NSF Award
1427213
The goal of this project is to establish a user-centered optimal design framework for customized lower-extremity exoskeletons, in which human-exoskeleton physical interactions and dynamics can be predicted and optimized to provide design requirements. The objectives are to establish: (1) mathematical models of disability parameters, performance indices, and desired/task-failure motions; (2) formulations for constraint status, contact load, and coupled dynamics; (3) optimization method of contact load distribution; (4) sensor integration for required data and experimental validation; and (5) prototype design modification, fabrication, and usability tests. This research will open a new paradigm for systematic characterization of disability parameters and the desired motions from engineering perspectives, leading to user-specific mathematical models. The potential to reduce the need for involving human subjects as part of the design iteration loop will result in accelerated development and better performing assistive devices at reduced cost. Given the growing number of individuals who would benefit from customized exoskeletons as assistive devices, this project will have broad social impact by resolving major hurdles to their widespread use. This research will be integrated into comprehensive education and outreach plans for minority students and individuals with disabilities.<br/><br/>The algorithm with controlled infeasibility will provide physically valid solutions of task failure as well as desired motions for integrated human-exoskeleton systems. The concurrent formulations for constraint status/loads and coupled dynamics will resolve the problems of incorporating physical interactions into optimal motions. As a novel design method, this project will introduce optimal contact load distribution subject to exoskeleton dynamics and transformation of a complex design into a dynamically equivalent model. The feedback loops in the design framework will serve as self-evaluation/contingency plans. This research will transform exoskeleton technologies through user-centered design and predictive evaluations by systematically considering end-user requirements and limitations right from the beginning and at each stage of design. Project outcomes will represent a significant breakthrough that will bring exoskeleton technologies to the next level by (a) functioning as a central hub that systematically connects and integrates relevant disciplines; and (b) providing customized design, reduced design cycle, optimized systems with light weight and natural motion, and improved user comfort and safety.
