scholarly journals Nonlinear Optimal Tracking For Missile Gimbaled Seeker Using Finite-Horizon State Dependent Riccati Equation

2014 ◽  
Vol 60 (2) ◽  
pp. 165-171 ◽  
Author(s):  
Ahmed Khamis ◽  
D. Subbaram Naidu ◽  
Ahmed M. Kamel
Keyword(s):  
Riccati Equation ◽  
Finite Horizon ◽  
Change Of Variables ◽  
Dc Motors ◽  
State Dependent ◽  
Highly Nonlinear ◽  
Wide Range ◽  
Nonlinear Tracking ◽  
Lyapunov Differential Equation ◽  
Operating Points

Abstract The majority of homing guided missiles use gimbaled seekers. The equations describing seeker gimbal system are highly nonlinear. Accurate nonlinear control of the motion of the gimbaled seeker through the attached DC motors is required. In this paper, an online technique for finite-horizon nonlinear tracking problems is presented. The idea of the proposed technique is the change of variables that converts the nonlinear differential Riccati equation to a linear Lyapunov differential equation. The proposed technique is effective for wide range of operating points. Simulation results for a realistic gimbaled system with different engagement scenarios are given to illustrate the effectiveness of the proposed technique.

scholarly journals Nonlinear Finite-Horizon Regulation and Tracking for Systems with Incomplete State Information Using Differential State Dependent Riccati Equation

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Ahmed Khamis ◽  
D. Subbaram Naidu ◽  
Ahmed M. Kamel
Keyword(s):  
Riccati Equation ◽  
Stochastic Systems ◽  
Finite Horizon ◽  
Guidance System ◽  
State Dependent ◽  
Wide Range ◽  
Linearized System ◽  
Estimation And Control ◽  
Regulation And Tracking ◽  
And Control

This paper presents an efficient online technique used for finite-horizon, nonlinear, stochastic, regulator, and tracking problems. This can be accomplished by the integration of the differential SDRE filter algorithm and the finite-horizon state dependent Riccati equation (SDRE) technique. Unlike the previous methods which deal with the linearized system, this technique provides finite-horizon estimation and control of the nonlinear stochastic systems. Further, the proposed technique is effective for a wide range of operating points. Simulation results of a missile guidance system are presented to illustrate the effectiveness of the proposed technique.

Observer-based robust control for flexible-joint robot manipulators: A state-dependent Riccati equation-based approach

2020 ◽  
Vol 42 (16) ◽  
pp. 3135-3155
Author(s):  
Neda Nasiri ◽  
Ahmad Fakharian ◽  
Mohammad Bagher Menhaj
Keyword(s):  
Robust Control ◽  
Control Problem ◽  
Riccati Equation ◽  
Power Transmission ◽  
Control Method ◽  
Main Idea ◽  
Robotic Systems ◽  
Flexible Joint ◽  
State Dependent ◽  
Highly Nonlinear

In this paper, the robust control problem is tackled by employing the state-dependent Riccati equation (SDRE) for uncertain systems with unmeasurable states subject to mismatched time-varying disturbances. The proposed observer-based robust (OBR) controller is applied to two highly nonlinear, coupled and large robotic systems: namely a manipulator presenting joint flexibility due to deformation of the power transmission elements between the actuator and the robot known as flexible-joint robot (FJR) and also an FJR incorporating geared permanent magnet DC motor dynamics in its dynamic model called electrical flexible-joint robot (EFJR). A novel state-dependent coefficient (SDC) form is introduced for uncertain EFJRs. Rather than coping with the OBR control problem for such complex uncertain robotic systems, the main idea is to solve an equivalent nonlinear optimal control problem where the uncertainty and disturbance bounds are incorporated in the performance index. The stability proof is presented. Solving the complicated robust control problem for FJRs and EFJRs subject to uncertainty and disturbances via a simple and flexible nonlinear optimal approach and no need of state measurement are the main advantages of the proposed control method. Finally, simulation results are included to verify the efficiency and superiority of the control scheme.

Vibration suppression and attitude control for the formation flight of flexible satellites by optimally tuned on-off state-dependent Riccati equation approach

2020 ◽  
Vol 42 (15) ◽  
pp. 2984-3001
Author(s):  
Hossein Rouzegar ◽  
Alireza Khosravi ◽  
Pouria Sarhadi
Keyword(s):  
Riccati Equation ◽  
Attitude Control ◽  
Vibration Suppression ◽  
Pso Algorithm ◽  
Formation Flight ◽  
Equation Approach ◽  
Coordination Control ◽  
Suggested Approach ◽  
State Dependent ◽  
Highly Nonlinear

In this paper, vibration suppression and attitude control for the formation flight of flexible satellites using optimally tuned on-off SDRE (state-dependent Riccati equation) approach is discussed. A formation consisting of flexible satellites has highly nonlinear dynamics and the corresponding satellites are subject to vibrations as well as uncertainties due to the practical conditions. Vibrations that are mainly caused by flexible modes of the satellites disorganize the coordination and hinder the formation stability as well as decreasing its performance and lifetime. Hence, flexibility should be considered in formation model and the coordination control needs to address such challenges. Owing to capabilities of SDRE approach for nonlinear systems, it is used as the coordination control. Satellites are assumed to be equipped with thrusters as their actuators which requires the control to be applied as on-off pulses. To this end, an algorithm is suggested to efficiently convert SDRE control into on-off pulses. For optimal tuning of the controller, the particle swarm optimization (PSO) algorithm is employed. Stability of the system has also been analyzed via a Lyapunov-based approach utilizing the region of attraction concept. The proposed on-off SDRE approach has shown to effectively suppress the vibrations in the presence of uncertainties leading to the accurate coordination of the whole formation while consuming less energy. Simulation results show the capability, efficiency, robustness and stability of the suggested approach.

SDRE Based Integrated Roll, Yaw and Pitch Controller Design for 122mm Artillery Rocket

2013 ◽  
Vol 415 ◽  
pp. 200-208 ◽  
Author(s):  
Muhammad Kashif Siddiq ◽  
Jian Cheng Fang ◽  
Wen Bo Yu
Keyword(s):  
Riccati Equation ◽  
Controller Design ◽  
Impact Point ◽  
Design Flexibility ◽  
State Dependent ◽  
Wide Range ◽  
Full State ◽  
Real World Applications ◽  
Attitude Controller ◽  
Simulation Results

State-dependent Riccati equation (SDRE) based controller design is an emerging trend in real world applications. This paper describes the design of an integrated roll, yaw and pitch attitude controller for a fin stabilized and canard controlled 122mm artillery rocket using SDRE technique. The rocket configuration considered is with front canards and foldable straight tail fins, and is given initial spin at the time of launch. Tails fins are deployed immediately after launch and offer high roll damping moment thereby reducing the spin rate to zero within six seconds of flight. The canards are then deployed and the roll orientation of rocket is regulated to zero with the canard deflection commands generated by the SDRE based roll autopilot. Once the roll orientation of rocket is brought to zero, the full state integrated roll, yaw and pitch autopilot comes into action. Elements of the state weighing matrix for Riccati equation have been chosen to be state dependent to exploit the design flexibility offered by the Riccati equation technique. Simulation results show significant reduction in impact point dispersion with the attitude controlled trajectory as compared to uncontrolled trajectory. Monte Carlo simulations have been performed to prove the efficacy of the proposed controller design even in the presence of wide range of deviations in rocket parameters.

Trajectory control of aggressive maneuver by agile autonomous helicopter

2018 ◽  
Vol 233 (4) ◽  
pp. 1526-1536 ◽  
Author(s):  
Behdad Geranmehr ◽  
Esmaeel Khanmirza ◽  
Shahab Kazemi
Keyword(s):  
Riccati Equation ◽  
Tracking Control ◽  
Degrees Of Freedom ◽  
Trajectory Control ◽  
Six Degrees Of Freedom ◽  
Dynamic Representation ◽  
State Dependent ◽  
Highly Nonlinear ◽  
Autonomous Helicopter ◽  
Feedforward Compensators

In this paper, a new state-dependent coefficient parameterization of an agile helicopter dynamics is derived to deal effectively with the optimal trajectory control of aggressive maneuver such as the infinity maneuver with agility. The angular velocity of the main rotor and engine throttle as state and input, respectively, are involved in the dynamic model to improve the maneuvering capability of helicopter. Since the presented six degrees-of-freedom helicopter model is highly nonlinear and nonaffine, particularly nonlinear in actuator, the state-dependent Riccati equation is implemented in the presence of saturation bounds for actuators to achieve precision trajectory control and conquer the challenge of aggressive maneuver tracking control. In addition, new helicopter dynamic representation results in the conventional state-dependent Riccati equation to be applied without prevalent simplifications within dynamic and actuators and also certain augmentations on controllers such as trim or feedforward compensators. Indeed, the proposed controller structure is verified by simulations for both regulation and trajectory tracking problem.

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