• Journal of Biosystems Engineering
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• v.22 no.4
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• pp.421-432
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• 1997

This study was conducted to investigate dynamic characteristics of agricultural tractor with a particular interest in ride vibrations when it is subjected to various excitation forces. As the first part of it this paper describes development of dynamic model of a tractor-trailer system and its equations of motions. An 3 dimensional 16-degree-of-freedom dynamic model for a tractor-trailer system was developed and its equations of motions were derived, which will be used to investigate the effects of irregular ground surface and excitation forces due to the engine mounted on the tractor. And the excitation forces were also formulated analytically. The transition matrix method and QR algorithm were proposed for numerical solution of the equation of motions fur the developed model. The later parts of the study will include a proof of the model and optimization from which tractors can be designed to minimize the ride vibrations. This will be presented in the second and third papers to be followed shortly.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.2
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• pp.15-22
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• 2000

Shock and vibration characteristics of a tractor-trailer type vehicle system with air suspension and air coupler running on a single bump road are investigated. The vehicle system is modelled and solved to two types of models, i.e. rigid-multi-body and flexible-multi-body model, by ADAMS and NASTRAN software. And the shock impulse is given by a single bump model on the road. When the analysis results of the rigid-multi-body model is compared with those of the flexible-multi-body model, it is revealed that the vibration and accelerations of the latter model are more repetitive and larger than the former.

• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.1
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• pp.13-19
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• 2001

It is known that displacements, velocities and accelerations of the tractor- trailer type vehicle system in shock & vibration analysis by the flexible-multi-body dynamics including the flexibility of structure are bigger and more repetitive than them by the rigid-multi-body dynamics, and it is necessary to prove above results by the experimental field test. Therefore, in this paper, theoretical analysis by the flexible-multi-body dynamics and experimental field test for a tractor-trailer type vehicle system are conducted and their results are compared with each other. Because of unexpected metal contact and impact in the air coupler part in the field test, some accelerations measured from the experimental field test are bigger than them analyzed from the theoretical analysis, but most accelerations are well coincide with each other in the amplitudes and trends. Thus more refined dynamic analytical models for some special type vehicle systems will be possible in the future.

• Journal of Biosystems Engineering
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• v.23 no.6
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• pp.549-560
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• 1998

The dynamic model of a tractor-trailer system developed in the first part of this paper was verified in this article by comparing the simulated acceleration responses of the system with actually measured ones. A commercially available tractor and a trailer were used for the verification test. Values of the model parameters were measured or theoretically derived if the measurement was practically impossible. The tractor-trailer system was operated with different forward speeds over three equally spaced half-sine bumps on the flat concrete surface. Results of the verification tests showed that autospectra of the measured and simulated accelerations of the tractor-trailer system agreed well up to the frequencies slightly feater than the fundamental frequencies of the ground excitations and at the frequencies of engine excitations. The mean of normalized errors of the simulated responses to the measured ones was estimated to be less than 10% for all the test runs. The peak responses in the autospectra also coincided well both in the frequency and magnitude.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.230-231
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• 2008

본 논문은 KRRI 전륜 조향 차량의 횡 방향 동역학 모델링에 대한 내용을 기술한다. 이 차량은 굴절버스 형태를 갖고 모든 차륜의 조항이 가능하며 트레일러와 트랙터의 후륜이 독립적으로 구동 가능한 시스템을 갖고 있다. 이 시스템의 모델링은 비선형 동역학 방정식을 유도하고 선형화 한 뒤 횡 방향 동역학 모델만을 분리해서 최종적으로 횡 방향 선형 동역학 모델을 유도하는 과정을 거친다. 마지막으로 시뮬레이션을 통해 선형 모델을 검증한다.

• Journal of Biosystems Engineering
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• v.15 no.4
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• pp.298-309
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• 1990

A mathematical model was developed to simulate sideways overturning of agricultural tractor-trailer systems. Sideways overturn of a tractor-trailer system was described by oscillatory motions of the tractor with respect to the first and second tipping axes, and of the trailer with respect to the drawbar hitch point when either the tractor or trailer rides over an obstacle on slopes. By a computer simulation, critical slope angles of the ground on which the tractor-trailer system is likely to sideways overturn were evaluated under the given operational conditions. Validity of the proposed mathematical model was proved by comparing the results of computer simulation and experiment with a model tractor-trailer system. A close agreement was observed between the two results.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1549-1550
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• 2008

KRRI 바이모달 트램은 굴절버스 형태로 모든 차륜이 조향 가능하며 트레일러의 차륜과 트랙터의 후륜이 독립적으로 구동 가능한 시스템이다. 본 논문은 굴절차량용 자동 안내/추진 제어기를 설계하기 위한 차량의 동역학 분석 및 제어기의 성능분석용 Toolbox를 소개한다.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.9
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• pp.717-722
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• 2001

This paper presents a methodology on the backward path tracking control of a trailer type robot which consists of two parts: a tractor and a trailer. It is difficult to control the motion of a trailer vehicle since its dynamics is non-holonomic. Therefore, in this paper, the modeling and parameter estimation of the system using a real-coded genetic algorithm(RCGA) is proposed and a backward path tracking control algorithm is then obtained based on the linearized model. Experimental results verify the effectiveness of the proposed method.

• Journal of Korean Society of Steel Construction
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• v.12 no.1 s.44
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• pp.103-110
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• 2000

The suspension bridge is divided by an earth anchor and a self-anchor type according to the anchorage type. This study is to evaluate the dynamic effect of moving vehicles to suspension bridges. The results were presented with the dynamic magnification factor (DMF) by the effect of vehicle speed and weight according to the anchorage type. The vehicle model has 6 degrees of freedom to idealize nonlinear multi-leaf suspensions and elastic tires of tractor-trailer. The bridge was modelled with the 3-dimensional frame element and 3-dimensional elastic catenary cable element. The condition of deck surface is considered using the actual road spectra.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.187-196
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• 2010

The purpose of this study is to develop the calibration method for temperature effects to improve the accuracy of the Weigh-In-Motion(WIM) system for collecting long-term truck weight data. WIM system was installed at a location where the truck traffic volume is high and weight data has been collected from January 2010. In this study, as a calibration measure, the first axle weight of Truck Type 10, the semi tractor-trailer is used based on the fact that the first axle weight is relatively constant, independent of the cargo weight. From this fact, calibration equations are developed from the relationship between the axle weight and the temperature(daily mean, maximum and minimum). Analysis on calibrated weight data shows adequacy of the proposed calibration method. Results of this study can be used to improve the accuracy of the WIM system and to carry out more rational design of pavement and bridge structures.