| Popis: |
Physical human-robot interaction (pHRI) interfaces are responsible for ensuring safe, comfortable, and effective force transfer between wearable devices and their users. However, analysis is often oversimplified by treating the human-robot attachment as a rigid connection and using gross load measurements. As a result, information about the distribution of forces across the human-robot contact surface is lost. In this paper, we present an analysis method to predict distributed loading across a pHRI interface based on a model with discretized elastic elements that account for compliance from human soft tissue and the robot attachment. Stiffness properties of a proxy upper arm are measured with an indenter and used in the pHRI interface model. The analysis is performed assuming a rigid arm model, consistent with the underlying assumption in literature, and repeated using the proposed compliant arm model with measured elastic properties. The distributed loading predicted by the pHRI interface model is validated with measurements from a sensorized upper arm cuff on the Harmony exoskeleton. Our results reveal that a model incorporating compliance at the human-robot attachment is necessary to improve prediction of distributed interface loads. This motivates the need for human-centered analysis which can enable finer control of interaction forces and help design more ergonomic attachment interfaces. |
