Journal of Majlesi Journal of Mechatronic Systems
Volume:9 Issue: 1, Mar 2020

This paper focuses on variable speed wind turbines operation with pitch control. An advanced control strategy is proposed based on linear quadratic regulator and fuzzy controllers in order to improve the performance of the variablespeed wind turbine. The proposed controller is designed to reduce rotor speed variation and optimizing wind turbine power. Wind turbine states are estimated by using fuzzy observer. Moreover, the Takagi-Sugeno fuzzy strategy is used to regulate the rotor speed by controlling the rotation of blades. The proposed method is implemented on MATLAB software by SimWindFarm simulator. Simulation results proved that the fuzzy TS method is appropriate in improving efficiency of wind turbine. Moreover, the proposed method shows better performance compared to the PI controller.

There are several methods for parameter identification and estimation in linear and nonlinear multi-input and multioutput systems. The method of detecting and identifying system parameters in a simulated auto correlated system with a minimized error between the target data and output results is affected by noise. After adding the summed noise to the input data, the system coefficients are determined in the least-squares algorithm. The trend of system error changes decreases with increasing number of input samples, but this does not mean that the estimation error decreases with increasing iteration with increasing trend. In other words, the number of samples given to the system in order to obtain a specific error does not decrease with increasing number of replications. Also, reducing the estimation error of the system is more dependent on input data than on data replication.

Automated motion detection and tracking is a challenging task in traffic surveillance. In this paper, a system is developed to gather useful information from stationary cameras for detecting moving objects in digital videos. The moving detection and tracking system is developed based on Gaussian Mixture Model (GMM) estimation together with applicable and combination of various relevant computer vision and image processing techniques to enhance the process. To remove noises, median filter is used and the unwanted objects are removed by applying thresholding algorithms via morphological operations. In addition, the object type restrictions are set using blob analysis. The results show that the proposed system successfully detects and tracks moving objects in urban videos.

In modern power system, need for flexibility, accuracy and fast response is growing everyday. Voltage instability affects the system's reliability and security. FACTS devices are used to restore voltage and to control the weak bus. SVC provides the fast acting dynamic compensation in case of severe fault. This paper is focused on voltage stability improvement of IEEE-14 bus test system. Simplified voltage stability index (SVSI) is calculated to identify the weakest bus of the system. All the analysis is being performed using PSCAD simulation software.

Rehabilitation of patients with neurological and spinal cord injuries is conducted to improve brain flexibility and patient performance. The performance of rehabilitation robots requires high standards of safety and reliability due to their direct interaction with humans during therapeutic motions. One of the simplest robot arms is a Two degrees of freedom Robot Manipulator that its function is considered as the basis for the performance of other arms. Due to the nonlinear dynamics, the control of two degree of freedom arm face challenges. Due to its simplicity and low cost, a robust PID controller is used first. Next, the Mamdani and Sugeno fuzzy controllers are designed which include two inputs, namely error and error derivative, and torque output. Finally, the hybrid fuzzy controller is designed as the first joint of the robot using robust PID control, and the second joint using the Mamdani fuzzy control. Comparison of control methods shows that the fuzzy Momdani fuzzy controller at both axes provides the most limited torque for the joint engines. The most accuracy of working point is the fuzzy hybrid control. Sugeno control shows the maximum speed and torque.

This paper presents a Dynamic Matrix Controller (DMC) for six-degree-of-freedom (6-DOF) Stewart platform based on the parallel mechanism in order to track the reference trajectory in the mechanism workspace. Dynamic matrix control is a particular type of model predictive control (MPC), which are framed as advanced controllers. This controller is an industrial controller that is utilized based on the system step response coefficients. The DMC showed robust performance for different size of input signals, and prediction and control windows. This method is a generalization of pole placement methods and optimal control. In addition, this method showed good tracking performance and benefit when considering input or output constraints, which is often the case in real industrial systems.