Search results for " Trajectory"
showing 10 items of 36 documents
Robust Discrete-Time Lateral Control of Racecars by Unknown Input Observers
2023
This brief addresses the robust lateral control problem for self-driving racecars. It proposes a discrete-time estimation and control solution consisting of a delayed unknown input-state observer (UIO) and a robust tracking controller. Based on a nominal vehicle model, describing its motion with respect to a generic desired trajectory and requiring no information about the surrounding environment, the observer reconstructs the total force disturbance signal, resulting from imperfect knowledge of the time-varying tire-road interface characteristics, presence of other vehicles nearby, wind gusts, and other model uncertainty. Then, the controller actively compensates the estimated force and as…
The link between vulnerability and social exclusion and criminal trajectories. An association study
2017
Este estudio tiene por objeto identificar la relación existente entre las trayectorias delictivas y los factores de vulnerabilidad y exclusión social en adolescentes en conflicto con la ley. Para ello se analizan 281 expedientes de adolescentes en conflicto con la ley de la ciudad de València y se generan 3 trayectorias delictivas: inicial, moderada y consolidada, que se asocian a indicadores de vulnerabilidad y exclusión social. Se muestran evidencias empíricas de su relación. Las trayectorias delictivas y los factores de vulnerabilidad y exclusión social se hallan plenamente conectados, entrelazados y superpuestos. La acumulación de factores de vulnerabilidad y exclusión social en adolesc…
Career intentions of Australian physical education teachers
2015
The purpose of this study was to investigate Australian physical education (PE) teachers’ career intentions and factors influencing their intentions. A sample ( N = 234) of Western Australian PE teachers responded to a questionnaire determining PE teachers’ work and the primary motivators for intention to leave the profession. Half (51.3%) of the respondents wanted a change from their current PE teacher job and 39.8% were intending to leave PE teaching. The most frequent reasons for wanting to leave PE related to: non-use of expertise, workload, school administration, and lack of opportunities for personal and professional development. Consideration should be given to mediation strategies t…
Work strain in midlife and 28-year work ability trajectories
2011
We investigated the 28-year development trajectories of work ability among initially middle-aged male and female municipal employees and the association of perceived mental and physical work strain in midlife by work ability trajectory groups.The baseline data of the Finnish longitudinal study of municipal employees (FLAME) were collected in 1981 (N=6257) with follow-ups in 1985, 1992, 1997, and 2009. Work ability was assessed in all the waves as present perceived work ability relative to lifetime best. Altogether, N=2690 had work ability data in 1981 and 2009, and at least for one wave in between these years, and were included in group-based semi-parametric mixture modeling trajectory anal…
Operation of the MAMI accelerator with a Wien filter based spin rotation system
2006
A compact spin rotation system based on a Wien filter has been installed at the Mainz microtron accelerator (MAMI). Under operation with varying spin rotation angles a significant change of focal length together with a shift of the central beam trajectory is expected. We demonstrate that these effects can be kept under control. As a consequence operation with spin rotation angles between 0° and ±90° has been achieved without compromising the beam quality and operational stability of MAMI.
Vinculación entre la vulnerabilidad y la exclusión social y las trayectorias delictivas. Un estudio de asociación
2017
RESUMEN Este estudio tiene por objeto identificar la relación existente entre las trayectorias delictivas y los factores de vulnerabilidad y exclusión social en adolescentes en conflicto con la ley. Para ello se analizan 281 expedientes de adolescentes en conflicto con la ley de la ciudad de València y se generan 3 trayectorias delictivas: inicial, moderada y consolidada, que se asocian a indicadores de vulnerabilidad y exclusión social. Se muestran evidencias empíricas de su relación. Las trayectorias delictivas y los factores de vulnerabilidad y exclusión social se hallan plenamente conectados, entrelazados y superpuestos. La acumulación de factores de vulnerabilidad y exclusión social en…
Hierarchical fuzzy/Lyapunov control for horizontal plane trajectory tracking of underactuated AUV
2010
A new hierarchical closed loop fuzzy control system for horizontal plane trajectory tracking of underactuated Autonomous Underwater Vehicles (AUV) is presented. A model for the AUV is formulated introducing a polar coordinates transformation for the velocities in the body fixed frame. It is employed to control the unactuated sway direction, the longitudinal position and the yaw by using the surge force and the yaw torque only. The highest level control is developed by employing a fuzzy inference system for obtaining the guidance control laws. The properties of the fuzzy system ensure forward surge velocity, fast convergence and Lyapunov's stability of the motion errors. A new low level kine…
A saturated strategy robustly ensures stability of the cooperative equilibrium for Prisoner's dilemma
2016
We study diffusion of cooperation in a two-population game in continuous time. At each instant, the game involves two random individuals, one from each population. The game has the structure of a Prisoner's dilemma where each player can choose either to cooperate (c) or to defect (d), and is reframed within the field of approachability in two-player repeated game with vector payoffs. We turn the game into a dynamical system, which is positive, and propose a saturated strategy that ensures local asymptotic stability of the equilibrium (c, c) for any possible choice of the payoff matrix. We show that there exists a rectangle, in the space of payoffs, which is positively invariant for the syst…
Optimal Starting Conditions for the Rendezvous Maneuver, Part 2: Mathematical Programming Approach
2008
In a companion paper (Part 1, J. Optim. Theory Appl. 137(3), [2008]), we determined the optimal starting conditions for the rendezvous maneuver using an optimal control approach. In this paper, we study the same problem with a mathematical programming approach.
Hidden Pursuits: Evaluating Gaze-selection via Pursuits when the Stimuli's Trajectory is Partially Hidden
2018
The idea behind gaze interaction using Pursuits is to leverage the human's smooth pursuit eye movements performed when following moving targets. However, humans can also anticipate where a moving target would reappear if it temporarily hides from their view. In this work, we investigate how well users can select targets using Pursuits in cases where the target's trajectory is partially invisible (HiddenPursuits): e.g., can users select a moving target that temporarily hides behind another object? Although HiddenPursuits was not studied in the context of interaction before, understanding how well users can perform HiddenPursuits presents numerous opportunities, particularly for small interfa…