Special Issue on Real World Robot Challenge in Tsukuba – Autonomous Technology for Coexistence with Human Beings –

This issue is the third in a series on Real World Robot Challenge in Tsukuba. The Tsukuba Challenge has contributed much in establishing autonomous mobile robot control technology on outdoor walkways where robots must mingle with pedestrians and cyclists – not all of whom may be familiar with such robots. The rain on the day of the final run for the 2015 Tsukuba Challenge taught us valuable lessons in navigating robots in real environments. Since the 2013 Tsukuba Challenge, a new task was introduced in the second stage. This task consists of searching for human targets – a technological challenge for developing robots that are both mobile and useful. Our objective here is to share advanced control technology refined through experiments in the real-world environment of the Tsukuba Challenge. The Tsukuba Challenge is also providing a forum for technological education for university students studying robotics engineering and for technical exchange through open experiments. In this issue, we are pleased to present the control technology that this exchange has brought about. We would like to express our deep gratitude to the authors contributing to this issue and to the article reviewers who have helped make this all possible.