• Title/Summary/Keyword: stewart platform

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Development of Driving Simulator Based on Washout Algorithm with Fuzzy Logic (퍼지에 기초한 워시아웃 알고리듬을 적용한 주행 시뮬레이터의 개발)

  • Jung, Ui-Jung;Song, Jae-Bok;Ko, Hee-Dong
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.654-659
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    • 2001
  • In the virtual environment, reality can be enhanced by offering the motion based on a motion simulator in harmony with visual and auditory modalities. In this research, the Stewart platform based motion simulator has been developed. This motion simulator is driven by the electric motors, and offers the slightly wider workspace compared to the commercial available simulators. In order to compensate for the limited range of the motion platform, the washout filters with fixed coefficients have been usually adopted. In this paper the new approach is proposed to tune the filter coefficients based on the fuzzy logic on the real-time basis. It is shown that performance with the variable filter coefficients is better than that with the fixed ones. The driving simulator based on the bicycle dynamics was developed by integrating the motion simulator and graphic system.

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A Driving Simulator of Construction Vehicles

  • Kwon Son;Goo, Sang-Hwa;Park, Kyung-Hyun;Yool, Wan-Suk;Lee, Min-Cheol;Lee, Jang-Myung
    • International Journal of Precision Engineering and Manufacturing
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    • v.2 no.4
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    • pp.12-22
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    • 2001
  • Vehicle driving simulators hale been used in the development and modification of models. A simulator can reduce cost and time through a variety of driving simulations in the laboratory. Recently, driving simulators have begun to proliferate in the automotive industry and the associated research community. This paper presents the hardware and software developed fur a driving simulator of construction vehicles. This effect involves the real-time dynamic analysis of wheel-type excavator, the design and manufacturing of the Stewart platform, an integrated control system of the platform, and three-dimensional graphic modeling of the driving environments.

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A Driving Simulator of Construction Vehicles (건설 중장비용 주행 시뮬레이터의 구현)

  • Son, Kwon;Goo, Sang-Hwa;Yoo, Wan-Suk;Lee, Min-Cheol;Lee, Jang-Myung
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.6
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    • pp.66-76
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    • 1999
  • Vehicle driving simulators have been used in the development and modification of models. A simulator can reduce cost and time through a variety of driving simulations in the laboratory. Recently, driving simulators have begun to proliferate in the automotive industry and the associated research community. This paper presents the hardware and software developed for a driving simulator of construction vehicles. This effor involves the real-time dynamic analysis of wheel-type excavator, the design and manufacturing of the Stewart platform, an integrated control system of the platform, and three-dimensional graphic modeling of the driving environments.

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Manipulability Analysis of a New Parallel Rolling Mill Based upon Two Stewart Platforms (두 개의 스튜어트 플랫폼을 이용한 병렬형 신 압연기의 조작성 해석)

  • 이준호;홍금식
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.11
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    • pp.925-936
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    • 2003
  • The manipulability analysis of the parallel-type rolling mill proposed in Hong et al. [1] is re-visited. The parallel rolling mill uses two Stewart platforms in opposite direction for the generation of 6 degree-of-freedom motions of each roll. The objective of this new parallel rolling mill is to permit an integrated control of the strip thickness, strip shape, pair crossing angle, uniform wear of rolls, and tension of the strip. New forward/inverse kinematics problems, in contrast with [1], are formulated. The forward kinematics problem is defined as the problem of finding the roll-gap and the pair-crossing angle of two work rolls for given lengths of twelve legs. On the other hand, the inverse kinematics problem is defined as the problem of finding the lengths of twelve legs when the roll-gap, the pair-crossing angle, and the position and orientation of one work roll are given. The method of manipulability analysis used in this paper follows the spirit of [1]. But, because the rolling force and moment exerted from both upper and lower rolls have been included in the manipulability analysis, more accurate results than the use of a single platform can be achieved. Two. kinematic parameters, the radius of the base and the angle between two neighboring joints, are optimally designed by maximizing the global manipulability measure in the entire workspace.

A development of the automated system for adjusting the 6 D.O.F circular fixator

  • Jung, Sang-Gil;Park, Bum-Seok;Sim, Hyung-Joon;Jang, Jae-Ho;Han, Chang-Soo;Han, Jung-Soo
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1642-1647
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    • 2004
  • In this article, we present the development of the automated system for adjusting the 6 D.O.F circular fixator. The system includes scheduling software to adjust the Hexapod Circular Fixator (HCF) and an automated strut system with the ability of the multiple synchronized motion. HCF was designed to control a 6 degree-of-freedom Ilizarove fixator and it's mechanism is known as the Stewart Platform. HCF scheduler evaluates each value of altered length of the HCF struts to correct the complex skeletal deformity by using the X-ray data of the patient. The data of HCF scheduler feed into the automated strut system which be able to provide the scheduled adjustment and the automated strut is synchronized by input data.

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New Closed-Form Direct Kinematic Solution of the 3-6 Stewart-Gough Platform Using the Tetrahedron Approach

  • Song, Se-Kyong;Kwon, Dong-Soo
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.83.4-83
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    • 2001
  • The paper presents a new closed-form, not a polynomial-form, solution of the direct kinematics of the 3-6 (Stewart-Gough) Platform. Many research works have presented a single high-order polynomial equation of the direct kinematics. However the polynomial equation causes potential problems such as complicated formulation procedures and discrimination of the actual solution from all roots, which results in time-consuming task and heavy computational burden. Thus, to overcome these problems, we use a new formulation approach, based on the Tetrahedron Approach, to derive easily a closed-form nonlinear equation of the direct kinematics and use not the Newton-Raphson method, but the Secant method to obtain quickly the solution from ...

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Design of a Cylindrical Flexure Jointed Stewart Platform for Aligning the Condenser in an X-ray Microscope

  • Kang Sung-Hoon;Kang Dong-Woo;Gweon Dae-Gab;Yoon Gwon-Ha;Min Jin-Young
    • International Journal of Precision Engineering and Manufacturing
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    • v.7 no.3
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    • pp.60-65
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    • 2006
  • This paper proposes a new type of six degree-of-freedom fine positioner that can be used to align the condenser in X-ray microscopy precisely. The new concept was based on the requirements for an X-ray microscope. A proposed modeling method was used to obtain an optimal design, which was verified with a finite element analysis. The fine positioner was then constructed and an experiment was used to validate its performance.

Analysis on Kinematic Characteristics of a Machine Tool Parallel Manipulator Using Neural Network (신경망을 이용한 공작기계 병렬 매니퓰레이터의 기구학 특성 분석)

  • Lee, Je-Sub;Ko, Jun-Bin
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.3
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    • pp.1-7
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    • 2008
  • This paper describes the kinematics which is a new type of parallel manipulator, and the neural network is applied to solving the forward kinematics problem. The parallel manipulator called it as a Stewart platform has an easy and unique solution about the inverse kinematics. However, the forward kinematics is difficult to get a solution because of the lack of an efficient algorithm caused by its highly nonlinearity. This paper proposes the neural network scheme of an Newton-Raphson method alternatively. It is found that the neural network can be improved its accuracy by adjusting the offset of the obtained result.

Development of Stewart Platform installed Turntable for Manned Flight Virtual Training Simulator (턴테이블을 적용한 유인비행체 가상훈련 시뮬레이터용 스튜어트 플랫폼 개발)

  • SO, Sangwon;Woo, Jaehoon;Hong, Chunhan
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.28 no.4
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    • pp.125-131
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    • 2020
  • In order to study the correlation between the pilot's cognitive ability and recovery ability by applying a physical element that can cause spatial loss of position to the pilot, a turntable was installed on the top of the motion system to give a quantitative rotational error. We propose a method of simulating flight movement to reduce a difference in feeling and an intuitive method of forward kinematic analysis.

The Study of Gain Optimization of Sliding Model Controller with Sliding Perturbation Observer by using of Genetic Algorithm

  • K.S. You;Park, M.K.;Lee, M.C.
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.495-495
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    • 2000
  • The Stewart platform manipulator is a closed-kinematis chain robot manipulator that is capable of providing high st겨ctural rigidity and positional accuracy. However, this is a complex structure, so controllability of the system is not so good. In this paper, it introduces a new robust motion control algorithm using partial state feedback for a class of nonlinear systems in the presence of modelling uncertainties and external disturbances. The major contribution of this work introduces the development and design of robust observer for the slate and the perturbation w.hich is integrated into a variable structure controller(VSC) structure. The combination of controller/observer gives rise to the robust routine called sliding mode control with sliding perturbation observer(SMCSPO). The optimal gains of SMCSPO are easily obtained by genetic algorithm. Simulation and experiment are presented in order to apply to the stewart platform manipulator. There results show highly' accuracy and performance.

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