Keep Rollin' - Whole-Body Motion Control and Planning for Wheeled Quadrupedal Robots

We show dynamic locomotion strategies for wheeled quadrupedal robots, which combine the advantages of both walking and driving. The developed optimization framework tightly integrates the additional degrees of freedom introduced by the wheels. Our approach relies on a zero-moment point based motion optimization which continuously updates reference trajectories. The reference motions are tracked by a hierarchical whole-body controller which computes optimal generalized accelerations and contact forces by solving a sequence of prioritized tasks including the nonholonomic rolling constraints. Our approach has been tested on ANYmal, a quadrupedal robot that is fully torque-controlled including the non-steerable wheels attached to its legs. We conducted experiments on flat and inclined terrains as well as over steps, whereby we show that integrating the wheels into the motion control and planning framework results in intuitive motion trajectories, which enable more robust and dynamic locomotion compared to other wheeled-legged robots. Moreover, with a speed of 4 m/s and a reduction of the cost of transport by 83 % we prove the superiority of wheeled-legged robots compared to their legged counterparts.Comment: IEEE Robotics and Automation Letter

Morphological and transcriptional effects of crude oil and dispersant exposure on the marine sponge Cinachyrella alloclada

Marine sponges play important roles in benthic ecosystems. More than providing shelter and food to other species, they help maintain water quality by regulating nitrogen and ammonium levels in the water, and bioaccumulate heavy metals. This system, however, is particularly sensitive to sudden environmental changes including catastrophic pollution event such as oil spills. Hundreds of oil platforms are currently actively extracting oil and gas in the Gulf of Mexico. To test the vulnerability of the benthic ecosystems to oil spills, we utilized the Caribbean reef sponge, Cinachyrella alloclada, as a novel experimental indicator. We have exposed organisms to crude oil and oil dispersant for up to 24 h and measured resultant gene expression changes. Our findings indicate that 1-hour exposure to water accommodated fractions (WAF) was enough to elicit massive shifts in gene expression in sponges and host bacterial communities (8052 differentially expressed transcripts) with the up-regulation of stress related pathways, cancer related pathways, and cell integrity pathways. Genes that were upregulated included heat shock proteins, apoptosis, oncogenes (Rab/Ras, Src, CMYC), and several E3 ubiquitin ligases. 24-hour exposure of chemically enhanced WAF (CE-WAF) had the greatest impact to benthic communities, resulting in mostly downregulation of gene expression (4248 differentially expressed transcripts). Gene deregulation from 1-hour treatments follow this decreasing trend of toxicity: WAF \u3e CE-WAF \u3e Dispersant, while the 24-hour treatment showed a shift to CE-WAF \u3e Dispersant \u3e WAF in our experiments. Thus, this study supports the development of Cinachyrella alloclada as a research model organism and bioindicator species for Florida reefs and underscores the importance of developing more efficient and safer ways to remove oil in the event of a spill catastrophe

How to manage gait and balance disorders among older adults aged 65 years and older with mild to moderate dementia in clinical practice?

Gait and balance disorders are frequent in demented older adults. Their management (i.e., diagnosis, assessment and treatment) is challenging in daily practice because of numerous evaluation tests available, difficulties to select the most adapted intervention, and the lack of knowledge of physicians and health professionals concerning adapted centers to refer their patients to those patients. Thus, a working group of experts was organized by the Gerontopole of Pays de Loire, France, in December 2010 with the aim to provide clinical guidelines for the management of older adults aged 65 years and older with mild to moderate dementia with gait and balance disorders. These guidelines provide answers to the following questions: 1) Is there gait and/or balance disorders? 2) Which specific tests used? and 3) How to treat patients

Holo-Transcriptome Sequences from the Tropical Marine Sponge Cinachyrella alloclada

Marine sponge transcriptomes are underrepresented in current databases. Furthermore, only two sponge genomes are available for comparative studies. Here we present the assembled and annotated holo-transcriptome of the common Florida reef sponge from the species Cinachyrella alloclada. After Illumina high throughput sequencing, the data assembled using Trinity v2.5 confirmed a highly symbiotic organism, with the complexity of high microbial abundance (HMA) sponges. This dataset is enriched in poly-A selected eukaryotic, rather than microbial transcripts. Overall, 39,813 transcripts with verified sponge sequence homology coded for 8,496 unique proteins. The average sequence length was found to be 946 bp with an N50 sequence length of 1290 bp. Overall, the sponge assembly resulted in a GC content of 51.04%, which is within the range of GC bases in a eukaryotic transcriptome. BUSCO scored completeness analysis revealed a completeness of 60.3% and 60.1% based on the Eukaryota and Metazoa databases, respectively. Overall, this study points to an overarching goal of developing the Cinachyrella alloclada sponge as a useful new experimental model organism

New perspectives for multicore architectures using advanced technologies

International audienceImpact of advanced technologies on the design and structure of multicore architectures is presented in this paper. More specifically, the power consumption and design complexity walls are examined leading to a “conquer-and-divide” strategy based on multicore partitioning and specialization. We then show how 3D stacking, Monolithic 3D integration and BEOL NVM can be associated to build new, simplified and power- efficient multicore

A fine grain variation-aware dynamic Vdd-hopping AVFS architecture on a 32nm GALS MPSoC

Conference of 39th European Solid-State Circuits Conference, ESSCIRC 2013 ; Conference Date: 16 September 2013 Through 20 September 2013; Conference Code:101630International audienceIn order to optimize global energy efficiency in the context of dynamic Process-Voltage-Temperature variations in advanced nodes, a fine-grain Adaptive Voltage and Frequency Scaling architecture is proposed and implemented on a 32 nm GALS Multi-Processor SoC. Each Processing Element is an independent Voltage-Frequency island and shows up to 18.2% energy gains due to local adaptability. Compared to a worst case approach, our proposal also allows a frequency boosting around 25% for a total area overhead of 10% including local frequency/voltage actuators, sensors and digital controller

Material and integration challenges for large scale Si quantum computing

International audienceSi spin qubits are very promising to enable large scale quantum computing as they are fast, of high quality and small. However, they are still lagging behind in terms of number of qubits. Indeed there are material and integration challenges to be tackled before fully expressing their potential

Carbon-sulfur bond-forming reaction catalysed by the radical SAM enzyme HydE.

International audienceCarbon-sulfur bond formation at aliphatic positions is a challenging reaction that is performed efficiently by radical S-adenosyl-L-methionine (SAM) enzymes. Here we report that 1,3-thiazolidines can act as ligands and substrates for the radical SAM enzyme HydE, which is involved in the assembly of the active site of [FeFe]-hydrogenase. Using X-ray crystallography, in vitro assays and NMR spectroscopy we identified a radical-based reaction mechanism that is best described as the formation of a C-centred radical that concomitantly attacks the sulfur atom of a thioether. To the best of our knowledge, this is the first example of a radical SAM enzyme that reacts directly on a sulfur atom instead of abstracting a hydrogen atom. Using theoretical calculations based on our high-resolution structures we followed the evolution of the electronic structure from SAM through to the formation of S-adenosyl-L-cysteine. Our results suggest that, at least in this case, the widely proposed and highly reactive 5'-deoxyadenosyl radical species that triggers the reaction in radical SAM enzymes is not an isolable intermediate

Variational Methods for Normal Integration

The need for an efficient method of integration of a dense normal field is inspired by several computer vision tasks, such as shape-from-shading, pho-tometric stereo, deflectometry, etc. Inspired by edge-preserving methods from image processing, we study in this paper several variational approaches for normal integration , with a focus on non-rectangular domains, free boundary and depth discontinuities. We first introduce a new discretization for quadratic integration, which is designed to ensure both fast recovery and the ability to handle non-rectangular domains with a free boundary. Yet, with this solver, discontinuous surfaces can be handled only if the scene is first segmented into pieces without discontinuity. Hence, we then discuss several discontinuity-preserving strategies. Those inspired, respectively , by the Mumford-Shah segmentation method and by anisotropic diffusion, are shown to be the most effective for recovering discontinuities