• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.6
• /
• pp.535-541
• /
• 2014

In this research, three degree-of-freedom parallel spherical robot is developed for an artificial eyeball. The proposed system is comprised of a moving and a base plate, three prismatic actuators, and a ball joint for an angular movement of the moving plate. The vector analysis is employed to investigate the relationship between positions of the actuators and a pose of the moving plate. The required ranges for every actuators are calculated using the derived inverse kinematics in regard to the combination of two different levels for the size of the system component. Then the size of every components is determined from the analyzed trend. PI controller is employed for the position control of the moving plate. Finally the proposed system is verified using an arbitrary path of the angular movement.

• Journal of the Korean Society for Precision Engineering
• /
• v.26 no.10
• /
• pp.47-55
• /
• 2009

In this study, a robot foot having toes for firm stepping on uneven surface is proposed. The toes are connected to the lower leg by parallel links so that the lower leg can rotate in the rolling and pitching directions during stance phase without ankle joint. The landing performance of the foot on uneven surface was evaluated by relative comparison with that of the most common foot making point contact with the walking surface, since the test conditions considering real uneven surface could be hardly defined for its objective evaluation. Anti-slip margin(ASM) was defined in this study to express the slip resistance of a robot foot when it lands on a projection with half circular-, triangular- or rectangular cross section, assuming that uneven surface consists of projections having these kind of cross sections in different sizes. Based on the ASM analysis, the slip conditions for the two feet were experimentally confirmed. The results showed that the slip resistance of the new foot is not only higher than that of the conventional point contact type foot but also less sensitive to the surface friction coefficient.

• Journal of Institute of Control, Robotics and Systems
• /
• v.21 no.11
• /
• pp.1070-1075
• /
• 2015

This paper proposes a calibration algorithm for a three-degree-of-freedom (DOF) planar cable-driven parallel robot (CDPR). To evaluate the proposed algorithm, we calibrated winches and an optical tracking sensor, measured the end-effector pose using the optical tracking sensor, and calculated the accurate robot configuration using the measurement information. To conduct an accuracy test on the end-effector pose, we followed guidelines from "Manipulating industrial robots - Performance criteria and related test methods." Through the test, it is verified that the position accuracy can be improved by up to 20% for a $2m{\times}2m$-sized planar cable robot using the proposed calibration algorithm.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.05a
• /
• pp.53-54
• /
• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.05a
• /
• pp.283-284
• /
• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.10a
• /
• pp.175-176
• /
• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.1165-1166
• /
• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2011.06a
• /
• pp.351-352
• /
• 2011

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2011.06a
• /
• pp.329-330
• /
• 2011

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.11a
• /
• pp.125-126
• /
• 2010