Earticle

To eliminate control error of water level, this paper researches the control algorithm of water-tank in water level control system, and uses the fuzzy controller to improve the control performance, two-dimensional fuzzy controller is designed taking advantaging of Fuzzy Logic Controller, set up the structure mode of the water-tank water level control system according to the characteristics of the water-tank water level control system, give the simulation result of the performance of the fuzzy controller, acquiring waveform graphs of real water level and fixed level, and compared with PID controller. The simulation results show that the fuzzy controller has better control performance than the PID controller.

This paper suggests a simple method to solve the clock skew problem generated on two or several separate chips when voltage difference, or gradient, occurs between/among the chips. Generation and distribution of clock signals with minimum skews becomes a critical factor in overall system performance in today’s GHz operation speed. With a few connection lines, similar to Data Bus, between two chips, named CBL (Clock Bus Line), a multi-chip synchronization method is newly proposed and proved through simulations and TTL chip measurements. With 2% of supplied voltage differences in different chips, within 3% of the period clock skew is guaranteed in this new scheme. A feasible way of implementation of this CBL method in today’s integrated circuits is also described along with CMOS layout.

A set of accelerated aging and automatic test system for IGBT modules is designed in this paper, including platforms of accelerated aging and parameter automatic test. Aging test platform is controlled by IPC, using DC power cycling methods and water cooling to heat dissipation. Combined with LabVIEW and high-speed digitizers, single pulse switch testing is achieved in automatic test platform through hardware circuit. In different stages of the IGBT module aging tests, change trend of each electrical parameters were measured under different working point. Collector-emitter conduction voltage drop VCE(sat), gate-emitter threshold voltage VGE(th), turn-off time toff, the current and voltage waveform during turn-on and turn-off are measured. The relationship between these electrical parameters and aging degree of the IGBT module is researched. It would be able to characterize the device and seek out external indicators of fatigue aging, reliable evidences for state assessment. Compared with the traditional manual testing methods, the automatic test system has characters: high accuracy, test speed, short development cycle and so on.

Combinatorial testing has been proved to be an efficient strategy in software testing. The research on automatic test case generation for system level based on components with constraints is a challenging but significant problem by using combinatorial testing. This paper focuses on the test case generation for system level based on components with sequential constraints. There are three main contributions: 1) the new test case generation strategy for system level is proposed based on IPOG (In-Parameter-Order-General) algorithm; 2) a filling strategy for don’t care positions is given to enhance the higher strength coverage for system level, which can improve the quality of the generated test suite; 3) a randomized post-optimization algorithm is applied to reduce the size of the test suite for system level. Experimental results show that the proposed filling strategy can improve the quality of the covering array, the post-optimization algorithm has a good optimization effect on reducing the size of the array, and trades off better between the size of the covering array and computational time than simulated annealing (SA).

This study proposes a way to generate a virtual lane by using a vehicle’s driving tra-jectory during the operation of a V2V-based vehicle. The existing method of road shape detection using Lidar, Radar, and camera sensors has limitations in the range of detec-tion with blind spots. To overcome such limitations, a method to generate virtual lanes was proposed to detect the road shape along with the driving trajectory of the leading vehicle based on V2V communications. A Clothoid road model was applied for the calcu-lation of the driving trajectory of the leading vehicle. A driving scenario with various changes in curvature of road was also configured. Furthermore, the feasibility of the vir-tual lane generation method was verified by comparing the reference virtual lane and the virtual lane generated by the driving trajectory. The simulation results confirmed the us-ability of the virtual lane generated from Clothoid road model.

A novel speed controller for permanent-magnet synchronous motor (PMSM) is proposed. With the usage of an analytical two-degree-of-freedom (2DOF) proportional integral (PI) controller design method in speed control, good speed-reference tracking and good load-torque rejection can be achieved simultaneously. A “back calculation and tracking” anti-windup (AW) method is used to deal with the “windup” problems. In both simulation and experiment, the proposed designs are shown to exhibit satisfactory performance.

The global growth of Photovoltaic (PV) is remarkable with a total of 135 GW in 2013 from 10GW in 2007. Operation of PV has changed from standalone to grid-connected which brings several challenges. This sudden spike in PV capacity is due to the reduced cost of PV modules over five times in last six years and followed by advancements in PV inverter technologies. Integration of distributed generation alters the unidirectional power system to bidirectional and alongside present’s issues such as overvoltage on distribution feeders, overloading of feeders, and undesired exchange of reactive power. Traditional methods that are in practice to control the voltage and reactive power is by controlling the transformer tap changer and using capacitor banks. Volt-VAr control (VVC) activities by traditional methods are no longer appropriate due to intermittency solar irradiation caused by cloud transients. Modern PV inverter has the capabilities to mitigate voltage related issues when they are allowed to operate at power factor other than unity as stated in the IEEE1547-a. Germany and Spain are the pioneer countries in adopting ‘smart’ inverter operation in accordance with their countries interconnection grid guidelines. Similar operation of PV inverters for Malaysian scenario is prohibited as the current guideline does not allow the participation of PV inverters in voltage control activities. Therefore it is essential to allow the operation of smart inverter for Malaysian scenario, as the number of grid connected PV system is on the rise. This paper extensively analyses the performance of the DigSILENT’s PV model control aspects in terms of active power reduction and dynamic voltage support in a test network and validation of static voltage support on modelled Malaysian distribution network according to the new German Grid Code.

The boiler drum water level control system is one of the most important components of a power plant. The operating water level control system is increasingly recognized as a capital asset that should be routinely maintained and monitored. The performance assessment technology can achieve measures of the level of difficulty in controlling the water level from routine operating data, however, which is still an open problem; thus, in this paper the performance assessment technology will be brought into the feedforward-cascade drum water level control system. The performance benchmark and the associated benchmark controller are also proposed. A numerical example for the drum water level control system shows the effectiveness of the proposed method.

Container crane simulator is an important tool for driver training to increase the operation safety. Motion platform is always used for providing the motion perception for the crane simulator, and is also the critical approach to improve the simulation fidelity for the high-end simulator. Based on the designed parameters and the operation mode of the container crane, a novel design method of the container crane simulator motion platform is proposed in this work, which includes the work space design of mechanical component and the technical specifications analysis of the platform According to the principle of human-being’s motion perception, we design the control wash-out algorithm which is the core part to determine the platform how to work.. We use the simulation tool to optimize the parameters of the filters and evaluate the performance of the motion platform whether can satisfy the requirement of crane simulator. Viewed from the running in the field, the motion platform has been developed completely and used for one type of the crane simulator, which validates the method proposed by this work that can be applied for the container crane simulator.

With a growing population and industrial development, the destruction of ecosystems because of the development of expressways, national highways and tracks increased, and accordingly, the phenomenon of the fragmentation of wildlife habitats increased. Thus, the damages caused by harmful wild animals frequently occur, in South Korea, efforts are made, like saving some damaged farmhouses through monetary compensation. However, the damaged residents cannot sleep at night due to night patrolling or have a lot of inconveniences in their basic life. This study researched and developed a discontinuous system using a UAV (Unmanned Aerial Vehicle) to prevent the access of wild animals in a certain range generating and regenerating ultrasound and ultra-low sound frequencies, based on research on the ecology and habits of wild animals.

In order to improve the system performance affected by the model uncertainties and loading moments, a robust tracking controller is proposed for electro-hydraulic servo system. Considering the conventional disturbance observer (DOB) lacks the enough ability in estimating the whole disturbances in electro-hydraulic servo system, one global sliding mode controller (GSMC) is proposed based on the inner-loop DOB. The GSMC not only suppresses the remainder disturbances which cannot be observed by DOB, but also realizes the position tracking of electro-hydraulic servo system. Simulation results present that, compared with other traditional control schemes, the proposed robust control scheme can ensure electro-hydraulic servo system possess higher tracking precision. Moreover, there is no obvious high-frequency chattering at control input, therefore it also possesses higher application value.

Grid-connected inverter plays a significant role in wind power generation system for energy transmission and power factor regulation. The traditional control strategy based on PI-type current controller and grid voltage vector-oriented control is analyzed firstly. Then, the fuzzy PI controller of voltage loop is designed. According to the errors of input value and its ratio, it can adjust PI parameters in real-time on the basis of fuzzy rule. The experiment results indicate that the proposed method has a good sinusoidal current, a fast dynamic response and a perfect system performance.

Optimization is ability of find the best solution in the existing situations. Optimization is used in design and maintenance of systems engineering, economic, social and even necessary to reduce costs and increase profits. The widespread importance of optimization problem has a lot of grown. There are many algorithms for optimization and they are trying to reduce the disadvantages of other methods and increase the ability of resolve the problem. This paper proposed an adaptive ABC and Bat algorithm. The idea of algorithm is improved speed of convergence and optimized search in search space for ABC algorithm with Bat algorithm. The proposed algorithm is compared with ABC and Bat algorithm on benchmark function and test shows ABC_M are improved obviously. Also can be known a complete local search is more important from global search.

In this paper, an observer-based finite-time control approach for robotic manipulators with uncertainties is proposed. First, a nonlinear observer is introduced to guarantee the finite-time convergence of the unmeasurable joint velocities, and a finite-time controller is designed based on the estimated velocities. Second, in the presence of uncertainties, a nonlinear sliding mode observer is further developed to guarantee the robustness to uncertainties. The proposed observers and the controllers are all finite-time convergent. The validity of the proposed methods are demonstrated by the simulations on a two-link robotic manipulator.

Nanoscience and nanotechnology involve the ability to see and to control individual atoms and molecules. A quantum-dot cellular automata(QCA) is one of the attractive alternative technology among nanotechnology solutions. Demultiplexer is used in communication systems to convert the serial data to the parallel data. A demultiplexer receives the output signals from the multiplexer. For that reason, it is important components for making integrated circuit. This work target is designing a high optimized demultiplexer in QCA framework. We proposed designs of 1:2 and 1:4 demultiplexer and the simulation results reveal that our proposed designs have significant improvements, such as low complexity and power consumption aspects.

The short-range inertial aircraft has a short flight time, and its flight accuracy is influenced by various disturbance factors, and it is highly difficult to control the guidance. In this paper, various disturbance influences on the flight accuracy of ignoring after launching” aircraft is researched, through the mathematical modeling of such kind of aircraft and the mathematical modeling of various disturbance factors, the corresponding disturbance flight disturbance trajectory is analyzed under the influence of many disturbance factors like crosswind, initial disturbance and thrust eccentric, and it is concluded that the position control inertial guidance is a good plan, which can effectively eliminate the crosswind disturbance influence, then the engine thrust curve is relatively curve, the axial accelerometer can be omitted. For the above inertial guidance plan, the accuracy of angular position gyroscope on the aircraft is an important factor to decide the inertial guidance accuracy of the aircraft, thus providing key technical basis for the comprehensive evaluation of overall aircraft plan and the deep research of aircraft.

In this paper, a general voice activity detection (VAD) method based on pattern recognition is proposed, and a specific algorithm of endpoint detection is researched. In this method, the Extreme Learning Machine (ELM) and Genetic Algorithm (GA) optimization Support Vector Machine (SVM) is used as the training and recognition model. The simulation results indicates that ELM and GA-SVM have the same superior endpoint detection accuracy, and recognition time were similar, but the training time of ELM only up to a 1/2000 of the GA-SVM, the robustness of ELM and GA-SVM is greatly improved in noisy environment compare with the traditional VAD that depends on time-domain energy and zero crossing rate.

The purpose of this study is to enhance control capability of river water quality and environment by developing algal bloom monitoring technology using Unmanned Aerial Vehicle. The study acquired remote sensing data using UAV on the midstream area of Nakdong River, one of four major rivers in South Korea. The study also conducted water quality analysis and spectral reflectance measuring in the field to identify emergence aspect of phytoplankton in waters of the river and to induce algal bloom detection index equation through wavelength mixing of sensors. The result showed that the result values of algal bloom detection obtained from wavelength band mixing had strong positive correlation with algae standing crops. Besides, the results of analyzing spatial distribution of algal bloom of the overall investigated water area showed that the area of 0.22 km2 ~ 0.26 km2 had severity equivalent to the level of warning (5,000 ~ 1,000,000 cells/mL) in 2015 criteria for issuing algae warnings. It is expected that when this remote water quality and pollution monitoring technology is applied in the field, it would be able to improve capabilities to deal with the river water quality and pollution at the early stage.

Both traditional grinding and micro cold pressing are conducted to compare the micro surface morphologies of cold work mold steel specimen. Surface roughness, hardness and surface morphologies are analyzed under varying feeds of ball end cutter in Y direction and Z direction in MCP. The friction coefficients and wear rates of two types of specimen under oil lubrication are obtained through friction and wear test. After micro cold pressing, hardness increases from 0.11 to 0.099, with surface roughness reduced from 5.496μmto 1.871μm and wear rate reduced from 0.0506μm to 0.0153μm (Wear rate is measured in Z direction). The study shows that during micro cold pressing the ball end cutter flattens wear scar, which reduces surface roughness. Surface roughness is related to DY and DZ. Under fixed DZ, reduction in DY leads to an increase in flatness of specimen surface. Since work hardening takes place during micro cold pressing, surface hardness of specimen has improved with the greatest increment at 169.6HV.Grooved surface morphology is obtained by micro cold pressing. The depth of groove is related to DY and DZ. When DZ is fixed, depth of groove is smaller when DY is 0.05mm than that when DY is 0.1mm. Under fixed DY, the depth of groove increases with the increase of DZ. Surface quality (including surface roughness, roughness and surface morphology) affects friction coefficient and wear rate. Reasonable surface quality not only decreases friction coefficient but also decreases wear rate. Friction coefficient can be reduced by 10% while wear rate can be reduced by 69.76%.

In the traditional model of fault diagnosis, neural network classification requires high demand for the number and completeness of samples with a problem cannot be overcome- -"the curse of dimensionality". While the actual bearing failure is a typical case of small sample with few samples and the number of different types of samples is asymmetrical and even not complete. And the pattern classification effects of the support rector machine in case of small sample are better. Therefore, according to the above comparative analysis, combined with the character of small samples of actual bearing failure mode, this paper selects to build classification model based on the support vector machines, and after researching, the model proved to be feasible.

In this paper, we formulate a least squares version of the one-class support vector fuzzy machine (LS one-class SVFM) which is combined with the fuzzy set theory. The parameters in the proposed algorithm, such as weight vector and bias term, are fuzzy numbers. Our model only needs to solve a system of linear equations, instead of a complex quadratic programming problem (QPP) solved in one-class SVFM. Our experiments on publicly available datasets indicate that our model has comparable classification accuracy to that of the one-class SVFM but with remarkably less computational time.

The ASIC for control of the digital signal is progressing in the development of the avionics of the aircraft. In addition, the proportion used the ASIC in the industries is increasing continuously. However, it occurs the difficult problems of the maintenance of ASIC fault due to the maintenance company’s bankrupt, equipment’s aging, test equipment exchange and test requirement document’s absence in the case of avionics systems. Therefor it will be expensive repair costs. To solve these problems, we proposed the method to testing the analog board with ASIC and without the TRD. In this paper, we proposed the Dynamic Pattern test method which created the TRD based on analyzed logic data extracted from ASIC and diagnosed on the ASIC circuits at the point of level of gate. We could identify the 17 pattern from tests, and figure out faults in 16 addresses. According to the experiment for target board applied with proposed methods, it is possible to diagnose fault for abnormal computerized chip, ASIC, by utilizing test unit board. We’ve also obtained the excellent performance for fault detection.

The aerodynamic performance of wind turbine airfoils was an important foundation for the aerodynamic design and the performance analysis of the wind turbine. In this paper, fluent aerodynamics performance of a wind turbine airfoil S414 is simulated based on CFD. Its pressure coefficient with different angles of attack was obtained. The numerical results are compared with the experimental data, which proves the simulation data of Spalart-Allmaras equation is fit for airfoil S414. The theoretical foundation is established for three-dimensional flow simulation of airfoil in the future. Besides, adopting Spalart-Allmaras turbulence models can improve the predicting results for aerodynamic performance. The proposed method provides an effective way to predict the aerodynamic characteristics of wind turbine. This study provides quick and valid numerical simulation methods for wind turbine airfoil aerodynamic designing and possesses higher utility value in engineering.

Over the last decade there has been an obvious reduction in the number of non-fatal and fatal accidents involving the worldwide commercial jet airplane fleet. While most runway excursions are relatively minor with no serious injuries or airplane damage occurring, they have the potential to pose a serious risk to public safety and infrastructure. Preventive risk controls are the most important way to reduce the frequency and consequences of runway excursions. This research was based on a comprehensive database of Runway Safety Areas-related accidents. It was matched by a representative sample of normal operation data, such that the exposure to a range of flight-operational and meteorological risk factors between accidents and normal flights could be compared. This study focused on the risk frequency about a case airport which does not meet the 'Runway end safety area' requirement of ICAO Standards and Recommended Practices and Korean standards and used 'RSA risk model' for estimating the risk frequency. As results of this study, risk frequency of the runway end safety areas in the case airport is higher than that of 'Runway end safety area' requirement of ICAO SARPs and Korean standards. It means that alternatives for risk frequency mitigation to a level as low as reasonably practicable is required in the case airport.

The wave energy converting system (WEC) can convert the unstable wave energy into stable electric power. In this paper, the new WEC which is mainly composed of three hydraulic circuits viz, the commutation, decompression and speed regulation circuit. It is controlled by various electronic valves. A series of experimentations were done to investigate its static and dynamic characteristics under the condition of variable load and variable flow rate, and its influence on the grid was analyzed as well. The experimental result shows that when the flow rate of the system which is controlled by the electro-hydraulic proportional flow control valve varies, the accumulator conserves part of the hydraulic energy and consequently the output power decreases. The revolving speed and working pressure show the different change trend in the response to the variation of the flow rate. However, when the load varies, the revolving speed of the hydraulic motor varies marginally. In the case of identical load change, the amplitude of variation is not the same at different revolving speed. Because of adopting the proportional flow control valve, the new WEC can be regarded as a non-differential control system which may cause the oscillation of the active power. To avoid this, this paper suggests using the variable-speed constant-frequency device or electrical governor.

This paper presents a simple digital D1S lamp system with a power structure of flyback converter and full-bridge inverter using a low-cost 8-bit one-chip microprocessor to optimize the total system size and minimize implementation cost. The D1S lamp is a high intensity discharge lamp used for the headlight lamp of advanced cars. D1S lamp driver in the proposed system can generate high voltage to ignite the lamp. It can effectively control the power required to drive the lamp after the ignition. The proposed driver is consisted of an igniter, a DC-DC converter, a DC-AC inverter, and a control circuit. The DC-DC converter utilizes the flyback converter topology to minimize its component number. It is utilized to generate high ignition voltage of the D1S lamp. When the operation of the proposed system arrives in a steady state, the driver controls the lamp with AC current using the DC-AC inverter. In this paper, the operation principle of the proposed driver is described in details and the operation principle related to the igniter is explained briefly. Experimental results demonstrated that the proposed system had good performance for the D1S lamp.

This study suggests RESTful web service and push service based management of BLE beacon network that consists of beacons, gateways and manager. For management information exchange, RESTful web service based RBNM (RESTful web service for BLE beacon Network Management)-API was defined, and using RESTClient, the validity of the defined RBNM-API was verified. By implementing the BLE beacon network management system as a laboratory model, manager processing time was measured and analyzed according to database access methods and JSON parser types to process beacon configuration information. Websocket, web’s push service technology was compared with existing polling and Comet technologies in terms of waiting time of event notification. Event notifications toward smart devices tested and notification delays were measured with GCM3.0-API and RBNM-API.

The control system for correction projectile is a strongly nonlinear and time-varying complicated system. Conventional PID controller has been widely used in the control system of ammunition. But it cannot achieve highly control effect because of the complexity and uncertainty of system model. With fuzzy control and fractional order control theory, this paper puts forward a fuzzy fractional order controller through taking correction projectile as controlled object. On one hand, self-adaptive adjustment to the parameters can be realized because fuzzy control is not dependent on the control model; on the other hand, better control effect can be brought by using fractional order controller to control integer order system. Simulation results show that the the fuzzy fractional order PIλDμ controller demonstrates the better time domain response characteristics compared with the fractional order PIλDμcontroller and the conventional PID controller, and can be used to improve the robustness of the system in the correction projectile system control.

In this paper, we proposed a new dimming control scheme by using direct sequence spreading coding (DSSC) scheme in visible light communication (VLC). VLC systems using LED lighting can provide illumination functions and communication services at the same time. In order to provide simultaneous illumination and communication services, dimming control should be considered. Dimming control means that LED lighting should maintain a constant brightness in accordance with user requirements while communication services are offered. In IEEE 802.15.7 VLC standard, on-off keying (OOK) and variable pulse position modulation (VPPM) are defined as pulse modulation schemes for dimming control. In particular, 4B/6B, 8B/10B block coding and Manchester coding schemes have been proposed for stable dimming control in OOK. However, in such a case, stable dimming control is possible although the communication performance is degraded. In order to solve those problems, we propose a VLC system based on OOK modulation with DSSC. The proposed system can simultaneously stabilize dimming control and improve communication performance by obtaining spread diversity gain. The simulation results show that the proposed system provides superior dimming and BER performances compared to conventional dimming modulation schemes.

In this paper, a method for estimating the image Jacobi matrix in an uncalibrated binocular stereo visual servoing system is presented. The method is based on the singular value decomposition aided Cubature Kalman filter with neural network (NNSVDCKF). First of all, the parameter expression of image Jacobi matrix is obtained by analysis of model of eye-in-hand binocular vision. Then, in the case of the unknown camera parameters, the singular value decomposition aided Cubature Kalman filter (SVDCKF) algorithm is used to estimate the Jacobi matrix, and the neural network (NN) as the noise compensator which compensates the process noise and measurement noise. To demonstrate the effectiveness and practicality of the proposed algorithm, an uncalibrated binocular visual servoing control system based on 6DOF robot PUMA560 is established. Finally, the three algorithms of NNSVDCKF, SVDCKF, and standard Kalman filter (KF) are compared in the uncalibrated servoing system. The simulation results show that the NNSVDCKF algorithm improves the dynamic performance of the system greatly, and has robustness to the constraint in field-of-view (FOV) of the camera.