Sustainable robot foraging: Adaptive fine-grained multi-robot task allocation for maximum sustainable yield of biological resources

We introduce the concept of Maximum Sustainable Yield (MSY) to the context of autonomous robot foraging. MSY is an optimal approach to the problem of maximizing sustainable foraging where the resources harvested are replenished by logistic growth, e.g. living things. Over-harvesting reduces both the instantaneous resource availability and growth rate, and above some threshold will permanently deplete resources. Under-harvesting is sustainable, but fails to maximally exploit the resources. We describe a system model and use it to determine the optimal allocation of robot work to resource-producing `patches´. We give a practical illustration of a troublesome feature of MSY: it is too sensitive for a fixed allocation to be sustainable in practice. We show how to centrally allocate a number of robots to each patch, and then locally adapt the work rate of each robot to achieve sustainable and near-optimal foraging. This is the first study of robot foraging where the robots´ activity modifies the productivity and sustainability of the environment.