Tham khảo tài liệu 'aerial vehicles part 13', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 592 Aerial Vehicles 3. A weighting factor a embedding the Pop-Up appearance probability when flying towards its location. We have chosen the product combination based in the assumption that all the ADUs work in cooperation. N P r. V au. r. V TT R. r. V 23 LS1 r v al SPU r v n I1 Si r v o i 1 The weighting factor a ranging in 0 1 is defined as the complementary probability of the pop-up appearance probability PAPU at any state r v of the aircraft 24 . It should be strictly greater than zero and less than one because the fact to exactly assign any of these values to a PAPU probability makes the ADU turn into a nonexistent or fixed one respectively which is already considered in the last term of the product. a 1 - Papu 24 Then it is clear that the more probable a pop-up arises in front of the UAV during the flight the less probable the UAV will survive to it bringing a greater cumulative mean risk to the chosen trajectory. Once the total survival probability to a set of N cooperating ADUs is computed including the unexpected activation of more threats the total probability of kill Pi T in the state m r v is given by the complement to one 25 . PKTm r V 1 - PsTm r V 25 Hence we define the cumulative mean risk of a trajectory RK as the average of the total kill probabilities of all the M points which form this trajectory 26 . This concept will be used as a parameter to characterize the group of alternatives to build a final trajectory under a decision making formulation. 1 M K M PKTm r V 26 The risk is calculated as a mean value based on the discrete time system assumption. The points of the trajectory are approximately equally spaced since the flying speed is constant. If the time were continuous the integral form to calculate a mean value would be used instead of the sum showed in 26 . Cumulative flying time parameter The flying time parameter is simply a way to characterize alternative trajectories in terms of the cumulative time needed by the aircraft to achieve