An execution control method for the Aerostack aerial robotics framework

Execution control is a critical task of robot architectures which has a deep impact on the quality of the final system. In this study, we describe a general method for execution control, which is a part of the Aerostack software framework for aerial robotics, and present technical challenges for execution control and design decisions to develop the method. The proposed method has an original design combining a distributed approach for execution control of behaviors(such as situation checking and performance monitoring) and centralizes coordination to ensure consistency of the concurrent execution. We conduct experiments to evaluate the method. The experimental results show that the method is general and usable with acceptable development efforts to efficiently work on different types of aerial missions. The method is supported by standards based on a robot operating system(ROS) contributing to its general use, and an open-source project is integrated in the Aerostack framework. Therefore, its technical details are fully accessible to developers and freely available to be used in the development of new aerial robotic systems.

Unclonable human-invisible machine vision markers leveraging the omnidirectional chiral Bragg diffraction of cholesteric spherical reflectors

The seemingly simple step of molding a cholesteric liquid crystal into spherical shape,yielding a Cholesteric Spherical Reflector(CSR),has profound optical consequences that open a range of opportunities for potentially transformative technologies.The chiral Bragg diffraction resulting from the helical self-assembly of cholesterics becomes omnidirectional in CSRs.This turns them into selective retroreflectors that are exceptionally easy to distinguish-regardless of background--by simple and low-cost machine vision,while at the same time they can be made largely imperceptible to human vision.This allows them to be distributed in human-populated environments,laid out in the form of QR-code-like markers that help robots and Augmented Reality(AR)devices to operate reliably,and to identify items in their surroundings.At the scale of individual CSRs,unpredictable features within each marker turn them into Physical Unclonable Functions(PUFs),of great value for secure authentication.Via the machines reading them,CSR markers can thus act as trustworthy yet unobtrusive links between the physical world(buildings,vehicles,packaging...).and its digital twin computer representation.This opens opportunities to address pressing challenges in logistics and supply chain management,recycling and the circular economy,sustainable construction of the built environment,and many other fields of individual,societal and commercial importance.