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.

  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.

  The construction industry is one of the largest economicalsectors in developed countries. The economical contributionof the construction industry is comparable withthe contribution of the manufacturing industry. However,the construction industry is one of the most unfamiliar areasof R&D in the robotics community. The first ideasfor construction robots appeared in the 1970s in Japan.Due to quality problems of construction works, lack ofskilled labor, low productivity, numerous accidents andfatalities and high construction demand, the first prototypesof construction robots were developed towards theend of the 1970s. Since then more than 200 constructionrobots and service robots for buildings have been developed,but only about 10% of them have been successfullyintroduced to the construction market. The developmentof on-site robots in the 1980s peaked with the developmentof integrated automated building construction sitesin the 1990s. In the beginning of the 21st century humanoidrobots were researched and tested. In the futurewe will see robots that care for the elderly and handicappedas a further development of construction robots.
  This issue gives an overview on the state of art ofrobotic technologies in construction. The introductoryarticle also relates the construction robotics developmentto the industrial robotics technology in the prefabricationsector of the 1970s, gives examples of various constructionrobotics developments of the 1980s, the integratedautomated building construction sites since the 1990s, andthe humanoid construction robotics developments and integratedindustrialization efforts of recent date. Roboticsubtechnologies such as programming, sensors, kinematics,teleoperation, navigation, human-robot interaction arepresented to the reader. During the last years much efforthas been devoted to the application of robots and roboticstechnology in construction works. Most of them are forout-door application, where the tasks are developed incomplex unstructured environments and under hazardousconditions. The construction robots introduced during thelast years have dramatically improved labor conditions,productivity and quality levels, and also have increasedthe safety conditions for operators. The nowadays constructionrobotics technology tries to take advantage ofthe last developments for control, navigation, localization,human-machine interface or sensor use. Howeverrobotics in construction is still a very challenging topic inorder to clarify many unsolved R&D issues.
  The purpose of this special issue is to provide a reviewof open issues and new developments in robotics inconstruction, ranging from major construction engineeringprojects to residential building construction:

•   • Robotics for building construction.
•   • Robotics for civil engineering: roads, bridges, earthmoving, etc.
•   • Inspection, maintenance and infrastructures robots.
•   • Navigation, mapping and localization of robots inconstruction environments.
•   • Technology components for construction robots: 3Dsensors, end-effectors, HMI, control strategies, cooperation,safety, etc.

Intelligent automobiles equipped with active safety methods whose objective is to reduce accidents caused by human problems such as careless driving and loss of consciousness, have got the social acceptance widely which are recognized by introducing collision avoidance brakes to the market. Active safety and automated driving technologies of intelligent automobiles were featured at TokyoMotor Show 2015. Their displays attracted much attention.
It is necessary to propose new technologies continuously by the technical subject of active safety and automated driving, for example, relation of cooperative driving by a vehicle system and a driver, from the restrictions of originality of technical developments and the liability issues at the time of an accident.
Even so, users worldwide expect much from the dynamic future of transportation for safety and active life.
This special issue features seven papers carefully reviewed by field specialists.I would like to express my heartfelt appreciation to the authors who have contributed their valuable research results to this special issue and to the reviewers who provided their invaluable expertise.
I would also like to thank members of the Journal of Robotics and Mechatronics board for giving me the unique opportunity to plan and coordinate this issue.

The first Tsukuba Challenge started in 2007 as a technological challenge for autonomous mobile robots moving around on city walkways. A task was then added involving the search for certain persons. In these and other ways, the challenge provides a test field for developing positive relationships between mobile robots and human beings. To make progress an autonomous robotic research, this special issue details and clarifies technological problems and solutions found by participants in the challenge. We sincerely thank the authors and reviewers for this chance to work with them in these important areas.

Robot vision is an important robotics and mechatronics technology for realizing intelligent robot systems that work in the real world. Recent improvements in computer processing are enabling environment to be recognized and robot to be controlled based on dynamic high-speed, highly accurate image information. In industrial application, target objects are detected much more robustly and reliably through high-speed processing. In intelligent systems applications, security systems that detect human beings have recently been applied positively in computer vision. Another attractive application is recognizing actions and gestures by detecting human – an application that would enable human beings and robots to interact and cooperate more smoothly when robots observe and assist human partners. This key technology could be used for aiding the elderly and handicapped in practical environments such as hospital, home, and so on. This special issue covers topics on robot vision and motion control including dynamic image processing. These articles are certain to be both informative and interesting to robotics and mechatronics researchers. We thank the authors for submitting their work and for assisting during the review process. We also thank the reviewers for their dedicated time and effort.

According to the aged society in Japan, the expectation is high for the development of the human support robot or devices in daily life and in medical treatment and welfare. The human centered design and the universal design are very important concept for creating the useful human support devices. Human centric and universal designs are the designs of products and environments to be usable by all people, to the greatest extent possible, without the need for adaptation or specialized design. This special issue provides current researches and developments of human centric, universal and interactive design for robotics and mechatronics. Also, this special issue covers a broad range of research topics, such as human centric design, universal and interactive design, human machine interaction, transport system, housing environment system, rehabilitation devices, multi modal interface, evaluation of the usability, sensor/actuator technologies for assistive system, robotics and mechatronics to support elderly persons. We thank the authors for their fine contributions and the reviewers for their generous time and effort. In closing, we thank the Editorial Board of the Journal of Robotics and Mechatronics for helping make this issue possible.

As a disaster-prone country, Japan has endured many earthquake disasters. The latest cases include the 1995 Great Hanshin-Awaji earthquake disaster, the 2004 Niigata Chuetsu earthquake, and the 2011 Great East Japan earthquake. Since the 1995 Great Hanshin-Awaji earthquake in particular, many robot researchers have started undertaking the research and development of rescue robots. Their practical applications have a long way to go, so to continue ongoing robot research and development, we should also be aware that comparatively few researchers and engineers are actually engaged in such research and development. Great earthquakes (or tsunami) are both rare and unpredictable, which makes it very difficult to establish research policies for rescue robots intended for specialized use in disaster response. We should also realize that Japan is almost constantly hit by one or another every year – e.g., the typhoons that hit Japan directly every year and themselves triggering other disasters caused by landslides or avalanches due to heavy rainfall. The Japanese populace is so accustomed to such happenings but, nevertheless, few actions have been taken unlike those against large-scale earthquakes. It is often said that an effective disaster response system can only be developed after we have experienced many actual disasters. It then occurs to us that we must first construct disaster response systems – rescue robots, etc. – directly targeting daily natural disasters. Any large-scale disaster response system can be built on such constant efforts. On the other hand, any disaster response system against daily natural disasters could only be developed by locally domiciled researchers and engineers. This makes us feel that it is possible to increase the number of personnel who become involved in disaster response research and development. Based on the above context, this special issue provides a wide range of articles on region-specific disasters and disaster response actions, focusing on their localities and specialties. We sincerely hope that this special issue will help in promoting research and development on rescue robots and putting them to practical use.