• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.813-816
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• 1991

Direct-drive SCARA-type industrial robots are increasingly used in the assembly process of small mechanical parts as well as electronic components, which uses direct-drive (DD) motors instead of reduction gear-type conventional motors for the actuators of manipulator arms. There are many advantages in using DD motors for robots, such as no backlash, low friction, high mechanical stiffness capability for fast and precise arm control, and high repeatability of positioning. However, there exist a number of difficulties which must be overcome to ensure proper construction and operation; increasing effects of load veriation and nonlinear and coupling dynamics, severe vibration caused by resonance of the manipulator components and low mechanical damping, etc. In order to handle these difficulties, lots of efforts have been made such as reduction of the arm inertia and elimination of the resonance, Performance evaluation of a recently developed, domestic DD robot shows that it works excellently compared with conventional robots. It, however, requires proved reliability and price competitiveness against its foreign counterparts.

• Journal of KSNVE
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• v.7 no.3
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• pp.387-392
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• 1997

This paper concerns a SCARA robot with the flexible forearm linked to the rigid upper arm. The equations of motion are derived by the Lagrangian mechanics. For controller design, the perturbation approach is taken to separate the original equations of motion into linear equations describing small perturbed motions and nonlinear equations describing purely rigid motion of the robot. To effect the desired payload motion, open loop control inputs are determined based on the inverse dynamics of the latter. In order to reduce the positional error during maneuver, an active vibration suppression is done. To this end, a feedback control is designed for robustness against disturbance on the basis of the linear equations and the LQR theory modified to have a prescribed degree of stability. The proposed control scheme shows satisfactory performances in experiments as well as in numerical simulations.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.8
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• pp.851-858
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• 2009

In this study, we propose a new input device using vision technology for positioning of multiple DOFs. The input device is composed of multiple Tags on a transparent table and a vision camera below the table. Vision camera detects LEDs at the bottom of each Tag to derive information of the ID, position and orientation. The information are used to determine position and orientation of remote target DOFs. Our developed approach is very reliable and effective, especially when the corresponding DOFs are from many independent individuals. We show an application example with a SCARA robot to prove the flexibility and extendability.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.472-477
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• 1996

This paper presents a new approachtothe design of adaptive control system using DSPs(TMS320C30) for robotic manipulators to achieve trajectory tracking by the joint angles. Digital signal processors are used in implementing real time adaptive control algorithms to provide an enhanced motion control for robotic manipulators. In the proposed control scheme, adaptation laws are derived from the improved Lyapunov second stability analysis method based on the adaptive model reference control theory. The adaptive controller consists of an adaaptive feedforward controller, feedback controller, and PID type time-varying auxillary control elements. The prpposed adaptive control scheme is simple in structure, fast in computation, and suitable for implementation of real-time control. Moreover, this scheme does not require an accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the adaptive controller is illustrated by simulation and experimental results for a SCARA robot.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.11
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• pp.796-803
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• 1988

In this paper, the design method, design techniques and structure of a language for a SCARA type industrial robot, are presented. The proposed new language is modular and expandable using the C programming language and the 8086 assembly language. It is composed of monitor mode which controls the main flow of the programs, editing mode which generates, corrects and edits the programs, execution mode which executes the generated programs, I/O mode which interacts with the external devices, and teach mode. The developed language is implemented on the robot controller to verify its performance.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.255-260
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• 2001

This paper presents a new approach to the design of neural control system using digital signal processors in order to improve the precision and robustness. Robotic manipulators have become increasingly important in the field of flexible automation. High speed and high-precision trajectory tracking are indispensable capabilities for their versatile application. The need to meet demanding control requirement in increasingly complex dynamical control systems under significant uncertainties, leads toward design of intelligent manipulation robots. The TMS320C31 is used in implementing real time neural control to provide an enhanced motion control for robotic manipulators. In this control scheme, the networks introduced are neural nets with dynamic neurons, whose dynamics are distributed over all the network nodes. The nets are trained by the distributed dynamic back propagation algorithm. The proposed neural network control scheme is simple in structure, fast in computation, and suitable for implementation of real-time control. Performance of the neural controller is illustrated by simulation and experimental results for a SCARA robot.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.241-245
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• 1995

This paper shows that the proposed fuzzy-sliding mode for SCARA robot control could reduce chattering problemed in sliding mode control and is robust against parameter uncertainties. It was very small quantities of chattering in the fuzzy-sliding mode control conpared with that in sliding mode control with two dead-band. In here, the sliding mode control with two dead-band is the method to reduce some chattering by changing into a continuous variable lower control input gain when a state value in pahase palne converged sithin two dead-band. But, the fuzzy-sliding mode control for more reducing chattering is the method to change control input by slicing mode into that by fuzzy rule within two dead-band. Simulations show that the effect of reducing chattering by the fuzzy-sliding mode is superior to sliding mode control with two dead-band.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.03a
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• pp.79-84
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• 1996

This paper presents a new approach to the design of adaptive control system using DSPs(TMS320C31) for robotic manipulators to achieve trajectory tracking by the joint angles. Digital signal processors are used in implementing real time adaptive control algorithms to provide an enhanced motion control for robotic manipulators. In the proposed control scheme, adaptation laws are derived from the improved Lyapunov second stability analysis method based on the adaptive model reference control theory. The adaptive controller consists of an adaptive feedforward controller, feedback controller, and PID type time-varying auxillary control elements. The proposed adaptive control scheme is simple in structure, fast in computation, and suitable for implementation of real-time control. Moreover, this scheme does not require an accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the adaptive controller is illustrated by simulation and experimental results for a SCARA robot.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.03a
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• pp.114-118
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• 1996

This paper proposes a new technique to the design of adaptive control system using DSPs(TMS320C50) for Digital signal processors are used in implementing real time adaptive control algorithms to provide motion for robotic manipulators. In the proposed scheme, adaptation laws are derived from the improved second stability analysis based on the indirect adaptive control theory. The proposed control scheme is simple in structure, fast in computation. an suitable for implementation of real-time control. Moreover, this scheme does not requre an accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the adaptive controller is illustrated by exeperimental reults for a SCARA robot.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.113.1-113
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• 2001

The robust position control with the bound function of neural network structure is proposed for uncertain robot manipulators. The neural network structure presents the bound function and does not need the concave property of the bound function, The robust approach is to solve this problem as uncertainties are included in a model and the controller can achieve the desired properties in spite of the imperfect modeling. Simulation is performed to validate this law for four-axis SCARA type robot manipulators.