• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.243-245
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• 2007

This paper presents the implementation of teleoperation control of an omni-direction mobile robot. The master joystick robot has two degrees of freedom to control the movement of the slave mobile robot in the Cartesian space. In addition, the whole teleoperated control system is closed by the force feedback. The operator can feel the contact force as the slave robot makes contact with the environment. Experimental results show that the teleooerated control with force feedback has been successfully implemented.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1673-1678
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• 2005

This paper addresses both theoretical and experimental studies of the stability of haptic interfaces during the simulation of virtual Coulomb friction. The first objective of this paper is to present an analysis of how friction affects stability in terms of the describing function method and the absolute stability theory. Two different feedback methods are introduced and are used to evaluate the analysis: an active force feedback, using a motor, and a passive force feedback, using controllable brake. The second objective of this paper is to present a comparison of the theoretical and experimental results. The results indicate that the sustained oscillations due to the limit cycle occur when simulating friction with an active force feedback. In contrast, a passive force feedback can simulate virtual friction without the occurrence of instability. In conclusion, a hybrid active/passive force feedback is proposed to simulate a highly realistic friction display.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1124-1127
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• 1996

Asymmetric cylinders are usually used as an actuator of active suspensions. Since the force is influenced not only by the control but by the road roughness, force control is needed to track the desired force. But the conventional error feedback control treats the valve-cylinder dynamics at its operating point and many use the symmetric model which differ in all respects. We adopt an asymmetric cylinder model and apply a feedback linearization method for the force control to compensate both the valve nonlinearities and the effects of the road roughness.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1523-1526
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• 1996

This paper presents a new method of force reflection in the teleoperated mobile robot control: artificial force feedback. Generally it is well known that force feedback from slave to master increases the reality with which the operator interacts with the environment. In the applications of the teleoperated mobile robot, however, such a force feedback control algorithm has rarely appeared in the literature because the contact force between the environment and the mobile robot is not available. In this paper, a method of artificially generating the feedback force for the teleoperated mobile robot is presented in order to improve the task performance. The computed artificial force feeds into the new designed joystick so as to increase the telepresence of the environment. Through simulations, we confirm the validity and effectiveness of our algorithm.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1998.10a
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• pp.286-294
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• 1998

This paper presents an experimental study on the performance of the active damper device by feedback variables. The damper is a mass-typed active device, which exerts the inertia control force on the building by AC servo motor. The control performance is experimentally analyzed considering the building response and the control force. It is found that the building response is greatly reduced by mass-typed device under the resonant and earthquake loading. Also, the experimental results show that the velocity feedback reduces the building responses with the smallest amount of control force than any other feedback variables.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.235-235
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• 2000

This paper proposes a tole force feedback control through internet systems. The system consists of joystick, solver, client, robot, and internet. The main contribution of this work is the implementation of the system rather than theoretical analysis. The time delay problems will be considered next step.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.486-489
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• 1996

The objective of this paper is to design a force feedback controller for bilateral control of a master-slave manipulator system. In a bilateral control system, the motion of the master device is followed by the slave one, while the force applied to the slave is reflected on the master. In this paper, a fuzzy logic controllers applied to the system. Using the fuzzy logic controller, the knowledge of the system dynamics is not needed. Simulations and experimental results show the performance of the proposed controller.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.8
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• pp.801-806
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• 2014

LAS (Laparoscopy Assisted Surgery) has been substituted alternatively for traditional open surgery. However, when using a commercialized robot assisted laparoscopic such as Da Vinci, surgeons have encountered some problems due to having to depend only on information by visual feedback. To solve this problem, a haptic function is required. In order to realize the haptic teleoperation system, a force feedback and bilateral control system are needed. Previous research showed that the perturbation value estimated by a SPO (Sliding Perturbation Observer) followed a reaction force that loaded on the surgical robot instrument. Thus, in this paper, the force feedback problem of surgical robots is solved through the reaction force estimation method. This paper then introduces the possibility of the haptic function realization of a laparoscopic surgery robot using a bilateral control system. For bilateral control, the master uses an impedance control and the slave uses a SMC (Sliding Mode Control). The experiment results show that a torque and force sensorless teleoperation system can be implemented using a bilateral control structure.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.140-144
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• 1990

On force control of robot, the transient response of the force is as important as the steady state value. We analyze the force for an 1 d.o.f. model. Based on the analysis, we finds out a desirable condition of the control system parameters for stability of the force. We propose a force rate feedback control for implementation. Through experiments we shows that the force can be controlled stably for an arbitrary environment.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.418-429
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• 2018

This paper studies the decentralized position/force control problem for constrained reconfigurable manipulator without torque sensing. A novel joint torque estimation scheme that exploits the existing structural elasticity of the manipulator joint with harmonic drive model is applied for each joint module. Based on the estimated joint torque and dynamic output feedback technique, a decentralized position/force control strategy is presented. In order to solve the problem of controller parameter perturbation, the non-fragile robust technique is introduced into the dynamic output feedback controller. Subsequently, the stability of the closed-loop system is proved using the Lyapunov theory and linear matrix inequality (LMI) technique. Finally, two 2-DOF constrained reconfigurable manipulators with different configurations are applied to verify the effectiveness of the proposed control scheme in numerical simulation.