• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.2
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• pp.15-24
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• 2016

GPS(Global Positioning System) location tracking is a method for taking the precise coordinates after the coordinates are obtained by a GPS receiver, and displaying them on the map. In this paper with WAVE(Wireless Access for Vehicular Environment) simulation, we show that various services such as vehicle tracking service, real-time road conditions service and logistics can go tracking service, control and operation services according to the vehicle position and the traveling direction by using the GPS position data. A vehicle tracking system using GPS is automatically able to manage multiple RCP when exchanging data between RMA and the RCP, and it provides rapid requests and responses. To verify that multiple sessions between RMA and RM, as well as multiple sessions between RMA and RCP are able to be implemented, we take RMA as a RCP application on an OBU, until the RMA is receiving data response from corresponding RM. As a result of this experiment, we show that the response speeds of single session between RMA and RM using 1, 2, 3, and 4 kbyte unit data are similar, 62.32ms, 62.65ms, 63.02ms, and 63.48ms, respectively. Likewise, those of 128 muliple sessions using 1, 2, 3, and 4 kbyte unit data are not much more time difference, 298.08ms, 302.21ms, 322.85ms, and 329.62ms, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.12
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• pp.1675-1683
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• 2018

This paper is a study on modeling of an NFC antenna to be inserted into a steel pallet for conveying selected good products through a vision system to a threaded screw from CNC equipment. The CNC equipment used here incorporates the information communication technology (ICT) corresponding to the Internet of Things (IoT), and the smart factory system technology that produces information by exchanging information freely in two directions by connecting the POP corresponding to the service Internet is evolved Equipment. Therefore, it is possible to collect position information on the threaded workpiece by applying NFC antenna designed considering iron pallet used for material management so as to grasp estimated completion time and actual production amount according to production instruction from existing analog type equipment to POP monitoring system And investigated its characteristics.

• Journal of Mechanical Science and Technology
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• v.17 no.3
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• pp.336-342
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• 2003

Increasing demand on precision machining using computerized numerical control (CNC) machines have necessitated that the tool move not only with the smallest possible position error but also with smoothly varying feedrates in 3-dimensional (3D) space. This paper presents the simultaneous 3D machining process investigated using a retrofitted PC-NC milling machine. To achieve the simultaneous 3-axis motions, a new precision interpolation algorithm for 3D Non Uniform Rational B-Spline (NURBS) curve is proposed. With this accurate and efficient algorithm for the generation of complex 3D shapes, a real-time NURBS interpolator was developed using a PC and the simultaneous 3D machining was accomplished satisfactorily.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.7
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• pp.1156-1165
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• 1997

Complex modal testing is employed for the in-situ parameter identification of a four-axis active magnetic bearing system while the system is in operation. In the test, magnetic bearings are used as exciters as well as actuators for feedback control. The experimental results show that the directional frequency response function, which is properly defined in the complex domain, is a powerful tool for identification of bearing as well as modal parameters. It is also shown that the position and current stiffnesses can be accurately estimated using the relations between the measured forces, displacements, and currents.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.5
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• pp.418-426
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• 2016

This paper analyzes the effect of resistance error to the performance of sensorless drive system of surface-mounted permanent magnet synchronous machine (SMPMSM) based on the back-EMF observer. The analysis shows that the bandwidth of the entire sensorless drive system decreased in the low-speed region when using smaller resistance value than the actual one in the back-EMF observer. Even if the back-EMF observer invokes estimation error, the entire sensorless drive system does not make any steady-state position error. These characteristics may have positive effects such as extension of the low speed limit that goes further down in the sensorless drive. The validity of the analysis is verified by the experimental setup comprising the MG set.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.3
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• pp.85-92
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• 2002

This paper presents the effects of design and operating parameters to meet the static and dynamic performances of the electro-mechanical valve(EMV) actuator which can provide more flexible controllability of valve events compared to conventional variable valve actuation devices. The model of the EMV system was also set up and applied to identify the dynamic behavior of the system. And the effects of external disturbances were also investigated such as cylinder pressure, armature neutral position and current supplying time effects and so on. Experiments were carried out to verify the model using the prototype actuator on test bench, it was found that there is a relatively good agreement between experimental data and modeling results. Also, the actuators meet the general engine speed range (over 6000rpm) and the variable valve event control for various VVT effects.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1640_1641
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• 2009

Dynamic friction and force ripple are the most predominant factors that affect the positioning accuracy of permanent magnet synchronous motor(PMSM) servo drives system, and it is desirable to compensate them in finite time with a continuous control law. In this paper, based on LuGre dynamic friction model, a robust adaptive skidding mode controller is proposed to compensate the nonlinear effect of friction and force ripple. The controller scheme consists of a PD component and a robust adaptive sliding mode controller for estimating the unknown system parameter. Using Lyapunov stability theorem, asymptotic stability analysis and position tracking performance are guaranteed. Simulation results well verify the feasibility and the effectiveness of the proposed scheme for high0precision motion trajectory tracking.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.771-776
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• 2002

Optimal shape of the NFR suspension is studied and developed to improve the dynamic performance and reduce the vibration of the suspension system including a optical head slider. Since accurate position control and stability of the slider motion are highly required in NFR due to the narrower track width and the heavier slider than HDD slider with the low flying height, the dynamic characteristics of the suspension are very important to the mechanical performance of the system. The first natural frequencies in flexural and lateral motion of the suspension are critical factors affecting the dynamics and stability of the flying head, so that the dynamic parameters should be designed properly to avoid an excessive vibration or a crash of the slider on the disk. This paper optimizes the shape of the suspension based on homogenization method in NASTRAN and develops a new suspension shape for NFR system. The suspension is tested on experiment to verify the improvement of the dynamic characteristics.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.71-71
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• 2012

To control luminescence emission property, a novel series of strong fluorescent fluorin-boron complexes were synthesized in higher yield. The resulting structural analysis was completed. Small molecules with a built-in fluorine-boron core structural architecture has been attracted considered attention as the key emissive elements due to the their good properties such as bipolar charge transport and high photo efficiency. Thus, new type of fluorine-boron(F-B) complexes are designed and prepared. Changing the substituent position on fluorophore ring provided a deep understanding on the relationship between structure and optical properties.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.71-75
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• 1999

In this paper, we present the 3DOF force-reflecting interface which allows to acquire force of object within a virtual environment. This system is composed of device, virtual environment model, and force-reflecting rendering algorithm. We design a 3 DOF force-reflecting device using the parallel linkage, torque shared by wire, and the controller of system applied by impedance control algorithm. The force-reflecting behaviour implemented as a function position is equivalent to controlling the mechanical impedance felt by the user. Especially how force should be supplied to user, we know using a God-Object algorithm. As we experiment a system implemented by the interface of 3D virtual object and 3DOF force-reflecting interface, we can feel a contact, non-contact of 3D virtual object surface and sensing of push button model.