Ensamblaje e implementación de arquitectura cuadrúpeda modular

This paper describes the assembling process of a quadrupedal architecture using the modular robotic system Mecabot. Several possible topologies are addressed to finally opt for a design that allows the use of an active column. Based on this, the mathematical model of the control is proposed to perform the movements of displacement, open turn and rotation. The locomotion profiles for these first two movement modalities are bio-inspired. For the rotation modality, a characteristic quadrupedal robot transition is used to allow the correct rotation execution without using a great number of degrees of freedom. The robot is tested on structured and unstructured terrains by measuring its speed in function of the movement frequency variation. For the open turn modality, the described circumference radius is measured in function of the offset variation. With the tests, the second Mecabot configuration with legs is finally obtained complementing the research work carried out for apodal configurations (snake, wheel caterpillar) and hexapod.En este documento se describe el proceso de ensamblaje de una arquitectura cuadrúpeda utilizando el sistema robótico modular Mecabot. Varias posibles topologías son abordadas para finalmente optar por un diseño que permita emplear una columna activa. En base a ello es planteado el modelo matemático del control para realizar los movimientos de desplazamiento, giro abierto y giro cerrado. Los perfiles de locomoción que debe ejecutar el robot para estas dos primeras modalidades de movimiento son bioinspirados. Para la modalidad de giro cerrado se emplea una transición característica de los robots cuadrúpedos con el fin de poder seguir ejecutando correctamente la rotación sin necesidad de emplear un número mayor de grados de libertad. El robot es probado en terrenos estructurados y no estructurados midiendo su velocidad en función de la variación de la frecuencia de movimiento, para la modalidad de giro abierto se mide el radio de la circunferencia descrito en función de la variación del offset. Con las pruebas realizadas finalmente se obtiene la segunda configuración con patas implementada en el Mecabot, complementando así los trabajos de investigación previamente realizados para la configuración hexápoda y configuraciones ápodas (serpiente, oruga rueda)

Autonomous Task-Based Evolutionary Design of Modular Robots

In an attempt to solve the problem of finding a set of multiple unique modular robotic designs that can be constructed using a given repertoire of modules to perform a specific task, a novel synthesis framework is introduced based on design optimization concepts and evolutionary algorithms to search for the optimal design. Designing modular robotic systems faces two main challenges: the lack of basic rules of thumb and design bias introduced by human designers. The space of possible designs cannot be easily grasped by human designers especially for new tasks or tasks that are not fully understood by designers. Therefore, evolutionary computation is employed to design modular robots autonomously. Evolutionary algorithms can efficiently handle problems with discrete search spaces and solutions of variable sizes as these algorithms offer feasible robustness to local minima in the search space; and they can be parallelized easily to reducing system runtime. Moreover, they do not have to make assumptions about the solution form. This dissertation proposes a novel autonomous system for task-based modular robotic design based on evolutionary algorithms to search for the optimal design. The introduced system offers a flexible synthesis algorithm that can accommodate to different task-based design needs and can be applied to different modular shapes to produce homogenous modular robots. The proposed system uses a new representation for modular robotic assembly configuration based on graph theory and Assembly Incidence Matrix (AIM), in order to enable efficient and extendible task-based design of modular robots that can take input modules of different geometries and Degrees Of Freedom (DOFs). Robotic simulation is a powerful tool for saving time and money when designing robots as it provides an accurate method of assessing robotic adequacy to accomplish a specific task. Furthermore, it is difficult to predict robotic performance without simulation. Thus, simulation is used in this research to evaluate the robotic designs by measuring the fitness of the evolved robots, while incorporating the environmental features and robotic hardware constraints. Results are illustrated for a number of benchmark problems. The results presented a significant advance in robotic design automation state of the art

Interlocking structure design and assembly

Many objects in our life are not manufactured as whole rigid pieces. Instead, smaller components are made to be later assembled into larger structures. Chairs are assembled from wooden pieces, cabins are made of logs, and buildings are constructed from bricks. These components are commonly designed by many iterations of human thinking. In this report, we will look at a few problems related to interlocking components design and assembly. Given an atomic object, how can we design a package that holds the object firmly without a gap in-between? How many pieces should the package be partitioned into? How can we assemble/extract each piece? We will attack this problem by first looking at the lower bound on the number of pieces, then at the upper bound. Afterwards, we will propose a practical algorithm for designing these packages. We also explore a special kind of interlocking structure which has only one or a small number of movable pieces. For example, a burr puzzle. We will design a few blocks with joints whose combination can be assembled into almost any voxelized 3D model. Our blocks require very simple motions to be assembled, enabling robotic assembly. As proof of concept, we also develop a robot system to assemble the blocks. In some extreme conditions where construction components are small, controlling each component individually is impossible. We will discuss an option using global controls. These global controls can be from gravity or magnetic fields. We show that in some special cases where the small units form a rectangular matrix, rearrangement can be done in a small space following a technique similar to bubble sort algorithm