26,889 research outputs found
MIMO PID Controller Tuning Method for Quadrotor Based on LQR/LQG Theory
In this work, a new pre-tuning multivariable PID (Proportional Integral Derivative)
controllers method for quadrotors is put forward. A procedure based on LQR/LQG (Linear Quadratic
Regulator/Gaussian) theory is proposed for attitude and altitude control, which suposes a considerable
simplification of the design problem due to only one pretuning parameter being used. With the aim to
analyze the performance and robustness of the proposed method, a non-linear mathematical model of
the DJI-F450 quadrotor is employed, where rotors dynamics, together with sensors drift/bias properties
and noise characteristics of low-cost commercial sensors typically used in this type of applications are
considered. In order to estimate the state vector and compensate bias/drift effects in the measures,
a combination of filtering and data fusion algorithms (Kalman filter and Madgwick algorithm for attitude
estimation) are proposed and implemented. Performance and robustness analysis of the control system
is carried out by employing numerical simulations, which take into account the presence of uncertainty
in the plant model and external disturbances. The obtained results show the proposed controller design
method for multivariable PID controller is robust with respect to: (a) parametric uncertainty in the plant
model, (b) disturbances acting at the plant input, (c) sensors measurement and estimation errors
El filósofo de la esperanza
Hay motivos y razones para la esperanza, pero sobre todo hay posibilidad de encontrar fundamentos para esta esperanza. La reedición de la obra insigne de enrst bloch por la editorial taurus1 nos permite la posibilidad de recuperar una mirada abierta por eThere are motives and reasons for a new hope, but most of all there is a possibility to find fundamentals for this hope. The reedition of bloch's distinguished work by taurus2 publishing house give us the opportunity to recover a wide glance by ernst blo
Optical sensor to measure the projectile velocity
Displays & Photonics Applications Group (GDAF), belonging to Electronics Technology Department of University Carlos III of Madrid (Spain), has designed and implemented a simple, cost-effective, and robust optoelectronic system to measure online the average velocity of a projectile. This system is able to measure velocities ranged between 100m/s and 1200m/s). Potential applications are focused on experimental impact tests on aircraft and spacecraft structures. We are seeking potential collaborations with international/national research centres and enterprises to extent the range of potential applications
Cryomorphological topographies in the study of ice caves
Producción CientÃficaThe current interest in ice caves requires that their varied manifestations be known as accurately as possible in view of their responses to a global change and also to their great potential as paleoenvironmental witnesses. This phenomenon has been known about for a long time but is still scarcely studied from the point of view of its cryological values and the evolution and distribution of many of their morphologies. For this, the development of cryomorphological topographies from traditional techniques to geodetic surveys with different tools, including terrestrial laser scanning, is one of the most current ways to characterize and quantify this type of cryospheric phenomena. It represents a new kind of periglacial cartography whose use is feasible in spite of the difficulties these environments present.Ministerio de EconomÃa, Industria y Competitividad (project CGL2015-68144-R
Intervenir en el mundo de los átomos: Feynman y los fulerenos
Hace medio siglo el fÃsico Richard Feynman, ganador del Premio Nóbel, fue invitado a pronunciar un discurso en una institución tecnológica de California. Lo que manifestó en aquella intervención influirÃa para siempre en las generaciones futuras interesadas por la exploración del enorme potencial de un universo a escala atómica. Una derivada de aquel momento y punto de desarrollo es el descubrimiento de los fulerenos (también conocidos como "bucicyballs"), que ha abierto un nuevo campo para la quÃmica del carbono, y que han beneficiado a diversos campos cientÃficos, entre ellos la Biomedicina, como se pone de manifiesto en el presente artÃcul
Todo vale para construir un sermón : microtextos en la predicación castellana medieval
El sermón en sÃ, dada su naturaleza oral, es un texto breve. Una de sus peculiaridades en la época medieval, y aun después, radica en\ud
su dependencia, a la hora de construirse, de una multiplicidad de fuentes\ud
que son, a su vez y en su mayorÃa, microtextos (auctoritates, exempla,\ud
similitudines, proverbios, etc.), de carácter más o menos autónomo,\ud
cuyos rasgos definidores, trayectoria y fuentes nos resultan cada vez más\ud
conocidos. En los casos de mayor vinculación, el sermón medieval se\ud
limita a adaptar mÃnimamente esas piezas breves, reorientándolas hacia sus\ud
intereses pastorales.The sermon as such, given its oral nature, is a brief text. One of its pecularities in medieval times, and afterwards, is due to its dependence --at the time it is composed-- from various sources which are, at the same time and in the mayority of the cases, microtexts that have a character more\ud
or less autonomous, and whose defined traits, trajectory and sources are for\ud
us more recognizable every day. Incases of greater vinculation, the medieval\ud
sermon merely adapts minimally cited microtexts, which were utilized due to\ud
its clerical intentions
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