• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.511-516
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• 1991

A new end-effector has been devised and the problems resulted from using it with SCARA robots are discussed. The end effector has two modules: one composed of two ultrasonic motors and two encoders for controlling each finger, and the other module composed of two ultrasonic motors and two encoders for controlling the wrist. The wrist module adds two degrees of freedom to the SCARA type robot, which generally has four degrees of freedom. With independent finger actuation and touch sensors, the gripper under computer control can feedback information about part size and part presence. Ultrasonic motors with high torque and slow motion characteristics are used. The principle of ultrasonic motors is explained and the servo characteristics of ultrasonic motors are studied. They are controlled by the general motion controller (Hewlett Packard HCTL-1000) which is linked to an IBM-PC AT.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.917-921
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• 1991

Hydraulic fitting impulse tester is equipment which produce impulse pressure waveform that specified foreign standard of SAE, JIS etc. Test conditions of SAE J1453 about waveform standard indicates frequency of 35-70 cycle/min, pressure of 560 bar, oil temperature of 93 .+-.3.deg. C etc. and required cycle is a million over. In additions, Test condition operated continuously equipment. This development item adopted new pattern method such as intensifier and rotary distributor is different from already established fitting impulse tester applied servo valve and high pressure direct directional control valve. Therefore, this development item which compares already established item is good reliability, low cost of manufacture and save of electric energy. especially, Domestic small and medium enterprise uses this tester because of economical cause. We develope appropriateness tester which conforms to demand of user.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.504-510
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• 1991

SAMSUNG Electronics has developed a SCAR.A robot system, SM3, which is applicable to several assembly, inspection, and adjustment tasks. This robot system drives by AC servo motors has attained a .theta.1 and .theta.2 axis maximum composite speed of 5.4 m/sec, a repeatability of .+-.05 mm, and a cycle time of 1.2 sea. The robot controller based on three 8086 and one 8087 processors consists of the main controller, the joint position controller, and the motor controller. The robot controller has plentiful self-diagnosis and control capabilities, and can be interfaced to other external device. The robot language FARAL Is designed such that every task is easily programmed. In this paper, the main features of the body, controller, and FARAL of SM3 will be described. In particular, the control method designed for a stable and fast robot motion will be explained. Finally, the future development will be addressed.

• Journal of Mechanical Science and Technology
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• v.15 no.7
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• pp.831-838
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• 2001

Torque ripple control of brushless DC motor has long been the main issue of the servo drive systems in which the speed fluctuation, vibration and acoustic noise need to be minimized. The vast majority of the methods for suppressing the torque ripple require the Fourier series analysis and either the iterative or least mean square minimization. In this paper, a novel approach based on the d-q-0 reference frame that achieves ripple-free torque control with maximum efficiency is presented. The proposed method optimizes the reference phase current waveforms including even the case of 3-phase unbalanced condition, and the motor winding currents are controlled to track the optimized current waveforms by the delta modulation technique. As a results, the proposed approach provides a simple and yet effectine means for obtaining the optimal motor excitation currents. The validity and applicability of the proposed control scheme are verified through simulations and experimental investigations.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.686-691
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• 2001

In this paper, the pneumatic service robot with a hybrid type is developed. A pneumatic has the advantage of good compliance, high payload-to-weight and payload-to-volume ratios, high speed and force capabilities. Using pneumatic actuators which have low stiffness, the service robot can guarantee safety. By suggesting a new serial-parallel hybrid type for the service robot which separates into positioning motion and orienting motion, we can achieve large workspace and high strength-to-moving-weight ratio at the same time. A sliding mode controller can be designed for tracking the desired output using the Lyapunov stability theory and structural properties of pneumatic servo systems. Through many experiments of circular trajectory, the pneumatic service robot is evaluated and verified.

• Journal of Broadcast Engineering
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• v.25 no.3
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• pp.428-438
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• 2020

The jitter in the digital videos lowers the visibility and degrades the efficiency of image processing and image compressing. In this paper, we propose a video stabilizer architecture based on triplet CNN and a method of synthesizing training datasets based on video synthesis. Compared with a conventional deep-learning video stabilization method, the proposed video stabilizer can reduce wobbling distortion.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.6
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• pp.106-113
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• 1997

A new algorithm based upon TDC (Time Delay Control) is proposed to improve the robustness of TDC performance in systems where the stick-slip friction is strong. Experiments were performed at the different levels of friction. The reponses of the TDC and the modified TDC were compared each other, and against those of a PID controller with an anti-windup. The results show that the TDC and the modified TDC equally perform better than the PID, and that the modified TDC performs consistently well even with variations in the friction level while the TDC does not.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.652-657
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• 1992

This paper presents to accomplish successfully a multi-input real time control by applying control hierarchy for sliding mode of multi-joint manipulators whose nonlinear terms are regarded as disturbances. We- could simplify the dynamic equations of a manipulator and servo system, which are composed of linear elements and nonlinear elements, by assuming that nonlinear terms, which are Inertia term, gravity force term, Coriolis force term and centrifugal force term, are external disturbance. By simplifying that equation, we could easily obtain a control input which satisfy sliding mode of multi-input system. We proposed a new control input algorithm in order to decrease chattering by changing control input according as effect of disturbance if a control response become within allowance error range. In this experiments, we used DSP(Digital Signal Processor) controller to suppress chattering by time delay of calculation and to carry out real time control.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.382-386
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• 1992

In this paper, the author proposed FLVSC(Fuzzy Logic Variable Structure Controller), of which control rules are extracted from the concepts of VSC(Variable Structure Control). FLC(Fuzzy Logic Controller) based on linguistic rules has the advantages of not needing of some exact mathematical model for plant to be controlled. The proposed method has the characteristics which are viewed in conventional VSC, e.g. insensitivity to a class of disturbances, parameter variations and uncertainties in sliding mode. In addition, the method has the properties of FLC - noise rejection capability etc. The computer simulations have been carried out for a DC servo motor to show the usefulness of the proposed method and the effects of disturbances and parameter variations are considered.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.306-311
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• 1992

We propose software algorithms which provide the characteristics of acceleration/deceleration essential to high dynamic performance at the transient state where industrial robots or CNC machine tools start and stop. The path error, which is one of the most significant factors in performance evaluation of industrial robots and CNC machine tools, is analyzed for linear, exponential, and parabolic acceleration/deceleration algorithms in case of circular interpolation. The analysis shows that the path error depends on the acceleration/deceleration routine and the servo control system. In experiments, the entire control algorithm including the proposed acceleration/deceleration algorithms is executed on the motion control system with a floating point digital signal processor(DSP) TMS320C30 as a CPU. The experimental results demonstrate that the proposed algorithms are very effective in controlling axes of motion of industrial robots or CNC machine tools with the desired characteristics.