重新思考外骨基于模拟的设计:使用不同的成本函数的影响
概括
对被动膝关节外骨架的基于模拟的设计需要先进的方法. 标准的轨迹跟踪阻碍了步态的适应,但多目标的方法可以提高模拟的准确性,并确定最佳的设计,以节省代谢能量.
科学领域:
- 生物力学和机器人技术
- 人与机器的互动 人与机器的互动
- 外骨架的设计和模拟
背景情况:
- 外骨设计通常依赖于实验方法,这些方法耗时且昂贵.
- 基于模拟的设计为优化外骨参数提供了一个有希望的替代方案.
- 现有的模拟方法经常使用全轨迹跟踪,这可能不会准确地反映外骨架的步态适应.
研究的目的:
- 研究完整轨迹跟踪和模拟用被动膝关节外骨架跑步的多目标优化之间的差异.
- 开发和验证一种新的多目标成本函数,以提高步态模拟的准确性.
- 确定一个被动膝关节外骨的最佳设计参数,以最大限度地节省代谢能量.
主要方法:
- 使用了2D OpenSim模型,具有10个自由度和18个肌肉,加上Moco优化工具.
- 测试了在全轨迹跟踪目标函数中不同重量的影响.
- 开发了一种多目标的成本函数,其中包含一个基于摇摆期间膝盖峰值角度的脚间距术语.
主要成果:
- 完整的轨迹跟踪,即使是低重量,在模拟中也阻止了显著的步态适应.
- 新的多目标成本函数实现了与实验数据相似的模拟步行轨迹 (RMSE=7.4度).
- 一个带有2.5Nm/deg弹的被动膝关节外骨架设计,在净代谢能量方面表现出高达8%的改善.
结论:
- 成本函数中的标准轨迹跟踪目标限制了模拟预测外骨与外骨架的步态适应的能力.
- 多目标优化为模拟外骨辅助运动和确定最佳设计提供了更有效的方法.
- 超越简单的轨迹跟踪的预测模拟方法是推动外骨发展所必需的.
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