Introduction to the special issue on HRI system studies

Human-Robot Interaction (HRI) systems are often realized through a complex integration of relevant state-of-the-art algorithms, low-level software and robotic hardware. As such, advances in techniques and approaches for integrating components into a robotic system are essential to advance the field. To develop such techniques and systems requires one to address real-world challenges, particularly those arising from the complex nature of human-robot interaction embedded in a dynamic social and/or task environment. This special issue focuses on the concept of "systems", highlighting the importance of building actual HRI systems to validate and drive the science and technology in the field.