A model-free control method for big time delay system based on improved iterative feedback tuning

Flatness control system is characterized by multi-parameters, strong coupling, pure time delay, which complicate the establishment of an accurate mathematical model. Therefore, a control scheme that combines dynamic decoupling, PI (Proportion and Integral) control and adaptive Smith predictive compensation is proposed. To this end, a dynamic matrix is used to decouple the control system. A multivariable coupled pure time-delay system is transformed into several independent generalized single-loop pure time-delay systems. Then, a PI-adaptive Smith predictive controller is constructed for the decoupled generalized single-loop pure time-delay system. Simulations show that the scheme has a simple and feasible structure, and good control performance. When the mathematical model of the control system is inaccurate, the control performance of adaptive Smith control method is evidently better than that of the ordinary Smith control method. The model is successfully applied to the cold rolling production site through LabVIEW, and the control accuracy is within 5I. This study reveals a new solution to the problem of coupled pure time-delay in flatness control system.

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A Time-Delay Prediction Control Method Based on Immune Optimization

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.317-319.1250 ◽

2011 ◽

Vol 317-319 ◽

pp. 1250-1254

Author(s):

Xue Song Xu ◽

Xing Bao Liu

Keyword(s):

Time Delay ◽

Predictive Control ◽

Control Method ◽

Clonal Selection ◽

Delay System ◽

Time Delay System ◽

Immune Optimization ◽

Process System ◽

Prediction Control ◽

Delay Prediction

A time-delay predictive control algorithm based on immune computational intelligences is proposed in this paper. The predictive control parameter was optimized through immune clonal selection. Which avoids calculate Diophantine equation and inverse matrix, reduces the input dimensions of the nonlinear map. Simulations were conducted on the time-delay system, non-minimum phase of the process system, divergent system illustrate that this approach is a feasibility and effectiveness way and demonstrate its rapid responds, small overshoot and high adaptability for time delay system.

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Smith Prediction Based on Genetic Algorithm Self-Tuning PID Control

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.602-605.1186 ◽

2014 ◽

Vol 602-605 ◽

pp. 1186-1189

Author(s):

Dong Sheng Wu ◽

Qing Yang

Keyword(s):

Genetic Algorithm ◽

Time Delay ◽

Pid Control ◽

Pid Controller ◽

Control Method ◽

Delay System ◽

Time Delay System ◽

Self Tuning ◽

On Line ◽

Turning Control

Aiming at the phenomena of big time delay are normally existing in industry control, this paper proposes an intelligent GA-Smith-PID control method based on genetic algorithm and Smith predictive compensation algorithm and traditional PID controller. This method uses the ability of on line-study, a self-turning control strategy of GA, and better control of Smith predictive compensation to deal with the big time delay. This method overcomes the limitation of traditional PID control effectively, and improves the system’s robustness and self-adaptability, and gets satisfactory control to deal with the big time delay system.

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The control method of a time-delay system with nonlinear uncertainty

2010 International Conference on Computer Application and System Modeling (ICCASM 2010) ◽

10.1109/iccasm.2010.5619160 ◽

2010 ◽

Cited By ~ 1

Author(s):

Yandong Zhao ◽

Xinglong Zhang ◽

Xianyong Ren

Keyword(s):

Time Delay ◽

Control Method ◽

Delay System ◽

Time Delay System

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Fractional-Order Controller Design for Oscillatory Fractional Time-Delay Systems Based on the Numerical Inverse Laplace Transform Algorithms

Mathematical Problems in Engineering ◽

10.1155/2015/917382 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10

Author(s):

Lu Liu ◽

Feng Pan ◽

Dingyu Xue

Keyword(s):

Time Delay ◽

Laplace Transform ◽

Fractional Order ◽

Control Method ◽

Delay System ◽

Inverse Laplace Transform ◽

Delay Systems ◽

Time Delay System ◽

Numerical Inverse Laplace Transform ◽

Fractional Order Controller

Fractional-order time-delay system is thought to be a kind of oscillatory complex system which could not be controlled efficaciously so far because it does not have an analytical solution when using inverse Laplace transform. In this paper, a type of fractional-order controller based on numerical inverse Laplace transform algorithm INVLAP was proposed for the mentioned systems by searching for the optimal controller parameters with the objective function of ITAE index due to the verified nature that fractional-order controllers were the best means of controlling fractional-order systems. Simulations of step unit tracking and load-disturbance responses of the proposed fractional-order optimalPIλDμcontroller (FOPID) and corresponding conventional optimal PID (OPID) controller have been done on three typical kinds of fractional time-delay system with different ratio between time delay (L) and time constant (T) and a complex high-order fractional time delay system to verify the availability of the presented control method.

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Model-free Control of Manipulator in Task Space Containing Mismatched Uncertainty

10.21203/rs.3.rs-685614/v1 ◽

2021 ◽

Author(s):

Xiaohui Yang ◽

Zhenghong Xu ◽

Wenjie Zhang ◽

Wei Zhang ◽

Peter Xiaoping Liu

Keyword(s):

Time Delay ◽

Control Method ◽

Time Delay Estimation ◽

Delay Estimation ◽

Task Space ◽

Estimation Errors ◽

Trajectory Tracking Control ◽

Model Free ◽

Model Free Control ◽

Mismatched Uncertainty

Abstract In this paper, a novel trajectory tracking control method for manipulator task space containing mismatched uncertainty is proposed. This paper considers the mismatched uncertainty that exists in the signal conversion between joint space and task space in the robotic arm system. The time delay estimation is employed to approximate the dynamic and kinematic parameters of the system to achieve model-free control. The time delay estimation errors is treated as part of the system disturbances and a disturbance observer based on an auxiliary control system capable of estimating both matched and mismatched disturbances is designed, which does not require additional design of adaptive laws to compensate for disturbances or upper bounds on the derivatives of disturbances. We transform the control error by a prescribed performance function to accomplish transient control of the error, and design a fast terminal sliding surface for the virtual control variables based on the backstepping design method to improve the convergence speed of the controller. Based on the Lyapunov criterion, the closedloop stability of the whole system is demonstrated. The feasibility and superiority of the method in this paper is demonstrated by numerical simulation compared with other control methods.

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Research of Nonlinear PID Control Method for Time Delay Systems

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.44-47.3839 ◽

2010 ◽

Vol 44-47 ◽

pp. 3839-3843

Author(s):

Wen Bo Liu ◽

Meng Xiao Wang

Keyword(s):

Time Delay ◽

Pid Control ◽

Control Method ◽

Delay System ◽

Smith Predictor ◽

Delay Systems ◽

Time Delay Systems ◽

Nonlinear Controller ◽

Time Delay System ◽

Nonlinear Pid Control

A nonlinear PID control method based on Smith predictor is presented in this paper to control the time delay systems. This method combines the Smith predictor with nonlinear controller. And the simulation study had been done for a first-order time-delay system. The results show that this method offer good static and dynamic characteristics, at the same time its disturbance-rejection and robustness are better.

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