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放源码的软件控制算法，允许开放源码的机器人假肢促进人类用户与环境之间的有节奏和无节奏的互动。这个项目建立在开源腿的基础上，这是一个健壮、廉价的机械腿平台，可以轻松地制造、组装和编程。该项目的主要目标是实现可定制的行为，这些行为可以通过用户身体的移动来连续提示。该项目通过为符合要求的执行器创建开放源代码控制硬件和软件来促进科学进步，从而扩展了开放源代码分支的能力。顺应性扭矩控制的优势，与用户直观、富有表现力的控制相结合，代表着对目前可用的假肢的重大改进。该项目将通过开发和测试高级控制软件来促进国民健康，这些软件将使开源腿的用户能够无缝地绕过障碍物并进行动态活动。这些技术提供的改善的移动性将改善许多行动不便的人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使用门槛，这使得这些机器人不仅是医疗保健和其他应用中的辅助合作机器人，也是本科生和研究生的教育工具。新兴的电动假肢，如NSF资助的开放源代码腿，具有马达，可以恢复膝盖以上截肢者的标准生物力学，但这些设备的控制策略限于一小部分预定义的稳定活动。每个活动通常被划分为称为阶段的步态周期的离散序列，从而产生一大组不同的控制器，这些控制器努力不断地协调假肢与用户的运动。离散控制范例不能促进瞬间行为，如活动之间的转换，或非节奏运动，如后退或跨过障碍物。最近，已经出现了一种新的控制范例，其基于来自用户身体(例如，残肢)的惯性测量来持续地向用户同步或协调假肢运动。然而，以前的实现一直局限于具有刚性致动器的特定于实验室的假肢设计，该致动器严格执行从用户运动到假肢关节位置的运动学映射，而不是遵守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，可以将这一最先进的控制范例集成到一个普遍可访问的试验床中，该试验床带有一系列弹性执行器，可以软化用户、假肢和环境之间的交互。该项目的总体目标是：1)了解如何在开放源码支腿的串联弹性执行器中实现闭环力矩和阻抗控制，尽管其低成本设计具有未建模的动力学；2)了解如何将高保真联合阻抗控制与两个承诺允许用户灵活无缝地穿越障碍物和执行动态活动的新型连续控制器集成在一起。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.