I have a doubt regarding the convergence pattern of the fitness function in fig 1.
The algorithm converged just around the 2nd iteration. a major probability of this trend can be due to the fact that it got trapped in the local optimum and converged prematurely. Kindly correct me if I am wrong!
If it's case as you describe it i'm a gree with your conclusion, for this i suggest you a solution of this problem. Please take look at links in the subject.
-Particle Swarm Optimization - Soft Computing and Intelligent ...
You may understand the basic and step by step procedure of PSO algorithm in a very simple manner through the following video. See and wait for my next update.