Tunable Parameters

The novelty engine has three parameters that have changed at different points in the experiment.

• MAXGEN. Every time the foreground server ends a generation, it fetches ten new rookies, the current champions-vs.-robots, to become part of the main population. To avoid the effects of convergence, which could lead to the same agents being sent repeatedly, the background population is restarted every once in a while. The novelty engine checks the number of generations g that the present population has been evolving for. If g > MAXGEN, then the present population is killed and evolution starts with a fresh random population.
• f. When the novelty engine restarts, it fetches f new agents from the foreground that become the fixed part of the training set.
• SEED. This is a boolean parameter. Upon restart of the coevolutionary run, either 1000 new random agents are created or, if SEED is true, the current 100 champions-against-people are reintroduced along with 900 random ones -- the foreground population is used as a seed for the background.