Retour au site du LAAS-CNRS

Laboratoire d’analyse et d’architecture des systèmes
Choisir la langue : FR | EN

485documents trouvés

17046
31/05/2017

Adaptive closed-loop speed control of BLDC motors with applications to multi-rotor aerial vehicles

A.FRANCHI, A.MALLET

RIS, IDEA

Manifestation avec acte : IEEE International Conference on Robotics and Automation ( ICRA ) 2017 du 29 mai au 03 juin 2017, Singapour (Singapour), Mai 2017, 6p. , N° 17046

Lien : https://hal.laas.fr/hal-01476812

Diffusable

Plus d'informations

Abstract

This paper introduces the adaptive bias and adaptive gain (ABAG) algorithm for closed-loop electronic speed control (ESC) of the brushless direct current (BLDC) motors typically used to spin the propellers in multi-rotor aerial robots. The ABAG algorithm is adaptive and robust in the sense that it does not require the knowledge of any mechanical/electrical parameter of the motor/propeller group and that neither a pre-calibration nor the knowledge of the feedforward/nominal input is needed. The ABAG algorithm is amenable to an extremely low complexity implementation. We experimentally prove that it can run in 27.5 µs on a 8 MHz microcontroller with no floating point unit and limited arithmetic capabilities allowing only 8-bit additions, subtractions and multiplications. Besides the controller implementation we present a self-contained open source software architecture that handles the entire speed control process, including clock synchronization, and over-current and blockage safeties. The excellent performance and robustness of ABAG are shown by experimental tests and aerial physical interaction experiments.

139881
16256
31/05/2017

Manipulation planning: building paths on constrained manifolds

J.MIRABEL, F.LAMIRAUX

GEPETTO

Manifestation avec acte : IEEE International Conference on Robotics and Automation ( ICRA ) 2017 du 29 mai au 03 juin 2017, Singapour (Singapour), Mai 2017, 16p. , N° 16256

Lien : https://hal.archives-ouvertes.fr/hal-01360409

Diffusable

Plus d'informations

Abstract

Constrained motion planning and Manipulation planning, for generic non-linear constraints, highly rely on the ability of solving non-linear equations. The Newton-Raphson method is often used in this context. This work tackles the problem of continuity that arises when projecting paths point wise with such method. A theoretical proof of an interval of continuity for the Newton-Raphson iteration function is given. This interval requires to bound from above the norm of the Hessian of the constraints. A method to compute this bound for constraints involving joint positions and orientations is proposed. Then, this theoretical result is used in two path projection algorithm to give a certicate of continuity of the continuously projected path. Finally, simulations are run on several problems.

139882
17037
29/05/2017

Towards robotic MAGMaS: multiple aerial-ground manipulator systems

N.STAUB, M.MOHAMMADI, D.BICEGO, D.PRATTICHIZZO, A.FRANCHI

RIS, IIT, Genova

Manifestation avec acte : IEEE International Conference on Robotics and Automation ( ICRA ) 2017 du 29 mai au 03 juin 2017, Singapour (Singapour), Mai 2017, 6p. , N° 17037

Lien : https://hal.laas.fr/hal-01476813

Diffusable

Plus d'informations

Abstract

In this paper we lay the foundation of the first heterogeneous multi-robot system of the Multiple Aerial-Ground Manipulator System (MAGMaS) type. A MAGMaS consists of a ground manipulator and a team of aerial robots equipped with a simple gripper manipulator the same object. The idea is to benefit from the advantages of both kinds of platforms, i.e., physical strength versus large workspace. The dynamic model of such robotic systems is derived, and its characteristic structure exhibited. Based on the dynamical structure of the system a nonlinear control scheme, augmented with a disturbance observer is proposed to perform trajectory tracking tasks in presence of model inaccuracies and external disturbances. The system redundancy is exploited by solving an optimal force/torque allocation problem that takes into account the heterogeneous system constraints and maximizes the force manipulability ellipsoid. Simulation results validated the proposed control scheme for this novel heterogeneous robotic system. We finally present a prototypical mechanical design and preliminary experimental evaluation of a MAGMaS composed by a kuka LWR4 and quadrotor based aerial robot.

139261
17036
29/05/2017

6D physical interaction with a fully actuated aerial robot

M.RYLL, G.MUSCIO, F.PIERRI, E.CATALDI, G.ANTONELLI, F.CACCAVALE, A.FRANCHI

RIS, University of Basilicata, UNICAS

Manifestation avec acte : IEEE International Conference on Robotics and Automation ( ICRA ) 2017 du 29 mai au 03 juin 2017, Singapour (Singapour), Mai 2017, 6p. , N° 17036

Lien : https://hal.laas.fr/hal-01476814

Diffusable

Plus d'informations

Abstract

This paper presents the design, control, and experimental validation of a novel fully–actuated aerial robot for physically interactive tasks, named Tilt-Hex. We show how the Tilt-Hex, a tilted-propeller hexarotor, is able to control the full pose (position and orientation independently) using a geometric control, and to exert a full-wrench (force and torque independently) with a rigidly attached end-effector using an admittance control paradigm. An outer loop control governs the desired admittance behavior and an inner loop based on geometric control ensures pose tracking. The interaction forces are estimated by a momentum based observer. Control and observation are made possible by a precise control and measurement of the speed of each propeller. An extensive experimental campaign shows that the Tilt-Hex is able to outperform the classical underactuated multi-rotors in terms of stability, accuracy and dexterity and represents one of the best choice at date for tasks requiring aerial physical interaction.

139259
16250
29/05/2017

Manipulation planning: addressing the crossed foliation issue

J.MIRABEL, F.LAMIRAUX

GEPETTO

Manifestation avec acte : IEEE International Conference on Robotics and Automation ( ICRA ) 2017 du 29 mai au 03 juin 2017, Singapour (Singapour), Mai 2017, 6p. , N° 16250

Lien : https://hal.archives-ouvertes.fr/hal-01358767

Diffusable

Plus d'informations

Abstract

This paper deals with manipulation planning. First, we propose a new tool called the constraint graph to describe the various motion constraints relative to a manipulation planning problem. Then, we describe a problem arising for some manipulation planning problems called the crossed foliation issue. We propose a extension of RRT algorithm that explores the leaves of the foliations generated by motion constraints and that solves the crossed foliation problem. Finally, we show a wide variety of problem that our approach can solve.

139880
17039
29/05/2017

Dynamic decentralized control for protocentric aerial manipulators

M.TOGNON, B.YUKSEL, G.BUONDONNO, A.FRANCHI

RIS, MPI, Rome

Manifestation avec acte : IEEE International Conference on Robotics and Automation ( ICRA ) 2017 du 29 mai au 03 juin 2017, Singapour (Singapour), Mai 2017, 6p. , N° 17039

Lien : https://hal.laas.fr/hal-01476817

Diffusable

Plus d'informations

Abstract

We present a control methodology for underactuated aerial manipulators that is both easy to implement on real systems and able to achieve highly dynamic behaviors. The method is composed by two parts: i) a nominal input/state trajectory generator that takes into account the full-body dynamics of the system exploiting its differential flatness property; ii) a decentralized feedback controller acting on the actuated degrees of freedom that confers the needed robustness to the closed-loop system. We demonstrate that the proposed controller is able to precisely track dynamic trajectories when implemented on a standard hardware. Comparative experiments clearly show the benefit of using the nominal input/state generator.

139275
17038
29/05/2017

Control of statically hoverable multi-rotor aerial vehicles and application to rotor-failure robustness for hexarotors

G.MICHIELETTO, M.RYLL, A.FRANCHI

RIS

Manifestation avec acte : IEEE International Conference on Robotics and Automation ( ICRA ) 2017 du 29 mai au 03 juin 2017, Singapour (Singapour), Mai 2017, 6p. , N° 17038

Lien : https://hal.laas.fr/hal-01476816

Diffusable

Plus d'informations

Abstract

Standard hexarotors are often mistakenly considered 'by definition' fail-safe multi-rotor platforms because of the two additional propellers when compared to quadrotors. However this is not true, in fact, a standard hexarotor cannot statically hover with 'only' five propellers. In this paper we provide a set of new general algebraic conditions to ensure static hover for any multi-rotor platform with any number of generically oriented rotors. These are elegantly formulated as the full-rankness of the control moment input matrix, and the non-orthogonality between its null-space and the row space of the control force input matrix. Input saturations and safety margins are also taken into account with an additional condition on the null-space of control moment input matrix. A deep analysis on the hoverability properties is then carried out focusing on the propeller loss in a hexarotor platform. Leveraging our general results we explain why a standard hexarotor is not robust and how it can be made robust thanks to a particular tilt of the rotors. We finally propose a novel cascaded controller based on a preferential direction in the null-space of the control moment input matrix for the large class of statically hoverable multi-rotors, which goes far beyond standard platforms, and we apply this controller to the case of failed tilted hexarotor.

139273
17129
24/05/2017

Implementation on a harvesting robot of a sensor-based controller performing a u-turn

E.LE FLECHER, A.DURAND PETITEVILLE, V.CADENAT, T.SENTENAC, S.VOUGIOUKAS

RAP, Univ. of California, Davis

Manifestation avec acte : International Workshop IEEE Electronics, Control, Measurement, Signals and their application to Mechatronics ( ECMSM ) 2017 du 24 mai au 26 mai 2017, Saint Sébastien (Espagne), Mai 2017, pp.223-228 , N° 17129

Diffusable

Plus d'informations

Abstract

In this paper we investigate the navigation of a harvesting robot using sensor-based controllers in an orchard. More precisely, we focus our work on the particular u-turn maneuver which allows the mechanical system to move from the current row to the next one. By using sensor-based controllers, the control law is expressed in the sensor space, and the robot does not have to localize itself nor use a global map of the field. The navigation task can then be realized more accurately. This paper reports the implementation of two generic sensorbased controllers. These controllers allow a differential robot to follow spirals around a given point of interest. In this work, we adapt these two controllers to our specific robot (car-like system), before detailing the ROS implementation architecture. Both simulations and experimental results show the interest and the efficiency of our controllers to perform u-turns in an orchard

139877
17130
24/05/2017

A finite state machine modeling language and the associated tools allowing fast prototyping for FPGA devices

B.VANDEPORTAELE

RIS

Manifestation avec acte : International Workshop IEEE Electronics, Control, Measurement, Signals and their application to Mechatronics ( ECMSM ) 2017 du 24 mai au 26 mai 2017, Saint Sébastien (Espagne), Mai 2017, pp.253-258 , N° 17130

Diffusable

Plus d'informations

Abstract

The VHDL hardware description language is commonly used to describe Finite State Machine(FSM) models to be implemented on Field Programmable Gate Array(FPGA) devices. However, its versatility permits to describe behaviors that deviate from a true FSM leading to systems that are complex to prove, to document and to maintain. The purpose of this work is to propose a language and the associated tools to create FSMs through a dedicated and intuitive textual description. This language is inspired by the dot language used in Graphviz, a tool to define graphs, and adds all the necessary elements required to describe complex FSM models (using for instance memorized or non memorized actions and actions on states or transitions). Moreover some additional elements are proposed to enrich the standard FSM model such as the genericity that permits to define simultaneously multiple states, transitions or actions using a generative description. A multi-platform open source JAVA program named FSMProcess [1] is introduced. Based on the ANTLR parser generator, it achieves the automatic generation of all the required .vhdl files (component, package, instantiation example and testbench) and a .dot file that is used to generate an always up-to-date graphical representation of the model (hence its documentation). This tool also supports simple model checking and integration of additional VHDL code. It can be used conjointly with version control systems and is coupled with the open source GHDL simulator to allow fast prototyping. It can be used either with its Graphical User Interface either as a command line compiler for integration in makefiles.

139879
17123
19/05/2017

Champs de tenseurs. Bases mobiles et naturelles. Torsions. Courbures

M.RENAUD

RAP

Rapport LAAS N°17123, Mai 2017, 199p.

Diffusable

139812
Les informations recueillies font l’objet d’un traitement informatique destiné à des statistiques d'utilisation du formulaire de recherche dans la base de données des publications scientifiques. Les destinataires des données sont : le service de documentation du LAAS.Conformément à la loi « informatique et libertés » du 6 janvier 1978 modifiée en 2004, vous bénéficiez d’un droit d’accès et de rectification aux informations qui vous concernent, que vous pouvez exercer en vous adressant à
Pour recevoir une copie des documents, contacter doc@laas.fr en mentionnant le n° de rapport LAAS et votre adresse postale. Signalez tout problème de dysfonctionnement à sysadmin@laas.fr. http://www.laas.fr/pulman/pulman-isens/web/app.php/