NRI: INT: Collaborative Research: An Open-Source Framework for Continuous Torque Control of Intuitive Robotic Prosthetic Legs

该项目将建立一套开源软件控制算法，使开源机器人假肢能够促进人类用户与环境之间有节奏和无节奏的交互。这个项目建立在开源Leg的基础上，这是一个强大的、廉价的机器人腿平台，可以很容易地制造、组装和编程。该项目的首要目标是实现由用户身体的运动持续提示的可定制行为。该项目通过为兼容执行器创建开源控制硬件和软件，扩展了开源Leg的功能，从而促进了科学的进步。顺应扭矩控制的优势，结合用户直观、富有表现力的控制，比目前可用的假肢腿有了显著的改进。该项目将通过开发和测试高级控制软件来推进国民健康，该软件将允许开源腿的用户无缝地绕过障碍并执行动态活动。这些技术提供的移动性改善将改善许多行动不便者的生活质量和功能能力。开源硬件和软件降低了机器人技术的准入门槛，这使得这些机器人不仅可以作为医疗保健和其他应用中的辅助协作机器人，还可以作为本科生和研究生的教育工具。新兴的动力假肢，如nsf资助的开源Leg，其马达可以恢复膝盖以上截肢者的正常生物力学，但这些设备受其控制策略的限制，只能进行一小组预定义的稳态活动。每个活动通常被划分为称为阶段的步态周期的离散进展，导致大量不同的控制器努力与用户持续协调假肢运动。离散控制范式不能促进活动之间的过渡等短暂行为，也不能促进后退或跨越障碍等无节奏运动。最近出现了一种新的控制范式，基于用户身体（例如残肢）的惯性测量，不断同步或协调假肢运动给用户。然而，先前的实现仅限于实验室特定的义肢设计，具有刚性执行器，严格执行从用户运动到义肢关节位置的运动学映射，而不是遵循不同的环境相互作用。最近开发的开源Leg提供了一个独特的机会，将这种最先进的控制范例集成在一个普遍可访问的试验台中，该试验台具有一系列弹性致动器，可软化用户，假肢和环境之间的相互作用。该项目的总体目标是：1)了解如何在开源腿的系列弹性致动器中实现闭环扭矩和阻抗控制，尽管其低成本设计未建模动态；2)了解如何将高保真关节阻抗控制与两个新型连续控制器集成，从而允许用户灵活无缝地导航障碍物并执行动态活动。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project will establish an open source set of software control algorithms that will allow an open source robotic prosthetic leg to facilitate rhythmic and non-rhythmic interactions between the human user and the environment. This project builds upon the Open-Source Leg, which is a robust, inexpensive, robotic leg platform that can be easily manufactured, assembled, and programmed. The project's overarching goal is to enable customizable behaviors that are continuously cued by the movement of the user’s body. The project promotes the progress of science by creating open source control hardware and software for compliant actuators that extend the capabilities of the Open-Source Leg. The advantages of compliant torque control, combined with intuitive, expressive control from the user, represents a significant improvement over currently-available prosthetic legs. The project will advance the national health by developing and testing high-level control software that will allow users of the Open Source Leg to seamlessly navigate around obstacles and perform dynamic activities. The improved mobility provided by these technologies will improve the quality of life and functional capabilities of many people living with mobility impairment. Open source hardware and software lower barriers to access for robotic technologies, which makes these robots great candidates not only as assistive co-robots in healthcare and other applications but also as educational tools for undergraduate and graduate students.Emerging powered prostheses such as the NSF-funded Open-Source Leg have motors that can restore normative biomechanics to above-knee amputees, but these devices are limited by their control strategies to a small set of pre-defined, steady-state activities. Each activity is typically divided into a discrete progression of gait periods called phases, resulting in a large set of distinct controllers that struggle to continuously coordinate prosthetic limb motion with the user. Discrete control paradigms have not been able to facilitate transient behaviors like transitions between activities or non-rhythmic motions like stepping backwards or stepping over obstacles. Recently, a new control paradigm has emerged that continuously synchronizes or coordinates prosthetic limb motion to the user based on inertial measurements from the user’s body (e.g., the residual limb). However, prior implementations have been limited to lab-specific prosthetic leg designs with stiff actuators that rigidly enforce the kinematic mappings from user motion to prosthetic joint position rather than complying to varying environmental interactions. The recently developed Open-Source Leg presents a unique opportunity to integrate this state-of-the-art control paradigm in a universally accessible testbed with series elastic actuators that soften interactions between the user, prosthesis, and environment. The overall goals of this project are to 1) understand how to achieve closed-loop torque and impedance control in the series elastic actuator of the open-source leg despite unmodeled dynamics from its low-cost design, and 2) understand how to integrate high-fidelity joint impedance control with two novel continuous controllers that promise to allow users to flexibly and seamlessly navigate obstacles and perform dynamic activities.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.