Communication in modular robotic motor control: Bilateral controllers under realistic constraints

2026-08-13

AI Summary

This study addresses robotic control architecture selection under noise and energy constraints by proposing a bio-inspired bilateral modular controller modeled after cerebral hemispheres. The method employs dual GRU modules with learnable delayed communication channels, trained end-to-end within a differentiable musculoskeletal simulator. Results demonstrate that this modular architecture significantly outperforms monolithic baselines. Furthermore, the introduction of learnable communication effectively enhances endpoint accuracy in bimanual reaching and holding tasks while reducing energy consumption and muscle co-contraction under non-zero delay conditions. These findings underscore the critical role of inter-module communication in balancing the trade-offs among precision, stability, and energy efficiency for robust robotic control.

Abstract

Robotic motor control in musculoskeletal systems requires fast, accurate movement and robust postural stabilization under signal-dependent noise (where motor command variance scales with command magnitude) and energetic cost. Modular controllers can distribute these competing demands across interacting submodules, but it remains unclear whether they outperform monolithic architectures under realistic constraints, and how inter-module communication shapes the resulting strategy. Inspired by the bilateral hemispheric organization of the brain, we introduce a recurrent controller of two GRU-based modules connected by a learnable, delayed inter-hemispheric channel, trained end-to-end in a differentiable two-arm musculoskeletal simulator. Across reaching and holding tasks, the modular architecture substantially outperforms a capacity-matched monolithic baseline. Compared to a matched modular controller without communication, learned inter-hemispheric communication reshapes the solution: improved endpoint precision, lower energetic cost in non-zero-delay regimes, and reduced muscle co-contraction. Our findings show that for robotics, biologically inspired modular controllers offer a practical route to robust movement under noise and energetic constraints, with inter-module communication providing a mechanism to tune trade-offs between precision, stability, and actuation cost.

Problem

• Modular robotic motor control
• Musculoskeletal systems
• Inter-module communication
• Signal-dependent noise
• Energetic cost

Innovation

• Modular Controller
• Inter-module Communication
• Bilateral Architecture
• Signal-dependent Noise
• Musculoskeletal Simulation