J. Judicak

Description of an intelligent small turbo-compressor engine with variable exhaust nozzle

How to use an old turbo-compressor (turboshaft) engine and transfer it into a laboratory system used for design and development of progressive control, diagnostic and modeling algorithms transforming it into an intelligent turbo-compressor engine? The intelligent turbo-compressor engine currently designated as iSTC-21v is a small turbojet engine with a single sided radial compressor, bound combustion chamber, single stage un-cooled turbine and variable exhaust nozzle. The engine is equipped with a real-time measurement and intelligent digital control system using two degrees of freedom (fuel supply and exhaust nozzle diameter). The article describes transformation of an old TS-20/21 engine into such engine, which is suitable for laboratory use, research in different areas of cybernetics with perspective applications in different areas of technical practice like unmanned aerial vehicles, ground auxiliary energetic units, generators, etc. The article is aimed to be inspirative also for hobby engine builders, scale modelers and people who work with small turbo-compressor engines.

Expansion of working envelope of a small turbojet engine MPM-20

Development of aircraft engines is aimed on increase of reliability, efficiency and ecology of operation. The presently still used hydro-mechanic control systems are being replaced by electronic ones characterized by high speed, precision of control and ability to optimize all operating regimes of an engine. One of the aims of research in the Laboratory of intelligent control systems of aircraft engines lies in new possibilities of expansion of working envelope of turbojet engines by implementation of variable exhaust geometry and new approaches in its control strategies and construction solutions. Such expansion can be beneficial for small turbojet engines and increase their possibilities of real-world applications. New control methodologies and approaches can be further expanded to normal sized engines. All these problems are described in the presented article.

Digital start-up control of the small turbojet engine MPM-20

The main thesis of this paper considers the possibilities and difficulties of switching from hydromechanical engine control to FADEC (digital) engine control. Regarding different specifications and elements in system, possible errors, advantages and disadvantages, each method has its specific properties of behavior in specific environments and applications. When considering our controlled system, the MPM-20 small turbojet engine, it is a challenge to propose functional control system with backups and with slight possibility of errors during or before operation. In this paper we propose methods of backups for specific elements, prestart diagnostics and on-line diagnostics.

Basic approaches in adaptive control system design for small turbo-compressor engines

Small turbo-compressor engines represent a specific class of such engines with application in small aircraft and as auxiliary energetic units. Energetic efficiency and high safety standards are nowadays key factors in practical applications of small turbo-compressor engines. One approach to achieve these aims is to design and utilize progressive control algorithms. As turbo-compressor engines represent a non-linear systems operating in a broad range of environments and inner conditions, taking the adaptive approach in controller design can be beneficial. The presented article tests and evaluates different basic approaches in adaptive controller design for a small turbo-compressor engine with modeled altitude and speed characteristics.

Introduction to advanced modeling and control of turbo-prop engines

The article deals with basic description of turboprop engines as a special class of turbine engines - advanced approaches in its modeling and control. The article will deal with description of analytical and experimental approaches in modeling of individual parts of the engine with description of their thermo-dynamics and states. Such engines are systems with two degrees of freedom and demand advanced control algorithm in case of control with single control lever. The article will deal with design of such control algorithm with perspective use of advanced control methods. Such approaches will increase efficiency, fuel consumption, safety and control comfort for the pilot.

Advanced approaches in diagnostics of the turbojet engine MPM-20

This paper deals with modeling and diagnostics of complex systems and with a prestart diagnostics expert system design and implementation. In the area of modeling, the authors describe dynamic models of the speed dependence upon the fuel flow supply of a small turbojet engine MPM-20. The first model is done with use of neural networks and the second is a linear model. Both models are then methodologically incorporated into the diagnostic and backup system of the optical sensor measuring the engine speed.

Intelligent redundant systems for small turbo-compressor engines

Increased redundancy of systems has always been one of the key points to increase reliability and safety of operation of aircraft engines. A special class of such engines is represented by small turbo-compressor engines suitable for propulsion of small aircraft or ground and laboratory use. Specifics of such engines demand design of specialized approaches in order to increase redundancy of their sensor/control systems, thus increasing their operational reliability and safety. The paper proposes general architectures for cost effective approaches to increase the redundancy of sensor and control systems by application of virtual sensor channels and intelligent selectors. The virtual channels are represented by neural networks fusing data from other sensors to dynamically compute the backed up parameter. Intelligent selectors form decision making elements that select the correctly operating control channel. The integration of these two elements creates an intelligent highly redundant sensor and control system suitable for small turbo-compressor engines.

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.

Implementation of the majority method for engine speed diagnostics of the turbojet engine MPM-20

The paper deals with modeling and diagnostics of complex systems. In the area of modeling, the authors describe dynamic models of dependence of speed upon fuel flow supply of a small turbojet engine MPM-20. The first model is done with use of neural networks and the second is a linear model. Both models are then methodologically incorporated into the diagnostic and backup system of the optical sensor measuring the speed of the engine.

Setting the operational envelope of a small turbojet engine by means of analytic modeling and simulation

Mathematical modeling represents an efficient method allowing us to examine properties of a researched object [1]. This article will present the design of an analytic model of a jet engine (MPM-20 engine in particular) that will be used to set the operational envelope of the engine for further use in a control system that will be limited by this envelope.