Learning-Based Robust Control: Unifying Exploration and Distributional Robustness for Reliable Robotics via Free Energy
Authors: Hozefa Jesawada, Giovanni Russo, Abdalla Swikir, Fares Abu-Dakka
Organizations: Mechanical Engineering Program, New York University Abu Dhabi, Abu Dhabi, UAE. · Department of Information and Electrical Engineering & Applied Mathematics, University of Salerno, Fisciano, Italy. · Mohammed bin Zayed University for Artificial Intelligence, Abu Dhabi, UAE.
A key challenge towards reliable robotic control is devising computational models that can both learn policies and guarantee robustness when deployed in the field. Inspired by the free energy principle in computational neuroscience, to address these challenges, we propose a model for policy computation that jointly learns environment dynamics and rewards, while ensuring robustness to epistemic uncertainties. Expounding a distributionally robust free energy principle, we propose a modification to the maximum diffusion learning framework. After explicitly characterizing robustness of our policies to epistemic uncertainties in both environment and reward, we validate their effectiveness on continuous-control benchmarks, via both simulations and real-world experiments involving manipulation with a Franka Research~3 arm. Across simulation and zero-shot deployment, our approach narrows the sim-to-real gap, and enables repeatable tabletop manipulation without task-specific fine-tuning.
Figures & tables
Fig. 1 : Modifying Maximum Diffusion RL with Distributionally Robust Free Energy Principle to address epistemic uncertainty, narrowing sim-to-real gaps for reliable robotics.
Fig. 2 : overview of the proposed control loop. At each step, the agent collects data into a replay buffer, updates the dynamics and cost models, computes the maximally diffusive kernel pmax , and solves the min–max optimization. The resulting twisted kernel produces an action that is applied to the system, and the cycle repeats.
Fig. 3 : HalfCheetah results. Top: training performance of the proposed algorithm vs. MaxDiff RL on HalfCheetah-v5 (mean ± 1 STD over n=20 runs). Middle: rollout frames from the proposed algorithm showing a stable stride reaching the target. Bottom: rollout frames from MaxDiff RL illustrating an unstable gait leading to failure.
Fig. 4 : Franka obstacle-avoidance results with the proposed method. Top: learning curves showing episode return and minimum distance to goal (success threshold 5 cm, mean ± 1 STD over n=20 runs). Bottom: i) a rollout demonstrating collision-free manipulation around the obstacle. ii) trajectory plot with goal orientation highlighted in cyan, magenta, and yellow, illustrating efficient training and task execution.
Fig. 5 : Deployment on the Franka Research 3 for cluttered tabletop pick-and-place. Top: grasp at the first goal and place at the second. Bottom: with an obstacle, the controller lifts to avoid collision and completes the placement.
Metric
ϱ=0
0.5
1
5
100
1000
2000
Normalized Avg. Episode Cost ( ↓ )
1.87
1.01
1.00
1.24
9.50
56.8
148
Standard Deviation
0.076
0.014
0.055
0.099
7.96
11.4
28.3
Success Rate ( ↑ )
100%
100%
100%
80%
60%
20%
0%
TABLE S-1 : Performance across ϱ over 5 trials. Episode cost is normalized to the best case ( ϱ=1 ). A trial succeeds if the robot reaches the goal while staying ≥0.07 ,m from all obstacle centers throughout the episode.
Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM 87106, USA · Los Alamos National Lab, Los Alamos, NM 87547, USA