Going Home Through an Unknown Street?

known ratio of 2p1 + 1=p2 (, 2:61). 1 Introduction One of the main problems in robotics is to find a path from the current location of the robot to a given target. While most of the work in this area has focussed on efficient algorithms for path planning if the robot is given a map of its environment in advance, a more natural and realistic setting is to assume that the robot has only a partial knowledge of its surroundings

Going Home Through an Unknown Street

We present a new strategy for searching for a goal in a street. The strategy works in two phases. First it follows an angular bisector, then it uses circular arcs based only on one side of the street. A competitive factor of 1.514 is achieved which is remarkably close to the lower bound of # 2. Secondly, we assume that the location of the goal is known to the robot. We prove a lower bound of # 2 on the competitive ratio of any deterministic strategy for searching in streets with known destination

Going Home Through an Unknown Street \Lambda

Abstract We consider the problem of a robot traversing an unknown polygon with the aid of standard visibility. The robot has to find a path from a starting point s to a target point t. We provide upper and lower bounds on the ratio of the distance traveled by the robot in comparison to the length of a shortest path. Since this competitive ratio is unbounded for general polygons, we restrict ourselves to the well investigated class of streets. A street is a polygon where the part of the polygon boundary from s to t is weakly visible to the part from t to s and vice versa. We consider two problems in this context. First we assume that the location of the target t is known to the robot. We prove a lower bound of p2 on the competitive ratio of any deterministic algorithm that solves this problem. This bound matches the competitive ratio for searches in a rectilinear polygon with an unknown destination which implies that