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This paper reports an algorithm for the registration of images with low overlap and low visual feature density—a typical characteristic of down-looking underwater imagery. Our algorithm exploits locally accurate temporal motion-priors and pairwise image correspondences to aggregate semi-rigid sets of sequential images. These sets are then used to search for visual correspondences across sets instead...
Estimating the relative pose and motion of cooperative satellites using on-board sensors is a challenging problem. When the satellites are non-cooperative, the problem becomes far more complicated, as there might be poor or no a priori information about the motion or structure of the target satellite. In this work we develop robust algorithms for solving the said problem by assuming that only visual...
Recently, many gait recognition algorithms are proposed, and the optimal camera arrangement is necessary to maximize the performance. In this paper, we propose the optimal camera arrangement by using a performance model that considers observation conditions comprehensively. We select silhouette resolution, observation view, and its local and global changes as the observation conditions affecting the...
Classical logics have already been proposed as a means to specify and implement access control systems. In this paper, we first show that some facets of access control render these logics inadequate. In particular, when used as an inference engine, they are insufficient for decision making on the basis of imperfect information, a situation that occurs frequently in new computing paradigms. In addition,...
In order to assist a surgeon while operating on a beating heart, visual stabilization makes the beating heart appear still by providing the current heart view as stationary and non-moving. In this way, the surgeon is not disturbed during an operation by the motion of the heart and has the impression of performing conventional surgery. In contrast to existing methods for visual stabilization, the proposed...
This article deals with the divergence of the Kalman filter when used on non-linear observation functions. The Kalman filter allows to update some parameters according to observations and their uncertainties. The observation model which links the parameters to the observations is often non-linear and has to be linearized. An improper linearization leads to a divergence effect that could be contained...
In this paper, a method for tracking (identifying) the fighter F117 is introduced. Because of its individual design and also the material that is used to build the fighter body, it cannot be identified and tracked with the conventional radars. In this work, an operational method based on image processing and by using LabView software is presented. By extraction the special geometrical properties of...
The effectiveness of directional sensors like video and IR cameras, and of directional effectors like acoustic devices and dazzlers, depends of course one's ability to aim the device onto its target. Aiming inaccuracies reduce the dwell time on a target and degrade expected performance. Aiming inaccuracies in turn depend on the velocity of the target, the sensor by which it is tracked (possibly human...
We present a stereo vision-aided inertial navigation system and demonstrate its potential in power line inspection at close range using an unmaned aerial vehicle. This is made possible by recent developments in visual odometry and a newly proposed algorithm for the loose coupling of an inertial measurement unit and visual odometry. Our experiments show promising results.
In this work we focus on the problem of probabilistic sensor fusion in Multi-Robot Multi-Sensor Systems (MRMS), taking into account that some sensors might fail or produce erroneous information. We study fusion methods that can successfully cope with situations of agreement, partial agreement, and disagreement between sensors. We define a set of specifications for fusion methods appropriate for MRMS...
A reliable estimation of heart surface motion is an important prerequisite for the synchronization of surgical instruments in robotic beating heart surgery. In general, only an imprecise description of the heart dynamics and measurement systems is available. This means that the estimation of heart motion is corrupted by stochastic and systematic uncertainties. Without consideration of these uncertainties,...
Vision based simultaneous localization and mapping (SLAM) has recently received much research interest. However, vision based SLAM could be corrupted with the inclusion of moving entities, which makes it hard to operate in dynamic environments. Simultaneous localization, mapping and moving object tracking (SLAMMOT) serves as a solution to deal with moving objects while performing SLAM. The existing...
Technology for multirobot systems has advanced to the point where we can consider their use in a variety of important domains, including urban search and rescue. A key to the practical usefulness of multirobot systems is the ability to have a large number of robots effectively controlled by small numbers of operators. In this paper, two modalities for controlling a team of 24 robots in a foraging...
This paper proposes a new framework for fast and reliable traffic sign detection using images obtained from a single front-facing road vehicle camera. Our focus is on a methodology for reducing the computational requirements and increasing the performance of existing detection methods by refining the image space search using 3D scene geometry. Information concerning physical traffic sign dimensions...
We combine a visual odometry system with an aided inertial navigation filter to produce a precise and robust navigation system that does not rely on external infrastructure. Incremental structure from motion with sparse bundle adjustment using a stereo camera provides real-time highly accurate pose estimates of the sensor which are combined with six degree-of-freedom inertial measurements in an Extended...
The ability to recognize objects and to localize them precisely is essential in all service robotic applications. One of the main challenges for service robots during operation lies in the handling of unavoidable uncertainties which originate from model and sensor inaccuracies and are characteristic for realistic application scenarios. Robustness under real world conditions can only be achieved when...
This work aims to promote integrity in autonomous perceptual systems, with a focus on outdoor unmanned ground vehicles equipped with a camera and a 2D laser range finder. A method to check for inconsistencies between the data provided by these two heterogeneous sensors is proposed and discussed. First, uncertainties in the estimated transformation between the laser and camera frames are evaluated...
Network robot systems (NRS) provide many scientific and technological challenges, given that robots interact with each other as well as with sensors present in the environment to accomplish certain tasks. In this work, we consider an essential problem in NRS, namely how to perform task planning given the limitations both in on-board sensing as well as in the environment's sensors. Partially observable...
A Compton camera is an imaging system for three-dimensional (3D) distribution of gamma emitting sources based on Compton scattering interaction. The measurement error on energies and positions directly leads to uncertainties on the formation of cones and degrades the spatial resolution of the reconstructed images. Mostly the limited energy resolution, Doppler broadening and position segmentation of...
The primary issue regarding the proliferation of radioactive materials is their possible ill-intentioned use. Depending on the material, it could enable the construction of dirty bombs or even nuclear devices. Several detection systems have been engineered to help control the transport of these materials and to provide efficient detection capabilities. Compton cameras have been used in fields such...
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