• 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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.929-934
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• 2004

As 3D scanner develops, it can be used in measurement. To accomplish complete 3D measurement, the scanner has to view different sides of the target. It can be done by moving the scanner and fix it at every measuring point. By human, it would take so much time. However, by using robot, measuring time can be reduced and the procedure can be automated. It is suitable for 6R serial manipulator to do this kind of work in which the scanner should go any position in arbitrary orientation. We did inverse kinematics analysis by analytical and graphical methods. Then, we compared two methods.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.6
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• pp.1421-1429
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• 1994

An algorithm is developed for solving the inverse kinematic problem of a 6-degree-of-freedom robot with a wrist offset for which the closed form inverse solutions are not obtainable, but knowledge of one joint variable allows closed form solutions of the remaining joint variables. The algorithm does not require Forward Kinematics nor Jacobian but uses the implicit kinematic relationships between joint variables and the given hand position. An iterative back substitution method is used to solve the inversion and the optimal conditions of the convergence are incoporated. An example is given to illustrate the concepts, the solution procedure and its convergency.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.2
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• pp.168-172
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• 2001

The accuracy problem of robot manipulators has long been one of the principal concerns in robot design and control. A practical and economical way of enhancing the manipulator accuracy, without affecting its hardware, is kinematic calibration. In this paper an effective and practical method is presented for kinematic calibration of Stewart platforms. In our method differential errors in kinematical parameters are linearly related to differential errors in the platform pose, expressed through the forward kinematics. The algorithm is tested using simulated measurement in which measurement noise is included.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.259-260
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• 2014

IT 기술의 발달로 인해 로봇공학은 전문가의 영역에서 비전문가의 영역까지 두루 사용되고 있다. 그러나 현재 존재하는 소프트웨어는 여전히 높은 진입 장벽을 가지고 있다. 비전문가가 실질적으로 참고자료가 많이 부족하기 때문에 로봇 제어가 쉽지 않다. 본 논문에서는 5 자유도를 가진 로봇 팔을 움직이게 할 때 사용하는 기존의 역기구학(Inverse Kinematics)을 활용하여 기존 방법의 난도보다 직관적인 방법을 제시하여 비전문가들에게 로봇에 대한 높은 접근성을 제시한다.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.230-233
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• 1993

This paper described a relationship between motion speed and working accuracy of industrial articulated robot arms. Working accuracy of the robot arm deteriorates at high speed operation caused by a nonlinear transformation of the kinematics and the time delay of the robot arm dynamic. The deterioration of the following trajectory was expressed as a linear function of the squares of the robot arm motion speed, depending upon a posture of the robot arm and division interval of the objective trajectory.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.6
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• pp.63-68
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• 2000

This paper describes the conceptual design of new robot hand by type synthesis. The conventional robot hands with rotational movement have bad controllability because the distance between the final rotational joint and the center of things grasped is changed according to the size of things grasped. This paper uses the systematic procedure of type synthesis and the knowledge for designing robot hands. The new 6-bar Watt I type conceptual robot hand with rectilinear translational movement is proposed.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.511-517
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• 1988

Movement order program of robot operating program is generally made by teach-in method. Therefore in most cases it is sufficient as long as the robot system shows a reguired repeatability for the working conditions. But the trend in the robot application moves to the automatic generation of the working programs. A mathematical robot model similar to the reality is necessary for the analysis of the kinematic transformation of the robot system. The purposes of this paper are to make a better describing form and to suggest an automatic algorithm for kinematic parameter identification.

• 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.

• The Journal of Korea Robotics Society
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• v.15 no.3
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• pp.212-220
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• 2020

This paper deals with a strategy of gain optimization for the kinematic control algorithm of a wire-driven surgical robot. The proposed controller consists of the closed-loop inverse kinematics with the back-calculation method. The closed-loop inverse kinematics has 18 PID control gains, and the back-calculation method has 6 gains. An efficient strategy is designed to optimize 18 values first and then the remaining 6 values. The optimal gain sets are searched under the step input with performance indices. In this gain optimization, the objective function is defined as the minimum value of signal-to-noise ratio of the performance indices for 6 DoF (Degree-of-Freedom) motion that is based on the Taguchi method, and the constraints are applied to obtain stable responses for each motion evenly. The gain sets obtained are verified by simulations using the test trajectories. In comparative results, the optimal gain value based on the performance index combined with ISE (integral of square error) and settling time showed the best control performance.