Celik, Husamettin; Karaboga, Nurhan

Blind Source Separation is an optimization method frequently used in statistical signal processing applications. There are many application areas such as ambient listening, denoising, signal detection, and so on. In this study, a new Strength Pareto Evolutionary Algorithm 2-based signal separation method is proposed, which combines Multi-Objective Optimization and Blind Source Separation algorithms. The proposed method has been tested for denoising, which is widely used in biomedical signal processing. That is, the Electrocardiogram (ECG) and White Gaussian Noise are mixed together with normally distributed random numbers and the original signals of the mixed signals are obtained again. To evaluate the performance of the proposed method and others (Multi-Objective Blind Source Separation and Independent Component Analysis), the Signal-to-Noise Ratio (SNR) of the ECG signal obtained from mixed signals has been measured. As a result of the simulation studies, it is seen that the performance of the proposed method is satisfactory.

Can, Kaan; Orman, Kamil; Basci, Abdullah; Derdiyok, Adnan

In this paper, a fractional-order sliding mode controller (FOSMC) is designed and applied to a four-rotor unmanned aerial vehicle (Quadrotor) to perform trajectory tracking for different time-varying references. Because quadrotor's nonlinear system dynamics are effected by external disturbances and parameter variations easily, the FOSMC is used as a nonlinear controller to combine the flexibility of the fractional-order approach and the disturbance rejection characteristics of the integer-order sliding mode controller (IOSMC) to keep quadrotor on desired trajectory, as well as overcome parameter variations. In order to indicate the priority of the FOSMC, the IOSMC is also applied to quadrotor for the same references. The experimental results show that FOSMC is better than IOSMC in terms of error elimination and is good at dealing with parameter variations occurred while tracking the desired trajectory.

Orman, Kamil; Can, Kaan; Basci, Abdullah; Derdiyok, Adnan

n this paper, speed and direction angle of a four wheel skid-steered mobile robot (4 WD SSMR) has been controlled via adaptive-fuzzy fractional-order sliding mode controller (AFFOSMC) under different speed and angle reference signals. The hybrid control method is designed to combine all advantages that controllers have such as flexibility realized by fractional order calculation, robustness to disturbances and parameters variations provided by sliding mode controller (SMC) as well as adaptation of G constant of SMC via fuzzy controller, simultaneously. Also, a fractional-order SMC is applied to the system for the same reference speed and angle references to show the effects of the changes and adaptation of G constant. Experimental results show that the AFFOSMC has better trajectory tracking performance than the FOSMC.

Basci, Abdullah; Can, Kaan; Orman, Kamil; Derdiyok, Adnan

In this paper, a nonlinear Continuous Sliding Mode control (CSMC) application is presented for trajectory tracking control of a four rotor unmanned aerial vehicle (UAV) called the Quadrotor, also known as micro helicopter. The proposed controller is tested with different time-varying reference routes to provide a stable flight for position control. To show the effectiveness of the designed CSMC, well-tuned PI controller is also applied to quadrotor for the same routes. The current position of the quadrotor is taken from accelerometer, gyroscope and ultrasonic sensors. The experimental results show that the CSMC is adequate to dealing with parameter uncertainties occur in the system dynamics while flying and has satisfactory performance in terms of robustness against to disturbances and error elimination when it compared with PI controller.

Ozgenel, Mehmet Cihat; Bal, Gungor; Uygun, Durmus

Permanent magnet synchronous motors (PMSM) are recently getting involved in many usage areas such as industrial, robotic, home and office applications due to the fact that they have several advantages like fast dynamic response, low size, high efficiency, high power density and more reliability. Since PMSMs require rotor position information for phase current commutation, a position encoder is used on the rotor. Unfortunately, position sensor increases the size and cost of the driver system. In this study, a simple low cost position sensor based on photomicrosensor is proposed to replace the position encoder. A driver system for 12 poles PMSM with developed position sensor was set up and tested under different speed and load conditions. The experimental results proved that the PMSM driver is able to deliver sinusoidal currents to stator phase windings along with demonstrating the effectiveness of the proposed sensor.

Orman, Kamil; Basci, Abdullah; Derdiyok, Adnan

In this paper, speed and direction angle control of four-wheel drive skid-steered mobile robot (4WD SSMR) is realized by Fractional-Order Proportional Integral (FOPI) controller. Speed and direction angle of the mobile robot are calculated by using angular velocity of each motors. FOPI controller produces the torques of each motor of mobile robot for trajectory tracking and stabilization in the desired position. A well-tuned conventional PI controller is also applied to mobile robot for comparison with the FOPI. Experimental results prove that the FOPI shows better trajectory tracking performance than PI controller in terms of trajectory tracking accuracy and error levels.