Lower-limb prosthesis wearers are more prone to falling than non-amputees. Powered prostheses can reduce this instability of passive prostheses. While shown to be more stable in practice, powered prostheses generally use model-independent control methods that lack formal guarantees of stability and rely on heuristic tuning. Recent work overcame one of the limitations of model-based prosthesis control by developing a class of provably stable prosthesis controllers that only require the human interaction forces with the prosthesis, yet these controllers have not been realized with sensing of these forces in the control loop. Our work realizes the first model-dependent prosthesis knee controller that uses in-the-loop on-board real-time force sensing at the interface between the human and prosthesis and at the ground. The result is an optimization-based control methodology that formally guarantees stability while enabling human-prosthesis walking on a variety of terrain types. Experimental results demonstrate this force-based controller outperforms similar controllers not using force sensors, improving tracking across 4 terrain types.
翻译:低脂假肢磨损器比非抗药性穿戴器更容易下降。 有动力的假肢可以减少被动假肢的不稳定性。 虽然在实际操作中显示比较稳定,但有动力的假肢通常使用模型独立的控制方法,这些方法缺乏对稳定性的正式保障,并依赖休眠调节。最近的工作克服了基于模型的假肢控制的局限性之一,它开发了一类只要求人类与假肢互动力量的、可证实稳定的假肢控制器,但这些控制器在控制循环中对这些力量的感知中并没有实现。我们的工作实现了第一个模型依赖的假肢膝控制器,在人与假肢和地面的界面使用机内实时武力感测。结果是一种基于优化的控制方法,它正式保证了稳定性,同时使人类假肢控制器能够在各种地形类型上行走。实验结果表明,这种基于力量的控制器在不使用力感应传感器的情况下超越了类似的控制器。