English

Data-driven Interpretable Hybrid Robot Dynamics

Robotics 2025-12-16 v1

Abstract

We study data-driven identification of interpretable hybrid robot dynamics, where an analytical rigid-body dynamics model is complemented by a learned residual torque term. Using symbolic regression and sparse identification of nonlinear dynamics (SINDy), we recover compact closed-form expressions for this residual from joint-space data. In simulation on a 7-DoF Franka arm with known dynamics, these interpretable models accurately recover inertial, Coriolis, gravity, and viscous effects with very small relative error and outperform neural-network baselines in both accuracy and generalization. On real data from a 7-DoF WAM arm, symbolic-regression residuals generalize substantially better than SINDy and neural networks, which tend to overfit, and suggest candidate new closed-form formulations that extend the nominal dynamics model for this robot. Overall, the results indicate that interpretable residual dynamics models provide compact, accurate, and physically meaningful alternatives to black-box function approximators for torque prediction.

Keywords

Cite

@article{arxiv.2512.11900,
  title  = {Data-driven Interpretable Hybrid Robot Dynamics},
  author = {Christopher E. Mower and Rui Zong and Haitham Bou-Ammar},
  journal= {arXiv preprint arXiv:2512.11900},
  year   = {2025}
}
R2 v1 2026-07-01T08:22:44.446Z