• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.539-544
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• 1991

In order to verify robot motions for a desired work, it is necessary to visualize it on a computer screen. This paper presents a simulation algorithm for robot manipulator motion. Kinematic description is based on the Denavit- Hartenberg link representation. In order to be applied to various types of the robot manipulator, inverse kinematics make use of the Newton-Raphson iterative method with the least squares method. Joint variables are interpolated by the lowest polynomial segment satisfying acceleration continuity. The robot motions are generated and then animated on a computer screen in the form of skeleton type.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.388-393
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• 1990

A robot manipulator and an obstacle are described mathematically in joint space, with the mathematical representation for the collision between the robot manipulator and the obstacle. Using these descriptions, the robot motion planning problem is formulated which can be used to avoide a time varying obstacle. To solve the problem, the constraints on motion planning are discretized in joint space. An analytical method is proposed for planning the motion in joint space from a given starting point to the goal point. It is found that solving the inverse kinematics problem is not necessary to get the control input to the joint motion controller for collision avoidance.

• The KIPS Transactions:PartB
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• v.10B no.6
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• pp.657-664
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• 2003

Reliable tracking of moving humans is essential to motion estimation, video surveillance and human-computer interface. This paper presents a new approach to human motion tracking that combines appearance-based and model-based techniques. Monocular color video is processed at both pixel level and object level. At the pixel level, a Gaussian mixture model is used to train and classily individual pixel colors. At the object level, a 3D human body model projected on a 2D image plane is used to fit the image data. Our method does not use inverse kinematics due to the singularity problem. While many others use stochastic sampling for model-based motion tracking, our method is purely dependent on nonlinear programming. We convert the human motion tracking problem into a nonlinear programming problem. A cost function for parameter optimization is used to estimate the degree of the overlapping between the foreground input image silhouette and a projected 3D model body silhouette. The overlapping is computed using computational geometry by converting a set of pixels from the image domain to a polygon in the real projection plane domain. Our method is used to recognize various human motions. Motion tracking results from video sequences are very encouraging.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.10
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• pp.1121-1232
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• 1990

A hierarchical neural network structure is described for robot PTP trajectory planning. In the first level, the multi-layered Perceptron neural network is used for the inverse kinematics with the back-propagation learning procedure. In the second level, a saccade generation model based joint trajectory planning model in proposed and analyzed with several features. Various simulations are performed to investigate the characteristics of the proposed neural networks.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.16-20
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• 1988

This paper presents a new algorithm for solving the inverse kinematics in real-time applications. The end-tip movement of each link can be resolved into the basic resolution unit, .DELTA.l, which depends on link length, reduction ratio and resolution of the incremental encoder attached to the joint. When x- and y-axis projection of the end-tip movement are expressed in .DELTA.l unit, projectional increments .DELTA.x and .DELTA.y become -1, 0 or I by truncation. By using the incremental computation with these ternary value and some simple logic rules, a coordinate transformation can be realized. Through this approach, it should be noted that the floating-point arithmetic and the manipulation of trigonometric functions are completely eliminated. This paper demonstrates the proposed method in a parallelogram linkage type, two-link arm.

• Journal of the Semiconductor & Display Technology
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• v.10 no.4
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• pp.79-87
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• 2011

In this paper, suggested is a hybrid-type visual alignment system to align mask and panel in 3-D space, where mask and panel are to be controlled independently by two individual positioning mechanisms in order to compensate for spatial misalignments. In the hybrid visual alignment system, the below 4-PPR parallel mechanism provides in-plain motions to pattern mask like the other conventional alignment systems while the above 4-RPS parallel mechanism is to move glass panel to achieve a complete spatial alignment. For the control of the hybrid alignment system, first, inverse kinematic solutions for the parallel mechanisms are given to determine the driving distance of each active joint, and also an efficient way to determine the spatial alignment error is developed by exploiting three in-plane cameras.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1013-1016
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• 1995

This paper deals with dynamics and control of a PRP6-DOF parallel manipulator. Dynamic modeling includes the effect of inertia of all links in the mechanism to increase modeling accuracy. Kinematic analysis about forward and inverse kinematics is also explained. Using Lagrange-D' Alambert method we get equations of motions in a link space which fully represent 6DOF motions of the manipulator.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.1-5
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• 1988

The realization of high quality robot control needs the improvement of computing speed of controller. In this paper, parallel processing method is considered for this purpose. A S/W algorithm for task scheduling is developed first, and then, an appropriate H/W structure is proposed. This scheme is applied to calculate inverse kinematics of PUMA robot. The simulation results show that the computing time when using three 8086/87's is reduced to 4.23 msec compared to 10 msec in case using one 8086/87.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.23-28
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• 1987

A Computer Aided Design (CAD) program of robot application engineering has been developed for the efficient examination of HR8000 robot. For the Simulation of robot motion. direct and inverse kinematics of robot manipulator was analyzed and robot motion was visualized. The program could contribute to upgrade accuracy and to minimize the time for the robot application engineering.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.5
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• pp.90-97
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• 2014

This paper presents a simplified dynamics model, dynamics simulations, and computed torque control experiments of the Delta high-speed parallel robot. Using the typical Newton-Euler method, a simplified but accurate dynamics model with practical assumptions is derived. Accuracy and fast calculations of the dynamics are essential in the computed torque control for high-speed applications. It was found that the simplified dynamics equation is in very god agreement with the ADAMS model, and the calculation time of the inverse kinematics and inverse dynamics is about 0.04 msec. From the dynamics simulations, the cycle trajectory along the y-axis requires less peak motor torque and a lower angular velocity and less power than that along the x-axis. The computed torque control scheme can reduce the position error by half as compared to a PD control scheme. Finally, the developed Delta parallel robot prototype, half the size of the ABB Flexpicker robot, can achieve a cycle time of 0.43 sec with a 1.0kg payload.