I am currently working on an optimization problem which requires me to find the best train set which minimizes the forces to which it's subjected. What I'd require the genetic algorithm to do is, having a set of 29 vehicles for the train, to find the best combination which gives the lowest value of the fitness function, which takes into account both compressive and tensile forces.
However in every combination which has to be created, there have to be three fixed positions, which correspond to the three locomotives that are included in this train set (pos 1, 15 and 29). I'd like to put this condition, followed by the necessity to have each combination different from each other, into the algorithm, but I don't know how to do so.
To give an example of the structure this is an hypothetical train set:
1 4 12 6 10 8 7 9 2 3 14 11 5 13 15 25 18 21 24 19 26 28 23 16 27 20 17 22 29
and this its fitness function value: 1.1042
Any help would be much appreciated.