This chapter presents a new sensor-based path planner, which gives a fast local or global motion plan
capable to incorporate new obstacles data. Within the first step, the safest areas in the environment are
extracted by means of a Voronoi Diagram. Within the second step, the fast marching method is
applied to the Voronoi extracted areas so as to get the trail. This strategy combines map-based and
sensor-based designing operations to supply a reliable motion plan, whereas it operates at the
frequency of the sensor. The most interesting characteristics are high speed and reliability, as the map
dimensions are reduced to a virtually one-dimensional map and this map represents the safest areas
within the environment.