• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 춘계학술대회 논문집
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• pp.135-140
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• 2003

This paper is handling about comparative study on dynamic responses of tracked vehicle on soft soil. Two models of tracked vehicle are used in this paper: a single-body model and a multi-body model. Two different methods for dynamic analysis of tracked vehicle are compared: single-body dynamic analysis and multi-body dynamic analysis. Traveling performances of two tracked vehicles are compared.

• 한국지반공학회논문집
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• 제34권2호
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• pp.43-54
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• 2018

해저궤도차량은 큰 중량을 가지고 포화된 해저지반 위를 구동하며 작업을 수행한다. 해저궤도차량 구동 시 궤도-지반 접지면에서는 지반의 전단 및 침하현상이 발생되며, 이로 인해 각각 지반추력 및 지반저항력이 발현되어 구동성능을 제한한다. 즉, 일반적인 포장도로 주행차량과 달리, 해저궤도차량의 구동성능은 엔진성능뿐 아니라 주행하는 지반과 차량의 상호작용에 의해 결정되는 것이다. 본 연구에서는 궤도-지반 상호작용 이론을 바탕으로 해저궤도차량에 적용될 수 있는 다양한 지반특성(흙 종류, 상대밀도 혹은 경질도) 및 차량특성(차량중량 및 궤도시스템 제원)에 따른 구동성능 평가를 수행하였다. 그 결과, 해저궤도차량이 모래지반 및 실트질 모래지반에서 운용되는 경우에는 비교적 수월하게 구동성능을 확보할 수 있지만, 점성토 지반에서는 구동성능 확보에 어려움이 있을 것으로 나타났다. 특히, 점성토 지반에서 운용되는 해저궤도차량의 중량이 큰 경우 전반적인 구동성능 및 등판능력이 매우 떨어지는 것으로 평가되어, 구동성능을 확보하기 위한 추가적인 보안방안이 필요할 것으로 판단된다.

• 한국정밀공학회지
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• 제19권2호
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• pp.140-150
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• 2002

The planar tracked vehicle model used in this investigation consists of two kinematically decoupled subsystems, i.e., the chassis subsystem and the track subsystem. The chassis subsystem includes the chassis frame, sprocket, idler and rollers, while the track subsystem is represented as a closed kinematic chain consisting of rigid links interconnected by revolute joints. In this study, the recursive kinematic and dynamic formulation of the tracked vehicle is used to find the vertical terce and the distance of an arbitrary track moved in the driving direction along the track. These distances and vertical forces obtained are used to get the deformation and sinkage of a terrain. The FEM(Finite Element Method) is adopted to analyze the interaction between tracked vehicle and terrain. The terrain is represented by a system of elements wish specified constitutive relationships and considered as a piecewise linear elastic, plastic and isotropic material. When the tracked vehicle is moving with different speeds on the terrain, the elastic and plastic deformations and the maximum sinkage for the four different types of isotropic soils are simulated.

• Journal of Mechanical Science and Technology
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• 제14권10호
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• pp.1028-1040
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• 2000

A numerical method is presented for the dynamic analysis of military tracked vehicles of high mobility. To compute the impulsive dynamic contact forces which occur when a vehicle passes on a ground obstacle, the track is modeled as the combination of elastic links interconected by pin joints. The mass of each track link, the elastic elongation of a track link between pin joints by the track tension, and the elastic spring effects on the upper and lower surfaces of each track link have been considered in the equations of motion. And the chassis, torsion bar arms, and road wheels of the vehicle are modeled as the rigid multi bodies connected with kinematic constraints. The contact positions and the contact forces between the road wheels and track, and the ground and the the track are simultaneously computed with the solution of the equations of motions of the vehicle consisting of the multibodies. The iterative scheme for the solution of the multi body dynamics of the tracked vehicle is presented and the numerical simulations are conducted.

• 한국자동차공학회논문집
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• 제9권4호
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• pp.139-147
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• 2001

2 DOF half-car model with 6 semi-active suspension units is utilized to evaluate the tracked vehicle dynamic performance simulated by several suspension control algorithms. The target of this research is to improve the ride comfort to maintain operator's handling capability when the tracked vehicle travels fast on the rough road. The control algorithms for suspension systems, such as full state feedback active, full state feedback semi-active, sky-hook active, sky-hook semi-active, and on-off systems, are evaluated and analyzed in view point of ride comfort. The dynamic performances of vehicle are expressed and evaluated by vibratory characteristic evaluation curves, performance indices and frequency characteristic curves. The simulation results show that the performances of sky-hook algorithms for ride comfort nearly follow those of full state feedback algorithms and on-off algorithm is recommendatory when the vehicle runs relatively fast.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.174.1-174
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• 2001

The role of suspension system in tracked vehicles cannot be overestimated because the driving and running conditions of such vehicles are very severe. It reduces the vibration and shock which are generated by road profile in running condition. As the tracked vehicle's running speed increases, more undesired vibrations can be generated by road profile particularly in the situation of field running. Because, the excessive vibration can harm the operation ability of crewmen and stability of complex equipments, the maximum running speed is limited. In this study, to improve the performance of the tracked vehicle system, we examined the feasibility of using the active preview control for the tracked vehicle´s suspension system. First, we developed ...

• 한국자동차공학회논문집
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• 제7권6호
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• pp.248-257
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• 1999

A mathematical model was developed to investigate the mechanical interrelation between soil characteristics and main design factors of a tracked vehicles , and predict the tractive performance of the tracked vehicles. Based on the mathematical model, a computer simulation program(TPPMTV98) was developed in this study. The effectiveness of the developed model was verified by comparing the predicted drawbar pulls using TPPMTV98 with measured ones from traction tests with a tracked vehicle reconstructed for test in loam soil with moisture content of 18.92%(d.b). The drawbar pulls measured by the TPPMTV98 were well matched to the measured ones. Such results implied that the model developed in this study could estimate the drawbar pulls well at various soil conditions , and would be very useful as a simulation tool for designing a tracked vehicle and predicting its tractive performance.

• Ocean and Polar Research
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• 제32권4호
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• pp.361-367
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• 2010

The principal objective of this paper was to evaluate the steering characteristics of a tandem tracked vehicle, each side of which features two tandem tracks, when crawling on extremely cohesive soft soil. The tandem tracked vehicle is assumed to be a rigid-body with 6-dof. The dynamic analysis program of the tandem tracked vehicle was developed via Newmark's method and the incremental-iterative method. A terra-mechanics model of extremely cohesive soft soil was implemented according to the relationships of normal pressure to sinkage, of shear resistance to shear displacement, and of dynamic sinkage to shear displacement. In order to simplify the characteristics of contact interaction between track segments and cohesive soft soil, the characteristics of soil are equated to the properties of intact soil. In an effort to evaluate the steering characteristics of a tandem tracked vehicle crawling on extremely cohesive soft soil, a series of dynamic simulations were conducted for a tandem tracked vehicle model with respect to the front and rear steering angle, the steering ratio, and the initial velocity.

• 대한기계학회논문집A
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• 제23권11호
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• pp.1960-1969
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• 1999

This paper presents dynamic modeling and controller design of a tracked vehicle installed with the double rod type ERSU(electro-rheological suspension unit). A 16 degree-of-freedom model for the tracked vehicle is established by Lagrangian method followed by the formulation of a new sky-ground hook controller. This controller takes account for both the ride quality and the steering stability. The weighting parameter between the two performance requirements is adopted to adjust required performance characteristics with respect to the operation conditions such as road excitation. The parameter is appropriately determined by employing a fuzzy algorithm associated with the vehicle motion. Computer simulations are undertaken in order to demonstrate the effectiveness of the proposed control system. Acceleration values at the driver's seat are analyzed under bump road profile, while frequency responses of vertical acceleration are investigated under random road excitation.

• Structural Engineering and Mechanics
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• 제11권2호
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• pp.133-149
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• 2001

A high-fidelity model of a tracked vehicle traversing a flexible ground terrain with a varying profile is presented here. In this work, we employed a recursive formulation to model the track subsystem. This method yields a minimal set of coordinates and hence, computationally more efficient than conventional approaches. Also, in the vehicle subsystem, the undercarriage frame is assumed to be connected to the chassis by a revolute joint and a spring-damper unit. This increase in system mobility makes the model more realistic. To capture the vehicle-ground interaction, a Winkler-type foundation with springs-dampers is used. Simulation runs of the integrated tracked vehicle system for vibrations for four varying ground profiles are provided.