Design Of Feedback Control Systems Research Articles

A novel design of feedback control system for plasma horizontal position in IR-T1 tokamak

Determination of accurate plasma horizontal position during plasma discharge is essential to transport it to a control system based on feedback. By using the plasma-circuits linearized model, Proportional Integral Derivative (PID) based controllers and a first order transfer function representing the power supply (PS) dynamics of vertical coil system for IR-T1 tokamak, we analyzed step feedback response of the overall system of IR-T1 tokamak and corresponding Bode diagrams for two cases with and without the plasma resistance and the eddy currents distribution. Also we did experiments for determination of plasma horizontal displacement in this tokamak. This work is done by four magnetic probes that are installed on the circular contour of the tokamak. This data used as input to the feedback controller to validate the performance of it. Results of feedback response analysis show that the controller has good performance. Due to approximations in the controller design, construction, installation and implementation of the controller is necessary and this is the purpose of our future works.

Design and Analog Circuit Implementation of a Dynamic Feedback Control System Based on RLC Series Circuit

Design and Analog Circuit Implementation of a Dynamic Feedback Control System Based on RLC Series Circuit

Controller design for multivariable nonlinear control systems based on gradient-based ant colony optimisation

In the present study, a swarm intelligent algorithm called gradient-based continuous ant colony optimisation (GCACO) was utilised for controller design in multi-variable nonlinear control systems. The time domain objectives subject to the frequency domain constraints were considered in the proposed procedure. In order to be able to incorporate the time domain requirements in an overall controller design technique, the appropriate linearisation techniques utilised here was the exponential input describing function (EIDF). Experimental results obtained showed that GCACO technique developed here for controller design of nonlinear multivariable feedback control systems was capable to produce optimal and practical controllers that meet the design requirement in an efficient manner and computationally acceptable amount of time.

Simulation and design of feedback control on resistive wall modes in Keda Torus eXperiment

The feedback control of resistive wall modes (RWMs) in Keda Torus eXperiment (KTX) (Liu et al., Plasma Phys. Controlled Fusion 56, 094009 (2014)) is investigated by simulation. A linear model is built to describe the growth of the unstable modes in the absence of feedback and the resulting mode suppression due to feedback, given the typical reversed field pinch plasma equilibrium. The layout of KTX with two shell structures (the vacuum vessel and the stabilizing shell) is taken into account. The feedback performance is explored both in the scheme of “clean mode control” (Zanca et al., Nucl. Fusion 47, 1425 (2007)) and “raw mode control.” The discrete time control model with specific characteristic times will mimic the real feedback control action and lead to the favored control cycle. Moreover, the conceptual design of feedback control system is also presented, targeting on both RWMs and tearing modes.

Data-Driven Design and Optimization of Feedback Control Systems for Industrial Applications

In this paper, regarding the observer form of the well-known Youla parameterization, the controller design and optimization are exhibited with an integrated residual access. To better reveal this philosophy, the feedback control loop is interpreted on the basis of the observer-based residual generator. The next main attention is drawn to the generation of residuals, the design of a deadbeat controller for system stabilization both in the data-driven environment, and later the optimal adaptive realization of a dynamic system that translates residuals into compensatory control inputs to meet certain performance specifications. Towards these goals, numerical algorithms are summarized, and for the issues of controller optimization, the reinforcement learning algorithm is introduced using only measured input-output and residual signals. In addition, the effectiveness of developed schemes for industrial applications is also illustrated by experimental studies on a laboratory continuous stirred tank heater (CSTH) process.

Data-driven realizations of kernel and image representations and their application to fault detection and control system design

This paper deals with the data-driven design of observer-based fault detection and control systems. We first introduce the definitions of the data-driven forms of kernel and image representations. It is followed by the study of their identification. In the context of a fault-tolerant architecture, the design of observer-based fault detection, feed-forward and feedback control systems are addressed based on the data-driven realization of the kernel and image representations. Finally, the main results are demonstrated on the laboratory continuous stirred tank heater (CSTH) system.

Robust Stabilization of Micro Aerial Vehicles with Uncertain Actuator Nonlinearities

Low cost actuators and linkages used in Micro Aerial Vehicles will lead to unmodeled nonlinearities like dead zone and backlash in the actuator. These actuator nonlinearities are often neglected in the design of feedback control system and can detoriate the system performance remarkably. This paper presents the design of robust control laws for Micro Aerial vehicles (MAV) using sliding mode control approach to deal with nonlinear uncertain plant models. The uncertainties can be in the form of parametric variations, external disturbances or uncertain actuator nonlinearities. The uncertainties are assumed to be bounded with known values. Simulation has been carried out using MAV 6 DoF nonlinear model and the results are provided to check the performance of the control laws.

Analysis of Linear Quantum Optical Networks

This paper is concerned with the analysis of linear quantum optical networks. It provides a systematic approach to the construction a model for a given quantum network in terms of a system of quantum stochastic differential equations. This corresponds to a classical state space model. The linear quantum optical networks under consideration consist of interconnections between optical cavities, optical squeezers, and beamsplitters. These models can then be used in the design of quantum feedback control systems for these networks.

Time Response Options for Structural Damage Mitigation Using an Actuator Load

It is well known that time responses in a single input system cannot be altered under a state variable based feedback control system design. The closed loop eigenvector options assignable using the linear state feedback controller is fixed in single input systems. As a result, time responses are also fixed. However, when state derivative feedback is augmented, similar to a multiple input system, several closed loop eigenvector options are possible. Hence, it allows time response shaping available in the single input systems. In this paper, a novel procedure to design simultaneous state and state derivative feedback controller for single input systems is presented. Then to illustrate its utility, structural damage growth mitigation (active structural prognosis) using time response shaping under a structural load is illustrated. It is shown that the life of the damaged structure in a dynamic environment is possible to extend using time response options resulting from a typical state/state derivative feedback controller. A discrete dynamic structure is considered to illustrate the underlying principles of active structural prognosis.

Fast‐rate output feedback control system design with adaptive output estimator for nonuniformly sampled multirate systems

SUMMARYMultirate sampled system can be seen in many industries and several kinds of control method using lifting method have been proposed. Unfortunately, it was difficult to deal with nonuniformly sampled multirate systems. In this paper, we will propose a design scheme of output feedback control with a simple structure for nonuniformly sampled systems based on almost strictly positive real properties. A design method of a fast‐rate output feedback control system for nonuniformly sampled multirate systems with a fast uniform input updating rate and slow nonuniform output sampling rates. An adaptive output estimator will be proposed so as to realize a fast‐rate output feedback control for nonuniformly sampled systems at the fast sampling period of the input updating rate, and then, a design scheme of a fast‐rate adaptive output feedback control at the fast sampling period of the input updating rate will be proposed for nonuniformly sampled systems utilizing the proposed adaptive output estimator. We also analyze the stability of the obtained fast‐rate output feedback control system based on almost strictly positive real properties of the controlled system. Copyright © 2013 John Wiley & Sons, Ltd.

Optimal causal control of a wave energy converter in a random sea

This paper concerns the design of feedback control systems to maximize power generation of a wave energy converter (WEC) in a random sea. In the literature on WEC control, most of the proposed feedback controllers fall into three categories. Many are static; i.e., they extract power by imposing an equivalent damping or resistive load on the power take-off (PTO) devices. Others are dynamic and are designed to maximize power generation at all frequencies, which results in an anticausal feedback law. Other dynamic control design methods are causal, and are tuned to achieve the anticausal performance at only a single frequency. By contrast, this paper illustrates that the determination of the true optimal causal dynamic controller for a WEC can be found as the solution to a nonstandard linear quadratic Gaussian (LQG) optimal control problem. The theory assumes that the control system must make power generation decisions based only on present and past measurements of the generator voltages and/or velocities. It is shown that unlike optimal anticausal control, optimal causal control requires knowledge of the stationary spectral characteristics of the random sea state. Additionally, it is shown that the efficiency of the generator factors into the feedback synthesis. The theory is illustrated on a linear dynamical model for a buoy-type WEC with significant resonant modes in surge and pitch, and equipped with three spatially-distributed generators.

Analysis and Design of Robust Feedback Control Systems for a Nonlinear Two-Wheel Inverted Pendulum system

Two-wheel inverted pendulum is an open loop unstable system, and is a nonlinear system. But can use at many practice application, like SEGWAY etc. This paper research the theorems nonlinear property of the two-wheel inverted pendulum model and simulation its nonlinear output response. Simulation results show that system has robustness. Can maintain stable when suffer nonlinear inference and not change controller gain, And if we design a gain compensator controller cause by nonlinear property influence, simulation result show can improve the two-wheel inverted pendulum output response.

Systematic design and simulation of a tearing mode suppression feedback control system for the TEXTOR tokamak

Suppression of tearing modes is essential for the operation of tokamaks. This paper describes the design and simulation of a tearing mode suppression feedback control system for the TEXTOR tokamak. The two main control tasks of this feedback control system are the radial alignment of electron cyclotron resonance heating and current drive (ECRH/ECCD) with a tearing mode and the stabilization of a mode at a specific width. In order to simulate these control tasks, the time evolution of a tearing mode subject to suppression by ECRH/ECCD and destabilization by a magnetic perturbation field is modelled using the generalized Rutherford equation. The model includes an equilibrium model and an ECRH/ECCD launcher model. The dynamics and static equilibria of this model are analysed. The model is linearized and based on the linearized model, linear feedback controllers are designed and simulated, demonstrating both alignment and width control of tearing modes in TEXTOR.

A Control Systems Approach to Input Estimation with Hydrological Applications

This paper demonstrates the feasibility of a new approach to system inversion and input signal estimation based on the exploitation of non-minimal state space feedback control system design methods that can be applied to non-minimum phase and unstable systems. The real and simulated examples demonstrate its practical utility and show that it has particular relevance in a hydrological systems context.

Persistence Filters for Estimation: Applications to Control in Shared-Sensing Reversible Transducer Systems

We investigate state observer and feedback control design for systems with state- and time-dependent control or measurement gains. In this framework, we look at reversible transducers that are continually switched between the actuation and sensing modes at some prespecified schedule. Design and analysis of stable state-observers and feedback controllers for these classes of switched/hybrid systems are significantly complicated by the fact that, at any given instant of time, the overall system loses either controllability (during the sensing phase) or observability (during the actuation phase). In this work, we consider systems with scalar time-varying measurement gains and provide a novel observer construction that guarantees exponential reconstruction of state estimates to their true values. We go a step further to derive an exponentially stabilizing controller design that uses the state estimates resulting from our observer. This amounts to the establishment of a rather remarkable separation property of the control design. These developments hinge on a rather mild technical assumption, which can be interpreted for the reversible transducer problem as a persistent dwell time for both the sensing and actuation modes. An important feature here is that the convergence rate can be specified to any arbitrary value. Our theoretical results are validated through numerical simulations of challenging test-cases that include open-loop unstable systems. The paper also illustrates potential for nonlinear extensions of the observer based control design by considering an interesting special case.

PI Sliding Mode Control for Mismatched Uncertain Systems

This paper focused on the proportional–integral sliding mode control for uncertain dynamic systems with mismatch uncertainties. First, the switching surface condition for the sliding mode control is synthesized. Then the control law is designed to drive the state trajectories of the system onto the sliding surface and the system remains in it thereafter. The proposed control law is applied to a numerical example and its performance is compared to the state variable feedback control system design methodology. Key words: sliding mode control; state variable feedback regulator; mismatched uncertainties

An Application of the Individual Channel Analysis and Design Approach to Control of a Two-input Two-output Coupled-tanks System

Frequency-domain methods have provided an established approach to the analysis and design of single-loop feedback control systems in many application areas for many years. Individual Channel Analysis and Design (ICAD) is a more recent development that allows neo-classical frequency-domain analysis and design methods to be applied to multi-input multi-output control problems. This paper provides a case study illustrating the use of the ICAD methodology for an application involving liquid-level control for a system based on two coupled tanks. The complete nonlinear dynamic model of the plant is presented for a case involving two input flows of liquid and two output variables, which are the depths of liquid in the two tanks. Linear continuous proportional plus integral controllers are designed on the basis of linearised plant models to meet a given set of performance specifications for this two-input two-output multivariable control system and a computer simulation of the nonlinear model and the controllers is then used to demonstrate that the overall closed-loop performance meets the given requirements. The resulting system has been implemented in hardware and the paper includes experimental results which demonstrate good agreement with simulation predictions. The performance is satisfactory in terms of steady-state behaviour, transient responses, interaction between the controlled variables, disturbance rejection and robustness to changes within the plant. Further simulation results, some of which involve investigations that could not be carried out in a readily repeatable fashion by experimental testing, give support to the conclusion that this neo-classical ICAD framework can provide additional insight within the analysis and design processes for multi-input multi-output feedback control systems.

Development of a Customized Autopilot for Unmanned Helicopter Model Using Genetic Algorithm via the Application of Different Guidance Strategies

The objective of this paper is to develop a customized autopilot system that enables a helicopter model to carry out an autonomous flight using on-board microcontroller. The main goal of this project is to provide a comprehensive controller design methodology, Modeling, simulation, guidance and verification for an unmanned helicopter model. The autopilotsystem was designed to demonstrate autonomous maneuvers such as flying over the planned waypoints with constant forward speed and considerable steep maneuvers. For the controller design, the nonlinear dynamic model of the Remote Control helicopter was built by employing Lumped Parameter approach comprising of four different subsystems such as actuator dynamics, rotary wing dynamics, force and moment generation process and rigid body dynamics. The nonlinear helicopter mathematical model was then linearized using small perturbation theory for stability analysis and linear feedback control system design. The linear state feedback for the stabilization and control of the helicopter was derived using Pole Placement Method. The overall dynamic system control with output feedback was computed using Genetic Algorithm. Series of Matlab-Simulink models and guidance algorithms were presented in this work to simulate and verify the autopilot system performance. The proposed autopilot has shown acceptable capability of stabilizing and controlling the helicopter during tracking the desired waypoints. This paper is presenting a detailed comparison study for two different guidance strategies. The first strategy is concerning the difference between the desired heading or elevation referred to the next waypoint and the actual heading or elevation of the unmanned helicopter model. The second strategy is concerning the relative distance between the actual and the desired trajectories. In other words the first method is tracking the waypoints while the second one is tracking the trajectory. In this work a comparison study was conducted through the mentioned strategies simulation to show the significant differences in the output performance. Some performance indexes were presented to evaluate the system performance errors and the control effort needed for both strategies using the same desired trajectory and the same waypoints.

Feedback Control Design for Systems with x-Discontinuous Right-Hand Side

The problem of the admissible feedback synthesis for nonlinear systems with discontinuous right-hand side is considered. Sufficient conditions for solvability of this problem are proved. The neighborhood of the origin is broken in a finite number of domains G 1,G 2,…,G k . In each G j a control system $\dot{x}=f_{j}(x,u)$ is given. The problem of the admissible feedback synthesis is completely studied for control systems of the form $\dot{x}=a_{j}(x)+\gamma_{j}(x,u) b_{j}(x)$ , where $u\in \Omega_{j} \subset \Bbb{R}$ for x∈G j . The controllability function method is used to construct the feedback control.

Robust control application for a three-axis road simulator

This paper presents the design of a quantitative feedback control system for a three-axis hydraulic road simulator. The road simulator is a multiple input-output (MIMO) system with parameter uncertainties which should be compensated with a robust control method. The objective of the present paper is to reproduce the random input signal or real road vibration signal by three hydraulic cylinders. The re- placed m 2 MISO equivalent control system is suggested, which satisfies the design specification of the original mxm MIMO control sys- tem by decoupling each of the three axes. Quantitative Feedback Theory (QFT) is used to control the simulator. The QFT illustrates a tracking performance of the closed-loop controller with low order transfer function G (s) and pre-filter F (s) having the minimum band- width for the uncertain plant with parameter uncertainty. The efficacy of the designed controller is verified through dynamic simulation, which is co-simulated with hydraulic models of Matlab and Adams multi-body. The simulation and the experimental results show that the proposed control technique works well for uncertain hydraulic plant systems.