Contributions to shared control and coordination of single and multiple robots

L’ensemble des travaux présentés dans cette habilitation traite de l'interface entre un d'un opérateur humain avec un ou plusieurs robots semi-autonomes aussi connu comme le problème du « contrôle partagé ».Le premier chapitre traite de la possibilité de fournir des repères visuels / vestibulaires à un opérateur humain pour la commande à distance de robots mobiles.Le second chapitre aborde le problème, plus classique, de la mise à disposition à l’opérateur d’indices visuels ou de retour haptique pour la commande d’un ou plusieurs robots mobiles (en particulier pour les drones quadri-rotors).Le troisième chapitre se concentre sur certains des défis algorithmiques rencontrés lors de l'élaboration de techniques de coordination multi-robots.Le quatrième chapitre introduit une nouvelle conception mécanique pour un drone quadrirotor sur-actionné avec pour objectif de pouvoir, à terme, avoir 6 degrés de liberté sur une plateforme quadrirotor classique (mais sous-actionné).Enfin, le cinquième chapitre présente une cadre général pour la vision active permettant, en optimisant les mouvements de la caméra, l’optimisation en ligne des performances (en terme de vitesse de convergence et de précision finale) de processus d’estimation « basés vision »

Visión por computador aplicado a manipulador paralelo de tipo planar 3-RRR para la manipulación de un objeto

En este trabajo se establecerá la implementación de un sistema de visión en un manipulador paralelo de articulaciones rotatorias, con el propósito de calcular las coordenadas cartesianas. Se utilizará una técnica de servo control visual denominada Eye-to-hand que permite observar el área del trabajo del manipulador paralelo, ubicando el actuador final, el maro de referencia y el objetivo a seguir. La cámara captura la imagen del objeto tomado. La imagen es procesada mediante algoritmos creados en el software Matlab extrayendo las características principales de las imágenes tomadas. Cada imagen se someterá a filtros gaussianos para la eliminación de ruido de las cámaras y a un descriptor SURF para estabilizar la imagen, una de referencia respecto a las tomadas por la cámara en intervalos de tiempo. En las imágenes procesadas de cada captura, se determinan las correspondencias entre las imágenes para obtener sus semejanzas utilizando el método RANSAC. Obteniendo el análisis de la semejanza de las imágenes. Luego de establecer la estabilización se procede a implementar el cálculo de la homografía que permitirá realizar el cálculo de las coordenadas en pixeles tomadas en la imagen, convertirlas en coordenadas reales. Al obtener todo el proceso se procede a aplicar el estimador y predictor filtro de Kalman para determinar la posición del objeto cuando el objetivo en qué dirección se desplaza, el cual se tiene resultado una coordenada donde esta es retroalimentada a la cinemática del manipulador paralelo de tipo planar 3-RRR, estableciendo el movimiento de la plataforma móvil hacia el objetivo. Inicialmente se realizando dos pasos: El primer paso fue realizar una trayectoria generada que se realizó en el manipulador sin la intervención del sistema de visión; el segundo lugar se genera la misma trayectoria donde el objetivo es manipulado y guiado con base en la trayectoria generada inicialmente..

Full-Body Torque-Level Non-linear Model Predictive Control for Aerial Manipulation

Non-linear model predictive control (nMPC) is a powerful approach to control complex robots (such as humanoids, quadrupeds, or unmanned aerial manipulators (UAMs)) as it brings important advantages over other existing techniques. The full-body dynamics, along with the prediction capability of the optimal control problem (OCP) solved at the core of the controller, allows to actuate the robot in line with its dynamics. This fact enhances the robot capabilities and allows, e.g., to perform intricate maneuvers at high dynamics while optimizing the amount of energy used. Despite the many similarities between humanoids or quadrupeds and UAMs, full-body torque-level nMPC has rarely been applied to UAMs. This paper provides a thorough description of how to use such techniques in the field of aerial manipulation. We give a detailed explanation of the different parts involved in the OCP, from the UAM dynamical model to the residuals in the cost function. We develop and compare three different nMPC controllers: Weighted MPC, Rail MPC, and Carrot MPC, which differ on the structure of their OCPs and on how these are updated at every time step. To validate the proposed framework, we present a wide variety of simulated case studies. First, we evaluate the trajectory generation problem, i.e., optimal control problems solved offline, involving different kinds of motions (e.g., aggressive maneuvers or contact locomotion) for different types of UAMs. Then, we assess the performance of the three nMPC controllers, i.e., closed-loop controllers solved online, through a variety of realistic simulations. For the benefit of the community, we have made available the source code related to this work.Comment: Submitted to Transactions on Robotics. 17 pages, 16 figure

Integrated Task and Motion Planning of Multi-Robot Manipulators in Industrial and Service Automation

Efficient coordination of several robot arms in order to carry out some given independent/cooperative tasks in a common workspace, avoiding collisions, is an appealing research problem that has been studied in different robotic fields, with industrial and service applications. Coordination of several robot arms in a shared environment is challenging because complexity of collision free path planning increases with the number of robots sharing the same workspace. Although research in different aspects of this problem such as task planning, motion planning and robot control has made great progress, the integration of these components is not well studied in the literature. This thesis focuses on integrating task and motion planning multi-robot-arm systems by introducing a practical and optimal interface layer for such systems. For a given set of speci fications and a sequence of tasks for a multi-arm system, the studied system design aims to automatically construct the necessary waypoints, the sequence of arms to be operated, and the algorithms required for the robots to reliably execute manipulation tasks. The contributions of the thesis are three-fold. First, an algorithm is introduced to integrate task and motion planning layers in order to achieve optimal and collision free task execution. Representation via shared space graph (SSG) is introduced to check whether two arms share certain parts of the workspace and to quantify cooperation of such arm pairs, which is essential in selection of arm sequence and scheduling of each arm in the sequence to perform a task or a sub-task. The introduced algorithm allows robots to autonomously reason about a structured environment, performs the sequence planning of robots to operate, and provides robots and objects path for each task to succeed a set of goals. Secondly, an integrated motion and task planning methodology is introduced for systems of multiple mobile and fixed base robot arms performing different tasks simultaneously in a shared workspace. We introduce concept of dynamic shared space graph (D-SSG) to continuously check whether two arms sharing certain parts of the workspace at different time steps and quantify cooperation of such arm pairs, which is essential to the selection of arm sequences and scheduling of each arm in the sequence to perform a task or a sub-task. The introduced algorithm allows robots to autonomously reason about complex human involving environments to plan the high level decisions (sequence planning) of robots to operate and calculates robots and objects path for each task to succeed a set of goals. The third contribution is design of an integration algorithm between low-level motion planning and high-level symbolic task planning layers to produce alternate plans in case of kinematic and geometric changes in the environment to prevent failure in the high-level task plan. In order to verify the methodological contributions of the thesis with a solid implementation basis, some implementations and tests are presented in the open-source robotics planning environments ROS, Moveit and Gazebo. Detailed analysis of these implementations and test results are provided as well

Robot Manipulators

Robot manipulators are developing more in the direction of industrial robots than of human workers. Recently, the applications of robot manipulators are spreading their focus, for example Da Vinci as a medical robot, ASIMO as a humanoid robot and so on. There are many research topics within the field of robot manipulators, e.g. motion planning, cooperation with a human, and fusion with external sensors like vision, haptic and force, etc. Moreover, these include both technical problems in the industry and theoretical problems in the academic fields. This book is a collection of papers presenting the latest research issues from around the world