Flight-path vector symbology in tunnel-in-the-sky displays

Aerospace Engineerin

Haptic feedback; making safety boundaries tangible

Aerospace Engineerin

Cybernetics of Tunnel-in-the-Sky Displays

Consensus is growing that the flexibility gained with the introduction of programmable, electronic cockpit displays in the 1980s must be exploited to the full extent. An important candidate to become the primary flight display of future flight decks is the tunnel-in-the-sky display, a perspective flight-path display that shows the reference trajectory to be flown in a synthetic three-dimensional world. The usefulness of the tunnel display in the pilot manual aircraft control task is the subject of this thesis. The mainstream of tunnel display research is confined to empirical comparisons of the tunnel display with conventional displays. The approach taken in the present theoretical and experimental study is original and new as it is conducted from the perspective of cybernetics. A four-stage methodology is developed to study the fundamental characteristics of pilot/display interaction, based on a theoretical analysis of information, in particular the information used for control. The information analysis is conducted within the context of Gibson's ecological approach to visual perception. The information analysis provides novel insights into how the tunnel display geometric design variables can affect pilot behavior. To examine the validity of the theoretical hypotheses, six experiments have been conducted. Three experiments examined the effects of manipulating some of the main display design variables, such as the tunnel size, the viewing volume and the presence of guidance symbology. Another three experiments investigated the fundamental characteristics of the tunnel geometrical design in the tasks of following a trajectory that is either straight or circular, and in the task of conducting a curve-interception maneuver. The experiments show that the cybernetic, information-centered approach is indeed very successful in pin-pointing the important characteristics of pilot/display interaction. The experimental methodology employed in this thesis aimed at integrating the model-based approach with the common approach of collecting mainly performance-related data. It is described in detail how experiments can be designed with the objective of conducting a control-theoretic analysis. The limitations of some non-parametric identification methods in multi-axis, multiple loop tracking tasks are described. The use of criterion functions, in both the frequency and the time domain, in the parametric identification methods is also exemplified.Aerospace Engineerin

Tracking curved trajectories with a tunnel-in-the-sky display

Aerospace Engineerin

Modelling manual control of straight trajectories with a perspective flight-path display

Aerospace Engineerin

Towards a control-theoretic model of pilot manual control behaviour with a perspective flight-path display

Aerospace Engineerin

Haptic gas pedal feedback for active car-following support

The research presented in this dissertation focuses on supporting drivers in the longitudinal control of their vehicle during car-following. The goal of the research is the human-centred development of a haptic gas pedal interface that comfortably supports drivers in maintaining a safe separation with a leading vehicle during car-following. Two different approaches were found to be suitable for implementation as haptic information providers through the gas pedal. The first approach was to add a force to the gas pedal dynamics which would have to be related to the safe-field-of-travel ahead of the own vehicle and changes therein. The gas pedal dynamics, that is, the force/pedal-position relationship is not changed by this approach. The second approach was to change the stiffness of the gas pedal by adding a virtual stiffness to the inherent stiffness of the gas pedal. By doing so, the dynamics of the gas pedal are changed depending on the changes detected in the safe-field-of-travel. In both approaches, an electrical actuator provides the additional force or stiffness. The main hypothesis of this dissertation is the assumption that with the appropriate haptic feedback of longitudinal traffic information drivers will adopt a force-task in controlling the haptic gas pedal. Experimental verification leads to the conclusion that the stiffness feedback design with time-to-contact information scaled by time headway performs best in this respect.Aerospace Engineerin

Aerospace human-machine systems: From safety to where?

Aerospace Engineerin

Displays, perception and aircraft control: A survey of theory and modelling of pilot behaviour with spatial instruments

Aerospace Engineerin

Experimental studies on heat transfer in thermo-magnetic onvection for para- and diamagnetic fluids

In industrial heat transfer processes, natural convection enters in various forms. One form of natural convection is thermo-magnetic convection. Besides gravitational force, magnetic force causes warmer fluid to rise or fall dependent on the fluids magnetic susceptibility and direction of magnetic field gradient. Magnetic susceptibility is a material property which indicates a degree of magnetization in a material. For paramagnetic fluids magnetic susceptibility depends on temperature, is positive and therefore attracted by magnetic field. Magnetic susceptibility of diamagnetic materials is independent on temperature, is negative and hence repelled by magnetic field. Magnetic force can be used to enhance or suppress gravity. This phenomena is widely investigated for many materials, magnetic field strengths and set-up geometries. In this research thermo-magnetic convection and the effect it has on internal heat transfer is experimentally investigated for para- diamagnetic fluids. Making use of a 10 Tesla superconducting magnet, which can generate field gradients up to 870 T2/m, steady, oscillating and turbulent flow regimes can be observed. I performed the experiments at the AGH University of Science and Technology in Krakow, Poland. A small cubical enclosure filled with para- or diamagnetic fluid is placed at different positions in the magnet to get enhancement or suppression of internal heat transfer. Enclosure is heated from below and top is kept at constant temperature. Temperature of the fluid is measured with thermocouples at six different positions inside the enclosure. From these temperature-time measurements a power spectrumis obtained to determine the characteristic flow regime. Internal heat transfer is investigated by measuring different variables and calculate thermo-magnetic Rayleigh and Nusselt numbers. As paramagnetic fluid a 40% water-glycerol solution is used and gadoliniumnitrate is added to create a higher magnetic susceptibility. Enclosure was placed above the magnet centre which should give a magnetic force that enhances gravitational buoyancy. Temperature difference between the hot and cold plate of the enclosure is 5 and 11±C, respectively case G5A and G11A. Case G5A shows transition in the flow regime from steady to oscillating to turbulent with increasing of magnetic field. Case G11A shows turbulent regime for each measurement. Nusselt number calculations for glycerol solution measurements show an increase, up to 2.5 times, in internal heat transfer. Turbulence causes better mixing and hence better heat transfer. Relation between RaTM and Nu are compared with previous (experimental) relations and show good agreement. Pure water is used as diamagnetic fluid. First enclosure is placed below magnet centre and temperature difference is 5 and 1 ±C, respectively case W5B and W1B. Here magnetic force should enhance internal heat transfer. Case W5A and W3A are measured above the magnet centre and have respectively a temperature difference of 5 and 3 ±C. Case W5B and W5A both show turbulent flow regime for all measurements. Internal heat transfer is about the same for both cases but show a slight increase for W5B and decrease for W5A. There can be concluded that for turbulent flow regimes magnetic force direction has no significant influence on internal heat transfer. For smaller temperature differences, case W1B and W3A, magnetic force does influence measurements. CaseW1B shows steady flow regime first and for higher magnetic field strengths fluid plumes start to rise and sink due to magnetic force. Case W3A shows a very clear transition from turbulence to oscillating flow. Small temperature differences cause large measurement errors and internal heat transfer is assumed to be constant. Recommendations for further research is to get a better impression of fluid structures and temperatures in the enclosure. Fluid behaviour can be visualized with liquid crystals and velocity fields can be determined by using PIV on these visualizations. The velocities can be compared to simulations. To get realistic simulations, fluid properties need to be measured for different temperatures and if necessary differentmagnetic field strengths.Transport PhenomenaChemical EngineeringApplied Science