Section: New Software and Platforms


ALIAS, Algorithms Library of Interval Analysis for Systems

Participants : Hiparco Lins Vieira, Jean-Pierre Merlet [correspondant] , Yves Papegay.

URL: http://www-sop.inria.fr/hephaistos/developpements/main.html

The ALIAS library whose development started in 1998, is a collection of procedures based on interval analysis for systems solving and optimization.

ALIAS is made of two parts:

ALIAS-C++ : the C++ library (87 000 code lines) which is the core of the algorithms

ALIAS-Maple : the Maple interface for ALIAS-C++ (55 000 code lines). This interface allows one to specify a solving problem within Maple and get the results within the same Maple session. The role of this interface is not only to generate the C++ code automatically, but also to perform an analysis of the problem in order to improve the efficiency of the solver. Furthermore, a distributed implementation of the algorithms is available directly within the interface.

ALIAS is a core element for solving the usually complex equations we have to manage our robotics problems. We may mention as example our work on cable-driven parallel robot (see section 6.1.1) involves non-algebraic models whose exact solving is required while the unknowns of our system are physical entities that may usually be bounded (meaning that we are not interested in all solutions of the system but only in the one that make physical sense) and therefore interval analysis is appropriate (and quite often the only one that may manage to get exactly all solutions). This year we have also used ALIAS to provide certified solutions of the kinematics of a flexible parallel robots  [17]. We have confirmed the solutions that has been provided by a computer intensive iterative methods and have shown that the interval analysis method was able to manage a more complex case for which the iterative method cannot be reasonably used. In a third example we combine interval analysis and Monte-Carlo method for developing a reliable motion planning for parallel manipulators [15] while interval analysis has been used for the design of parallel robot [14].

Hardware platforms

We describe here only the new platforms that have been developed or improved in 2019 while we maintain a very large number of platforms (e.g. the cable-driven parallel robots of the MARIONET family, the ANG family of walking aids,r our experimental flat and the activities detection platform implemented in the day hospital Institut Claude Pompidou and EHPAD Valrose, Nice ). Among the MARIONET family we have reactivated and adapted the MARIONET-CRANE prototype for the experiment described in section 6.1.2. We have also updated our parallel 6-P ̲US prototype for the medical application mentioned in section 6.3.

REVMED: virtual reality and rehabilitation

Inria and Université Côte d'Azur have agreed to fund us for developing the platform REVMED whose purpose is to introduce end-user motion and their analysis in a virtual reality environment in order to make rehabilitation exercises more attractive and more appropriate for the rehabilitation process. The main idea is to have a modular rehabilitation station allowing to manage various exercise devices with a very low set-up time (typically 10 mn), that will be actuated in order to allow ergotherapists to favor the work of various muscles groups and the difficulty of the exercise, while monitoring the rehabilitation process with various external sensors, providing an objectification of the evaluation. Version 2 has been completed this year and we will proceed in 2020 to the first trials. These trials will consist in establishing walking patterns for non-pathological people in various conditions that will be created by a walk in a mountainous environment.