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Full-Text Articles in Computer Engineering

Mouse Type Ballbot Identification And Control Using A Convex-Concave Optimization, Sudchai Boonto, Surapong Puychaisong Oct 2020

Mouse Type Ballbot Identification And Control Using A Convex-Concave Optimization, Sudchai Boonto, Surapong Puychaisong

Journal of Marine Science and Technology

This paper shows how to identify and control a mouse type Ballbot. The Ballbot is an unstable complex system. Using the first principle law to model the robot is not accurate enough. An identification method is proposed. The model is transformed to be MIMO state space model and using a convexconcave optimization to design a robust PI+phase-lead controller. Experiments on a design Ballbot are presented. It turns out that an identification model of Bollbot and a PI+phase-lead controller design framework is suitable for using to control a Ballbot


A Survey Of Advanced Control Methods For Permanent Magnet Stepper Motors, Yong Woo Jeong, Youngwoo Lee, Chung Choo Chung Oct 2020

A Survey Of Advanced Control Methods For Permanent Magnet Stepper Motors, Yong Woo Jeong, Youngwoo Lee, Chung Choo Chung

Journal of Marine Science and Technology

Permanent Magnet (PM) stepper motors have been widely used in industry due to their low material costs and robustness against the environment. Furthermore, it is relatively easy to implement a control system compared to other type motors. It has been recently reported that advanced control methods show improved tracking performance over the conventional microstepping control. In this paper, we make a survey of advanced control methods for PM stepper motors. First, we introduce basic principles of open-loop control of PM stepper motors, including microstepping. Then we explain various advanced feedback control techniques based on Lyapunov stability. Second, we briefly summarize …


Adaptive Pid-Like Control Using Broad Learning System For Nonlinear Dynamic Systems, Ching-Chih Tsai, Chun-Chieh Chan, Chien-Cheng Yu, Hung-Sheng Chen, Guo-Shun Hung Oct 2020

Adaptive Pid-Like Control Using Broad Learning System For Nonlinear Dynamic Systems, Ching-Chih Tsai, Chun-Chieh Chan, Chien-Cheng Yu, Hung-Sheng Chen, Guo-Shun Hung

Journal of Marine Science and Technology

This paper presents a new learning control structure using broad learning system (BLS) for adaptive PID-like control of unknown digital nonlinear dynamic systems with time delays. The proposed control method, abbreviated as BLS-APIDLC, is novel in combining BLS and model predictive control to develop a new PID-like control law for high-performance setpoint tracking control and disturbance rejection. Comparative simulations on two renowned nonlinear digital time-delay systems are well used to show the effectiveness and superiority of the proposed method by comparing to four existing methods. I


Control Barrier Function Design Using Revived Transformation, Maki Takai, Motoi Igarashi, Hisakazu Nakamura Oct 2020

Control Barrier Function Design Using Revived Transformation, Maki Takai, Motoi Igarashi, Hisakazu Nakamura

Journal of Marine Science and Technology

The state constraint problem is an essential topic in control theory, wherein control methods using a control barrier function (CBF) and a revived transformation have been recently proposed. However, a way of designing the CBF is yet to be developed in a constrained space. In this study, we propose a CBF design method by using a revived transformation. Our method can design a CBF in a constrained space by utilizing a diffeomorphism from an unconstrained space. We demonstrate the effectiveness of the proposed method by human assist control design and computer simulation.


The Research Of The Rfid Anchor Assisted Slam On An Autonomous Patrolling System, Chien-Wu Lan, Che-Hung Liu Oct 2020

The Research Of The Rfid Anchor Assisted Slam On An Autonomous Patrolling System, Chien-Wu Lan, Che-Hung Liu

Journal of Marine Science and Technology

To allow service robots to patrol indoors is a difficult challenge of the robot control technology. As long as this purpose can be achieved, it can increase the value of service robots in the commercial applications. In this research, an anchor deployment strategy combined with a stereo vision system for the robot synchronization positioning and mapping is proposed, which is based on an open source Gmapping Simultaneous Localization and Mapping (SLAM) algorithm of Robot Operating System (ROS), and enables a robot to simultaneously positioning and build environment maps autonomously. The anchors are developed based on the radio frequency identification (RFID), …


Robotic Suturing In Minimally Invasive Surgery, Jia-Yush Yen, Hao-Xiang Kang, Kuan Shen, Yung-Yaw Chen, Ming-Chih Ho Oct 2020

Robotic Suturing In Minimally Invasive Surgery, Jia-Yush Yen, Hao-Xiang Kang, Kuan Shen, Yung-Yaw Chen, Ming-Chih Ho

Journal of Marine Science and Technology

Minimally invasive surgery (MIS) has the advantages of minimal bleeding and rapid postoperative recovery, which can alleviate patient suffering. Therefore, MIS is widely used in clinical applications. However, MIS is more difficult than traditional surgery; surgeons must be more meticulous when performing MIS than when performing ordinary surgery. Using a robotic arm in an auxiliary role in MIS can reduce the workload of surgeons and increase the precision and efficiency of the surgical procedure. The aim of this article is to design an MIS robot system that can perform automatic surgical suturing. First, we designed the basic control architecture for …


Motion And Control Simulation For Underwater Robots, Shyh-Kuang Ueng, Chieh-Shih Chou Oct 2020

Motion And Control Simulation For Underwater Robots, Shyh-Kuang Ueng, Chieh-Shih Chou

Journal of Marine Science and Technology

Remotely Operated Vehicles (ROVs) are widely used in underwater explorations and constructions. When navigating under the sea, the motions and stabilities of ROVs are influenced by various forces. Operating ROVs to capture images, grasp samples, avoid obstacles, and examine man-made facilities is challenging. This paper proposes an innovative simulator to train users to handle ROVs. Conventional simulators only can mimic undeformable ROVs. Their educational capabilities are limited. The proposed simulator is developed based on advance mathematics models and is able to emulate a ROV equipped with movable robot arms. Therefore, it can perform more realistic and meaningful simulations to enhance …


Agile Rov For Underwater Surveillance, Ikuo Yamamoto, Akihiro Morinaga, Murray Lawn Oct 2020

Agile Rov For Underwater Surveillance, Ikuo Yamamoto, Akihiro Morinaga, Murray Lawn

Journal of Marine Science and Technology

Surveillance of submerged plant is becoming increasingly critical as ocean based resources become more and more important. A wide varieties of new roles have recently emerged ranging from aquaculture to offshore power generation systems, in addition to the monitoring of the aging submerged sections of bridges, piers and dams etc. Consecutive generations of ROVs have been developed at Nagasaki University to meet the changing needs for surveillance of submerged plant. This paper outlines briefly the ROVs developed to date and the move to increase ROV autonomy using AI (artificial intelligence).


Gain-Scheduled Control Of Discretized Ship Autopilot System Subject To Poleassignment And Passivity Constraints, Wen-Jer Chang, Cheung-Chieh Ku, Chih-Yu Yen, Guan-Wei Chen Oct 2020

Gain-Scheduled Control Of Discretized Ship Autopilot System Subject To Poleassignment And Passivity Constraints, Wen-Jer Chang, Cheung-Chieh Ku, Chih-Yu Yen, Guan-Wei Chen

Journal of Marine Science and Technology

This paper addresses a control performance problem for discretized ship autopilot system with uncertainty. To completely express the uncertainty, Linear Parameter Varying (LPV) modelling technology is employed such that the ship autopilot system is described via several linear systems and weighting function. Furthermore, gain-scheduled scheme is applied to design a controller to achieve the passivity and pole-assignment constraints. Moreover, a Parameter-Dependent Lyapunov Function (PDLF) is used to derive some sufficient conditions. Through the proposed design method, the attenuation performance and stability of the system can be guaranteed. Besides, the transient responses are furtherly improved such that the ship autopilot system …


Path Planning And Obstacle Avoidance Of Uav For Cage Culture Inspection, Yi-En Cai, Jih-Gau Juang Oct 2020

Path Planning And Obstacle Avoidance Of Uav For Cage Culture Inspection, Yi-En Cai, Jih-Gau Juang

Journal of Marine Science and Technology

This paper presents path planning and obstacle avoidance of an unmanned aerial vehicle (UAV) for cage culture inspection. The proposed system can automatically inspect cage farming environment that can cut manpower and reduce cost. The problem is similar to travelling salesman problem (TSP). Genetic algorithms are useful techniques for TSP and can also be used for cage culture inspection. In addition to path planning, an improved particle swarm optimization (IPSO) is applied to avoid obstacle between different cages. The IPSO is applicable to both stationary and dynamic environments with one or more obstacles. Simulation results show the effectiveness of the …


Container Throughput Forecasting For International Ports In Taiwan, Juan Huang, Ching-Wu Chu, Yi-Chen Tsai Oct 2020

Container Throughput Forecasting For International Ports In Taiwan, Juan Huang, Ching-Wu Chu, Yi-Chen Tsai

Journal of Marine Science and Technology

This paper compares different univariate forecasting methods and provides a more accurate short-term forecasting model for container throughput to create a reference for relevant authorities. Six different univariate methods, including the classical decomposition model, the trigonometric regression model, the regression model with seasonal dummy variables, the grey forecasting model, the hybrid grey forecasting model, and the seasonal autoregressive integrated moving average (SARIMA) model, were used. We found that the SARIMA model is a reliable forecasting method for forecasting container throughput with seasonal variations. This study’s findings can help to predict the near-future demand for container throughput at international ports.


Constraints To Guarantee Gain And Phase Margins For Data-Driven Controller Tuning Methods, Taiga Sakatoku, Kazuhiro Yubai, Daisuke Yashiro, Satoshi Komada Oct 2020

Constraints To Guarantee Gain And Phase Margins For Data-Driven Controller Tuning Methods, Taiga Sakatoku, Kazuhiro Yubai, Daisuke Yashiro, Satoshi Komada

Journal of Marine Science and Technology

The Noniterative Correlation-based Tuning (NCbT) is one of the data-driven controller tuning methods which directly tune controller parameters from input/output data set of a plant . The NCbT is based on the correlation approach to robustly tune controller parameters using a noisy input/output data set. Since the NCbT guarantees closed-loop stability only for the situation where the data is acquired, a plant fluctuation is not taken into consideration, which may lead to degradation of control performance and/or destabilization of the closed-loop system . In this paper, we virtually produce input/output data sets of the plant with various gain and/or phase …


Reinforcement Learning Based Maximum Power Point Tracking Control Of Partially Shaded Photovoltaic System, Kuan-Yu Chou, Chia-Shiou Yang, Yon-Ping Chen Oct 2020

Reinforcement Learning Based Maximum Power Point Tracking Control Of Partially Shaded Photovoltaic System, Kuan-Yu Chou, Chia-Shiou Yang, Yon-Ping Chen

Journal of Marine Science and Technology

Under the sun insolation in the daytime, the Maximum Power Point Tracking (MPPT) technique is usually used to achieve the maximum power in the photovoltaic (PV) system and often implemented by the Perturbation and Observation (P&O) method. However, due to the use of fixed step size, the P&O method will generate undesired oscillation around the maximum power point (MPP) and thus reduce the tracking efficiency. Besides, the output power of PV modules highly depends on the environment factors such as irradiance and temperature, especially for a PV array, which is formed by PV modules connected in series and parallel. The …


Performance Comparison Of The Stbc-Ofdm Decoders In A Fast Fading Channel, Chi-Min Li, Guo-Wei Li, Han-Yi Liu Oct 2012

Performance Comparison Of The Stbc-Ofdm Decoders In A Fast Fading Channel, Chi-Min Li, Guo-Wei Li, Han-Yi Liu

Journal of Marine Science and Technology

In a fast fading channel, the orthogonality of the two consecutive STBC-OFDM symbols will be destroyed and the received signals can not be perfectly separated. As a result, the bit error rate (BER) performance will be degraded seriously. In this paper, we analyze several co-channel interference (CCI) cancellation decoders for the STBC-OFDM in a fast fading channel including the Alamouti method, SIC method, ML method, DMLD method, and a proposed DZFD method. The proposed DZFD method has the advantage of reducing the computational complexity for the DMLD method. We also conduct the outdoor channel measurements to verify the CCI cancellation …


A Partition Dummy Sequence Insertion Papr Reduction Method Of The Ofdm System, Chi-Min Li, Jia-Chyi Wu, Chao-Chin Tseng Oct 2012

A Partition Dummy Sequence Insertion Papr Reduction Method Of The Ofdm System, Chi-Min Li, Jia-Chyi Wu, Chao-Chin Tseng

Journal of Marine Science and Technology

OFDM (Orthogonal Frequency Division Multiplexing) technique has been widely adopted in many wireless communication systems due to its high data-rate transmission ability and robustness to the multipath fading channel. One major drawback of the OFDM signal is the high peak-toaverage power ratio (PAPR) problem. The high PAPR results in the in-band distortion and out-of-band radiation when the OFDM signal is fed into a nonlinear power amplifier (PA). In this paper, we propose a partition dummy sequence insertion (PDSI) method to reduce the PAPR problem. Simulation results of the PAPR reduction and bit error rate (BER) performance for the proposed method …


A Color Image Authentication And Recovery Method Using Block Truncation Code Embedding, Shu-Chien Huang, Ching-Fen Jiang Feb 2012

A Color Image Authentication And Recovery Method Using Block Truncation Code Embedding, Shu-Chien Huang, Ching-Fen Jiang

Journal of Marine Science and Technology

A new method for color image authentication and recovery is proposed in this paper. To achieve this goal, the least significant bit (LSB) and the second LSB of the spatial domain were selected to embed the watermark. The watermark consists of two parts: authentication data and recovery data made by block truncation code and bitmap. According to the experimental results, the image embedded within the authentication data and recovery data can still preserve high image quality. The results also reveal that the tampered images can be successfully recovered with acceptable visual quality.


Particle Swarm Optimization For Global Optimization Problems, Hsin-Chuan Kuo, Jiang-Ren Chang, Ching-Hsiang Liu Dec 2006

Particle Swarm Optimization For Global Optimization Problems, Hsin-Chuan Kuo, Jiang-Ren Chang, Ching-Hsiang Liu

Journal of Marine Science and Technology

In this paper, the particle swarm optimization (PSO), originated as a simulation of a simplified social system with swarm intelligence and having exploring and exploiting characteristics of the particle swarm, is adopted to deal with the global optimization problems. To begin with, four non-linear two-dimensional functions are adopted as benchmark examples for determining the suitable ranges of parameters in the PSO. It is found that uses of the PSO can make the search quickly converge to the global optimum. Then, several benchmark functions below ten-dimensions are adopted especially for comparisons of search efficiency on the PSO and other algorithms. Results …


Web Services Of Mms Applications On Mobile Devices, Cheng-Chih Yang, Cheng-Min Lin Dec 2006

Web Services Of Mms Applications On Mobile Devices, Cheng-Chih Yang, Cheng-Min Lin

Journal of Marine Science and Technology

This study develops the Web services that are applied in Multimedia Message Service (MMS) applications via the Internet and operated by mobile portable devices, such as Personal Digital Assistant (PDA) and cellular phone. First, a MMS system environment and architecture is modeled. Next, the operations and interface of the MMS system is defined by the Web Services Description Language (WSDL) to represent the web services on MMS application system. Finally, two system prototypes are described in this study that includes distance video cam monitor system and GPRS cellular phone MMS sender.


Performance Analysis Of Mc-Cdma Communication Systems Over Nakagami-M Environments, Joy Iong-Zong Chen Mar 2006

Performance Analysis Of Mc-Cdma Communication Systems Over Nakagami-M Environments, Joy Iong-Zong Chen

Journal of Marine Science and Technology

The performance for a MC-CDMA (multi-carrier coded-division multiple-access) system working in uncorrelated and correlated fading channels with Nakagami distribution is investigated in this paper. We adopt the BPSK modulation scheme with an alternative expression for Q-function to evaluate the BER (bit error rate) performance of the MC-CDMA system. The sum of Gamma variates is adopted for deriving a closed-form solution for arbitrarily correlated channel in order to avoid the difficulty of explicitly obtaining the pdf (probability density function) for the SNR (signal-to-noise ratio) at the MRC (maximum ratio combining) output. The results with simple expression obviously show that the BER …