C. Jiang^1,2, S. Yu¹, H.C. Xie¹, B.C. Li¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.4, pp. 443-467, 2014, DOI:10.3970/cmes.2014.098.443

Abstract Based on the interval analysis method, this paper proposes an uncertain optimization model for the ride comfort in vehicles and achieves the optimal design of vehicle ride comfort under the condition of complicated uncertainty. The spring stiffness and shock absorber damping of suspension is regarded as the design parameters, while the root mean square (RMS) of the vehicle body acceleration is treated as the design objective and the corresponding constraints are composed of suspension stiffness, natural frequency and RMS of suspension dynamic deflection. Moreover, the uncertainties of key parameters, such as sprung mass, tire stiffness, vehicle speed and road roughness,… More >

Jia Dongyao^1,2, Zhu Huaihua¹, Ai Yanke¹, Zou Shengxiong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.103, No.6, pp. 411-427, 2014, DOI:10.3970/cmes.2014.103.411

Abstract The existing study on the image segmentation methods based on the image of vehicle lights is insufficient both at home and abroad, and its segmentation efficiency and accuracy is low as well. On the basis of the analysis of the regional characteristics of vehicle lights and a level set model, an image segmentation method for complex vehicle lights based on adaptive significance level set contour model is proposed in this paper. Adaptive positioning algorithm of the significant initial contour curve based on two-dimensional convex hull is designed to obtain the initial position of evolution curve, thus the adaptive ability of… More >

Christian Boe, Jose Rodriguez, Carlos Plazaola, Ilka Banfield A maly Fong, Rony Caballero, Adan Vega

CMES-Computer Modeling in Engineering & Sciences, Vol.90, No.2, pp. 165-177, 2013, DOI:10.3970/cmes.2013.090.165

Abstract The authors have developed a remote operate vehicle (ROV) that allow carried out highly risky task, in confined space such as inside of submerged sewers and pipes systems, areas were commercial ROV may not provide good performing. In addition, this ROV is low cost. This paper analyses based on the computational fluid dynamic the hydrodynamic performance of this ROV. The first part of the paper presents the theoretical approach and introduces the finite volume model developed in order to complete the study. Results of the model compare with published research shows good agreement. The second (forthcoming) part of the paper… More >

Yonghua Zhou¹, Xun Yang¹, Chao Mi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.89, No.6, pp. 497-512, 2012, DOI:10.3970/cmes.2012.089.497

Abstract The movements of vehicles equipped with various positioning systems such as global and wireless positioning ones have provided beneficial channels to acquire abundant traffic flow information for total road network. However, not all vehicles are mounted with positioning systems and not all equipped positioning facilities are always active. This paper will address how to estimate the number and the states of unequipped vehicles through a series of observations on equipped ones. The proposed estimation process initiates employing the non-analytical microscopic traffic model for particle filter to estimate the number, positions and speeds of unequipped vehicles between an equipped one and… More >

Hideki Fujii¹, Shinobu Yoshimura¹

CMES-Computer Modeling in Engineering & Sciences, Vol.88, No.1, pp. 49-64, 2012, DOI:10.3970/cmes.2012.088.049

Abstract Recently, global warming issues have been discussed all over the world. Of the total amount of CO₂ emitted in Japan, a transportation sector is responsible for 20%. In the transportation sector, 90% of the emission is due to road traffic. This amount must be reduced drastically to realize a low-carbon society. To do so, various measures have been discussed, and the effects of the measures must be estimated quantitatively. In conventional measurement methods, the amount of vehicle emission is simply calculated by multiplying travel distance or gasoline consumption by a specified emission coefficient. Such an approach neglects the effects of… More >

S. Rajagopal¹, Ranjan Ganguli²

CMES-Computer Modeling in Engineering & Sciences, Vol.81, No.1, pp. 1-34, 2011, DOI:10.3970/cmes.2011.081.001

Abstract The preliminary wing design of a low speed, long endurance UAV is formulated as a two step optimization problem. The first step performs a single objective aerodynamic optimization and the second step involves a coupled dual objective aerodynamic and structural optimization. During the first step, airfoil geometry is optimized to get maximum endurance parameter at a 2D level with maximum thickness to chord ratio and maximum camber as design variables. Leading edge curvature, trailing edge radius, zero lift drag coefficient and zero lift moment coefficient are taken as constraints. Once the airfoil geometry is finalized, the wing planform parameters are… More >

N. Liu,¹,W. Gao ¹, C.M. Song¹, N. Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.2, pp. 79-102, 2011, DOI:10.3970/cmes.2011.072.079

Abstract This paper presents the probabilistic dynamic analysis of vehicle-bridge interaction systems. The bridge's and vehicle's parameters are considered as random variables as well as the road surface roughness is modeled as random process. A two-degree-of-freedom spring-mass system is used to represent a moving vehicle and the bridge is modeled as an Euler-Bernoulli beam. From the equation of motion for the vehicle-bridge coupling system, the expressions for mean value and standard deviation of bridge response are developed by using the random variable's functional moment method. The effects of the individual system parameters and the road surface roughness on the bridge response… More >

Yongsheng Lian ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.1, pp. 1-16, 2011, DOI:10.3970/cmes.2011.072.001

Abstract In this paper we simulate the unsteady, incompressible, and laminar flow behavior over a flat plate with round leading and trailing edges. A pressure-Poisson method is used to solve the incompressible Navier-Stokes equations. Both convection and diffusion terms are discretized using a second-order accurate central difference method. A second-order accurate split-step scheme with an Adam's predictor corrector time-stepping method is adopted for the time integration. An overlapping moving grid approach is employed to dynamically update the grid due to the plate motion. The effects of the pitch rate, Reynolds number, location of pitch axis, and computational domain size are investigated.… More >

M. Trikha¹, S. Gopalakrishnan², D. Roy Mahapatra^2,1, R. Pandiyan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.45, No.2, pp. 97-140, 2009, DOI:10.3970/cmes.2009.045.097

Abstract A mechanics based linear analysis of the problem of dynamic instabilities in slender space launch vehicles is undertaken. The flexible body dynamics of the moving vehicle is studied in an inertial frame of reference, including velocity induced curvature effects, which have not been considered so far in the published literature. Coupling among the rigid-body modes, the longitudinal vibrational modes and the transverse vibrational modes due to asymmetric lifting-body cross-section are considered. The model also incorporates the effects of aerodynamic forces and the propulsive thrust of the vehicle. The effects of the coupling between the combustion process (mass variation, developed thrust… More >

Qiping Chen¹, Yu Liu¹, Liping Zeng¹, Qiang Xiao¹, Conghui Zhou¹, Sheng Kang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.14, No.4, pp. 281-291, 2018, DOI:10.32604/fdmp.2018.03721

Abstract The brake-by-wire system requirement is promoted owing to the development of green energy vehicle, and the brake pressure control method is needed. A control method for the master cylinder hydraulic pressure based on the sliding mode control approach is proposed to provide the Electro-Hydraulic Brake system (EHB) of electric vehicles with superior system performances. An assessment is carried out about the complex nonlinear characteristics and sensitivity to the external environment of these systems, which include illustrating the working principle of the EHB system, establishing the dynamic models of the key components of the EHB system. The sliding mode control method… More >