In PSO, the population size refers to the number of particles (or individuals) within the swarm. It has significant impact on speed of convergence and quality of solution.
Convergence Speed
Larger population sizes tend to lead to faster convergence because of the coverage of the search space. However, the convergence speed diminishes as the population size is excessively large.
Exploration and Exploitation
Large population size allow greater exploration, but reduces exploitation efficiency as particles may be influenced to focus on non-promising regions instead of intensely focusing promising regions.
Solution Quality
Larger population has higher quality solutions because of their diverse exploration ability, yet it may lead to unnecessary computational loads, slowing down optimisation process.
Try it yourself!
Experimental Results:
In conclusion, population size plays a critical role in shaping the performance of PSO convergence speed, solution quality, and especially computation overhead.