Intelligent control of a stepping motor drive using an adaptive neuro–fuzzy inference system

Stepping motors are widely used in robotics and in the numerical control of machine tools where they have to perform high-precision positioning operations. However, the variations of the mechanical configuration of the drive, which are common to these two applications, can lead to a loss of synchronism for high stepping rates. Moreover, the classical open-loop speed control is weak and a closed-loop control becomes necessary. In this paper, fuzzy logic is applied to control the speed of a stepping motor drive with feedback. A neuro-fuzzy hybrid approach is used to design the fuzzy rule base of the intelligent system for control. In particular, we used the ANFIS methodology to build a Sugeno fuzzy model for controlling the stepping motor drive. An advanced test bed is used in order to evaluate the tracking properties and the robustness capacities of the fuzzy logic controller.     

永磁同步电动机混沌系统光滑二阶滑模控制

提出基于二阶滑模的控制方法控制永磁同步电动机（PMSM）中的混沌现象。利用Lyapunov函数构造了一种新的滑模面,能保证在滑模面上系统状态在有限时间内稳定到原点。控制器的设计采用了光滑二阶滑模方法,控制输入为光滑的函数,能有效消除抖振现象。仿真的结果也验证了控制方法的有效性。     

Detection of stator winding fault in induction motor using fuzzy logic

The online monitoring of induction motors is becoming increasingly important. The main difficulty in this task is the lack of an accurate analytical model to describe a faulty motor. A fuzzy logic approach may help to diagnose induction motor faults. This work presents a reliable method for the detection of stator winding faults (which make up 38% of induction motor failures) based on monitoring the line/terminal current amplitudes. In this method, fuzzy logic is used to make decisions about the stator motor condition. The fuzzy system is based on knowledge expressed in rules and membership functions, which describe the behaviour of the stator winding. The finite element method (FEM) is utilised to generate virtual data that support the construction of the membership functions and give the possibility to online test the proposed system. The layout has been implemented in MATLAB/SIMULINK, with both data from a FEM motor simulation program and real measurements. The proposed method is simple and has the ability to work with variable speed drives. The fuzzy system is able to identify the motor stator condition with high accuracy. This work is an example of the fusion between soft and hard computing.     

Controlling of transient and harmonics using UPFC in an interconnected power grid

Microsystem Technologies - The performance and transient stabilizing using a unified power flow controller (UPFC) anticipated for a grid consisting of parallel connected two number of three-phase...     

Controlling the order of moves in voting by veto. II. Algorithms for constructing an optimal order of moves

The study of issues concerning collective decision-making in complex systems using voting by veto is continued. A dedicated player is assumed to exist in the collective that forms the order of voting (order of moves) for the other participants. The problem of searching for the control strategy for the order of moves that ensures the win of alternative 1 that is preferable for the dedicated player is studied for the previously unstudied cases when such an order of moves exists. In particular, an algorithm for constructing such an order is proposed for the case when there is another participant for which alternative 1 is higher than the fourth from the end and when there is a group of participants that are relatively well-disposed to alternative 1 (more precisely, this alternative is higher than the third from the end for them). It is shown that the preference order of the alternatives that are better than alternative 1 is of no importance for the problem under consideration. It is proved that the conditions for the participants’ preferences that are sufficient for the existence of the desired order of moves (they were obtained in the first part of this paper) are unimprovable.     

Temporary short circuit detection in induction motor winding using combination of wavelet transform and neural network

Monitoring system for induction motor is widely developed to detect the incipient fault. Such system is desirable to detect the fault at the running condition to avoid the motor stop running suddenly. In this paper, a new method for detection system is proposed that emphasizes the fault occurrences as temporary short circuit in induction motor winding. The investigation of fault detection is focused on the transient phenomena during starting and ending points of temporary short circuit. The proposed system utilizes the wavelet transform for processing the motor current signal. Energy level of high frequency signal from wavelet transform is used as the input variable of neural network which works as detection system. Three types of neural networks are developed and evaluated including feed forward neural network (FFNN), Elman neural network (ELMNN) and radial basis functions neural network (RBFNN). The results show that ELMNN is the most simply and accurate system that can recognize all of unseen data test. Laboratory based experimental setup is performed to provide real-time measurement data for this research.     

Modelling the Richards function using Evolutionary Algorithms on the effect of electrical conductivity of nutrient solution on zucchini growth in hydroponic culture

The effect of two levels of electrical conductivity (EC) in two nutrient solutions was studied in a hydroponic cultivation of zucchini, during the growing period using the Richards function. The equations for each individual organ were fitted using Evolutionary Algorithms (EAs) and the improvement of parameters was defined through an innovative EA. So, by estimating the (near) optimal model of the growth of each individual organ, the proposed method manages to simulate the plant growth and how the two levels of EC in two different nutrient solutions affects it, as demonstrated by experimental results.The leaves were longer in the lower electrical conductivity. The length of the leaves and the growth rate of the older leaf were higher than those of the newer leaf in both nutrient solutions. The total soluble solids of fruits were more at the higher EC level.     

The existence of a solution for a fractional differential equation with nonlinear boundary conditions considered using upper and lower solutions in reverse order

Using the method of upper and lower solutions in reverse order, we present an existence theorem for a linear fractional differential equation with nonlinear boundary conditions.