Finite-State Impedance and Direct Myoelectric Control for Robotic Ankle Prostheses: Comparing Their Performance and Exploring Their Combination
Finite-State Impedance and Direct Myoelectric Control for Robotic Ankle Prostheses: Comparing Their Performance and Exploring Their Combination
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DOI：
10.1109/tnsre.2023.3287971
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发表时间：
2023-06
影响因子：
4.9
通讯作者：
Ryan R. Posh;J. Schmiedeler;Patrick M. Wensing
中科院分区：
文献类型：
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作者：
Ryan R. Posh;J. Schmiedeler;Patrick M. Wensing
非意志控制，例如有限状态机（FSM）阻抗控制，不直接结合用户意图信号，而意志控制，例如直接肌电控制（DMC），则依赖于这些信号。本文针对有和没有小腿截肢的受试者，对机器人假肢上的 FSM 阻抗控制与 DMC 的性能、功能和感知进行了比较。然后，使用相同的指标，探索在整个步态周期中 FSM 阻抗控制和 DMC 组合的可行性和性能，称为混合意志控制 (HVC)。在对每个控制器进行校准和适应后，受试者步行两分钟，探索控制能力，并完成一份调查问卷。 FSM阻抗控制产生比DMC（0.88 Nm/kg和0.94 W/kg）更大的平均峰值扭矩（1.15 Nm/kg）和功率（2.05 W/kg）。然而，离散 FSM 会产生非标准的动力学和运动学轨迹，而 DMC 产生的轨迹在质量上更类似于健全的生物力学。在使用 HVC 行走时，所有受试者都成功实现了脚踝推出，并能够通过意志输入调节推出的幅度。然而，出乎意料的是，HVC 的表现要么更类似于 FSM 阻抗控制，要么更类似于单独的 DMC，而不是组合起来。 DMC 和 HVC（但不包括 FSM 阻抗控制）允许受试者实现独特的活动，如踮脚尖站立、跺脚、侧步和向后行走。身体健全的受试者 (N=6) 的偏好在控制者之间分散，而所有经胫骨的受试者 (N=3) 更喜欢 DMC。期望的性能和易用性与总体满意度的相关性最高（分别为 0.81 和 0.82）。
Non-volitional control, such as finite-state machine (FSM) impedance control, does not directly incorporate user intent signals, while volitional control, like direct myoelectric control (DMC), relies on these signals. This paper compares the performance, capabilities, and perception of FSM impedance control to DMC on a robotic prosthesis for subjects with and without transtibial amputation. It then explores, using the same metrics, the feasibility and performance of the combination of FSM impedance control and DMC across the full gait cycle, termed Hybrid Volitional Control (HVC). After calibration and acclimation with each controller, subjects walked for two minutes, explored the control capabilities, and completed a questionnaire. FSM impedance control produced larger average peak torque (1.15 Nm/kg) and power (2.05 W/kg) than DMC (0.88 Nm/kg and 0.94 W/kg). The discrete FSM, however, caused non-standard kinetic and kinematic trajectories, while DMC yielded trajectories qualitatively more similar to able-bodied biomechanics. While walking with HVC, all subjects successfully achieved ankle push-off and were able to modulate the magnitude of push-off via the volitional input. Unexpectedly, however, HVC behaved either more similarly to FSM impedance control or to DMC alone, rather than in combination. Both DMC and HVC, but not FSM impedance control, allowed subjects to achieve unique activities such as tip-toe standing, foot tapping, side-stepping, and backward walking. Able-bodied subject (N=6) preferences were split amongst the controllers, while all transtibial subjects (N=3) preferred DMC. Desired performance and ease of use showed the highest correlations with overall satisfaction (0.81 and 0.82, respectively).