International Journal of Advanced Robotic Systems
Volume 2 Number 4 December 2005 |
Guest Editorial Interview with Dr. Ulrich Nehmzow
Abstract: Due to ultraviolet flux in the surface layers of most solar bodies, future astrobiological research is increasingly seeking to conduct subsurface penetration and drilling to detect chemical signature for extant or extinct life. To address this issue, we present a micro-penetrator concept (mass < 10 kg) that is suited for extraterrestrial planetary deployment and in situ investigation of chemical and physical properties. The instrumentation in this concept is a bio-inspired drill to access material beneath sterile surface layer for biomarker detection. The proposed drill represents a novel concept of two-valve-reciprocating motion, inspired by the working mechanism of wood wasp ovipositors. It is lightweight (0.5 kg), driven at low power (3 W), and able to drill deep (1-2 m). Tests have shown that the reciprocating drill is feasible and has potential of improving drill efficiency without using any external force. The overall penetration system provides a small, light and energy efficient solution to in situ astrobiological studies, which is crucial for space engineering. Such a micro-penetrator can be used for exploration of terrestrial-type planets or other small bodies of the solar system with the minimum of modifications.
Abstract: In this paper we present a strategy for the problem of exploring an unknown 2D environment. Existing techniques can be methodical, goal oriented or non-reactive to additional knowledge received at each new viewpoint. We present an approach which is not goal driven, but rather seeks new unseen areas to view and explore. The novelty of the strategy presented is the use of a view-improvement technique along with an optimal viewpoint planning method for the calculation and selection of the next-best-viewpoint. The strategy is designed for a sensor system with a limited field-of-view. Example explorations are presented and we demonstrate that the strategy finds new areas to view without exhaustive searching.
EcoBot-II: An artificial agent with a natural metabolism, Page 295-300 Abstract: In this paper we report the development of the robot EcoBot-II, which exhibits a primitive form of artificial symbiosis. Microbial Fuel Cells (MFCs) were used as the onboard energy supply, which consisted of bacterial cultures from sewage sludge and employed oxygen from free air for oxidation at the cathode. EcoBot-II was able to perform sensing, information processing, communication and actuation when fed (amongst other substrates) with flies. This is the first robot in the world, to utilise unrefined substrate, oxygen from free air and exhibit four different types of behaviour.
Perceptual Perspective Taking and Action Recognition, Page 301-308 Abstract: Robots that operate in social environments need to be able to recognise and understand the actions of other robots, and humans, in order to facilitate learning through imitation and collaboration. The success of the simulation theory approach to action recognition and imitation relies on the ability to take the perspective of other people, so as to generate simulated actions from their point of view. In this paper, simulation of visual perception is used to recreate the visual egocentric sensory space and egocentric behaviour space of an observed agent, and through this increase the accuracy of action recognition. To demonstrate the approach, experiments are performed with a robot attributing perceptions to and recognising the actions of a second robot.
Control of Open Contour Formations of Autonomous Underwater Vehicles, Page 309-316 Abstract: In this paper, we propose a distributed elastic behaviour for a deformable chain-like formation of small autonomous underwater vehicles with the task of forming special shapes which have been explicitly defined or are defined by some iso-contour of an environmental concentration field. In the latter case, the formation has to move in such a way as to meet certain formation parameters as well as adapt to the iso-line. We base our controller on our previous models (for manually controlled end points) using general curve evolution theory but will also propose appropriate motions for the end robots of an open chain.
Task Characterisation and Cross-Platform Programming Through System Identification, Page 317-324
Psychologically Inspired Sensory-Motor Development in Early Robot Learning, Page 325-333 Abstract: We present an implementation of a model of very early sensory-motor development, guided by results from developmental psychology. Behavioural acquisition and growth is demon-strated through constraint-lifting mechanisms initiated by global state variables. The results show how staged competence can be shaped by qualitative behaviour changes produced by anatomical, computational and maturational constraints.
A Biomimetic Haptic Sensor, Page 335-343 Abstract: The design and implementation of the periphery of an artificial whisker sensory system is presented. It has been developed by adopting a biomimetic approach to model the structure and function of rodent facial vibrissae. The artificial vibrissae have been formed using composite materials and have the ability to be actively moved or whisked. The sensory structures at the root of real vibrissae has been modelled and implemented using micro strain gauges and Digital Signal Processors. The primary afierents and vibrissal trigeminal ganglion have been modelled using empirical data taken from electrophysiological measurements, and implemented in real-time using a Field Programmable Gate Array. Pipelining techniques were employed to maximise the utility of the FPGA hardware. The system is to be integrated into a more complete whisker sensory model, including neural structures within the central nervous system, which can be used to orient a mobile robot.
Discussion of Exemplary Metrics for Multi-Robot Systems for Formation Navigation, Page 345-353 Abstract: This work addresses the problem of metrics for multi-robot systems. It is often desirable to compare different strategies or algorithms for similar problems, e.g. mapping or localization. Since these are often real time applications, classical criterions like time or space complexity are not very helpful. Several other metrics have been suggested. In this paperformation navigation is used as an example application. Possible metrics are presented and discussed, and two of them are used to exemplarily evaluate the results of several formation experiments. Problems and drawbacks of these metrics are discussed and preconditions for a general metricfor the formation problem are adumbrated. Finally, first steps towards a generic and generally applicable metric are presented by means of simulation experiments.
Automated Exploration and Inspection: Comparing Two Visual Novelty Detectors, Page 355-362 Abstract: Mobile robot applications that involve exploration and inspection of dynamic environments benefit, and often even are dependant on reliable novelty detection algorithms. In this paper we compare and discuss the performance and functionality of two different on-line novelty detection algorithms, one based on incremental Principal Component Analysis and the other on a Grow-When-Required artificial neural network. A series of experiments using visual input obtained by a mobile robot interacting with laboratory and real-world environments demonstrate and measure advantages and disadvantages of each approach.
On Formal Specification of Emergent Behaviours in Swarm Robotic Systems, Page 363-370 Abstract: It is a characteristic of swarm robotics that specifying overall emergent swarm behaviours in terms of the low-level behaviours of individual robots is very dificult. Yet if swarm robotics is to make the transition from the laboratory to real-world engineering realisation we need such specifications. This paper explores the use of temporal logic to formally specify, and possibly also prove, the emergent behaviours of a robotic swarm. The paper makes use of a simplified wireless connected swarm as a case study with which to illustrate the approach. Such a formal approach could be an important step toward a disciplined design methodology for swarm robotics.
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ARS Web 2005 |