Halkis Institute of Technology

Greece

Halkis Institute of Technology

Greece
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Economakos C.,Halkis Institute of Technology | Economakos G.,National and Kapodistrian University of Athens | Koutras I.,National and Kapodistrian University of Athens
IEEE International Symposium on Industrial Electronics | Year: 2010

Although the performance of traditional PLC technology is adequate for the majority of industrial automation and control tasks, there exist a number of demanding applications, which need more powerful alternatives. One such alternative, which has received considerable research interest in recent years, is the implementation of control algorithms on FPGAs. An inherent difficulty of this approach is that it requires expertise in both industrial automation and FPGAs. Also, FPGAs have been traditionally suited towards fast, fixed point calculations. This paper presents an automated methodology which addresses the first problem, by using language translators and hardware behavioral or high-level synthesis. For the second problem, different approaches to support floating point operations at the behavioral domain are thoroughly investigated. Overall, an efficient methodology for design space exploration of industrial control applications is proposed, using FPGA technology. The presented experiments show that design trade-offs can be easily explored and the desired solution for each application can be efficiently selected. © 2010 IEEE.


Koumboulis F.N.,Halkis Institute of Technology
IEEE International Conference on Emerging Technologies and Factory Automation, ETFA | Year: 2012

Time delay system descriptions are usually met in mechanical systems and industrial processes. Here, the general class of linear singular neutral multi delay systems is introduced. The controller is of the general proportional multi delay state feedback type. For the case of regularizable linear singular neutral multi delay systems the design problem of disturbance decoupling (DD) is solved under the constraint that the closed loop system must be left invertible. The necessary and sufficient conditions for the problem to admit a realizable solution are established and the general solution of the realizable controllers is derived. © 2012 IEEE.


Koumboulis F.N.,Halkis Institute of Technology | Kouvakas N.D.,Halkis Institute of Technology
2011 19th Mediterranean Conference on Control and Automation, MED 2011 | Year: 2011

The problem of Disturbance Rejection (DR) for MIMO general neutral multi-delay systems, is studied for the case of left invertible systems with measurable disturbances. The controller used is of the dynamic type involving delays and feeding back the measurable disturbances and the plant measurement outputs. The controller is assumed to be realizable. For this system case and controller type the necessary and sufficient conditions for the problem to have a solution are established and the general analytical expression of the controller matrices solving the problem is derived. © 2011 IEEE.


Koumboulis F.N.,Halkis Institute of Technology | Kouvakas N.D.,Halkis Institute of Technology
2011 19th Mediterranean Conference on Control and Automation, MED 2011 | Year: 2011

For a quarter car model, a PID controller that provides ride comfort is developed. The PID controller parameters are derived using a metaheuristic algorithm. The performance of the proposed control scheme and its robustness with respect to uncertainties of the model parameters are examined through computational experiments. The proposed control scheme has satisfactory performance and feeds back only one measurable variable thus providing a simple and cheap solution. © 2011 IEEE.


Kouvakas N.D.,Halkis Institute of Technology | Koumboulis F.N.,Halkis Institute of Technology
2011 19th Mediterranean Conference on Control and Automation, MED 2011 | Year: 2011

The issue of developing a robust control scheme for permanent magnet synchronous motors is investigated. Towards this aim a two stage control scheme is proposed. The inner loop controller is a robust controller of the feedback linearization type with degrees of freedom satisfying I/O decoupling and pole assignment for the motor's currents. The outer loop controller is a PI controller regulating the angular velocity of the rotor. The conditions for the stability of the overall closed loop system are derived in the form of analytical inequalities covering also the issue of robustness of the closed loop system. The internal and external controllers' degrees of freedom are determined metaheuristically, through computational experiments. © 2011 IEEE.


Koumboulis F.N.,Halkis Institute of Technology | Kouvakas N.D.,Halkis Institute of Technology
IEEE International Conference on Emerging Technologies and Factory Automation, ETFA | Year: 2013

The problem of triangular decoupling with simultaneous disturbance rejection (TDDR) is studied for general neutral multi delay systems via a realizable dynamic multi delay controller feeding back measurable disturbances and the plant measurement outputs. The necessary and sufficient conditions for the problem to have a solution are established and the general analytical expression of the realizable multi delay dynamic controllers solving the problem is derived. The results are successfully applied to control an activated sludge process with varying dissolved oxygen concentration at the influent. © 2013 IEEE.


Skarpetis M.G.,Halkis Institute of Technology | Koumboulis F.N.,Halkis Institute of Technology
IEEE International Conference on Emerging Technologies and Factory Automation, ETFA | Year: 2013

A robust control scheme for an electro hydraulic actuator is presented. A PID (Proportional - Integral - Derivative) controller is designed for controlling the position of the actuator in a wide range of physical uncertainties and external disturbances. The performance of the actuator variables is illustrated via simulations. In the future the present results will be applied to a real experimental system involving a double acting cylinder (Festo - model), with an electro hydraulic servo valve or an ON - OFF hydraulic valve where the PID controller will be realized in MATLAB environment with a Q4 Quanser card. © 2013 IEEE.


Koumboulis F.N.,Halkis Institute of Technology
IEEE International Conference on Emerging Technologies and Factory Automation, ETFA | Year: 2013

The general class of linear singular neutral multi delay systems is introduced. The controller is of the general proportional multi delay measurement output feedback type. For the case of regularizable linear singular multi delay systems the design problem of Exact Model Matching (EMM) is solved under the assumption that the ideal model is left invertible. The necessary and sufficient conditions for the problem to admit a realizable controller solution are established and the general solution of the realizable controllers is derived. © 2013 IEEE.


Skarpetis M.G.,Halkis Institute of Technology | Koumboulis F.N.,Halkis Institute of Technology | Ntellis A.S.,Halkis Institute of Technology
2013 21st Mediterranean Conference on Control and Automation, MED 2013 - Conference Proceedings | Year: 2013

The position control problem of an electro pneumatic clutch actuator is formulated as a robust asymptotic tracking control problem. To solve the problem the Internal Model Principle is appropriately modified to a Hurwitz invariability problem solved through a constructive robust stability algorithm which is numerically integrated via a Simulated Annealing Algorithm. The problem is proven to be always solvable and the controller parameters providing a suboptimal solution are computed. Simulation results for the nonlinear model of the actuator and for all the expected range of model and load uncertainties illustrate the satisfactory control. © 2013 IEEE.


Koumboulis F.N.,Halkis Institute of Technology | Tzamtzi M.P.,Halkis Institute of Technology | Economakos C.E.,Halkis Institute of Technology
International Journal of Modelling, Identification and Control | Year: 2011

In this paper, we present the application of multivariable step-wise safe switching (MSWSS) in order to control a constant turning force system under varying cutting conditions. The non-linear part of the plant's model is considered to be unknown and it is approximated by a set of linearised models which are derived through identification around corresponding operating points. State feedback proportional-integral controllers are designed to achieve sufficiently fast settling time and keep the cutting force at the appropriate level as the cutting depth varies with time. The controllers are designed using a metaheuristic search algorithm so as to achieve the required performance simultaneously for two adjacent operating points. A state observer is used to estimate the acceleration of the servomechanism that determines the feed rate of the cutting machine. Closed-loop performance is illustrated through simulation results. Copyright © 2011 Inderscience Enterprises Ltd.

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