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The state of present technologies in technical and also non-technical practice is represented by growing complexity of systems. A turbojet engine as a complex system is multidimensional highly parametric system with complex dynamics and strong non-linear behavior with stochastic properties. Its particular property is operation in a wide spectrum of changes of its operating environment (e.g., temperatures from -60 to +40 °C, different humidity, different pressures, etc.). If we want to secure optimal function of such system, it is necessary to develop models and control systems implementing the newest knowledge from the areas of automation, control technologies preferably with elements of artificial intelligence (AI). The present control systems and dynamic models are often limited to control or modeling of a complex system in its certain (operational) states. However, in practice the turbojet engine finds itself in very different operating conditions that influence its parameters of operation and characteristics. To create progressive control algorithms for a turbojet engine, it is necessary to design models in the whole dynamic spectrum of the modeled system including its erroneous states. Furthermore we need to design a control system that will secure operation converging towards optimality in all eventual states of working environment and also inner states of the system represented by its parameters. This leads to the need of having increased intelligence of control of turbojet engines that reduces workload of a pilot and also increases safety of operation. Safety represents a decisive factor in design of control systems of turbojet engines and is presently bound with increasing authority of them. The present trend designates such control systems as FADEC – Full Authority Digital Engine Control, however in reality such control systems have different levels of authority, intelligence and come in very different implementations. These are often not presented as they are intellectual properties of commercial companies. The article will be aimed on description of some present trends in development of FADEC systems and own proposals of methodologies leading towards design and implementation of a FADEC system with high level of intelligence able to solve all operational situations of a turbojet engine. This is strictly bound with presentation of modern methods of modeling of turbojet engines and the use of advanced methods of mainly sub-symbolic artificial intelligence. The proposed methods are all tested in real-world environment using a small turbojet engine MPM-20 in our laboratory setup. Therefore the article will also deal with approaches in digital real-time measurement of state parameters of this engine and design of control algorithms from engineering standpoint.

Adaptive control is one of the possible methodologies aimed to increase the efficiency of controlled operation of complex systems. Highly theoretical approaches are often presented in design of adaptive control algorithms. The article is aimed at practical aspects of adaptive controller design for a class of small turbojet engines. Such engines can be modeled as non-linear complex systems operating in a broad range of environmental parameters as presented in the article. The designed triple loop control architecture shows increased precision of control keeping acceleration schedule of the simulated engine and is not susceptible to outer disturbances. This approach can also be used for other classes of turbojet engines as well other similar technical systems

Modern turbojet engines mainly use computerized digital engine control systems. This opens the way for application of advanced algorithms aimed at increasing their operational efficiency and safety. The theory of robust control is a set of methods known for good results in complex control tasks, making them ideal candidates for application in the current turbojet engine control units. Different methodologies in the design of robust controllers, utilizing a small turbojet engine with variable exhaust nozzle designated as iSTC-21v, were therefore investigated in the article. The resulting controllers were evaluated for efficiency in laboratory conditions. The aim was to find a suitable approach and design method for robust controllers, taking into account the limitations and specifics of a real turbojet engine and its hardware, contrary to most studies which have used only simulated environments. The article shows the most effective approach in the design of robust controllers and the resulting speed controllers for a class of small turbojet engines, which can be applied in a discrete digital control environment.

In order to efficiently control passenger aircraft in general., the control process is usually adapted according to flight situations. A system for selection of a particular flight situation contains complex decision making algorithm using a lot of sensors. The aim of the paper is to present a very simple., yet efficient approach of a basic flight phase classification., which is applicable in small unmanned airplanes., which have a limited computational and sensor capabilities. The flight phase selection system can be then implemented in an intelligent control and flight envelope protection system of such UAV., which are also presented in the paper.

Experimental identification as one of the possibilities of creating mathematical models of complex systems is a fast, simple and easy-to-use methodology. Even with a low percentage of knowledge of the modelled object (functionality, internal bonds, etc.) it is possible to obtain a mathematical model with high quality - similarity - verification. The disadvantage of experimental identification is the necessary existence of a functional complex system and a measuring - sensing apparatus. The Laboratory of intelligent control systems of aircraft engines has four full-featured functional systems - small and micro turbo compressor aviation jet engines. Experimental identification of small jet engines based on the measured transition characteristic is being researched using these engines. The question and topic of this article is to verify the possibilities and ways of creating mathematical models by experimental identification based on the acquired - measured transition characteristics for the smallest category of aircraft engines - micro turbo-compressor jet engine and evaluate obtained simulation models of different complexity.

The article presents a method for implementation of "anytime" algorithms into digital real-time control system for a small turbojet engine iSTC-21v. This method presents an approach that will be used for future work in design of the control system. The presented method is an extension of the actual developed control system of engine, which uses the theory of situational control of complex systems. This control system uses progressive control algorithms. For practical implementation of this control system it is important to think about computational complexity. Control systems of aircraft engines use computer (Full Authority Electronic engine control — FADEC) with limited computation resources. Aircraft engines work in environment with stochastic conditions. It is necessary to ensure reliable and stable operation of engine. Anytime algorithms can help to solve this problem and to meet the safety requirements.

The goal of this article is to develop a linear mathematical model for a small scale turbojet engine with variable convergent nozzle, and validate it on existing laboratory hardware owned by the authors’ Departments.Control of gas turbine engines plays an essential role in the safety of aviation. Although its role is constantly expanding, ranging from pilot workload reduction to detailed diagnostics, the basic competence is to regulate the thrust output of the power plant with maximum available accuracy, rapidity, stability, and robustness. The linear quadratic control is one possible solution for the above mentioned criteria.Although civil aircraft engines include fixed exhaust nozzle geometry, in military applications the exhaust nozzle geometry is also adjustable to reach optimum efficiency due to better matching of individual engine components, etc.In the present article the authors deduce the members of state space governing equations to acquire the basis of the LQ control.The established model is based on the physical laws describing the operational behavior of the engine as well as its complexity should be reduced to an acceptable level where still enough details remain to reflect the nature of the controlled object.

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).

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.

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.

The paper deals with design of an intelligent supervisory system usable in the area of engineering applications of small turbojet engines. Such supervisory system consists of diagnostic and control system applied in different phases of the engine’s operation. In order to design it we need to know the object and its models that will be realized by means of situational modeling concept and neural networks. Diagnostic system will be based on these types of models applied into the majority voting method of online diagnostic. Intelligent supervisory system will also include off-line pre-start diagnostics for such engine with perspective health monitor database.

This paper presents a general description of behavior of a complex thermodynamic system, represented by a small turbojet engine MPM 20. The main aim is to provide basic constraints of chosen measured parameters. Obtained results will be used in future data filtering, to recognize faulty output sensor values, critical situations and normal engine operation field. According to these constraints the engines' operational envelope can also be defined by means of measured parameters. Also using constraints, we may divide the engine operation into several operational modes. These modes are dependent on the absolute value of a measured parameter, a coefficient of two parameters, or a coefficient calculated by more than two parameters.

Summary form only given. The Laboratory of Intelligent Control Systems of Aircraft Engines has been built around the idea of design implementation and testing of progressive algorithms in the areas of identification, modeling, control and diagnostics of complex systems. As such complex system a class of small turbojet engines suitable for laboratory experiments and utilization has been used, the engine MPM-20 derived from turbo-starter TS-20 in particular. Such small turbojet engines exhibit similar dynamic behavior as normal sized engines and have many properties of complex systems like non-linear characteristics, variable cross bindings, broad operational range, non stationary parameters and elements of stochastic behavior.

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.

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.

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.

The paper deals with approaches in modeling of a complex electro-hydro-mechanical system. The proposed system is a fuel metering device that is a non-linear system with hysteresis and transport delays. The classical methods of modeling demand knowledge of mechanics and inner structure of the researched object. The paper deals mainly with experimental data driven methods of modeling. The created models will serve as a basis for controller design to employ the fuel metering device into the digital control system of a small 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.

Mathematical modeling represents an efficient method allowing us to examine properties of a researched object [1]. Realization of mathematic models has become a fundamental part of design of many complex systems. By use of simulation, we can experiment with mathematical model similarly as with the real object without the risk of damage and with much lower expenses. Modeling represents experimental process that asserts the examined original (the modeled system) unambiguously another physical or abstract system. The article deals with approach to virtual particular analytic modeling of a compressor and explores some advanced hybrid concepts in modeling of such engine using methods of artificial intelligence.

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.

Mathematical modeling represents an efficient method allowing us to examine properties of a researched object [1]. Realization of mathematic models has become a fundamental part of design of many complex systems. By use of simulation, we can experiment with mathematical model similarly as with the real object without the risk of critical states and with much lower expenses. Modeling represents experimental process that asserts to the examined original, the real object (or the modeled system) unambiguously another physical or abstract system. The article deals with approach to virtual modeling of a compressor in a small turbojet engine. This article will present design of analytic model of a jet engine (MPM-20 engine in particular) and its graphical depiction into its compressor characteristics.

The article deals with modern concepts of control systems used in turbojet engines. We specifically aim on description of control systems using methods and concepts of artificial intelligence, which can bring a new quality in terms of operation and safety of turbojet engines' operation. We also propose a design of intelligent control system for small turbojet engine MPM-20 within the scope of methodology of situational control together with exploration of macro and micro situations concepts.

The growing demands on safety authority and intelligence of control systems requires new approaches in design. One approach that is usable and potentially effective are anytime control algorithms that can be used in the area of modeling and control [6, 11, 14, 15]. Use of such algorithms allows the system to flexibly react on changes of outer environment and be able to survive deficiency of time, information and resources.

Mathematical modeling represents and efficient method allowing us to examine properties of a researched object [1]. Realization of mathematic models has become fundamental part of design of many complex systems. By use of simulation, we can experiment with mathematical model similarly as with the real object without the risk of critical states and with much lower expenses. Modeling represents experimental process that asserts to the examined original, the real object (or the modeled system) unambiguously another physical or abstract system. The article deals with approach to virtual modeling of a compressor in a small turbojet engine.

The article deals with full authority digital engine control (FADEC) systems and possibilities of application of concepts and methods of artificial intelligence in such control system. FADEC represents a framework where the most modern methods of artificial intelligence can be applied. This represents a great potential for increase of reliability, efficiency and overall quality of control of turbojet engines. We are trying to design and implement a FADEC control system for our small experimental turbojet engine MPM 20.

The article deals with basics of modeling of our small experimental turbojet engine MPM 20 and the following design of a complex situational control system with elements of anytime control algorithms bound with a developed analytical model of the engine. By use of advanced algorithms using methods of artificial intelligence in a robust framework to achieve the aims of reliability and high efficiency, we are trying demonstrate their usability and proficiency in the area of turbojet engines. All the tests and data come from measurements on a real object of our experimental small turbojet engine and are therefore a good step to be used on normal sized engines.

Small turbojet engines represent a special class of turbine driven engines. They are suitable for scientific purposes and research of certain thermodynamic processes ongoing in turbojet engines. Moreover such engines can be used for research in the area of alternative fuels and new methods of digital control and measurement. Our research, which is also presented in this article, is headed toward these aims. We evaluate and propose a system of digital measurement of a particular small turbojet engine - MPM 20. Such engine can be considered as highly non-linear large scale system. According to obtained data and experiments we propose different models of the engine and design of situational control algorithms for the engine with use of certain methods of artificial intelligence as new methods of control and modeling of large scale systems.

Small turbojet engines represent a special class of turbine driven engines. They are suitable for scientific purposes and research of certain thermodynamic processes ongoing in turbojet engines. Moreover such engines can be used for research in the area of alternative fuels and new methods of digital control and measurement. Our research, which is also presented in this article, is headed toward these aims. We evaluate and propose a system of digital measurement of a particular small turbojet engine - MPM 20. Such engine can be considered as highly non-linear large scale system. According to obtained data and experiments we propose different model models of the engine and design of situational control algorithms for the engine with use of certain methods of artificial intelligence as new methods of control and modeling of large scale systems.

Small turbojet engines represent a special class of turbine driven engines. They are suitable for scientific purposes and research of certain thermodynamic processes ongoing in turbojet engines. Moreover such engines can be used for research in the area of alternative fuels and new methods of digital control and measurement. Our research, which is also presented in this article, is headed toward these aims. We evaluate and propose a system of digital measurement of a particular small turbojet engine - MPM 20. Such engine can be considered as highly non-linear large scale system. According to obtained data and experiments we propose different approaches to modeling of the engine with use of analytic experimental and certain methods of artificial intelligence as new methods of modeling of large scale systems.

Small turbojet engines represent a special class of turbine driven engines. They are suitable for scientific purposes and research of certain thermodynamic processes ongoing in turbojet engines. Moreover such engines can be used for research in the area of alternative fuels and new methods of digital control and measurement. Our research, which is also presented in this article, is headed toward these aims. We evaluate and propose a system of digital measurement of a particular small turbojet engine -MPM 20. Such engine can be considered as highly non-linear large scale system. According to obtained data and experiments we propose different model models of the engine and design of situational control algorithms for the engine with use of certain methods of artificial intelligence as new methods of control and modeling of large scale systems.

Aircrafts' turbo-compressor engines may be considered as very complex systems with many mutual and also positive feedbacks. Another characteristic of such systems is that they operate in a very large range of outer environment parameters which causes very different behaviour within their working conditions. Critical susceptibility to erroneous states where requirements for reliability are set to highest degree, it is necessary to secure control of such engines in their every state and secure their operation under every environmental or engine conditions. Situational control methods offer such tools to secure not just stabilization of an engine, but its control, using different control strategies for different working conditions.

Small turbojet engines represent a special class of turbine driven engines. They are suitable for scientific purposes and research of certain thermodynamic processes ongoing in turbojet engines. Moreover such engines can be used for research in the area of alternative fuels and new methods of digital control and measurement. Our research, which is also presented in this article, is headed toward these aims. We evaluate and propose a system of digital measurement of a particular small turbojet engine - MPM 20. Such engine can be considered as highly non-linear large scale system. According to obtained data and experiments we propose situational model and situational control algorithms for the engine with use of certain methods of artificial intelligence as new methods of control of large scale systems.