Browsing by Author "Bernardino, A."
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- A large area TOF-tracker device based on multi-gap Resistive Plate ChambersPublication . Assis, P.; Bernardino, A.; Blanco, A.; Luz, R.; Mendes, L.; Michel, J.; Neiser, A.; Pereira, A.; Pimenta, M.; Shellard, R.; Traxler, M.; Clemêncio, Filomena; Carolino, N.; Cunha, O.; Ferreira, M.; Fonte, P.; Lopes, L.; Loureiro, C.The TOF-tracker concept, the simultaneous measurement of accurate time and bi-dimensional space coordinates in a single gaseous detector, has been previously demonstrated. The detector yielded a time resolution of 77 ps σ along with a bi-dimensional position resolution of 38 μm σ over a full active area of 60 × 60 mm2. In here, we report about a large area, 1550 × 1250 mm2, TOF-tracker device, tested by tracking cosmic muons, yielding a position resolution down to 1.33 mm σ, a simultaneous time resolution of 150 ps σ and 92% detection efficiency, over the entire area of the detector. The sub-millimetre electronic resolution of the readout chain suggests that the position resolution here reported could be dominated by non-corrected systematic effects and therefore it could be yet significantly improved.
- Probabilistic Egomotion for Stereo Visual OdometryPublication . Silva, Hugo; Bernardino, A.; Silva, EduardoWe present a novel approach of Stereo Visual Odometry for vehicles equipped with calibrated stereo cameras. We combine a dense probabilistic 5D egomotion estimation method with a sparse keypoint based stereo approach to provide high quality estimates of vehicle’s angular and linear velocities. To validate our approach, we perform two sets of experiments with a well known benchmarking dataset. First, we assess the quality of the raw velocity estimates in comparison to classical pose estimation algorithms. Second, we added to our method’s instantaneous velocity estimates a Kalman Filter and compare its performance with a well known open source stereo Visual Odometry library. The presented results compare favorably with state-of-the-art approaches, mainly in the estimation of the angular velocities, where significant improvements are achieved.
- Probabilistic Stereo Egomotion TransformPublication . Silva, Hugo; Bernardino, A.; Silva, EduardoIn this paper we propose a novel fully probabilistic solution to the stereo egomotion estimation problem. We extend the notion of probabilistic correspondence to the stereo case which allow us to compute the whole 6D motion information in a probabilistic way. We compare the developed approach against other known state-of-the-art methods for stereo egomotion estimation, and the obtained results compare favorably both for the linear and angular velocities estimation.