27 research outputs found
Robot competitions trick students into learning
It has been shown in the past that robots help to bring theoretical concepts into practice, while at the same time increasing the motivation of the students. Despite these benefits, robots are hardly ever integrated in education programs and at the same time students feel that they have the competences nor the infrastructure to build a robot on their own. Therefore the workgroup electronics (WELEK) of Ghent University gives students the opportunity to build a robot by organizing workshops and competitions. Up until now, four competitions were organized in which over 200 students voluntarily participated. This paper describes our approach in the hope that it will inspire other educators to do the same thing. We also measured the effectiveness of our competitions by sending each of the participants a questionnaire. The results confirm that students acquire relevant technical competences by building a robot, learn to work as a team and are challenged to use their creativity
Oncilla robot: a versatile open-source quadruped research robot with compliant pantograph legs
We present Oncilla robot, a novel mobile, quadruped legged locomotion
machine. This large-cat sized, 5.1 robot is one of a kind of a recent,
bioinspired legged robot class designed with the capability of model-free
locomotion control. Animal legged locomotion in rough terrain is clearly shaped
by sensor feedback systems. Results with Oncilla robot show that agile and
versatile locomotion is possible without sensory signals to some extend, and
tracking becomes robust when feedback control is added (Ajaoolleian 2015). By
incorporating mechanical and control blueprints inspired from animals, and by
observing the resulting robot locomotion characteristics, we aim to understand
the contribution of individual components. Legged robots have a wide mechanical
and control design parameter space, and a unique potential as research tools to
investigate principles of biomechanics and legged locomotion control. But the
hardware and controller design can be a steep initial hurdle for academic
research. To facilitate the easy start and development of legged robots,
Oncilla-robot's blueprints are available through open-source. [...
Testing the Wyart-Cates model for non-Brownian shear thickening using bidisperse suspensions
There is a growing consensus that shear thickening of concentrated
dispersions is driven by the formation of stress-induced frictional contacts.
The Wyart-Cates (WC) model of this phenomenon, in which the microphysics of the
contacts enters solely via the fraction of contacts that are frictional,
can successfully fit flow curves for suspensions of weakly polydisperse
spheres. However, its validity for "real-life", polydisperse suspensions has
yet to be seriously tested. By performing systematic simulations on bidisperse
mixtures of spheres, we show that the WC model applies only in the monodisperse
limit and fails when substantial bidispersity is introduced. We trace the
failure of the model to its inability to distinguish large-large, large-small
and small-small frictional contacts. By fitting our data using a polydisperse
analogue of that depends separately on the fraction of each of these
contact types, we show that the WC picture of shear thickening is incomplete.
Systematic experiments on model shear-thickening suspensions corroborate our
findings, but highlight important challenges in rigorously testing the WC model
with real systems. Our results prompt new questions about the microphysics of
thickening for both monodisperse and polydisperse systems.Comment: 9 pages, 8 figures, ancillary informatio