Thomas A. Seder

Where should i turn: moving from individual to collaborative navigation strategies to inform the interaction design of future navigation systems

The design of in-vehicle navigation systems fails to take into account the social nature of driving and automobile navigation. In this paper, we consider navigation as a social activity among drivers and navigators to improve design of such systems. We explore the implications of moving from a map-centered, individually-focused design paradigm to one based upon collaborative human interaction during the navigation task. We conducted a qualitative interaction design study of navigation among three types of teams: parents and their teenage children, couples, and unacquainted individuals. We found that collaboration varied among these different teams, and was influenced by social role, as well as the task role of driver or navigator. We also found that patterns of prompts, maneuvers, and confirmations varied among the three teams. We identify overarching practices that differ greatly from the literature on individual navigation. From these discoveries, we present design implications that can be used to inform future navigation systems.

A prototype of landmark-based car navigation using a full-windshield head-up display system

In driving applications, a full windshield head-up display (FWD) system provides a flexible way for delivering driving related information. The projected information (text, image and graphics) is distorted on the car windshield because of its non-planar surface, the FWD projectors position and the viewing angle of the driver. In this paper, we present development of a prototype of landmark-based car navigation using an FWD system. We propose to use a computer vision method to automatically correct FWD projection distortion on the windshield. Our system consists of an FWD, a camera and an LCD video projector. In the calibration phase, the camera captures the patterns projected by the FWD projector and our method automatically models the windshield distortion. In the working phase, the LCD video projector projects a video sequence (that is captured on a moving vehicle in the real driving situation) onto a wall to simulate real driving and the camera simulates the drivers view. Our system aims to detect and highlight key landmarks such as road signs on the windshield by controlling the FWD projector to provide better navigation information. We demonstrate the proposed concept using our previously developed street landmark detection system.

Temperature measurements in a laser-heated gas by quantitative shadowgraphy

A whole-field quantitative shadow method was used to determine the temperature in a laser ignition experiment. An ethylene-air mixture was heated by a CO(2) laser, and the hot gas was illuminated with a collimated laser beam. The resulting shadow image was recorded digitally and analyzed to determine the temperature. Very good spatial and temporal resolutions (15 microm and 10 ns) were achieved using a simple optical arrangement. A computer simulation was used to determine the sensitivity of the shadow temperatures to blurring due to diffraction and uncertainties in parameters such as the ambient pressure. Temperatures determined from Rayleigh light scattering agreed with the shadow measurements to within 1-4%.