Ant Colony Optimisation(ACO) for optimising PID. Minimising Integral absolute control error

I am trying to use ACO in order to obtain good load disturbance rejection response by minimising integral absolute control error. The plant used in my simulation is the nomoto first order ship model. The results currently being obtained are not satisfactory and i was wondering if someone may take a look at my ACO parameters and code to see how i can get more satisfactory results. I have attavhed the corresponding files below.