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arXiv 2602.23670cs.ROcs.SYeess.SY
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嵌入物理的神经ODE用于学习对抗性气动人工肌肉动力学

Physics-Embedded Neural ODEs for Learning Antagonistic Pneumatic Artificial Muscle Dynamics

Dept. of Mechanical Engineering, University of California, Riverside, CA, USA(加州大学河滨分校机械工程系)

Xinyao Wang, Jonathan Realmuto

AI总结:

本文提出了一种嵌入物理结构的神经ODE框架,用于学习对抗性气动人工肌肉的动力学,实现了高精度的刚度控制和阻抗行为。

摘要:

气动人工肌肉(PAMs)能够为软可穿戴、辅助和交互机器人提供柔性驱动。当以对抗方式排列时,PAMs可通过协同收缩提供可变阻抗,但表现出耦合、非线性和滞后动力学,这对建模和控制构成挑战。本文提出了一种混合神经普通微分方程(Neural ODE)框架,将物理结构嵌入到对抗性PAM动力学的学习模型中。该公式结合了参数关节力学和气动状态动力学,以及一个神经网络力组件,以捕捉对抗耦合和速率依赖的滞后。前向模型在225种协同收缩条件下预测关节运动和腔体压力,均方R²为0.88。逆向公式从学习的动力学中推导出,用于离线计算所需压力命令,以实现期望的运动和刚度剖面,在执行过程中通过闭环跟踪。实验验证显示,在126-176 N/mm范围内实现了可靠的刚度控制,并在操作速度下表现出一致的阻抗行为,与静态模型相比,静态模型在更高速度下表现出降级的刚度一致性。

英文摘要:

Pneumatic artificial muscles (PAMs) enable compliant actuation for soft wearable, assistive, and interactive robots. When arranged antagonistically, PAMs can provide variable impedance through co-contraction but exhibit coupled, nonlinear, and hysteretic dynamics that challenge modeling and control. This paper presents a hybrid neural ordinary differential equation (Neural ODE) framework that embeds physical structure into a learned model of antagonistic PAM dynamics. The formulation combines parametric joint mechanics and pneumatic state dynamics with a neural network force component that captures antagonistic coupling and rate-dependent hysteresis. \rev{The forward model was trained on 29 selected co-contraction conditions and predicted joint motion and chamber pressures over 196 held-out conditions with a mean R$^2$ of 0.88.} An inverse formulation, derived from the learned dynamics, computes pressure commands offline for desired motion and stiffness profiles, tracked in closed loop during execution. Experimental validation demonstrates reliable stiffness control across 126-176 N/mm and consistent impedance behavior across operating velocities, in contrast to a static model, which shows degraded stiffness consistency at higher velocities.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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