• Journal of Life Science
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• v.21 no.8
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• pp.1076-1082
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• 2011

Microtubule-based kinesin motor proteins are used for long-range vesicular transport. KIF5s (KIF5A, KIF5B and KIF5C) mediate the transport of various membranous vesicles along microtubules, but the mechanism behind how they recognize and bind to a specific cargo has not yet been completely elucidated. To identify the interaction protein for KIF5B, yeast two-hybrid screening was performed and a specific interaction with the unconventional myosin Myo9b, an actin-based vesicle transport motor, was found. The GTPase-activating protein (GAP) domain of Myo9s was essential for interaction with KIF5B in the yeast two-hybrid assay. Myo9b bound to the carboxyl-terminal region of KIF5B and to other KIF5 members. In addition, glutathione S-transferase (GST) pull-downs showed that Myo9s specifically interact to the complete Kinesin-I complex. An antibody to KIF5B specifically co-immunoprecipitated KIF5B associated with Myo9s from mouse brain extracts. These results suggest that kinesin-I motor protein interacts directly with actin-based motor proteins in the cell.

• Journal of the Korean Society of Propulsion Engineers
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• v.1 no.2
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• pp.91-102
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• 1997

In order to evaluate the effects of aging on the ignition performance, pyrotechnic igniters were separated from twelve-year-old, fifteen-year-old, and sixteen-year-old live rocket motors. The characteristic values of the ignition material were measured, and the firing tests of the igniters were performed. The moisture content, the outer dimension, the crush strength, the thermal decomposition characteristics, and the heat of formation the B/$KNO_3$ ignition pellet were measured. The crush strength was increased and the heat of formation was reduced as aged, but no change was detected for other characteristic values. The burning test results of the igniter pellet in the closed bomb and the inert motor showed that the burning rate of the ignition pellet was increased by 10%, and the integration of pressure $P_t$ of the p-t curve was reduced by 15% for aged samples. It was inferred that the burning rate was increased as the crack was appeared in the pellet and $P_t$ could be proportionally decreased with the heat of explosion.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.4
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• pp.56-65
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• 2013

The word is endeavoring to reduce greenhouse gases with the sense of crisis caused by the continuous climate change. As a method to decrease greenhouse gases, motors driven by fossil fuels are being substituted by EV in the field of transportation. Meanwhile, for the spread of EV, charging installations are divided into general charging type and quick charging type. Also, charging amount and time are main factors to decide charging pay. But, because the opportunity coast for the charging time varies depending on the private situations, it is very important to understand exact phenomenon for the spread of EV charging installations and charging pay policy. Therefore this paper suggested the choice model of charging installation and time value in various situations by using Logit model to make clear the relationship between a choice of charging installation, charging time and willingness to pay for charge.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.10
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• pp.910-916
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• 2015

A sensorless motor control scheme with conventional back-Electro Motive Force (EMF) sensing based on zero crossing point (ZCP) detection has been widely used in various applications. However, there are several problems with the conventional method for effectively driving sensorless brushless motors. For example, a phase mismatch of 30 degrees occurs between the ZCP and commutation time. Additionally, most of the motor speed/current controls are achieved based on a pulse width modulation (PWM) method, which generates significant noise that distracts the back-EMF sensing. Due to the PWM switching, the ZCP is not deterministic, and thus the efficiency of the motor is reduced because the phase transition points become uncertain. Moreover, the motor driving performance is degraded at a low speed range due to the effect of PWM noise. To solve these problems, an improved back-EMF detection method based on a differential line method is proposed in this paper. In addition, the proposed sensorless BLDC driver addresses the problems by using a variable voltage driver generated from a buck converter. The variable voltage driver does not generate the PWM switching noise. Consequently, the proposed sensorless motor driver improves 1) the signal-to-noise ratio of back-EMF, 2) the operation range of a BLDC motor, and 3) the torque characteristics. The proposed sensorless motor driver is verified through simulations and experiments.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.5
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• pp.421-426
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• 2015

Need to develop human body's posture supervised robots, gave the push to researchers to think over dexterous design of exoskeleton robots. It requires to develop quantitative techniques to assess human motor function and generate the command to assist in compliance with complex human motion. Upper limb rehabilitation robots, are one of those robots. These robots are used for the rehabilitation of patients having movement disorder due to spinal or brain injuries. One aspect that must be fulfilled by these robots, is to cope with uncertainties due to different patients, without significantly degrading the performance. In this paper, we propose chattering free sliding mode control technique for this purpose. This control technique is not only able to handle matched uncertainties due to different patients but also for unmatched as well. Using this technique, patients feel active assistance as they deviate from the desired trajectory. Proposed methodology is implemented on seven degrees of freedom (DOF) upper limb rehabilitation robot. In this robot, shoulder and elbow joints are powered by electric motors while rest of the joints are kept passive. Due to these active joints, robot is able to move in sagittal plane only while abduction and adduction motion in shoulder joint is kept passive. Exoskeleton performance is evaluated experimentally by a neurologically intact subjects while varying the mass properties. Results show effectiveness of proposed control methodology for the given scenario even having 20 % uncertain parameters in system modeling.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.230-235
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• 2001

There are more than 15 millions cars or motors in Taiwan. According to the statistics from Environmental Protection Administration, the number of resulting scrap tires are near 110 thousand tons each year. The tire recycle programs in Taiwan were first conducted in 1989 and executed by ROC Scrap Tire Foundation. However, the current efficiency of the tire recycling industry still needs to be improved to minimize the environmental problem or fire hazards caused by scrap tires storage. Ten major tire-recycling factories are surveyed in this study. The investigations include the source of scrap tire, the shredding process, the market of products, the management of wastes disposal, and the difficulties of these sectors. As the varieties of the shredding machines of the recycle factories, there are three kinds of final products which include powder, granular, and chips. The wastes, wires and fibers, produced by the shredding process are the major problems fur all the factories. The percentage of the wire and fiber removal from rubbers still needs to be increased. The best approaches found in this study to increase the efficiency of scrap tire recycling processes are proposed which include the improvement of magnetic separation system fiber/rubber separation system and the minimization of waste disposal. A categorized standard of the processing outputs is suggested as a reference for the decision-making of the tire-recycling factories.

• Korean Journal of Agricultural Science
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• v.47 no.1
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• pp.43-58
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• 2020

Mulching plastic is used for the purpose of maintaining soil temperature, moisture, and weed and pest prevention in agriculture. Any remaining plastic after use may contaminate the soil and damage crop growth. To solve this problem, mulching plastic wrappers have been studied and developed, but the actual use rate is quite low due to their poor performance and frequent tearing of the plastic on the field. In this study, we developed a tractor attachable mulching plastic wrapper to minimize the tearing of the mulched plastic. The developed mulching plastic wrapper consists of hydraulic motors and pumps, valves, a microcontroller, and sensors. The collecting speed of the plastic mulch was calculated considering the tractor's travel speed and the radius of the collecting drum. A proportional controller was designed to control the rotating speed of the hydraulic motor as the plastic was wound around the collection drum and the radius increased. The performance of an indoor experiment was quite promising because the difference between the collecting speed predicted by the calculation and the actual collecting speed was 2.71 rpm. Based on a field verification test, the speed difference was max. 14.28 rpm; thus, the, proportional integral derivative (PID) controller needs to be considered to control the drum speed precisely. Another issue was found when the soil covered at the edge of the plastic was hardened or the road surface was uneven, the speed control was unstable, and the plastic was torn. In future research, vibrational plows will be equipped to break-up the harden soil for collecting the plastic smoothly.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.3
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• pp.292-300
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• 2011

Control systems in machinery equipment provide correction signals to motion units in order to reduce or cancel out the mismatches between sensor feedback signals and command or desired values. In this paper, we introduce a simulator for control characteristics of machinery equipment. The purpose of the simulator development is to provide mechanical system designers with the ability to estimate how much dynamic performance can be achieved from their design parameters and selected devices at the designing phase. The simulator has a database for commercial parts, so that the designers can choose appropriate components for servo controllers, motors, motor drives, and guide ways, etc. and then tune governing parameters such as controller gains and friction coefficients. The simulator simulates the closed-loop control system which is built and parameter-tuned by the designer and shows dynamic responses of the control system. The simulator treats the moving table as a 6 degrees-of-freedom rigid body and considers the motion guide blocks stiffness, damping and their locations as well as sensor locations. The simulator has been under development for one and a half years and has a few years to go before the public release. The primary achievements and features will be presented in this paper.

• Journal of Power System Engineering
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• v.20 no.6
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• pp.27-33
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• 2016

BLDC motors have the strong point of allowing high-efficiency operation, yet with the weak point of requiring position information for operation. Moreover, there have recently been frequent cases where the product differentiation of even a cheap BLDC motor demanded a high level of control performance similar to that of a controller using a high-precision position sensor. This paper proposes low cost position sensor that enables the acquisition of rotor position information based on index and incremental PWM, using a single position sensor instead of an expensive incremental encoder or a cheap 3 phase hall sensor. The characteristic of the proposed encoder is that index information at every $60^{\circ}$ of electrical angle is inscribed on the encoder disk, as well as a multiple number of values representing information about PWM, which is obtained by modulating information about the electrical angle of the rotor that has the resolution of $60^{\circ}$. Such a method has the characteristic of enabling the acquisition of high-precision position information based on the information about a multiple number of PWM waveforms and counter values that have all been inscribed on the encoder disk for each $60^{\circ}$ range. The feasibility of the proposed new encoder was verified by fabricating a prototype encoder generating 240 pulses, followed by confirming its performance using Micom's capture and software counter functions.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.764-769
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• 2004

The DC Motor in a vehicle may cause noise and vibration because of high speed revolution, which can make a driver feel uncomfortable. There have been various studies attempting to solve these problems, focusing mostly on the causes of and ways to reduce noise and vibration. It is suggested that the noise in a DC Motor may be primarily due to interaction between a brush and a commutator. Brush noise, the most common noise in a DC Motor, results from a brush bounced from the surface of the commutator, fluctuation of the friction between the brush and the commutator, and the impact on the brush when passing over slots of the commutator. Based on the noise test, one of the most important design parameters was shown to be the roundness of the commutator. As the DC motor is used, the roundness of the commutator gets bigger with subsequent increase of the level of brush noise and vibration. There must be a threshold in order to prevent the brush noise from getting worse. Using the method of CAE is more efficient than the real test for purposes of looking for various design parameters to maintain the roundness of the commutator. In this study, the design process to reduce the brush noise is presented with the use of a computer model. The design parameters to reduce the brush noise and vibration are proposed by using FEM. The design parameters are used to reduce the noise and vibration of a DC motor and it is verified with the test results on a fan DC motor in a vehicle. This method may be applicable to various DC motors.