Regional Pole Constraints Research Articles

Optimal control of satellite system model using Linear Matrix inequality approach

In this paper, a robust control strategy has been proposed for the satellite attitude control system, namely, ℋ∞ with regional pole constraints. This design method has been applied to eliminate the effects of disturbances and uncertainties, which are inevitable in aerospace applications. A convex optimization approach using Linear Matrix Inequalities (LMIs) has been utilized in this work. The concept of LMI region constraints have been used to guarantee the closed-loop poles lie within a defined region in the complex plane, which helps improve performance in addition to the robustness properties. Therefore, the designed controller can be viewed as a multi-objective controller that guarantees both robustness and performance. Simulation results demonstrate that the developed controller (ℋ∞ with LMI region constraint) performs better than only ℋ∞ and pole placement controllers, in terms of disturbance attenuation, transient response, and control effort.

Iterative Learning Control for Linear Differential Systems With Additional Performance Requirements

This paper develops the systematic procedure for designing of iterative learning control (ILC) algorithms through the differential repetitive process setting. This means that the proposed approach can be directly applied to plants with differential dynamics and allows to satisfy the additional requirements on the resulting dynamics. In particular, the proposed design procedure enforces a required frequency attenuation over a finite frequency range and includes regional pole constraints. Additionally, an important result extension to the plants with relative degree greater than unity is presented. The sufficient conditions for the existence of the controllers are derived in terms of linear matrix inequalities, which are immediately extended to deal with time varying uncertainties. Finally, the simulations for a typical actuator of tracking servo system prove that the design is effective and brings some advantages when compared to the existing alternatives.

LPV gain-scheduled attitude control for satellite with time-varying inertia

The performance of an attitude control system is impacted by the inertia change, especially for small satellites. Although there are various control methods for satellites with inertia uncertainties, very few controllers are designed with consideration of time-varying inertia. In this paper, a linear parameter varying (LPV) model is established for a satellite with time-varying inertia. Moreover, because of their common occurrences, the actuator faults and saturation are considered during the controller design. A gain-scheduled controller is developed to guarantee the steady-state and transient performance of the system by limiting the steady-state variance and regional pole constraints. The simulations indicate that the proposed controller improves the stability performance by adjusting the gain with the inertia variations.

Fault‐tolerant control for wireless networked control systems with an integrated scheduler

SummaryThis paper addresses a study of fault‐tolerant control (FTC) for wireless networked control systems (WNCSs) in industrial automatic processes. The WNCSs is composed of many subsystems, which operate with different sampling cycles. In order to meet the real‐time requirements and ensure a deterministic data transmission, the time division multiple access (TDMA) mechanism is adopted in WNCSs. The data in WNCSs are transmitted following a TDMA‐based scheduler. According to the periodicity, WNCSs integrated with the scheduler is first formulated as discrete linear time periodic systems (LTPSs). Afterwards, a fault estimation method for LTPSs is developed under a H∞ performance specification with a regional pole constraint. With the achieved state observer and fault estimator, an FTC strategy for LTPSs is explored. Finally, the proposed methods are verified on a physical experimental WiNC platform. Copyright © 2016 John Wiley & Sons, Ltd.

Reduced-order controller synthesis with regional pole constraint

ABSTRACTA reduced order output feedback controller is designed for a linear time invariant system, which guarantees that the closed-loop poles are placed within some pre-specified stability region in the complex plane. A convex approximation of the non-convex constraints is used to pose a sequence of semi-definite programs, which provide the lowest order proper controller satisfying the approximate constraints. The proposed method is demonstrated on two practical controller design applications.

Fault reconstruction in descriptor linear parameter-varying systems via polytopic unknown-input proportional-integral observers

SUMMARY In this paper, a fault reconstruction scheme for a class of discrete-time descriptor linear parameter-varying systems is investigated. A discrete-time polytopic descriptor linear parameter-varying system subject to external disturbances and actuator faults is first established; then, using H∞ techniques and regional pole constraints, a novel polytopic unknown-input proportional-integral observer is constructed to simultaneously reconstruct system states and actuator faults. Existence conditions for the new polytopic unknown-input proportional-integral observer are explicitly derived. The stability and convergence of the presented observer are proved through Lyapunov theory and linear matrix inequalities. Using a slack-matrix-variable technique, less conservative results for observer design are obtained. At last, an illustrative example is simulated to verify the effectiveness of the proposed fault reconstruction approach. Copyright © 2014 John Wiley & Sons, Ltd.

An Age Estimation Method to Panoramic Radiographs from Indonesian Individuals

This paper presents multiobjective H 2 /H ∞ control design with regional pole constraints . The state feedback gain can be obtained by solving a linear matrix inequality (LMI) feasibility problem that robustly assigns the closed-loop poles in a prescribed LMI region. The proposed technique is illustrated with applications to the design of stabilizer for a typical single-machine infinite-bus (SMIB) power system. The LMI-based control ensures adequate damping for widely varying system operating conditions. The simulation results illustrate the effectiveness and robustness of the proposed stabilizer.

$H_\infty$ Optimization With Pole Constraints of Static Output-Feedback Controllers—A Non-Smooth Optimization Approach

A non-smooth optimization approach for designing constant output-feedback controllers for linear time-invariant systems is considered. The design requirements combine H∞ performance requirements with regional pole constraints. The pole constraints are embedded in the design criterion using a transformation on the system model which modifies the H∞-norm of the closed-loop system via a barrier function that is related to the closed-loop poles damping. The method is applied to various flight control examples.

A framework of robust fault estimation observer design for continuous‐time/discrete‐time systems

SUMMARYA design framework of the observer‐based robust fault estimation for continuous‐time/discrete‐time systems is presented in this paper. Firstly, a multiconstrained fault estimation observer under the H∞ performance specification with the regional pole constraint is proposed to achieve robust fault estimation. Then, the existence conditions for both continuous‐time/discrete‐time systems are derived explicitly. Furthermore, by introducing slack variables, improved results on the multiconstrained fault estimation observer design are obtained such that different Lyapunov functions can be separately designed for each constraint. Finally, simulation results of a vertical takeoff and landing aircraft are presented to illustrate our contributions. Copyright © 2012 John Wiley & Sons, Ltd.

Multiobjective H2/H∞ Control Design with Regional Pole Constraints

This paper presents multiobjective H 2 /H ∞ control design with regional pole constraints . The state feedback gain can be obtained by solving a linear matrix inequality (LMI) feasibility problem that robustly assigns the closed-loop poles in a prescribed LMI region. The proposed technique is illustrated with applications to the design of stabilizer for a typical single-machine infinite-bus (SMIB) power system. The LMI-based control ensures adequate damping for widely varying system operating conditions. The simulation results illustrate the effectiveness and robustness of the proposed stabilizer.

Multiobjective H2/H? Control Design with Regional Pole Constraints

Multiobjective H2/H? Control Design with Regional Pole Constraints

Multiobjective H2/H? Control Design with Regional Pole Constraints

This paper presents multiobjective H 2 /H ? control design with regional pole constraints. The state feedback gain can be obtained by solving a linear matrix inequality (LMI) feasibility problem that robustly assigns the closed-loop poles in a prescribed LMI region. The proposed technique is illustrated with applications to the design of stabilizer for a typical single-machine infinite-bus (SMIB) power system. The LMI-based control ensures adequate damping for widely varying system operating conditions. The simulation results illustrate the effectiveness and robustness of the proposed stabilizer.

Guaranteed-cost reliable control with regional pole placement of a power system

This paper deals with the simultaneous coordinated design of power system stabilizer (PSS) and the flexible ac transmission systems (FACTS) controller. The problem of guaranteed cost reliable control with regional pole constraint against actuator failures is investigated. The state feedback controllers are designed to guarantee the closed loop system satisfying the desired pole region, thus achieving satisfactory oscillation damping and settling time, and having the guaranteed cost performance simultaneously. The proposed controllers satisfy desired dynamic characteristics even in faults cases. The controller's parameters are obtained using the linear matrix inequalities (LMI) optimization. Simulation results validate the effectiveness of this approach.

Multi-Objective Fault-Tolerant Output Tracking Control of a Flexible Air-Breathing Hypersonic Vehicle

This paper deals with the problem of multi-objective fault-tolerant output tracking control for the longitudinal model of a flexible air-breathing hypersonic vehicle (FAHV). There exist some challenges for control design for the vehicles due to the inherent couplings between the propulsion system, the airframe dynamics, and the presence of strong flexibility effects. This paper addresses the problem of guaranteed cost fault-tolerant output tracking control with regional pole constraints against actuator faults for the FAHV system. A non-linear longitudinal model is adopted for control design because of the complexity of the FAHV systems. First, a linearized model is established around the trim point including the state of altitude, velocity, angle of attack, pitch angle, and pitch rate, etc. for a non-linear, dynamically coupled simulation model of a FAHV with the aim to address the multi-objective fault-tolerant output tracking control problem. Second, the control objective and models of actuator faults are presented. Third, by utilizing the Lyapunov functional approach, a multi-objective analysis condition is proposed in terms of convex optimization problems, that can be easily solved via standard numerical software. Then, a multi-objective fault-tolerant controller is designed such that the resulting closed-loop system is asymptotically stable and satisfies a prescribed performance cost with the simultaneous consideration of poles assignment in spite of possible actuator failure. Finally, the simulation results are given to show the effectiveness of the proposed method, which is verified by an excellent altitude reference and velocity tracking performance.

Multiobjective H2/H∞ control design with regional pole constraints for damping power system oscillations

; > This paper presents multiobjective H 2 /H ∞ control design with regional pole constraints for damping power system oscillations. The state feedback gain can be obtained by solving a linear matrix inequality (LMI) feasibility problem that robustly assigns the closed-loop poles in a prescribed LMI region. The proposed technique is illustrated with applications to the design of stabilizer for a typical single-machine infinite-bus (SMIB) power system. The LMI-based control ensures adequate damping for widely varying system operating conditions. The simulation results illustrate the effectiveness and robustness of the proposed stabilizer. Keywords: multiobjective H 2 / H ∞ control, regional pole constraints, linear matrix inequality, power system stabilizer, robust control

Static H∞ Optimal Output-feedback of Linear Systems with Pole Constraints – A Non-smooth Optimization Approach

A non-smooth optimization approach for designing a constant output feedback controller for a linear time-invariant system is considered. The design requirements combine both H∞ performance requirements together with regional pole constraints. The pole constraints are embedded in the design criterion using a transformation on the system model which modifies the H∞ -norm of the closed-loop system via a barrier function that is related to the closed-loop poles damping. The method is applied to a flight control example.

LMI-based robustH2 control design with regional pole constraints for damping power system oscillations

This paper presents an LMI-based robust H2 control design with regional pole constraints for damping power system oscillations. The proposed controller uses full state feedback. The feedback gain matrix is obtained as the solution of a linear matrix inequality (LMI). The technique is illustrated with applications to the design of stabilizer for a typical single-machine infinite-bus (SMIB) and a multimachine power system. The LMI-based control ensures adequate damping for widely varying system operating conditions and is compared with the conventional power system stabilizer (CPSS). Copyright © 2004 John Wiley & Sons, Ltd.

LMI-Based Mixed H2/H.INF. Controller Design with Regional Pole Constraints for Damping Power System Oscillations

LMI-Based Mixed H2/H.INF. Controller Design with Regional Pole Constraints for Damping Power System Oscillations

Robust mixed H2/H∞ optimal controller design

This paper addresses the problem of dynamic output feedback robust mixed H2 / H∞ norm optimal control with regional pole constraints. The problem can be formulated a optimization problem involving LMI, Linear Matrix Inequalities. The main purpose of the robust optimal control problem is to minimize mixed H2 / H∞, norm of the closed loop transfer function matrix under some constraints. In the other words, the main objectives of the robust optimal control is to minimize mixed H2 / H∞ norm of the closed loop transfer function matrix under the system performance constraints. In this paper, mixed H2 / H∞ performance index is minimized under the constraint of H2 performance, the constraint of H∞ performance and the regional pole placement. Recent years LMI are extensively used in control system synthesis. The synthesis problem is solved via LMI.

A new method for mixed H2/H∞ control with regional pole constraints

AbstractIn this paper, the problem of state feedback mixed H2/H∞ control with regional pole constraints is studied. The constraint region is represented by several algebraic inequalities. This constrained optimization problem cannot be solved via the LMI approach. Based on the barrier method, we instead solve an auxiliary minimization problem to get an approximate solution. We shall show that the obtained minimal solution of the auxiliary minimization problem can be arbitrarily close to the infimal solution of the original problem. An example is provided to illustrate the benefits of the approach. Copyright © 2003 John Wiley & Sons, Ltd.