Special Issue on Autonomous Flying Robot

  Research on unmanned aerial vehicles (UAVs) has been conducted for quite some time, even though experiments were rather difficult to carry out. However, recent years have seen a proliferation of published reports in this field. This is most likely due to the spread of multicopters, which are easier and safer to operate than fixed-wing aircraft and single-rotor helicopters.   Other factors that have made it easier to conduct research on UAVs and thus contributed to the increased number of studies include the wide availability of high-performance flight controllers that are either low cost or offered on an open-source basis, such as ArduPilot and MultiWii.   Although this has minimized technological hurdles in conducting research, it has become more difficult to conduct research safely in a social and legal context. Prompted by a 2015 drone incident, Japan’s civil aeronautics law was revised to control UAV flights under stricter regulations. Even so, these regulations are still considered less restrictive than those in most other countries.   UAV research includes obvious risks and dangers of operating airborne devices, but also makes it more interesting as a scientific inquiry, generates high expectations about practical utility, and makes a highly significant area of investigation.   Placing a high priority on safety will hopefully lead to further research in this area.   This special issue covers the latest in UAV research, including  • UAV control system design,  • Studies on flight characteristics of aircraft equipped with special mechanisms,  • UAV applications,  • Studies on operational UAVs.  Readers will find it interesting and rewarding to explore the latest UAV research trends presented in this issue.