New Observer-Based Controller Design for Delayed Systems Subject to Input Saturation and Disturbances

2019 ◽  
Vol 44 (3) ◽  
pp. 1081-1092 ◽  
Author(s):  
Nabil El Fezazi ◽  
Ouarda Lamrabet ◽  
Fatima El Haoussi ◽  
El Houssaine Tissir
Keyword(s):  
Controller Design ◽  
Input Saturation ◽  
Delayed Systems

Robust model predictive control synthesis for state-delayed systems with randomly occurring input saturation nonlinearities

2016 ◽  
Vol 40 (1) ◽  
pp. 179-190 ◽  
Author(s):  
Langwen Zhang ◽  
Wei Xie ◽  
Zhaozhun Zhong ◽  
Jingcheng Wang
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
State Feedback ◽  
Controller Design ◽  
Input Saturation ◽  
Time Instant ◽  
Control Synthesis ◽  
Linear Matrix ◽  
Model Parameters ◽  
Delayed Systems

In this paper, a model predictive control algorithm is presented for linear parameter varying systems with both state delays and randomly occurring input saturation. The input saturation is assumed to be occurred randomly with Bernoulli-distributed white sequences. A constant sate feedback law is designed at each time instant to ensure the robust stability of the closed-loop system with respect to polytopic uncertainties. The optimization of model predictive controller is cast into solving a linear matrix inequalities optimization problem. Then, the results are extended to gain-scheduled approach in which a set of state feedback laws are designed for each vertex of the system model. The state feedback law is scheduled by the time varying model parameters to achieve less conservatism in controller design. Finally, two examples are employed to show the effectiveness of the proposed algorithms.

Enhanced Composite Nonlinear Control Technique using Adaptive Control for Nonlinear Delayed Systems

2020 ◽  
Vol 13 (3) ◽  
pp. 396-404
Author(s):  
Sonal Singh ◽  
Shubhi Purwar
Keyword(s):  
Adaptive Control ◽  
Actuator Saturation ◽  
Input Saturation ◽  
Chemical Reactor ◽  
Control Technique ◽  
Control Law ◽  
Nonlinear Feedback ◽  
Composite Nonlinear Feedback ◽  
Delayed Systems ◽  
Analysis Of Stability

Background and Introduction: The proposed control law is designed to provide fast reference tracking with minimal overshoot and to minimize the effect of unknown nonlinearities and external disturbances. Methods: In this work, an enhanced composite nonlinear feedback technique using adaptive control is developed for a nonlinear delayed system subjected to input saturation and exogenous disturbances. It ensures that the plant response is not affected by adverse effect of actuator saturation, unknown time delay and unknown nonlinearities/ disturbances. The analysis of stability is done by Lyapunov-Krasovskii functional that guarantees asymptotical stability. Results: The proposed control law is validated by its implementation on exothermic chemical reactor. MATLAB figures are provided to compare the results. Conclusion: The simulation results of the proposed controller are compared with the conventional composite nonlinear feedback control which illustrates the efficiency of the proposed controller.

Regional stabilization and H∞ congestion control with input saturation

2021 ◽  
pp. 014233122199273
Author(s):  
Sadek Belamfedel Alaoui ◽  
El Houssaine Tissir ◽  
Noreddine Chaibi ◽  
Fatima El Haoussi
Keyword(s):  
Linear Systems ◽  
Controller Design ◽  
Input Saturation ◽  
Domain Of Attraction ◽  
Queue Management ◽  
Variable Delay ◽  
Challenging Problem ◽  
Regional Stabilization ◽  
Small Gain ◽  
Improved Performance

Designing robust active queue management subjected to network imperfections is a challenging problem. Motivated by this topic, we addressed the problem of controller design for linear systems with variable delay and unsymmetrical constraints by the scaled small gain theorem. We designed two mechanisms: robust enhanced proportional derivative; and robust enhanced proportional derivative subjected to input saturation. Discussion of their practical implementations along with extensive comparisons by MATLAB and NS3 illustrate the improved performance and the enlargement of the domain of attraction regarding some literature results.

A New Approach to Delay-Dependent H∞ Control of Linear State-Delayed Systems

2004 ◽  
Vol 126 (1) ◽  
pp. 201-205 ◽  
Author(s):  
De-Jin Wang
Keyword(s):  
Controller Design ◽  
Linear Matrix ◽  
State Delay ◽  
Delayed Systems ◽  
Cross Term ◽  
Closed Loop Systems ◽  
Linear State ◽  
Delay Dependent ◽  
Time Invariant ◽  
Control Criterion

An alternative delay-dependent H∞ controller design is proposed for linear, continuous, time-invariant systems with unknown state delay. The resulting delay-dependent H∞ control criterion is obtained in terms of Park’s inequality for bounding cross term. The H∞ controller determined by a convex optimization algorithm with linear matrix inequality (LMI) constraints, guarantees the asymptotic stability of the closed-loop systems and reduces the effect of the disturbance input on the controlled output to within a prescribed level. A numerical example illustrates the effectiveness of our method.

Robust stabilization of longitudinal tracking for cooperative adaptive cruise control considering input saturation

2020 ◽  
Vol 34 (35) ◽  
pp. 2050409
Author(s):  
Youguo He ◽  
Xiaoxiao Tian ◽  
Jie Shen ◽  
Chaochun Yuan ◽  
Yingkui Du
Keyword(s):  
Adaptive Cruise Control ◽  
Control Method ◽  
Controller Design ◽  
Actuator Saturation ◽  
Kinematic Model ◽  
Input Saturation ◽  
Robust Stabilization ◽  
State Feedback Control ◽  
Cruise Control ◽  
Cooperative Adaptive Cruise Control

This paper is concerned with the problem of constraint control for cooperative adaptive cruise control (CACC) with input saturation and input-additive uncertainties. An integrated longitudinal kinematic model of CACC system including vehicle model and constant time headway is established taking into account input saturation and input-additive uncertainties. According to the system’s robustness requirements under input saturation, the saturation control method is introduced. In order to achieve robust global stabilization of the system, a low-gain state feedback control law is designed by using linear low-gain feedback and gain scheduling. Meanwhile, in order to avoid the saturation of the control system, the low gain parameter [Formula: see text] is introduced into the controller design. Finally, the simulation of homogeneous and heterogeneous platoons is carried out by MATLAB/Simulink, which verifies the feasibility and effectiveness of the designed controller. Compared with the SMC controller, saturation controller successfully suppresses the acceleration amplification in the process of propagation along the vehicle platoon, avoids actuator saturation and realizes the stability of CACC system.

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