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Basics of Missile Guidance
Published in Rafael T. Yanushevsky, Modern Missile Guidance, 2019
In order to guide and control a missile several functions must be achieved: Launch function monitors the launch events sequence and establishes the initial missile position and velocity after launch.Targeting function establishes the basic geometry between the missile and target and operates in the coordinate system relative to which the missile targeting and guidance must be performed.Missile guidance function generates guidance commands directing a missile toward the target.Flight control function converts guidance commands into vehicle response; this function is performed by autopilots. The control actuator of a missile generally consists of thrusters that control the direction of the propulsion subsystem’s thrust vector and/or mechanical devices that move external surfaces of the missile in order to alter the aerodynamic forces acting on it.
The Fast Jet Environment
Published in David G. Newman, Flying Fast Jets, 2014
The guidance system consists of a seeker, designed to identify the target, and an avionics component that guides the missile to the intended target. There are several different types of missile guidance technology, but chief among these are radar and infra-red (IR) guidance.
A nonlinear disturbance observer-based adaptive integral sliding mode control for missile guidance system
Published in International Journal of General Systems, 2022
Handan Gürsoy-Demir, Mehmet Önder Efe
In this paper, a novel three-dimensional composite guidance law by using the adaptive integral sliding mode control method and the nonlinear disturbance observer technique is presented for missile guidance systems. At the outset, an ISM guidance law is presented for eliminating the reaching phase of the traditional SMC method. Then, the AISM guidance law is designed for the case in which the target accelerations profile's upper bound is unavailable. The results have shown that the reaching phase is eliminated and a robust guidance law is obtained without the need for an upper bound information of the target accelerations. Additionally, it is analytically demonstrated in our study that the LOS angular rates converge to zero in finite time, as expected from a guidance law. The nonlinear disturbance observer technique has been utilized to generate an estimate by considering the target accelerations as disturbances. The estimated accelerations of the target are provided to the system as a compensation term. Thus the chattering phenomenon that is one of the disadvantages of SMC is eliminated by using the proposed composite guidance law. Simulations on the missile guidance system proved the effectiveness and the feasibility of the proposed guidance law compared to its alternatives.
A ultra wideband dual-polarized antenna with high isolation degree for passive radar application
Published in Electromagnetics, 2021
Miao Wang, Xiuwen Tian, Lizhong Song
The UWB dual-polarized antenna is the key component of passive radar systems such as polarization sensitive missile guidance radar and electronic reconnaissance. It is an important task to design a low-cost, high-performance, stable and reliable UWB dual-polarized antenna for passive radar development. In order to improve the polarization isolation of dual polarization antenna, a technical scheme of composite UWB dual-polarized antenna is proposed in this paper The whole antenna is composed of a modified Vivaldi antenna and a folded dipole log periodic antenna, which makes full use of the structural characteristics of the two radiators and realizes the contactless assembling of the two polarization channels. Combined with the structural design of the antenna, the polarization isolation degree of the dual polarization antenna is significantly improved, which can form a better polarization channel and lay a good foundation for subsequent polarization signal processing. Based on the above ideas, a dual polarization antenna working within the frequency range of 3 GHz~8 GHz is designed. The simulation and experimental results verify the effectiveness of the design scheme. The research results can provide technical basis for engineering application.
Adaptive neural finite-time stabilisation for a class of p-normal form nonlinear systems with unknown virtual control coefficients
Published in International Journal of Control, 2021
As we know, the general control design methods mainly consider the steady-state performance of systems. However, there are often higher requirements for the transient performance of systems in practical applications, especially for the systems with short working time. Such as missile guidance systems and robot control systems. In order to promote the transient performance of control systems, finite-time control theory has attracted wide attention (Ding & Li, 2011; Ding, Li, & Li, 2009; Lin & Qian, 2000). Until now, the main design methods of finite-time control have had the adding a power integrator technique (Chang, 2009; Ding et al., 2009; Huang, Lin, & Yang, 2005; Lin & Qian, 2000; Qian & Li, 2005), the homogeneous method (Bhat & Bernstein, 1997; Bhat & Bernstein, 2002; Hong, Huang, & Xu, 2001), the dynamic gain control design approach (Li, 2015; Zhang, Feng, & Sun, 2012) and some other methods (Haimo, 1986; Jorge et al., 2009; Man, O’Day, & Yu, 1999; Moulay & Perruquetti, 2003; Moulay & Perruquetti, 2005).