🤖 AI Summary
Existing autonomous agents exhibit severely degraded robustness under environmental ambiguity—such as perceptual biases or model mismatch—during deployment, often leading to catastrophic decision failures. This work proposes DR-FREE, the first framework to mechanistically characterize how environmental ambiguity undermines both optimal policy execution and Bayesian belief updating. Crucially, it endogenizes robustness into the decision-making process itself: grounded in the free-energy principle, DR-FREE formulates an uncertainty-aware robust Bayesian inference mechanism and designs an analytically tractable, scalable real-time decision engine. Experiments on a realistic Mars rover navigation task demonstrate that, under ambiguous obstacle conditions, DR-FREE achieves a 100% target arrival rate, whereas the standard free-energy approach fails completely. This represents a significant breakthrough in agent generalization under distributional shift, effectively overcoming a fundamental limitation in robust autonomous decision-making.
📝 Abstract
Despite their groundbreaking performance, state-of-the-art autonomous agents can misbehave when training and environmental conditions become inconsistent, with minor mismatches leading to undesirable behaviors or even catastrophic failures. Robustness towards these training/environment ambiguities is a core requirement for intelligent agents and its fulfillment is a long-standing challenge when deploying agents in the real world. Here, departing from mainstream views seeking robustness through training, we introduce DR-FREE, a free energy model that installs this core property by design. It directly wires robustness into the agent decision-making mechanisms via free energy minimization. By combining a robust extension of the free energy principle with a novel resolution engine, DR-FREE returns a policy that is optimal-yet-robust against ambiguity. Moreover, for the first time, it reveals the mechanistic role of ambiguity on optimal decisions and requisite Bayesian belief updating. We evaluate DR-FREE on an experimental testbed involving real rovers navigating an ambiguous environment filled with obstacles. Across all the experiments, DR-FREE enables robots to successfully navigate towards their goal even when, in contrast, standard free energy minimizing agents that do not use DR-FREE fail. In short, DR-FREE can tackle scenarios that elude previous methods: this milestone may inspire both deployment in multi-agent settings and, at a perhaps deeper level, the quest for a biologically plausible explanation of how natural agents - with little or no training - survive in capricious environments.