Showing papers by "Antonios Armaou published in 2018"

Study on ADRC Parameter Optimization Using CPSO for Clamping Force Control System

Abstract: Clamping force control system is essential for clamping tasks that require high precision. In this paper, Active Disturbance Rejection Controller (ADRC) is applied for clamping force control system, aiming to achieve higher control precision. Furthermore, the CPSO-ADRC system is proposed and implemented by optimizing the critical parameters of ordinary ADRC using chaos particle swarm optimization (CPSO) algorithm. To verify the effectiveness of CPSO-ADRC, Particle Swarm Optimization- (PSO-) ADRC is introduced as a comparison. The simulation results show that the CPSO-ADRC can effectively improve the control quality with faster dynamic response and better command tracking performance compared to ordinary ADRC and PSO-ADRC.

Efficient reduced order controller design for dissipative PDE systems with strong convective phenomena

Abstract: The control of dissipative distributed parameter systems with strong convective phenomena is considered, employing model order reduction. The accuracy of the derived reduced order model (ROM) and the associated observer may decrease as the system behavior switches from diffusion-dominant to convection-dominant. To mitigate the issue, we propose to use adaptive proper orthogonal decomposition (APOD) to capture the changing behavior of the system. A Lyapunov controller is designed based on the ROM to control the system in the presence of disturbance and strong convective phenomena. Galerkin method is used to construct the ROM. The basis functions needed in Galerkin method are updated using APOD. A case study of regulating a tubular reactor at an open-loop unstable steady state is presented, where the performance of the ROM-based observer is evaluated. It's also demonstrated that APOD can improve the accuracy of the observer when an unexpected disturbance occurs.

Dissipative distributed parameter systems on-line reduction and control using DEIM/APOD combination

Abstract: The output feedback control of distributed parameter systems based on adaptive model reduction is explored in this paper. A significant computational hurdle when using model reduction for control (MRC) is the numerical computation of integrals that appear in the reduced order model limiting MRC's applicability when dealing with nonlinearities. The objective of this paper is to further reduce the computational cost in adaptive proper orthogonal decomposition (APOD). It is addressed by using discrete empirical interpolation method (DEIM) in the observer and controller to reduce the computational cost associated with the nonlinear functions. The proposed method is successfully illustrated on a diffusion reaction process and a fluid flow system described by the Kuramoto-Sivashinsky equation.

Investigation of CO2 sorption mechanisms in isothermal columns via transient material and energy balance PDE models.

Abstract: The behavior of an isothermal packed bed sorption column for CO2 is investigated based on combined mass spectrometry and calorimetry temporal measurements at different temperatures. The inclusion of the calorimetry data stream at multiple temperatures accentuates the limitations of our previous spatiotemporal model with a simple sorption mechanism to describe the experimental observations. We propose four models, which consider dispersion and convection with different descriptions of the sorption mechanism. The unknown parameters in the models are determined by minimizing the integral in time of the squared difference between model prediction and the experimental measurements. Analyzing the simulation results for thermodynamic consistency and site density, we conclude physical sorption followed by chemical sorption is a probable mechanism to describe the specific experiment data. We also conclude a combination of multiple measurement streams is required to verify the consistency of proposed mechanisms and...