Rezazadeh Siavash, Quintero David, Divekar Nikhil, Gregg Robert D
Locomotor Control Systems Laboratory, Departments of Bioengineering and Mechanical Engineering, The University of Texas at Dallas, Richardson, TX 75080, USA.
Rep U S. 2018 Oct;2018:2292-2298. doi: 10.1109/IROS.2018.8594023. Epub 2019 Jan 7.
Although there has been recent progress in control of multi-joint prosthetic legs for periodic tasks such as walking, volitional control of these systems for non-periodic maneuvers is still an open problem. In this paper, we develop a new controller that is capable of both periodic walking and common volitional leg motions based on a piecewise holonomic phase variable through a finite state machine. The phase variable is constructed by measuring the thigh angle, and the transitions in the finite state machine are formulated through sensing foot contact together with attributes of a nominal reference gait trajectory. The controller was implemented on a powered knee-ankle prosthesis and tested with a transfemoral amputee subject, who successfully performed a wide range of periodic and non-periodic tasks, including low- and high-speed walking, quick start and stop, backward walking, walking over obstacles, and kicking a soccer ball. The proposed approach is expected to provide better understanding of volitional motions and lead to more reliable control of multi-joint prostheses for a wider range of tasks.
尽管在多关节假肢腿用于诸如行走等周期性任务的控制方面最近取得了进展，但对于这些系统进行非周期性动作的自主控制仍然是一个未解决的问题。在本文中，我们基于一个通过有限状态机的分段完整相位变量，开发了一种既能进行周期性行走又能实现常见自主腿部动作的新型控制器。该相位变量通过测量大腿角度构建而成，有限状态机中的转换则通过感知足部接触以及名义参考步态轨迹的属性来制定。该控制器在一个动力膝盖 - 脚踝假肢上实现，并由一名经大腿截肢的受试者进行测试，该受试者成功完成了广泛的周期性和非周期性任务，包括低速和高速行走、快速启动和停止、向后行走、越过障碍物行走以及踢足球。所提出的方法有望为自主动作提供更好的理解，并导致对多关节假肢在更广泛任务中的更可靠控制。
