Róbert Bréda

Application of linearized Kalman filter in integration of navigation systems

This contribution presents an analysis and application of Kalman filtering in the field of autonomous and satellite navigation integration for a flying object. This paper deals with properties of the linearized Kalman filter, applied error models and test functionality of the proposed algorithm. An issue of the used and analyzed error models is related with analysis of the sensor properties. Errors for particular inertial measurement units are selected and their implementation to error model of Kalman filter is evaluated. Error characteristics is followed by the analyzed error models for navigation system integration. The article presents a partial solution of dissertation thesis “Integration architectures of navigation systems”, where analysis of Kalman filter leads to proposal of the integrated navigation system for UAV (Unmanned Aerial Vehicle).

Integration architecture design for implementation of a vector magnetometer on board of unmanned vehicle

Content of this contribution is proposal of Inertial Measurement Unit (IMU) for unmanned aerial vehicle. Verification of the real proposal is based on the creation of the integration algorithm utilizing magnetometer data, which outputs are values of speed, distance and attitude angles. Sensor units for proposed measurement unit are chosen considering the criteria, which are described. For this proposal and measurement is used accelerometer ADXL335, gyroscope L3G462A and magnetometer HMC5983. The contribution consist the overview of the chosen mathematical approaches and summary of the results in graphical form. The verification of proposed algorithm is in range of this contribution made on the proposed IMU unit on board of the unmanned aerial vehicle (UAV).

Optimising the aircraft lateral stabilization system in landing mode

Controlling position of an aircraft in its trajectory is a matter of high precision. The requirement on precision is becoming a priority primarily in the phase of landing, when the aircraft is in automated mode of landing controlling/maintaining lateral deviation along the trajectory by autopilot. The contribution is describing shaping and modeling control signals in the stage of final approach for landing. It proposes a system that can eliminate the interfering high-frequency defects of lateral control system stabilizing aircraft deviation during the landing maneuver and simulating the effects of filters onto the feedback dynamics.

Intelligent Situational Control of Small Turbojet Engines

Improvements in reliability, safety, and operational efficiency of aeroengines can be brought in a cost-effective way using advanced control concepts, thus requiring only software updates of their digital control systems. The article presents a comprehensive approach in modular control system design suitable for small gas turbine engines. The control system is based on the methodology of situational control; this means control of the engine under all operational situations including atypical ones, also integrating a diagnostic system, which is usually a separate module. The resulting concept has been evaluated in real-world laboratory conditions using a unique design of small turbojet engine iSTC-21v as well as a state-of-the-art small turbojet engine TJ-100. Our results show that such advanced control system can bring operational quality of an engine with old turbocompressor core iSTC-21v on par with state-of-the-art engines.

Integration architectures of navigation systems for unmanned vehicles

This contribution is part of analysis and research in field of unmanned vehicles navigation developed at Faculty of Aeronautics, Technical University in Kosice. The content of this contribution is an issue of the INS and GNSS integration. Loosely coupled integration architecture was in this case chosen as the basic for simple explanation of the integration issue. Within this contribution the emphasis is focused on suitable Kalman filtering and mathematical background. In the last part of the contribution is given short review on actualization of the basic discrete equations of inertial navigation.

Analysis of GPS satellites position determination using MATLAB ® environment

Content of this contribution is a MATLAB solution of GPS satellite position evaluation based on generated navigation messages of the satellites. Article is focused on issues of the navigation message information content, ephemeris and data processing for evaluation of the Cartesian and spherical satellite constellation. Except analysis of mathematical solutions, the focus is on the position visualization using MATLAB environment. The issue of satellite position and estimation of the ground object position is closely linked with research of navigation architectures for autonomous and satellite navigation systems on Department of Avionics, Faculty of Aeronautics in Kosice. Given MATLAB solution, which is described in this article, is used for education and also as the basic simulation tool for more complex research of Unmanned Aerial Vehicles (UAV) navigation.

Diagnostics of complex systems using thermography

Aim of this paper is to discuss possible method, applicable to diagnostics of complex thermodynamic systems, in our case, the small turbojet engine. Our motivation is based on the fact that, the development of utility properties of aviation technologies, its improvement i.e. accessibility to users cannot be done without detailed observation and tests. In aircraft engine design, 40% of the problems are solved by testing. Therefore the financial cost of the product testing significantly affects the economy of the design development, e.g. production of an aircraft engine. The economy problem of a product placement on the market deepens, if the time and energy consumption is considered. For this reason, reducing the price and time, which significantly affects the output application effect, is a task solvable only by rationalization and organization of testing procedures. When accepting these conditions, one of the possible methods of control of a small turbo jet engine is the utilization of thermography. In order to utilize the thermography to diagnose the engine, multiple processing steps are necessary. These steps include thermal image inference correction, image preprocessing, segmentation and correlation analysis. We discuss these steps further in the paper, with main aim on the image inference correction.