• Title/Summary/Keyword: inverse approach

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Inverse Kinematics of Robot Fingers with Three Joints Using Neural Network (신경회로망을 이용한 3관절 로봇 손가락의 역기구학)

  • Kim, Byeong-Ho
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2007.11a
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    • pp.159-162
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    • 2007
  • The inverse kinematics problem in robotics is an essential work for grasping and manipulation tasks by robotic and humanoid hands. In this paper, an intelligent neural learning scheme for solving such inverse kinematics of humanoid fingers is presented. Specifically, a multi-layered neural network is utilized for effective inverse kinematics, where a dynamic neural learning algorithm is employed. Also, a bio-mimetic feature of general human fingers is incorporated to the learning scheme. The usefulness of the proposed approach is verified by simulations.

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Inverse Model Parameter Estimation Based on Sensitivity Analysis for Improvement of PM10 Forecasting (PM10 예보 향상을 위한 민감도 분석에 의한 역모델 파라메터 추정)

  • Yu, Suk Hyun;Koo, Youn Seo;Kwon, Hee Yong
    • Journal of Korea Multimedia Society
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    • v.18 no.7
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    • pp.886-894
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    • 2015
  • In this paper, we conduct sensitivity analysis of parameters used for inverse modeling in order to estimate the PM10 emissions from the 16 areas in East Asia accurately. Parameters used in sensitivity analysis are R, the observational error covariance matrix, and B, a priori (background) error covariance matrix. In previous studies, it was used with the predetermined parameter empirically. Such a method, however, has difficulties in estimating an accurate emissions. Therefore, an automatically determining method for the most suitable value of R and B with an error measurement criteria and posteriori emissions accuracy is required. We determined the parameters through a sensitivity analysis, and improved the accuracy of posteriori emissions estimation. Inverse modeling methods used in the emissions estimation are pseudo inverse, NNLS (Nonnegative Least Square), and BA(Bayesian Approach). Pseudo inverse has a small error, but has negative values of emissions. In order to resolve the problem, NNLS is used. It has a unrealistic emissions, too. The problems are resolved with BA(Bayesian Approach). We showed the effectiveness and the accuracy of three methods through case studies.

Inverse Approach to Study the Mechanical Properties of the Human Cornea and its Application to the Excimer Laser Surgery (역(逆)접근 방법에 의한 각막의 물성치 연구와 엑시머 레이저 수술에의 응용)

  • Huh, Jun-Young;Shin, Jung-Woog;Han, Geun-Jo
    • Proceedings of the KOSOMBE Conference
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    • v.1994 no.05
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    • pp.127-130
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    • 1994
  • This study is focused on investigating the mechanical properties of the human cornea and its shape through the inverse nonlinear finite element approach using the clinical and experimental data. The results of the inverse approach were used to construct the finite element model of the photorefractive excimer laser surgery for the myopia patients. The results of the finite element model were compared with those of the current clinical experiences and showed good agreements. Finally this study came to the conclusion that the finite element method has potential of the application to the medicine.

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Path Control for NeuroMate Robot in a Skull Drilling System (두개골 천공을 위한 NeuroMate 로봇의 경로 제어)

  • Chung, Yun-Chan
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.2
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    • pp.256-262
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    • 2013
  • This paper presents a linear path control algorithm for NeuroMate robot in a skull drilling system. For the path control inverse kinematics of the robot is analyzed and a linear interpolation algorithm is presented. A geometric approach is used for solving inverse kinematic equations for the robot. Four feasible solutions are found through the approach. The approach gives geometric insights for selecting the best solution from the feasible solutions. The presented linear interpolation algorithm computes a next position considering current velocity and remaining distance to the target position. Presented algorithm is implemented and tested in a skull drilling system.

Simplified Approach for Distortion Estimation in H.264 (H.264에서 간소화된 기법에 의한 왜곡치 예측)

  • Park, Ki-Hong;Kim, Yoon-Ho
    • Journal of Advanced Navigation Technology
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    • v.14 no.3
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    • pp.446-451
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    • 2010
  • This paper addressed an another scheme of distortion estimation method based on simplified inverse quantization in H.264/AVC. The distortion is calculated by the difference of coefficient between quantized transform coefficients and that of inverse. In general, these process included such transforms as discrete cosine transform(DCT), quantization, inverse quantization(IQ), and Inverse DCT(IDCT). In proposed approach, IQ as well as IDCT process are skipped because of replacing a couple of approximated formulas. Some simulation have been conducted and it showed that the PSNR was almost the same, and reduced the rate-distortion optimization(RDO) mode decision time of 8~15% in comparison with conventional method.

Design of Weld Line of a Tailor Welded Blank by Inverse Finite Element Analysis (유한요소 역해석을 이용한 Tailor Welded Blank의 용접선 설계)

  • Lee, Choong-Ho;Huh, Hoon;Han, Soo-Sik
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1997.10a
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    • pp.89-92
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    • 1997
  • Design of a weld line in a tailor welded blank is indispensable for good manufacturing of stamped parts as assigned, since the intial weld line is distorted severely with forming. The initial weld line has to be determined such that desired weld line in a formed part can be obtained. The initial weld line was predicted by inverse finite element analysis from the desired weld line in a formed part. The inverse approach is applied to the cylindrical and square cup drawing with tailor welded blanks. The applications demonstrates that the approach is useful for design of weld line of tailor welded blank.

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Parameter estimation of an extended inverse power Lomax distribution with Type I right censored data

  • Hassan, Amal S.;Nassr, Said G.
    • Communications for Statistical Applications and Methods
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    • v.28 no.2
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    • pp.99-118
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    • 2021
  • In this paper, we introduce an extended form of the inverse power Lomax model via Marshall-Olkin approach. We call it the Marshall-Olkin inverse power Lomax (MOIPL) distribution. The four- parameter MOIPL distribution is very flexible which contains some former and new models. Vital properties of the MOIPL distribution are affirmed. Maximum likelihood estimators and approximate confidence intervals are considered under Type I censored samples. Maximum likelihood estimates are evaluated according to simulation study. Bayesian estimators as well as Bayesian credible intervals under symmetric loss function are obtained via Markov chain Monte Carlo (MCMC) approach. Finally, the flexibility of the new model is analyzed by means of two real data sets. It is found that the MOIPL model provides closer fits than some other models based on the selected criteria.

An inverse approach based on uniform load surface for damage detection in structures

  • Mirzabeigy, Alborz;Madoliat, Reza
    • Smart Structures and Systems
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    • v.24 no.2
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    • pp.233-242
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    • 2019
  • In this paper, an inverse approach based on uniform load surface (ULS) is presented for structural damage localization and quantification. The ULS is excellent approximation for deformed configuration of a structure under distributed unit force applied on all degrees of freedom. The ULS make use of natural frequencies and mode shapes of structure and in mathematical point of view is a weighted average of mode shapes. An objective function presented to damage detection is discrepancy between the ULS of monitored structure and numerical model of structure. Solving this objective function to find minimum value yields damage's parameters detection. The teaching-learning based optimization algorithm has been employed to solve inverse problem. The efficiency of present damage detection method is demonstrated through three numerical examples. By comparison between proposed objective function and another objective function which make use of natural frequencies and mode shapes, it is revealed present objective function have faster convergence and is more sensitive to damage. The method has good robustness against measurement noise and could detect damage by using the first few mode shapes. The results indicate that the proposed method is reliable technique to damage detection in structures.

Inverse Kinematic and Dynamic Analyses of 6-DOF PUS Type parallel Manipulators

  • Kim, Jong-Phil;Jeha Ryu
    • Journal of Mechanical Science and Technology
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    • v.16 no.1
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    • pp.13-23
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    • 2002
  • This paper presents inverse kinematic and dynamic analyses of HexaSlide type six degree-of-freedom parallel manipulators. The HexaSlide type parallel manipulators (HSM) can be characterized as an architecture with constant link lengths that are attached to moving sliders on the ground and to a mobile platform. In the inverse kinematic analyses, the slider and link motion (position, velocity, and acceleration) is computed given the desired mobile platform motion. Based on the inverse kinematic analysis, in order to compute the required actuator forces given the desired platform motion, inverse dynamic equations of motion of a parallel manipulator is derived by the Newton-Euler approach. In this derivation, the joint friction as well as all link inertia are included. Relative importance of the link inertia and joint frictions on the computed torque is investigated by computer simulations. It is expected that the inverse kinematic and dynamic equations can be used in the computed torque control and model-based adaptive control strategies.

A study on kinematics and inverse kinematics of industrial FANUC robot (산업용 FANUC robot의 kinematics와 inverse kinematics에 대한 연구)

  • 박형준;한덕수;이쾌희
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.551-556
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    • 1991
  • This paper deal with the solution of kinematics and inverse kinematics of industrial FANUC robot by the bisection method with IBM PC 386. The inverse kinematics of FANUC robot cannot be solved by the algebraical method, because arm matrix T$_{6}$ is very complex and 6-joint angles are associated with the position and the approach of end-effector. Instead we found other 5-joint angle by an algebraical method after finding .theta.$_{4}$ value by a bisection method.d.

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