Zoran Gacovski

Classical and fuzzy-system guidance laws in homing missiles systems

In this paper we present developed models of homing guidance missile systems (surface-to-air and air-to-surface) and of the seeker, which is suitable for research, development and testing of different guidance and control laws, obtained from different synthesis techniques. In homing-guidance missile systems the so called proportional navigation is commonly employed, and various improved solutions and optimal guidance laws are also used. All system models for guidance and control of missiles are rather complex and typically non-linear. Guidance laws are often designed and synthesized by using linearized models, which are obtained from general laws for flying objects (missile and aircrafts) under some assumptions. In homing missile technology, the requirement for missiles to neutralize targets in the presence of widely changing range of variables in different shooting regimes is of paramount importance. To ensure a quality guidance process and small guidance error some self-adaptation property is needed, and we applied fuzzy logic to achieve it in parameters of the guidance law. We have investigated classical proportional navigation, augmented proportional navigation, and optimal guidance laws for different shooting conditions. Simulation programs were realized by using Fortran and Fuzzy Tool Box of Matlab as appropriate, and they constitute a PC training simulator platform. The results on fuzzy guidance laws combined with proportional navigation have been found more effective yet sufficiently simple for practical implementation. All simulation experiments have confirmed these findings.

Mobile Non-Holonomic Robots: On Trajectory Generation and Obstacle Avoidance

Abstract The constraints of non-holonomic mobile robots are expressed as a non-integrable equations. For solving of trajectory generation problem, we have developed computer-aided technique by means of a heuristic method which is based on geometric reasoning and provides deterministic trajectories for all pairs of initial and final configurations and positions. In the cases of motion in environment with fixed obstacles, we have extended this algorithm by adding some control intelligence to the robot (AGV/MR), i.e. by applying of fuzzy-logic controller. A number of simulation experiments on several types of PCs using this technique have been done, and run time takes only a few milliseconds. It has become apparent that this approach is quite attractive for use in real-time motion planning and navigation.

Reformulation of organizing supervisory controller via parameterized fuzzy-petri nets

Abstract This work presents a novel development on modelling the organisation control level in complex systems via mapping our previous model, based on fuzzy Petri-nets with respective rule-based decision-making and appropriate knowledge base, onto a model that is based on para-meterised fuzzy Petri-nets. Proposed model makes a further extension of previous forms of organising supervisory controllers employing fuzzy-Petri reasoning algorithms. This fuzzified and parameterised Petri-net reformulation follows the original concept of G.N. Saridis, and makes a fuzzy supllement to his organising and co-ordinating controllers. Thus it carries a novel generic feature of generality for the supervisory functions of organisation and co-ordination.

Parameterized Petri Net Reformulation of the Fuzzy Production System

This work presents an original transformation of an organization level of complex systems and its model based on fuzzified Petri net, with rule-based decision-making and appropriate knowledge base. This modeling is an extension of all previous forms of fuzzy-Petri reasoning algorithm, because fuzzified parameterized Petri-nets proposed here, can be used to generate a high level abstract plan, even in the absence of complete information, which may be mapped into a specific plan at a lower level of the hierarchy. Our parameterized fuzzy-Petri net reformulation is following the original conception of G. N. Saridis and is fuzzy-addition to his Petri net co-ordinative controller. So it has general generic feature.

Intelligent missile gudance system developed for training at Macedonian military academy

Abstract We have developed a simulation model of homing-guided anti-aircraft or surface-to air (SA) missiles – SAM, suitable for research, development and testing of different guidance and control laws, obtained from synthesis process. This system was developed for the teaching and training purposes of several subjects at Macedonian Military Academy. The topics in External ballistics give cadets knowledge in guided missiles movement, which are considered as dynamic systems and controlled objects. In homing-guidance systems for SA missiles – proportional navigation is most commonly used, and also improved solutions and optimal guidance laws based on modern control theory. All systems for guidance and control of SA missiles are complex and typically non-linear. In order to provide quality process and small guidance error – we have applied fuzzy logic to obtain some parameters for the guidance law. In this paper we present results from investigation of different guidance laws for hypothetic SA missile. The results from fuzzy guidance law combined with proportional navigation are also given. Simulation programs are realized in MATLAB/SIMULINK.

Fuzzy-Petri Net Reasoning System and Transfering of Knowledge to the Markov Chain

This work presents an overview of a reasoning expert system we have developed and implemented in C++. It is based on fuzzified Petri nets, with rule-based decision-making and appropriate knowledge base (KB). The reasoning algorithm is consisting ofcalculating the degrees of fulfillment (DOFs) for all rules of the KB and their assigning to the places of the Petri net. After this, it follows reasoning process with firing of active transitions and calculating of DOFs for output places (propositions of KB) and determining of fuzzy-distribution for output variables, as well as their defuzzified values. As final step, we are transferring these values to the states of a Markov chain in order to perform different command and control tasks. Markov chains are efficient tool for simulation and modeling of stochastic discrete event processes, especially those in military operations, like command and control activities.

On Modelling, Control and Management of a Refugee Exodus Using Theory of Mass-Servicing Systems

Abstract In the spring 1999, due to the Kosovo crisis in its closest neighbourhood, Republic of Macedonia was exposed to a large surge of refugees. Around 400,000 refugees have crossed the border in a period of 30 days. This situation has overloaded the state resources in many fields, and especially in food, water and power supply, transport. communications, environment preservation and medical treatment. In this paper we give short presentation of all efforts that were made by our Government, and we explain the way of modelling and analysis of those processes via massive servicing systems (queuing theory) as well as network planning. This analysis can be useful everywhere when the similar overloads appear in such a short period and territory.

On Resolving Conflicts According to the Documents of the United Nations

Abstract After the Second World War, and especially after the Cold War, the conflicts are getting new scope and shape. The largest parts of them appeared as internal conflicts between two different groups (religious, ethnic etc.). These conflicts deserve and ask for special treatment, and innovated way ofappropriate resolving. Therefore, traditional way of conflict resolving solely it is not sufficient any more. In this paper we will present the way of conflict resolving according to the documents of the United Nations. Especially, the attention is focused on: peace making, peace keeping and peace building