Third party funded individual grant
Acronym: EAfaults: pHRI
Start date : 01.02.2021
End date : 31.12.2022
In the last decades, elastic actuation receives increasing attention in robotics. Due to introducing flexible elements in the drive train, such actuators show beneficial capabilities for safe human-robot interaction and energy-efficient operation. Besides these advantages, practical implementations of such actuators have higher complexity than non-elastic ones and might be operated in more critical operating conditions. Due to these issues, fault sensitivity can increase but a structured analysis of how faults influence human-robot interaction is missing up to now. The project "Fault diagnosis and tolerance for elastic actuation systems: physical human-robot-interaction" aims at understanding these influences and develops control methods that enable fault tolerant interaction. It experimentally investigates the users’ stiffness experience and develops fault-tolerant control methods for reliable human-robot interaction. To this end, fault diagnosis methods from the previous project phase and psychological studies guide the development of fault-tolerant control algorithms.The influence of stiffness faults in wearable robots on user experience is examined in psychometric and psychophysical experiments. The resulting insights in human perception and human-robot interaction support the improvement of user and interaction models and guide the design of control and adaptation algorithms that facilitate safe and reliable human-robot-interaction. These fault-tolerant controllers detect stiffness faults with the previously developed diagnosis algorithms and actively compensate fault consequences. To examine the practical feasibility of the fault-tolerant physical human-robot interaction concepts, a variable stiffness actuator and an elastically actuated knee orthosis are implemented and considered.With the developed control and adaptation algorithms, an important step towards fault-tolerant human-robot interaction is performed. Moreover, the project contributes to the design and control of elastically actuated wearable robots and the understanding of users’ stiffness experience. Thereby, it supports the long-term goal of achieving intuitive and reliable motion assistance for healthy and physically challenged individuals.