• Title, Summary, Keyword: kinematic formula

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ELASTOKINEMATIC ANALYSIS OF A SUSPENSION SYSTEM WITH LINEAR RECURSIVE FORMULA

  • KANG J. S.
    • International Journal of Automotive Technology
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    • v.6 no.4
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    • pp.375-381
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    • 2005
  • This paper presents linear algebraic equations in the form of recursive formula to compute elastokinematic characteristics of a suspension system. Conventional methods of elastokinematic analysis are based on nonlinear kinematic constrant equations and force equilibrium equations for constrained mechanical systems, which require complicated and time-consuming implicit computing methods to obtain the solution. The proposed linearized elastokinematic equations in the form of recursive formula are derived based on the assumption that the displacements of elastokinematic behavior of a constrained mechanical system under external forces are very small. The equations can be easily computerized in codes, and have the advantage of sharing the input data of existing general multi body dynamic analysis codes. The equations can be applied to any form of suspension once the type of kinematic joints and elastic components are identified. The validity of the method has been proved through the comparison of the results from established elastokinematic analysis software. Error estimation and analysis due to piecewise linear assumption are also discussed.

Direct kinematic method for exactly constructing influence lines of forces of statically indeterminate structures

  • Yang, Dixiong;Chen, Guohai;Du, Zongliang
    • Structural Engineering and Mechanics
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    • v.54 no.4
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    • pp.793-807
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    • 2015
  • Constructing the influence lines of forces of statically indeterminate structures is a traditional issue in structural engineering and mechanics. However, the existing kinematic method for establishing these force influence lines is an indirect or mixed approach by combining the force method with the theorem of reciprocal displacements, which is yet inconsistent with the kinematic method for statically determinate structure. This paper proposes the direct kinematic method in conjunction with the load-displacement differential relation for exactly constructing influence lines of reaction and internal forces of indeterminate structures. Firstly, through applying the principle of virtual displacement, the formula for influence lines of reaction and internal forces of indeterminate structure via direct kinematic method is derived based on the released structure. Then, a computational approach with a clear concept and unified procedure as well as wide applicability based on the load-displacement differential relation of beam is suggested to achieve conveniently the closed-form expression of force influence lines, and exactly draw them. Finally, three representative examples for constructing force influence lines of statically indeterminate beams and frame illustrate the superiority of the proposed method.

Dynamic analysis of a multibody system using recursive-formula (반복형태식을 이용한 多物體系의 動力學的 해석)

  • 신상훈;유완석
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.6
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    • pp.1265-1272
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    • 1988
  • Kinematic and dynamic equations of open-loop mechanical systems are derived using the velocity transformation. The velocities of a link are defined by the velocities of the previous link and relative velocities between the links. The velocities and angular velocities are expressed with joint velocities and 6*1 velocity transformation vector. Using the velocity relations, recursive formula are derived and compared to the previous results. The derived recursive formula are modified and applied to the dynamic simulation of a vehicle. The computational efficiency of the vehicle simulation with the derived recursive formula is much enhanced.

A Kinematic Analysis on the Connecting Rod Mechanism in Swash-plate-type Hydraulic Axial Piston Motor (사판식 유압 피스톤 모터 커넥팅 로드 기구의 운동해석)

  • 하정훈;김경호;함영복;김성동
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.621-625
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    • 1997
  • Recently, wash plate type hydraulic axial piston motors are being in extensively used in the world, because of simple design, lightweight, effective cost. But the structural problem of swash plate type hydraulic axial piston motor is the limited angle of swash plate and lateral force having a undesirable effect in piston. To solve these problems. a connecting rod mechanism. which is commonly used in hent axis type motors, is considered to be applied the swash plate cype motor. In this paper, kinematic analysis is done on the connecting rod mechanism. A series of formula are derived and numerical calculations are done for a set of motor parameters.

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A Kinematic Analysis on Piston Rod Mechanism in Swashplate Type Hydraulic Axial Piston Motor/Pump Using Constant Velocity Joint (등속조인트를 적용한 사판식 유압 모터/점프의 로드형 피스톤에 대한 운동해석)

  • Kim K.H.;Kim S.D.;Ham Y.B.;Lee J.C.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.2 no.1
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    • pp.1-8
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    • 2005
  • Recently, swash plate type hydraulic axial piston motors/pumps are being extensively used in the world, because of simple design, light weight and effective cost. Structural problem of the swash plate type motor/pump is that tilting angle of swash plate should be limited to relatively small value and lateral farce on pistons has an undesirable effect in reciprocating motion. To solve these problems, piston rod mechanism, which is commonly used in bent axis type motor/pump, is considered to be applied to the swash plate type motor/pump. In this paper, kinematic analysis was done on the piston rod mechanism. A series of formula were derived and numerical calculations were done for a set of motor parameters.

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Parameter Determination of Rainfall Runoff Model by Storage Function Model (저유함수법에 의한 강우-유출모형의 변수추정)

  • 남궁달
    • Water for future
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    • v.18 no.2
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    • pp.175-185
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    • 1985
  • This paper discusses the posibility of synthesizing flood hudrographs by the stroage function model. Eight small watersheds from Han, Gum, Nakdong, Youngsan river system were selected for this purpose. The optimum constants are computed from the chi square criterion by the SDFP methods Based on these constants, equations for the storage constant and Lag time are derived from the kinematic wave theory and storage function theory. These relations are examined by using optimum constants of the storage function model and assumptive constant of the kinematic wave model. Main results are sumarized as follows. 1. Constants of the storage function model are closely related to those of the kinematic wave model. The formula obtained theoretically is difficult to use practically because of the unclaified definition of factors. 2. In order to estimate constants of the storage function model for the practical purpose, new equations are also proposed for mountaneous area. 3. The verification of proposed equation is made for several recorded floods for mountaeous areas.

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Transport Velocity of Perilla Grain on Oscillating Sieve in Elliptical Motion

  • Pang, Yeoun Gyu;Kim, Sang Hun
    • Journal of Biosystems Engineering
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    • v.43 no.3
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    • pp.194-201
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    • 2018
  • Purpose: The objective of this study was to propose a formula for the theoretical grain mean transport velocities of an elliptically moving oscillator by modifying the grain mean transport velocity formula applied to linear motion and to compare the calculated values with the experimental values of grain mean transport velocity. Methods: The values of the throwing index ($K_v$) and the maximum horizontal velocities for various positions on the elliptical oscillator were obtained using kinematic analysis. To obtain the actual grain transport velocity, the mean transport velocities of perilla grains at six positions on the sieve surface were measured using a high-speed camera and compared with the theoretical values. The cam with an eccentric bearing on the oscillator was designed to be eccentric by 1.6 cm so that the lengths of the major axis of the elliptical motion were 3.2-3.6 cm. The material used in the experiments was perilla grain. Results: The experimental result was consistent with the theoretical value calculated using the proposed formula ($R^2$ is 0.80). It is considered that the angle difference between the maximum accelerations in the directions vertical and horizontal to the sieve has as much influence on the grain mean transport velocity as the value of Kv itself. Conclusions: It was possible to theoretically obtain the grain mean transport velocities through a screening device in elliptical motion by modifying the formula of the grain mean transport velocities used in linear motion.

On gait control of a quadruped walking robot (사각 보행 로보트의 걸음새 제어에 관한 연구)

  • 임미섭;임준홍
    • 제어로봇시스템학회:학술대회논문집
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    • pp.113-118
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    • 1988
  • The problem of controlling static gaits of a Quadruped Walking Robot is investigated. A theoretical approach to the gait study is proposed in which the static stability margins for periodic gaits are expressed in terms of the kinematic gait formula. The effects of the stride length to the static stability are analyzed, and the relations between the static stability and the initial body configurations are examined. Extensive computer simulations are performed to verify the analysis results.

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