Omur Aydogmus

Comparison of Extended-Kalman- and Particle-Filter-Based Sensorless Speed Control

State estimation process is one of the major concerns for controlling and monitoring systems in industry which requires high-cost measurements or unmeasurable variables of nonlinear systems. These drawbacks can be highly eliminated by designing systems without using any kind of sensors. In this paper, sensorless speed control of a dc motor was performed by using extended Kalman filter (EKF) and particle filter (PF). The speed information is estimated by using armature current data measured from a dc motor which is controlled in various speed references with a closed-loop controller. Furthermore, a performance comparison of the EKF and the PF by taking into consideration their estimation errors under the same conditions was realized in a simulation environment. The comparison results showed that the estimation performance of the PF is more accurate but slower than the EKF. The quantitative values of accurateness and slowness are depended on the particle number of the PF. The obtained computation times of the PF having ten particles and the EKF are 180 and 15 μs, respectively.

An implementation of a novel vision‐based robotic tracking system

Purpose – The purpose of the paper is to present an approach to detect and isolate the sensor failures, using a bank of extended Kalman filters (EKFs) using an innovative initialization of covariance matrix using system dynamics.Design/methodology/approach – The EKF is developed for nonlinear flight dynamic estimation of a spacecraft and the effects of the sensor failures using a bank of Kalman filters in investigated. The approach is to develop fast convergence Kalman filter algorithm based on covariance matrix computation for rapid sensor fault detection. The proposed nonlinear filter has been tested and compared with the classical Kalman filter schemes via simulations performed on the model of a space vehicle; this simulation activity has shown the benefits of the novel approach.Findings – In the simulations, the rotational dynamics of a spacecraft dynamic model are considered, and the sensor failures are detected and isolated.Research limitations/implications – A novel fast convergence Kalman filter f...

A web-based educational tool using programmable logic controller-connected MATLAB-OPC server

Many technological developments contribute to the progress of the education system. Especially, engineering education is affected by the latest developments in internet technology. Therefore, the engineering education system has to keep up with developing technology by using web-based systems. This work provides a convenient method to improve students’ learning outcomes, their skills and their real-time experiences in multidisciplinary engineering education such as electrical, electronics, mechatronics and control engineering. In this study, a web-based real-time laboratory system was developed by using a programmable logic controller-connected MATLAB server via object linking and embedding for process control. The developed educational tool can be accessed on internet by the currently registered students. This remote accessible real-time mechatronic system consists of a programmable logic controller-connected MATLAB server, a water level tank, a servo pneumatic actuator, a pressure transmitter and two real-time cameras. The established system provides a real-time experience for students by using real instruments accessible on internet. This developed educational tool can be used as a complementary practice for some engineering courses such as sensors and actuators, control systems and industrial automation systems.

GA-based optimization and ANN-based SHEPWM generation for two-level inverter

Selective harmonic elimination (SHE) is a well-known PWM technique applied voltage source inverters (VSI) to control fundamental voltage and eliminate chosen harmonics. This technique requires the determination of optimum switching angles by solving the nonlinear equation set and a look-up table stored the switching times in a real-time application. This paper presents a hybrid genetic algorithm (GA) to optimize offline of optimum 11-switching angles for three-phase two-level inverter. In addition, the paper proposes two Artificial Neural Networks (ANN) based solution. The first ANN was trained by the data obtained from GA to calculate the switching angles without using a look-up table. Second ANN was trained by using these switching angles to generate PWM signals. GA and ANN are performed by using MATLAB environment. The ANN-based SHEPWM was designed to obtain inverter output voltage which has a bipolar waveform with quarter-wave symmetry. The waveforms of inverter output voltage and load current are analyzed with FFT for a RL load.

Design of a two-phase PMSM fed by an AC-AC converter

A two-phase permanent magnet synchronous motor is designed for using an AC-AC converter drive system fed from a single-phase source. This motor and drive system are proposed to replace with a traditional single-phase motors fed by electricity grid for improving the efficiency of the system. The proposed AC drive system can be connected directly between AC grid and motor without requiring any storage device such as DC-link large capacitors and rectification. The structure of AC-AC converter and modulation technique is presented with vector controlled two-phase PMSM. The converter output voltage and current waveforms and harmonic contents are analyzed with MATLAB simulation program. Additionally, responses of the motor speed and torque are presented for various conditions.

Modeling and simulation of 1-phase to 2-phase matrix converter motor drive

In this study, a novel direct ac-ac converter which contains one more leg in addition to the well known two-leg direct ac-ac converter has been proposed. Therefore, two output phases with 90o phase shift between them are obtained to drive a two-phase induction motor. Firstly, two passive loads consisting of resistances and inductances in series have been connected between these two legs to validate the control algorithm and converter operation. Then, the main and auxiliary windings of the single-phase induction motor have been connected to the output phases as a load. A phase difference of 90o has been obtained between the windings to generate maximum torque without using any starting capacitor. Thus, the phase difference between the windings has been provided by the proposed modulation algorithm. Model of the proposed converter and its load has been obtained by MATLAB/Simulink and the results of the simulation have been given under various operating conditions.

Four-quadrant operation of PMSM drive fed by a matrix converter

In this paper, a PMSM is fed by a matrix converter to perform four-quadrant operation. Combining a matrix converter and a PMSM results in an increase at the performance of the drive system. Especially, some of motor applications require motoring and regenerating operation such as cranes, hoists and lifts. Bi-directional power flow feature of the matrix converter is used for these type motor applications. In addition, the converter input current and output current waveforms are analyzed considering their harmonic spectra. This study has shown that the matrix converter is very effective solution for this type of motor applications.

Control and Design of a High Power Density PMSM

In this work, a motor having high power/volume ratio has been designed for robotic application. Permanent Magnet Synchronous Motor (PMSM) has been chosen in order to obtain high power/volume ratio. Optimization is achieved by using MotorSolve/Infolytica and Maxwell/Ansys analysis programs and PMSM is obtained for 25 Nm torque at 2000 rpm speed as rated values. Design information and performance values have been presented in details for designed motor. Additionally, the motor has been tested for different speed transitions at the same load condition by using MATLAB and the motor performance results have been analyzed. Vector control algorithm and a two-level voltage source inverter structure have been used for motor speed/position control.