Showing papers presented at "International Symposium on Industrial Electronics in 2009"

Modeling of a variable speed wind turbine with a Permanent Magnet Synchronous Generator

Abstract: The aim of this work is to analyze a typical configuration of a Wind Turbine Generator System (WTGS) equipped with a Variable Speed Generator. Nowadays, doubly-fed induction generators are being widely used on WTGS, although synchronous generators are being extensively utilized too. There are different types of synchronous generators, but the multi-pole Permanent Magnet Synchronous Generator (PMSG) is chosen in order to obtain its model. It offers better performance due to higher efficiency and less maintenance since it does not have rotor current and can be used without a gearbox, which also implies a reduction of the weight of the nacelle and a reduction of costs. Apart from the generator, the analyzed WTGS consists of another three parts: wind speed, wind turbine and drive train. These elements have been modeled and the equations that explain their behavior have been introduced. What is more, the whole WTGS has been implemented in MATLAB/Simulink interface. Moreover, the concept of the Maximum Power Point Tracking (MPPT) has been presented in terms of the adjustment of the generator rotor speed according to instantaneous wind speed.

3-D hand motion tracking and gesture recognition using a data glove

Abstract: Hand motion tracking and gesture recognition are a fundamental technology in the field of proactive computing for a better human computer interaction system. In this paper, we have developed a 3-D hand motion tracking and gesture recognition system via a data glove (namely the KHU-1 data glove consisting of three tri-axis accelerometer sensors, one controller, and one Bluetooth). The KHU-1 data glove is capable of transmitting hand motion signals to a PC through wireless communication via Bluetooth. Also we have implemented a 3-D digital hand model for hand motion tracking and recognition. The implemented 3-D digital hand model is based on the kinematic chain theory utilizing ellipsoids and joints. Finally, we have utilized a rule-based algorithm to recognize simple hand gestures namely scissor, rock, and paper using the 3-D digital hand model and the KHU-1 data glove. Some preliminary experimental results are presented in this paper.

Single-phase AC/AC converter based on quasi-Z-source topology

Abstract: This paper deals with a new family of quasi-Z-source converters applying to AC/AC power conversion called single-phase quasi-Z-source AC/AC converter (qZSAC). The proposed qZSAC inherits all the advantages of the traditional single-phase Z-source AC/AC converter (ZSAC), which can realize buck-boost, reversing or maintaining phase angle. In addition, the proposed qZSAC has the unique features; namely that the input voltage and output voltage is sharing the same ground; the operation is in continuous current mode (CCM). Compared to the conventional ZSAC, the proposed qZSAC has a lower harmonic distortion input current and a higher efficiency. The proposed qZSAC can control to shape the input current to be sinusoidal and in phase with the input voltage. The operating principles of the proposed qZSAC are described, and a circuit analysis is provided. Simulation results are shown in comparison to that of the conventional SZAC. Experimentation is implemented to verify the operational concept.

Identifying vulnerable lines in a power network using complex network theory

Abstract: The latest developments in complex network theory have provided a new direction to power system research. Based on this theory a power system can be modelled as a graph with nodes and vertices and further analysis can help in identifying the important lines. This paper proposes a new betweenness index using the reactance of the transmission lines as the weight and criteria to measure of vulnerability of a power network. The reactance is a simplified measure of power flow in a lossless transmission line based on the power flow analysis equations. The weighted line index is defined as the reactance of the electric path taken to reach from one node to another node. More power is transmitted along the lines with less reactance, to reach from the source node to destination node, which gives the edges with less reactance a higher weight in the analysis. The analyzes have been carried out on the IEEE 39 bus system and IEEE 118 Bus System. The new betweenness index can identify the critical lines of the system, either due to their position in the network or by the power they transmit along the network.

Development of a portable activity detector for daily activity recognition

Abstract: This paper presents a portable device for real-time daily activity identification. The proposed portable device is realized by an embedded system that integrates a triaxial accelerometer, a microprocessor, and a wireless transceiver module. An online activity recognition algorithm has been developed for human daily activity recognition based on the acceleration signal collected from the triaxial accelerometer. The proposed algorithm is composed of data collection, data preprocessing, feature extraction, feature reduction, and classifier construction. Our experimental results have successfully validated the effectiveness of the portable activity detector in terms of high accuracy.

Real-time rail head surface defect detection: A geometrical approach

Abstract: Rail head surface defect detection is a major issue for rail maintenance, which is mainly used to avoid railway accidents due to rail track failures. The aim of this paper is to present a new vision based inspection technique for detecting special Rolling Contact Fatigue (RCF) defects that particularly occur on rail head surface, meanwhile, an automatic detecting system is implemented, which consists of pre-processing, defect locating, defect identifying and post-processing subsystems. To realize the defect locating sub-procedure, a simple and fast algorithm has been proposed, which adopts geometrical analysis directly on a gray-level histogram curve (the first-order statistical texture property) of the smoothed rail head surface image. Experimental results show that the proposed algorithm has a higher precision and is more suitable than the baseline method for real-time rail head surface defect detection application.

Vision-based pest detection and automatic spray of greenhouse plant

Abstract: This paper proposes a new method of pest detection and positioning based on binocular stereo to get the location information of pest, which is used for guiding the robot to spray the pesticides automatically. The production of agricultural cultivation in greenhouse requires of big quantities of pesticides for pest control. Pesticides application is a major component of plant production costs in greenhouse, and the excess in their applications have a great negative impact on the environment. A pesticide application is ideal if the spraying coverage is presented as evenly distributed over the whole plant canopy and, if the product application is correctly adjusted for minimizing the losses towards the soil or the environment. In this approach, the difference of color features between pest and plant leaves is extracted by the image segmentation to identify pest. According to the results of image segmentation and binocular stereo vision technique, the 3D position of the pest has been obtained. In the process of position locating, centroid-matching technique is adopted to displace the common object-matching. The formula based on binocular stereo vision to measure distance is revised, additionally.

High efficiency battery management system for serially connected battery string

Abstract: This article presents an approach for balancing serially connected battery strings with high efficiency energy transferred. The efficiency of this balancing process is accomplished by channeling an excess energy through a DC Link Bus rather than done serially. Using this proposed technique with converter which was 80 percent efficiency, the equalized efficiency of balancing process is increased more than the conventional techniques at least 12.80 percent. By applied this proposed technique to the charge equalized system, the unbalance charging problem can be eliminated. The validity of this approach can be supported by computer simulation and experimental result.

Efficient hybrid distributed genetic algorithms for wind turbine positioning in large wind farms

Abstract: An efficient hybrid distributed genetic algorithm is proposed to determine the proper number and locations of wind turbines in large wind farms. The objective of this optimal process is to find a solution that maximizes the annual profit obtained from a wind farm. It is well-known that genetic algorithms are good for global searches, but are weak for local searches. To improve the performance of finding the optimal solution in a large search space, the hybrid methodology combines a distributed genetic algorithm and steepest ascent hill-climbing local search algorithms. The hill-climbing algorithm provides a powerful strategy for searching the local optimal solution by exploring the neighborhood of the current state. In this paper, the hill-climbing algorithm is further enhanced by a heuristic method to reduce the execution time for finding the optimal value. Test results show that this proposed hybrid distributed genetic algorithm adequately demonstrates its effectiveness in solution quality and execution time.

Losses and CMV evaluation in transformerless grid-connected PV topologies

Abstract: Controlling the thermal losses in the semiconductors as well as the Common Mode Voltage (CMV), are important issues in the design of power electronics converters for photovoltaic applications. At present time there are several topologies that offer a good performance regarding losses and CMV. In this paper an evaluation of three of these converters topologies: H5, HERIC and NPC transformerless for single phase PV systems will be carried out by means of simulations performed with PSIM 7.05. This software permits to estimate accurately the switching and conduction losses, thanks to its Thermal Module. This analysis together with the CMV study for each case will permit to establish the pros and cons of each topology.

Photovoltaic inverters with fault ride-through Capability

Abstract: This paper presents a new control strategy that allow the photovoltaic system operate under grid faults without overpass the rated current and assuring sinusoidal currents. In the classic control strategies used in photovoltaic systems the power delivered to the grid remains constant when a fault occurs, hence the current can reach dangerous values. Therefore the converter has a protection system to disconnect it avoiding its damage. Thus it must be connected manually when the electrical grid is re-established. The strategy presented here overcomes these drawbacks. It is compared with the classic strategy through simulations in PSCAD and the experimental results prove its effectiveness.

Predictive brake warning at night using taillight characteristic

Abstract: We present a technique used for frontal collision warning in an intelligent vehicle. The system uses an image processing algorithm to detect taillights (red brake lights) of vehicles driving at night time. The area of red lights, the size of the largest brake lights, and the vehicle's speed are used to compute the rear-end collision risk, which can be used as an indicator to danger that potentially leads to frontal collision. Therefore, the driver can be warned, and he can perform brake action on time. The algorithm uses a threshold to detect red color on an RGB image. The thresholds are obtained from statistical collection of 50 sample images. From our experiment on real driving situation, the collision risk can predict the actual brakes with 90% accuracy. The result also indicates that the area of red lights detected has a close relationship with the brake applied.

A proposed photovoltaic module and array mathematical modeling destined to simulation

Abstract: Photovoltaic applications are increasing rapidly, thus, an accurate photovoltaic module modeling is requested in order to allow photovoltaic plants simulations. This paper presents a mathematical modeling to describe numerically photovoltaic modules and arrays, taking into account the radiation and temperature effects on output voltage, current and power. A comparison between simulation and experimental results are presented, considering the Kyocera KC200GT module data-sheet information.

Direct current measurement based steer-by-wire systems for realistic driving feeling

Abstract: In this paper, a method to reproduce realistic driving feeling and improve the returnability of steer-by-wire systems (SBW) is proposed by measuring the roadwheel motor's current directly. The key contribution presented here is a novel method to recreate the driving feeling in term of force feedback with simple and cheap current sensors. A current sensor is used to fully measure the steering torque on the rack of steering mechanism. This measured steering torque therefore, includes the overall effects of road conditions, aligning moments, tire properties and so on. Beside that, a free control scheme is proposed to improve returnability as well as the handwheel stability in a free motion. Moreover, during this research, the significant frequency effect of handwheel motions was found. This effect could be useful and valuable for improving steer-by-wire development based on torque-map based method. This method is investigated with simulation results using the control design and simulation module in LabVIEW programming language. The simulated results show that this method offers a cheaper and simpler solution for the development of steer-by-wire systems. In addition, stability and returnability of handwheel in steer-by-wire systems could be improved.

An adaptive carrier-based PWM method for four-switch three-phase inverter

Abstract: This paper proposes an adaptive carrier-based pulse width modulation (PWM) for four-switch three-phase inverter. The balanced output currents are guaranteed by this proposed method instead of voltage oscillations across two dc-link capacitors. The linear over-modulation can be easily obtained with this new approach. Simulation and experimental results are shown to validate the feasibility of the proposed method.

A new high power efficiency cascaded U cells multilevel converter

Abstract: In this paper, authors presents a novel competitive multilevel converter. The novel cascaded U cells topology is constituted from two power switches and one capacitor for each cell. In case of DC/AC conversion, the proposed fifteen level inverter allows a nearly sinusoidal output voltage resulting on a perfectly sinusoidal load current. In case of AC/DC conversion, the proposed fifteen level rectifier presents a reduced impact on the utility supply, a good energetic efficiency and a small number of power switches and passive components. An average model of the proposed converter is performed and a control strategy is designed in order to draw a nearly sinusoidal current and voltage. Active and passive filters can thus be avoided resulting on a highest energetic efficiency and a reduced installation cost. The proposed converter presents also the possibility and the simplicity of changing the number of voltage levels only by acting online on the ratios of the desired output voltages. The modeling and control strategy of the proposed fifteen level converter were verified by simulation.

Electrical load simulator based on velocity-loop compensation and improved fuzzy-PID

Abstract: Research on electrical load simulator (ELS) which is directly driven by permanent magnet synchronous motor (PMSM), and build up mathematical model of ELS. Analyze the couple relationship between torque motor and actuator, and the generating mechanism of extraneous torque in ELS, conclude that extraneous torque is directly related to the velocity of actuator, so propose velocity-loop compensation algorithm to eliminate extraneous torque of ELS. Aiming at requirement of high frequency response and kinds of nonlinear factors of ELS, the traditional PID control theory cannot meet the demand of control accuracy, so research on fuzzy control with non-uniform membership function, then combine fuzzy control and PID control with exponential function to avoid the sudden change of control output when switching between fuzzy and PID. And the results of experiments prove that ELS based on velocity-loop and improved fuzzy-PID has excellent performance.

Thermal imprint feature analysis for face recognition

Abstract: Recently, vein pattern biometrics has attracted increasing interest from both research and industrial communities. The properties of uniqueness, stability and strong immunity to forgery of the vein patterns would make a potentially good biometric trait offer secure and reliable features for person identity verification. In this paper, a novel approach for personal verification by analyzing the face patterns formed by thermal imaging is presented. A new feature set is proposed to represent the thermal face: the bifurcation points of the thermal pattern and the geographical gravity center of the thermal face region. We proposed to use the Modified Hausdorff Distance to measure the similarity between two feature vectors of the thermal face. The work in this paper shows that the thermal face patterns can provide a reasonable level of discriminating power, and has the potential to be used in the context of biometric applications especially when used in conjunction with other biometric modals.

On design of two-stage CIC compensation filter

Abstract: This paper presents the compensation filter design for the two-stage CIC decimation filter. The goal is twofold: to avoid the integrator section at high input rate and obtain a low wideband passband droop of the overall filter. To this end the decimation is split into two stages with the cascaded less order RRS filters at each stage. The first stage can be implemented either in non recursive form or using the polyphase decomposition. The simple compensation filter and the sharpening are applied to the second section where RRS filter is implemented as a CIC filter. The resulting structure is a multiplierless and with no integrators at high input rate. Additionally, the structure exhibits a low passband droop and a high stopband attenuation.

Position estimation for mobile robot using in-plane 3-axis IMU and active beacon

Abstract: In most cases, indoor environment is unstable because of floor condition, obstacles and room noise. So, to elevate accuracy of robot position data at unstable condition, a robot navigation system needs to apply diverse sensor fusion methods. This paper presents a navigation system consisting of a MEMS-based digital in-plane 3-axis IMU (Inertial Measurement Unit), an active beacon system and an odometer to obtain more precise robot position data and to monitor robot movement in real-time. Two accelerometers and one gyroscope compensate the non-systematic errors of an odometer and perceive collision, bounce and slippage. Besides, fusing data of an IMU and an odometer can provide robot position data when an active beacon is losing its signal. When relative robot position data is unreliable, an active beacon system provides the absolute position data of the robot. To reduce noise of input sensors signal, low-pass filter and Kalman filter are applied. The sensor data from an in-plane 3-axis IMU, an odometer and an active beacon system are combined to obtain a precise navigation system. Results from two experiments in a real environment show that accuracy of robot position is elevated and that robot position data is not lost irrespective of robot's environment.

A new hybrid series active filter configuration to compensate voltage sag, swell, voltage and current harmonics and reactive power

Abstract: This paper proposes a new system configuration for a series hybrid power filter (SHPF) realized for all harmonic types of loads. The series hybrid filter consists of a small rated series active power filter (SAPF) and a shunt passive filter with variable inductance using a thyristor control reactor (TCR). The DC voltage available at the load side of a typical voltage harmonics source, such as a diode bridge rectifier followed by a capacitor, is utilized as a source of DC power for the SAPF. To increase the filtering performance of the shunt passive filter, SAPF is control in such a way that it increases the network impedance at the harmonic frequency. This also helps to avoid any series or parallel resonance that may occur. The shunt passive filter together with a TCR is used to support the variable load reactive power demand as well to tackle the current harmonics generated by non-linear load. The performance of proposed series hybrid power filter is validated through MATLAB/Simulink simulation study and successfully utilized to compensate the voltage sag, voltage swell, voltage harmonics, current harmonics and load reactive power demand.

A monocular vision based advanced lighting automation system for driving assistance

Abstract: This paper presents a night time vehicle detection system performing automatic headlamp control in the frame work of driving assistance. In such application dealing with sensor, processing and actuator, we focus on image processing techniques developed in this project. From our embedded camera, image processing enables to detect vehicles ahead and estimates their positions in order to increase driver visibility by adjusting headlamps. We review algorithms (segmentation, classification, tracking and position estimation) in detail and present results comparing driver dazzling between static headlamps and intelligent headlamps. Our system detection range is above 600m for headlamps and about 400m for tail lamps which is sufficient to avoid glaring of other road users. Classification performances are above 97% of true positive rate evaluated on a validation database (frame by frame detection). The final vehicle detection is guaranteed at 100% of recognition by attributing a minimum confidence accumulated over successive fames. By way of conclusion, we introduce perspective of advanced lighting automation.

A double-loop current control strategy for Shunt Active Power Filter with LCL filter

Abstract: Shunt Active Power Filter (SAPF) is suitable to compensate current-type harmonics caused by nonlinear load, but high compensation precision is difficult to be obtained due to very high slew rate of harmonic current, output impendence of Voltage Source Converter (VSC) and control loop phase lag. LCL-filter with high attenuation ratio and small LC parameters is appropriate to be used as output filter considering the mentioned reasons. However, LCL-filter, as a third-order resonant circuit itself, is difficult to be stable. This paper proposes a novel control strategy for shunt active power filter with a LCL output switching filter. It integrates an outer loop of grid-side filter current regulator and an inner control loop of capacitor current feedback, which essentially imitates an active damper or a virtual resistor. Based on this double-loop control scheme, the SAPF can dramatically improve its efficiency and high quality steady-state grid current waveform and fast-dynamic response can be obtained even under the case of serious distorted grid voltage. Analysis and simulation results validate the correctness and feasibility of the proposed control strategy.

Dynamic simulation model for hybrid electric scooters

Abstract: This paper presents a dynamic simulation model for a hybrid electric scooter (HES) designed by NPUST in Taiwan. The HES is built in a parallel hybrid configuration with a 24V 370W auxiliary power electric motor, a 24V 600W generator, a 24V15AH battery, and an electronically controlled fuel injection internal combustion engine (ICE). Because the system is complex and nonlinear in nature, the simulation model utilizes mathematical models in tandem with accumulated experimental data. The methods used to construct the model and to prepare experimental data are fully described. Efforts are made to accurately predict key system parameters including engine speed, velocity, CVT gear ratio, battery state of charge (SOC), and fuel consumption rates during an ECE-40 driving cycle test. The efficacy of the model was verified experimentally with a scooter chassis dynamometer; parameters predicted by the simulation model are seen to be in excellent agreement with those of experiments.

Smoke detection in open areas using its texture features and time series properties

Abstract: In extensive facilities such as port facilities, chemical plants, and power stations, it is important to detect a fire early and certainly. The purpose of this paper is to present a new smoke detection method in open areas, as smoke is considered as a significant signal of the fire. It is assumed that the camera monitoring the scene of the open area is stationary. Since smoke does not keep stationary shape or image features like edges, it is difficult apply ordinal image processing techniques such as the edge or contour detection directly. In this paper, we propose a novel method of the smoke detection in an image sequence, in which we combines the several images techniques to detect smoke. We apply it to images of open areas under general environmental conditions. First, moving objects are detected from gray.scale image sequences, and then the noise is removed with the image binarization and the morphological operation. Furthermore, since the smoke pattern must be examined, the smoke feature is extracted with the texture analysis. Then, to obtain the final result of the proposed method, we discussed the properties of the proposed features as the time series data.

Sliding mode control with sliding perturbation observer for surgical robots

Abstract: Minimally invasive surgery (MIS) robot is made like a long cylinder with small diameter that can fit through a small incision thus decreasing the amount of healthy tissue damaged. Because of the shape of the surgical robot, the cable-driven mechanism is using to the robot. However this is a highly nonlinear system so the performance of the system is not so good. This paper applied a robust motion control algorithm. The algorithm uses partial state feedback for a class of nonlinear systems with modeling uncertainties and external disturbances. The major contribution is the design of a robust observer for the state and the perturbation of the instrument of the surgical robot, which is combined with a variable structure controller (VSC). The combination of controller and observer provides the robust routine called sliding mode control with sliding perturbation observer (SMCSPO). The control performance of the proposed algorithm is evaluated by the simulation and experiment to apply to a two-degree-of-freedom (DOF) robot arm. The results showed high accuracy and good performance.

Vibration control of flexible joint manipulator using input shaping with PD-type Fuzzy Logic Control

Abstract: This paper presents investigations into the development of input shaping with Proportional-Derivative (PD)-type Fuzzy Logic Control for trajectory tracking and vibration control of a flexible joint manipulator. To study the effectiveness of the controllers, a PD-type Fuzzy Logic Controller is developed for tip angular position control of a flexible joint manipulator. This is then extended to incorporate input shaper control schemes for vibration reduction of the flexible joint system. The positive zero-vibration-derivative-derivative (ZVDD) and new modified specified negative amplitude zero-vibration-derivative-derivative (SNA-ZVDD) input shapers are then designed based on the properties of the system for vibration control. The new SNA-ZVDD is proposed to improve the robustness capability while increasing the speed of the system response. Simulation results of the response of the flexible joint manipulator with the controllers are presented in time and frequency domains. The performances of the PD-type Fuzzy Logic with input shaping control schemes are examined in terms of input tracking capability, level of vibration reduction, robustness and time response specifications. A comparative assessment of the positive ZVDD and modified SNA-ZVDD shapers to the hybrid system performance is presented and discussed.

Ultra light weight fuel cell electrical vehicle (UL-FCV)

Abstract: This paper describes the concept of an ultra light weight fuel cell electrical vehicle (UL-FCV), and the results of its running experiments. The UL-FCV is a one-person operated fuel cell vehicle designed for ECONO MOVE, a Japanese light weight electrical vehicle competition held every May in Akita, Japan. Vehicles are powered using two 60 NL hydrogen tanks and are evaluated based on the distance traveled over two hours on a test course. One lap of the course is approximately six kilometers. This paper will first outline the ECONO MOVE competition, and also present the results of our preliminary running experiments and the competition. Next, we will present the experimental results of the improvements of the fuel cell driving system. Our experiments were conducted focusing on the efficiency of the hydrogen flow rate.

Automatic defect classification of TFT-LCD panels using machine learning

Abstract: Defect classification in the liquid crystal display (LCD) manufacturing process is one of the most crucial issues for quality control. To resolve this constraint, an automatic defect classification (ADC) method based on machine learning is proposed. Key features of LCD micro-defects are defined and extracted, and support vector machine is used for classification. The classification performance is presented through several experimental results.

A novel dynamic observer and torque ripple minimization via fuzzy logic for SRM drives

Abstract: This paper presents a high performance switched reluctance motor (SRM) drive based on dynamic observer. The dynamic observer estimates the rotor position and speed for wide speed range. As well, observer gains online will be corrected by using fuzzy logic hybrid algorithm (FLHA) with concern of estimation errors. In addition, a fuzzy logic current compensator (FLCC) for reducing torque ripple has been presented. In the regions that torque reduces, the FLCC, inject additional current for each phase currents. This drive has been simulated with MATLAB/SIMULINK for nonlinear model of SRM. Simulation results show that proposed drive will estimate the rotor position and speed with high precision for all speeds (near zero speeds up to rated speed). Also, FLCC minimize the torque ripple and reduce speed estimation error, too. This drive has the advantages of robustness, high reliability and excellent performance at steady state.