• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.124-126
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• 2009

In this paper a pendulum-driven type spherical mobile robot is introduced. Many researchers have been studied about a spherical mobile robot. we developed a pendulum-driven type spherical mobile robot and analyzed mechanism of pendulum motion. Mechanism of pendulum motion applied to the robot. Consequently, we could verify the motion of the robot as motion of pendulum.

• The Journal of Korea Robotics Society
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• v.6 no.4
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• pp.323-333
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• 2011

Due to the limited pendulum motion range, the conventional one-pendulum driven spherical robot has limited driving capability. Especially it can not drive parallel direction with center horizontal axis to which pendulum is attached from stationary state. To overcome the limited driving capability of one-pendulum driven spherical robot, we introduce a spherical robot, called KisBot II, with a new type of curved two-pendulum driving mechanism. A cross-shape frame of the robot is located horizontally in the center of the robot. The main axis of the frame is connected to the outer shell, and each curved pendulum is connected to the end of the other axis of the frame respectively. The main axis and pendulums can rotate 360 degrees inside the sphere orthogonally without interfering with each other, also the two pendulums can rotate identically or independent of each other. Due to this driving mechanism, KisBot II has various motion generation abilities, including a fast steering, turning capability in place and during travelling, and four directions including forward, backward, left, and right from stationary status. Experiments for several motions verify the driving efficiency of the proposed spherical robot.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.7
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• pp.713-717
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• 2014

In this paper, the travel control of the spherical wheeled robot with a mecanum wheel is impelemented. Four typical wheels or three omni wheels are used to consist of the ball-bot. the slip is occured when the typical wheels is used to the ball-bot. In order to reduce these slip, the spherical wheeled robot with macanum wheels is proposed. Through some experiments, we find that the proposed spherical wheeled robot with a mecanum wheel is superior to the conventional spherical wheeled robot with typical wheels.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.11
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• pp.1060-1067
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• 2010

In this paper, we present a new type of spherical robot having two arms. This robot, called KisBot, mechanically consists of three parts, a wheel-shaped body and two rotating semi-spheres. In side of each semi-sphere, there exists an arm which is designed based on slider-crank mechanism for space efficiency. KisBot has hybrid types of driving mode: rolling and wheeling. In the rolling mode, the robot folds its arms through inside of itself and uses them as pendulum, then the robot works like a pendulum-driven robot. In the wheeling mode, two arms are extended from inside of the robot and are contacted to the ground, then the robot works like a one-wheel car. The Robot arms can be used as a brake during rolling mode and add friction to the robot for climbing a slope during wheeling mode. We developed a remote controlled type robot for experiment. It contains two DC motors which are located in the center of each semi-sphere for main propulsion, two RC motors for each arm operation, speed controllers for each semi-sphere, batteries for main power source, and other mechanical components. Experiments for the rolling and wheeling mode verify the hybrid driving ability and efficiency of the our proposed spherical robot.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1605-1608
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• 1997

In this paper, a new onmidirectional robot with one spherical wheel is porposed. The peculiar structure of the proposed mobile robot makes it possible not only to move sideways but to be easy to implement. The wheel is derived by two stepping motors and equipped with 8-infrared sensors. To prove the validity of the proposed robot, the experiment of going through a way is performed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.141-142
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• 2009

• Proceedings of the IEEK Conference
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• summer
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• pp.263-268
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• 2004

The inverse kinematics problem is to find a set of joint variable values that will place the end effector of a robot manipulator into a given pose. Pieper has shown that a sufficient condition for a manipulator to have a closed form solution is that three adjacent joint axes intersects, hence the six axes robot with spherical wrist allows closed form solution. But many industrial robots have a non-spherical wrist to provide a stronger wrist configuration so that they can handle heavy payloads. Also, the use of a non-spherical wrist can result in a cheap and simple wrist arrangement than when all three axes intersect at a common point. In these cases, closed form solutions cannot be found. Therefore numerical technique must be used to solve the inverse kinematics equations. This paper proposes a new algorithm that can be used for finding inverse kinematics solution of the six axes robot with non-spherical wrist. Computer simulations are provided to prove the usefulness of our method.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.3
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• pp.333-344
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• 2014

This is the survey paper on the role of kinematics in robot development. The robot is considered as a form of mechanical systems which includes closed-chain loop system, open-chain loop system and closed and open switching system. To analyze these systems, kinematic notations has been developed in kinematics of mechanical theory since 1955 and has been applied in robotics. Several kinematic notations including Denavit-Hartenberg notations have been reviewed. The status of development of the spherical motor which has a great impact on the future robot advancement has reviewed, and research activity on a spherical motor and its application to 3-D spatial mechanisms at UNIST is introduced. For the open and closed switching mechanical systems, the bipedal robots' walking theories using Zero Moment Point are reviewed. And current status regarding bipedal robots based on newly developed passive dynamic walking theory is reviewed with the research activity at UNIST on this subject.

• Journal of Aerospace System Engineering
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• v.14 no.2
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• pp.36-43
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• 2020

Many countries and international organizations have carried out rover missions to explore planetary surfaces. Accordingly, the demand for mechatronics education, which is closely related to building exploratory robots, is also steadily increasing. However, due to the complexity in understanding the background information needed for mechatronics, it is hard for pre-college students to study such process. In this study, we suggest an educational platform for mechatronics using a combined robot kit with a spherical robot and a smartphone application. To provide a visual understanding, the dynamic model of the robot is constructed while analyzing the error between actual driving and a simulation, and the educational algorithm of the game and a feedback method are proposed to improve the learning efficacy by considering the user's level of knowledge of mechatronics. We use this educational spherical robot to develop a curling game platform that can impart engineering education even when students lack significant knowledge.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.658-663
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• 2005

This paper presents the steering control algorithm of a locomotion robot using a quaternion. The locomotion robot is to be moved on an irregular floor that can inevitably result in the errors of both position and orientation. Especially the orientation error should be compensated every work in order to adjust the misaligned values of current orientation to those commanded values. In this paper, we propose a new steering control algorithm between the two values by using a quaternion with spherical cubic interpolation. The proposed algorithm is shown to be effective in terms of vibration when compared to a conventional simple compensation without interpolation, by using $MATLAB^{(R)}$ and $VisualNastran4D^{(R)}$.