• The Journal of Korea Robotics Society
• /
• v.5 no.3
• /
• pp.270-277
• /
• 2010

Various robot platforms have been designed and developed to perform given tasks in a hazardous environment for the purpose of surveillance, reconnaissance, search and rescue, and etc. We have considered a terrain adaptive hybrid robot platform which is equipped with rapid navigation on flat floors and good performance on overcoming stairs or obstacles. Since our special consideration is posed to its flexibility for real application, we devised a design of a transformable robot structure which consists of an ordinary wheeled structure to navigate fast on flat floor and a variable tracked structure to climb stairs effectively. Especially, track arms installed in front side, rear side, and mid side are used for navigation mode transition between flatland navigation and stairs climbing. The mode transition is determined and implemented by adaptive driving mode control of mobile robot. The wheel and track hybrid mobile platform apparatus applied off-road driving mechanism for various professional service robots is verified through experiments for navigation performance in real and test-bed environment.

• Journal of Auto-vehicle Safety Association
• /
• v.13 no.1
• /
• pp.14-25
• /
• 2021

This paper presents a RLS based adaptive sliding mode observer (A-SMO) for unknown fault reconstruction in longitudinal autonomous driving. Securing the functional safety of autonomous vehicles from unexpected faults of sensors is essential for avoidance of fatal accidents. Because the magnitude and type of the faults cannot be known exactly, the RLS based A-SMO for unknown acceleration fault reconstruction has been designed with relationship function in this study. It is assumed that longitudinal acceleration of preceding vehicle can be obtained by using the V2V (Vehicle to Vehicle) communication. The kinematic model that represents relative relation between subject and preceding vehicles has been used for fault reconstruction. In order to reconstruct fault signal in acceleration, the magnitude of the injection term has been adjusted by adaptation rule designed based on MIT rule. The proposed A-SMO in this study was developed in Matlab/Simulink environment. Performance evaluation has been conducted using the commercial software (CarMaker) with car-following scenario and evaluation results show that maximum reconstruction error ratios exist within range of ±10%.

• Journal of Digital Convergence
• /
• v.17 no.11
• /
• pp.207-213
• /
• 2019

The fuel-cut coast-down driving mode is activated when the acceleration pedal is released with transmission gear engaged, and it's a default function for electronic-controlled engine of vehicles. The fuel economy becomes better because fuel injection stops during fuel-cut driving mode. A fuel-cut detection method is suggested in the study and it's based on the speed, acceleration and road gradient data from GPS sensor. It detects fuel-cut driving mode by comparing calculated acceleration and realtime acceleration value. The one is estimated with driving resistance in the condition of fuel-cut driving and the other is from GPS sensor. The detection accuracy is about 80% when the method is verified with road driving data. The result is estimated with 9,600 data set of vehicle speed, acceleration, fuel consumption and road gradient from test driving on the road of 12km during 16 minutes, and the road slope is rather high. It's easy to detect fuel-cut without injector signal obtained by connecting wire. The detection error is from the fact that the variation range of speed, acceleration and road gradient data, used for road resistance force, is larger than the value of fuel consumption data.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.20 no.9
• /
• pp.11-17
• /
• 2006

We have theoretically investigated the effects of the interplay between the driving voltage of Mach-Zehnder(MZ) modulators and the bandwidth of low-pass filters(LPF) in 10[Gb/s] duobinary modulation systems. For the change of driving voltage ratios(driving voltage/switching voltage), the transmission performance has been evaluated over 200[km] of single-mode fiber(SMF) systems. For driving voltage ratios with smaller than 100[%], the transmission performance has been maintained and greatly affected by the bandwidth of LPFs than the driving voltage. For driving voltage ratios with larger than 100[%], the transmission performance has been degraded and is not sensitive to the bandwidth of LPFs. To see the limitation of driving voltage, we have reduced the driving voltage ratio to 50[%]. Our results suggest that 10[Gb/s] duobinary signals with driving voltage ratio with smaller than 100[%] have been transmitted over 200[km] SMF within 2[dB] power penalty without dispersion compensation. For the driving voltage ratio with 50[%], we have verified that the transmission performance was maintained.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.1
• /
• pp.159-165
• /
• 2010

The moving object monitoring and transforming personal robot system based on remote controls is designed and implemented, and the performance of the system is analyzed in this paper. The major considering factors in the system design are such as 1) the control scheme design (button based and the remote control schemes); 2) the operation modes design (wheel driving mode/pedestrian mode/auto driving mode/observation mode); 3) the remote control function design; 4) the design of the monitoring function of the changes in neighbor environments; 5) the design of the detection of obstruction. From the experiments, it is assured that the developed personal robot can walk to the grounds that covered with doorsill or electric wires in indoors by control the leg articulations, and can escape from the obstruction using three infrared sensors in the 30cm*30cm obstruction styled space under the auto driving mode.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.57-61
• /
• 2011

The bimodal tram was designed to drive on the dedicated track as well as on the public road. The position and speed are automatically controlled on the dedicated track by the onboard computer, whereas they are manually controlled by driver like motor vehicles on the public road. The ride comfort the passengers feel and the effect of the vibration generated during driving on the passenger's health, comfortableness and motion sickness were evaluated with driving the bimodal tram prototype in automatic and manual mode, respectively. The test was done in automatic mode on the test track with various load conditions while it was done in manual mode on the public road with empty load.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.911-914
• /
• 2004

This paper discusses on new two LCD technologies featured by the fast electro-optic response:one is polymer-stabilized FLCDs that exhibit V-shaped electro-optic (EO) switching called PSV-mode FLCDs with response time of 400 ${\mu}$ s; and the other is TN-mode LCDs that exhibit a frequency modulation response (called PM-TN LCDs)and a peculiar sensitivity to the high frequency component of driving voltage waveforms resulting in a short decay time constant of 5ms and an enhancement in the over-driving that yields short response time of 1ms between two gray levels.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.22 no.2
• /
• pp.437-443
• /
• 1998

Automobile company tries to reduce the inertia of powertrain to increase the fuel efficiency and increase the engine power every year to make the high speed driving possible at full load condition. These cause the torsional vibration of powertrain. But the demand about ride comfort improvement is increased constantly, so torsional vibration of powertrain become an emergency problem to be cured. This study is a basic research to reduce the torsional vibration of powertrain at driving condition. First, the heavy duty powertrain is characterized as a vibrating system. Its natural frequencies and mode shapes are reviewed. Second, by comparison of simulation results and experiment results, validity of developed model is verified. Finally, the couterplan which can reduce the torsional vibration by mode analysis and parameter modification is suggested.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.53 no.3
• /
• pp.123-127
• /
• 2004

Mode conversion type ultrasonic rotary motor using bolt tightened Langevin type vibrator was studied. Driving frequency of the motor, displacements and elliptical trajectories at tip of the coupler were simulated by finite element analysis program (ANSYS). Speed and torque of the fabricated motor were measured as functions of input voltage and load. As results, from FEA the driving frequency of 40.8[kHz] and useful elliptical trajectories were found. Fabricated motor rotated clockwise at frequency of 38.2[kHz]. Speed and torque of the motor were increased when the input voltage was increased. Maximum speed, torque and efficiency were 75[rpm], 0.14[Nm] and 6.28[％], respectively.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.562-566
• /
• 2005

Toshiba Matsushita Display Technology (TMD) has firstly succeeded in mass production of OCB (Optically Compensated Bend) mode liquid crystal display panels which have excellent moving picture quality almost the same as CRT. We have newly developed 32 -inch diagonal HD ($1366{\times}768\;pixels$) panels using OCB mode and low temperature p-Si TFT (LTPS) array substrates. High performance of brightness of $600cd/m^2$ and contrast ratio of 600 : 1 was obtained by using pseudo-impulse driving method to insert a black period between continuous two frames, and also by using blinking backlight method. Furthermore, moving picture response time (MPRT) 6.5ms has been obtained by optimization of black insert driving and backlight blinking, without the great sacrifices of contrast ratio and luminance.