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arXiv · 2510.21164

An Agnostic End-Effector Alignment Controller for Robust Assembly of Modular Space Robots

Shamistan Karimov·Elian Neppel·Shreya Santra·Kentaro Uno·Kazuya Yoshida
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Abstract

Modular robots offer reconfigurability and fault tolerance essential for lunar missions, but require controllers that adapt safely to real-world disturbances. We build on our previous hardware-agnostic actuator synchronization in Motion Stack to develop a new controller enforcing adaptive velocity bounds via a dynamic hypersphere clamp. Using only real-time end-effector and target pose measurements, the controller adjusts its translational and rotational speed limits to ensure smooth, stable alignment without abrupt motions. We implemented two variants, a discrete, step-based version and a continuous, velocity-based version, and tested them on two MoonBot limbs in JAXA's lunar environment simulator. Field trials demonstrate that the step-based variant produces highly predictable, low-wobble motions, while the continuous variant converges more quickly and maintains millimeter-level positional accuracy, and both remain robust across limbs with differing mechanical imperfections and sensing noise (e.g., backlash and flex). These results highlight the flexibility and robustness of our robot-agnostic framework for autonomous self-assembly and reconfiguration under harsh conditions.

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Shamistan Karimov, Elian Neppel, Shreya Santra, Kentaro Uno, Kazuya Yoshida. 2025-10-24. An Agnostic End-Effector Alignment Controller for Robust Assembly of Modular Space Robots. https://arxiv.org/abs/2510.21164

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