Attitude Estimation and Control Using Linear-Like Complementary Filters: Theory and Experiment

This paper proposes new algorithms for attitude estimation and control based on fused inertial vector measurements using linear complementary filters principle. First, n-order direct and passive complementary filters combined with TRIAD algorithm are proposed to give attitude estimation solutions. These solutions which are efficient with respect to noise include the gyro bias estimation. Thereafter, the same principle of data fusion is used to address the problem of attitude tracking based on inertial vector measurements. Thus, instead of using noisy raw measurements in the control law a new solution of control that includes a linear-like complementary filter to deal with the noise is proposed. The stability analysis of the tracking error dynamics based on LaSalle's invariance theorem proved that almost all trajectories converge asymptotically to the desired equilibrium. Experimental results, obtained with DIY Quad equipped with the APM2.6 auto-pilot, show the effectiveness and the performance of the proposed solutions.Comment: Submitted for Journal publication on March 09, 2015. Partial results related to this work have been presented in IEEE-ROBIO-201

A case of repetitive myocardial infarction with unobstructed coronaries due to Churg-Strauss syndrome

© The Author(s) 2019. Published by Oxford University Press on behalf of the European Society of Cardiology.BackgroundMyocardial infarction is most commonly caused by thrombosis occurring on a background of coronary atherosclerosis, resulting in reduced coronary flow. Less often, myocardial infarction can occur in the absence of coronary disease. The pathomechanism of myocardial infarction in such patients is heterogeneous and more challenging to diagnose and treat. European Society of Cardiology published a position paper on myocardial infarction in patients with non-obstructive coronary disease, with definitions and recommendations for investigations, in what has hitherto been an under-recognized and under-investigated Cinderella-like condition. However, the importance of obtaining a diagnosis is all the more important, since one treatment approach with revascularization and antithrombotic treatment does not ‘fit all’.Case summaryA 70-year-old male patient presented with chest pain at rest, associated with rise in troponin and without ECG changes. A diagnosis of non-ST elevation myocardial infarction was made. Coronary angiography showed a smooth stenosis which resolved with administration of intracoronary nitrate. A diagnosis of coronary artery spasm was made, and treatment initiated. After 18 months, the patient had recurrent chest pains at rest, unresponsive to glyceryl trinitrate (GTN). Cardiac magnetic resonance revealed extension of subendocardial infarction, without inducible ischaemia. CT coronary angiogram (CTCA) showed non-obstructive coronaries. Blood tests showed significant eosinophilia, raised troponin, and C-reactive protein (CRP) that fluctuated without correlation with symptoms or any ECG changes. A diagnosis of Churg–Strauss syndrome was made, and immunosuppression commenced.DiscussionChurg–Strauss syndrome is an autoimmune vasculitis in patients with history of atopy or late-onset asthma which when involving coronary arteries can lead to myocardial injury mimicking acute coronary syndrome (ACS). Identification is important to allow initiation of immunosuppression which can prevent development or progression.Peer reviewedFinal Published versio

Une analyse cognitive de la perception de la coopération forme-mouvement dans les animations virtuelles

Session animation - http://www-lisic.univ-littoral.fr/afig2012/International audienceIn this work, we carried out psychocognitive experiments about the human cognitive behavior faced to a new generation of virtual animations. These animations are based on motion synthesized by means of physical modeling, and synthetic shapes mapped on the so produced movements. The novelty of these animations is that we associated two complementary kinds of figures: on one hand, the movement, as it is built using physical models, which presents realistic and coherent dynamics, and on the other hand, various non realistic shapes that are mapped on them. With this process, we created paradoxical and questioning animated pictures. Through the experiments, we are investigating the impact of these unusual animations on the human perception and cognition. This led to a first set of human's behavior observations and some first results on human cognition and perception faced to such new perceptive stimuli. Mainly, our approach is to experiment the creative perceptual posture of human subjects confronted to novel types of artistic animations

The Kinetics Observer: A Tightly Coupled Estimator for Legged Robots

In this paper, we propose the "Kinetics Observer", a novel estimator addressing the challenge of state estimation for legged robots using proprioceptive sensors (encoders, IMU and force/torque sensors). Based on a Multiplicative Extended Kalman Filter, the Kinetics Observer allows the real-time simultaneous estimation of contact and perturbation forces, and of the robot's kinematics, which are accurate enough to perform proprioceptive odometry. Thanks to a visco-elastic model of the contacts linking their kinematics to the ones of the centroid of the robot, the Kinetics Observer ensures a tight coupling between the whole-body kinematics and dynamics of the robot. This coupling entails a redundancy of the measurements that enhances the robustness and the accuracy of the estimation. This estimator was tested on two humanoid robots performing long distance walking on even terrain and non-coplanar multi-contact locomotion

Rapid Pose Label Generation through Sparse Representation of Unknown Objects

Deep Convolutional Neural Networks (CNNs) have been successfully deployed on robots for 6-DoF object pose estimation through visual perception. However, obtaining labeled data on a scale required for the supervised training of CNNs is a difficult task - exacerbated if the object is novel and a 3D model is unavailable. To this end, this work presents an approach for rapidly generating real-world, pose-annotated RGB-D data for unknown objects. Our method not only circumvents the need for a prior 3D object model (textured or otherwise) but also bypasses complicated setups of fiducial markers, turntables, and sensors. With the help of a human user, we first source minimalistic labelings of an ordered set of arbitrarily chosen keypoints over a set of RGB-D videos. Then, by solving an optimization problem, we combine these labels under a world frame to recover a sparse, keypoint-based representation of the object. The sparse representation leads to the development of a dense model and the pose labels for each image frame in the set of scenes. We show that the sparse model can also be efficiently used for scaling to a large number of new scenes. We demonstrate the practicality of the generated labeled dataset by training a pipeline for 6-DoF object pose estimation and a pixel-wise segmentation network

Synergy between optical and microwave remote sensing to derive soil and vegetation parameters from MAC Europe 1991 Experiment

The ability of remote sensing for monitoring vegetation density and soil moisture for agricultural applications is extensively studied. In optical bands, vegetation indices (NDVI, WDVI) in visible and near infrared reflectances are related to biophysical quantities as the leaf area index, the biomass. In active microwave bands, the quantitative assessment of crop parameters and soil moisture over agricultural areas by radar multiconfiguration algorithms remains prospective. Furthermore the main results are mostly validated on small test sites, but have still to be demonstrated in an operational way at a regional scale. In this study, a large data set of radar backscattering has been achieved at a regional scale on a French pilot watershed, the Orgeval, along two growing seasons in 1988 and 1989 (mainly wheat and corn). The radar backscattering was provided by the airborne scatterometer ERASME, designed at CRPE, (C and X bands and HH and VV polarizations). Empirical relationships to estimate water crop and soil moisture over wheat in CHH band under actual field conditions and at a watershed scale are investigated. Therefore, the algorithms developed in CHH band are applied for mapping the surface conditions over wheat fields using the AIRSAR and TMS images collected during the MAC EUROPE 1991 experiment. The synergy between optical and microwave bands is analyzed

Consanguinity and reproductive health among Arabs

Consanguineous marriages have been practiced since the early existence of modern humans. Until now consanguinity is widely practiced in several global communities with variable rates depending on religion, culture, and geography. Arab populations have a long tradition of consanguinity due to socio-cultural factors. Many Arab countries display some of the highest rates of consanguineous marriages in the world, and specifically first cousin marriages which may reach 25-30% of all marriages. In some countries like Qatar, Yemen, and UAE, consanguinity rates are increasing in the current generation. Research among Arabs and worldwide has indicated that consanguinity could have an effect on some reproductive health parameters such as postnatal mortality and rates of congenital malformations. The association of consanguinity with other reproductive health parameters, such as fertility and fetal wastage, is controversial. The main impact of consanguinity, however, is an increase in the rate of homozygotes for autosomal recessive genetic disorders. Worldwide, known dominant disorders are more numerous than known recessive disorders. However, data on genetic disorders in Arab populations as extracted from the Catalogue of Transmission Genetics in Arabs (CTGA) database indicate a relative abundance of recessive disorders in the region that is clearly associated with the practice of consanguinity