• Journal of the Korean Society for Precision Engineering
• /
• v.12 no.10
• /
• pp.25-31
• /
• 1995

In this paper, a direct drive scalar robot manipulator is constructed and its mechanical machanism for operation is explained. Also, a motion controller board for the direct drive robot manipulator was developed where the IBM 486 computer is the main controller. For the developed direct drive robot, a force/motion control algorithm based on an active compliance scheme is developed. A preliminary experiment using the developed direct drive for a peg-in-hole job was done by implementing the control algorithm.

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.4
• /
• pp.140-147
• /
• 2008

This paper represents an ultra precision rotational device where the smooth impact drive mechanism (SIDM) is utilized as driving mechanism. Linear motions of piezoelectric elements are converted to the rotational motion of disk by frictional forces generated between the rotational disk and the friction part that is attached to the piezoelectric element. This device was designed to drive the rotational disk using slip-slip motion mechanism instead of stick-slip motion mechanism occurred in conventional impact drive mechanism. Experimental results show that the angular velocity is increased in proportion to the magnitude and frequency of supplied voltage to piezoelectric element and decreased as the preload is increased. In our device, the smooth rotational motion was obtained when the driving frequency has been reached to 500Hz under the driving voltage of 100V.

• Journal of Electrical Engineering and Technology
• /
• v.11 no.5
• /
• pp.1299-1304
• /
• 2016

• Journal of Institute of Control, Robotics and Systems
• /
• v.10 no.4
• /
• pp.357-363
• /
• 2004

Earlier models of card vending machines have generally motion drives with high cost and large size. However, current trend in card vending machines requires low-cost, compact-sized and readily installable motion drives. This paper shows the operational principle of the motion drive of a card vending machine and then presents the performance test results of the motion drive with improved mechanisms proposed in the paper. The results show that the proposed mechanism is valid and improves the card dispensing performance. The proposed model in the paper is accepted and introduced in the actual production line.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.485-486
• /
• 2006

This paper represents a ultra precision rotational device where the smooth impact drive mechanism(SIDM) is utilized as a driving mechanism. Linear motions of piezoelectric elements are converted to the rotational motion of disk by frictional forces generated between the rotational disk and the friction bars which are attached to the piezoelectric elements. This device was designed to drive a rotational disk using slip-slip motion mechanism based on stick-slip motion mechanism. Experimental results show that the angular velocity was increased in proportion to the magnitude of supplied voltage to piezoelectric element. In our device, the smooth rotational motion was obtained when the driving frequency has been reached to 500Hz under the driving voltage of 100V. The amount of step movement has been revealed to be $3.44{\times}10^{-4}$ radian.

• Journal of Advanced Marine Engineering and Technology
• /
• v.36 no.7
• /
• pp.894-901
• /
• 2012

For more efficient use of the high pressure water-jet in rehabilitation of the water pipes, we have studied the water-jet cleaning motion of the in-pipe robot with screw drive. The mathematical models of the water-jet in the straight and the curved pipe (90 degrees elbow), representative features of the water mains, were designed to understand the water-jet motion and simulations have been performed. Furthermore the experiments has been conducted to validate the simulations by using the prototype in-pipe robot in the 3-D pipeline. The simulation results show that the water-jet motion in the straight pipe has a constant water-jet interval, whereas the motion in the curved pipe is changed by its position. By the comparison of the simulation and the experimental results, we have demonstrated that the simulations successfully estimate the water-jet motion inside the water pipes. Therefore in-pipe robot operators can predict a water-jet motion for a target water pipe through the simulation and flexibly make a proper water-jet motion by changing the robot configurations before a cleaning work.

• Journal of Power System Engineering
• /
• v.17 no.3
• /
• pp.82-88
• /
• 2013

For commercialized servo drives of the motion stage to include embedded controller, external terminal is provided for tracking command and encoder output, but internal terminal is not for control input. Thus, it is difficult to combine out signal of embedded controller with that of external compensator such as disturbance observer. In this study, for precise tracking control of motion stage without hardware change of the servo drive, tacking control system is composed of an inner loop of servo drive and an outer loop of disturbance observer. Then, the control system is designed so that the output response of actual plant corresponds with nominal model's in transient state as well as in steady state. Finally, the experiment results show that the designed control system is effective to reconcile actual plant behavior with nominal model under nonlinear friction and parameter perturbation.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.6 no.3
• /
• pp.112-118
• /
• 2007

Recently, the machine tools called multi-task machines, which mounted rotary axes on the table or spindle are used increasingly. Accordingly, multi-task machine tool takes a growing interest on the motion accuracy of feed drive system. In this study, measurement and diagnosis of motion errors ware attempted from circular pattern obtained by using DBB (Double ball bar) device. Those were obtained at both clockwise and counter clockwise motions in mutually perpendicularly intersecting three planes. The reliability of error measurement system for multi-task machine tool was verified by the direct test cutting.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.6 no.3
• /
• pp.31-37
• /
• 2007

Recently, the machine tools called multi-task machines, which mounted rotary axes on the table or spindle are used increasingly. Accordingly, multi-task machine tool takes a growing interest on the motion accuracy of feed drive system. In this study, measurement and diagnosis of motion errors ware attempted from circular pattern obtained by using DBB (Double ball bar) device. Those were obtained at both clockwise and counter clockwise motions in mutually perpendicularly intersecting three planes. The reliability of error measurement system for multi-task machine tool was verified by the direct test cutting.

• Journal of Institute of Control, Robotics and Systems
• /
• v.12 no.2
• /
• pp.101-105
• /
• 2006

Disk radial runout creates a periodic relative motion between the laser beam spot and tracks formed on an optical disk. While only focus control is activated, the periodic relative motion yields sinusoid-like waves in the tracking error signal, where one cycle of the sinusoid-like waves corresponds to one track. The frequency of the sinusoid-like waves varies depending on the disk rotational speed and the amount of the disk radial runout. If the frequency of the tracking error signal in the off-track state is too high due to large radial runout of the disk, it is not a simple matter to begin track-following control stably. It might take a long time to reach a steady state or tracking control might fail to reach a stable steady state in the worst case. This article proposes a simple method for reducing the relative motion caused by the disk radial runout in the off-track state. The relative motion in the off-track state is effectively reduced by a drive input obtained through measurements of the tracking error signal and simple calculations based on the measurements, which helps reduce the transient response time of the track-following control. The validity of the proposed method is verified through an experiment using an optical disk drive.