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.