arXiv:2410.07200cs.ROcs.SY2024-10被引 4

针对外骨骼机器人建模误差问题,提出一种高效鲁棒的轨迹控制方法。

A Realistic Model Reference Computed Torque Control Strategy for Human Lower Limb Exoskeletons

  • 基于参考模型的计算力矩控制,分离慢速预测与快速校正环路
  • 实验显示轨迹跟踪精度高,对参数不确定性具有强鲁棒性
  • 适合神经康复场景中需高稳定性与低延迟的外骨骼应用

外骨骼机器人在神经康复中展现出巨大潜力,可提供有效物理治疗与恢复监测。其疗效依赖于精确的运动控制。尽管基于逆动力学的计算力矩控制具备坚实的理论基础,但其实际应用受限于对模型精度的敏感性,尤其在应对不可预测负载时表现不佳。为此,本文提出一种新型模型参考计算力矩控制器,兼顾参数不确定性容忍度与计算效率。构建了七自由度下肢外骨骼动态模型,引入真实关节摩擦模型以准确反映机器人物理行为。为降低计算负担,控制架构分为两个回路:慢速回路根据输入轨迹与机器人动力学预测关节力矩需求,快速回路采用PID实时校正轨迹跟踪误差。由于科里奥利力与离心力对系统动态影响极小,且计算成本较高,故从模型中移除。实验结果表明,轨迹跟踪精度高,统计分析证实控制器在参数不确定条件下仍具鲁棒性与有效性。该方法为提升外骨骼神经康复系统的稳定性与性能提供了新路径。

原文摘要 · Abstract (English)

Exoskeleton robots have become a promising tool in neurorehabilitation, offering effective physical therapy and recovery monitoring. The success of these therapies relies on precise motion control systems. Although computed torque control based on inverse dynamics provides a robust theoretical foundation, its practical application in rehabilitation is limited by its sensitivity to model accuracy, making it less effective when dealing with unpredictable payloads. To overcome these limitations, this study introduces a novel model reference computed torque controller that accounts for parametric uncertainties while optimizing computational efficiency. A dynamic model of a seven-degree-of-freedom human lower limb exoskeleton is developed, incorporating a realistic joint friction model to accurately reflect the physical behavior of the robot. To reduce computational demands, the control system is split into two loops: a slower loop that predicts joint torque requirements based on input trajectories and robot dynamics, and a faster PID loop that corrects trajectory tracking errors. Coriolis and centrifugal forces are excluded from the model due to their minimal impact on system dynamics relative to their computational cost. Experimental results show high accuracy in trajectory tracking, and statistical analyses confirm the controller's robustness and effectiveness in handling parametric uncertainties. This approach presents a promising advancement for improving the stability and performance of exoskeleton-based neurorehabilitation.

外骨骼控制算法神经康复

Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。