Improving Human-Exoskeleton Fluency Through an Investigation of Dynamic Control Parameters

可穿戴机器人外骨骼有可能通过提供辅助力量来减少人类工人所承受的物理负荷，从而减少工作场所的伤害。该项目的目标是研究脚踝外骨骼在与用户交互过程中的可用性和用户心理舒适度。该设备将被编程为在人们行走和改变行走速度时提供动态支持。长期目标是开发能够推断和预测用户意图的技术，并利用这些信息来调整外骨骼的行为，以最大限度地提高用户对外骨骼系统和人-外骨骼“流畅性”的信任，定义为人类-技术团队内部行动的同步网格化。人-外骨骼的流畅性源于人与外骨骼之间的共同适应，由人在使用系统时选择的运动策略和基于人的控制策略的更新驱动。该项目的目标是研究辅助力驱动的时间和存在的不确定性如何影响人类外骨骼的流畅性和人类对外骨骼系统的信任。这项研究将对军事应用和工业应用产生影响，军事应用中，高比率的肌肉骨骼过度使用损伤威胁着军事准备，而工业应用中，肌肉拉伤、扭伤和撕裂导致了大约三分之一的报告工作日损失。通过将用户意图、人类信任和人类外骨骼流畅性模型与Dephy仿生靴相结合，该项目将通过探索外骨骼步态辅助背景下人类行为、运动控制和机器操作的基本关系，推进NSF促进科学进步和促进国民健康的使命。该项目通过外展、课程开发和指导来支持K-5、本科和研究生教育。作为开发与人类用户共同适应的预期辅助外骨骼控制器的第一步，所提出的研究的具体目标是测试人类信任和人类外骨骼流畅性受到以下假设的影响：(1)辅助力转换时间和(2)步态周期内的早、晚或错过驱动。这个项目有三个目的。第一项研究旨在评估辅助力转换时间对人类外骨骼流畅性的影响。第二个评估时间和辅助力驱动存在的不确定性如何影响人的表现和系统信任。第三个目标是开发一种协同自适应控制器，以不断提高实时的流畅性。研究小组使用市售的Dephy仿生靴和自定义控制算法来进行假设评估。这项研究将在CAREN的虚拟现实环境中进行，在一个分裂带的仪器跑步机上进行，允许自我调节。受试者将执行速度变化的任务，同时也执行双重任务，并回答旨在探究情境意识的问题。分析了人体外骨骼流畅度和信任度的新指标。这项工作可以显著改善可穿戴外骨骼系统的适应性、能力和可用性，以增强工业和军事应用中的人类性能。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。

Wearable robotic exoskeletons have potential to reduce workplace injuries by providing assistive forces that decrease the physical loads human workers experience. The goal of this project is to study the usability and user psychological comfort of an ankle exoskeleton during its interactions with its user. The device will be programmed to provide dynamic support as people walk and change walking speeds. The long term goals are to develop technology that infers and anticipates its user's intent, and to use that information to adapt the exoskeleton's behavior to maximize the user's trust in the exoskeletal system and the human-exoskeletal "fluency", defined as the synchronized meshing of actions within the human-technology team. Human-exoskeleton fluency results from the co-adaptation between the human and exoskeleton, driven by the motor strategies selected by the human when using the system and by the updates in the control policy based on the human. The goal of this project is to examine how uncertainty in the timing and presence of assistive force actuations impacts human-exoskeleton fluency and human trust in the exoskeletal system. This research will be impactful both for military applications, where high rates of musculoskeletal overuse injury threaten military readiness, and for industrial applications, where muscle strains, sprains, and tears cause about one third of the reported cases of lost work days. By integrating models of user intent, human trust, and human-exoskeleton fluency with the Dephy Bionic Boot, this project will advance the NSF mission to promote the progress of science and advance national health by exploring fundamental relationships human behavior, motor control, and machine manipulation within the context of exoskeletal gait assistance. The project supports K-5, undergraduate and graduate education through outreach, curriculum development, and mentorship.As a first step towards developing an anticipatory assistive exoskeleton controller that co-adapts with its human user, the specific objective of the proposed research is to test the hypotheses that human trust and human-exoskeleton fluency are affected by (1) assistive force transition timing and (2) early, late, or missed actuations within the gait cycle. This project has three aims. The first seeks to evaluate the effect of variations in assistive force transition timing on human-exoskeleton fluency. The second evaluates how uncertainty in the timing and presence of assistive force actuations impacts human performance and system trust. The third aim develops a co-adaptive controller that seeks to continuously increase fluency in real-time. The research team uses the commercially available Dephy Bionic Boot with custom control algorithms to permit hypothesis evaluation. The study will be performed within a CAREN virtual reality environment on a split-belt, instrumented treadmill that permits self-pacing. Subjects will perform speed changing tasks while also performing dual tasks and responding to questions designed to probe situation awareness. New measures of human-exoskeleton fluency and trust are analyzed. This work could lead to significant improvements in the adaptability, capability, and usability of wearable exoskeletal systems for human performance enhancement in industrial and military applications.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.