  Self-adaptive parameters are increasingly used in the field of Evolutionary
Robotics, as they allow key evolutionary rates to vary autonomously in a
context-sensitive manner throughout the optimisation process. A significant
limitation to self-adaptive mutation is that rates can be set unfavourably,
which hinders convergence. Rate restarts are typically employed to remedy this,
but thus far have only been applied in Evolutionary Robotics for mutation-only
algorithms. This paper focuses on the level at which evolutionary rate restarts
are applied in population-based algorithms with more than 1 evolutionary
operator. After testing on a real hexacopter hovering task, we conclude that
individual-level restarting results in higher fitness solutions without fitness
stagnation, and population restarts provide a more stable rate evolution.
Without restarts, experiments can become stuck in suboptimal controller/rate
combinations which can be difficult to escape from.
