Aleksander Nawrat

On the Lyapunov exponents of a class of second-order discrete time linear systems with bounded perturbations

In this note we describe the maximal and the minimal values of Lyapunov exponents for second-order discrete time-invariant linear system perturbed by time-varying bounded perturbations. An interpretation of the results in terms of generalized spectral radius is given. An application of obtained formulas to the robust stability problem is demonstrated on a numerical example.

A Prototype of Unmanned Aerial Vehicle for Image Acquisition

We present the prototype of unmanned aerial vehicle (UAV) as a platform for multispectral acquisition. We are connecting the real-world simulation environment and control software to perform flight tests in SIL simulation. The full control system is based on the cascade of PI controllers with Anti-Windup mechanism, which stabilize the aircraft in the virtual reality. Stabilization of angular speed reduces problems connected with video disruptions. In this article we are presenting all implemented autonomous algorithms, which are based on ENU coordinate system (commonly used in aviation). Simulations are performed in Prepar3D® from Lockheed Martin which also allows to perform visual and thermal images processing. The prototype successfully completed all the test flights and is ready for various applications.

The low cost micro inertial measurement unit

Measuring the orientation of the mobile objects is essential for autonomous navigation. In order to construct low cost, miniature aerial vehicles a miniature inertial measurement unit was designed and constructed by the research team from Silesian University of Technology. Presented device can be distinguished by many times smaller volume than the solutions currently available at the market. It is worth mentioning with smaller size comes no degradation of the quality of measurements. Therefore it is possible to the presented sensor for real life applications.

Advanced Technologies for Intelligent Systems of National Border Security

One of the worlds leading problems in the field of national security is protection of borders and borderlands. This book addresses multiple issues on advanced innovative methods of multi-level control of both ground (UGVs) and aerial drones (UAVs). Those objects combined with innovative algorithms become autonomous objects capable of patrolling chosen borderland areas by themselves and automatically inform the operator of the system about potential place of detection of a specific incident. This is achieved by using sophisticated methods of generation of non-collision trajectory for those types of objects and enabling automatic integration of both ground and aerial unmanned vehicles. The topics included in this book also cover presentation of complete information and communication technology (ICT) systems capable of control, observation and detection of various types of incidents and threats. This book is a valuable source of information for constructors and developers of such solutions for uniformed services. Scientists and researchers involved in computer vision, image processing, data fusion, control algorithms or IC can find many valuable suggestions and solutions. Multiple challenges for such systems are also presented.

SETh-Link the Distributed Management System for Unmanned Mobile Vehicles

This paper presents a novel approach to the problem of managing mobile robots. It is presupposing the existence of the virtual space in which the calculations are made and the real space containing registered mobile robots. Developed and implemented system combines the best features of agent systems and mobile robot management systems based on a central server. Required system computations were distributed on a separate pieces of software responsible for controlling, called controllers, and monitoring, called monitors. A central communication system that allows to log the state of the system and authorization of connections was used. The solution has been tested using real mobile robots and preceded by an analysis of existing solutions.

Technical communique: On new estimates for Lyapunov exponents of discrete time varying linear systems

In this paper, we propose certain new bounds for the Lyapunov exponents of discrete time varying linear systems. The bounds are expressed in terms of spectral radii of matrix coefficients and therefore may be used to establish the exponential stability of time varying system on the basis of eigenvalues of individual coefficient. This approach is known in the literature as frozen time method.

Gyro-Stabilized Platform for Multispectral Image Acquisition

This article presents design and implementation of a gyro-stabilized platform for visible light and infrared image acquisition. The process of selection of appropriate vision sensors and their calibration is presented. Additionally there are presented results of conceptual work, design and construction of the working prototype of the device.

Embedded Micro Inertial Navigation System

This paper presents Embedded Inertial Navigation System designed and manufactured by the Department of Automatic Control and Robotics in Silesian University of Technology, Gliwice, Poland. Designed system is currently one of the smallest in the world. Within it there is implemented INS-GPS loosely coupled data fusion algorithm and point-to-point navigation algorithm. Both the algorithms and the constructed hardware were tested using two unmanned ground vehicles varying in size. Acquired results of those successful tests are presented.

Image Recognition Technique for Unmanned Aerial Vehicles

Developing fast and accurate 2D image processing algorithms is an important task for the practical use of cybernetics. This paper presents an algorithm for fast and accurate blob detection and extraction based on the usage of two parameters *** and *** . The algorithm is aimed to work in the color domain to prevent any loss of information but can also be implemented on gray-scale images. Achieved regions of interest can be further processed to achieve high level description. The algorithm is implemented in Java environment in order to adduce results on different video devices and system platforms.

System for Multi-axial Mechanical Stabilization of Digital Camera

The article presents designed and implemented system for multi-axial mechanical stabilization. The quality of stabilization using closed-loop control, open-loop control and open-loop control with prediction was experimentally measured. Acquired results are presented and discussed.