Design and Validation of Two-Stage Motion Control System for By-Air Quantum Key Distribution*

In this paper, we present a dynamic visual servo control for receiver and transmitter positioning in a by-air quantum key distribution network using a robot manipulator. We discuss the positioning system with pre-alignment and fine-positioning stages. At the pre-alignment stage, the use of image-based visual servoing and dynamic controllers with payload variation is considered. We consider the use of two classical controllers (PD+ gravity and computed-torque controller) and an additional simple time-delay controller. As a fine-positioning stage, we describe approaches that can be used for precise adjustment of a transmitter. We conclude the paper with simulation results using a model of 5-dof robot manipulator KUKA youBot.