• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.648-657
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• 2014

This paper is about the study on a newly developed small waterproofed 4-axis robot arm and the analysis of its kinematics and dynamics. The structure of robot arm is designed to have Pitch-Pitch-Pitch-Yaw joint motion for inspection using a camera on itself and the joint actuator driving capacity are selected and the joint actuators are designed and test for 10m waterproofness. The closed-form solution for the robot arm is derived through the forward and inverse kinematics analysis. Also, the dynamics model equation including the damping force due to the mechanical seal for waterproofness is derived using Newton-Euler method. Using derived dynamics equation, a sliding mode controller is designed to track the desired path of the developed robot arm, and its performance is verified through a simulation.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.3
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• pp.79-85
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• 2001

We obtain a solution of inverse kinematic of 3 axis manipulator by using a self-organizing neral network(SONN) with a fuzzy compensator. The self-organizing neural network using the gaussian potential function as the activation function has one hidden layer in the first learning time. The network obtains the optimal number of node by increasing the number of hidden layer node through the learning, and the fuzzy compensator has the optimal loaming rate of neutral network. In this results, we can confirmed that the learning rate is improved and the rapid convergence to the steady-state.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.108-116
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• 2005

Transplanting accuracy of a rice transplanter mainly depends on the trajectory of the hoe for picking, conveying and transplanting of seedlings as well as the return motion. The trajectory can be decided and prescribed to be suitable in treating seedlings fur a prevailing soil condition. For the purpose of the transplanting accuracy, the design of a transplanting mechanism would be carried out using a planetary-gear-train system instead of the four bar linkage system. In this study, a design method of transplanting mechanism is theoretically proposed by synthesizing a noncircular planetary-gear-train system fur the tool (hoe) to trace a prescribed trajectory. The method utilizes an optimization approach to decide the lengths of an arm and a tool, the inverse kinematics to figure out the configuration angles of the two links, the roll contact condition in transmitting motion between the gears, and a linearization approach to obtain the shapes of the gears. Based on the proposed method, the shapes of the gears and the lengths of the tools of the planetary-gear-train system are determined fur three prescribed trajectories. A kinematical simulation with a commercialized package program is also carried out to confirm that the gear-train system synthesized with the proposed method is able to trace the prescribed trajectory.

• Journal of Internet of Things and Convergence
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• v.4 no.2
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• pp.7-11
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• 2018

In this paper, kinematic based walking pattern generation of biped walking robot is reviewed. Biped walking robot should be consisted of 6 Degree of Freedom(DOF) for each leg to walk properly in 3 dimensional circumstance. In this paper, simple structure of biped robot is depicted for walking pattern firstly. After fixing path of ankle of the robot, angle joints are coming from kinematic equatioins. Coordination of joints of a robot was set for dynamic analysis also. So walking pattern of a robot will be designed using dynamic equations of coordination of joint angles. Finally, setting of ankle of robot and pattern generation are key procedures of the robot walking.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.4
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• pp.441-448
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• 2012

This paper describes the optimal home positioning algorithm of Eclipse-II, a new conceptual parallel mechanism for motion simulator. Eclipse-II is capable of translation and 360 degrees continuous rotation in all directions. In unexpected situations such as emergency stop, riders have to be resituated as soon as possible through a shortest translational and rotational path because the return paths are not unique in view of inverse kinematic solution. Eclipse-II is man riding. Therefore, the home positioning is directly related to the safety of riders. To ensure a least elapsed time, ZYX Euler angle inverse kinematics is applied to find an optimal home orientation. In addition, the subsequent decrease of maximum acceleration and jerk values is achieved by combining the optimal return path function with cubic spline, which consequently reduces delivery force and vibration to riders.

• The Journal of Korea Robotics Society
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• v.7 no.1
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• pp.35-44
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• 2012

This paper presents a method to optimize motion planning for industrial manipulators with redundancy. For optimal motion planning, first of all, particular inverse kinematic solution is needed to improve efficiency for manipulators with redundancy working in various environments. In this paper, we propose three kinds of methods for solving inverse kinematics problems; numerical and combined approach. Also, we introduce methods for optimal motion planning using potential function considering the order of priority. For efficient movement in industrial settings, this paper presents methods to plan motions by considering colliding obstacles, joint limits, and interference between whole arms. To confirm improved performance of robot applying the proposed algorithms, we use two kinds of robots with redundancy. One is a single arm robot with 7DOF and another is a dual arm robot with 15DOF which consists of left arm, right arm with each 7DOF, and a torso part with 1DOF. The proposed algorithms are verified through several numerical examples as well as by real implementation in robot controllers.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.1
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• pp.24-28
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• 2013

In this paper, a procedure of design and development of a child-sized humanoid robot is described. The design concept for a humanoid robot was proposed and the mechanism of the humanoid robot which is more than 1 meter tall was designed by using 3D design tools. By considering the lightweight of the robot, the hardware for the robot was designed for optimal performance. The frames and links of the robot designed by 3D design tools was manufactured through precision machining with the material which is light and have a good strength. The manufactured child-sized humanoid robot was experimented with basic motions applied inverse kinematics and balance control, and the performance of the motions were verified.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.2
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• pp.318-324
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• 2010

In this paper, the structure of the gravity compensator has been designed and applied to a light structure of a new 6-axis robot manipulator to enhance its torque performance. Also, analyses on the kinematics and inverse-kinematics of the manipulator have been performed. An FEM analysis has been performed on the structure of robot links to have an excellent performance of delivering 25 kg payload despite of 30kg weight, which is very light compared with other manipulators. Through the FEM analysis, the stability on the vending or fracture of the links of the robot manipulator has been verified.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.3
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• pp.253-261
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• 2015

A parallel mechanism with redundancy can be regarded as a means for not only maximizing the benefits of parallel mechanisms but also overcoming their drawbacks. We proposed a novel parallel mechanism by eliminating an unnecessary degree of freedom of the configuration space. Because of redundancy, however, the solution for the inverse kinematics of the developed parallel mechanism is infinite. Therefore, we defined a cost function that can minimize the movement time to the target orientation and found the solution for the inverse kinematics by using a numerical method. In addition, we proposed a method for determining the boundary of the geometric singularity in order to avoid singularities.

• Nuclear Engineering and Technology
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• v.27 no.5
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• pp.661-669
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• 1995

A mobile robot, named KAEROT, has been developed for inspection and maintenance operations in nuclear facilities. The main feature of locomotion system is the planetary wheel assembly with small wheels. This mechanism has been designed to be able to go over the stairs and obstacles with stability. This paper presents the inverse kinematic solution that is to be operated by remote control. The automatic stair climbing algorithm is also proposed. The. proposed algorithms generates the moving pathes of small wheels and calculates the angular velocity of 3 actuation wheels. The results of simulations and experiments are given for KAEROT peformed on the irregular stairs in laboratory. It is shown that the proposed algorithm provides the lower inclination angle of the robot body and increases its stability during navigation.