Control Analysis with Modified LQR Method of Anti-Tank Missile with Vectorization of the Rocket Engine Thrust

This article approaches the issue of the optimal control of a hypothetical anti-tank guided missile (ATGM) with an innovative rocket engine thrust vectorization system. This is a highly non-linear dynamic system; therefore, the linearization of such a mathematical model requires numerous simplifications. For this reason, the application of a classic linear-quadratic regulator (LQR) for controlling such a flying object introduces significant errors, and such a model would diverge significantly from the actual object. This research paper proposes a modified linear-quadratic regulator, which analyzes state and control matrices in flight. The state matrix is replaced by a Jacobian determinant. The ATGM autopilot, through the LQR method, determines the signals that control the control surface deflection angles and the thrust vector via calculated Jacobians. This article supplements and develops the topics addressed in the authors’ previous work. Its added value includes the introduction of control in the flight direction channel and the decimation of the integration step, aimed at speeding up the computational processes of the second control loop, which is the LQR based on a linearized model.

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Tuning of a Linear-Quadratic Stabilization System for an Anti-Aircraft Missile

Aerospace ◽

10.3390/aerospace8020048 ◽

2021 ◽

Vol 8 (2) ◽

pp. 48

Author(s):

Witold Bużantowicz

Keyword(s):

Analytical Solutions ◽

Feedback Loop ◽

Linear Quadratic Regulator ◽

Added Value ◽

Tuning Parameter ◽

Stabilization System ◽

Linear Quadratic ◽

Quadratic Stabilization ◽

Novel Method ◽

Selection Of

A description is given of an application of a linear-quadratic regulator (LQR) for stabilizing the characteristics of an anti-aircraft missile, and an analytical method of selecting the weighting elements of the gain matrix in feedback loop is proposed. A novel method of LQR tuning via a single parameter ς was proposed and tested. The article supplements and develops the topics addressed in the author’s previous work. Its added value includes the observation that the solutions obtained are symmetric pairs, and that the tuning parameter ς proposed for the designed linear-quadratic regulator enables the selection of suitable parameters for the airframe stabilizing loop for the majority of the analytical solutions of the considered Riccati equation.

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Flight Control System Design for Propulsion-Controlled Aircraft

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1243/095441005x30289 ◽

2005 ◽

Vol 219 (4) ◽

pp. 329-340 ◽

Cited By ~ 3

Author(s):

Y Ochi

Keyword(s):

Flight Control ◽

Linear Models ◽

Control Method ◽

Linear Quadratic Regulator ◽

State Feedback Control ◽

Longitudinal Motion ◽

Linear Quadratic ◽

Engine Thrust ◽

Model Following Control ◽

Flight Controls

The loss of an aircraft's primary flight controls can lead to a fatal accident. However, if the engine thrust is available, controllability and safety can be retained. This article describes flight control using engine thrust only when an aircraft has lost all primary flight controls. This is a kind of flight control reconfiguration. For safe return, the aircraft must first descend to a landing area, decelerate to a landing speed, and then be capable of precise flight control for approach and landing. For these purposes, two kinds of controllers are required: a controller for descent and deceleration and a controller for approach and landing. The former controller is designed for longitudinal motion using a model-following control method, based on a linear quadratic regulator. The latter is designed by an H∞ state-feedback control method for both longitudinal and lateral-directional motions. Computer simulation is conducted using linear models of the Boeing 747. The results indicate that flight path control, including approach and landing, is possible using thrust only; however, speed control proves more difficult. However, if the horizontal stabilizer is available, the airspeed can be reduced to a safe landing speed.

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Dynamics and control of a flexible rotating clamped-free beam by SDRE strategy

Aircraft Engineering and Aerospace Technology ◽

10.1108/aeat-11-2017-0240 ◽

2019 ◽

Vol 91 (7) ◽

pp. 1018-1026

Author(s):

Vinicius Piro Barragam ◽

Andre Fenili ◽

Ijar Milagre da Fonseca

Keyword(s):

Riccati Equation ◽

Numerical Solutions ◽

Linear Quadratic Regulator ◽

Flexible Beam ◽

Problem Solution ◽

Integration Step ◽

Linear Quadratic ◽

Planar Case ◽

Content Type ◽

Practical Implications

Purpose The purpose of this paper is the dynamic analysis of the coupled rotation and vibration motion of a system containing a central rigid body to which is attached a flexible beam. Design/methodology/approach The methodology includes the Lagrange’s formulation by using the extended Hamilton’s Principle in conjunction with the assumed modes method to describe the system of equations by ordinary differential equations. The first unconstrained mode of vibration was considered as the solution for the transversal displacement. Such mode emerges as the eigenvalue problem solution associated to the dynamics of the system. The control strategy adopted is a nonlinear analogy of the linear quadratic regulator problem as the Riccati equation is solved at every integration step during the numerical solutions. This strategy is known as state-dependent Riccati equation. Findings By means of computational simulations, it was found the relation between controlled motion and inertia ratio. Research limitations/implications This work is limited to planar case and fixed hub. Practical implications Practical implications of this work realize the design of lighter yet dexterous structures. Originality/value The contribution of this paper is the position and vibration control of a flexible beam accounting for nonlinearity effects and the fact that the structure to where it is clamped has a comparable inertia.

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Pitch and Depth Control of Underwater Glider using LQG and LQR via Kalman Filter

International Journal of Vehicle Structures and Systems ◽

10.4273/ijvss.10.2.12 ◽

2018 ◽

Vol 10 (2) ◽

Author(s):

B. Ullah ◽

M. Ovinis ◽

M.B. Baharom ◽

S.S.A Ali ◽

M.Y. Javaid

Keyword(s):

Kalman Filter ◽

Linear Quadratic Regulator ◽

Good Control ◽

External Noise ◽

Control Surface ◽

Underwater Glider ◽

Linear Quadratic ◽

Control Effort ◽

Underwater Gliders ◽

Depth Control

Underwater gliders are adversely affected by ocean currents because of their low speed, which is compounded by an inability to make quick corrective manoeuvres due to limited control surface and weak buoyancy driven propulsion system. In this paper, Linear Quadratic Regulator (LQR) and Linear Quadratic Gaussian (LQG) robust controllers are presented for pitch and depth control of an underwater glider. The LQR and LQG robust control schemes are implemented using MATLAB/Simulink. A Kalman filter was designed to estimate the pitch of the glider. Based on the simulation results, both controllers are compared to show the robustness in the presence of noise. The LQG controller results shows good control effort in presence of external noise and the stability of the controller performance is guaranteed.

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The Variations in Active Panel Location and Number for a Bioinspired Aircraft Gust Alleviation System

Volume 2: Mechanics and Behavior of Active Materials; Integrated System Design and Implementation; Bio-Inspired Materials and Systems; Energy Harvesting ◽

10.1115/smasis2012-7994 ◽

2012 ◽

Author(s):

Christopher J. Blower ◽

Adam M. Wickenheiser

Keyword(s):

Flight Control ◽

Dynamic Models ◽

Linear Quadratic Regulator ◽

Control Surface ◽

Linear Quadratic ◽

Trailing Edge ◽

Gust Alleviation ◽

Wide Range ◽

Trailing Edge Flaps ◽

Global States

This paper presents the development of a biomimetic closed-loop flight controller that integrates gust alleviation and flight control into a single distributed system of feather-like panels over the upper and lower surfaces. This bio-inspired gust alleviation system (GAS) mimics the techniques used by birds to respond to turbulent and gusting airflow. The GAS design replicates the profile of a bird’s wing through the installation of feather-like panels across the upper and lower surfaces of the airfoil, and replacement of the trailing-edge flaps. While flying through gusts, the flight controller uses a linear quadratic regulator to perform continuous adjustments to the local states through active deflection of electromechanical feathers. This system consequently offers a wide range of flap configurations that enable the vehicle to perform gust response maneuvers unachievable by standard aircraft. The GAS is developed using a 2D adaptive panel method that enables analysis of the airfoil’s aerodynamic performance during all flap configurations. The airfoil’s dynamic model is simulated to calculate the disturbances incurred during gusting flows. The flight controller tracks the vehicles velocity, angle of attack and position, and continuously performs adjustment to the orientation of each flap to induce the corrective responses to inbound gusts. The replacement of standard single trailing edge profile with the integration of a dual trailing edge (DTE) configuration offers a reduction of the aircraft’s deviation from the target flight path through the introduction of aero-braking during strong longitudinal gusts. The introduction of 6 additional surface flaps offers new flap configurations capable of minimizing the disturbances in the aircraft’s global states. Non-linear and linear dynamic models of the 8-flap GAS are compared to a traditional single control surface baseline wing and the DTE configuration. The feedback loops synthesized depend on the inertial changes of the global states; however, variations in flap configuration are compared. The integration of an 8-flap GAS provides enhancements to maneuverability and stability in turbulent intensive environments.

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Optimal Compensator for Anti-Ship Missile with Vectorization of Engine Thrust

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.817.279 ◽

2016 ◽

Vol 817 ◽

pp. 279-288

Author(s):

Łukasz Nocoń ◽

Zbigniew Koruba

Keyword(s):

Equations Of State ◽

Dimensional Space ◽

Three Dimensional ◽

Linear Quadratic Regulator ◽

Linear Quadratic ◽

Graphic Form ◽

Engine Thrust ◽

Gas Dynamic ◽

Control Surfaces ◽

Three Dimensional Space

This paper presents a method of controlling an anti-ship missile with the use of the linear-quadratic regulator (LQR). The equations of dynamics of the flight were linearized and written in the form of equations of state. To control the anti-ship missile, a double executive gas-dynamic (moveable nozzle of exhaust gases) and aerodynamic (moveable control surfaces) system is applied. The missile flight is considered in a three dimensional space, whereas the controlling vector is comprised of four components: two components to control the height of the flight and two components to control the direction of the flight. The results are presented in a graphic form.

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