• Journal of Institute of Control, Robotics and Systems
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• v.5 no.1
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• pp.105-114
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• 1999

By using the conceptual impedance and the elasticity of a serial chain of spring-damper system, a real-time collision-free trajectory generation algorithm is proposed. The reference points on a trajectory connected by the spring-damper system have a mechanism for self-Position adjustment to avoid a collision by the impedance, and the local adjustment of each reference point is propagated through the elasticity to a real robot at the end of the spring-damper system. As a result, the overall trajectory consisting of the reference points becomes free of collision with environmental obstacles and efficient having the shortest distance as possible. In this process, the reference points connected by the spring-damper system take role of virtual robot as global guidance for a real robot, and a cooperative optimization is carried out by the system of virtual robots. A control algorithm is proposed to implement the impedance for a car-like mobile robot.

• Proceedings of the IEEK Conference
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• 2000.06e
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• pp.159-162
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• 2000

This paper addresses the design and implementation problem of the mobile robot with the synchronous driving mechanism that consists of modular control systems based on the Universal Serial Bus (USB). Recently, the USB have attracted the hardware developers'interests due to its low cost, compatibility, and extenability. In particular, the USB enables us to organize the whole system in the modular manner very easily, and this property plays a very important role in shortening the developing time in implementing the target system, for example, the mobile robot system. In this paper, we implement the USB motion controller and the USB ultrasonic sensor system and verified the validity and the effectiveness of the proposed system through the real experiments including the mobile robot navigation and the environment recognition.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.478-478
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• 2000

In this paper, presents the design of mobile field robot controlled by microcomputer. The computer works as the supervisory system for decision making and sending command to control the field robot. An information from encoder, infrared sensors using for control task of the robot that can be interconnected with the computer through the serial communication RS422 standard. In this case, the user can design the program algorithm base on microcomputer in order to control and define the routing of the mobile robot. Moreover, the robot can be installed other equipment fer collect data such as picture, sound, temperature etc., in order to working in the dangerous area.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.419-423
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• 2005

In microfactory, loading/unloading mechanism supply the row material to processing machines for manufacturing process such as pressing, cutting, plastic deformation. This mechanism for rnicrofactory is designed as modularity robot. Microfactory system have to be flexible structure for variety product item. For system flexibility, applied mechanisms are developed as moduality. Robot moduality needs the specific characteristics which are different from one of macro, typical robot system. In this paper, we discussed about the modularity robot. and proposed the loading/unloading mechanism for working in microfactory system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.395-402
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• 2016

This paper presents a design methodology for improving the energy efficiency by considering the inertial properties of serial manipulators. This method employed is to put the inertia matrix, which has a critical effect on the equation of motion, into the constraints of the optimization problem. Through the optimization process, we propose a design algorithm that can double-check whether the optimized parameters satisfy the required performance or not by using an auxiliary index associated with the inertia and energy. Using this design algorithm, we were able to improve the energy efficiency by minimizing the torque. We applied this method to a 3 degrees of freedom serial manipulator and simulated it.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.6
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• pp.492-497
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• 2016

Teaching an industrial robot is still a dangerous and time-consuming process. It is expected that a robot can track a trajectory that is repeatedly taught by a human operator. Teaching a robot in joint space is easier than that in Cartesian space or a work space because the robot will never lose its stability when it is taught and operated in a joint space. However, it is very easy for a robot to lose its stability when it is taught in a work space. This is because of the singular points problem in kinematics for manipulators. Thus, experts should teach a given task to a robot in a careful manner. A new algorithm that avoids the problem of singular points is proposed. Using this proposed method, a user can freely teach a robot without the chance of instability in an entire work space.

• Journal of Welding and Joining
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• v.16 no.3
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• pp.129-140
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• 1998

An interface system was developed to offer the welding capability to a robot controller which had not any embedded function for arc welding before, and also an arc sensor algorithm was proposed for weld seam tracking of the welding robot. For the interface system between the robot controller and welding equipments, data communication software and interface connections were composed. The interface system was mae to correspond welding condition, correction data, operation sequence and current status with the robot controller by mutual had shaking and digital signal transfer. Graphic user interface program developed under the environment of windows made it easy to monitor data communication and operation status, and to control welding and sensing sequence. Arc sensing algorithm proposed in this study to compensate torch position error was based on a fuzzy logic with the variables of current difference and current differenced change at torch weaving extremities. The developed interface system could be successfully implemented in between welding equipments and the robot controller, and showed normal status and exact function in data and signal communication between the systems. The whole robot welding system was then examined to verify its welding and seam tracking capabilities in horizontal fillet, vertical fillet, and 3-dimensional fillet weldment. The experiments revealed sound weld bead shapes and also good seam tracing results.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.1
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• pp.142-149
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• 1995

This paper presents a new kinematic control strategy for serial redundant manipulators which gives repeatability in the joint space when the end-effector undergoes some general cyclic motions. Theoretical development has been accomplished by deriving a new inverse kinematic equation that is based on springs being conceptually located in the joints of the manipulator. Although some inverse kinematic equations for serial redundant manipulators have been derived by many researchers, the new strategy is the first to include the free angles of torsional springs and the free lengths of the translational springs. This is important because it ensures repeatability in the joint space of a serial redundant manipulator whose end-effector undergoes a cyclic type motion. Numerical verification for repeatability is done in terms of Lie Bracket Condition. Choices for the free angle and torsional stiffness of a joint (or the free length and translational stiffness) are made based upon the mechanical limits of the joints.

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.1
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• pp.76-80
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• 2001

A binary parallel robot manipulator uses actuators that have only two stable states being built by stacking variable geometry trusses on top of each other in a long serial chain. Discrete characteristics of the binary manipulator make it impossible to analyze an inverse kinematic problem in conventional ways. We therefore introduce new definitions of workspace and inverse kinematic solution, and the apply a genetic algorithm to the newly defied inverse kinematic problem. Numerical examples show that our genetic algorithm is very efficient to solve the inverse kinematic problem of binary robot manipulators.

• Journal of Biomedical Engineering Research
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• v.24 no.2
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• pp.127-132
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• 2003

In this paper. the pneumatic service robot with a hybrid type is developed. A pneumatic has the advantages of good compliance , high Payload-to-weight and payload-to-volume ratios. high speed and force capabilities. Using pneumatic actuators. which have low stiffness. the service robot can guarantee safety. By suggesting a new serial-parallel hybrid type for the service robot which separates into Positioning motion and orienting motion, we can achieve large workspace and high strength-to-moving-weight ratio at the same time. A sliding mode controller can be designed for tracking the desired output using the Lyapunov stability theory and structural properties of pneumatic servo systems. Through many experiments of circular trajectory. the Pneumatic service robot is evaluated and verified.