Page 174 - Innovations in Intelligent Machines
P. 174

166    S. Rathinam and R. Sengupta
                              Once, this path is followed, the UAV reaches the position (¯x(d j ), ¯(d j )) at
                                                                                      y
                           some final angle θ and this angle is chosen as the heading at the final position.
                              The algorithm MV A for the RAP(m) is as follows:

                            1. Construct a complete graph with vertices being all the UAVs and desti-
                               nations. Assign the Euclidean distance as the cost to each edge that joins
                               a UAV to a destination and a destination to a destination. Assign zero
                               cost to an edge that joins any two UAVs.
                            2. Find the minimum spanning tree of the graph using Prim’s algorithm [2].
                               This minimum spanning tree will contain exactly m − 1 zero cost edges
                               where m is the number of UAVs (Fig. 17).
                            3. Remove the zero cost edges to get a tree for each UAV (Fig. 18).
                            4. For each tree corresponding to a UAV, double its edges to construct a
                               Eulerian graph (Fig. 19). Then construct a tour for each UAV based on
                               the Eulerian graph. A tour for each UAV is a sequence of destinations for
                               it to visit (Fig. 20). (This step is similar to tour construction for the single
                               TSP discussed in section 2.3).
                            5. Use the above sequence and construct paths using algorithm S between
                               any two consecutive locations. For example, use algorithm S to construct
                               a path from (x(v 1 ),y(v 1 ),α 1 )to(¯x(d 1 ), ¯y(d 1 )). Say, the UAV reaches the

                                1. Calculate the Euclidean TSP tour  2. Fix the headings at each destination



















                                                                          UAV
                                                                          destination






                                   3. Construct  the Dubinspath between any two consecutive
                                       destinations on the Euclidean TSP tour
                                         Fig. 16. Alternating Algorithm for the RAP(1)
   169   170   171   172   173   174   175   176   177   178   179