Mobile robot navigation in enclosed large-scale space

Journal ArticleIn a large-scale s ace, navigation may occur among very dispersed landmarks, further apart than the range of sensing of an autonomous vehicle. In this work we investigate the feasibility of construction of a landmark-based cognitive map, whose elements are the obstacles perceived by a robotic vehicle during exploration of an unknown, large-scale environment. This cognitive map can then be used as an aid for goal-oriented navigation in such a challenging environment. A map construction algorithm is described suitable for a mobile robot with the ability of temporarily marking a single location in an enclosed environment containing polygonal objects. The algorithm is being verifies with a LEGO-Technic-based autonomous vehicle, equipped with a 2 d.0.f. arm and relying on inaccurate odometric and short-range proximity sensing . In spite of its limited and inaccurate internal and external sensing abilities basic skills experimentally demonstrated by the robot include pick-and-place of a portable marker, obstacle detection, as well as characterization and recognition of polygonal objects. These skills, in conjunction with the approximate odometric measurements collected by the vehicle, also represent the repertoire of behaviors exploited in map-assisted navigation

Integration of fault tolerance and hardware redundancy techniques into the design of mobile platforms

This work addresses the development of a fault-tolerant mobile platform. Fault-tolerant mechanical system design is an emerging technology that attempts to build highly reliable systems by incorporating hardware and software architectures. For this purpose, previous work in fault-tolerant were reviewed. Alternate architectures were evaluated to maximize the fault tolerance capabilities of the driving and steering systems of a mobile platform. The literature review showed that most of the research work on fault tolerance has been done in the area of kinematics and control systems of robotic arms. Therefore, hardware redundancy and fault tolerance in mobile robots is an area to be researched. The prototype constructed as part of this work demonstrated basic principles and uses of a fault-tolerant mechanism, and is believed to be the first such system in its class. It is recommended that different driving and steering architectures, and the fault-tolerant controllers\u27 performance be tested on this prototype