Question L5-C1

The question is about the choice of algorithm for global path planning of a robot transporting parcels in a building. The question is: "You have to design a robot that transports parcels from one office to another in the same building. You need to compute its path from the parcel reception to the destination office, passing through some large rooms. You have all the plans, including the furniture which are in fixed positions. Of course you need to find the shortest path. Which path planner do you choose?". Three possibilities are proposed:

Answer A. "Visibility graph on obstacles that are enlarged by half of the diameter of the robot and Dijkstra applied on the graph". This answer is correct, as this is the only proposed solution that ensures an optimal path.
In the explanation of the student we would like to see that they understand that a visibility graph allows to generate optimal paths, what a grid-based approach cannot.

Answer B. "Dijkstra on a 0.1x0.1m2 four-connected occupancy grid". This answer is wrong, as this will generate displacements that have only vertical and horizontal displacements, creating a path that is not optimal.
In the explanation of the student we would like to see that they understand that a "four-connected occupancy grid" is allowing only vertical and horizontal displacements, generating a path that is not optimal.

Answer C. "A* also on a 0.1x0.1m2 four-connected occupancy grid" This answer is wrong, as this will generate displacements that have only vertical and horizontal displacements, creating a path that is not optimal.
In the explanation of the student we would like to see that they understand that a "four-connected occupancy grid" is allowing only vertical and horizontal displacements, generating a path that is not optimal.
