• Journal of the Semiconductor & Display Technology
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• v.21 no.4
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• pp.126-131
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• 2022

The number of joint disease patients is increasing every year. Currently, the most CPM(Continuous Passive Motion) equipment uses expensive imported equipment, and one CPM equipment is designed to be used only in one joint, medical personnel or hospitals who are the main users of the medical equipment need to have several types of CPMs for joint rehabilitation. To solve this problem, this paper designed a multifunctional joint medical equipment that enables rehabilitation of knee, shoulder, and elbow joints in one CPM equipment and includes general, intensive, and adaptive exercise functions for effective treatment according to the patient's condition. The patient's condition was diagnosed using a load cell and a current sensor. In this paper, effective rehabilitation methods were presented and high reliability and precision of medical equipment was confirmed through experiments using potentiometer, encoder, and PI controller.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.11
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• pp.3066-3074
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• 1994

This paper addresses the residual vibration problem of robots due to joint flexibility excited by fast accelerations, which has not been easily solved with conventional closed loop controllers. In this paper, an open loop input shaping technique, proposed by singer, has been applied to a 3 DOF robot with joint flexibility. In conjunction to the technique, a closed loop controller based on time-delay controller was also used. The results of simulations and experiments showed that the technique is quite effective for suppressing the residual vibration.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.101-106
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• 1997

This paper proposes a stable adaptive neural network control(NNC) for fixable joint manipulators. For designing the stable adaptive NNC, the flexible system dynamics is separated into fast and slow subdynamics according to singular perturbation concept. For the slow subdynamics, an adaptive NNC is designed to warrant the system stability and NN learning by lyapunov stability criterion. And to stabilize the fast dynamics, derivative control loop is installed. Through numerical simulation, the performance of the proposed NNC was compared to that of an adaptive controller designed based on the knowledge of the system dynamics. The proposed NNC shows much improvement over the conventional adaptive controller.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.265-270
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• 2001

In this paper, a robust controller is proposed to control a robot manipulator which is governed by highly nonlinear dynamic equations. The controller is computationally efficient since it does not require the dynamic model or parameter values of a robot manipulator. It, however, requires uncertainty bounds which are derived by using properties of revolute joint robot dynamics. The stability of the robot with the controller is proved by using Lyapunov's direct method. The results of computer simulations also show that the robot system is stable, and has excellent trajectory tracking performance.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.2_1
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• pp.161-168
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• 2022

This study proposed a new approach to impliment a robusut control of comsumer-friendly flexible manipulator with five joint for untact working in filed work-site. The output redefinition approach was used to overcome the non minimum phase characteristic of the system. The new output is defined so that the zero dynamics related to this output are stable. The control strategy is based on an computed torque method which is applicable to a class of time-invariamt phase linear systems whose uncertainties appear in output loop stable. The controller is composed of a stabilizing joint controller and an output redefinition tracking controller. Experimental results are also presented to verify the effectiveness of the proposed control scheme.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.6
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• pp.1203-1211
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• 2017

This paper proposes a robust controller for flexible joint robots to achieve tracking performance and to improve robustness against both matched and mismatched disturbances. The proposed controller consists of a disturbance observer(DOB), passivity-based controller, and integral sliding mode controller(ISMC) in a backstepping manner. The DOB compensates the mismatched disturbance in the link-side and formulates the reference input for the motor-side controller. Interconnection and damping assignment passivity-based controller (IDA-PBC) performs tracking control of motor-side, and it is integrated to nominal control of ISMC to guarantee the over-all stability of the nominal system, while, matched disturbances are decoupled by the discontinuous control of ISMC. In the design of the link-side controller, PD type impedance controller is designed with DOB and this leads the continuous control input which is suitable to the reference input for the motor-side.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.4
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• pp.371-379
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• 2006

Increasing requirements for the high quality of industrial robot performance made the vibration control issue very important because the vibration makes it difficult to achieve quick response of robot motion and may bring mechanical damage to the robot. This paper presents a vibration control solution for industrial robots which have flexible joints. The joint flexibility is modeled as a two-mass system. And we analyze the vibration problem of a classical P-PI controller when it used for the flexible joints of industrial robots. Then a state feedback controller is designed for vibration suppression of the two-mass system. Finally, a gain-scheduling method is designed for maintaining control performance in spite of the time-varying nature of each joint's load side inertia. Simulation and experimental results show effective vibration suppression and uniform properties in overshoot in spite of the variation of load. The result of this study can be applied to the appropriate gain manipulation of many other mechatronic devices which have the two-mass system with varying load side inertia.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.12
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• pp.1160-1166
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• 2015

This paper proposes a decentralized robust adaptive control scheme for robot manipulators with input torque saturation in the presence of uncertainties. The control system should consider the practical problems that the controller gain coefficients of each joint may be nonlinear time-varying and the input torques applied at each joint are saturated. The proposed robot controller overcomes the various uncertainties and the input saturation problem. The proposed controller is comparatively simple and has no robot model parameters. The proposed controller is adjusted by the adaptation laws and the stability of the control system is guaranteed by the Lyapunov function analysis. Simulation results show the validity and robustness of the proposed control scheme.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.2 no.2
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• pp.139-145
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• 2002

In this paper, we proposed an intelligent digital redesign method for a class of fuzzy-model-based controllers, effective fur stabilization of continuous-time nonlinear systems. The TS fuzzy model is used to expend the results of the digital redesign technique to nonlinear systems. The proposed method utilized the recently developed LMI technique to obtain a digitally redesigned fuzzy-model-based controller. The intelligent digital redesign problem is converted to equivalent problem, and the LMI method is used to find the digitally redesigned fuzzy-model-based controller. The stabilization conditions of TS fuzzy model are derived for stabilization in the sense of Laypunov stability. In order to demonstrates the effectiveness and feasibility of the proposed controller design methodology, we applied this method to the single link flexible-joint robot arm.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.346-350
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• 1989

This paper concerned about a study on the position control of KED-1 robot manipulator using PID self-tuning controller. For two joint manipulator KED-1, KED-1 manipulator is translated into kinematics to control each joints in joint space seheme. Angle displacements of joint coordinate are transformed into reference angle velocity of each subsystem through trajectory planning. Also, time sharing technique is used to control KED-1 manipulator. A series of simulation and experiment are performed for each joint in show the valid of proposed algorithm.