• Journal of the Korean Society for Precision Engineering
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• v.25 no.7
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• pp.95-102
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• 2008

Since the processes of dismantling are very dangerous, there have been many studies to develop remote operating devices using joystick. In this paper, in order to improve the operability of the dismantling equipment that is usually an excavator, a novel concept of tole-operated device is proposed. Operators who use this device with additional environmental sensing devices can work safely away from the dangerous sites. First, based on the concept design of the remote controller, its workspace is analyzed and the workspace mapping from the device to the excavator is explored. Second, after 7 steps of the excavating processes are defined, the kinematics which deals with the conversion from the 3 dimensional position information of the device to the joint variable information of the backhoe is included in this paper. Lastly, 3D graphical simulation of both remote controller and the backhoe will be shown. This new design of the remote control device tan be easily manufactured and gives the workers very convenient and transparent remote control capability.

• Journal of the Korean Institute of Intelligent Systems
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• v.6 no.4
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• pp.49-60
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• 1996

The objective of this paper is to develop an adaptive learning method for fuzzy hypercubes using a neural network. An intelligent control system is proposed by exploiting only the merits of a fuzzy logic controller and a neural network, assuming that we can modify in real time the consequential parts of the rulebase with adaptive learning, and that initial fuzzy control rules are established in a temporarily stable region. We choose the structure of fuzzy hypercubes for the fuzzy controller, and utilize the Perceptron learning rule in order to upda1.e the fuzzy control ru1c:s on-line with the output errors. As a result, the effectiveness and the robustness of this intelligent controller are shown with application of the proposed adaptive fuzzy-neuro controller to control of the cart-pole system.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.5
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• pp.180-187
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• 2007

This paper presents a mathematical vehicle model that is designed to analyze the dynamic performance and to develop various safety control systems. Wheel slip controllers for ABS is also formulated to improve the vehicle response and to increase the safety on slippery road. Validation of the model and controller is performed by comparison with a commercial software package, CarSim. The result shows that performances of developed vehicle model are in good accordance with those of the CarSim on various driving conditions. Developed ABS controller is applied to the vehicle model and CarSim model, and it achieves good control performance. ABS controller improves lateral stability as well as longitudinal one when a vehicle is in turning maneuver on slippery road. A driver model is also designed to control steer angle of the vehicle model. It also shows good performance because the vehicle tracks the desired lane very well.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.6
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• pp.125-131
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• 2013

This study was carried out to develop a diesel engine for marine propulsion. This marine diesel engine was developed based on a 500Ps vehicle diesel engine. Many main parts, such as the intercooler, radiator, and engine controller were designed for the marine diesel engine. The intercooler was designed to be of sea water cooling type; inlet air is cooled by sea water. Engine coolant is cooled by sea water in the radiator too. The water cooling heat exchanger has high cooling performance. In the cooling system, consists of the intercooler and the radiator, the sea water passes through the intercooler and then the radiator, in sequence. This process is very effective compared to the reverse method in which sea water passes through the radiator and then the intercooler, in sequence. The control performance of the engine controller and the fuel injection rate were improved using an engine speed controller. This system was tested on an engine dynamometer and an exhaust gas analyzer using the marine diesel engine test method. Test results show that the 500Ps marine diesel engine satisfied the IMO NOx regulations; Tier II.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.4
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• pp.251-263
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• 2003

This paper presents matrix inequality conditions for Η$_2$control and Η$_2$controller design method of linear time-invariant descriptor systems with parameter uncertainties in continuous and discrete time cases, respectively. First, the necessary and sufficient condition for Η$_2$control and Η$_2$ controller design method are expressed in terms of LMI(linear matrix inequality) with no equality constraints in continuous time case. Next, the sufficient condition for Hi control and Η$_2$controller design method are proposed by matrix inequality approach in discrete time case. Based on these conditions, we develop the robust Η$_2$controller design method for parameter uncertain descriptor systems and give a numerical example in each case.

• Proceedings of the KWS Conference
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• 1994.10a
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• pp.89-92
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• 1994

According to the industrial development welding technology is necessitated to develop in the direction of full automation, high efficiency, energy saving, and full safety. In this study, thus, a simple holder ampere controller for welding systems is developed and applied to arc welders and its capability is examined and tested. The results are as follows: 1. It has a simple structure, since the primary AC power for the welder can be directly control led using a triac. 2. It can control the electric power strength in several steps as well as on and off easily, since a small-sized variable resistance is installed in the small controller on the welding holder. 3. In real field applications a welding system with this controller increases the working efficiency greatly compare to the conventional arc welders without the system, because the controller can control the ampere onsite far from the main power supply. 4. It can reduce the probability of the electrical mishap due to electrical leakage, since the electricity is disconnected as soon as the switch is off or welding person's hand is taken off from the welder after the work or for rest. 5. It can control the welding depth in the beginning and do the crater treatment well in the ending of welding, since it always supplies the relevent amount of electrical current. Therefore, it can improve the mechanical properties of the welding zone.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2252-2257
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• 2003

In this paper, we develop the so-called functional test model for magnetic bearing reaction wheels. The functional test model has three degree of freedom, which consists of one axial suspension from gravity and the other two axes gimbaling capability to small angle, and does not include the motor. For the control of the functional test model, we derive the optimal electromagnetic forces based on the least squares method, and use the proportional-integral-derivative controller. Then, we develop a hardware setup, which mainly consists of the digital signal processor and the 12-bit analog-to-digital and digital-to-analog converters, and show the experimental results.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.854-859
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• 2008

In a railway vehicle, contact between wheel and rail is a peculiar characteristic and variations of wheel and rail profile influence on the dynamic characteristics of railway vehicle. Thus the variations of the wheel and rail profile are very important in railway dynamics. Recently a research relating to active steering to improve the curving performance of vehicle is progressing actively at home and abroad. In this field, a pre-study for the wheel/rail contact geometry is needed and especially the variation of the wheel/rail contact geometry with wheel wear is the key design parameter to develop the controller of the active steering bogie. In this paper, we have experimentally studied to analyze the variation of the wheel/rail contact geometry with wheel wear as a pre-study to develop the active steering bogie for electric multiple unit (EMU). For this, we have made an experiment with EMU operating in curving area. We have measured the wear profiles of the wheel of the test vehicle and analyzed the wheel/rail contact geometry with a mileage of the test vehicle. In experiment with test vehicle, we have got the useful data to design the steering controller of the wheelset.

• Archives of design research
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• v.18 no.2 s.60
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• pp.201-210
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• 2005

In order to develop a more useful and ergonomically attractive remote controller, I peformed experiments with various subjects to define factors that may obstruct the usability of remote controllers for multifunction A/V appliances. I also performed the experiments to evaluate other factors that were created to improve the usability of them, and showed that remote controllers with the improved factors are more efficient and more attractive to use. I analyzed about 40 types of remote controllers for various A/V appliances to understand impediment factors of usability. By this analysis I found the factors that affected the usability of them, and developed three types of improved remote controllers for the next version of $Play@TV^{TM}$ also set the subjects with the task of usability tests with an existing remote controller and the three newly chosen remote controllers, and those results were analyzed qualitatively and quantitatively. The results showed that the 'B type' remote controller took less time to perform the same tasks by 9.2% than the existing remote controller. I concluded that the usability factors of remote controllers - function receptivity, presentation of a tactile clue, reasonable size and weight, how to arrange the main buttons, grouping of related functions - will be useful and effective to improve the usability of A/V appliances.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.3
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• pp.601-606
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• 2017

SRAM-based FPGAs mainly used to develop and implement high-performance circuits have SRAM-type configuration memory. Soft errors in memory devices are the main threat from a reliability point of view. Soft errors occurring in the configuration memory of FPGAs cause FPGAs to malfunction. SEM(Soft Error Mitigation) Controllers offered by Xilinx can mitigate the influence of soft errors in configuration memory. SEM Controllers use ECC(Error Correction Code) and CRC(Cyclic Redundancy Code) which are placed around the configuration memory to detect and correct the errors. The correction is done through a partial reconfiguration process. This paper presents the availability analysis of SRAM-based FPGAs against soft errors under the protection of SEM Controllers. Availability functions were derived and compared according to the correction capability of SEM Controllers of several different families of FPGAs. The result may help select an SRAM-based FPGA part and estimate the availability of FPGAs running in an environment where soft errors occur.