Increasing complexities in industrial processes have compelled the control engineers to implement advanced control strategies to improve the efficiency of the process control system. Usage of PID controllers has become indispensible for its simplicity, reliability and flexibility [1]. The proportional term in the controller generally helps in establishing system stability and improving the transient response while the derivative term is often used when it is necessary to improve the closed loop response speed even further. Conceptually, the effect of the derivative term is to feed information on the rate of change of the measured variable into the controller action. The most important term in the controller is the integrator term that introduces a pole at s = 0 in the forward loop of the process [5]. This makes the compensated open loop system a type 1 system for perfect steady state set point tracking. Technically, a PID controller reduces the steady state error, minimizes the overshoot and improves the settling rate [6]. They do, however, present some challenges to control and instrumentation engineers in the aspect of tuning of the gains required for stability and good transient performance [5]. These features can be attained only by proper tuning of the PID controller. Various tuning algorithms were proposed by many scientists- each algorithm having its own merits and demerits. PID controller is tuned using the algorithm which is suitable for that particular process. Well known and widely implemented algorithms include ZN tuning, Cohen-Coon method, Tyreus Luyben technique and Internal model controller.
ZN method was proposed by John G. Ziegler and Nathaniel B. Nichols in 1942 [5]. ZN method is one of the most widely used...
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... Tuning using Differential Evolution and Genetic Algorithm, in International Journal of Innovative computing, Information and control, November 2012 .
[3]. Neenu Thomas, Dr. P. Poongodi, Position Control of DC Motor Using Genetic Algorithm Based PID Controller, in the Proceedings of the World Congress on Engineering 2009 Vol II.
[4]. Book named Control and dynamical systems by Richard M. Murray, Chapter 6 named Transfer Function.
[5]. Arturo Y. Jaen-Cuellar, Rene de J. Romero-Troncoso, Luis Morales-Vela Zquez and Roque A. Osornio-Rios, PID controller tuning optimization with Genetic Algorithm in Servo system, in International Journal of Advanced Robotic Systems, May 2013.
[6]. Aytekin B. Agis, Determination of the PID Controller Parameters by Modified Genetic Algorithm for Improved Performance, in the Journal of Information , Science and Engineering, 2007.
Tadić, A., Wagner, S., Hoch, J., Başkaya, Ö., von Cube, R., Skaletz, C., ... & Dahmen, N. (2009).
The tuning strategy process parameters are designed such that they do not effect 1) the maximum throughput of multi-core processors and 2) the overall execution time of workloads. There have been experiments
A maglev system is nonlinear and its open-loop response is unstable because of the nature of the magnetic forces used. PI controllers are based on a linearized model, so they do not compensate for certain variations. These variations can occur when a magnetic bearing experiences a working load change on the rotor during operation, ...
The PSS is an additional control system, which is often applied as a part of an excitation control system. The basic function of the PSS is to apply a signal to the excitation system, producing electrical torques to the rotor in phase with speed differences that damp out power oscillations. They perform within the generator’s excitation system to create a part of electrical torque, called damping torque, proportional to speed change. A CPSS can be modeled by a two stage (identical), lead-lag network which is represented by a gain K and two time constants T1 and T2. This network is connected with a washout circuit of a time constant Tw. The signal washout block acts as a high-pass filter with the time constant Tw that allows the signal associated with the oscillations in rotor speed to pass unchanged. Furthermore, it does not allow the steady state changes to modify the terminal voltages. The phase compensation blocks with time constants T1i – T4i supply the suitable phase-lead characteristics to compensate the phase lag between the input and the output signals. The commonly used structure of the PSS is shown in Fig
Genetic Algorithms provide a holistic search process based on principles of natural genetics and survivals of the fittest……
Based on the evolutionary theory as described above, evolutionary computation produce solutions and keeping the fittest of them. In 1948, Alan Turing was the first who introduce this biological approach in problem solving. On 1962, we had the first actual experiments on "optimization through evolution and recombination".
...ter-3 gives the overall about genetic algorithms. An introduction of algorithm is given and how and why they work is explained with help of examples. Different procedures are explained that are used in genetic algorithms
Julie, A., Sokol & Robert, J. Thomas (2004) State of the art, viewed 27 March 2008,
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Tamborini, Ron ; Eastin, Matthew S. ; Skalski, Paul ; Lachlan, Kenneth ; Fediuk, Thomas A. ;
The output power of a motor could be calculated by using this formula, P = Torque.w where w the angular velocity[7]. Knowing and computing all those parameters of the motor which are torque, angular velocity and output power will help to know the proper motor that could be used for specific applications and control the operation of that motor.
Dc servo motor is widely used for industrial and domestic purpose. it is necessary to establish the mathematical model of DC servo motor here we are using armature control DC motor to control speed and position of Dc motor. In armature control of DC motor the resistance Ra and inductance La connected in series and voltage is representing the back emf of DC servo motor. The motor parameter and variable define as follow. Consider armature control dc motor shown in fig
Linear programming helps the Mini factory in optimum operation of numerous standing factors in production, w...
The equations of motion form the basic building blocks for any system under consideration. These equations should be formulated as accurately as possible to model the desired system. The δinaccuracies in formulating these equations could result in faulty behaviour of the system which could be very difficult to understand. However, modern control systems are designed to accommodate model inaccuracies to a certain degree. It is very important to ensure that our model is modelled within this range. Errors could also enter the system during the calculation stage due to the precision and number of digits used to represent the values.
Manufacturing the process design also faces the same challenge in the optimization of the product (ARAUJO, JOSÉ AUGUSTO DA ROCHA DE; Costa, Reinaldo Pacheco da, 2004, p. 4).