Controller Design With Fixed Delay-Margin for a LTI Unstable Open-Loop Plant: Case Studies

2014 ◽  
Author(s):  
Rifat Sipahi ◽  
Payam Mahmoodi Nia
Keyword(s):  
Case Studies ◽  
Closed Loop ◽  
Controller Design ◽  
Open Loop ◽  
System Stability ◽  
Marginal Stability ◽  
Guarantee System ◽  
Delay Margin ◽  
Fixed Delay

Around a benchmark open-loop unstable LTI plant with a single delay, we design controllers that create marginal stability of the closed loop at a pre-defined delay margin value τ. These controllers therefore guarantee system stability for all delays less than τ. Case studies covering various scenarios are presented.

Impedance Reduction Controller Design for Mechanical Systems

2013 ◽  
Author(s):  
Hanseung Woo ◽  
Kyoungchul Kong
Keyword(s):  
Case Studies ◽  
Closed Loop ◽  
Controller Design ◽  
Mechanical Impedance ◽  
Open Loop ◽  
Mechatronic Systems ◽  
Closed Loop Systems ◽  
Guaranteed Stability ◽  
Reaction Forces ◽  
Definition Of

Safety is one of important factors in control of mechatronic systems interacting with humans. In order to evaluate the safety of such systems, mechanical impedance is often utilized as it indicates the magnitude of reaction forces when the systems are subjected to motions. Namely, the mechatronic systems should have low mechanical impedance for improved safety. In this paper, a methodology to design controllers for reduction of mechanical impedance is proposed. For the proposed controller design, the mathematical definition of the mechanical impedance for open-loop and closed-loop systems is introduced. Then the controllers are designed for stable and unstable systems such that they effectively lower the magnitude of mechanical impedance with guaranteed stability. The proposed method is verified through case studies including simulations.

A New Iterative Identification and Control Method of Closed-Loop Power System Based on Ambient Signals

2015 ◽  
Vol 798 ◽  
pp. 261-265
Author(s):  
Miao Yu ◽  
Chao Lu
Keyword(s):  
Power System ◽  
Closed Loop ◽  
Control Method ◽  
Controller Design ◽  
Design Method ◽  
Stability Margin ◽  
System Stability ◽  
Iterative Identification ◽  
Effective Performance ◽  
And Control

Identification and control are important problems of power system based on ambient signals. In order to avoid the model error influence of the controller design, a new iterative identification and control method is proposed in this paper. This method can solve model set and controller design of closed-loop power system. First, an uncertain model of power system is established. Then, according to the stability margin of power system, stability theorem is put forward. And then controller design method and the whole algorithm procedure are given. Simulation results show the effective performance of the proposed method based on the four-machine-two-region system.

scholarly journals Experimental Study ofH∞Control of Flexible Plate with Time Delay

2013 ◽  
Vol 20 (2) ◽  
pp. 227-246
Author(s):  
Tong Zhao ◽  
Long-Xiang Chen ◽  
Guo-Ping Cai
Keyword(s):  
Time Delay ◽  
Controller Design ◽  
Experimental Studies ◽  
Parameters Optimization ◽  
System Stability ◽  
Flexible Plate ◽  
Matrix Inequality ◽  
Weighting Matrix ◽  
Guarantee System ◽  
The Matrix

This paper presents theoretical and experimental studies ofH∞control of a flexible plate with time delay. A matrix inequality used for stability analysis is proposed and proved by using the Lyapunov-Krasovskii functional and free-weighting matrix. AnH∞controller is designed based on the matrix inequality and by using the parameter-adjusting method. Three control scenarios are discussed in detail by transforming the problem into parameters optimization: (i) controller design when maximum time delay of the system is known; (ii) allowable time delay when controller is known; (iii) the biggest allowable time delay to guarantee system stability when controller is unknown. Numerical simulations and experiments are also given to demonstrate the validity and feasibility of the proposed methods in this paper.

scholarly journals High Efficient Solar Integrated an Isolated Dc-Dc Full-Bridge Converter for Electric Vehicle Battery Charging Application

2020 ◽  
Vol 9 (4) ◽  
pp. 432-437
Keyword(s):  
Electric Vehicle ◽  
Closed Loop ◽  
Open Loop ◽  
Loop System ◽  
System Stability ◽  
Control Technique ◽  
Closed Loop System ◽  
Conductance Method ◽  
High Efficient ◽  
Electric Vehicle Battery

In this paper, the power from a solar PV panel 20VDC, 12.5ADC is used for charging an electric vehicle battery (12V, 7Ah) with the help of an isolated dc-dc converter in an efficient manner. The power rating maintained in the system is around (200-250) W. The parasitic circuit analysis is carried out theoretically. The zero voltage transition (ZVT) technique is implemented at the inverter stage and an isolation transformer (1:1) is used for source-load isolation purposes. In order to achieve ZVT, a proper design procedure is followed and a pulse triggering technique is carried out at the switching element. The designed values of the parasitic elements are used in the Simulink tool. The open loop and closed loop system of the proposed converter are simulated in MATLAB Simulink package. In the open loop system, an irradiation analysis carried out similarly closed loop has reference voltage variation analysis in order to verify the system stability at the various operating condition. The problem of transients in open loop output is rectified in the closed loop operation. The MPP and PI control technique is initiated in the closed loop system for better performance. The MPP technique used is incremental conductance method for tracking maximum power from the PV array.

Analysis and Control of Multi-Mode Axial Flow Compression System Models1

1999 ◽  
Vol 122 (3) ◽  
pp. 393-401 ◽  
Author(s):  
MingQing Xiao ◽  
Tamer Bas¸ar
Keyword(s):  
Closed Loop ◽  
Controller Design ◽  
Axial Flow ◽  
Pressure Rise ◽  
Open Loop ◽  
Rotating Stall ◽  
Flow Compression ◽  
The Right ◽  
And Control ◽  
Multi Mode

The paper studies the behavior of multi-mode systems of the Moore-Greitzer model. Its main result is the existence of a parameterized nonlinear state feedback controller which stabilizes the system to the right of the peak of the compressor characteristic. In this process, a rotating stall envelope surface is discovered, and it is shown that the controller design achieves the tasks of preventing the closed-loop system from entering either rotating stall or surge, and making the closed-loop pressure rise coefficient be able to approach its maximum. Numerical simulations of the open-loop and closed-loop models are presented to illustrate the analysis and the results. [S0022-0434(00)00803-0]

scholarly journals Model Decoupled Synchronization Control Design with Fractional Order Filter for H-Type Air Floating Motion Platform

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 633
Author(s):  
Yixiu Sun ◽  
Lizhan Zeng ◽  
Ying Luo ◽  
Xiaoqing Li
Keyword(s):  
Fractional Order ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Controller Design ◽  
Open Loop ◽  
System Stability ◽  
Synchronization Control ◽  
Motion Platform ◽  
Oscillation System ◽  
Filtering Method

H-type motion platform with linear motors is widely used in two-degrees-of-freedom motion systems, and one-direction dual motors need to be precisely controlled with strict synchronization for high precision performance. In this paper, a synchronous control method based on model decoupling is proposed. The dynamic model of an H-type air floating motion platform is established and one direction control using two motors with position dependency coupling is decoupled and converted into independent position and rotation controls, separately. For the low damping second-order oscillation system of the rotation control loop, a new fractional order biquad filtering method is proposed to generate an antiresonance peak to improve the phase and control gain of the open loop system, which can ensure system stability and quick attenuation for external disturbances. In the multiple-degree-of-freedom decoupled control loops, a systematic feedback controller design methodology is proposed to satisfy the given frequency domain design specifications; a feed-forward control strategy is also applied to compensate the disturbance torque caused by the platform motion. The simulation and experimental results demonstrate that the proposed synchronization control method is effective, and achieves better disturbance rejection performance than the existing optimal cancellation filtering method and biquad filtering method.

A near-optimal decentralized control approach for polynomial nonlinear interconnected systems

2020 ◽  
pp. 014233122097743
Author(s):  
Mohamed Sadok Attia ◽  
Mohamed Karim Bouafoura ◽  
Naceur Benhadj Braiek
Keyword(s):  
Optimal Control ◽  
Closed Loop ◽  
Sufficient Conditions ◽  
Open Loop ◽  
System Stability ◽  
Gronwall Lemma ◽  
Interconnected System ◽  
Control Approach ◽  
State Dependent ◽  
And Control

This article tackles the decentralized near-optimal control problem for the class of nonlinear polynomial interconnected system based on a shifted Legendre polynomials direct approach. The proposed method converts the interconnected optimal control problems into a nonlinear programming one with multiple constraints. In light of the formulated NLP optimization, state and control coefficients are used to design a nonlinear decentralized state feedback controller. Overall closed-loop system stability sufficient conditions are investigated with the help of Grönwall lemma. The triple inverted pendulum case is considered for simulation. Satisfactory results are obtained in both open-loop and closed-loop schemes with comparison to collocation and state-dependent Riccati equation techniques.

scholarly journals Iterative LQG Controller Design Through Closed-Loop Identification

1996 ◽  
Vol 118 (2) ◽  
pp. 366-372 ◽  
Author(s):  
Min-Hung Hsiao ◽  
Jen-Kuang Huang ◽  
David E. Cox
Keyword(s):  
Kalman Filter ◽  
State Feedback ◽  
Closed Loop ◽  
Controller Design ◽  
Open Loop ◽  
The State ◽  
Magnetic Suspension ◽  
Loop Model ◽  
Closed Loop Identification ◽  
Noise Statistics

This paper presents an iterative LQG controller design approach for a linear stochastic system with an uncertain openloop model and unknown noise statistics. This approach consists of closed-loop identification and controller redesign cycles. In each cycle, the closed-loop identification method is used to identify an open-loop model and a steady-state Kalman filter gain from closed-loop input/output test data obtained by using a feedback LQG controller designed from the previous cycle. Then the identified open-loop model is used to redesign the state feedback. The state feedback and the identified Kalman filter gain are used to form an updated LQG controller for the next cycle. This iterative process continues until the updated controller converges. The proposed controller design is demonstrated by numerical simulations and experiments on a highly unstable large-gap magnetic suspension system.

scholarly journals Multiloop and Prediction Based Controller Design for Sugarcane Crushing Mill Process

2015 ◽  
Vol 4 (4) ◽  
pp. 135
Author(s):  
Sandeep Kumar Sunori ◽  
Pradeep Kumar Juneja ◽  
Anamika Bhatia Jain
Keyword(s):  
Control System ◽  
Linear Model ◽  
Predictive Control ◽  
Closed Loop ◽  
Controller Design ◽  
Mimo System ◽  
Pi Controller ◽  
Open Loop ◽  
Turbine Speed ◽  
Mill Process

In the present work a sugarcane crushing mill is presented as a MIMO system with high multivariable interaction.A linear model of the plant is taken with flap position and turbine speed as manipulated variables and mill torque and buffer chute height as controlled variables.The multiloop PI controller has been designed for this plant by first investigating the RGA and the value of Niederlinski index of this plant.The decoupling of this system is done and the respective open loop and closed loop step responses are observed and compared with those of the composite MIMO system. Also the performance of multiloop controller is compared with controller designed using model predictive control system strategy for this plant.

Path Following Control of a Mobile Robot Using Contractive Model Predictive Control

2013 ◽  
Vol 397-400 ◽  
pp. 1366-1372
Author(s):  
Kiattisin Kanjanawanishkul
Keyword(s):  
Model Predictive Control ◽  
Mobile Robot ◽  
Predictive Control ◽  
Path Following ◽  
Open Loop ◽  
System Stability ◽  
Bounded Control ◽  
Loop Control ◽  
Guarantee System ◽  
The Stability

In this paper, we propose a novel controller based on contractive model predictive control for the path following problem of a mobile robot. Besides dealing with path following, we also fulfill the following objectives: bounded control signals and optimal forward velocity. These three objectives are all achieved through integrating into our model predictive control framework as constraints. However, the major concern in the use of model predictive control is whether such an open-loop control scheme can guarantee system stability. In this case, we apply the idea of a contractive constraint to guarantee the stability of our MPC framework. To illustrate its effectiveness, several simulation scenarios have been conducted.

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