• International Journal of Control, Automation, and Systems
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• 제3권2호
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• pp.173-182
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• 2005

In this paper, a target tracking algorithm for tracking maneuvering vehicles is presented. The overall algorithm belongs to the category of an interacting multiple-model (IMM) algorithm used to detect multiple targets using fused information from multiple sensors. First, two kinematic models are derived: a constant velocity model for linear motions, and a constant-speed turn model for curvilinear motions. Fpr the constant-speed turn model, a nonlinear information filter is used in place of the extended Kalman filter. Being equivalent to the Kalman filter (KF) algebraically, the information filter is extended to N-sensor distributed dynamic systems. The model-matched filter used in multi-sensor environments takes the form of a federated nonlinear information filter. In multi-sensor environments, the information-based filter is easier to decentralize, initialize, and fuse than a KF-based filter. In this paper, the structural features and information sharing principle of the federated information filter are discussed. The performance of the suggested algorithm using a Monte Carlo simulation under the two patterns is evaluated.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1669-1674
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• 2004

In this paper, a nonlinear information filter (IF) for curvilinear motions in an interacting multiple model (IMM) algorithm to track a maneuvering vehicle on a road is investigated. Driving patterns of vehicles on a road are modeled as stochastic hybrid systems. In order to track the maneuvering vehicles, two kinematic models are derived: A constant velocity model for linear motions and a constant-speed turn model for curvilinear motions. For the constant-speed turn model, a nonlinear IF is used in place of the extended Kalman filter in nonlinear systems. The suggested algorithm reduces the root mean squares error for linear motions and rapidly detects possible turning motions.

• Journal of Mechanical Science and Technology
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• 제18권4호
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• pp.550-559
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• 2004

In this paper, a recursive formulation for generating the equations of motion of spatial mechanical systems is presented. The rigid bodies are replaced by a dynamically equivalent constrained system of particles which avoids introducing any rotational coordinates. For the open-chain system, the equations of motion are generated recursively along the serial chains using the concepts of linear and angular momenta Closed-chain systems are transformed to open-chain systems by cutting suitable kinematic joints and introducing cut-joint constraints. The formulation is used to carry out the dynamic analysis of multi-link five-point suspension. The results of the simulation demonstrate the generality and simplicity of the proposed dynamic formulation.

• 제어로봇시스템학회논문지
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• 제5권2호
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• pp.208-219
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• 1999

Springs have been employed in a wide range of mechanical systems. This work deals with the concept of an adaptable spring mechanism which can arbitrarily modulate its spring characteristics. The adaptable spring is desired for enhancing performances of various mechanical systems employing springs. We demonstrate that such adaptable springs can be realized by adapting anthropomorphic musculoskeletal structures of the human upper-extremity, which possesses highly nonlinear kinematic-coupling among redundant muscles existing in its structures. This phenomenon has been explained by several human arm models. Based on the analysis results, we propose multi-degree-of-freedom spring mechanisms resembling the musculoskeletal structure of the human upper-extremity, and verifiy the applicability of these mechanisms through simulation.

• 대한기계학회논문집
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• 제18권9호
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• pp.2339-2348
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• 1994

The objective of this paper is to develop a solution method for the differential-algebraic equation(DAE) derived from constrained muti-body dynamic systems. Mechanical systems are often modeled as bodies and joints. Differential equations of motion are formulated for bodies. Since the bodies are connected by joint, the differential variables must satisfy the kinematic constraint equations that come from the joints. Difficulties are arised due to drift of the differential variables off the constraint equations. An optimization method is adopted to correct the drift of the differential variables. To demonstrate the efficiency of the proposed method a slider-crank mechanism is analyzed dynamically. Identical results are obtained as these from the commercial program DADS. Dynamic analysis of a High Mobility Multi-purpose Wheeled. Vehicle(HMMWV) is carried out to show the practicalism of the proposed method.

• 한국항행학회논문지
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• 제19권6호
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• pp.507-514
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• 2015

LX 한국국토정보공사 공간정보연구원에서는 2011년부터 LX 위성측위 (GNSS; global navigation satellite system) 네트워크를 구축하고 2014년부터 MAC (master-auxiliary correction) 방식의 네트워크 실시간 이동측위 (RTK; real-time kinematic) 전국망 운영 실험을 하고 있다. 본 연구에서는 LX GNSS 인프라의 구축 현황을 소개하고 LX GNSS RTK 서비스를 이용한 측위 성능 분석을 결과를 제시한다. 측위 성능 분석은 전북 전주, 서울, 그리고 인천에 설치된 지적도근점 중 총 25개를 이용하였으며, 1회 관측, 2회 중복관측, 그리고 5회 중복관측을 수행하였다. 측위 성능 비교를 위하여 한국국토정보공사 MAC과 국토지리정보원 VRS로 측량한 성과를 지적도근점의 고시좌표와 각각 비교하였다. 그 결과, 두 시스템이 평균오차와 표준편차가 1~2cm 수준으로 유사한 성능을 보였다.

• The Journal of Korean Physical Therapy
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• 제29권1호
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• pp.33-38
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• 2017

Purpose: This study was conducted to investigate the effects of variations in arm swing during gait on movement of the trunk and pelvis. During the gait task, the angle of the trunk and pelvic rotation were analyzed according to arm swing conditions. Methods: Seventeen healthy males participated in this study. All subjects were analyzed for gait on a treadmill three times each under three different types of arm swing conditions - natural arm swing, restricted arm swing using a phone, restricted swing in both arms. 3-D motion analysis systems were used to collect and analyze the kinematic data of trunk and pelvic movements, and repeated one-way ANOVA was used to compare the trunk and pelvic kinematic data and symmetry index. The level of significance was ${\alpha}=0.05$. Results: The results showed kinematic differences in trunk and pelvic during gait based on the arm swing conditions. Specifically, there were significant differences in trunk rotation, left and right trunk rotation and symmetry index of trunk rotation during gait among the three arm swing conditions. ROM was used to calculate a symmetry index (SI) based on the average left and right trunk rotation in which a value closer to zero indicated better balance. The SI obtained for arm swing restricted with the phone was closer to -1 than the other conditions. Conclusion: Restricted arm swing due to use of a phone had the possibility to induce instability of postural control while walking, which could be seen to suggest a risk of falling during gait.

• 한국자동차공학회논문집
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• 제6권3호
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• pp.169-176
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• 1998

A method for the dynamic analysis of multibody systems undertaking impulsive force is introduced in this paper. A partial velocity matrix based on Kane's method is introduced to reduce the number of equations to be solved. Only minimum number of equations of motion can be obtained by using the partial velocity matrix. This reduces the computational effort significantly to obtain the dynamic response of the system. At the very moment of the impulse, instead of using the numerical integrator to solve the equations of motion, the impulse and momentum principle is used to obtain the dynamic response. The impulse as wall as the reaction force acting on the kinematic joints can easily calculated too.

• 대한기계학회논문집A
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• 제21권8호
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• pp.1311-1321
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• 1997

In multibody dynamics, differential and algebraic equations which can satisfy both equation of motion and kinematic constraint equation should be solved. To solve these equations, coordinate partitioning method and constraint stabilization method are commonly used. In the coordinate partitioning method, the coordinates are divided into independent and dependent and coordinates. The most typical coordinate partitioning method are LU decomposition, QR decomposition, and SVD (singular value decomposition). The objective of this research is to find an efficient coordinate partitioning method in the dynamic analysis of flexible multibody systems. Comparing two coordinate partitioning methods, i.e. LU and QR decomposition in the flexible multibody systems, a new hybrid coordinate partitioning method is suggested for the flexible multibody analysis.

• International Journal of Automotive Technology
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• 제8권6호
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• pp.713-722
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• 2007

Design variables for suspension systems cannot always be realized in the actual suspension systems due to tolerances in manufacturing and assembly processes. In order to deal with these tolerances, design variables associated with kinematic configuration and compliance characteristics of suspensions are treated as random variables. The reliability of a design target with respect to a design variable is defined as the probability that the design target is in the acceptable design range for all possible values of the design variable. To compute reliability, the limit state, which is the boundary between the acceptable and unacceptable design, is expressed mathematically by a limit state function with value greater than 0 for acceptable design, and less than 0 for unacceptable design. Through reliability analysis, the acceptable range of design variables that satisfy a reliability target is specified. Furthermore, through sensitivity analysis, a general procedure for optimization of the design target with respect to the design variables has been established.