• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.4
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• pp.101-107
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• 2009

Actuators using shape memory alloys use the one-way shape recovery stress. But when external load is applied the accumulated plastic strain induced by repeated deformation is the factor of generation of uncorrect recovery stress and unreliability. To solve this problem, two-way shape memory effect (TWSME) is considered. TWSME induced by plastic deformation have advantages including simple heating cycle without external force and enough recovery force for using actuators. but there is no research on cylinder-type or tube-type shape memory alloy actuators using two-way shape memory effect until now. Therefore in this study, characteristics of two-way shape memory effect is verified through the compression experiments using cylinder-type and tube-type specimens.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.4
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• pp.64-71
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• 2009

A 3-D rehabilitation robot system is developed in this paper. The robot system is for the rehabilitation of upper extremities, especially the shoulder and elbow joints, and has 3-D workspace for enabling occupational therapy to recover physical functions in activities of daily living(ADL). The rehabilitation robot system, which is driven by actuators, has 1 DOF in horizontal rotational motion and 2 DOF in vertical rotational motion, where all actuators are set on the ground. Parallelogram linkage mechanisms lower the equivalent inertia of the control elements as well as control forces. Also the mechanisms have high mechanical rigidity for the end effector and the handle. Passive motion mode experiments have been performed to evaluate the proposed robot system. The results of the experiments show and excellent performance in simulating spasticity of patients.

• International Journal of Automotive Technology
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• v.7 no.2
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• pp.161-166
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• 2006

This paper presents shift characteristics of a dual clutch transmission(DCT). To obtain the shift force, dynamic models of the DCT are constructed by using MATLAB/Simulink and considering the rotational inertia of every component and the target pre-select time. Dynamic models of the shift and clutch actuators are derived based on the experimental results of the dynamic characteristics test. Based on the dynamic model of the DCT synchronizer, control actuator and vehicle model, a DCT vehicle performance simulator is developed. Using the simulator, the shift force and speed of the relevant shafts are obtained. In addition, the torque and acceleration of actuators are calculated during the shift process by considering the engaging and disengaging dynamics of the two clutches. It is observed from the performance simulator that uninterrupted torque can be transmitted by proper control of the two clutches.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.3
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• pp.369-375
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• 2010

The two-dimensional finite element formulation for the basic field equations governing electrochemical responses of ionic conducting polymer-metal composite(IPMC) actuators is proposed in the present study. Biaxial deformation of a platinum plated Nafion actuator having 4 electrodes is dominated by electro-osmosis of hydrated ions and self-diffusion of free water molecules. Some numerical studies for IPMC actuators with electric field are carried out in order to show the validity of the proposed formulation and electric field analysis for the initial condition of total charge distribution are conducted using commercial code ANSYS/Emag.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.382-385
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• 2003

In this paper, in order to improve the control performance of piezoelectric actuator, an integrated control structure is proposed. The control structure consists of inverse hysteresis model , to compensate the hysteresis nonlinearty problem, and feedforward - feedback controller to give a good tracking performance. The inverse hysteresis model and neural network are used as feed-forward controller, and PID controller is used as a feedback controller. From diverse experiments it is concluded that the proposed control scheme gives good tracking performance than the classical control does.

• Journal of the korean Society of Automotive Engineers
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• v.11 no.6
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• pp.68-79
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• 1989

Dynamic characteristics for an automotive V-belt CVT with centrifugal and torque-ramp actuators was investigated by bondgraph modeling method. Ten(10) state space equations for the V-belt CVT were developed from the constructed bondgraph model and linearized for perturbation at steady state. As simulation results, speed ratio versus time curves were obtained. It was found that as the ratio of the moment of inertia of the pulleys increased, the stability of the V-belt CVT system decreased. Change in the ratio of the spring constants caused the magnitude of the change of the speed ratio, but had little effect on the settling time of the system became faster and the stability of the system improved. However, the sensitivity of the speed ratio decreased with the increasing .betha.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.5
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• pp.105-111
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• 2003

The three-axis road simulator is the test equipment which can simulate the standardized road conditions for the durability evaluation of automotive components such as suspensions. The road load data are collected and acquired from a vehicle test, and then these data are used to simulate road load conditions by the road simulator which consists of hydraulic actuators, link mechanism and servo controller. The link mechanism must be designed in consideration of the dynamic effect and interference during three axes motions in order to generate accurate motions. In this paper, the structural and kinematic analysis of the link mechanism is performed, and these results can be used for developing the three-axis road simulator. The three-axis road simulator provides considerable savings in cost, development time, and testing risk during developing automotive components.

• International Journal of Automotive Technology
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• v.7 no.6
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• pp.687-695
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• 2006

This paper presents a network-based traction control system(TCS), where several electric control units(ECUs) are connected by a controller area network(CAN) communication system. The control system consists of four ECUs: the electric throttle controller, the transmission controller, the engine controller and the traction controller. In order to validate the traction control algorithm of the network-based TCS and evaluate its performance, a Hardware-In-the-Loop Simulation(HILS) environment was developed. Herein we propose a new concept of the HILS environment called the network-based HILS(Net-HILS) for the development and validation of network-based control systems which include smart sensors or actuators. In this study, we report that we have designed a network-based TCS, validated its algorithm and evaluated its performance using Net-HILS.

• Journal of Sensor Science and Technology
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• v.30 no.2
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• pp.88-93
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• 2021

In this paper, a folding sensor based on capacitance is proposed. The sensor was developed to sense the length and angle data for the milli-scale actuators without causing any interference to the actuating joints. For the sensing and testing the robotic joint with reducing the cost and complexity aspects of manufacturing, a simple composition was adopted. The sensor comprises a pair of copper tapes, papers, and wires. The complete sensing unit is constructed by bonding the tapes with the papers and soldering the wire to the copper parts. For accuracy, a teensy 4.0 board, which has a 12-bit ADC resolution, is employed. Furthermore, the sensed analog data is not translated into the unit of capacitance for accuracy; however, it is filtered using a low-pass filter and subsequently, a Butter-worth filter. The data obtained demonstrate a periodic waveform, which implies that the data are in good agreement with the hypothesis set prior to the experiments. Compared to other milli-scale sensors, this could be a better option for sensing the length and angle data for milliscale actuators.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.1-7
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• 2012

The brake-by-wire technology is a new automotive chassis system that allows standard braking operations by electronic components with lighter weights and faster response. The brake-by-wire units such as EMB (Electro-Mechanical Brake) are controlled by electronic sensors and actuators and, thus, the fault diagnosis is essential for implementation. In this study, a model-based fault diagnosis system is developed for the sensors based on the analytical redundancy method. The fault detection algorithm is verified in simulations for various faulty cases. A test bench is built including the EMB unit and the performance of the proposed fault diagnosis system is evaluated through the experiment.