56 research outputs found
Supplemental Material - Should Steering Settings be Changed by the Driver or by the Vehicle Itself?
No full textSupplemental Material for Should Steering Settings be Changed by the Driver or by the Vehicle Itself? by Timo Melman, Mark Weijerman, Joost de Winter, and David Abbink in Human Factors</p
Perversion as a social symptom: readings among Freud and Melman
No full textThis research aims to study perversion, approaching it as a social symptom. It integrates the line of research called Health, Clinic and Psychological Practices, understanding the clinic as a field of investigation through which it is possible to have access to the current social phenomena and discourse. This dissertation is composed by works with texts, in which we make explicit different forms of reading, and the texts are taken as objects of study. We carry a discussion about concepts related to the position of the author and the reader, reading, translation, interpretation and deconstruction. We work with research in psychoanalysis using a close and deconstructive reading strategy, based on the perspective that the meanings are built through the reading, in relation to, and dialoging with the text itself and with other readings. We discuss the social symptom concept, exposing how it is approached by different authors, aiming to connect it to perversion. We also register the associations made with texts by important authors in the field of psychoanalysis and in the approach of perversion. We opted to work, fundamentally, with two authors – Sigmund Freud and Charles Melman – who, coming from the psychoanalytical clinic, approach perversion in different ways. We did a deconstructive reading of the Three Essays on the Theory of Sexuality (1905) by Freud; and of the Man Without Gravity (2003), by Melman.Esta pesquisa tem como objetivo o estudo da perversão, abordando-a como sintoma social. Insere-se na linha de pesquisa intitulada Saúde, Clínica e Práticas Psicológicas, compreendendo a clínica como um campo de investigação através do qual é possível ter acesso aos fenômenos sociais e aos discursos que circulam em determinada época. Esta dissertação é composta de trabalhos com textos, sendo explicitadas as modalidades de leitura utilizadas, de modo que os textos são tomados como objeto de estudo. É realizada uma discussão acerca de questões relacionadas à posição do autor e do leitor no texto, à leitura, releitura, tradução, interpretação e desconstrução. Trabalha-se com a pesquisa em psicanálise, utilizando uma estratégia de leitura próxima e desconstrutiva, partindo da perspectiva de que os sentidos são construídos a partir da leitura, em relação e diálogo com o próprio texto e com outras leituras. Foi discutido o conceito de sintoma social, explicitando como este é abordado por autores diferentes, no intuito de fazer uma leitura acerca de como este se relaciona à perversão. Foram registradas também as associações feitas com textos de autores importantes no campo da psicanálise e na abordagem da perversão. Optou-se por trabalhar, fundamentalmente, com dois autores – Sigmund Freud e Charles Melman – que, partindo da clínica psicanalítica, abordam a perversão de formas diferentes. Foi realizada uma leitura desconstrutiva dos Três ensaios sobre a teoria da sexualidade (1905), de Freud; e de O homem sem gravidade: gozar a qualquer preço (2003), de Melman
How road narrowing impacts the trade-off between two adaptation strategies: Reducing speed and increasing neuromuscular stiffness
No full textWhen drivers encounter a road narrowing two potential adaptation strategies come into play that may increase safety margins: decreasing speed and increasing neuromuscular stiffness of the arms. These two adaption strategies have so far been studied in isolation. We expect that there is a trade-off between these two strategies, and that risk duration would impact a driver's selection of the trade-off. Specifically, we hypothesized that for a short risk duration, drivers will favour increased neuromuscular stiffness over speed reduction; and vice versa for longer risk durations. Twenty-six participants drove in a driving simulator and encountered different risk durations; realized by road narrowings (from 3.6 m to 2.2 m) of varying lengths (10 m, 100 m, 250 m, and 500 m). The neuromuscular stiffness was quantified by measuring the grip force exerted by both hands. The results show that all road narrowing conditions successfully induced driver adaptations, as a significant reduction in speed and increase in grip force was observed. However, the tested drivers did not consistently select the hypothesized different trade-offs for increasing duration of road narrowing: a low correlation was found between speed and grip force adaptations. Interestingly, individual trade-off were consistent: the within-subject variability in speed-grip force adaptations was low across the tested risk durations. Future research should further elucidate the underlying motivations for these individual adaptation strategies.Accepted Author ManuscriptHuman-Robot Interactio
The impact of steering ratio variability to road profiles on driver acceptance and driving behaviour
No full textVariable steering systems have the ability to change the ratio between the steering wheel and the front wheels while driving. These adjustable steering systems have led to an improvement in traffic and road safety and decrease in driver’s workload. A previous study concludes that driver steering behaviour is significantly dependent on vehicle speed and road curvature (number and sharpness of bends). Interestingly, variable steering ratio systems often depend on speed but not on road curvature. Variable steering ratio dependent on road curvature possibly influences driving behaviour and might be desirable for safety and driver acceptance. The goal of this research is to investigate driver acceptance and driving behaviour for two separate steering ratios (1:12 and 1:40) and two different road profiles (i.e. specific curvatures straight highway and curvy country road) at a constant speed. We hypothesize that on a curvy country road low steering ratio (1:12) leads to higher safety margins and subjective ratings, whereas on a straight highway a high steering ratio (1:40) leads to higher safety margins and subjective ratings. Therefore we conducted a within-subject driving experiment (N=24) in a fixed-based passenger vehicle simulator at constant speed. The results show that on a country road a vehicle with a low steering ratio increases time-to-line- crossing (TLC) safety margins and increases self-reported subjective ratings compared to the high steering ratio setting. Likewise, on a highway, a vehicle with a high steering ratio leads to higher safety margins and comfort rating compared to a low steering ratio. Thereby it can be concluded that steering ratio variable to the road profile improves safety and acceptance. These results provide promising evidence to make steering systems adaptable to road profile (e.g. steer-by-wire and active rear wheel steering).Mechanical Engineering | Vehicle Engineering | Human Factor
Towards Proactive Adaptive Vehicle Settings
No full textIn recent years, cars are increasingly computerized, where the handling of the vehicle can be changed to accommodate individual needs. One specific feature in current vehicles that can alter the vehicle’s dynamic behavior are driving modes: predetermined vehicle settings that drivers can select by the press of a button. Unfortunately, user studies showed that the option to switch modes is underutilized. Possible explanations include mode confusion: drivers may not know when certain vehicle settings could be used best, or they may simply forget the current mode (or forget to change mode). Besides changing driving modes when the vehicle is stationary, driving modes offer the possibility to switch while driving. In theory, this could mean that during a sportier maneuver, such as curve driving or an overtaking maneuver, the driver benefits from dynamic vehicle settings. However, in practice, it is unlikely that drivers will select their preferred vehicle setting in dynamic driving situations or for short periods. A system that automatically changes the vehicle settings for the driver could potentially solve these issues.The aim of this dissertation is to provide new quantitative and qualitative insights into the underlying principles to design a system with proactive adaptive vehicle settings: A system that automatically changes the vehicle settings to fit the individual and context-dependent needs of the driver.The first part of this thesis (Chap 2–4) investigates how people adapt to different road environments (road width and curvatures), task instructions, and car characteristics. This kind of knowledge would help to develop a system that adapts according to what the human driver would want when the location (where they drive), the target (i.e., eco vs. normal vs. sport), or the vehicle changes. The second part of the thesis (Chap 5–7) investigates how offline changes in vehicle settings (e.g., sound, powertrain settings, steering settings) affect the vehicle's dynamic behavior, driving behavior and driver experience. In this part, these questions are addressed for offline vehicle setting changes: changes that occur between driving trials and not while driving. In this way, transient effects in the data can be removed.The final part of the thesis (Chap 8–9) combines all the learned principles from the previous chapters and investigates how online changes in vehicle settings affect driving behavior and driver experience.Finally, the individual contributions of each chapter are integrated towards overarching conclusions, limitations, and future work. In short, five overarching conclusions were drawn: 1. Motivational driving models that use emotions or experiences as a construct are theoretically insightful but impractical; driving behavior could better be predicted by car state or location-specific variables. 2. A large part of the variability in driving behavior can be explained by location; location should be included in the design of an adaptive vehicle setting system. 3. The tested sport mode led to objectively more ‘sporty’ vehicle dynamics. 4. Sport mode settings are clearly perceived but do not cause speeding behavior. 5. Proactive adaptations of vehicle settings can objectively improve acceleration performance, lane-keeping, and steering performance, but are not always accepted by drivers. Human-Robot Interactio
Driver behaviour near the vehicle handling limits in vehicles with an extended linear handling region
No full textLateral acceleration is a key aspect of the vehicle response perceived by the driver. Assistance systems such as Active Rear Steering (ARS) or Torque Vectoring (TV) are developed to modify the lateral acceleration response such that the vehicle has an improved stability and an extended linear handling region. With this extended linear handling region the vehicle abruptly reaches tyre friction limitations (representing an entry into the vehicle handling limits (VHL)), this can potentially lead to dangerous situations. This thesis aims to quantify driver behaviour when being forced to drive near the VHL, in terms of how often the VHL is entered and what happens after entry. To assess this, a human factors experiment (N = 18) in a fixed base driving simulator was performed. In this experiment three different vehicle configurations were compared: (1) a conventional vehicle (Passive) (2) a vehicle with an extended linear handling region (Active) (3) a vehicle with an extended linear handling region and increased yaw response (Active Sport). In these configurations, the drivers need to drive with a fixed velocity on an oval track with Electronic Stability Control (ESC) switched off. It was expected that a conventional vehicle enters the VHL more often compared to the vehicles with an extended linear handling region. However, when entering the VHL, the vehicle with an extended linear handling region was expected to be more difficult to control due to the abrupt change in vehicle dynamics and corresponding steering feel. The results indicate that the Passive vehicle entered the VHL more frequently compared to the Active and Active Sport configurations. However, when the Active Sport configuration entered the VHL, significantly more road departures and an increased steering reversal rate compared to the Passive configuration resulted. Therefore, it can be concluded drivers enter the VHL less frequently in a vehicle with an extended linear handling region (caused by systems such as ARS or TV). However when the VHL is entered it is more difficult and dangerous for a driver to control compared to a conventional vehicle
Navigability at an unstable bifurcation: The Montaño - Murindó bifurcation of the Atrato River in Colombia
No full textThe Atrato River in Colombia should be navigable for bigger vessels when generating a corridor which should link the Atlantic Ocean with the Pacific Ocean. A likely segment of the river that forms a critical point for navigation is the point of bifurcation where the river is divided in the Montaño and Murindó branch. Both branches should be reasonably navigable, but bifurcation morphodynamics possibly render the water depth in one branch smaller than the draught of the vessel. It is noted that the Montaño branch is considered the main corridor, as this branch is shorter and generally wider. The main objective is to model and understand the morphology that evolves around the river bifurcation and discuss possible measures for creating a sustainable navigable channel. In order to create insights in these morphodynamics, a computational model has been set up. Using the software package Delft3D, a 2DH morphodynamic model of the area around the bifurcation has been made. Due to the lack of sufficient data available, a thorough morphodynamic calibration and verification is impossible. It was shown that the model predicts a development to a stable, but often highly asymmetrical discharge division. The model attains this equilibrium after 50 years of morphological modelling. This suggests the bifurcation is unstable. The evolution to an asymmetrical discharge division is mainly governed by the imposed downstream boundary water levels because a head difference over the branches determines the division of flow over the branches. The calibrated model assumes no backwater effects, which means that the shorter Montaño branch (83 km) has a larger water level gradient than the Murindó branch (91.5 km). It was shown that the unknown head difference over the branches greatly influences the global development of the branches (i.e. aggradation /degradation). Because only one bathymetrical survey was executed, erosion and sedimentation rates are unknown, which further decreases the possibility of accurately modelling the area. An important result is that when imposing the same water level gradients in both branches, the model still predicts a development to a highly asymmetrical division of flow discharge (i.e. 75% through the Montaño branch). This means that local geometrical phenomena influence the division of flow and sediments. The sharp angle of offtake of the Murindó branch results in flow separation which in turn causes a sediment trap at the entrance of this branch. As a result, the cross-section reduces significantly, which means less discharge is directed through this branch. Another phenomenon is caused by the present river bend just upstream of the point of bifurcation. This leads to a gravitational pull along the transverse slope which initially leads to an increasing bed load transport through the Murindó branch. Another local phenomenon is the Bulle effect which leads more bed load through the Murindó branch due to the river bend formed by the upstream bend and the offtaking channel. Discussing possible solutions is sometimes hypothetical as the global evolution is sensitive to the unknown downstream boundaries. The possibility of two different bend cut-offs are discussed. It was shown that the angle of offtake greatly influences the division of flow discharge and sediments. Decreasing the offtake-angle of the Murindó branch from 90° to 30° means the Murindó branch gets dominant (60% flow discharge through this branch instead of 20%). As the internal connection between the branches can result in significant backwater effects, it can be a simple solution to cut off this connection. In conclusion, the present available data prove to be insufficient. Measuring stage and discharges in both branches, river bed profiles and sediment characteristics can indicate which branch will be dominant and enable future decision making.River EngineeringHydraulic EngineeringCivil Engineering and Geoscience
Does haptic steering guidance instigate speeding?: A driving simulator study into causes and remedies
No full textAn important issue in road traffic safety is that drivers show adverse behavioral adaptation (BA) to driver assistance systems. Haptic steering guidance is an upcoming assistance system which facilitates lane-keeping performance while keeping drivers in the loop, and which may be particularly prone to BA. Thus far, most experiments on haptic steering guidance have measured driver performance while the vehicle speed was kept constant, and so the degree of BA could not be established. The aim of the present driving simulator study was to examine whether haptic steering guidance causes BA in the form of speeding, and to evaluate two types of haptic steering guidance designed not to suffer from BA. Twenty-four participants drove a 1.8 m wide car for 13.9 km on a curved road, with cones demarcating a single 2.2 m narrow lane. Participants completed four conditions in a counterbalanced design: no guidance (Manual), continuous haptic guidance (Cont), continuous guidance that linearly reduced feedback gains from full guidance at 125 km/h towards manual control at 130 km/h and above (ContRF), and haptic guidance provided only when the predicted lateral position was outside a bandwidth (Band). Participants were familiarized with each condition prior to the experimental runs and were instructed to drive as they normally would do while minimizing the number of cone hits. Compared to Manual, the Cont condition yielded a significantly higher driving speed (on average by 7 km/h), whereas ContRF and Band did not. All three guidance conditions yielded better lane-keeping performance than Manual, whereas Cont and ContRF yielded lower self-reported workload than Manual. In conclusion, continuous steering guidance entices drivers to increase their speed, thereby diminishing its potential safety benefits. It is possible to prevent BA while retaining safety benefits by making a design adjustment either in lateral (Band) or in longitudinal (ContRF) direction.Mechanical, Maritime and Materials EngineeringBioMechanical Desig
Optimizing the observation schedule of the JANUS instrument to improve the Jovian system ephemerides
No full textThe Jupiter Icy moons Explorer (JUICE) will generate ephemerides of the Galilean moons to assess their ability to sustain live. However, determining the ephemerides only using radiometric tracking (acquired using PRIDE and 3GM) results in an unstable solution which is related to the absence of flybys of especially Io, such that its dynamics can only be estimated indirectly (through the Laplace resonance). This problem is partially mitigated in this thesis by optimizing the observation schedule for optical astrometry of Io (provided by JANUS) using the NSGA-II algorithm. The optimal epochs for space-based astrometry are found to be preferentially distributed around the closest approaches of JUICE with respect to Io. During these events, the observations show a high sensitivity with respect to the dynamics of Io and have a low positional uncertainty. Using the optimized astrometry, both the condition number and formal errors can be substantially reduced.Aerospace Engineerin
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