scholarly journals Design of Switching Multiobjective Controller: A New Approach

2011 ◽  
Vol 2011 ◽  
pp. 1-12
Author(s):  
Ahmad Fakharian
Keyword(s):  
Closed Loop ◽  
Multiplicative Noise ◽  
Loop System ◽  
Switching System ◽  
Closed Loop System ◽  
New Approach ◽  
Output Feedback Controller ◽  
The Stability ◽  
Fuzzy Supervisor ◽  
Globally Stable

Design of switching / output-feedback controller for discrete-time LTI systems with state-multiplicative noise is considered. The closed loop system achieves a minimum bound on the stochastic performance level, while satisfying the performance. The proposed controller is based on a fuzzy supervisor which manages the combination of two separate and controllers. A convex formulation of the two controllers leads to a structure which benefits from the advantages of both controllers to ensure a good performance in both the transient phase ( controller) and the steady phase ( controller). The stability analysis uses the Lyapunov technique, inspired from switching system theory, to prove that the closed loop system with the proposed controller structure remains globally stable despite the configuration changing.

A Simple Structure for Bilateral Transparent Teleoperation Systems With Time Delay

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Alireza Alfi ◽  
Mohammad Farrokhi
Keyword(s):  
Time Delay ◽  
Closed Loop ◽  
Simple Structure ◽  
Finite Impulse Response ◽  
Structure Design ◽  
Loop System ◽  
Bilateral Teleoperation ◽  
Closed Loop System ◽  
The Stability ◽  
Teleoperation Systems

This paper presents a simple structure design for bilateral teleoperation systems with uncertainties in time delay in communication channel. The goal is to achieve complete transparency and robust stability for the closed-loop system. For transparency, two local controllers are designed for the bilateral teleoperation systems. One local controller is responsible for tracking the master commands, and the other one is in charge of force tracking as well as guaranteeing the stability of the closed-loop system in the presence of uncertainties in time delay. The stability analysis will be shown analytically for two cases: (I) the possibly stability and (II) the intrinsically stability. Moreover, in Case II, in order to generate the proper inputs for the master controller in the presence of uncertainties in time delay, an adaptive finite impulse response (FIR) filter is designed to estimate the time delay. The advantages of the proposed method are threefold: (1) stability of the closed-loop system is guaranteed under some mild conditions, (2) the whole system is transparent, and (3) design of the local controllers is simple. Simulation results show good performance of the proposed method.

Mode Decoupling Controller for Feedback Model Updating

2004 ◽  
Author(s):  
Hunsang Jung ◽  
Youngjin Park ◽  
K. C. Park
Keyword(s):  
Closed Loop ◽  
Model Updating ◽  
Control Method ◽  
Loop System ◽  
Mode Shapes ◽  
Closed Loop System ◽  
Sensitivity Matrix ◽  
Data Set ◽  
Conventional Methods ◽  
The Stability

A novel concept of feedback loop design for modal test and model updating is proposed. This method uses the closed-loop frequency information for parameter modifications to overcome the problems associated with the conventional methods employing the modal sensitivity matrix. To obtain new modal information from the closed-loop system, controllers should be effective in changing modal data while guaranteeing the stability of the closed-loop system. The present paper proposes a mode-decoupling controller that can alter a target mode while guaranteeing the stability of the closed-loop, and that can be constructed by using the measured open-loop, mode shapes. A simulation based on time domain input/output data is performed to evaluate the feasibility of the proposed control method, which is subsequently corroborated via experiments. Experimental data obtained on a beam via the proposed mode-decoupling controller have been applied to estimate thicknesses of a beam. The results show that the proposed approach outperforms conventional methods with a far less number of data set for the estimation of system parameters.

scholarly journals Robust LFC Strategy for Wind Integrated Time-Delay Power System Using EID Compensation

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3223 ◽  
Author(s):  
Liu ◽  
Zhang ◽  
Zou
Keyword(s):  
Time Delay ◽  
Power System ◽  
Closed Loop ◽  
Frequency Control ◽  
Loop System ◽  
Load Frequency Control ◽  
System Stability ◽  
Linear Matrix ◽  
Closed Loop System ◽  
The Stability

This paper presents an active disturbance rejection control (ADRC) technique for load frequency control of a wind integrated power system when communication delays are considered. To improve the stability of frequency control, equivalent input disturbances (EID) compensation is used to eliminate the influence of the load variation. In wind integrated power systems, two area controllers are designed to guarantee the stability of the overall closed-loop system. First, a simplified frequency response model of the wind integrated time-delay power system was established. Then the state-space model of the closed-loop system was built by employing state observers. The system stability conditions and controller parameters can be solved by some linear matrix inequalities (LMIs) forms. Finally, the case studies were tested using MATLAB/SIMULINK software and the simulation results show its robustness and effectiveness to maintain power-system stability.

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 Operational Space Control of a Lightweight Robotic Arm Actuated by Shape Memory Alloy (SMA) Wires

2016 ◽  
Author(s):  
Serket Quintanar-Guzmán ◽  
Somasundar Kannan ◽  
Miguel A. Olivares-Mendez ◽  
Holger Voos
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Closed Loop ◽  
Loop System ◽  
Robotic Arm ◽  
Control Law ◽  
Closed Loop System ◽  
End Effector ◽  
Position Regulation ◽  
The Stability

This paper presents the design and control of a two link lightweight robotic arm using a couple of antagonistic Shape Memory Alloy (SMA) wires as actuators. A nonlinear robust control law for accurate positioning of the end effector of the two-link SMA based robotic arm is developed to handle the hysteresis behavior present in the system. The model presented consists of two subsystems: firstly the SMA wires model and secondly the dynamics of the robotic arm itself. The control objective is to position the robotic arm’s end effector in a given operational plane position. For this regulation problem a sliding mode control law is applied to the hysteretic system. Finally a Lyapunov analysis is applied to the closed-loop system demonstrating the stability of the system under given conditions. The simulation results demonstrate the accurate and fast response of the control law for position regulation. In addition, the stability of the closed-loop system can be corroborated.

Position/force control of robot manipulators using reinforcement learning

2019 ◽  
Vol 46 (2) ◽  
pp. 267-280 ◽  
Author(s):  
Adolfo Perrusquía ◽  
Wen Yu ◽  
Alberto Soria
Keyword(s):  
Reinforcement Learning ◽  
Force Control ◽  
Closed Loop ◽  
Position Error ◽  
Loop System ◽  
Closed Loop System ◽  
Content Type ◽  
Impedance Model ◽  
Impedance Parameters ◽  
The Stability

Purpose The position/force control of the robot needs the parameters of the impedance model and generates the desired position from the contact force in the environment. When the environment is unknown, learning algorithms are needed to estimate both the desired force and the parameters of the impedance model. Design/methodology/approach In this paper, the authors use reinforcement learning to learn only the desired force, then they use proportional-integral-derivative admittance control to generate the desired position. The results of the experiment are presented to verify their approach. Findings The position error is minimized without knowing the environment or the impedance parameters. Another advantage of this simplified position/force control is that the transformation of the Cartesian space to the joint space by inverse kinematics is avoided by the feedback control mechanism. The stability of the closed-loop system is proven. Originality/value The position error is minimized without knowing the environment or the impedance parameters. The stability of the closed-loop system is proven.

A Theoretical Control Strategy for a Diesel Engine

2005 ◽  
Vol 128 (2) ◽  
pp. 453-457 ◽  
Author(s):  
R. Outbib ◽  
X. Dovifaaz ◽  
A. Rachid ◽  
M. Ouladsine
Keyword(s):  
Diesel Engine ◽  
Engine Speed ◽  
Closed Loop ◽  
Lyapunov Theory ◽  
Loop System ◽  
Control Law ◽  
Closed Loop System ◽  
Nonlinear Method ◽  
New Approach ◽  
Fuel Rate

In this paper we present a theoretical strategy for diesel engine control. More precisely, we propose a new approach to control the speed of the engine using the fuel rate as the control law and we show how this approach can be used to control the opacity. We first establish a mathematical model that describes the behavior of the engine. Afterward, we propose a new nonlinear method to design a controller for a class of nonlinear systems. The proposed method, based on Lyapunov theory, is used to design a smooth feedback law that renders the closed-loop system asymptotically stable around a desired engine speed value. Finally, simulation results are proposed to highlight the performances of the closed-loop system.

An Approach to Telerobotic Manipulations

1997 ◽  
Vol 119 (3) ◽  
pp. 431-438 ◽  
Author(s):  
H. Kazerooni ◽  
C. L. Moore
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Sufficient Conditions ◽  
Human Robot Interaction ◽  
Loop System ◽  
Robotic Manipulation ◽  
Closed Loop System ◽  
Robot Interaction ◽  
Minimum Number ◽  
The Stability

This article introduces three areas of study: 1 telefunctioning; 2 a control method for producing telefunctioning; and 3 an analysis of human-robot interaction when telefunctioning governs the system behavior. Telefunctioning facilitates the maneuvering of loads by creating a perpetual sense of the load dynamics for the operator. Telefunctioning is defined as a robotic manipulation method in which the dynamic behaviors of the slave robot and the master robot are functions of each other; these functions are the designer’s choice and depend on the application. (In a subclass of telefunctioning currently referred to as telepresence, these functions are specified as “unity” so that the master and slave variables (e.g., position, velocity) are dynamically equal.) To produce telefunctioning, this work determines a minimum number of functions relating the robots’ variables, and then develops a control architecture which guarantees that the defined functions govern the dynamic behavior of the closed-loop system. The stability of the closed-loop system (i.e., master robot, slave robot, human, and the load being manipulated) is analyzed and sufficient conditions for stability are derived.

Controller Design and Stability Analysis of Output Pressure Regulation in Electrohydrostatic Actuators

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Masoumeh Esfandiari ◽  
Nariman Sepehri
Keyword(s):  
Closed Loop ◽  
Open Loop ◽  
Loop System ◽  
Linear Matrix ◽  
Parametric Uncertainties ◽  
Closed Loop System ◽  
Output Pressure ◽  
Frequency Responses ◽  
Wide Range ◽  
The Stability

In this paper, a robust fixed-gain linear output pressure controller is designed for a double-rod electrohydrostatic actuator using quantitative feedback theory (QFT). First, the family of frequency responses of the system is identified by applying an advanced form of fast Fourier transform on the open-loop input–output experimental data. This approach results in realistic frequency responses of the system, which prevents the generation of unnecessary large QFT templates, and consequently contributes to the design of a low-order QFT controller. The designed controller provides desired transient responses, desired tracking bandwidth, robust stability, and disturbance rejection for the closed-loop system. Experimental results confirm the desired performance met by the QFT controller. Then, the nonlinear stability of the closed-loop system is analyzed considering the friction and leakage, and in the presence of parametric uncertainties. For this analysis, Takagi–Sugeno (T–S) fuzzy modeling and its stability theory are employed. The T–S fuzzy model is derived for the closed-loop system and the stability conditions are presented as linear matrix inequalities (LMIs). LMIs are found feasible and thus the stability of the closed-loop system is proven for a wide range of parametric uncertainties and in the presence of friction and leakages.

Adaptive extended state observer-based flatness nonlinear output control for torque tracking of electrohydraulic loading system

2017 ◽  
Vol 40 (10) ◽  
pp. 2999-3009 ◽  
Author(s):  
Chenghu Jing ◽  
Hongguang Xu ◽  
Xiaoming Song ◽  
Biao Lu
Keyword(s):  
Closed Loop ◽  
State Observer ◽  
High Accuracy ◽  
Loop System ◽  
Extended State Observer ◽  
Extended State ◽  
Closed Loop System ◽  
Output Control ◽  
Loading System ◽  
The Stability

Electrohydraulic loading system is a torque servo system with high-accuracy and high-frequency response. In this paper, an adaptive extended state observer-based flatness nonlinear output control is proposed to improve the torque tracking performance of electrohydraulic loading system. This method combines a flatness concept, expected state, adaptive extended state observer and system output to develop a stable control system. Expected input feedforward based on the flatness property is designed to provide model compensation for bandwidth enhancement. An adaptive extended state observer is proposed to estimate the unmeasured states and the unmodeled dynamics. Based on estimated states and disturbances, state feedback control is developed to ensure the stability of closed-loop system, and to improve torque tracking accuracy and system robustness. The stability of the closed-loop system is proved by the Lyapunov stability theory. Extensive experiments were carried out to verify the performance of high-accuracy tracking of the proposed control strategy.

Sign in / Sign up

Export Citation Format

Share Document