• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.108.4-108
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• 2001

The integrated environment for the fuzzy logic controller with the acceleration converter to improve the dynamic characteristic of a one-axis moving table is proposed in the paper. The two inputs of the fuzzy logic controller are position error and velocity. The two inputs of the acceleration converter used to produce the acceleration input for the one-axis moving table are actual and setting rotational speeds. The proposed controller is implemented on a personal computer by using MATLAB and Visual Basic for a real time control via a motion control board. The position control results when the stair input is applied to control the position of the one-axis moving table, are shown. The experimental results of the proposed position control system are compared to the conventional PID ...

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.921-927
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• 1988

The process and results of computer simulation using bond graphs for a hydraulic system driving large rotational inertia are presented in this paper. As the large rotational inertia and its application characteristics, control criteria of this system is not position-control nor velocity-control but appropriate acceleration, deceleration and inching ability. All the components' nonlinear characteristics are modelled using bond graphs. The equationing and solution process is carried out by a package. Finally it is concluded that modelling of this kind of system by bond graphs and using a software as its solver shows good approximated results to actual experimental data, and that the proposed modelling may be useful to actual design process for this kind of hydraulic system.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2116-2119
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• 2005

Inverted pendulum is a classical example and a famous tool for testing the effectiveness of many control schemes. Owing to their nonlinearity and unstable characteristic, a controller development either for swinging-up or stabilizing its upright position had been a great interest of many researchers. In this paper, the swinging-up control of the inverted pendulum using energy control will be presented. However, the saturation function in its control law could harm the experimental equipments. In addition, this swinging-up method did not consider limited sector of the arm angle to avoid another hazard, for instance, the twisted cable in the apparatus. Therefore, in this paper the position control of the arm angle using simple PD control in accordance with the energy control is proposed. Consequently, the limited arm sector angle can be achieved and the saturation function can also be replaced effectively by the PD control.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.743-746
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• 1996

A hybrid control scheme to regulate the force and position by dual arms is proposed, where two arms are treated as one arm in a kinematic viewpoint. Our approach is different from other hybrid control approaches which consider robot dynamics, in the sense that we employ a purely kinematic based approach for hybrid control, with regard to the nature of position-controlled industrial robots. The proposed scheme is applied to sawing task. In the sawing task, the trajectory of the saw grasped by dual arms is planned in an offline fashion. When the trajectory of the saw is planned to follow a line in a horizontal plane, 3 position parameters are to be controlled(i.e, two translational positions and one rotational position). And a certain level of contact force has to be controlled along the vertical direction(i.e., minus z-direction) not to loose the contact with the object to be sawn. Typical feature of sawing task is that the contact position where the force control is to be performed is continuously changing. Therefore, the kinematic mapping between the force controlled position and the joint actuators has to be updated continuously. The effectiveness of the proposed control scheme is experimentally demonstrated. The proposed hybrid control scheme can be applied to arbitrary dual arm systems, regardless of their kinematic structure and the number of actuated joints.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.5
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• pp.599-605
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• 2011

A 3-D rehabilitation robot system is developed. The robot system is for the rehabilitation of upper extremities, especially the shoulder and elbow joints, and has 3-D workspace for occupational therapy to recover physical functions in activities of daily living(ADL). The rehabilitation robot system 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. In this paper, a hybrid position/force controller is used for controlling positions and forces simultaneously The controller is tuned according to the robot posture. The active motion modes for rehabilitation program consist of active-resisted motion mode and active-free motion mode. The results of the experiments show that the proposed motion modes provide the intended forces effectively.

• Journal of Drive and Control
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• v.16 no.3
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• pp.23-32
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• 2019

This study proposed a fault tolerant control algorithm for electro-hydraulic brake systems where permanent magnet synchronous motor (PMSM) drive is adopted to boost the braking pressure. To cope with motor position sensor faults in the PMSM drive, a braking pressure controller based on an open-loop speed control method for the PMSM was proposed. The magnitude of the current vector was determined from the target braking pressure, and motor rotational speed was derived from the pressure control error to build up the braking pressure. The position offset of the pump piston resulting from a leak in the hydraulic system is also compensated for using the open-loop speed control by moving the piston backward until it is blocked at the end of stroke position. The performance and stability of the proposed controller were experimentally verified. According to the results, the control algorithm can be utilized as an effective means of degraded control for electro-hydraulic brake systems in the case that a motor position sensor fault occurs.

• Korean Journal of Applied Biomechanics
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• v.15 no.2
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• pp.1-10
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• 2005

G. B. LEE, A. S. GWON, The Research for Using methodof GRF (Ground Reaction Force) on Rotational Movement in Arabesque. Korean Journal of Sport Biomechanics, Vol. 15, No. 2, pp.1-10, 2005. As, in relation to all movements of a human being, the movements such as mutually walking, running, rotating, and jumping are attained endlessly through the ground amid the interaction with the ground, in terms of the harmonious movement of the upper limbs and the lower limbs, related to the basic movement in ballet, the type of a movement depends on the size and direction of the force that presses down the ground (Fz, Fx, Fy) amid the interaction with the ground. Therefore, aiming to correctly and efficiently perform a rotational movement in Arabesque, this study analyzed factors of the force manifestation through GRF (Ground Reaction Force), by dividing into preparing, stepping, standing, rotating, and finishing stages (events (1) ${\sim}$ (5)), targeting the subjects of 4 elite female students who majored in ballet. 1. At the No.5 position of the preparing stage, It is necessary that support the ground with left and right foot balance, 2. As the stepping stage is the phase ranging from the event (2), in which a plie movement of bending a knee is started, to the event (3) of stretching a knee, Rebunding motion is not good, and One have a position with ankle and knee flextion condition in order to stretch strengthly in event (3) position 3. At the event (1) position, It is necessary that exert the Fz reaction force at the event (3) position. Because large stretch force help to have a toe on position easily and show a active motion 4. In order to have a stand and rotation motion smoothly, One need a muscle strength training for ankle extension, knee extension, control horizental force

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.8
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• pp.603-609
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• 2016

This paper presents an optimally designed master device mechanism for teleoperated interventional robotic system. The interventional procedures using the teleoperated robotic system and the physicians' requirements are summarized. The master device should implement 5-DOF motion including 2-DOF translational motion for the entry position control, 2-DOF rotational motion for the orientation control, and 1- DOF translational motion for needle insertion. The handle assembly includes a 1-DOF translational mechanism for needle insertion and buttons for operation mode selection. The mechanisms for the 2-DOF translational motion and the 2-DOF rotational motion are designed using motors and brakes based on the various mechanisms to satisfy all the above requirements, respectively. Absolute position sensors are adopted to implement automatic initial positioning and orientation matching at the first step of needle insertion.

• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.119-124
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• 2021

In a situation where Moore's law, which states that the performance of semiconductor integrated circuits doubles every two years, is showing a limit from a certain point, and it is difficult to increase the performance due to the limitations of exposure technology.In this study, a wafer hybrid method that can increase the degree of integration Various research on bonding technology is currently in progress. In this study, in order to achieve rotational precision between wafers in wafer hybrid bonding technology, modeling of θ_z alignment stage and VCM actuator modeling used for rotational alignment, magnetic field analysis and desgin, control, and evaluation are performed. The system of this study was controlled by VCM actuator, capactive sensor, and dspace, and the working range was ±7200 arcsec, and the in-position and resoultion were ±0.01 arcsec. The results of this study confirmed that safety and precise control are possible, and it is expected to be applied to the process to increase the integration.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.1
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• pp.44-52
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• 1994

Load simulator is essential to test and quality the performance of various control systems. It is good time to introduce a method to design and analyze the load simulator or since many research centers and industrial companies are trying to buy or design the load simulator. The stability, accuracy and response speed of the simulator are represented by the system parameters such as the hydraulic motor characteristics, the servovalve characteristics, supply pressure, rotational inertia, rotational spring constant, sensor and controller gains. Two design examples are shown here. A load simulator for a position control system and that for a velocity control system are designed. The goodness of the proposed method is verified by the digital computer simulations.