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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Usability of Various Input Devices on a Steering Task

Fund, Ian 01 May 2015 (has links)
In this study we examined the differences of performance of various input devices on a steering task. Two paths were created, one easy and one hard, with the harder path having more turning points to navigate with one of three different input devices: mouse and keyboard, Xbox 360 controller, and a joystick. Participants were also exposed to low or high stress conditions. High stress was caused by playing loud short bursts of music over headphones worn by participants during testing. Results indicated the mouse and keyboard performed better in all cases. There was no significant difference between the Xbox controller and joystick. No differences were found in the low and high stress conditions. Differences in sex were found, even when controlling for video game experience. These findings indicate that the mouse and keyboard is the best device to use on a steering task.
42

Steering drift and wheel movement during braking: static and dynamic measurements

Klaps, J., Day, Andrew J. January 2005 (has links)
Yes / This paper reports on an experimental investigation into braking-related steering drift in motor vehicles, and follows on from a previous paper by the authors in which it was concluded that braking can cause changes in wheel alignment that in turn affect the toe-steer characteristics of each wheel and therefore the straight-line stability of the vehicle during braking. Changes in suspension geometry during braking, their magnitude and the relationships between the braking forces and the suspension geometry and compliance are further investigated in an experimental study of wheel movement arising from compliance in the front suspension and the steering system of a passenger car during braking. Using a kinematic and compliance (K&C) test rig, movement of the front wheels and the suspension subframe, together with corresponding changes in suspension and steering geometry under simulated braking conditions, have been measured and compared with dynamic measurements of the centre points of the front wheels. The results have enabled the causes and effects of steering drift during braking to be better understood in the design of front suspension systems for vehicle stability during braking.
43

Steering drift and wheel movement during braking: parameter sensitivity studies

Klaps, J., Day, Andrew J. January 2003 (has links)
Yes / In spite of the many signi cant improvements in car chassis design over the past two decades, steering drift during braking where the driver must apply a corrective steering torque in order to maintain course can still be experienced under certain conditions while driving. In the past, such drift, or `pull¿, would have been attributed to side-to-side braking torque variation [1], but modern automotive friction brakes and friction materials are now able to provide braking torque with such high levels of consistency that side-to-side braking torque variation is no longer regarded as a cause of steering drift during braking. Consequently, other in uences must be considered. This paper is the rst of two papers to report on an experimental investigation into braking-related steering drift in motor vehicles. Parameters that might in uence steering drift during braking include suspension compliance and steering o set, and these have been investigated to establish the sensitivity of steering drift to such parameters. The results indicate how wheel movement arising from compliance in the front suspension and steering system of a passenger car during braking can be responsible for steering drift during braking. Braking causes changes in wheel alignment which in turn a ect the toe steer characteristics of each wheel and therefore the straight-line stability during braking. It is concluded that a robust design of suspension is possible in which side-to-side variation in toe steer is not a ected by changes in suspension geometry during braking, and that the magnitude of these changes and the relationships between the braking forces and the suspension geometry and compliance require further investigation, which will be presented in the second paper of the two.
44

Tools and techniques for locating and steering parallel simulations through bifurcation points

Bennett, Daniel M. 29 November 2010 (has links)
No description available.
45

Design of controlled RF switch for beam steering antenna array

Abusitta, M.M., Zhou, Dawei, Abd-Alhameed, Raed, Excell, Peter S. January 2008 (has links)
Yes / A printed dipole antenna integrated with a duplex RF switch used for mobile base station antenna beam steering is presented. A coplanar waveguide to coplanar strip transition was adopted to feed the printed dipole. A novel RF switch circuit, used to control the RF signal fed to the dipole antenna and placed directly before the dipole, was proposed. Simulated and measured data for the CWP-to-CPS balun as well as the measured performance of the RF switch are shown. It has demonstrated the switch capability to control the beam in the design of beam steering antenna array for mobile base station applications.
46

Semantic Interaction for Visual Analytics: Inferring Analytical Reasoning for Model Steering

Endert, Alex 18 July 2012 (has links)
User interaction in visual analytic systems is critical to enabling visual data exploration. Through interacting with visualizations, users engage in sensemaking, a process of developing and understanding relationships within datasets through foraging and synthesis. For example, two-dimensional layouts of high-dimensional data can be generated by dimension reduction models, and provide users with an overview of the relationships between information. However, exploring such spatializations can require expertise with the internal mechanisms and parameters of these models. The core contribution of this work is semantic interaction, capable of steering such models without requiring expertise in dimension reduction models, but instead leveraging the domain expertise of the user. Semantic interaction infers the analytical reasoning of the user with model updates, steering the dimension reduction model for visual data exploration. As such, it is an approach to user interaction that leverages interactions designed for synthesis, and couples them with the underlying mathematical model to provide computational support for foraging. As a result, semantic interaction performs incremental model learning to enable synergy between the user's insights and the mathematical model. The contributions of this work are organized by providing a description of the principles of semantic interaction, providing design guidelines through the development of a visual analytic prototype, ForceSPIRE, and the evaluation of the impact of semantic interaction on the analytic process. The positive results of semantic interaction open a fundamentally new design space for designing user interactions in visual analytic systems. This research was funded in part by the National Science Foundation, CCF-0937071 and CCF-0937133, the Institute for Critical Technology and Applied Science at Virginia Tech, and the National Geospatial-Intelligence Agency contract #HMI1582-05-1-2001. / Ph. D.
47

Performance of an electro-hydraulic active steering system

Fischer, Eric, Sitte, André, Weber, Jürgen, Bergmann, Erhard, de la Motte, Markus 27 April 2016 (has links) (PDF)
Hydrostatic steering systems are used in construction and agricultural machines alike. Because of their high power density, hydraulic drives are qualified for the use in vehicles with high steering loads. Conventional hydrostatic steering systems are limited in terms of steering comfort and driver assistance. For realisation of appropriate steering functions, electro-hydraulic solutions are necessary. This paper provides an overview on existing implementations and introduces a novel steering system. The presented active steering system with independent meter-in and meter-out valves fills the gap between existing active steering systems and steer-by-wire solutions. An appropriate control and safety concept provides advanced steering functions for on-road usage without the fully redundant structure of steer-by-wire systems.
48

Active control of narrow tilting vehicle dynamics

Robertson, James January 2014 (has links)
Narrow tilting vehicles offer an opportunity to tackle both traffic congestion and carbon emissions having a small footprint, low weight and small frontal area. Their narrow width requires that they tilt into corners in order to maintain stability; this may be achieved by means of an automated tilt control system. A three-wheeled tilting vehicle prototype, known as the Compact Low Emission Vehicle for uRban transport (CLEVER), was constructed at the University of Bath in 2006. The vehicle was equipped with a direct tilt control system in which a pair of hydraulic actuators applied a moment between the cabin and a non-tilting base. This tilt control system provided satisfactory steady state performance but limited transient stability. High tilt rate demands associated with rapid steering inputs would lead to large tilting moments being applied to the non-tilting rear engine module; this, combined with the engine module’s own propensity to roll out of the bend, could cause the inside wheel to lift and the vehicle to capsize. This thesis details the implementation of a Steering Direct Tilt Control (SDTC) system, whereby the front wheel steer angle is used to generate some of the tilting moment, on the prototype CLEVER Vehicle. Simulation and experimental results are presented which show a 40% reduction in load transfer across the rear axle during a transient ramp steer manoeuvre. The influence of the SDTC system, and associated steer angle alteration, on the vehicle trajectory is considered. A human driver is found to be capable of adapting their steer inputs such that they can follow their chosen path. Finally, a feed-forward control strategy is shown to reduce the load transfer across the rear axle by an additional 30% in transient situations, but only if the steer input signal is sufficiently free of noise.
49

Konstrukční návrh měřicího volantu / Design of a measuring steering wheel

Papp, Tomáš January 2015 (has links)
This diploma thesis describes construction design of a measuring steering wheel. This mechanism replaces the original steering wheel in the tested vehicle. Connection is made via steering shaft through an adapter. Measured parameters are steering torque and angular position of steering while driving. Measurements obtained during test-ride show some of the dynamic aspects of the tested vehicle.
50

Performance of an electro-hydraulic active steering system

Fischer, Eric, Sitte, André, Weber, Jürgen, Bergmann, Erhard, de la Motte, Markus January 2016 (has links)
Hydrostatic steering systems are used in construction and agricultural machines alike. Because of their high power density, hydraulic drives are qualified for the use in vehicles with high steering loads. Conventional hydrostatic steering systems are limited in terms of steering comfort and driver assistance. For realisation of appropriate steering functions, electro-hydraulic solutions are necessary. This paper provides an overview on existing implementations and introduces a novel steering system. The presented active steering system with independent meter-in and meter-out valves fills the gap between existing active steering systems and steer-by-wire solutions. An appropriate control and safety concept provides advanced steering functions for on-road usage without the fully redundant structure of steer-by-wire systems.

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