Singularity Analysis of PAMINSA Manipulators

International audiencePAMINSA (PArallel Manipulator of the I.N.S.A.) is a new family of parallel manipulators from four to six degrees of freedom (DOF), which have been developed at the I.N.S.A. in Rennes. The particularity of these manipulators is the decoupling of displacements in the horizontal plane from its translation along the vertical axis. Such a decoupling improves some mechanical properties of the manipulator making it more efficient. In this paper a singularity analysis of PAMINSA with four, five and six degrees of freedom is presented. The nature of each kind of singularity is discussed

Improvement of Functional Performance of Spatial Parallel Manipulators Using Mechanisms of Variable Structure

International audienceA procedure for the increase of singularity-free zones in the workspace of spatial parallel manipulators is presented in this paper. The procedure is based on the control of the pressure angles in the joints of the manipulator. The zones, which cannot be reached by the manipulator, are detected. For increase of the reachable workspace of the manipulator the legs of variable structure are proposed. The design of the optimal structure of the spatial parallel manipulator 3-RPS is illustrated by a numerical simulation

Formación emprendedora de la facultad de Ingeniería Química (FIQ) 2015-2018

In this article we present the experience of Entrepreneurial Training of the Facultyof Chemical Engineering (FIQ) 2015-2018 is presented, which had as purpose to develop skills, talents and entrepreneurial attitudes in the students, faculty and administrative staff of the faculty to contribute to its growth personal and professional. The process began in September 2015 and since then three generations have been trained, with a total of 152 participants, of which: 12 teachers, 6 administrative employees, 124 students from first to fifth year of the Chemical Engineering career and graduates of the FIQ, as well as 10 students participating in other UNI careers, stories such as industrial, mechanical, agricultural, civil and architectural engineering. Taking place in March 2018, the first Graduation of Entrepreneurs in which 32 certificates of approval of the Entrepreneurial Training course and Design of Business Plans were delivered, with the presentation of 11 completed business plans.En este artículo se presenta la experiencia de Formación Emprendedora de la Facultad de Ingeniería Química (FIQ) 2015-2018, que tuvo como propósito desarrollar habilidades, talentos y actitudes emprendedoras en los estudiantes, personal docente y administrativo de la facultad para contribuir a su crecimiento personal y profesional. El proceso inició en septiembre del año 2015 y desde entonces se han formado tres generaciones, capacitando a un total de 152 participantes de los cuales: 12 han sido docentes, 6 participantes del personal administrativo, 124 estudiantes de primer a quinto año de la carrera de ingeniería química y egresados de la FIQ, así como 10 estudiantes que pertenecen a otras carreras de UNI, tales como, ingeniería Industrial, mecánica, agrícola, civil y arquitectura. Realizándose en marzo de 2018, la primer Graduación de Emprendedores en la cual se entregaron 32 diplomas de aprobación del curso Formación Emprendedora y Diseño de Planes de Negocios, con la presentación de 11 planes de negocios concluidos

UNA APLICACIÓN DE TEORÍA DE TORNILLOS PARA LA IDENTIFICACIÓN DE SINGULARIDADES EN UN NOVEDOSO ROBOT PARALELO RECONFIGURABLE

This paper reports the application of the screw theory as a tool for the determination of the singular configurations of a reconfigurable parallel robot composed of two parallel sub-manipulators. The Jacobian matrices of the robot, key elements for the identification of singularities, are easily determined when the input-output equation of velocity of the robot is obtained by the application of some screw theory basic operations. Through this application, the inverse, direct and combined singularities are clearly identified, and their graphical representations can be obtained almost intuitively.Este trabajo reporta la aplicación de teoría de tornillos como una herramienta para la determinación de las configuraciones singulares de un robot paralelo reconfigurable conformado por dos sub-manipuladores paralelos. Las matrices Jacobiana del robot, piezas fundamentales para la identificación de las singularidades, se determinan fácilmente cuando la ecuación de entrada y salida de velocidad del robot es obtenida a través de la aplicación de algunas operaciones básicas de teoría de tornillos. Mediante esta aplicación, las singularidades directas, inversas y combinadas son claramente identificadas, y su representación gráfica puede ser obtenida casi intuitivamente

UNA APLICACIÓN DE TEORÍA DE TORNILLOS PARA LA IDENTIFICACIÓN DE SINGULARIDADES EN UN NOVEDOSO ROBOT PARALELO RECONFIGURABLE

This paper reports the application of the screw theory as a tool for the determination of the singular configurations of a reconfigurable parallel robot composed of two parallel sub-manipulators. The Jacobian matrices of the robot, key elements for the identification of singularities, are easily determined when the input-output equation of velocity of the robot is obtained by the application of some screw theory basic operations. Through this application, the inverse, direct and combined singularities are clearly identified, and their graphical representations can be obtained almost intuitively.Este trabajo reporta la aplicación de teoría de tornillos como una herramienta para la determinación de las configuraciones singulares de un robot paralelo reconfigurable conformado por dos sub-manipuladores paralelos. Las matrices Jacobiana del robot, piezas fundamentales para la identificación de las singularidades, se determinan fácilmente cuando la ecuación de entrada y salida de velocidad del robot es obtenida a través de la aplicación de algunas operaciones básicas de teoría de tornillos. Mediante esta aplicación, las singularidades directas, inversas y combinadas son claramente identificadas, y su representación gráfica puede ser obtenida casi intuitivamente

Increase of Singularity-Free Zones in the Workspace of Parallel Manipulators Using Mechanisms of Variable Structure

International audienceThis paper is focused on the study of singularity of planar parallel manipulators taking into account the force transmission, i.e. study of singularity of planar manipulator by introducing the force transmission factor. Thus the singularity zones in the workspace of the manipulator are defined not only by kinematic criterions from the theoretical perfect model of the manipulator but also by the quality of force transmission. For this purpose, the pressure angle is used as an indicator of force transmission. The optimal control of the pressure angle for a given trajectory of the manipulator is realized by means of legs with variable structure. The suggested procedure to determination of the optimal structure of the planar parallel manipulator 3-RPR is illustrated by two numerical simulations

Kinematic analysis and dimensional optimization of a 2R2T parallel manipulator

International audienceThe need of a device providing two translational (2T) and two rotational (2R) movements led us to the design a 3UPS-1RPU parallel manipulator. The manipulator consisted on a mobile platform connected to a base through four legs. That is, the manipulator layout has one central leg and three external legs at the same radial distance. By studying different locations of the legs anchoring point, we improved the first layout design, yet not the optimal one. On this basis, this paper focus on the optimal dimensional design of the manipulator. To this end, we put forward the kinematics equations of the manipulator in accordance to the anchoring points coordinates. Through a numerical approach, the equations enable to find the manipulator workspace. Also, we find a global manipulability index using a local dexterity measure. The latter index serves as optimal function. The optimization process considers joint constraints. Thus, we built a nonlinear optimization problem solved through sequential quadratic programming algorithms. We start by optimizing only a small set of parameters rather than the entire set, which gives us insights on the initial guess to optimize using the entire set. The optimal design layout varies from the original layout. Findings suggest that a task-oriented reconfiguration strategy can improve manipulator performance

Real Coded Mixed Integer Genetic Algorithm for Geometry Optimization of Flight Simulator Mechanism Based on Rotary Stewart Platform

Featured Application Low-cost flight simulators with electric rotary actuators and optimized geometry for flight simulation. Designing the motion platform for the flight simulator is closely coupled with the particular aircraft's flight envelope. While in training, the pilot on the motion platform has to experience the same feeling as in the aircraft. That means that flight simulators need to simulate all flight cases and forces acting upon the pilot during flight. Among many existing mechanisms, parallel mechanisms based on the Stewart platform are suitable because they have six degrees of freedom. In this paper, a real coded mixed integer genetic algorithm (RCMIGA) is applied for geometry optimization of the Stewart platform with rotary actuators (6-RUS) to design a mechanism with appropriate physical limitations of workspace and motion performances. The chosen algorithm proved that it can find the best global solution with all imposed constraints. At the same time, the obtained geometry can be manufactured because integer solutions can be mapped to available discrete values. Geometry is defined with a minimum number of parameters that fully define the mechanism with all constraints. These geometric parameters are then optimized to obtain custom-tailored geometry for aircraft flight simulation