Tactile Perception And Visuotactile Integration For Robotic Exploration

As the close perceptual sibling of vision, the sense of touch has historically received less than deserved attention in both human psychology and robotics. In robotics, this may be attributed to at least two reasons. First, it suffers from the vicious cycle of immature sensor technology, which causes industry demand to be low, and then there is even less incentive to make existing sensors in research labs easy to manufacture and marketable. Second, the situation stems from a fear of making contact with the environment, avoided in every way so that visually perceived states do not change before a carefully estimated and ballistically executed physical interaction. Fortunately, the latter viewpoint is starting to change. Work in interactive perception and contact-rich manipulation are on the rise. Good reasons are steering the manipulation and locomotion communities’ attention towards deliberate physical interaction with the environment prior to, during, and after a task. We approach the problem of perception prior to manipulation, using the sense of touch, for the purpose of understanding the surroundings of an autonomous robot. The overwhelming majority of work in perception for manipulation is based on vision. While vision is a fast and global modality, it is insufficient as the sole modality, especially in environments where the ambient light or the objects therein do not lend themselves to vision, such as in darkness, smoky or dusty rooms in search and rescue, underwater, transparent and reflective objects, and retrieving items inside a bag. Even in normal lighting conditions, during a manipulation task, the target object and fingers are usually occluded from view by the gripper. Moreover, vision-based grasp planners, typically trained in simulation, often make errors that cannot be foreseen until contact. As a step towards addressing these problems, we present first a global shape-based feature descriptor for object recognition using non-prehensile tactile probing alone. Then, we investigate in making the tactile modality, local and slow by nature, more efficient for the task by predicting the most cost-effective moves using active exploration. To combine the local and physical advantages of touch and the fast and global advantages of vision, we propose and evaluate a learning-based method for visuotactile integration for grasping

Holistic and Analytic Representations' of Ignored and Attended Objects

Attended images prime both themselves and their left-right reflections, whereas ignored images prime themselves but not their reflections (Stankiewicz, Hummel, & Cooper, 1998). These and other effects are predicted by the hybrid theory of object recognition (Hummel & Stankiewicz, 1996a) that the human visual system represents ignored images holistically (i.e., view-based), and attended images both holistically and analytically (i.e., part-based). In nine experiments using a naming task the predictions of the model were tested with split, plane-rotated and depth-rotated views of common objects. Consistent with the prediction of the hybrid theory, Experiments 1 and 3 demonstrated that split images primed their intact and split counterparts when they were attended but not when they were ignored, whereas intact images primed themselves whether they were attended or not. Experiment 2 demonstrated that a substantial component of the observed priming for attended split images was specifically visual. In Experiment 5, attended images primed themselves and their plane-rotated versions (90°) whereas ignored images only primed themselves but not their rotated versions. Experiment 6 tested whether rotated objects with a definite upright orientation prime themselves in the same view. Substantial priming was observed for attended and ignored objects when shown in their upright view. However, rotated objects with a definite upright orientation primed themselves only when attended but not when ignored. This result indicates that ignored images make contact with stored representations. Experiment 7 replicated the findings of Stankiewicz et al. for mirror images but with grey-level rendered 3D images. Experiment 8 tested priming for these objects using orientations in which parts change from study to test view. As before, there was substantial priming in all but the ignored-rotated condition. However, there was a greater reduction in priming for attended rotated objects than for ignored rotated objects. This result indicates that the representations mediating recognition of attended images are specifically sensitive to part changes. In Experiment 9, objects were rotated in depth such that equivalent parts were visible in both views. As in Experiment 7, the priming effects of view and attention were additive. These data provide strong evidence that one function of visual attention is to permit the generation of analytic (i.e., part-based) representations of object shape. At the same time these results show that object recognition is also mediated by additional holistic representations

Boundary contour based surface representation.

We receive most information about our surrounding space and objects through the eyes. To reconstruct the 3D space and objects in the visual system from the 2D retinal images, surface representation must be a critical intermediate stage in the visual processing stream. It is hypothesized in the dissertation that the visual system represents textured surface by a border-to-interior strategy: boundary contours would be encoded first and then border-ownership assignments would be resolved. This process would solve the related problems such as figure-ground segregation, surface depth relationship, occlusion, transparency, etc. As a result, the boundary contours of the surfaces would be well defined and then the visual system could register the local features in different domains with the boundary contours, gradually from the adjacent areas of the boundary contours to the interior of the surfaces. To testify this hypothesis in the current proposal, a monocular boundary contour (MBC) paradigm is adapted from earlier studies by Ooi and He (2005, 2006). In Chapter 1, the boundary-contour-based hypothesis, with the MBC paradigm, is used to re-address a decade-long debate about binocular vision: whether (and how) binocular integration and inhibition coexist. In Chapter 2–5, the MBC-induced binocular suppression is systematically investigated, especially in Chapter 3 where the cortical speed of the hypothesized border-to-interior spreading is quantitatively estimated. In the end, the rules how the surface fragments are integrated to a global representation is further studied in Chapter 6 and 7, especially focusing on the role of luminance and color contrast polarities

How sketches work: a cognitive theory for improved system design

Evidence is presented that in the early stages of design or composition the mental processes used by artists for visual invention require a different type of support from those used for visualising a nearly complete object. Most research into machine visualisation has as its goal the production of realistic images which simulate the light pattern presented to the retina by real objects. In contrast sketch attributes preserve the results of cognitive processing which can be used interactively to amplify visual thought. The traditional attributes of sketches include many types of indeterminacy which may reflect the artist's need to be "vague". Drawing on contemporary theories of visual cognition and neuroscience this study discusses in detail the evidence for the following functions which are better served by rough sketches than by the very realistic imagery favoured in machine visualising systems. 1. Sketches are intermediate representational types which facilitate the mental translation between descriptive and depictive modes of representing visual thought. 2. Sketch attributes exploit automatic processes of perceptual retrieval and object recognition to improve the availability of tacit knowledge for visual invention. 3. Sketches are percept-image hybrids. The incomplete physical attributes of sketches elicit and stabilise a stream of super-imposed mental images which amplify inventive thought. 4. By segregating and isolating meaningful components of visual experience, sketches may assist the user to attend selectively to a limited part of a visual task, freeing otherwise over-loaded cognitive resources for visual thought. 5. Sequences of sketches and sketching acts support the short term episodic memory for cognitive actions. This assists creativity, providing voluntary control over highly practised mental processes which can otherwise become stereotyped. An attempt is made to unite the five hypothetical functions. Drawing on the Baddeley and Hitch model of working memory, it is speculated that the five functions may be related to a limited capacity monitoring mechanism which makes tacit visual knowledge explicitly available for conscious control and manipulation. It is suggested that the resources available to the human brain for imagining nonexistent objects are a cultural adaptation of visual mechanisms which evolved in early hominids for responding to confusing or incomplete stimuli from immediately present objects and events. Sketches are cultural inventions which artificially mimic aspects of such stimuli in order to capture these shared resources for the different purpose of imagining objects which do not yet exist. Finally the implications of the theory for the design of improved machine systems is discussed. The untidy attributes of traditional sketches are revealed to include cultural inventions which serve subtle cognitive functions. However traditional media have many short-comings which it should be possible to correct with new technology. Existing machine systems for sketching tend to imitate nonselectively the media bound properties of sketches without regard to the functions they serve. This may prove to be a mistake. It is concluded that new system designs are needed in which meaningfully structured data and specialised imagery amplify without interference or replacement the impressive but limited creative resources of the visual brain

Twilight of the Anthropocene idols

Following on from Theory and the Disappearing Future, Cohen, Colebrook and Miller turn their attention to the eco-critical and environmental humanities’ newest and most fashionable of concepts, the Anthropocene. The question that has escaped focus, as “tipping points” are acknowledged as passed, is how language, mnemo-technologies, and the epistemology of tropes appear to guide the accelerating ecocide, and how that implies a mutation within reading itself—from the era of extinction events.Only in this moment of seeming finality, the authors argue, does there arise an opportunity to be done with mourning and begin reading. Drawing freely on Paul de Man’s theory of reading, anthropomorphism and the sublime, Twilight of the Anthropocene Idols argues for a mode of critical activism liberated from all-too-human joys and anxieties regarding the future. It was quite a few decades ago (1983) that Jurgen Habermas declared that ‘master thinkers had fallen on hard times.’ His pronouncement of hard times was premature. For master thinkers it is the best of times. Not only is the world, supposedly, falling into a complete absence of care, thought and frugality, a few hyper-masters have emerged to tell us that these hard times should be the best of times. It is precisely because we face the end that we should embrace our power to geo-engineer, stage the revolution, return to profound thinking, reinvent the subject, and recognize ourselves fully as one global humanity. Enter anthropos

Reference Object Choice in Spatial Language: Machine and Human Models

The thesis underpinning this study is as follows; it is possible to build machine models that are indistinguishable from the mental models used by humans to generate language to describe their environment. This is to say that the machine model should perform in such a way that a human listener could not discern whether a description of a scene was generated by a human or by the machine model. Many linguistic processes are used to generate even simple scene descriptions and developing machine models of all of them is beyond the scope of this study. The goal of this study is, therefore, to model a sufficient part of the scene description process, operating in a sufficiently realistic environment, so that the likelihood of being able to build machine models of the remaining processes, operating in the real world, can be established. The relatively under-researched process of reference object selection is chosen as the focus of this study. A reference object is, for instance, the `table' in the phrase ``The flowers are on the table''. This study demonstrates that the reference selection process is of similar complexity to others involved in generating scene descriptions which include: assigning prepositions, selecting reference frames and disambiguating objects (usually termed `generating referring expressions'). The secondary thesis of this study is therefore; it is possible to build a machine model that is indistinguishable from the mental models used by humans in selecting reference objects. Most of the practical work in the study is aimed at establishing this. An environment sufficiently near to the real-world for the machine models to operate on is developed as part of this study. It consists of a series of 3-dimensional scenes containing multiple objects that are recognisable to humans and `readable' by the machine models. The rationale for this approach is discussed. The performance of human subjects in describing this environment is evaluated, and measures by which the human performance can be compared to the performance of the machine models are discussed. The machine models used in the study are variants on Bayesian networks. A new approach to learning the structure of a subset of Bayesian networks is presented. Simple existing Bayesian classifiers such as naive or tree augmented naive networks did not perform sufficiently well. A significant result of this study is that useful machine models for reference object choice are of such complexity that a machine learning approach is required. Earlier proposals based on sum-of weighted-factors or similar constructions will not produce satisfactory models. Two differently derived sets of variables are used and compared in this study. Firstly variables derived from the basic geometry of the scene and the properties of objects are used. Models built from these variables match the choice of reference of a group of humans some 73\% of the time, as compared with 90\% for the median human subject. Secondly variables derived from `ray casting' the scene are used. Ray cast variables performed much worse than anticipated, suggesting that humans use object knowledge as well as immediate perception in the reference choice task. Models combining geometric and ray-cast variables match the choice of reference of the group of humans some 76\% of the time. Although niether of these machine models are likely to be indistinguishable from a human, the reference choices are rarely, if ever, entirely ridiculous. A secondary goal of the study is to contribute to the understanding of the process by which humans select reference objects. Several statistically significant results concerning the necessary complexity of the human models and the nature of the variables within them are established. Problems that remain with both the representation of the near-real-world environment and the Bayesian models and variables used within them are detailed. While these problems cast some doubt on the results it is argued that solving these problems is possible and would, on balance, lead to improved performance of the machine models. This further supports the assertion that machine models producing reference choices indistinguishable from those of humans are possible

Graphic Legibility Enhancement using Simplification Guidelines

This study explores an approach to app icon legibility enhancement. Four areas of research are included: (1) design process; (2) the trend of logo/app icon redesign; (3) graphic legibility and (4) graphic simplification. It presents the results of five experiments designed to capture and compare design principles. Firstly, the result categorised the characteristics of simple shape. Secondly, the agreement of simplification judgement was summarised based on the average score of participants. Thirdly, the impact of each simplification criterion was compared and represented as a ratio; a measurement template and simplification guidelines were also generated at this stage. Fourthly, how this design principle (simplification guidelines) can be applied in practical use by student designers was examined. Finally, the legibility enhancement test was proved by the results of reaction time and accuracy improvement. The findings of this study determined the impact of simplification criteria with regard to: component, open-closed, weight, form, symmetry, angles and straight-curved respectively. After identifying these design principles (simplification guidelines), graphic designers, user interface designers and other users will be enabled to design a more legible logo/app icon design required for display on small devices

Proceedings of the NASA Conference on Space Telerobotics, volume 3

The theme of the Conference was man-machine collaboration in space. The Conference provided a forum for researchers and engineers to exchange ideas on the research and development required for application of telerobotics technology to the space systems planned for the 1990s and beyond. The Conference: (1) provided a view of current NASA telerobotic research and development; (2) stimulated technical exchange on man-machine systems, manipulator control, machine sensing, machine intelligence, concurrent computation, and system architectures; and (3) identified important unsolved problems of current interest which can be dealt with by future research

Activity in area V3A predicts positions of moving objects

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The attentive robot companion: learning spatial information from observation and verbal interaction

Ziegler L. The attentive robot companion: learning spatial information from observation and verbal interaction. Bielefeld: Universität Bielefeld; 2015.This doctoral thesis investigates how a robot companion can gain a certain degree of situational awareness through observation and interaction with its surroundings. The focus lies on the representation of the spatial knowledge gathered constantly over time in an indoor environment. However, from the background of research on an interactive service robot, methods for deployment in inference and verbal communication tasks are presented. The design and application of the models are guided by the requirements of referential communication. The approach here involves the analysis of the dynamic properties of structures in the robot’s field of view allowing it to distinguish objects of interest from other agents and background structures. The use of multiple persistent models representing these dynamic properties enables the robot to track changes in multiple scenes over time to establish spatial and temporal references. This work includes building a coherent representation considering allocentric and egocentric aspects of spatial knowledge for these models. Spatial analysis is extended with a semantic interpretation of objects and regions. This top-down approach for generating additional context information enhances the grounding process in communication. A holistic, boosting-based classification approach using a wide range of 2D and 3D visual features anchored in the spatial representation allows the system to identify room types. The process of grounding referential descriptions from a human interlocutor in the spatial representation is evaluated through referencing furniture. This method uses a probabilistic network for handling ambiguities in the descriptions and employs a strategy for resolving conflicts. In order to approve the real-world applicability of these approaches, this system was deployed on the mobile robot BIRON in a realistic apartment scenario involving observation and verbal interaction with an interlocutor