Page 48 - Read Online
P. 48

Ortiz et al. Intell Robot 2021;1(2):131-50  I http://dx.doi.org/10.20517/ir.2021.09     Page 141


               Using Equation (42), we have


                                                       ∗
                                       (     +1 ) ≤   (      ≠    ∀0 <    ≤     )(1 −   )
                                               ∗                      2
                                     ≤   (      ≠    ∀0 <    ≤ (   − 1)  )(1 −   )
                                               ∗                  ∗                  
                                     ≤   (      ≠    ∀0 <    ≤ 0)  (      ≠    ∀0 <    ≤   )(1 −   )
                                       1
                                     =      (1 −   )   
               where   (      ≠    ∀0 <    ≤ 0) = 1, then
                             ∗

                                                                 1        
                                                lim   (     +1 ) ≤ lim (1 −   )
                                                  →∞            →∞    
                                                              
                                                =  1  lim (1 −   ) = 0
                                                    
                                                     →∞
               Since 0 <    ≤ 1, the algorithm converges exponentially to    in: population size    and iteration number   .
                                                               ∗
               The algorithm of the SLAM-based roadmap GA for the path planning is as follows.


               SLAM based roadmap GA. (1) Initiate population randomly   (  ) of size    that belong in set   . (2) The
               fitness value is         with Euclidean distance for each chromosome      . (3) The population is from lower to
               higher fitness:        (   1 ) ≥        (   2 ) ≥ · · · ≥        (      ). (4) Crossing set in the chromosomes,       ∩       →         ,        .
               (5) Next population   (   + 1) is replaced by the chromosomes with poor skills. (6) Random mutation with
               poor skills. (7) Go to Step (2)




               4.   AUTONOMOUS NAVIGATION
               Our AN uses both sliding mode SLAM (Algorithm 1) and the roadmap GA method (Algorithm 2). The
               autonomous navigation algorithm is:


               Autonomous navigation. The initial state      , the target          =                     (   1 ),    =                     (   2 )    =
                                                                                     +
                                                                  −
               gain sliding mode,       = search radius        =search_obstacles(      ,       )       = Path_Planning(      ,       ,       )    0 =
               Controller(      ,       ) while       ≠      
                                                                         −  +
                                              ˆ
                                                  ,       =     _               ,       ,      ,    ,    ,   ,      
                                                                           
                                                                              
                                  ˆ
                           =            (end state)           (       :           ℎ(          ))  =             [     
                     ] =Path_Planning(      ,       ,       )  if       >           =                                       (      ,       ,       ,       )
                                                                 ˆ
               end if;         +1 = Controller(      ,       ) end while return       ,      
               The PP needs the map, robot position, and target. This information is given by the sliding mode SLAM algo-
               rithm. When the algorithm falls into a local solution, we use the                                        function to provide
               another       which is outside the local zone.



               5.   COMPARISONS

               Inthis section, we use several examples to compare our method with the three other recent methods: the polar
               histogram method for path planning [50] , the grid method for path planning [51] , and SLAM with extended
               Kalman filter [52] .
   43   44   45   46   47   48   49   50   51   52   53