Francisco González

Learn More
—A new topologically correct hybrid transformer model is developed for low and midfrequency transient simulations. Power transformers have a conceptually simple design, but behaviors can be very complex. The selection of the most suitable representation for a given behavior depends on the type of transformer to be simulated, the frequency range, and other(More)
In this work, a multibody dynamics model of a wheeled mobile robot is developed to characterize the terrain reaction forces in terms of the physical and control parameters of the system. A common strategy for simulating the motion of mobile robots on soft soil is to compute the soil reaction forces using terramechanics models and to solve a forward dynamics(More)
Despite the importance given to the computational efficiency of multibody system (MBS) simulation tools, there is a lack of standard benchmarks to measure the performance of these kinds of numerical simulations. This works proposes a collaborative benchmarking framework to measure and compare the performance of different MBS simulation methods. The(More)
The paper documents a new transformer model in ATPDraw called XFMR. This model handles 3-phase transformers with two or three windings. Autotransformers and all Wye and Delta couplings are supported. The model includes an inverse inductance matrix for the leakage description, optional frequency dependent winding resistance, capacitive coupling, and a(More)
This article presents an architecture to manage a multime-dia over IP delivery service. It considers user's expectations as the main metric that defines the quality of the service thus assuring an efficient resource and effort investment by network operators. The proposed architecture integrates into a single platform both required elements as well as(More)
The Galileo In-Orbit Validation Element (GIOVE) is an experiment led by the European Space Agency (ESA) aimed at supporting the on-going implementation of Galileo, the European global navigation satellite system (GNSS). Among the objectives of the GIOVE Mission are the validation and characterization of the on-board clock technologies. The current baseline(More)
Mobility analysis is of great importance in the area of planetary exploration with wheeled robots (rovers). Environmental uncertainties and the autonomous nature of operations require an adequate knowledge of system behaviour in complex motion scenarios. The wheel-soil interaction poses a main challenge in such analyses. Rovers have to negotiate(More)
The endemic flora of the Canary Islands is remarkable but highly vulnerable to environmental changes. Several factors, such as fire, could be threatening. The purpose of this study was to analyze various treatments in endemic threatened species which could have been growing in the understory of the Canary pine forest. We attempted to improve germination(More)