Current issue of "International Review of Automatic Control (IREACO)"

by H. E. A. Ibrahim, Ahmed A. Hakim Mahmoud

Abstract - This paper presents analysis for two different types of controllers for speed control of separately excited DC motor. Improved Ant colony algorithm has been analyzed and presented as an adapted optimization algorithm for tuning PID controller parameters. Conventional PID has been applied for the same machine. Comparison between the two controllers is provided based on step response parameters like maximum overshoot, rise time and settling time.

Keywords: DC Motor, PID Tuning, Ant Colony Algorithm (ACO).

by S.Vijaya, A. Senthil Kumar, R.Suganya

Abstract - The operation of permanent magnet (PM) stepper motor in microstepping mode requires precise rotor position tracking. The position of the rotor provides information on angular rotation and speed. This is used to estimate the step positional error, positional accuracy, current ripple and power loss at different switching frequencies. Numerous techniques have been developed to track the rotor position and determine the positional error to improve the dynamic performance of the stepper motor. The literature review begins by investigating the assumptions in the development of the mathematical model of the PM stepper motor. The need for microstepping control of the PM stepper motor is presented. The explanation regarding the operation of the PM stepper motor in open loop with microstepping control using current feedback and closed loop with current and/or position feedback are conversed. In addition, the review is extended to the use of observers for estimating the rotor position in closed loop. A detailed examination on the diverse approaches for improving the performance of the PM stepper motor using microstepping control is provided.

Keywords: Instability, Microstepping, PM Stepper Motor, Position Tracking, Steady-State Position Error.

by N. N. Praboo, P. K. Bhaba

Abstract - This work focuses on real time implementation of third generation CRONE control strategy for the speed control of DC motor. The dynamic second order transfer function model is analytically derived for the speed control system based on real time data. An attempt has been made to compare third generation CRONE controller with Fractional order (FO) PIλ controller. The real time run of both the controller results are recorded and reported in time domain and integral time performance indices. The real time result shows that the third generation CRONE controller may be more effective and gives superior performance over the FO PIλ controller.

Keywords: CRONE, DC Motor, Fractional Order Controller, Nichols Loci, Stability Boundary Locus.

by M. Benasla, T. Allaoui, M. Brahami

Abstract - Recovery from DC fault represents an important aspect of HVDC (High Voltage Direct Current) operation. The recovery time depends on the characteristics of the DC and AC systems and the control strategy used to clear the fault. The main characteristic of a temporary HVDC line fault is that once started, it will not be extinguished by itself until the current is brought down to zero and the arc deionised. Thus, there has to be some control function that brings the current down to zero when a fault occurs on a DC line. If DC control and protection system modules fail, system safety will be threatened heavily. The most control function used to extinguish the DC fault is achieved by retarding the rectifier firing angle into the inverter operating region to quickly absorb all energy from the dc line and deionize the fault. This paper presents a detailed analysis and simulation of HVDC line protection under the single pole to ground fault of CIGRE HVDC benchmark model. Furthermore, this paper presents a control strategy for HVDC to extinguish the DC fault current. This strategy attempts to improve the recovery performance of power to minimize the energy loss and prevent transient instability of the AC system. Simulation study on MATLAB.SimPowerSystems is carried out to validate the concept.

Keywords: HVDC, DC Line Fault, DC Line Protection, VDCL.

by Adel Taeib, Abdelkader Chaari

Abstract - The adaptive particle swarm optimization based proportional-integral-derivative (APSO-PID) controller is proposed to control for Takagi-Sugeno (T-S) fuzzy modelling. The APSO algorithm is applied to automatically tune the gains of PID controller. In the proposed method, an inertia weight of PSO is adaptively adjusted based on the swarm condition. The personal and the global best position of particles is taken and used to calculate the inertia weight during the searching process by using feedback mechanism. The practicality and effectiveness of the identification and control scheme is demonstrated by simulation results involving simulations of a continuous stirred-tank reactor.

Keywords: Takagi-Sugeno Fuzzy Model, PID Controller, Adaptive Particle Swarm Optimization.

by M. Selmi, H. Rehaoulia

Abstract - Recently, self excited induction generators (SEIG) are strongly present in wind energy conversion applications. This is due to its many advantages. This paper proposes an alternative method for the steady-state performance characteristics of a SEIG. Unlike the previous method, with this proposed one, extensive and hard effort can be avoided in the resolving of the characteristic equation. In this method, the model is formulated in a simple way and then solved using a numerical MATLAB function “fzero”. The effectiveness of this method has been confirmed by comparing on a 0.8- kW induction generator the computed results, of some performance, obtained by the proposed technique as the corresponding obtained with an experimental test.

Keywords: Induction Generator, Self-Excited Induction Generator (SEIG), Steady-State Analysis.

by Ján Cigánek, Filip Noge, Štefan Kozák

Abstract - The presented paper deals with an effective approach of the robust controller design based on the fuzzy logic. The proposed controller design is verified on the case study of the selected mechatronic system. All presented results are reached in co-simulation of two different modeling environments - Matlab-Simulink and MSC Adams. MSC Adams is used for the dynamics of the mechatronic system, Matlab-Simulink for the control part of the co-simulation expressed by the fuzzy controller, respectively.

Keywords: Control System, Co-Simulation, Fuzzy Controller, Fuzzy Logic, Matlab-Simulink, Mechatronic System, MSC Adams, Robotic Arm, Soft Computing.

by S. Sundeep, G. Madhusudhana Rao, B. V. Sankar Ram

Abstract - This research work investigates about the wind energy conversion system will receive the extensive attention among the various renewable energy systems. The extraction of the maximum possible power available wind energy is an important area of research among the speed sensorless MPPT control of wind area. This paper presents a power point tracking (MPPT) Technique for high performance wind turbine with induction machines based on expert systems (Artificial Neural Networks). In this paper, an ANN has been trained in off-line to learn about wind turbine characteristics of the torque with the wind speed and the speed of the machine which will be deployed in online for measuring the speed of the wind and torque. The reference speed of the machine is then calculated based on the control of the signal power feedback (PSF). Voltage oriented control of the machine is further integrated with an expert sensorless technique. The proposed method was simulated and conformed on the actual circuit in online.

Keywords: Wind Generation, MPPT, Voltage Control, Computer Simulation, Wind Energy Conversion Systems, Incremental Conductance.

by P. Senthilkumar, M. Balachandran, N. P. Subramaniam

Abstract - Space vector pulse width modulation (SVPWM) technique has become the most popular and important PWM techniques for three-phase voltage source inverters (VSI) fed control of induction, brushless dc, switched reluctance (SR) and permanent magnet synchronous motors. SVPWM is a method of pre-calculation of switching timing instants for various sections of target output which has options in terms of positioning vectors inside every sampling interval. Even though the basic structure for all SVPWM variants is same, there are more options in the arrangement of the voltage vectors in each sector. Competency of difference SVPWM variants can be understood through their analog equivalencies (reference). This paper presents eight different variations of SVPWM. A comparative evaluation of all these variants in terms of attributes such as switching loss factor (SLF), distortion factor (DF) and total harmonic distortion (THD) in output line voltage is reported. Simulation results are provided to illustrate the analysis.

Keywords: Sinusoidal Pulse Width Modulation (SPWM), Space Vector Pulse Width Modulation (SVPWM), Total Harmonic Distortion (THD), Switching Loss Factor (SLF).

by M. Litim, A. Omari

Abstract - This paper presents a sliding mode control of a flight simulator Gough-Stewart type. The control is based on the inverse dynamic model of the robot in task space. Kinematic analysis is also discussed. High performance tracking control of a 6 DOF Stewart platform normally requires full knowledge of the system dynamics. In this paper, some important properties of the dynamics of the Stewart platform are considered to develop a sliding mode controller which can drive the upper platform angular and translation positions to the desired trajectories. Stability analysis based on Lyapunov theory is performed to ensure that the designed controller is stable. Numerical simulation is completed to show the effectiveness of the control system even in the case of large parameter variations.

Keywords: Flight Simulator, Gough-Stewart Platform, Sliding Mode Control, Lyapunov Stability.

by Daniel Drăghici, Aurel Cireşan, Mircea Gurbină, Dan Lascu

Abstract - Predictive digital peak current control (PDPCC) in dc/dc converters using trailing triangle modulation (TTM) is analyzed in detail. The recurrence duty cycle relationship is derived and based on it stability analysis is carried out. It is proved instability is encountered on the whole range of the duty cycle and therefore peak current control using trailing triangle modulation, even proposed and mentioned in some publications, is unusable The analysis is performed in a general manner, in the sense it is converter topology independent. The theoretical considerations are confirmed for a boost converter, first based on state-space equations using the MATLAB program and finally by circuit simulation using the CASPOC package.

Keywords: Current Programmed Control, Trailing Triangle Modulation, Predictive Current Control, Peak Current Control.

by S. Benmansour Aboura, A. Omari, K. Zemalache Meguenni

Abstract - This paper discuses a new scheme for an optimal motion planning for golf swing robot using genetic algorithm with B-Spline Cubic Uniform approximation. This kind of manipulators has been recently developed in an attempt to simulate the high-speed swing motions of golfer. The problem is formulated as a constrained and multi-objectives optimization. The cost function is to minimizing the robot’s energy consummate and intermediate and final state errors. In order to validate the obtained trajectories, a computed torque controller combined with an optimal feedforward torque is applied to the robot. The global stability has been also proved using Lyapunov function. Simulation results show the effectiveness of the proposed schemes.

Keywords: Golf Swing Robot, Motion Planning, B-Spline, Genetic Algorithm, Optimization, Computed Torque Controller.

by A. Boutte, A. Midoun

Abstract - The conventional methods applied to identify the battery’s parameters consist in estimating the state of charge (SOC), based on an electrical or empirical models developed with fixed parameters, to establish an appropriate command to charge or to discharge the battery. These methods are adapted for uncritical basic system (cellular phone, battery of cars with an internal combustion) which the battery can be changed easily without any mission or cost impacts. Whoever the methods are inefficient in some fields like spacecraft, stand-alone photovoltaic system (PV), electric (EV) and hybrid Vehicle (HEV) which depends, totally or in majority, of the stored electric energy. Trying to increase the effectiveness, we use a new approach of identification that combined the conventional methods with adaptive and dynamic techniques. This approach is already used in other domains and proved their efficiency with a remarkable robustness. From the estimation methods, the Kalman filter (KF) is chosen because of its reputation as an optimal estimator in the field of tracking parameters. This work illustrates new approach to identify Lead Acid (LA) Battery parameters using KF estimator, followed by a simulation to validate the algorithms, also we use an experimental PV system developed in our laboratory to approve the results.

Keywords: Internal Parameters, Dynamic Modeling, Kalman Filter, Photovoltaic System.

by S. Nekrouf, M. Bouhamida, Z. Bellahcen

Abstract - This paper deals with robust control for a nonlinear multi-input multi-output system called the twin rotor MIMO system (TRMS). The mathematical modeling of helicopter model is simulated using MATLAB/Simulink for controlling the system in elevation and azimut angles using an H∞ robust control with a new method of optimization based on a genetic algorithm (GA) technique. The basic idea is to make handle by the genetic algorithm to optimize the weight functions. Obtained simulation results for different input signals are encouraging and the method is more effective than the standard techniques.

Keywords: Genetic Algorithm, H∞, Nonlinear Systems, Robust Control, System Coupled.

by I. Elaissi, O. Taouali, H. Messaoud

Abstract - This paper proposes a new online kernel identification method of a nonlinear system. The proposed algorithm entitled online RKPLS-RN kernel method uses the technique Reduced Kernel Partial Least Square (RKPLS) in an offline phase to construct a RKHS model with reduced parameter number. Then the Regularized Network (RN) method is used on online phase to update the reduced parameters of the RKHS model that determined in offline one using the RKPLS technique. The proposed algorithm has been tested to identify an electronic nonlinear system with a Wiener Hammerstein structure.

Keywords: RKHS, SLT, Kernel Method, Online Identification, RKPLS-RN, Wiener Hammerstein Structure.

by Sifuentes Mijares Juan, Meza Medina José Luis

Abstract - This paper presents a passivity-based analysis of a PID controller for robot manipulators where a theorem of interconnected passive systems is used to proof that the unique equilibrium of the system in closed loop is asymptotically stable in a global sense. The structure of the PID controller is formed by variable PD gains that improve system performance, allowing getting better transient responses, and a constant I gain. A controller with fixed gains is limited because it is not adaptable to new operation conditions. A system with variable PD gains and constant I gain is better because the gains are selected online and the integral gain avoid the necessity of calculate the gravity forces vector into the control law. As consequence variable PD gains and constant I gain make possible to obtain the most adequate torque output that get better response of the outputs. An evaluation in simulation to verify the theoretical results is realized.

Keywords: Passivity, PID Control, Variable Gains, Stability Analysis, Robot Control.