Keyframe-based monocular SLAM: design, survey, and future directions

Extensive research in the field of monocular SLAM for the past fifteen years has yielded workable systems that found their way into various applications in robotics and augmented reality. Although filter-based monocular SLAM systems were common at some time, the more efficient keyframe-based solutions are becoming the de facto methodology for building a monocular SLAM system. The objective of this paper is threefold: first, the paper serves as a guideline for people seeking to design their own monocular SLAM according to specific environmental constraints. Second, it presents a survey that covers the various keyframe-based monocular SLAM systems in the literature, detailing the components of their implementation, and critically assessing the specific strategies made in each proposed solution. Third, the paper provides insight into the direction of future research in this field, to address the major limitations still facing monocular SLAM; namely, in the issues of illumination changes, initialization, highly dynamic motion, poorly textured scenes, repetitive textures, map maintenance, and failure recovery

Dynamic Optimized Bandwidth Management for Teleoperation of Collaborative Robots

A real-time dynamic and optimized bandwidth management algorithm is proposed and used in teleoperated collaborative swarms of robots. This method is effective in complex teleoperation tasks, where several robots rather than one are utilized and where an extensive amount of exchanged information between operators and robots is inevitable. The importance of the proposed algorithm is that it accounts for Interesting Events (IEs) occurring in the system\u27s environment and for the change in the Quality of Collaboration (QoC) of the swarm of robots in order to allocate communication bandwidth in an optimized manner. A general dynamic optimized bandwidth management system for teleoperation of collaborative robots is formulated in this paper. The suggested algorithm is evaluated against two static algorithms applied to a swarm of two humanoid robots. The results demonstrate the advantages of dynamic optimization algorithm in terms of task and network performance. The developed algorithm outperforms two static bandwidth management algorithms, against which it was tested, for all performance parameters in 80% of the performed trials. Accordingly, it was demonstrated that the proposed dynamic bandwidth optimization and allocation algorithm forms the basis of a framework for algorithms applied to real-time highly complex systems

Determining crystal structures through crowdsourcing and coursework

We show here that computer game players can build high-quality crystal structures. Introduction of a new feature into the computer game Foldit allows players to build and real-space refine structures into electron density maps. To assess the usefulness of this feature, we held a crystallographic model-building competition between trained crystallographers, undergraduate students, Foldit players and automatic model-building algorithms. After removal of disordered residues, a team of Foldit players achieved the most accurate structure. Analysing the target protein of the competition, YPL067C, uncovered a new family of histidine triad proteins apparently involved in the prevention of amyloid toxicity. From this study, we conclude that crystallographers can utilize crowdsourcing to interpret electron density information and to produce structure solutions of the highest quality

Natural gait generation techniques for multi-bodied isolated mechanical systems

Abstract — This paper investigates how to generate cyclic gaits for multi-bodied isolated mechanical systems whose configuration space is represented by a trivial fiber bundle. We describe how to generate gaits in the base space of the fiber bundle, or the shape space of the robot on which we assume full control. Such gaits are guaranteed to generate a non-zero motion along the fiber space, i.e., a net change in the position of the robot, while making sure that the robot’s shape is unchanged after a complete cycle. The gait generation technique presented in this paper is intuitive; it involves dividing the base space into well defined regions and devising a set of simple rules on how to generate curves in such regions. Not only do such curves guarantee non-zero position change but also do allow for gait optimization. I

TITLE Generalized Motion Planning for Underactuated Mechanical Systems Presented By

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Motion planning for dynamic variable inertia mechanical systems with non-holonomic constraints

Abstract: In this paper, we address a particular flavor of the motion planning problem, that is, the gait generation problem for underactuated variable inertia mechanical systems. Additionally, we analyze a rather general type of mechanical systems which we refer to as mixed systems. What is unique about this type of mechanical system is that both non-holonomic velocity constraints as well as instantaneous conservation of the generalized momentum variables defined along the allowable motion direction completely specify the systems velocity. By analyzing this general type of mechanical systems, we lay the grounds for a general and intuitive analysis of the gait generation problem. Through our approach, we provide a novel framework not only for classifying different types of mechanical systems, but also for identifying a partition on the space of allowable gaits. By applying our techniques to mixed systems which according to our classification are the most general type of mechanical systems, we verify the generality and applicability of our approach. Moreover, mixed systems yield the richest family of allowable gaits, hence, superseding the gait generation problem for other simpler types of mechanical systems. Finally, we apply our analysis to a novel mechanical system, the variable inertia snakeboard, which is a generalization of the original snakeboard that was previously studied in the literature.

Machine Theory

robot