International election monitoring has been touted as a regional norm in the Western hemisphere, but recent reforms in Venezuela and Nicaragua substituted a diminished international role of electoral accompaniment. This article traces the initial acceptance and later limitation of international election monitoring in those countries to explore whether the change constitutes norm localization or norm defection. It concludes that the norm is not as well institutionalized in the hemisphere as conventionally thought, and that models need to assess together national and international monitoring capacities.La observación electoral internacional se ha considerado una norma regional en el hemisferio occidental, pero las recientes reformas en Venezuela y Nicaragua la han cambiado a un reducido papel internacional de acompañamiento electoral. El presente artículo estudia la aceptación inicial y posterior limitación de la observación electoral internacional en estos países, para analizar si el cambio constituye una localización o un abandono de la norma. Concluye que la norma no está tan bien institucionalizada en el hemisferio como convencionalmente se cree y que es necesario que los modelos evalúen conjuntamente las capacidades de observación nacionales e internacionales
There are several ubiquitous kinematic structures that are used in industrial robots, with the most prominent being a six-axis angular structure. However, researchers are experimenting with task-based mechanism synthesis that could provide higher efficiency with custom optimized manipulators. Many studies have focused on finding the most efficient optimization algorithm for task-based robot manipulators. These manipulators, however, are usually optimized from simple modular joints and links, without exploring more elaborate modules. Here, we show that link modules defined by small numbers of parameters have better performance than more complicated ones. We compare four different manipulator link types, namely basic predefined links with fixed dimensions, straight links that can be optimized for different lengths, rounded links, and links with a curvature defined by a Hermite spline. Manipulators are then built from these modules using a genetic algorithm and are optimized for three different tasks. The results demonstrate that manipulators built from simple links not only converge faster, which is expected given the fewer optimized parameters, but also converge on lower cost values.
Design methods have been improving with an increasing level of algorithmic support for some time. The most recent advances include generative design and various optimization methods. However, the automated design tools are often focused on a single stage of the design process, for example, kinematics design, mechanical topology, or drive selection. In this paper, we show the whole design process of a robotic manipulator in an automated workflow. The method consisted of two main parts: a genetic optimization of the kinematic structure and an iterative automated CAD design. The method was then applied to a case study in which a manipulator with five degrees of freedom for a handling task was designed.
Robots that have been optimized in simulation often underperform in the real world in comparison to their simulated counterparts. This difference in performance is often called a reality-gap. In this paper, we use two methods, genetic algorithm and topology optimization, to optimize a quadruped robot. We look at the original and optimized robots’ performance in simulation and reality and compare the results. Both methods show improvement in the robot’s efficiency, however the topology optimization behaves in a more predictable manner and shows similar results in simulation and in real laboratory testing. Modifying robot morphology with a genetic algorithm, although less predictable, has a potential for more improvement in efficiency.