Robust visual servoing in 3d reaching tasks

This paper describes a novel approach to the problem of reaching an object in space under visual guidance. The approach is characterized by a great robustness to calibration errors, such that virtually no calibration is required. Servoing is based on binocular vision: a continuous measure of the end-effector motion field, derived from real-time computation of the binocular optical flow over the stereo images, is compared with the actual position of the target and the relative error in the end-effector trajectory is continuously corrected. The paper outlines the general framework of the approach, shows how visual measures are obtained and discusses the synthesis of the controller along with its stability analysis. Real-time experiments are presented to show the applicability of the approach in real 3-D applications

The Whole World in Your Hand: Active and Interactive Segmentation

Object segmentation is a fundamental problem in computer vision and a powerful resource for development. This paper presents three embodied approaches to the visual segmentation of objects. Each approach to segmentation is aided by the presence of a hand or arm in the proximity of the object to be segmented. The first approach is suitable for a robotic system, where the robot can use its arm to evoke object motion. The second method operates on a wearable system, viewing the world from a human's perspective, with instrumentation to help detect and segment objects that are held in the wearer's hand. The third method operates when observing a human teacher, locating periodic motion (finger/arm/object waving or tapping) and using it as a seed for segmentation. We show that object segmentation can serve as a key resource for development by demonstrating methods that exploit high-quality object segmentations to develop both low-level vision capabilities (specialized feature detectors) and high-level vision capabilities (object recognition and localization)

Active Vision for Scene Understanding

Visual perception is one of the most important sources of information for both humans and robots. A particular challenge is the acquisition and interpretation of complex unstructured scenes. This work contributes to active vision for humanoid robots. A semantic model of the scene is created, which is extended by successively changing the robot\u27s view in order to explore interaction possibilities of the scene

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 386)

This bibliography lists 117 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during Mar. 1994. Subject coverage includes: aerospace medicine and physiology, life support systems and man/system technology, protective clothing, exobiology and extraterrestrial life, planetary biology, and flight crew behavior and performance

Upright posture and the meaning of meronymy: A synthesis of metaphoric and analytic accounts

Cross-linguistic strategies for mapping lexical and spatial relations from body partonym systems to external object meronymies (as in English ‘table leg’, ‘mountain face’) have attracted substantial research and debate over the past three decades. Due to the systematic mappings, lexical productivity and geometric complexities of body-based meronymies found in many Mesoamerican languages, the region has become focal for these discussions, prominently including contrastive accounts of the phenomenon in Zapotec and Tzeltal, leading researchers to question whether such systems should be explained as global metaphorical mappings from bodily source to target holonym or as vector mappings of shape and axis generated “algorithmically”. I propose a synthesis of these accounts in this paper by drawing on the species-specific cognitive affordances of human upright posture grounded in the reorganization of the anatomical planes, with a special emphasis on antisymmetrical relations that emerge between arm-leg and face-groin antinomies cross-culturally. Whereas Levinson argues that the internal geometry of objects “stripped of their bodily associations” (1994: 821) is sufficient to account for Tzeltal meronymy, making metaphorical explanations entirely unnecessary, I propose a more powerful, elegant explanation of Tzeltal meronymic mapping that affirms both the geometric-analytic and the global-metaphorical nature of Tzeltal meaning construal. I do this by demonstrating that the “algorithm” in question arises from the phenomenology of movement and correlative body memories—an experiential ground which generates a culturally selected pair of inverse contrastive paradigm sets with marked and unmarked membership emerging antithetically relative to the transverse anatomical plane. These relations are then selected diagrammatically for the classification of object orientations according to systematic geometric iconicities. Results not only serve to clarify the case in question but also point to the relatively untapped potential that upright posture holds for theorizing the emergence of human cognition, highlighting in the process the nature, origins and theoretical validity of markedness and double scope conceptual integration

Science Fiction

Science fiction (SF) emerges as a distinct literary and cultural genre out of a familiar set of world-famous texts ranging from Mary Shelley’s Frankenstein (1818) to Gene Roddenberry’s Star Trek (1966–) to the Marvel Cinematic Universe (2008–) that have, in aggregate, generated a colossal, communal archive of alternate worlds and possible future histories. SF’s dialectical interplay between utopian optimism and apocalyptic pessimism can be felt across the genre’s now centuries-long history, only intensifying in the 20th century as the clash between humankind’s growing technological capabilities and its ability to use those powers safely or wisely has reached existential-threat propositions, not simply for human beings but for all life on the planet. In the early 21st century, as in earlier cultural moments, the writers and critics of SF use the genre’s articulation of different societies and different possible futures as the occasion to reflect on our own present, in ways that range from full-throated defense of the status quo to the ruthless denunciation of all institutions that currently exist in the name of some other, better world. SF’s global popularity has grown to the point where it now looms quite large over cultural production generally, becoming arguably the most popular narrative genre in existence, particularly in the sorts of SF action spectacles that have dominated the global box office of the first two decades of the 21st century. It has also become increasingly difficult to tell the difference between the things we used to think of as SF and the advanced communication, transportation, and entertainment technologies that have become so ubiquitous and familiar that we now take them for granted, as well as the growing prevalence of political, economic, and ecological crises now erupting out of the pages of our science fictions, like our very worst dreams come to life

An investigation into the efficacy of technical illustrations depicting physical orientation in sports procedures

This study on mental imagery set out to investigate the efficacy of technical illustrations depicting physical orientation in sports procedures. The study was carried out by junior level students on an undergraduate degree in computer science at a Japanese technical university with no specialized knowledge of information design or visual communication. The study participants were asked to match body and overhead images shown from different height perspectives (waist and chest height) and camera positions (front, 1/3rd side, side, 1/3rd back, back) of a man holding a bat and a man hitting with a bat. These physical actions were selected by the researchers as they can typically be seen in multiple sports such as baseball, rounders or cricket, thus widening the potential applicability of the study findings. Overall, the study participants achieved relatively high levels of accuracy in matching the body and overhead images and no consistent or clear pattern emerged with regard to preferred height perspectives or camera positions. However, what can be suggested is that the study participants appeared to prefer - and the mean accuracy levels were higher for - viewpoints shown into the display plane. In addition, the study participants self-reported relatively high overall confidence in their matches despite not having any specialised knowledge of visual communication. It is hoped that this study and accompanying literature review could help technical communicators in thinking about how to design 2D technical illustrations and contribute to existing research into information design and visual communication, particularly in a sporting context

A Dataset of Gaze Behavior in VR Faithful to Natural Statistics

Eye tracking technology is advancing swiftly and many areas of research have begun taking advantage of this. Existing eye trackers project gaze onto a 2D plane, whether it be the display of a head mounted virtual reality (VR) helmet or an image of a real life scene the user is in. This allows us to easily analyze what a viewer is looking at, but limits classification of gaze behaviors from this type of signal. Instead, a system that takes into account head movements within the same space as gaze velocity allows researchers to classify more advanced gaze behaviors such as smooth pursuits and fixations resulting from vestibulo-ocular reflex. For this work data is collected in real world environments where head and gaze movements are recorded over a variety of tasks. The resulting data is then used to construct a distribution of naturally occurring gaze behaviors. This distribution is then used to drive a VR data collection experiment that elicits specific gaze behaviors such as fixations and saccades with specific velocities and directions. A dataset of 12 subjects was collected while subjects play a shooting game in the virtual world. Data was analyzed to see if the intended eye movements were produced, and also to compare the eye movements that occur in fast versus slow presentation of targets