Reducing the Barrier to Entry of Complex Robotic Software: a MoveIt! Case Study

Developing robot agnostic software frameworks involves synthesizing the disparate fields of robotic theory and software engineering while simultaneously accounting for a large variability in hardware designs and control paradigms. As the capabilities of robotic software frameworks increase, the setup difficulty and learning curve for new users also increase. If the entry barriers for configuring and using the software on robots is too high, even the most powerful of frameworks are useless. A growing need exists in robotic software engineering to aid users in getting started with, and customizing, the software framework as necessary for particular robotic applications. In this paper a case study is presented for the best practices found for lowering the barrier of entry in the MoveIt! framework, an open-source tool for mobile manipulation in ROS, that allows users to 1) quickly get basic motion planning functionality with minimal initial setup, 2) automate its configuration and optimization, and 3) easily customize its components. A graphical interface that assists the user in configuring MoveIt! is the cornerstone of our approach, coupled with the use of an existing standardized robot model for input, automatically generated robot-specific configuration files, and a plugin-based architecture for extensibility. These best practices are summarized into a set of barrier to entry design principles applicable to other robotic software. The approaches for lowering the entry barrier are evaluated by usage statistics, a user survey, and compared against our design objectives for their effectiveness to users

Solutions TP10 - Contact hertzien

Ce chapitre est composé par les solutions des problèmes proposés. Il s'agit des exercices sur le contact hertzien entre deux pièces

Full-wave simulations of electromagnetic cloaking structures

Based on a coordinate transformation approach, Pendry {\it et al.} have reported electromagnetically anisotropic and inhomogeneous shells that, in theory, completely shield an interior structure of arbitrary size from electromagnetic fields without perturbing the external fields. We report full-wave simulations of the cylindrical version of this cloaking structure using ideal and nonideal (but physically realizable) electromagnetic parameters in an effort to understand the challenges of realizing such a structure in practice. The simulations indicate that the performance of the electromagnetic cloaking structure is not especially sensitive to modest permittivity and permeability variations. This is in contrast to other applications of engineered electromagnetic materials, such as subwavelength focusing using negative refractive index materials. The cloaking performance degrades smoothly with increasing loss, and effective low-reflection shielding can be achieved with a cylindrical shell composed of an eight (homogeneous) layer approximation of the ideal continuous medium

TP2 - Ajustements

Dans ce chapitre, on présente quelques exercices sur les ajustements. Avec ces exemples, les étudiants vont apprendre la nomenclature spécifique, comment trouver les écarts, le jeu et l'interférence dans un ajustement

Localized magnetic states in Rashba dots

We study the formation of local moments in quantum dots arising in quasi-one dimensional electron wires due to localized spin-orbit (Rashba) interaction. Using an Anderson-like model to describe the occurrence of the magnetic moments in these Rashba dots, we calculate the local magnetization within the mean-field approximation. We find that the magnetization becomes a nontrivial function of the Rashba coupling strength. We discuss both the equilibrium and nonequilibrium cases. Interestingly, we obtain a magnetic phase which is stable at large bias due to the Rashba interaction.Comment: 8 pages, 4 figures; to appear in Phys. Rev.

Numerical Experiment to Analyse the Reliability of Coarse Grid Based Numerical Methods for Modelling Groundwater Flow by Drainage Objects Like Wells in Confined Aquifer

AbstractAt the neighbourhood of several drainage objects types in shallow aquifer like fully penetrated wells, partially penetrated wells, well with laterals, horizontal drainages etc. groundwater flow forms contain frequently 2D/3D singular behaviours (e.g. logarithmical or polar singularities), which require special attention by coarse grid simulations Groundwater reservoir modelling. The first objective of the paper is to test the accuracy of Finite Volume Methods with specific reference to one of the most used standard reservoir modelling software in groundwater modelling PMWIN/MODFLOW (i.e. Processing MODFLOW for Window), Chiang (2001). The numerical experiment will be accomplished mainly for fully penetrating well (W) and partially penetrating well (ppW) using various discretization size.It will be shown that the standard Well Index method (Peaceman 1983), currently used by coarse grid simulations, allows the local correction in well blocks only for hydraulic head (or pressure) in the wellbore obtained by coarse grid simulation for imposed global discharge/recharge rate of the well. In the paper an extension of the WI based method will be proposed which allows also the well discharge rate correction by coarse grid modelling for imposed hydraulic head (imposed pressure) in the well. The proposed method is proved with several numerical simulation examples for fully wells and ppWells