Immersion- and invariance-based adaptive missile control using filtered signals

2012 ◽  
Vol 226 (6) ◽  
pp. 646-663 ◽  
Author(s):  
K W Lee ◽  
S N Singh
Keyword(s):  
Control System ◽  
Closed Loop ◽  
Angle Of Attack ◽  
Loop System ◽  
Certainty Equivalent ◽  
Analytical Relation ◽  
Parametric Uncertainties ◽  
State Variables ◽  
Closed Loop System ◽  
Immersion And Invariance

The article presents a new non-certainty-equivalent adaptive (NCEA) longitudinal autopilot for the control of a missile based on the immersion and invariance theory. The interest here is to control the angle of attack of the missile in the presence of large parametric uncertainties. For the derivation of the control law, a backstepping design procedure is used. At each step of the design, certain filtered signals are generated for the synthesis of a stabilizing control signal and a parameter estimator. Using Lyapunov stability analysis, it is shown that in the closed-loop system, trajectory control of the angle of attack is accomplished, and the trajectories of the system are attracted to certain manifold in the space of state variables and parameter errors. For stability in the closed-loop system, an explicit analytical relation involving the controller gains is obtained. It may be pointed out that recently an adaptive autopilot based on the immersion and inversion theory has been designed, but it has stringent requirements because for its synthesis, the derivatives of the Mach number and angle of attack must be known, and a large number of parameters must be updated. The derived control system of this article is synthesized using only the state variables, and its identifier is of lower order. A traditional certainty-equivalent adaptive autopilot is also presented for comparison. Simulation results are obtained which show that the designed NCEA control system can accomplish angle of attack control despite large parametric uncertainties; and it can give better tracking performance than the traditional controller.

Control System Synthesis Based on Plant Test Data

1995 ◽  
Vol 117 (4) ◽  
pp. 484-489
Author(s):  
Jenq-Tzong H. Chan
Keyword(s):  
Control System ◽  
Test Data ◽  
Closed Loop ◽  
Explicit Knowledge ◽  
Linear Time ◽  
Open Loop ◽  
Loop System ◽  
Closed Loop System ◽  
System Synthesis ◽  
Control System Synthesis

A correlation equation is established between open-loop test data and the desired closed-loop system characteristics permitting control system synthesis to be done on the basis of a numerical approach using experimental data. The method is applicable when the system is linear-time-invariant and open-loop stable. The major merits of the algorithm are two-fold: 1) Arbitrary placement of the closed-loop system equation is possible, and 2) explicit knowledge of an open-loop system model is not needed for the controller synthesis.

Robust Piecewise-Linear State Observers for Flexible Link Mechanisms

2006 ◽  
Author(s):  
Roberto Caracciolo ◽  
Dario Richiedei ◽  
Alberto Trevisani
Keyword(s):  
Nonlinear Model ◽  
Closed Loop ◽  
Linear Models ◽  
Piecewise Linear ◽  
Equilibrium Points ◽  
Loop System ◽  
State Variables ◽  
Flexible Link ◽  
Closed Loop System ◽  
State Observers

This paper tackles the problem of designing state observers for flexible link mechanisms: an investigation is made on the possibility of employing observers making use of suitable piecewise-linear truncated dynamics models. A general approach is proposed, which provides an objective way of synthesizing observers preventing the instability that may arise from using reduced-order linearized models. The approach leads to the identification of the regions of the domain of the state variables where the linear approximations of the nonlinear model can be considered acceptable. To this purpose, first of all, the stability of the equilibrium points of the closed-loop system is assessed by applying the eigenvalue analysis to appropriate piecewise-linear models. Admittedly, the dynamics of such a closed-loop system is affected by the pole perturbation caused by spillover, and by the discrepancies between the linearized models of the plant and the one of the observer. Additionally, when nodal elastic displacements and velocities are not bounded in the infinitesimal neighborhoods of the equilibrium points, the difference between the nonlinear model and the locally-linearized one is expressed in terms of unstructured uncertainty and stability is assessed by H∞ robust analysis. The method is demonstrated by applying it to a closed-chain flexible link mechanism.

A Robust Design Optimization Framework for Systematic Model-Based Calibration of Engine Control Systems

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Hoseinali Borhan ◽  
Edmund Hodzen
Keyword(s):  
Control System ◽  
Design Optimization ◽  
Robust Design ◽  
Closed Loop ◽  
Optimization Technique ◽  
Loop System ◽  
Robust Design Optimization ◽  
Engine Control ◽  
Closed Loop System ◽  
Model Based

In this paper, a systematic model-based calibration framework basing on robust design optimization technique is developed for engine control system. In this framework, the control system is calibrated in an optimization fashion where both performance and robustness of the closed-loop system to uncertainties are optimized. The proposed calibration process has three steps: in the first step, the optimal performance of the system at the nominal conditions, where the effects of uncertainties are ignored, is computed by formulation of the controller calibration as an optimization problem. The capabilities of the controller are fully explored at nominal conditions. In the second step, the robustness and sensitivity of a selected control design to the system uncertainties are analyzed using Monte Carlo simulation. In the third step, robust design optimization is applied to optimize both performance and robustness of the closed-loop system to the uncertainties. The robustness capabilities of the controller are fully explored and the one that satisfies both performance and robustness requirements is selected. This process is implemented for the calibration of an advanced diesel air path control system with a variable geometry turbocharger (VGT) and dual loop exhaust gas recirculation (EGR) architecture.

scholarly journals Computation of time-delay for Delayed Network Controlled Temperature Control System

2021 ◽  
Vol 2070 (1) ◽  
pp. 012102
Author(s):  
V Venkatachalam ◽  
M Ramasubramanian ◽  
M Thirumarimurugan ◽  
D Prabhakaran
Keyword(s):  
Control System ◽  
Stability Analysis ◽  
Temperature Control ◽  
Closed Loop ◽  
Simulation Software ◽  
Loop System ◽  
Temperature Control System ◽  
Closed Loop System ◽  
The Stability ◽  
Time Invariant

Abstract This paper presents an Investigation on the stability of network controlled temperature control system having Time-Invariant feedback delays, by utilizing a direct method for TDS stability analysis. A PI controller based stability analysis for temperature control system with Time invariant feedback loop delay has been constructed in this paper. The stability problem has been formulated based on the transfer function model of the closed loop system with various time delays. For different subsets of the controller parameters, based on the stability criterion’s maximal permissible bound of the network link delay that the closed loop system can accommodate without losing the stability has been computed. The effectiveness of the obtained result was validated on a benchmark temperature control system using MATLAB simulation software.

scholarly journals Composite Immersion and Invariance Based Adaptive Attitude Control of Asteroid-Orbiting Spacecraft in Elliptic Orbit

2021 ◽  
Author(s):  
Keum W Lee ◽  
Sahjendra N Singh
Keyword(s):  
Attitude Control ◽  
Closed Loop ◽  
Tracking Error ◽  
Loop System ◽  
Closed Loop System ◽  
Immersion And Invariance ◽  
State Dependent ◽  
Dependent Vector ◽  
Yaw Angle ◽  
Angle Tracking

Abstract This paper proposes a new composite noncertainty-equivalence adaptive (CNCEA) control system for the attitude (roll, pitch, and yaw angle) control of a spacecraft in an orbit around a uniformly rotating asteroid based on the immersion and invariance (I&I) theory. For the design, it is assumed that the asteroid's gravitational parameters and the spacecraft's inertia matrix are not known. In contrast to certainty-equivalence adaptive (CEA) or noncertainty-equivalence adaptive (NCEA) systems, the CNCEA attitude control system's composite identifier uses the attitude angle tracking error, a nonlinear state-dependent vector function, and model prediction error for parameter estimation. The Lyapunov analysis shows that in the closed-loop system, the Euler angles asymptotically track the reference attitude trajectories. Interestingly, there exist two parameter error-dependent attractive manifolds, to which the closed-loop system's trajectories converge. Moreover, the composite identifier using two types of error signals provides stronger stability properties in the closed-loop system. Simulation results are presented for the attitude control of a spacecraft orbiting in the vicinity of the asteroid 433 Eros. These results show precise nadir pointing attitude regulation, despite uncertainties in the system.

scholarly journals Efficient and Novel voltage control method using DC-DC Cuk Converter under Load Variation

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
Syed Mujtaba Mahdi Mudassir ◽  
Faheem Ahmed Khan ◽  
Shaziya Sultana
Keyword(s):  
Control System ◽  
Closed Loop ◽  
Sliding Mode ◽  
Loop System ◽  
Control Mode ◽  
System Response ◽  
Switching Function ◽  
Sliding Modes ◽  
Closed Loop System ◽  
Cuk Converter

A control system is a set of mechanical or electronic devices that regulates other devices or systems by way of control loops. Typically, control systems are computerized. The mode of operation in a Control System where controlling variables is a function of the system and the structure is changed knowingly according to set of rules, which are already declared: for example a sensor based  system, is called as sliding control mode where the feedback control system response is limited and revolves around surface in the space to a point of equilibrium. In this mode of schemes, a switching variable dictates which form of control is to be used at a given instant, depending on the position of the state from the surface. First a set of points for which the switching function is null is used called as sliding surface. Sliding Mode Control (SMC) is a very robust technique which can handle sudden and large changes in dynamics of the system which can be applied to many areas like controlling of motor, aircraft and spacecraft, process control and power systems. SMC is one of the best tool in the industry to design controllers for the systems which has variable values, and provides robust properties against matched uncertainties, However,this use of SMC can only be achieved after the occurrence of the sliding mode. Before the occurrence of the switching function as null i.e. during the reaching phase, the system is affected by even matched ones. Several first order SMC applications for linear and nonlinear systems can be found in the literature [1]. Hence to eliminate the reaching phase and to make sure the ruggedness of the system throughout the entire closed-loop system response Integral Sliding Modes are used. In this paper a design procedure for sliding mode controllers for better control of voltage is applied, and then the ideas implemented are extended to all integral sliding modes in order to ensure optimum operation of entire system response[2]. Necessary conditions for the existence of sliding modes are also given. The closed-loop system is also proved to be exponentially stable. Simulation and experimental tests using the prototype of controlled DC-DC  CUK converter were performed to validate the proposed control approach.

scholarly journals MODELING AND SIMULATION OF QUAY CRANE CONTROL SYSTEM FOR PID CONTROLLER OPTIMAL PARAMETERS DETERMINATION / KRANTINĖS KRANO VALDYMO SISTEMOS KOMPIUTERINIS MODELIAVIMAS OPTIMALIOMS PID VALDIKLIO VERTĖMS NUSTATYTI

2016 ◽  
Vol 8 (5) ◽  
pp. 540-547
Author(s):  
Tomas Eglynas ◽  
Audrius Senulis ◽  
Marijonas Bogdevičius ◽  
Arūnas Andziulis ◽  
Mindaugas Jusis
Keyword(s):  
Mathematical Model ◽  
Parameter Estimation ◽  
Control System ◽  
Pid Controller ◽  
Closed Loop ◽  
Loop System ◽  
Control Algorithms ◽  
Closed Loop System ◽  
Matlab Simulink ◽  
Crane Control

The main control object of Quay crane, which is operating in seaport intermodal terminal cargo loading and unloading process, is the crane trolley. One of the main frequent problem, which occurs, is the swinging of the container. This swinging is caused not only by external forces but also by the movement of the trolley. The research results of recent years produced various types of control algorithms by the other researchers. The control algorithms are solving separate control problems of Quay crane in laboratory environment. However, there is still complex control algorithm design and the controller’s parameter estimation problems to be solved. This paper presents mathematical model of the Quay crane trolley mechanism with the suspended cargo. The mathematical model is implemented in Matlab Simulink environment and using Dormand-Prince solving method. The presented model of laboratory quay crane mathematical model is dedicated to parameter estimation of PID controller of closed loop system with the usage of S –form speed input profile. The article includes the dynamic model of the presented system, the description of closed loop system and modeling results. These results will be used as an initial information for the PID parameters estimation in real quay crane control system. The simu-lation of the model was performed using estimated values of controller. The sway influence of the cargo, the usage of the trolley speed input S-shaper and the PID controller was used to control the trolley speed. Jūriniame įvairiarūšiame terminale atliekant konteinerių krovos procesus, vienas iš krantinės kranų valdymo objektų yra vežimėlis. Viena iš problemų, su kuria susiduriama dažniausiai, yra konteinerio svyravimai, kuriuos, be išorinių veiksnių, taip pat sukelia ir vežimėlio judėji-mas. Remdamiesi paskutinių kelerių metų tyrimais, mokslininkai sukūrė įvairių valdymo algoritmų, kurie laboratorinėmis sąlygomis spren-džia atskiras krantinės kranų valdymo problemas. Tačiau kompleksinių ir efektyvių valdymo algoritmų ir jų valdymo sistemos parametrų nustatymo metodai vis dar kuriami ir tobulinami. Šiame darbe sudarytas krantinės krano vežimėlio su kabančiu kroviniu mechanizmo sis-temos matematinis modelis. Šis modelis realizuotas Matlab Simulink aplinkoje ir sprendžiamas taikant Dormand-Prince metodą. Sukurtas laboratorinio krantinės krano valdymo sistemos kompiuterinis modelis skirtas uždarosios valdymo sistemos PID valdiklio parametrams nustatyti, kai užduoties signalui taikomas S formos greičio kitimo profilis. Darbe pateiktas sistemos dinaminis modelis, aprašyta uždaroji valdymo sistema, pateikti kompiuterinio modeliavimo rezultatai, kuriuos planuojama panaudoti kaip pradinę informaciją realaus krano PID valdiklio parametrams derinti. Atlikta simuliacija naudojant nustatytas vertes ir įvertinti krovinio svyravimai taikant S formos greičio kitimo profilį kartu su PID valdikliu vežimėlio greičiui valdyti.

Robust nonfragile observer-based H2/H∞ controller

2016 ◽  
Vol 24 (4) ◽  
pp. 722-738 ◽  
Author(s):  
Atta Oveisi ◽  
Tamara Nestorović
Keyword(s):  
Control System ◽  
Real Time ◽  
Closed Loop ◽  
Linear Time ◽  
Sufficient Conditions ◽  
Loop System ◽  
Linear Matrix ◽  
Closed Loop System ◽  
Real Time System ◽  
Structured Uncertainty

A robust nonfragile observer-based controller for a linear time-invariant system with structured uncertainty is introduced. The [Formula: see text] robust stability of the closed-loop system is guaranteed by use of the Lyapunov theorem in the presence of undesirable disturbance. For the sake of addressing the fragility problem, independent sets of time-dependent gain-uncertainties are assumed to be existing for the controller and the observer elements. In order to satisfy the arbitrary H2-normed constraints for the control system and to enable automatic determination of the optimal [Formula: see text] bound of the performance functions in disturbance rejection control, additional necessary and sufficient conditions are presented in a linear matrix equality/inequality framework. The [Formula: see text] observer-based controller is then transformed into an optimization problem of coupled set of linear matrix equalities/inequality that can be solved iteratively by use of numerical software such as Scilab. Finally, concerning the evaluation of the performance of the controller, the control system is implemented in real time on a mechanical system, aiming at vibration suppression. The plant under study is a multi-input single-output clamped-free piezo-laminated smart beam. The nominal mathematical reduced-order model of the beam with piezo-actuators is used to design the proposed controller and then the control system is implemented experimentally on the full-order real-time system. The results show that the closed-loop system has a robust performance in rejecting the disturbance in the presence of the structured uncertainty and in the presence of the unmodeled dynamics.

Robust Piecewise-Linear State Observers for Flexible Link Mechanisms

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Roberto Caracciolo ◽  
Dario Richiedei ◽  
Alberto Trevisani
Keyword(s):  
Nonlinear Model ◽  
Closed Loop ◽  
Linear Models ◽  
Piecewise Linear ◽  
Equilibrium Points ◽  
Loop System ◽  
State Variables ◽  
Flexible Link ◽  
Closed Loop System ◽  
State Observers

This paper tackles the problem of designing state observers for flexible link mechanisms: An investigation is made on the possibility of employing observers making use of suitable piecewise-linear truncated dynamics models. A general and novel approach is proposed, which provides an objective way of synthesizing observers preventing the instability that may arise from using reduced-order linearized models. The approach leads to the identification of the regions of the domain of the state variables where the linear approximations of the nonlinear model can be considered acceptable. To this purpose, first of all, the stability of the equilibrium points of the closed-loop system is assessed by applying the eigenvalue analysis to appropriate piecewise-linear models. Admittedly, the dynamics of such a closed-loop system is affected by the perturbation of the poles caused by spillover and by the discrepancies between the linearized models of the plant and the one of the observer. Additionally, when nodal elastic displacements and velocities are not bounded in the infinitesimal neighborhoods of the equilibrium points, the difference between the nonlinear model and the locally linearized one is expressed in terms of unstructured uncertainty and stability is assessed through H∞ robust analysis. The method is demonstrated by applying it to a closed-chain flexible link mechanism.

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