Development and comparison of autopilot and guidance algorithms for missiles

Evcimen, Çağdaş
In order to have an interception with a target, a missile should be guided with a successful guidance algorithm accompanied with a suitable autopilot structure. In this study, different autopilot and guidance designs for a canard-controlled missile are developed. As a first step, nonlinear missile mathematical model is derived by using the equations of motion with aerodynamic coefficients found by Missile DATCOM program. Autopilot design starts by the linearization of the nonlinear missile model around equilibrium flight conditions. Controllers based on the concepts of optimal control theory results and sliding mode control are designed. In all of the designs, angle of attack command and roll angle command type autopilot structures are used. During the design process, variations in angle of attack, Mach number and altitude can lead to significant performance degradation. This problem is typically solved by applying gain-scheduling methodology according to these parameters. There are different types of guidance methods in the literature. Throughout this study, proportional navigation guidance and its modified forms are selected as a base algorithm in the guidance system design. Other robust forms of guidance methods, such as an optimal guidance approach and sliding mode guidance, are also formed for performance comparison with traditional proportional navigation guidance approach. Finally, a new guidance method, optimal proportional-integral guidance, whose performance is the best among all of the methods included in the thesis against highly maneuvering targets, is introduced.


Modeling, stability analysis and control system design of a small-sized tiltrotor uav
Çakıcı, Ferit; Leblebicioğlu, Mehmet Kemal; Department of Electrical and Electronics Engineering (2009)
Unmanned Aerial Vehicles (UAVs) are remotely piloted or self-piloted aircrafts that can carry cameras, sensors, communications equipment or other payloads. Tiltrotor UAVs provide a unique platform that fulfills the needs for ever-changing mission requirements by combining the desired features; hovering like a helicopter and reaching high forward speeds like an airplane. In this work, the conceptual design and aerodynamical model of a realizable small-sized Tiltrotor UAV is constructed, the linearized state-...
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Özgün, Salim; Kuzuoğlu, Mustafa; Department of Electrical and Electronics Engineering (2009)
In this study, a MATLAB® code based on the Shooting and Bouncing Ray (SBR) algorithm is developed to compute the Radar Cross Section (RCS) of complex targets. SBR is based on ray tracing and combine Geometric Optics (GO) and Physical Optics (PO) approaches to compute the RCS of arbitrary scatterers. The presented algorithm is examined in two parts; the first part addresses a new aperture selection strategy named as “conformal aperture”, which is proposed and formulated to increase the performance of the cod...
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Mert, Ahmet; Leblebicioğlu, Mehmet Kemal; Department of Electrical and Electronics Engineering (2009)
Gun and gun turret systems are the primary units of the weapon systems of an aircraft. They are required to hit targets accurately during operations. That is why a complete, high precision control of weapon systems is required. This function is provided by accurate modeling of the system and the design of a suitable controller. This study presents the modeling of and controller design for the gun and turret system for an aircraft. For the controller design purpose, first the mathematical model of the system...
X-band 7 bit mmic phase shifter design
Erçil, Erdinç; Demir, Şimşek; Department of Electrical and Electronics Engineering (2006)
Modern phased array radars require large numbers of electronically controlled phase shifters to steer their beams to the desired direction. The amount of beam steering error depends on the phase resolution of the phase shifters as well as the performance of other parts of the antenna system. The size of the phase shifter in such systems is most of the time needed to be small, which necessitates the MMIC implementation. In the context of this thesis, an X band 7 bit MMIC phase shifter of 2.8125 degree phase ...
Nonlinear controller designs for a reaction wheel actuated observatory satellite
Doruk, Reşat Özgür; Kocaoğlan, Erol; Department of Electrical and Electronics Engineering (2008)
In this research, nonlinear attitude controllers are designed for a low earth orbit satellite intended to be used in observatory missions. The attitude is represented by the Modified Rodriguez Parameters (MRP) which is a minimal representation providing a fully invertible kinematics. As a difference from the classical satellite models existent in the literature, the model of this work incorporates the dynamics of the reaction wheel (actuator) including a brushless dc motor which is armature controlled. The ...
Citation Formats
Ç. Evcimen, “Development and comparison of autopilot and guidance algorithms for missiles,” M.S. - Master of Science, Middle East Technical University, 2007.