BEES: exploring Mars with bioinspired technologies

The bioinspired engineering of exploration systems (BEES) applies insects' biological sensory and flight control abilities to the design of real-time autonomous, visual-navigation and control systems for small unmanned flying vehicles. The bioinspired engineering of exploration systems focuses on using the variety of nature-tested mechanisms successfully implemented by biological organisms but not easily accomplished by conventional methods. We apply BEES technology to the development of bioinspired visual navigation sensors integrated on small flyers to enable autonomous flight. BEES technology extracts the salient principles from a variety of diverse organisms adept at flight, and applies them to machines that can fly on Mars.     

Induction of Fos-like immunoreactivity by opioids in guinea-pig brain

In the present study the effects of intracerebroventricular (i.c.v.) administration of 100 nmol of morphine, the selective mu-receptor agonist DAMGO, the delta-receptor agonist DPDPE and the kappa-receptor agonist U50,488H, on the induction of Fos-like immunoreactivity (Fos-LI) in the guinea-pig brain were investigated using immunohistochemical techniques. Guinea-pigs given i.c.v. injection of opioids showed marked increases in the number of Fos-LI nuclei within a large number of brain regions, several of which, including hypothalamic nuclei, paraventricular thalamic nucleus, the amygdala, periaqueductal gray, superior and inferior colliculi, the piriform and entorhinal cortices, have been shown to be activated under stressful or aversive conditions. Pretreatment with the opioid antagonist, naltrexone, before administration of morphine or U50,488H, inhibited Fos-LI induction indicating that the effects of the opioids were mediated by opioid receptors. U50,488H administration resulted in higher numbers of Fos-LI stained neurons compared to morphine in most regions other than the nucleus accumbens and interpeduncular nucleus. Morphine and DAMGO produced significantly higher numbers of Fos-LI neurons in the nucleus accumbens shell region than U50,488H, which may reflect the more powerful reinforcing/rewarding effects of mu-receptor agonists. Thus the present study supports a critical role for the nucleus accumbens shell region in the reinforcing/rewarding effects of opioids.     

Reflective surfaces for panoramic imaging

A family of reflective surfaces is presented that, when imaged by a camera, can capture a global view of the visual environment. By using these surfaces in conjunction with conventional imaging devices, it is possible to produce fields of view in excess of 180 degrees that are not affected by the distortions and aberrations found in refractive wide-angle imaging devices. By solving a differential equation expressing the camera viewing angle as a function of the angle of incidence on a reflective surface, a family of appropriate surfaces has been derived. The surfaces preserve a linear relationship between the angle of incidence of light onto the surface and the angle of reflection onto the imaging device, as does a normal mirror. However, the gradient of this linear relationship can be varied as desired to produce a larger or smaller field of view. The resulting family of surfaces has a number of applications in surveillance and machine vision.     

Catchment areas of panoramic snapshots in outdoor scenes

We took panoramic snapshots in outdoor scenes at regular intervals in two- or three-dimensional grids covering 1 m2 or 1 m3 and determined how the root mean square pixel differences between each of the images and a reference image acquired at one of the locations in the grid develop over distance from the reference position. We then asked whether the reference position can be pinpointed from a random starting position by moving the panoramic imaging device in such a way that the image differences relative to the reference image are minimized. We find that on time scales of minutes to hours, outdoor locations are accurately defined by a clear, sharp minimum in a smooth three-dimensional (3D) volume of image differences (the 3D difference function). 3D difference functions depend on the spatial-frequency content of natural scenes and on the spatial layout of objects therein. They become steeper in the vicinity of dominant objects. Their shape and smoothness, however, are affected by changes in illumination and shadows. The difference functions generated by rotation are similar in shape to those generated by translation, but their plateau values are higher. Rotational difference functions change little with distance from the reference location. Simple gradient descent methods are surprisingly successful in recovering a goal location, even if faced with transient changes in illumination. Our results show that view-based homing with panoramic images is in principle feasible in natural environments and does not require the identification of individual landmarks. We discuss the relevance of our findings to the study of robot and insect homing.     

Filtering and processing of panoramic images obtained using a camera and a wide-angle-imaging reflective surface

There is an increasing interest in wide-angle imaging of the environment using curved reflective surfaces. With this comes the need for appropriate filtering and processing of the acquired images. Here we present a technique for homogeneous, fast filtering of panoramic images captured using a camera and a wide-angle-imaging reflective surface. Imaging of the panoramic environment onto a two-dimensional (2-D) plane necessarily introduces spatial distortions such as stretching and bending that vary with the viewing direction. Therefore, if the panoramic image is to be filtered homogeneously in all viewing directions, it is necessary to match the filtering to the distortions. We show how this can be accomplished. The image acquired by the camera is first digitally unwarped and represented in Cartesian coordinates representing azimuth and elevation. The mappings of patches of uniform size and shape on the viewsphere are then established. Next, for each filter patch the local mappings of great circles along two principal axes (along the local longitudinal and elevational directions) on the image plane are determined. The mappings of these great circles are used to perform the 2-D convolution required by the filtering operation. Convolution along the directions of local, mutually orthogonal great circles permits the filtering to be carried out in a quasi-separable fashion, resulting in increased computational speed and efficiency. Examples of homogeneous filtering using this procedure are presented.     

Neural network-based optical flow versus traditional optical flow techniques with thermal aerial imaging in real-world settings

The study explores the feasibility of optical flow-based neural network from real-world thermal aerial imagery. While traditional optical flow techniques have shown adequate performance, sparse techniques do not work well during cold-soaked low-contrast conditions, and dense algorithms are more accurate in low-contrast conditions but suffer from the aperture problem in some scenes. On the other hand, optical flow from convolutional neural networks has demonstrated good performance with strong generalization from several synthetic public data set benchmarks. Ground truth was generated from real-world thermal data estimated with traditional dense optical flow techniques. The state-of-the-art Recurrent All-Pairs Field Transform for the Optical Flow model was trained with both color synthetic data and the captured real-world thermal data across various thermal contrast conditions. The results showed strong performance of the deep-learning network against established sparse and dense optical flow techniques in various environments and weather conditions, at the cost of higher computational demand.     

An efficient motion magnification system for real-time applications

The human eye cannot see subtle motion signals that fall outside human visual limits, due to either limited resolution of intensity variations or lack of sensitivity to lower spatial and temporal frequencies. Yet, these invisible signals can be highly informative when amplified to be observable by a human operator or an automatic machine vision system. Many video magnification techniques have recently been proposed to magnify and reveal these signals in videos and image sequences. Limitations, including noise level, video quality and long execution time, are associated with the existing video magnification techniques. Therefore, there is value in developing a new magnification method where these issues are the main consideration. This study presents a new magnification method that outperforms other magnification techniques in terms of noise removal, video quality at large magnification factor and execution time. The proposed method is compared with four methods, including Eulerian video magnification, phase-based video magnification, Riesz pyramid for fast phase-based video magnification and enhanced Eulerian video magnification. The experimental results demonstrate the superior performance of the proposed magnification method regarding all video quality metrics used. Our method is also 60–70% faster than Eulerian video magnification, whereas other competing methods take longer to execute than Eulerian video magnification.     

Review: The Benefits and Applications of Bioinspired Flight Capabilities

This paper addresses the challenges of flight on Mars that at this time have the same element of novelty as flight on Earth itself was a novelty in the Kitty Hawk era almost 100 years ago, details the scientific need for such flyers, highlights the bioinspired engineering of exploration systems (BEES) flyer development and finally describes a few viable mission architecture options that allow reliable data return from the BEES flyers using the limited telecom infrastructure that can be made available with a lander base to orbiter combination on Mars. Our recent developments using inspiration from biology that are enabling the pathway to demonstrate flight capability for Mars exploration are described. These developments hold substantial spin‐offs for a variety of applications both for NASA and DoD. Unmanned exploration to date suggests that Mars once had abundant liquid water (considered essential for life as we know it). It is not clear what transpired on the Martian climate to have turned the planet into the desert that it is today. Developing a comprehensive understanding of the past and present climatic events for Mars may provide important information relevant to the future of our own planet. Such exploration missions are enabled using the BEES technology. © 2003 Wiley Periodicals, Inc.     

Interactions of substance P with putative mediators of inflammation and ATP

Substance P has recently been localized in sensory nerves and has been suggested to be the mediator of antidromic vasodilatation. Interactions of substance P with putative mediators of inflammation and adenosine 5'-triphosphate were studied in rats using a quantitative Evans blue dye-leakage technique. Rats anaesthetized with either were given Evans blue. i.v. and intracutaneous injections of inflammatory agents were given into the shaved abdominal skin. Doses of substance P, 1-5 X 10(-10) mol, produced graded dye leakage. A low dose of substance P (5 X 10(-11) mol) potentiated responses to 5-hydroxytryptamine (2.5 X 10(-10) mol), bradykinin (5 X 10(-10) mol), prostaglandin E1 (5 X 10(-10) mol) and adenosine 5'-triphosphate (2.5 X 10(-7) mol) but no histamine (2 X 10(-8) mol). A higher dose of substance P (5 X 10(-10) mol) was potentiated by prostaglandin E1 (5 X 10(-11) mol) and adenosine 5'triphosphate (5 X 10(-9) mol) but but not by histamine (5 X 10(-10) mol) or bradykinin (5 X 10(-11 mol) and was inhibited by 5-hydroxytryptamine (5 X 10(-12) mol). If substance P is released from sensory nerves in some inflammatory states these interactions might be of importance in determining the response observed.