• Journal of the Korean Society for Precision Engineering
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• v.30 no.11
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• pp.1161-1169
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• 2013

In this paper an omni-directional mobile robot is suggested for educational robot platform. Comparing to other robots, a mobile robot can be easily designed and manufactured due to its simple geometric structure. Moreover, since it is required to have low DOF motion on planar space, fabrication of control system is also simple. In this research, omni-directional wheels were adopted to remove the non-holonomic characteristic of conventional wheels and facilitate control system design. Firstly, geometric structure of a Mecanum wheel which is a most frequently used omni-directional wheel was demonstrated. Then, the organization of the mobile platform was suggested in aspects of mechanism manufacturing and electronic hardware design. Finally, a methodology of control system development was introduced for educational purpose. Due to an intuitive motion generating ability, simple hardware composition, and convenient control algorithm applicability, the omni-directional mobile robot suggested in this research is expected to be a promising educational platform.

• Journal of Power Electronics
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• v.16 no.5
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• pp.1698-1705
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• 2016

In this paper, a hardware-in-the-loop simulation platform for MMCs is established, which connects a real time digital simulator (RTDS) and a designed MMC controller with optical fiber. In this platform, the converter valves are simulated with a small time step of 2.5 microsecond in the RTDS, and multicore technology is implemented for the controller so that the parallel valve control is distributed between different cores. Therefore, the designed controller can satisfy the requirements of real-time control. The functions of the designed platform and the rationality for the designed controller are verified through experimental tests. The results show that different modulation modes and various control strategies can be implemented in the simulation platform and that each control objective can been tracked accurately and with a fast dynamic response.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.7
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• pp.1074-1080
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• 2015

In the last decades, the increasing interest in unmanned aerial vehicle(UAV) for military, surveillance, and rescue applications made necessary the development of flight control theory and body structure more and more efficient and fast. In this paper, we describe the design and performance of a prototype hexarotor UAV platform featuring an inertial measurement unit(IMU) based autonomous-flying for use in bluetooth communication environments. The proposed system comprises the construction of the test hexarotor platform, the implementation of an IMU, dynamic modeling and simulation in the hexarotor helicopter. Furthermore, the hexarotor helicopter with implemented IMU is connected with a micro controller unit(ARM-cortex) board. The P-PD control algorithm was used to control the hexarotor. We used the Matlab software to help us to tune the P-PD control parameters for quick response and minimizing the fluctuation. The control simulation and experiment on the real system are implemented in the test platform, evaluated and compared against each other.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.12
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• pp.993-1000
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• 2001

Configuration-dependent nonlinear coefficient matrices in the dynamic equation of robot manipulator impose computa- tional burden in real-time implementation of tracking control based on the inverse dynamics controller. However, parallel manipulators such as Stewart platform have relatively small workspace compared to serial manipulators. Based on the characteristics of small motion range. nonlinear coefficient matrices can be approxiamted to constant ones. The modeling errors caused by such approximation are compensated for by H-infinity controller that treats the modeling errors disturbance. The proposed inverse dynamics controller with approximate dynamics combined with H-infinity control shows good tracking performance even for fast tracking control in which computation of full inverse dynamics is not easy to implement.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.804-807
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• 1996

In this paper, a new model of TDF(two degree of freedom) spin-stabilized platform has been suggested. The platform driving signal modulated in the spinning frequency is described in demodulated form keeping its precession angular velocity. When a strong spinning torque exists, the cross-axis spring constant cannot be neglected in modelling of the platform precession dynamics. A linearized dynamic model of spin-stabilized platform pointing loop is derived and validated through the comparison between simulation and experimental results.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.31-39
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• 2013

A virtual chassis platform for Fuel Cell Hybrid Electric Vehicles(FCHEV) has been developed, and a virtual platform similar to the actual system has been composed. In addition, major components such as a motor, fuel cell and battery for the virtual platform have been constructed by using a mathematical formulation. The FCHEV virtual platform using a detailed model based on the mathematical formula is capable of simulating various conditions according to changes of the control logic and component modules to evaluate performance, considering the vehicle dynamic characteristics. Usability of the mathematical model has been verified by comparative simulations according to the motor current control variation. In addition, reliability of the developed virtual chassis platform has been verified by simulating its fuel consumption with the UDDS(Urban Dynamometer Driving Schedule) FTP-72 velocity profile.

• Journal of the Korea Society of Computer and Information
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• v.22 no.10
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• pp.47-54
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• 2017

In this paper, we propose a connected car platform architecture called Mobile Second for developing of verity convergence services. A Mobile Second platform architecture is designed to provide more powerful and diverse convergence services for vehicles and drivers by applying technologies of Connected Car and ICT Convergence in various ways. The Mobile Second platform is implemented by applying Tizen IVI and Android to hardware platforms for IVI, Nexcom's VTC1010 and Freescale's i.MX6q/dl respectively. The Mobile Second platform provides the driver with the vehicle's information via IVI devices, mobile devices and PCs, etc., and provides Vehicle Selective Gateway(VSG) and Vehicle Control Framework for the driver to control his/her vehicle, and also provides a web framework to enable the use of VSG's APIs for the monitoring and controlling the vehicle information in various mobile environments as well as IVI devices. Since the Mobile Second platform aims to create new variety of services for Connected Car, it includes service frameworks for Smart Care / Self diagonostics, Mood & Entertainment services, and Runtime, libraries and APIs needed for the development of related applications. The libraries given by the Mobile Second Platform provides both a native library for native application support and a Java Script-based library for web application support, minimizing the dependency on the platform and contributing the convenience of developers at the same time.

• International Journal of Safety
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• v.9 no.2
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• pp.35-40
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• 2010

Many casualties are being occurred due to many misses the railway platform, and the accident occurrence is being increased. Recently in Korea, efforts to prevent casualties fundamentally are being made by installing and operating the PSD(Passenger Screen Door) as to prevent these casualties of passengers. However, in case of the PSD system, although it can solve the problem of public casualties at platform fundamentally, it is impossible to install it at whole railway platforms. This paper proposes the safety equipment using LaserRadar sensor for the prevention against casualties of passengers at platform. The safety equipment using novel sensor is the safety equipment making an approaching train stopped if the falling object is a person by detecting the obstacle at platform, and it has the merit possible to apply it to platform since it may detect accurately under ambient environmental elements such as the snow, rain and yellow dust, etc. also. We manufactured a prototype of the safety equipment to reduce public casualties at platform by using LaserRadar sensor and carried out its performance test, and the result is presented in this paper.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.11 s.170
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• pp.1982-1992
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• 1999

This paper presents a novel concept of cargo handling system adapted for a sea port subjected to severe time-varying tide. The proposed system can perform loading or unloading by using a sort of hydraulic elevator associated with real-time position control. In order to achieve a proof-of-concept, a small-sized laboratory model of the cargo handling system is designed and built. The model consists of three principal components container palette transfer (CPT) car, platform with lifting columns, and cargo ship. The platform activated by electro-rheological (ER) valve-cylinders is actively controlled to track the position of the cargo ship subjected to be varied due to the time-varying tide and wave motion. Following the derivation of the dynamic model for the platform and cargo ship motions, an appropriate control scheme is formulated and implemented. The location of the CPT car is sensed by a set of photoelectric switches and controlled via sequence controller. On the other hand, a sliding mode controller (SMC) is adopted as the position controller for the platform. Both simulated and measured control results are presented to demonstrate the effectiveness of the proposed cargo system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.1
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• pp.96-103
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• 2009

This paper presents a L3 mobile terminal platform of the mobile terminal system which is a subsystem of HMm(Hig-speed Mobile Multimedia) system, which layer 3 control protocols such as RC(Radio Control), SC(Session Control), MC(Mobility Control) and application services such as VOD, FTP, VoIP for a multimedia mobile terminal are implemented on. The hardware platform is based on PXA255 and supports various interfaces and multimedia devices, and under the platform, an embedded Linux generated by the self-maden cross-toolchain, L3 control protocols and application programs were installed. The operation of HMm system under the HMm testbed has shown that this platform successfully supported SIP services, web browsing services, streaming services and etc as well as call processing. It could be the reference of the upcoming Fourth-Generation mobile terminal which the multimedia functionality will be enforced.