“…Considering the environment uncertainty that is difficult if not impossible to model, fuzzy logic is one of the most widely used mathematical tools for autonomous vehicle navigation (Driankov & Saffiotti, 2001). Fuzzy logic techniques have already been used and are being used currently for autonomous navigation of ground (indoors (Aguire & Gonzalez, 2000;Doitsidis, et al, 2002;Goodridge & Luo, 1994;Ishikawa, 1991;Li, 1994;Oriolo, et al, 1998;Pin & Watanabe, 1994;Tsourveloudis, et al, 2001;Tunstel, 1996) and outdoors (Hagras, et al, 2001;Seraji & Howard, 2002;Valavanis, et al, 2005), aerial (fixed (Doitsidis, et al, 2004;Nikolos, et al, 2003a) and rotary wings (Amaral, 2001;Hoffmann, et al, 1999;Kadmiry & Driankov, 2001;Kadmiry & Driankov, 2004;Sugeno, 1999) and water (surface (Vanick, 1997) or submersible (Kanakakis, et al, 2004;Kanakakis, et al, 2001)) robotic vehicles. The wide applicability of fuzzy logic in autonomous navigation is mainly based on suitable knowledge representation of inherently vague notions achieved through fuzzy IF-THEN rules.…”