• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.9
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• pp.1003-1008
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• 2012

The paper presents an Experimental Vehicle Model (EVM), that utilizes the kinematic characteristics of suspensions from SPMD test data. The relative displacement and orientation of a wheel with respect to the body are represented as a function of the vertical displacement of the wheel. The equations of motion of the vehicle are formulated in terms of local coordinates that do not require coordinate transformation, which improves the efficiency of dynamic analysis. The EOM was modularized for each suspension model, and a $6{\times}6$ vehicle model was obtained by combining six suspensions. The analysis results were compared with ADAMS to verify the accuracy of the EVM. This study also verifies the feasibility of real-time simulation with the developed EVM. For a vehicle simulation for 1 ms, the real simulation time required within 20% of the prescribed time. This result shows that the EVM meets the real-time simulation requirements.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.173-179
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• 2003

In this paper, a real-time multibody vehicle dynamics and control model has been developed for a virtual reality intelligent vehicle simulator. The simulator consists of low PCs for a virtual reality visualization system, vehicle dynamics and control analysis system a control loading system, and a network monitoring system. Virtual environment is created by 3D Studio Max graphic tool and OpenGVS real-time rendering library. A real-time vehicle dynamics and control model consists of a control module based on the sliding mode control for adaptive cruise control and a real-time multibody vehicle dynamics module based on the subsystem synthesis method. To verify the real-time capability of the model, cut-in, cut-out simulations have been carried out.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1714-1717
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• 2003

ECCOMAS Thematic Conference Multibody 2003 was held at IST (Instituto Superior Technico), Lisbon, Portugal from July 1 to July 4. 2003. And MBDV(Multibody Dynamics and Vibration) in the 2003 ASME DETC was held at Chicago, U.S.A. from September 2 to September 6. In this paper, the presented papers in these conferences were reviewed and the trends in the multibody dynamics are summarized. The session titles in these conferences include Flexible Multibody Dynamics, Vehicle Dynamics, Contact, Biomechanics, Real-time Challenges, Spatial manipulator and Control, Multidisciplinary Applications, and Advanced Education. The poster session was also organized for more discussions in the Multibody2003 conference.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.5
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• pp.834-840
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• 2001

A real time multibody vehicle dynamics model has been developed and implemented using a subsystem synthesis method based on recursive formulation. To verify real time simulation capability the developed model has been applied to HMMWV(High Mobility Multipurpose Wheeled Vehicle) with steering system. For the kinematically driven steering system, the coupled front suspension-steering subsystem can be decoupled into two SLA suspension subsystems, which improves the efficiency of simulation. To investigate theoretical efficiency, operational counting method has been also employed to compare the proposed model with the conventional recursive dynamics model. Various simulations such as unsymmetric bump run, step steering(J-turn) and sine steering input test have been carried out to verify the real time feasibility of the proposed model.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.6
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• pp.57-65
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• 2006

An approximate function approach has been developed using the subsystem synthesis method for real-time multibody vehicle dynamics models. In this approach, instead of solving loop closure constraint equations of the suspension linkage, approximate functions are used. The approximate function represents the functional relationship between dependent coordinates and independent coordinates of the suspension subsystem. This kinematic relationship is also included in the suspension subsystem equations of motion. Different order of polynomial functions are tried to find out the best candidate functions. The proposed method is also compared with the conventional subsystem synthesis method to verify its efficiency and accuracy.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.3
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• pp.486-494
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• 2001

This paper presents a real-time multibody vehicle dynamic analysis method using recursive Kanes formulation and suspension composite joints. To shorten the computation time of simulation, relative coordinate system is used and the equations of motion are derived using recursive Kanes formulation. Typical suspension systems of vehicles such as MacPherson strut suspension system is modeled by suspension composite joints. The joints are derived and utilized to reduce the computation time of simulation without any degradation of kinematical accuracy of the suspension systems. Using the develop program, a multibody vehicle dynamic model is formed and simulations are performed. Accuracy of the simulation results is compared to the real vehicle field test results. It is found that the simulation results using the proposed method are very accurate and real-time simulation is achieved on a computer with single PowerPC 604 processor.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.1
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• pp.169-175
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• 2009

Real-time multibody vehicle dynamics software has been developed for virtual handling tests. The software can be utilized for HILS(Hardware In the Loop Simulations) and consists of three modules such as a graphical vehicle modeling preprocessor, a real time dynamics solver, and a virtual reality graphic postprocessor for virtual handling tests. In the graphical vehicle modeling preprocessor, vehicle hard point data for a suspension model are automatically converted into multibody vehicle model. In the real time dynamics solver, the efficient subsystem synthesis method is used to create multibody equations of motion for a subsystem by a subsystem. In the virtual reality graphic postprocessor, an animator has been also developed by using Matlab Virtual Reality Toolbox for virtual handling tests.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.1
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• pp.162-168
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• 2009

The real-time multibody vehicle model based on the subsystem synthesis method has been developed. Suspension, anti roll bar, steering, and tire subsystem models have been developed for vehicle dynamics. The compliance effect from bush element has been considered using a quasi-static method to achieve the real time requirement. To validate the developed vehicle model, a quarter car and a full vehicle simulations have been carried out comparing simulation results with those from the ADAMS vehicle model. Real time capability has been also validated by measuring CPU time of the simulation results.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.4
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• pp.199-206
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• 2006

Real time vehicle dynamics models have been developed with the subsystem synthesis method for intelligent vehicle HILS system. Three different models for solving subsystem equations are compared in order to find out the best suitable model for HILS applications. The first model is based on the generalized coordinate partitioning technique, and the second one is on the approximate function approach, and the last one is on the constraint stabilization method. To investigate the theoretical efficiency of three proposed methods, arithmetic operators used in the formulations of three models are counted. Bump run simulations with half-sine bump have also carried out with three different models to measure the actual CPU time to validate theoretical investigation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.2
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• pp.157-165
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• 2016

In wartime conditionsmilitary combat vehicles are required to be driven on rough roads that have significant obstacles. A wheel type dog-horse robot with a rotary suspension system was applied to overcome the obstacles. To achieve real-time analysis, a simplified model was proposed by using velocity transformations. Through comparison with the multi-body dynamics model, the efficiency and accuracy of the proposed modeling was proven.