bluuebunny/crossref_metadata_2025 huggingface dataset:
The Potential Predictors of Motor Performance Outcomes after Rehabilitation for Patients with Stroke
Authors: Lee Jiann Der , Chang Tzyh Chyang , Yang Shih Ting , Huang Chung Hsien , Wu Ching Yi
Published: March 2013

The identification of potential predictors for motor outcome after rehabilitation helps underscore the factors that may affect treatment outcomes and target individuals who benefit the most from the therapy. In this study, we addressed and utilized a classifier to identify the potential predictors for motor performance outcome for patients with stroke after rehabilitation. The potential predictors selected and used by different assessments in this study were age, sex, time since stroke, education, neurologic status, and the movement performance of the upper extremity. This study aimed to identify predictors of motor performance outcomes after rehabilitation for stroke patients. The PSO-SVM was chosen in this study to find the predictor of motor function for clients with stroke. The potential predictors for motor outcome after rehabilitation were motor ability assessment of the Fugl-Meyer Assessment (FMA) and the Functional Independence Measure (FIM). This study is to investigate the potential demographic and clinical characteristics of stroke that can serve to predict rehabilitation outcomes in motor performance.
The Encoding Analysis of Brainwave for Direction Recognition
Authors: Kao Fu Chien , Wang Shin Ping R. , Hung Chia Chun , Chen Chih Chia , Du Jyun Yi
Published: March 2013

This research discusses about recognizing direction by brainwave characteristic frequency band in the digital coding mode. The experiences proceeded by catching brainwave signals of human vision while sensing the test interfaces of graphics and words representing direction by brainwave sensor. To compile the related samples of energies from brainwave frequency band and times of appearances, then establish the directions which stand for left-turn, right-turn, forward and backward of brainwave characteristics frequency band and its digital coding modes. Studies are to derive and analyze brainwave signals from testing interfaces of different color combinations of patterns and words, and after that build the digital coding combinations of brainwave characteristics frequency band. This research is to analyze and discuss every kind of brainwave frequency band characteristics while subjects recognize the directions; moreover, to confer the topics such as analyzing the influences of different designs of pattern and word testing interfaces made in brainwave of recognizing directions in the view of Cognitive Neuroscience as well as defining if testing interfaces of color designs effect the brain wave signals while judging directions from human vision.
The Application of LSA in TCM Syndromes Classification
Authors: Gan Yan Fang , Ni Zi Wei , Lin Fan
Published: March 2013

The description of syndromes and symptoms in traditional Chinese medicine (TCM) is extremely complicated. And how to diagnose the patient's syndrome in a better way is the primary objective of clinical health care workers all the time. It was a good attempt to diagnose patient's syndrome by combining Latent Semantic Analysis and the feature of TCM knowledge----both syndromes and organs have the same clinical manifestation collection that are symptoms. In this paper, correlative degrees would be computed and sorted in a certain latent semantic space which was constructed by syndromes and organs . According to the result of correlative degrees computing, the classifying could be done by choosing the highest correlative degree as the belonging class. The experimental results show that this method performs quite well.
Study of Quality Evaluation Indexes in Filtered ECG Signal
Authors: Zheng Gang , Sun Ming Li , Gu Yuan
Published: March 2013

Electrocardiogram (ECG) is a kind of weak signal. It was disturbed by surrounding factors, even by patient him/herself. It was happened mostly in portable device. Filtering is an usual step in ECG signal processing. Therefore, the quality evaluation of ECG signal became necessary. In the paper, some indexes were proposed to evaluate the quality of filtered ECG signal. The definition and recommended values or limits of the indexes were discussed. The indexes covered from the aspects of signal procession and clinical diagnosis meanings. They were Signal-to Noise Ratio (SNR), Autocorrelation coefficient (AC), Transformation Ratio (StTR) and Voltage Amplitude Change (StTV) of ECG ST Segment. Median, Wavelet, and Morphology filters were selected in the experiments. From the experiment results, Wavelet performs best in controlling attenuation, but it distorted ST segment the most, both in shape and in its voltage amplitude. The shape change ratio may reach 25%, compare to 17% of median and 14% of morphology, and those filters were acceptable clinical evaluation. It was proved that the indexes can become the potential standard in quality evaluation in ECG signal filtering process.
Nanocrystalline Diamond Particles Prepared by High-Energy Ball Milling Method
Authors: Lin Chii Ruey , Wei Da Hua , Dao Minh Khoa Ben , Chung Ren Jei , Chang Ming Hong
Published: March 2013

In this present work, nanodiamond (ND) particles were successfully prepared from commercial micron diamond powder at room temperature by high energy ball milling process using an oscillatory mill (SPEX8000). The size reduction and structural evolutions of the milled samples were investigated as a function of the milling time by means of X-ray diffraction, and field emission scanning electron microscopy. The line broadening technique was used to determine the crystallite size and lattice strain. After 40 h of milling, obtained ND particles possessed uniform shape and 25 nm of average particle size. Also, energy dispersive X-ray results revealed the high purity of ND and demonstrated that the purification process using harsh acid mixture were effective to remove metal and non-diamond carbon impurities produced in milling stage. All results propose a scalable method to preparation ND particles as well as nanocrystalline materials.
Solitary Pulmonary Nodule Detection on Thoracic CT Images through Object Continuity Analyses
Authors: Lee Seok Lyong , Cho Du Hyung
Published: March 2013

Lung cancer has been a leading cause of death in the world, and it is known that prompt diagnosis and treatment may be the only chance for curing the cancer. Early lung cancer often presents as a solitary pulmonary nodule (SPN) and the timely detection of it is critical to save life from cancer death. In this paper, we present an effective method to detect SPNs on thoracic CT images through object continuity analyses. First, a lung region is segmented from other chest organs using morphological operations and thresholding techniques, and an initial set of candidate SPNs are identified. To represent the SPN, we define the rotation-invariant bounding rectangle (riBR) that tightly encloses an object. The subsequent processing is based on the riBR instead of an object itself to avoid the processing overhead. Next, non-nodule objects are pruned using geometric features and the object continuity analyses on a series of CT slice images. Through the analyses, cylinder-shaped non-nodule objects such as blood vessels and bronchia are eliminated and a final set of candidate SPNs is obtained. An experimental result shows that the proposed method works effectively in detecting SPNs. The application context addressed in this study is the pulmonary nodule detection but other application areas also can benefit.
Obstructive Sleep Apnea Identification by Heart Rate Features Derived from Intrinsic Mode Function
Authors: Chang Kang Ming , Chen Sih Huei
Published: March 2013

Obstructive sleep apnea (OSA) is one of the most important sleep disorders. The gold standard diagnosis of OSA is overnight PSG examination that is time-consuming and labor intensive. Overnight ECG signal was developed to examine OSA, with easy implementation and portable equipment. There were various ECG derived features used for OSA identification, in this study, intrinsic mode function (IMF) was developed. IMF is a byproduct of Hilbert-Huang transform. IMF decompose original signal into various sub components, due to its complexity. In this study, some novel IMF derived features were used to examine the OSA duration measured from ECG signal, compared with traditional HRV features.
The Head Shadow Phenomenon Affected by Sound Source: In Vitro Measurement
Authors: Yu Jen Fang , Chen Yen Sheng
Published: March 2013

This study focuses on establishing an in-vitro sound filed measurement system in order to investigate the effect of sound source angle and frequency on the head shadow effect (HSE). The study used sound stimuli at frequencies of 125 Hz, 250 Hz, 500 Hz, 750 Hz, 1 kHz, 2 kHz, 3 kHz, 4 kHz, 5 kHz, 6 kHz, 7 kHz, 8 kHz, and with sound source positioning at angles of 0, 30, 45, 60 and 90 degrees. It evaluated the effect these frequencies and positioning combinations had on the HSE. When the sound source was positioned at 90 degrees to the ear, this study found that the HSE not only existed at the frequencies of 4 kHz to 6 kHz, but also the HSE could be happened at 3 kHz, 7 kHz and 8 kHz. In addition, a significant influence on HSE was also demonstrated when the sound stimulus was positioned at 45 degrees to the ear, with a frequency range between 3 kHz~8 kHz. As well as considering head and ear anatomy and the head shadow effect when selecting and fitting hearing aids, it is also necessary to consider adjustment to account for angular sound sources at different sound frequencies.
A Low Power CMOS Temperature Sensor
Authors: Yi Shu Chung
Published: March 2013

This Paper Proposed a Low-power Smart Temperature Sensor. the Sensor Consisted of a PTAT Circuit, and a Ring Oscillator. the Current of the PTAT Circuit Was Used to Drive the Ring Oscillator which Generates a Temperature Related Signal. the Sensor Was Implemented by the TSMC CMOS 0.35 µm 2P4M Digital Process. the Core Aµµrea Is only 1105.59 µm2. the Power Consumption Is aboutµ 159.15 nw. the Linearity between the Output Frequency and Temperature Is Marked by R-square Rule. the Value of the Linearity Is 0.991 during the Temperature Range. the Proposed Sensor Required only One Supply Voltage. the Core Area Was Small. Therefore, the Sensor Was Suitable for Embedded in any Circuit that Required Temperature Monitoring.
Nonlinear Dynamic Characteristics of Giant Magnetostrictive Nanofilm-SMA Composite Beam in Axial Stochastic Excitation
Authors: Zhu Zhi Wen , Guo Wei , Xu Jia
Published: March 2013

In this paper, nonlinear dynamic characteristics of giant magnetostructive nanofilm-shape memory alloy (SMA) composite beam in axial stochastic excitation were studied. Von del Pol nonlinear difference item was introduced to interpret the hysteresis phenomenon of the strain-stress curve of SMA, and the hysteretic nonlinear dynamic model of giant magnetostructive nanofilm-SMA composite beam in axial stochastic excitation was developed. The steady-state probability density function and the joint probability density function of the system were obtained in quasi-nonintegrable Hamiltonian system theory. The result of simulation shows that the stability of the trivial solution varies with bifurcation parameter, and stochastic Hopf bifurcation appears in the process. The result is helpful to stochastic bifurcation control to giant magnetostructive nanofilm-SMA composite beam.
A Real-Time Center of Gravity Trajectory Generation of a Biped Humanoid under Variable Reference ZMP Trajectory
Authors: Park Ill Woo , Cho Baek Kyu , Kim Jung Yup
Published: March 2013

This paper describes a method for generating a center of gravity trajectory of a biped humanoid robot under variable reference ZMP trajectory. A simple inverted pendulum model (SIPM) is used to calculate a center of gravity (CoG) trajectory from a reference zero moment point (ZMP) trajectory with an analytic form, which is based on the Fourier series. Fundamentally, we used a time segmentation based approach. For each segment, we defined its duration and boundary conditions, which are the key parameters of ZMP trajectory design. After designing the ZMP trajectory in each segment, we can automatically calculate the CoG trajectory by matching the boundary conditions and by calculating the coefficients between the time segments. The reference ZMP trajectory can be changed by updating the boundary conditions during walking. We successfully verified the proposed method through full-body dynamic simulations with variable step length.
Application of Magneto Rheological Damper on Semi-Active Suspension System
Authors: Shiao Yao Jung , Nguyen Quang Anh , Lai Chun Chi
Published: March 2013

Automotive industry is growing widely and rapidly by the involving of multi-fields not only mechanical engineering but also electrical and electronic engineering, material and more. As a key system in vehicles, suspension system and its control have been studied for a long time. A well-controlled suspension system provides high vehicle handling, good drivability and high comfort for passengers, and good isolation from road noise and vibration. To enhance comfort and handling of light-weight vehicles, semi-active suspension system is considered and proposed by numbers of papers. A semi-active suspension features small system space, low complexity and easy maintenance. Therefore, it is suitable for small compact car body known as light vehicles. This paper focuses on the analysis and control of a semi-active suspension for light-weight vehicles. Models of a quarter-car suspension with air spring and magneto rheological damper were built. Because components in the system involve nonlinear dynamic characteristics, a self-tuning Fuzzy logic controller was designed. Simulation results showed that the designed suspension system with its controller had good performance in vibration suppression.
Control and Response Characteristics of a Mixed Mode MR Damper for a Multi-Story Structure
Authors: Sung Kum Gil
Published: March 2013

This paper presents vibration control responses of a multi-story structure installed with a semi-active magneto-rheological(MR) damper. As a first step, performance characteristics of three different working modes for MR fluid are compared and the mixed mode type of MR damper is chosen as an optimal candidate for the vibration control of the multi-story structure. An appropriate size of the mixed mode MR damper is devised and manufactured on the basis of the field-dependent Bingham model of the MR fluid which is commercially available. The damping force of the mixed mode MR damper is evaluated with respect to the excitation frequency at various magnetic fields. After formulating the governing equation of motion for the small scaled three-story structure associated with the MR damper, the linear quadratic regulator(LQR) controller to effectively suppress unwanted structural vibrations is designed by imposing semi-active actuating conditions. The control algorithm is then empirically implemented under earthquake conditions and the control responses of the horizontal relative displacement and acceleration are evaluated in time and frequency domains through computer simulations.
Cross-Coupling Controller for Five Degree-of-Freedom Coplanar Nanostage
Authors: Liu Van Tsai
Published: March 2013

The proposed approach is to design a tracking controller for five degree-of-freedom coplanar nanostage which can provide high precision applications. This study propose a viscoelastic creep model, it was modeled as a series connection of springs and dampers to describe the creep effect. Then, utilize a PI controller using Taguchi method to search the optimization parameters to suppress the tracking error. Finally, a cross-coupling control scheme is proposed to eliminate the contour error which is typical in dual-axes tracking control problem. The developed approaches are numerically and experimentally verified which demonstrate performance and applicability.
Design and Experimental Results of a Quad-Rotor Control System
Authors: Kang Tae Sam , Lee Gi Gun , Kim Jung Hwan
Published: March 2013

Multi-rotor is one of the emerging Unmanned Aerial Vehicle platforms. This paper covers the design, fabrication, modeling and testing of a quad-rotor control system. To take into account the salient nonlinearities, a model with six degrees of freedom nonlinear dynamics and some linear approximation of the aerodynamic part are used when extracting a linear model and designing a attitude controller. We obtained a linear model from experimental data using system identification method and developed attitude control algorithm. The control algorithm was realized using an on a board microprocessor and verified through experiment in real environment.
Design and Performance Evaluation of Modular Electro-Mechanical Actuator
Authors: Park Min Kyu , Go Seok Jo , Lee Young Jin , Sung Kum Gil
Published: March 2013

This article is dealing with a modular electro-mechanical actuator (EMA). Modular EMA consists of harmonic reducer, servo motor, electric brake, multi-turns absolute encoder, drive, network board. There are various modular EMAs in the market. Most of them are used for toys and educational device. In this research, we are more focused on an industrial high power (400W) modular EMA. All of components are designed and fabricated as hollow shaft type module for applying an industrial robotic system in the future. The robot which is linked to the modular EMA is easily able to assemble and disassemble or reconfigure it. We try to implement a modular EMA and this tries to be verified through an experiment.
Design for a Novel Electromagnetic Valve for Camless SI Engines
Authors: Dat Ly Vinh , Shiao Yao Jung , Huang Chin Hau
Published: March 2013

Some previous studies have demonstrated that variable valve timing can effectively enhance engine performance, as well as significantly reduce fuel consumption and emission for SI engines. Use of electromagnetic valve train (EMV) in an engine allows valve timings to be variably controlled at different operating conditions. By this way, an EMV engine is superior to an engine with conventional camshaft-based valve train in improving engine efficiency. In this paper, a novel EMV, which uses permanent and electromagnet together, has been proposed. Improvements in structure, actuating method and optimal parameters for this EMV have brought many advantages about low actuating power, easy actuation and fast response, etc. The results show that this EMV achieves 15% volume reduction and 20% holding force enhancement by special armature design. With the aids of permanent magnet and valve releasing strategies, this novel EMV only needs small EMV actuating power compared with conventional EMV.
Development of a Web-Based Virtual Five-Axis Milling Toolpath Simulation System
Authors: Kao Yung Chou , Chen Mau Sheng , Chiu Tzu Hao
Published: March 2013

Virtual machine tool has been used in the toolpath simulation of a real machine tool with very promising achievement in teaching assistance. However, a five-axis milling machine is generally very expensive in comparison with traditional three-axis milling machine in its configuration. This is mostly resulted from the addition of two more rotational axes in five-axis machine. This paper focuses on the development of a Web-based five-axis milling machining toolpath simulation system so as to facilitate the comprehensive understanding of students and to ease the explanation of operations. A user can access the developed system through the web browsers such as the Microsoft Internet Explorer and Google Chrome as long as the Java Runtime Environment and OpenGL are installed. Three general configurations of five-axis milling machine tool have been implemented including Head-Head, Head-Table, and Table-Table. Furthermore, five-axis post-processing is generally a bottleneck in the popularization of toolpath simulation. An intelligent distributed agent-based post-processor has been integrated in this system. For example, an APT file created by the usage of Catia CAD/CAM software according to a five-axis toolpath could be post-processed by the developed system for the generation of a five-axis NC program. This NC program could then be simulated in the proposed system. The developed system has been successfully implemented and shown very promising application in the understanding of five-axis milling operation.
Oxidation Resistance and Corrosion Resistance of AlTiCrON Multilayered Coatings on AISI M2 Tool Steel
Authors: Ho Wei Yu , Hsu Cheng Hsun , Yang Zhong Shen , Shen Li Wei , Ho Woei Yun
Published: March 2013

This study utilized the reaction of O2/N2 gases and Al0.67Ti0.33/Cr (99.9%) dual targets to synthesize (Ti,Al)ON/CrON multilayered coatings on AISI M2 steel by cathodic arc deposition system. Thermal stability and corrosion resistance of the multilayered coatings for aluminum die casting applications, along with coating structure were investigated. The results showed that the structure of multilayered coatings was a B1 NaCl type. The formation of oxide phases by introducing oxygen to react with Al, Cr, and Ti elements was confirmed by XPS. The thermal stability of oxygen-doped AlTiN/CrN coatings was higher than that of one without oxygen. After the immersion tests in Al-alloy melt, the oxygen-doped AlTiN/CrN coatings deposited at the O2/N2 ratio value of 0.3 had the best improvement on the corrosion resistance among all the coated specimens.
Evaluation of Analytical and Finite Element Modeling on Coupled Field Dynamics of Piezoelectric Cantilever Bimorph Harvester
Authors: Zhang Long , Williams Keith A. , Xie Zheng Chao
Published: March 2013

As the portable electronics and wireless sensors continue to be minimized in size and power consumption, the energy harvesting from the surrounding environment has become a potential major or supplementary power source for those devices. As an energy harvesting option for converting the mechanical vibrations to the electrical energy, the structure-electricity field coupled piezoelectric materials have relatively high conversion efficiency, light weight and small size, making them preferable for wireless sensor networks and portable electronics. In this paper, the modeling work on coupled field dynamics of the piezoelectric cantilevered bimorph (PCB) energy harvester is presented, in terms of structure tip displacement and open-circuit electrical potential generated through harmonic excitation. First, a single degree of freedom (SDOF) analytical model is presented for predicting the tip displacement of the PCB structure, and then a finite element (FE) model is created to simulate the tip displacement and open-circuit voltage of the PCB structure. Then, both the analytical and finite element models are compared against the laboratory experimental results. The comparison shows that the FE model has a better agreement with the experimental result than the analytical model. Based on the evaluation, these two models could be adopted as design tools in different cases.
Fast Development of Flexible Motor Control System with Model Based Design
Authors: Kong Fan Feng , Hu Jian , Tao Tao , Mei Xue Song , Zhang Ying Qing
Published: March 2013

In this paper, model based design was introduced for fast developing the flexible motor control system. Unification of synchronous and asynchronous motors was proposed as they have same control framework. Based on the combinatorial study of motor control system’s inputs, outputs and state variables, a flexible motor control system was established that for synchronous and asynchronous motors, variety of control algorithms can switch, expand to and combine with each other freely. Building the finite element model of the motor with Ansoft Maxwell, the parameters and the electromagnetic characteristics of the motor have been obtained by finite element analysis. With the PID parameter auto-tuning method, the result of the system simulation proves the correctness of the control algorithm. After continuous testing and validation, the simulation model was changed into fixed-point model according to the embedded processor. Combining underlying drive with automatic code generation, the software of the motor control system was achieved rapidly. A servo driver and a motor servo performance test-bed were designed to test the automatically generated code and control algorithm. The experimental results show that a flexible motor control system with good servo performance has been achieved rapidly with model based design.
Improving the Accuracy of Depth Estimation in Binocular Vision for Robotic Applications
Authors: Chen Kuan Yu , Chien Cheng Chin , Tseng Chien Te
Published: March 2013

Binocular vision or stereo vision for extraction of three-dimensional information from stereo images has been widely used in many applications like robot navigation, recovering the three-dimensional structure of a scene, and optical inspection systems. More recently, the majority of research in binocular vision has focused on the establishment of stereo matching. However, to date, there has been relatively little research conducted on the effect of computational models of binocular vision with variable focal length of lens. In this paper, a modified computational model of binocular vision is presented to develop a new depth estimation algorithm with no effect of changes in focal length. This method provides an obvious advantage in accuracy of depth estimation by reducing the effect of changing the lens focal length. The experimental results show that the proposed depth estimation method in binocular vision provides better accuracy than conventional method. Finally, we apply the new depth estimation method to a stereo-vision-based automatic docking system for a mobile robot to verify its accuracy.
Passivity-Based Parameter Estimation and Position Control of Induction Motors via Composite Adaptation
Authors: Chen Jenn Yih
Published: March 2013

This paper proposes the parameters estimation and position control of an induction motor drive by using the composite adaptation scheme. First, in the rotor reference frame, the input-output linearization theory was employed to decouple the mechanical rotor position and the rotor flux amplitude at the transient state. An open-loop current model rotor flux observer was utilized for estimating the flux, and then the adaptive laws for estimating the rotor resistance, moment of inertia, viscous friction coefficient, and load torque. The passive properties of the flux observer, rotor resistance estimator, and composite adaptive position controller were analyzed based on the passivity theorem. According to the properties, the overall position control system was proved to be globally stable without using Lyapunov-type arguments. Experimental results are finally provided to show that the proposed method is robust to variations of the motor mechanical parameters, rotor resistance, and load torque disturbances. Moreover, good position tracking response and characteristics on parameter estimation can be achieved.
Quasi-Static Step Number Determination Method of a Quadruped in Step Crossing
Authors: Park Sung Ho , Hong Dong Pyo
Published: March 2013

Legged living creatures can move on any kinds of terrain with good adaptability. They read the terrain conditions and repeat inherent or acquired obstacle crossing sequences, which can be imitated mechanically for the design of a Quadruped. For the prototype model and the step, four corner distances are determined according to the desired body angle and the continuous locomotion sequences are determined. Also, the requirements to satisfy three conditions for step-down are introduced, which makes it possible to determine the exact number of steps in the second phase of step-down. Since step-up is the reverse of step-down, all the governing parameters are the same and the locomotion sequences of step-down are also the reverse of step-up, except for the case of walking-down by gravity. The dimensions of a suggested quadruped are used to calculate the crossing performance for the purpose of comparison.
Realization of a Motion Control System for Wafer-Handling Robot Using SoPC Technology
Authors: Chou Hsin Hung , Kung Ying Shieh , Tsui Tai Wei , Cheng Stone
Published: March 2013

The novel FPGA (Field Programmable Gate Arrays) can embed a processor to be an SoPC (System-on-a-Programmable-Chip) environment which allows user to design the applications by mixing hardware and software. Therefore, a motion control system of wafer-handling robot based on the SoPC technology is presented in this paper. In FPGA, it is consists of two modules. The first module is Nios II processor which is used to realize the motion trajectory planning and three-axis position/speed controllers by software. The program developed in Nios II processor uses C language. The second module is presented to implement three-axis current vector controllers by hardware, and VHDL (VHSIC Hardware Description Language) is applied to describe the controller behavior. Therefore, a fully digital motion controller for wafer-handling robot, such as three current vector controllers, three position/speed controller and one trajectory planning are all can implemented by a single FPGA chip. Finally, an experimental system constructed by an FPGA experimental board, one three-DOF wafer-handling robot, and three inverters is set up to demonstrate the correctness and effectiveness of the proposed SoPC-based motion control system of wafer-handling robot.
Real-Time Navigation for a Humanoid Robot Using Particle Filter
Authors: Baltes Jacky , Cheng Chi Tai , Lau Meng Cheng , Espínola Andrés
Published: March 2013

This paper presents a practical real-time visual navigation system, including a vision system, a particle filter (PF) based localization system, and a path planning system, for humanoid robots in an indoor environment. A neural network (NN) converter system is used to solve the image distortion problem. The monocular vision system detects objects of interest in the scene, calculating their position in the image, and converting the position in the image to real world coordinates. The PF localization system estimates the current position by the robot’s motion model and corrects the estimated position by using feedback from the data gathered by the vision system. The path planning system determines the next motion based on the result of the localization system. This paper uses a tree-like path planning method which not only guides the robot to the destination but also avoids obstacles at the same time. The navigation method allows a user to assign several different target destinations to the robot simultaneously. The proposed method is implemented on a humanoid robot “ROBOTIS DARwIn-OP”, an open platform humanoid robot. The effectiveness of the system is demonstrated in an empirical evaluation.
Robust Adaptive Trajectory Control for an Omnidirectional Vehicle
Authors: Yang Ya Chao , Cheng Chi Cheng , Chen Chin Yin
Published: March 2013

In this paper, a robust adaptive control strategy is proposed for trajectory control of an omnidirectional vehicle with three omni-wheels, which have the ability to move simultaneously with independently rotational motion. Actuators of the omnidirectional vehicle contain uncertainties and their parameters are unknown. By the Lyapunov stability, the asymptotic tracking performance can be assured. The proposed control scheme is demonstrated by actual tracking experiments using the omnidirectional vehicle system. Experimental results showed promising tracking performance for the proposed method as compared to traditional sliding mode controller.
Synthesis of Two-Degree-of-Freedom Rotational Decoupled Manipulators of a 2R-Type Branch
Authors: Zeng Da Xing , Lu Wen Juan , Zhang Li Jie , Zhang Yi Tong
Published: March 2013

Strong coupling is one of the prominent features of the general parallel mechanisms(Par. Mec.), which has led to difficulty in the trajectory planning and precision control. To solve this problem, the designing of motion decoupled parallel mechanisms(Dec. Par. Mec.) has become a hot topic. This paper, based on the work achieved in our pre-papers, is to make an improvement on the criterion for a branch type synthesis of the rotational decoupled parallel mechanisms(Rot. Dec. Par. Mec.), which ensures the decoupling of the rotations in each limb. This paper focuses on a type synthesis of the decoupled parallel mechanisms with two degree of freedoms (DOFs). Decoupled parallel manipulators with two parallel kinematic chains, one of which is of type 2R(R represents rotation), are taken into consideration in this paper. A large number of novel decoupled architectures are already obtained, some of which have got an application for a China Patent. What has been done in this paper is carried out by means of the screw theory, which has effectively avoided complex equations by synthesis.
Properties of RF Magnetron Sputtered Sr0.4Ba0.6Nb1.85Ta0.15O6 Thin Films
Authors: Yang Cheng Fu , Tzou Wen Cheng
Published: March 2013

Sr0.4Ba0.6Nb1.85Ta0.15O6 (SBNT) ceramic was used as a target and SBNT thin films were deposited at room temperature. After deposition, the SBN thin films were annealed in conventional furnace (CFA) and in an oxygen atmosphere for 1h by changing the temperature from 700oC to 900oC. The thicknesses of the SBN thin films were calculated by SEM and they were about 450nm independent on the annealing temperature. From the XRD patterns, the as-deposited SBNT thin films displayed amorphous phase, whereas as CFA-treatment was used, the SBNT thin films displayed smooth surfaces. The grain sizes also increased with increasing CFA-treated temperature. In addition, the remanent polarization and saturation polarization increased and coercive field decreased with increasing CFA-treated temperature. Finally, the lnJ-E1/2 curves of the SBNT thin films was developed to find that the linear variations of leakage current densities correspond either to the Schottky emission mechanism or to the Poole-Frenkel emission mechanism.
System Identification and Robust Control of a Pneumatic Muscle Actuator System
Authors: Lin Liu Hsu , Yen Jai Yush , Wang Fu Cheng
Published: March 2013

This paper describes the application of system identification techniques and robust control strategies to a pneumatic muscle actuator system. Due to the inherent nonlinear and time-varying characteristics of this system, it is difficult to achieve excellent performance using conventional control methods. Therefore, we apply identification techniques to model the system as linear transfer functions and regard the un-modeled dynamics as system uncertainties. Because robust control is well-known for its capability in dealing with system uncertainties, we then apply robust control strategies to guarantee system stability and performance for the system. This work is carried out in three parts. First, the pneumatic muscle actuator system was modeled as linear transfer functions. Second, robust control theorem were utilized to design a Hinf robust controller to deal with system uncertainties and performance requirements. Finally, the designed controller was implemented for experimental verifications and compared with a conventional PID controller. From the experimental results, the proposed Hinf robust controller is deemed effective.
The Effect of Thermal Contact Resistance on Heat Management in a Shuttling PCR System
Authors: Chen Jyh Jian , Chen Wei Hua , Shie Yi Shiang
Published: March 2013

A novel shuttling polymerase chain reaction (PCR) system is assembled to make temperature uniform in the reaction chamber. The chamber is oscillated by a servo motor and contacted with three different isothermal zones to complete several thermal cycles. The home-made computer code is utilized to investigate the influences of operational parameters on the temperature inside the chamber. Numerical results show that the contact resistances between the heating blocks and the reaction chamber dominate the temperatures inside the PCR chamber. In this work a PCR system that is composed of the PID controller, the moving stage, three aluminum blocks for three different isothermal zones and a reaction chamber is also developed. Experimental results demonstrated that the stability of this shuttling PCR system is confirmed. And results show that DNA templates provided with the yT&A® cloning vector are amplified successfully in this PCR system.
The Fault Tolerant Output Selector Based on Fault-Detection Considering Realistic Fault Modes for Pedal Simulator of Brake-by-Wire System
Authors: Li Jian Hu , Park Man Bok , Kim Hun Mo
Published: March 2013

A brake pedal simulator in a Brake-by-Wire system is studied for fault tolerant control of the brake pedal signals. This study is conducted for the pedal simulator installed with a sensor that generates two analogue signals. Several realistic fault modes recognized by automotive experts have been analyzed. To solve the fault modes, we propose a fault tolerant output selector that can handle transient, intermittent, or permanent faults. The fault tolerant output selector, based on a fault detection algorithm, uses the BLS(brake light switch) signal and the Acc(acceleration pedal) signal to find faults and isolate them. To confirm the system performance, the fault modes were simulated. The result showed the reliability and safety of the pedal simulator for dealing with unexpected faults.
The Nonexistence of Three Degrees of Freedom Rotational Fully Decoupled Parallel Mechanism
Authors: Hou Yu Lei , Zeng Da Xing , Duan Yan Bin , Zhao Yong Sheng
Published: March 2013

The existence of coupling makes the parallel mechanism possess some special advantages over the serial mechanism, while it is just the coupling that brings about the parallel mechanism some difficulties in kinematics and dynamic analysis, the development of control system, and the trajectory planning. Therefore the research on the decoupled parallel mechanism becomes one of the hot of the mechanism fields. While whether the parallel mechanism can realize decouple is the premise for synthesis and analysis of the parallel mechanism. Based on screw theory, the existence of the three degrees of freedom (3-DoF) rotational fully-decoupled parallel mechanism is distinguished. Then taking the 6-PUS/UPU parallel mechanism as example, the rotation angles of the moving platform are measured, which is verified the impossibility of the 3-DoF rotation decoupling. The contents of this paper should possess theoretical significance for the innovative configuration synthesis and structure design of rotational decoupled parallel mechanism.
The Squeeze Film Damping Effect on Dynamic Responses of Micro-Electromechanical Resonators
Authors: Sun Shih Chieh , Chung Chi Wei , Hsu Chao Ming , Kuang Jao Hwa
Published: March 2013

The air squeeze film damping effect on the dynamic responses of clamped micro- electromechanical resonators is investigated in this study. A dynamic model for a clamped micro- electromechanical resonator with the damping consideration is derived using Lagrange’s equation. The corresponding resonator eigen solutions are formulated and solved by employing the assumed-mode method. The effect of different parameters; i.e. the resonator size, ambient temperature and pressure on the squeeze film damping characteristics were simulated and investigated. The results indicate that the squeeze film damping effect may significantly affect the dynamic responses of micro-scale electromechanical resonator.
The Vibration Problem Studying in Micro Actuator System Using the Differential Transformation Method
Authors: Liu Chin Chia , Chen Ming Fei
Published: March 2013

The aim of this study is to derive the governing equation of an electrostatically actuated micro system by use of the Hamilton principle, and then the natural frequencies of a micro fixed-fixed beam are derived as the solutions to a boundary value problem with prescribed boundary conditions through the differential transformation method (D.T.M.). The differential transformation employed is a transformed function based on the Taylor series that is effective in solving nonlinear problems with fast convergence. The numerical results of the calculated natural frequencies are compared with the analytical data and were found to be in good agreement. Hence, the differential transformation method is one of the most efficient methods of simulating the electrostatic behavior of a micro-structure system, and it has a great potential for use in the analysis of the micro fixed-fixed beam.
Unmanned Vehicle Obstacle Avoidance Using Single Sensor Scan Method and Danger Zone Estimation
Authors: Lin Tz Jian , Wang Ta Chung
Published: March 2013

This paper proposes an obstacle avoidance algorithm for unmanned vehicles in unknown environment by a single sensor. The scan system is composed of an ultrasonic sensor and a servo motor which rotates from 0 to 180 degrees to obtain the distance data, and the profile of the obstacle can be depicted by a histogram which we use to find out the boundary of the obstacle. In this avoidance algorithm we will use the danger zone concept to judge whether the obstacle will cause a possible collision. The danger zone concept surrounds the vehicle by a sphere and uses the relative velocity to calculate the area in which obstacles will collide with the vehicle within a pre-specified time period. Combining the profile of the boundary of the obstacle with the danger zone concept, we can determine the maneuvers to avoid collisions.
Spot Weld Property Testing and Simulation Modeling with Failure Criteria
Authors: Hwang Hsiu Ying , Quoc Nghiem Nguyen
Published: March 2013

Spot welds have been widely used in vehicle body assembly, and can affect the performance of a vehicle. This paper studies the mechanical properties of spot weld and utilizes those properties in the numerical simulation to predict the failure behavior of a spot-welded component. The mechanical properties of a spot weld are not easy to obtain due to the size of spot weld, and the non-uniformity around the weld zone. The study utilized the hardness measured on and around the spot weld, heat treated samples with the same hardness, and then performed the tensile tests on those heat treated specimens to obtain the corresponding mechanical properties. With those testing data, the numerical simulation model was then created based on the properties obtained. A single-spot-welded part was used to correlate the results of hardware tests and numerical simulation. The study compared the results of three different modeling schemes with those of the hardware test. The results showed that the simulation model with material properties assigned to their corresponding region provided better correlation with the hardware testing results.
A High Sensitivity Index Sensor Based on No-Core Fibers
Authors: Lin Guei Ru , Fu Ming Yue , Sheng Hao Jan , Sun Hai Tao , Liu Wen Fung
Published: March 2013

A simple, small-size, compact and high-sensitivity refractive-index sensor composed of a short no-core fiber (NCF) about 20 mm in length sandwiched between two pieces of single-mode fibers is proposed in this paper. The index measurement is experimentally demonstrated with the sensitivity of 7792.85 nm/ RIU in the range from 1.440 to 1.454 and 227.14 nm/ RIU in the range from 1.300 to 1.430. This sensing mechanism is based on the induced multi-mode interfering wavelength shift in the no-core fiber when the reflective index of the fiber outside is changed.
A Novel Energy Efficient Joint Dynamic Emissive Location-Based Routing Scheme for SOFAR Channel Underwater Sensor Networks
Authors: Tsai Chia Sheng , Yang Chich Fu
Published: March 2013

The Underwater Sensor Network (UWSN) could be recorded by hydrophones suspended in the channel as earthquake monitors by seismic events on or below the seafloor generated energy. In this paper, we present a novel position of sensor devices and routing protocol towards short for Sound Fixing and Ranging channel (SOFAR) for Sound Fixing and Ranging channel technologies, which could save transmission power. The sound speed also increases towards the warmer sea surface with temperature. Thus we use the oceanography to find more efficient ways of utilizing routing protocol and in to obtain more effective detection and identification capabilities for underwater sources. We present an adaptive location-based routing protocol which can overcome the location based UWSN without Global Positioning System (GPS) position. It reduced costs of deployment in long range propagation. The performances are measured according to the energy consumption per bit in which the result of simulator is better than other routing protocols such as FBR.
A Positioning Scheme Combining Kalman Filtering with Vision Assisting for Wireless Sensor Networks
Authors: Tsai Fuan , Chiou Yih Shyh , Chang Huan
Published: March 2013

This paper presents the performance of an adaptive location estimator combining Kalman filtering (KF) scheme with vision-assisted scheme for wireless sensor networks. To improve the location accuracy, a KF tracking scheme is employed at a mobile terminal to track variations of the location estimate. In addition, with a vision-assisted calibration technique based on the normalized cross-correlation scheme, the proposed approach is an accuracy enhancement procedure that effectively removes system errors causing uncertainty in measuring a dynamic environment. Therefore, using the vision-assisted approach to estimate the locations of the reference nodes as landmarks, a KF-based scheme with the landmark information can calibrate the location estimation and improve the corner effect. The experimental results demonstrate that more than 60 percent of the location estimates computed from the proposed approach have error distances less than 1.4 meters in a ZigBee positioning platform. As compared with the non-tracking algorithm and non-vision-assisted approach, the proposed algorithm can achieve reasonably good performance.
A Robust Occupancy-Based Building Lighting Framework Using Wireless Sensor Networks
Authors: Hsiao Rong Shue , Lin Ding Bing , Lin Hsin Piao , Cheng Shu Chun , Chung Chen Hua
Published: March 2013

Wireless Sensor Networks are based on the ZigBee standard. ZigBee uses the IEEE 802.15.4 physical and MAC (medium access control) layers to provide standards-based reliable wireless data transfer. Also, ZigBee provides low-power wireless connectivity features. The features allow ZigBee-based products to be installed easily and cost-effectively. Thus, this technology has been attracting extensive research and development efforts to replace the traditional wired solutions for Building Automation Systems. However, wireless communications in indoor building environments are prone to be influenced by multiple concurrent factors, such as multi-path fading, channel contention, other radio interference, human activity and limited battery energy. Also, sensor detection is not fully reliable. Thus, system robustness is very concerning in these applications. In this paper, we propose a reliable wireless sensor network and an accurate occupancy detection mechanism. We implemented this system in an indoor building for the lighting control of public areas, including corridors, a coffee room and a washroom. The system framework was shown to be effective in terms of network communication reliability and sensor detection accuracy.