Page 69 - Innovations in Intelligent Machines
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58     P.B. Sujit et al.
                           Theorem 2. The negotiation terminates in a finite number of negotiation
                           cycles.
                           Proof. From Theorem 1 we observe that, at each negotiation cycle, at least
                           one of the agents gets all accept and so decides upon a target for its next step.
                           Since there are a finite number of agents, in a finite number of negotiation
                           cycles each agent would decide upon a target to attack. If the target are not
                           available then they continue to search task. Hence, all the agents would decide
                           upon a task in a finite number of negotiation cycles. The maximum number
                           of negotiation cycles an agent can go through is N.


                           4.3 Simulation Results

                           A simulation study is conducted on a battlefield scenario of size 100 × 100.
                           Through these simulations we show that the negotiation scheme performs
                           better than greedy strategy in terms of average number of targets destroyed.
                           The simulation is carried out using 7 UAVs for 100 different sets of target posi-
                           tions with each set having 20 targets. The a priori knowledge about number
                           of targets present in the space and their initial positions are not available to
                           the UAVs. We also study the performance of negotiation and greedy schemes
                           for various sensor radius.
                              From Figure 5 we can see that the negotiation scheme outperforms the
                           greedy strategy. The number of targets using negotiation scheme is higher and


                                  20
                                                   Ns = 30
                                  18                 r   Ns r = 20
                                                  and s =40
                                                      r
                                                Ns r =10                G s = 40 = 50
                                 Average number of targets destroyed  12 8  G s = 20 G s = 30
                                  16
                                                                          G s r
                                              Ns =50
                                                r
                                  14
                                                                          r
                                                                    r
                                  10
                                                               r
                                   6
                                   4
                                            G s = 10
                                               r
                                   2                                   G   > Greedy strategy
                                                                       N  > Negotiation scheme
                                   0
                                    0     50     100     150    200     250    300    350
                                                   Time taken to destroy targets
                                Fig. 5. Average number of target hits for 100 different target positions
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