NRI: Collaborative Research: Unified Feedback Control and Mechanical Design for Robotic, Prosthetic, and Exoskeleton Locomotion

人们迫切需要可穿戴机器人，例如假肢和外骨骼，它们可以改善行动不便的个人的生活质量——这些设备可以与人类用户共生，实现稳定、安全和高效的运动。目前，由于中风、脊髓灰质炎、多发性硬化症、脊髓损伤和脑瘫的影响，美国大约有470万人将受益于活跃的下肢外骨骼，到2050年，美国估计有150万人将患有下肢截肢。然而，目前的可穿戴机器人设备并不能满足这一不断增长的人口需求，因为它们体积庞大、重量重、噪音大，即使是短时间使用也需要大电池，同时主要采用分层控制算法。传统的设计-构建-测试方法忽略了硬件规格和控制算法性能之间的紧密耦合，这种方法昂贵且缓慢，阻碍了该领域的创新。这项工作的愿景是提供一种方法——受到机器人运动进步的启发——通过机电和反馈系统的共同设计，使下肢假肢和外骨骼能够满足现实世界的要求。因此，这项工作的变革性质源于其实现可穿戴机器人的能力，这些机器人可以与人类协同实现更高的移动性，为不断发展的机器人辅助设备行业提供模板，并有可能改善数百万人的生活质量。为了实现这项工作的愿景，总体研究目标是创建一个新的统一控制和设计框架，使机器人、假肢和外骨骼能够高效稳定地运动。这种控制方法的一个关键方面是能够通过（可穿戴）机器人设备、其环境和用户之间基于力的相互作用，在不同目标之间以有效的方式持续调解，从而实现稳定性和安全性。所得到的框架将通过具有严格设计要求的假体和外骨骼的环控机械设计，在新型类人机器人上进行实验测试，并通过人体受试者试验进行临床评估。因此，这项工作以下列具体目标为指导：(1)为（可穿戴）机器人运动开发一个统一的在线优化控制框架，有效地调节稳定性、安全性和力约束；(2)在可穿戴机器人的形式控制综合和机械设计之间建立一个反馈回路，满足严格的性能要求；(3)通过将两足人形机器人的控制器正式和实验地转化为假肢和外骨骼，加速临床试验。由于这些研究目标，这项工作有可能创造下一代机器人系统，使人类能够稳定、安全和高效地移动。

There is a pressing need for wearable robots, e.g., prostheses and exoskeletons, which improve the quality of life for individuals with limited mobility - devices that work symbiotically with human users to achieve stable, safe and efficient locomotion. At present, approximately 4.7 million people in the United States would benefit from an active lower-limb exoskeleton due to the effects of stroke, polio, multiple sclerosis, spinal cord injury, and cerebral palsy, and by 2050 an estimated 1.5 million people in the United States will be living with a major lower-limb amputation. Yet current wearable robotic devices do not address this growing population's needs since they are bulky, heavy, noisy, and require large batteries for even short duration use, while implementing predominately hierarchical control algorithms. Impeding innovation in this domain is the expensive and slow traditional design-build-test approach that ignores the tight coupling between hardware specifications and control algorithm performance. The vision of this work is to provide a methodology---inspired by advancements in robotic locomotion---that allows lower-limb prostheses and exoskeletons to meet real-world requirements through the co-design of the electromechanical and feedback systems. The transformative nature of this work, therefore, stems from its ability to realize wearable robots that synergize with humans to achieve increased mobility, providing a template for the growing robotic assistive device industry and potentially improving the quality of life of millions. To realize the vision of this work, the overarching research goal is to create a new unified control and design framework that will allow for the efficient and stable locomotion of robots, prostheses, and exoskeletons. A key aspect of this control methodology is the ability to continuously mediate between different objectives enforcing stability and safety in an efficient manner through force-based interactions among (wearable) robotic devices, their environment and the user. The resulting framework will be utilized via control-in-the-loop mechanical design of prostheses and exoskeletons with stringent design requirements, tested experimentally on a novel humanoid robot, and clinically evaluated through human subject trials. This work is, therefore, guided by the following specific goals: (1) develop a unified online optimization-based control framework for (wearable) robotic locomotion that efficiently mediates stability, safety and force constraints, (2) create a feedback loop between formal control synthesis and the mechanical design of wearable robots that satisfy stringent performance requirements, (3) accelerate clinical testing by translating controllers formally and experimentally from bipedal humanoid robots to prostheses and exoskeletons. As a result of these research goals, this work has the potential to create the next generation of robotic systems that enable stable, safe and efficient human mobility.