Carl E. Wick

Design of a prototype miniature autonomous underwater vehicle

Platoons of cooperating autonomous underwater vehicles have the potential to contribute significantly to scientific investigations in the marine environment. Platoons of vehicles can survey large areas, adaptively track and measure time-varying processes such as tidal fronts and algal blooms, and they are robust to single-point failures. We have developed a prototype miniature low-cost autonomous underwater vehicle to address the platform requirements of these missions. The vehicle is designed as a test-bed for the development of distributed control and estimation algorithms, and for experiments in advanced navigation and control.

A miniature low-cost autonomous underwater vehicle

We announce the development of a prototype miniature low-cost autonomous underwater vehicle (AUV). The vehicle was designed to explore technology for one-way military applications, including minefield mapping/tagging, and cooperative underwater activities with similar units, but could also find application in shallow water mapping and remote sensing. The prototype vehicle measures approximately 24 inches long (61 m) by 3.5 inches in diameter (8.9 cm), displacing approximately 7 lbs (3.3 kg). We present the physical design of this vehicle, our findings from initial testing, including the performance of inexpensive sensors used for vehicle navigation.

Small inertial sensors for a miniature autonomous underwater vehicle

Testing and algorithm development are addressed for the guidance system of a low-cost (disposable) miniature autonomous underwater vehicle. The requirements for low-cost and small size systems typically necessitate the use of low-performance sensors. In this work, we address the limitations of low-performance inertial sensors. Mechanized calibration routines are developed to compensate for high drift rates in gyro calibration coefficients, and compass/gyro stabilization methods are investigated to address susceptibility of the compass to magnetic interference.

Hard disk interface used in computer forensic science

This paper will discuss a project that is related to the NIST development of standard methods for testing disk imaging tools. The goal of the project is to enhance current software-intensive tool tests by providing a hardware-oriented mechanism for simulating disk drive faults. This new system is significant because knowing the behavior of computer forensics tools operating in the presence of I/O errors is critical to a complete evaluation of disk imaging tools, and it is difficult to simulate hardware errors accurately with software alone.

Systems Ball - a creative capstone design experience

This paper describes a design competition called Systems Ball that has been successfully used in the Systems Engineering design course sequence at the United States Naval Academy. In the Systems Ball competition, student teams build remotely operated vehicles that partake in a combative version of basketball. Systems Ball has been found to be an effective and fun way to guide multiple student teams through the design process while stimulating their creativity.

Modeling of illumination effects for image processing of microvessels

This research is in support of the development of an image processing system which is capable of detecting and tracking blood vessels in photographs or video images of the human microcirculation system. We describe a model which replicates the illumination processes contributing to a film or video image of the microvessels of the human bulbar conjunctiva. The model provides a foundation for microvessel detection algorithms, for measurement of vessel parameters, for determining relative depth of blood vessels, and for separating neighboring vessels in complex images. The model is based on a cylindrical vessel embedded in a diffuse medium which is on a reflecting background. A light source illuminating the scene is reflected by its components and passes through a pinhole to an image plane, which records these reflections as intensity values at discrete pixel locations. Fundamental physical principles which include Lamberts cosine law, isotropic spreading, Fresnels law and Beers law are systematically applied to the model. A video apparatus and a phantom were constructed to analyze different illumination conditions and to verify the model. A simulation based on the model compared favorably with data taken from phantom images.

Teaching DSP servo-motor control with extended SHARC evaluation boards; the Pilot-Fish project

In this paper, the authors discuss a locally-generated daughter-board extension to the popular SHARC DSP evaluation module (EVM). The board improves the performance of this inexpensive hardware in many applications that involve feedback control. They discuss the use of this hardware in a simple servomotor control experiment that demonstrates many of the fundamentals of digital signal processor control of physical plants.

Depth from physics: develpoment of a robust classifier for 2D image analysis

Blood vessels overlying one another at distinct depths (and hence appearing to intersect) in the sclera of the eye can be distinguished reliably from those that in fact do branch within the same depth, using only the information contained in a single photograph of the conjunctiva. That conclusion arises from extension of earlier work that qualitatively inferred relative depth of vessels. The current research was motivated by the need to quantify such inferences in terms of their sensitivities and robustness. A physics first principles model forms the basis for selection of features that capture blood vessel depth information. Features extracted from the image are shown to be useful in that effort; their utility is verified with phantoms that mimic the behavior of the conjunctiva and sclera. Because no special preparations are needed, the method works as well on archived images as on newly-acquired ones, and thus can be used in retrospective studies of images of the eye and other diffuse media.

Using modeling and fuzzy logic to detect and track microvessels in conjunctiva images

The conjunctiva is a thin membrane that covers the surface of the eye and reveals the small blood vessels of the microcirculation for detailed non-invasive study. The morphology of these vessels is of interest because structural changes in the vascular bed have been shown to occur coincident with certain diseases. Detecting these changes could be used as an early indication, leading to more timely treatment. Our efforts have been to find a reliable method to automate the currently manual methods of analyzing images of the conjunctiva. Our approach has been to first model the illumination/reflection processes that contribute to a scene. We have then used the products of this model to develop some algorithms based on fuzzy logic to reliably detect blood vessel pixels in actual conjunctiva images. Work is progressing in the use of fuzzy logic concepts to track vessels from these detected points so as to provide complete vessel paths and other morphological information.<<ETX>>

Communications track for systems engineering majors

The Weapons and Systems Engineering Department at the United States Naval Academy offers an undergraduate degree in Systems Engineering (Controls) to approximately 100 midshipmen annually. Fourth year students are allowed to specialize by taking a two-course track chosen from several areas of interest. Our communications track is one of these areas. The communication track integrates signal analysis and processing methods, and modern communication systems operation principles through hands-on laboratory experience and computer simulation. The uniqueness of this track is that it is offered to students that do not have traditional electrical engineering background. The paper details our experience in teaching modern communication systems to undergraduate systems engineering majors.