Page 151 - Innovations in Intelligent Machines
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142    A. Pongpunwattana and R. Rysdyk
                               4                                 4
                                                  step = 6                           step = 20
                              3.5                 time = 600    3.5                  time = 2000
                               3                                2.5 3
                             Latitude (deg)  1.5 2  1  1       Latitude (deg)  1.5 2  1 1
                              2.5



                               1                                 1
                              0.5                               0.5
                               0                                 0
                                10 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15  10 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15
                                        Longitude (deg)                    Longitude (deg)
                                            (a)                                (b)
                               4                                 4
                                                    step = 27                        step = 39
                              3.5                               3.5
                                                    time = 2700  3                   time = 3900
                               3
                             Latitude (deg)  2.5 2  1  1       Latitude (deg)  2.5 2  1  1


                              1.5
                               1                                1.5 1
                              0.5                               0.5
                               0                                 0
                                10 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15  10 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15
                                         Longitude (deg)                    Longitude (deg)
                                            (c)                                (d)
                                 Fig. 24. Snapshots of dynamic path planning with moving obstacles


                           to avoid collision with the obstacles and successfully observe the target and
                           finally reach the goal location. The expected value of the loss function at each
                           time step is given in Figure 25. The first spike in the plot occurs when the
                           obstacles start moving. The planner dynamically replans the path with a lower
                           loss value according to the new updated information about the environment.



                           7 Conclusion

                           The goal of this work is to develop a dynamic path planning algorithm for
                           autonomous vehicles operating in changing environments. The algorithm must
                           be capable of replanning during the operation. We present the concept of
                           dynamic path planning and a framework to solve the planning problem based
                           on a model-based predictive control scheme. We describe a model used to
                           predict the expected values of future states of the system. The model takes
                           into account the uncertain information of the environment and the dynamics
                           of the system.
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