Many researches which have been done within this field, some of them used a “visibility graph” to set up a configuration space that can be mapped into a graph of vertices between which travel is possible in a straight line. The disadvantage of this method is time consuming. At the opposite, some researches have been based on dividing the world map into a grid and assign a cost to each square. Path cost is the sum of the cost of the grid squares through which the path passes. A grid model has been adopted by many authors, where the robot environment is divided into many squares and indicated to the presence of an object or not in each square [6, 9].