• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.507-512
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• 1992

This paper presents a method for the automatic generation of assembly sequences based on the recursive extraction of a preferred part along with the verification of its disassemblability. To verify the disassemblability of the part we inference the geometric precedence constraints using a method of extracting separable directions for the part and determine the disassemblability cost by the separability and stability cost. The proosed method provides a local optimal solution of finding a cost effective assembly plan, and the feasibility of calculating robot motion programs by evaluating separable directions in flexible manufacturing application. A case study is given to illustrate the concepts and procedure of the proposed scheme.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.618-623
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• 1992

In this paper robotic manipulators in which the joints exhibit a certain amount of elasticity are considered. Based on a feedback linearized model, sliding mode control system is designed. In the control system design, weak joint stiffness assumption does not needed. Simulation results are presented to verify the validity of the control scheme. A robustness analysis for a feedback linearized model is also given with respect to uncertainties on the robot parameters.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.974-979
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• 1990

The system discussed in this paper is an integrated stand-alone system with the full functional capabilities required of a telerobot system. It is complete with a force-reflecting 6-DOF hand controller, driving a PUMA 560 or 762 robot, with an integrated force-torque sensing wrist sensor and servo-driven parallel jaw gripper. A mix of custom and standard electronics, distributed computers and microprocessors, with embedded and downloadable software, have been integrated into the system, giving rise to a powerful and flexible teleautonomous control system.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.252-257
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• 1990

For the position control of BL-DC motors, 2.phi.-3.phi. conversion unit, hysteresis band device, and PWM pulse generation are required. By utilizing a single-chip processor INTEL 8097BH, we cover all required functions. As a result, no analogue device is employed in this control scheme, so that it makes BL-DC motor controller simple and flexible. Furthermore, the single-chip processor is utilized for the nonlinear coordinate transformation which is necessary for the linearization of the motor system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.04a
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• pp.213-217
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• 1993

This paper presents an end-point of 1-link flexible robot arm with a tip-mass by using self-turning fuzzy algorithm. The arm is mounted on a translational mechanism driven by a ballscrew, whose rotation is controlled by CD servomotor. Tip position is controlled so that it follows a desired position. A feedback signal is composed of both the tip-displacement error and change in error. This paper gives the experimental tip responses according to the variations of tip-mass and beam-length, and also showes the effects of reducing the residual vibrations occuring at the end-point.

• Journal of the Korean Institute of Navigation
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• v.23 no.4
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• pp.97-104
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• 1999

본 논문은 퍼지신경망을 이용한 유연성 단일 링크 로봇 매니퓰레이터의 위치제어에 관한 논문이다. 제안된 퍼지신경망 모델은 전건부와 결론부에 퍼지집합을 갖는 퍼지규칙으로 구성된 퍼지모델을 표현하고, 퍼지추론을 수행하는 기능을 가진다. 유연성 로봇 매니퓰레이터에 대한 동적모델을 유도하고, 시뮬레이션을 통해 PID 제어기와 비교 분석하였다. 그 결과 제안된 제어기가 PID 제어기보다도 개선된 성능을 확인하였다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.5
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• pp.488-497
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• 1984

In the assembling process by industrial robots, many difficulties stem from the fact that the assembly operation is impossible or the parts to be assembled can be damaged by reaction forces due to even little misalignment in part mating. In this paper a flexible and sensible robot wrist is developed to make possible the precision insertion operation. The flexibility of the developed wrist were evaluated both analytically and experimentally in actual insertion process. The results show that without the use of feedback control the wrist is capable of doing insertion operations with a small clearance at a low inserting force. For smaller clearance the assembly process was devised involving insertion force feedback and a control algorithm for this active accommodation was developed. The simulation results show that if the active feedback control is used the insertion action can be performed with much less force, as compared with a passive accommodation method.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.3
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• pp.318-323
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• 2005

In this paper, we propose a systematic method of a fuzzy-model-based controller for continuous-time nonlinear dynamical systems which may contain uncertainties. The continuous-time uncertain TS fuzzy model is first constructed to represent the uncertain nonlinear system. A parallel distributed compensation (PDC) technique is then used to design a fuzzy model based controller for both stabilization and tracking. Finally, the designed continuous-time controller is converted to an equivalent discrete-time controller by using an intelligent digital redesign method. This new design technique provides a systematic and effective framework for integration of the fuzzy model based control theory and the advanced digital redesign technique for nonlinear dynamical systems with uncertainties. Finally, the single link flexible-joint robot arm is used as an illustrative example to show the effectiveness and the feasibility of the developed design method.

• Transactions of the KSME C: Technology and Education
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• v.5 no.2
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• pp.89-95
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• 2017

LCD robot vertical frame lets a arm assembly with glass substrate move up and down, so it must have high stiffness and strength. We applied new manufacturing process by using design optimization process such as topology and size optimization in order to satisfy the request of high stiffness and light weight. The proposed model should be evaluated for endurance strength. Therefore fatigue assessment for weak point of aluminum welding area of vertical frame studied with hot spot stress approach. And the actual stress measuring from test was compared and evaluated with the dynamic stress calculated from multi-body dynamics considering flexible body.

• Structural Engineering and Mechanics
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• v.62 no.5
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• pp.619-629
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• 2017

This paper focuses on the study of complete dynamic modeling and maximum dynamic load carrying capacity computation of N-flexible links and N-flexible joints mobile manipulator undergoing large deformation. Nonlinear dynamic analysis relies on the Timoshenko theory of beams. In order to model the system completely and precisely, structural and joint flexibility, nonlinear strain-displacement relationship, payload, and non-holonomic constraints will be considered to. A finite element solution method based on mixed method is applied to model the shear deformation. This procedure is considerably more involved than displacement based element and shear deformation can be readily included without inducing the shear locking in the element. Another goal of this paper is to present a computational procedure for determination of the maximum dynamic load of geometrically nonlinear manipulators with structural and joint flexibility. An effective measure named as Moment-Height Stability (MHS) measure is applied to consider the dynamic stability of a wheeled mobile manipulator. Simulations are performed for mobile base manipulator with two flexible links and joints. The results represent that dynamic stability constraint is sensitive when calculating the maximum carrying load. Furthermore, by changing the trajectory of end effector, allowable load also changes. The effect of torsional spring parameter on the joint deformation is investigated in a parametric sensitivity study. The findings show that, by the increase of torsional stiffness, the behavior of system approaches to a system with rigid joints and allowable load of robot is also enhanced. A comparison is also made between the results obtained from small and large deformation models. Fluctuation range in obtained figures for angular displacement of links and end effector path is bigger for large deformation model. Experimental results are also provided to validate the theoretical model and these have good agreement with the simulated results.