2014 IEEE International Conference on Robotics and Automation (ICRA)

OpenGV is a new C++ library for calibrated realtime 3D geometric vision. It unifies both central and non-central absolute and relative camera pose computation algorithms within a single library. Each problem type comes with minimal and non-minimal closed-form solvers, as well as non-linear iterative optimization and robust sample consensus methods. OpenGV therefore contains an unprecedented level ... View full abstract»

Unlike the traditional feature-based methods, we propose using motion vectors (MVs) from video streams as inputs for visual navigation. Although MVs are very noisy and with low spatial resolution, MVs do possess high temporal resolution which means it is possible to merge MVs from different frames to improve signal quality. Homography filtering and MV thresholding are proposed to further improve M... View full abstract»

We propose a semi-direct monocular visual odometry algorithm that is precise, robust, and faster than current state-of-the-art methods. The semi-direct approach eliminates the need of costly feature extraction and robust matching techniques for motion estimation. Our algorithm operates directly on pixel intensities, which results in subpixel precision at high frame-rates. A probabilistic mapping m... View full abstract»

In this paper, we tackle the problem of mapping multiple 3D rigid structures and estimating their motions from perspective views through a car-mounted camera. The proposed method complements conventional localization and mapping algorithms (such as Visual Odometry and SLAM) to estimate motions of other moving objects in addition to the vehicle's motion. We present a theoretical framework for robus... View full abstract»

This article presents an approach and a systematic design methodology to path following control based on motion decoupling for high-performance ducted fan unmanned aerial vehicles (UAVs). The decoupling is performed according to the principle of regarding the attitude motion as a virtual input of the lateral longitudinal flight dynamics. This allows the attitude and flight controllers to be design... View full abstract»

Inspired by the agility of flying insects and the recent development on an insect-scale aerial vehicle, we propose a single-loop adaptive flight control suite designed with an emphasis on the ability to track dynamic trajectories as a step towards the goal of performing acrobatic maneuvers as observed in real insects. Instead of the conventional approach of having cascaded control loops, the propo... View full abstract»

This paper presents periodic solutions for a quadrocopter maintaining a height around a position in space despite having lost a single, two opposing, or three propellers. In each case the control strategy consists of the quadrocopter spinning about a primary axis, fixed with respect to the vehicle, and tilting this axis for translational control. A linear, timeinvariant description of deviations f... View full abstract»

The challenge of aerial robotic physical interaction towards inspection of infrastructure facilities through contact is the main motivation of this paper. A hybrid model predictive control framework is proposed, based on which a typical quadrotor vehicle becomes capable of stable physical interaction, accurate trajectory tracking on environmental surfaces as well as force control with only minor s... View full abstract»

On typical multi-robot teams, there is an implicit assumption that robots can be trusted to effectively perform assigned tasks. The multi-robot patrolling task is an example of a domain that is particularly sensitive to reliability and performance of robots. Yet reliable performance of team members may not always be a valid assumption even within homogeneous teams. For instance, a robot's performa... View full abstract»

We study robotic tracking of dynamic plume front modeled by the advection-diffusion equation in this paper. Different from existing work purely relying on gradient measurement, the transport model of pollution source is explicitly considered in tracking control design. We first study the problem using a single robot and solve the problem in an estimation and control framework. We then extend it to... View full abstract»

We present a novel analytical approach to computing the population and geometric parameters of a multi-robot system that will provably produce specified boundary coverage statistics. We consider scenarios in which robots with no global position information, communication, or prior environmental data have arrived at uniformly random locations along a simple closed or open boundary. This type of sce... View full abstract»

In the context of robotics coverage describes the deployment of mobile sensors or agents in a target area. This paper presents a new solution to coverage in nonconvex environments. We apply a modification to the coverage approach in (Cortes, et.al., 2004), making use of visibility sets and a contraction of the environment, leading to a change in the bounds of integration. The resulting feedback co... View full abstract»

Motion planning is a difficult and widely studied problem in robotics. Current research aims not only to find feasible paths, but to ensure paths have certain properties, e.g., shortest or safest paths. This is difficult for current state-of-the-art sampling-based techniques as they typically focus on simply finding any path. Despite this difficulty, sampling-based techniques have shown great succ... View full abstract»

We propose a new method of representing de-formable objects that allows both physical and qualitative properties to be captured in an efficient representation. We show how to use this representation with two types of motion planners: 1) optimal discrete planners, which are suitable for low-dimensional problems, 2) sampling-based planners that plan in high-dimensional cost spaces. In both cases, ou... View full abstract»

Analytical results describing the optimal trajectories for general classes of robot systems have proven elusive, in part because the optimal trajectories for a complex system may not exist, or may be computed only numerically from differential equations. This paper studies a simpler optimization problem: finding an optimal sequence and optimal durations of motion primitives (simple preprogrammed a... View full abstract»

Motion planning is an important problem with many applications in robotics. In this paper, we focus on motion planning with rectangular obstacles parallel to the X, Y or Z axis. We formulate motion planning using Satisfiability Modulo Theories (SMT) and use SMT solvers to find a feasible path from the source to the goal. Our formulation decompose the robotic path into N path segments where the two... View full abstract»

A wearable robot secured on the shoulder of a human is developed for assisting its wearer in the execution of tasks in the overhead workspace. Installing a ceiling panel is an example of such a task. During this task the robot can hold the panel or collaborate actively with the human in order to fix the panel with the appropriate equipment. This wearable robot, termed "Supernumerary Robotic Limbs"... View full abstract»

This paper presents a study of end-point impedance measurement at human hand, with professional and novice manual welders when they are performing Tungsten Inert Gas (TIG) welding interactively with the KUKA Light Weight Robot Arm (LWR). The welding torch is attached to the KUKA LWR, which is admittance controlled via a force sensor to give the feeling of a free floating mass at its end-effector. ... View full abstract»

A control algorithm based on admittance regulation is proposed for human-robot cooperative force amplification. The controller is particularly suitable for physical interaction in both free space and constrained motions thanks to an active transition between the two modes. It is also able to cancel possible high frequency oscillations due to the contact with the environment. A mathematical analysi... View full abstract»

A new approach to physically assisting the human with a wearable robot is presented. Supernumerary Robotic Limbs (SRLs) attached to the human waist support the body efficiently when the human is taking fatiguing postures, e.g. hunching over, squatting, or reaching the ceiling. Unlike a leg exoskeleton, where powered joints are attached to the human joints and are constrained to move together with ... View full abstract»

Motion planning in belief space (under motion and sensing uncertainty) is a challenging problem due to the computational intractability of its exact solution. The Feedback-based Information RoadMap (FIRM) framework made an important theoretical step toward enabling roadmap-based planning in belief space and provided a computationally tractable version of belief space planning. However, there are s... View full abstract»

This paper presents an algorithm based on ecological models of foraging and that uses uncertainty in scientific observations made by the robot to value future actions. It is the hypothesis of this work that the foraging strategy will be an improvement over strategies based on principles from the design of experiments literature for small budget sizes. The experiment in this paper shows that for sm... View full abstract»

Finding objects in human environments requires autonomous mobile robots to reason about potential object locations and to plan to perceive them accordingly. By using information about the 3D structure of the environment, knowledge about landmark objects and their spatial relationship to the sought object, search can be improved by directing the robot towards the most likely object locations. In th... View full abstract»

Searching for objects in occluded spaces is one of the problems robots need to solve when tackling mobile manipulation tasks. Most approaches focus only on searching for a specific object. In this paper, we use the concept of relational affordances to improve occluded object search performance. Affordances define action possibilities on an object in the environment and play a role in basic cogniti... View full abstract»

The use of redundant sensors brings a rich diversity of information, nevertheless fusing different sensors that run at vastly different frequencies into a proper estimate is still a challenging sensor fusion problem. Instead of using the size-varying measurements and thereby the size-varying filters during each sampling period, we propose to find a substitute of the unavailable low frequency measu... View full abstract»