-free motion planning of two robots," IEEE Transactions on Systems, Man, and Cybernetics, vol. 17, no. 1, pp. 21-32, Jan. 1987. https://doi.org/10.1109/TSMC.1987.289330
6. S. C. Zaharakis and A. Guez, "Time optimal robot navigation via the slack set method," IEEE Transactions on Systems, Man, and Cybernetics, vol. 20, no. 6, pp. 1396-1407, Nov./Dec. 1990. https://doi.org/10.1109/21.61209
7. M. Kwon, H. Lim, Y. Kang, C. Kim, and G. Park, "Hierarchical optimal time path planning method for a autonomous mobile robot using A* algorithm," IEEE, International Conference on Control, Automation and Systems, pp. 225-233, Oct. 2010.
8. K. Belarbi, F. Titel, W. Bourebia, and K. Benmahammed, "Design of Mamdani fuzzy logic controllers with rule base minimisation using genetic algorithm," Engineering Applications of Artificial Intelligence, vol. 18, no. 7, pp. 875-880, Oct. 2005. https://doi.org/10.1016/j.engappai.2005.03.003
9. R. A Brook and T. Lorenzo-Perez, "A subdivision algorithm inconfiguration space for findpath with rotation," IEEE Transactions on Systems,Man and Cybernetics, vol. SMC-15(2), pp. 225-233, Mar./Apr.1985.
10. A* Pathfinding for Beginners, http://www.policyalmanac. org/games/aStarTutorial.htm.
11. M. Deloura, "Game Progarmming Gems," Information Publishing Group, Seoul, pp. 340-381, 2001.
12. D. Fox, W. Burgard, F. Dellaert, and S. Thrun, "Monte carlo localization: Efficient position estimation for mobile robots," Proc. of the National Conference on Artificial Intelligence (AAAI'99), 1999.
13. S. Paolo and L. Riccardo, "Configuration spaces are not homotopy invariant," Topology, vol. 44, no. 2, pp. 375-380, Mar. 2005. https://doi.org/10.1016/j.top.2004.11.002
14. I. Kim, "Obstacle avoidance and local path planning for mobile robots using the fast elastic band," Journal of Institute of Control, Robotics and Systems(in Korean), vol. 16, no. 8, pp. 794-798, Aug. 2010. https://doi.org/10.5302/J.ICROS.2010.16.8.794