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Physical Parameter Identification Method Based on Modal Analysis for Two-axis On-road vehicles:Theory and Simulation

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Chinese Journal of Mechanical Engineering 2016年第4期29卷 756-764页

作者： ZHENG Minyi ZHANG Bangji ZHANG Jie ZHANG Nong State key laboratory of advanced design and manufacture for vehicle body Hunan University

Physical parameters are very important for vehicle dynamic modeling and ***,most of physical parameter identification methods are assuming some physical parameters of vehicle are known,and the other unknown parameters can be *** order to identify physical parameters of vehicle in the case that all physical parameters are unknown,a methodology based on the State Variable Method（SVM） for physical parameter identification of two-axis on-road vehicle is *** modal parameters of the vehicle are identified by the SVM,furthermore,the physical parameters of the vehicle are estimated by least squares *** numerical simulations,physical parameters of Ford Granada are chosen as parameters of vehicle model,and half-sine bump function is chosen to simulate tire stimulated by impulse *** first numerical simulation shows that the present method can identify all of the physical parameters and the largest absolute value of percentage error of the identified physical parameter is 0.205%;and the effect of the errors of additional mass,structural parameter and measurement noise are discussed in the following simulations,the results shows that when signal contains 30 d B noise,the largest absolute value of percentage error of the identification is 3.78%.These simulations verify that the presented method is effective and accurate for physical parameter identification of two-axis on-road *** proposed methodology can identify all physical parameters of 7-DOF vehicle model by using free-decay responses of vehicle without need to assume some physical parameters are known.

关键词： Parameter identification free-decay response state variable method modal parameter physical parameter

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A MESH-FREE ALGORITHM FOR DYNAMIC IMPACT ANALYSIS OF HYPERELASTICITY

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Acta Mechanica Solida Sinica 2013年第4期26卷 362-372页

作者： De’an Hu Zhanhua Sun Chao Liang Xu Han State key laboratory of advanced design and manufacture for vehicle body Hunan University

A mesh-free method based on local Petrov-Galerkin formulation is presented to solve dynamic impact problems of hyperelastic *** the present method,a simple Heaviside test function is chosen for simplifying domain *** function is constructed by using a radial basis function （RBF） coupled with a polynomial basis function,in which the shape function possesses the kronecker delta function ***,additional treatment is not required for imposing essential boundary *** equations of impact problems are established and solved node by node by using an explicit time integration algorithm in a local domain,which is very similar to that of the collocation method except that numerical integration can be implemented over local domain in the present *** results for several examples show that the present method performs well in dealing with the dynamic impact problem of hyperelastic material.

关键词： mesh-free method dynamic impact problem hyperelasticity explicit algorithm

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A decoupled method for time-dependent reliability-based design optimization

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Science China Technological Sciences 2025年第1期 312-324页

作者： Dequan ZHANG Meide YANG Xu HAN State key laboratory of Reliability and Intelligence of Electrical Equipment School of Mechanical EngineeringHebei University of Technology State key laboratory of advanced design and Manufacturing for vehicle body College of Mechanical and Vehicle EngineeringHunan University

Time-dependent reliability-based design optimization(TRBDO) has received extensive attention because of its ability to achieve optimal solutions that help meet the requirement for whole lifecycle reliability by quantitatively considering dynamic uncertainties. However, directly solving TRBDO problems is computationally expensive, if not prohibitive, owing to the need to repeatedly evaluate time-dependent probabilistic constraints. To address this challenge, an efficient decoupled method called sequential optimization and time-dependent reliability assessment(SOTRA) is proposed in this study. This method transforms the original TRBDO problem, initially formulated probabilistically, into a problem using percentile formulation after discretizing time-dependent performance functions. By adopting the equivalent minimum performance target point(EMPTP) concept, the TRBDO problem is further converted into an equivalent deterministic optimization problem, which is subsequently solved through a sequential iteration process involving deterministic optimization and time-dependent reliability analysis. To efficiently and robustly search an EMPTP for reliability analysis, a time-dependent self-adaptive finite-step length method is developed. To verify the proposed SOTRA method against existing TRBDO methods, a numerical example, a benchmark structural design case of a simply supported beam, and an engineering application for flexible wheel design are exemplified in this study. The results demonstrate that the proposed SOTRA method exhibits high efficiency and robustness in solving TRBDO problems.

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vehicle roll stability control with active roll-resistant electro-hydraulic suspension

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Frontiers of Mechanical Engineering 2020年第1期15卷 43-54页

作者： Lijun XIAO Ming WANG Bangji ZHANG Zhihua ZHONG State key laboratory of advanced design and manufacture for vehicle body Hunan UniversityChangsha 410082China

This study examines roll stability control for vehicles with an active roll-resistant electro-hydraulic suspension(RREHS)subsystem under steering ***,we derive a vehicle model with four degrees of freedom and incorporates yaw and roll ***,an optimal linear quadratic regulator controller is obtained in consideration of dynamic vehicle ***,an RREHS subsystem with an electric servo-valve actuator is proposed,and the corresponding dynamic equations are ***,field experiments are conducted to validate the performance of the vehicle model under sine-wave and double-lane-change steering ***,the effectiveness of the active RREHS is determined by examining vehicle responses under sine-wave and double-lane-change *** enhancement in vehicle roll stability through the RREHS subsystem is also verified.

关键词： electro-hydraulic suspension roll stability LQR experiment

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Non-random vibration analysis for general viscous damping systems

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Chinese Journal of Aeronautics 2019年第12期32卷 2655-2666页

作者： Chao JIANG Long LIU Jinwu LI Bingyu NI State key laboratory of advanced design and Manufacturing for vehicle body College of Mechanical and Vehicle Engineering Hunan University

The authors recently developed a kind of non-probabilistic analysis method, named as‘non-random vibration analysis’, to deal with the important random vibration problems, in which the excitation and response are both given in the form of interval process rather than stochastic process. Since it has some attractive advantages such as easy to understand, convenient to use and small dependence on samples, the non-random vibration analysis method is expected to be an effective supplement of the traditional random vibration theory. In this paper, we further extend the nonrandom vibration analysis into the general viscous damping system, and formulate a method to calculate the dynamic response bounds of a viscous damping vibration system under uncertain excitations. Firstly, the unit impulse response matrix of the system is obtained by using a complex mode superposition method. Secondly, an analytic formulation of the system dynamic response middle point and radius under uncertain excitations is derived based on the Duhamel’s integral, and thus the upper and lower response bounds of the system can be obtained. Finally, two numerical examples are investigated to demonstrate the effectiveness of the proposed method.

关键词： Complex mode Dynamic response bounds Interval process Random vibration Viscous damping system

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Fretting instability characteristics for gear shaft shoulder

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Journal of Central South University 2014年第10期21卷 3746-3752页

作者：贾国海龚金科鄂加强蔡皓王曙辉 State key laboratory of advanced design and Manufacturing for vehicle body (Hunan University)

In order to solve fretting instability problem of gear shaft shoulder due to torsional vibration in mechanical system, the mathematical model of fretting instability vibration of gear shaft shoulder was established by adopting the method of combining kinematics and tribology, and the numerical analysis was applied to the fretting instability mechanism of gear shaft shoulder by introducing the friction instability damping ratio. The numerical results show that the main factors causing the unstable and vibrating gear shaft shoulder are the large tightening torque and too large static friction coefficient. The reasonable values of the static friction coefficient, the amount of interference and tightening torque can effectively mitigate the fretting instability phenomenon of gear shaft shoulder. The experimental results verify that damping plays a significant role in eliminating the vibration of gear shaft control system.

关键词： gear shaft shoulder torsional vibration kinematics fretting friction instability damping ratio

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NUMERICAL SIMULATION ANALYSIS OF EXTERNAL FLOW FIELD OF WAGON-SHAPED CAR AT THE MOMENT OF PASSING

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Chinese Journal of Mechanical Engineering 2008年第4期21卷 76-80页

作者： GU Zhengqi HE Yibin ZHOU Wei JIANG Bo State key laboratory of advanced design and manufacture for vehicle body Hunan University Changsha 410082 China Hunan Province Institute of Science ＆ technology Changsha 410004 China

In the course of studying on aerodynamic change and its effect on steering stability and controllability of an automobile in passing, because of multi interaction streams, it is difficult to use traditional methods, such as wind tunnel test and road test. If the passing process of an automobile is divided into many time segments, so as to avoid the use of moving mesh which takes large calculation resource and CPU processing time in calculating, the segments are simulated with computational fluid dynamics （CFD） method, then the approximate computational results about external flow field will be obtained. On the basis of the idea, the change of external flow field of wagon-shaped car at the moment of passing is simulated through solving three-dimensional, steady and uncompressible N-S equations with finite volume method. Numerical simulation analysis of side force coefficient, stream lines, body surface pressure distribution of wagon-shaped car are presented and a preliminary discussion of aerodynamic characteristics of correlative situations is obtained. Finally, the C3 -x/l curve of side force coefficient（C3） of car following relative distance （x/l） between cars is obtained. By comparison, the curve is coincident well with the experimental data, which shows creditability of numerical simulation methods presented.

关键词： External flow field Passing Numerical simulation Side force coefficient

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Real-time lane departure warning system based on principal component analysis of grayscale distribution and risk evaluation model

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Journal of Central South University 2014年第4期21卷 1633-1642页

作者：张伟伟宋晓琳张桂香 State key laboratory of advanced design and Manufacturing for vehicle body (Hunan University)

A technology for unintended lane departure warning was proposed. As crucial information, lane boundaries were detected based on principal component analysis of grayscale distribution in search bars of given number and then each search bar was tracked using Kalman filter between frames. The lane detection performance was evaluated and demonstrated in ways of receiver operating characteristic, dice similarity coefficient and real-time performance. For lane departure detection, a lane departure risk evaluation model based on lasting time and frequency was effectively executed on the ARM-based platform. Experimental results indicate that the algorithm generates satisfactory lane detection results under different traffic and lighting conditions, and the proposed warning mechanism sends effective warning signals, avoiding most false warning.

关键词： lane departure warning system lane detection lane tracking principal component analysis risk evaluation model ARM-based real-time system

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Electric and magnetic dipole couplings in split ring resonator metamaterials

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Chinese Physics B 2011年第11期20卷 222-227页

作者：樊京孙光永朱卫仁 Department of Electronics and Electrical Engineering Nanyang Institute of Technology State key laboratory of advanced design and manufacture for vehicle body Hunan University Department of Applied Physics Northwestern Polytechnical University

In this paper, the electric and the magnetic dipole couplings between the outer and the inner rings of a single split ring resonator （SRR） are investigated. We numerically demonstrate that the magnetic resonance frequency can be substantially modified by changing the couplings of the electric and magnetic dipoles, and give a theoretical expression of the magnetic resonance frequency. The results in this work are expected to be conducive to a deeper understanding of the SRR and other similar metamaterials, and provide new guidance for complex metamaterials design with a tailored electromagnetic response.

关键词： metamaterials split ring resonator coupling

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A frequency domain reliability analysis method for electromagnetic problems based on univariate dimension reduction method

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Science China(Technological Sciences) 2019年第5期62卷 787-798页

作者： PING MengHao HAN Xu JIANG Chao ZHONG JianFeng XIAO XiaoYa HUANG ZhiLiang WANG ZhongHua State key laboratory of advanced design and Manufacturing for vehicle body College of Mechanical and Vehicle EngineeringHunan University Nanjing Research Institute of Electronics technology

In this paper, a class of electromagnetic field frequency domain reliability problem is first defined. The frequency domain reliability refers to the probability that an electromagnetic performance indicator can meet the intended requirements within a specific frequency band, considering the uncertainty of structural parameters and frequency-variant electromagnetic *** then a frequency domain reliability analysis method based on univariate dimension reduction method is proposed, which provides an effective calculation tool for electromagnetic frequency domain reliability. In electromagnetic problems, performance indicators usually vary with frequency. The method firstly discretizes the frequency-variant performance indicator function into a series of frequency points' functions, and then transforms the frequency domain reliability problem into a series system reliability problem of discrete frequency points' functions. Secondly, the univariate dimension reduction method is introduced to solve the probability distribution functions and correlation coefficients of discrete frequency points' functions in the system. Finally, according to the above calculation results, the series system reliability can be solved to obtain the frequency domain reliability, and the cumulative distribution function of the performance indicator can also be obtained. In this study,Monte Carlo simulation is adopted to demonstrate the validity of the frequency domain reliability analysis method. Three examples are investigated to demonstrate the accuracy and efficiency of the proposed method.

关键词： electromagnetic field frequency domain reliability system reliability random process discretization univariate dimension reduction method

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