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The roll centre (RC) is a core parameter for vehicle lateral dynamics and control, which can be obtained via suspension geometry configuration or suspension kinematics and compliance (K&C) test. Ho...

In order to make full use of the direct yaw control (DYC) in electric vehicles with four in-wheel motors (IWMs), this paper presents an adaptive SMC control scheme to improve the handling and stabi...

The performance of velocity & displacement-dependent damper (VDD), inspired by the semi-active control, is analyzed. The main differences among passive, displacement-dependent and semi-active dampers are compared on their damping properties. Valve assemblies of VDD are modelled to get an insight into its working principle. The mechanical structure composed by four valve assemblies helps to enable VDD to approach the performance by those semi-active control dampers. The valve structure parameters are determined by the suggested two-step process. Hydraulic model of the damper is built with AMEsim. Simulation result of F-V curves, which is similar to those of semi-active control damper, demonstrates that VDD could achieve the similar performance of semi-active control damper. The performance of a quarter vehicle model employing VDD is analyzed and compared with semi-active suspension. Simulation results show that VDD could perform as good as a semi-active control damper. In addition, no add-on hardware or energy consumption is needed for VDD to achieve the remarkable performance.

This paper presents a novel nonlinear dynamic model of a multi-axle steering vehicle to estimate the lateral wear amount of tires. Firstly, a 3DOF nonlinear vehicle dynamic model is developed, including dynamic models of the hydropneumatic suspension, tire, steering system and toe angle. The tire lateral wear model is then built and integrated into the developed vehicle model. Based on the comparison of experimental and simulation results, the nonlinear model is proved to be better than a linear model for the tire wear calculation. In addition, the effects of different initial toe angles on tire wear are analyzed. As simulation results shown, the impact of the dynamic toe angle on the tire wear is significant. The tire wear amount will be much larger than that caused by normal wear if the initial toe angle increases to 1° - 1.5°. The results also suggest that the proposed nonlinear model is of great importance in the design and optimazation of vehicle parameters in order to reduce the tire wear.

The path following and directional stability are two crucial problems when a road vehicle experiences a tire blow-out or sudden tire failure. Considering the requirement of rapid road vehicle motion control during a tire blow-out, this article proposes a novel linearized decoupling control procedure with three design steps for a class of second order multi-input-multi-output non-affine system. The evaluating indicators for controller performance are presented and a performance related control parameter distribution map is obtained based on the stochastic algorithm which is an innovation for non-blind parameter adjustment in engineering implementation. The analysis on the robustness of the proposed integrated controller is also performed. The simulation studies for a range of driving conditions are conducted, to demonstrate the effectiveness of the proposed controller.

For vehicle rollover control systems, an accurate and predictive rollover index is necessary for a precise rollover threat detection and rollover prevention. In this paper, the contour line of load transfer ratio (CL-LTR) and the CL-LTR-based vehicle rollover index (CLRI) are proposed, describing LTR threshold and LTR change rate precisely, providing an accurate prediction of vehicle rollover threat. In detail, the CL-LTR is proposed via the roll dynamics phase plane analysis, and its analytical solution of one-degree-of-freedom vehicle roll model and extension for full vehicle are derived. Moreover, the predictive CLRI is proposed and evaluated via vehicle dynamics study. The results demonstrate that vehicle rollover threat is predicted accurately based on the CLRI, which shows benefits for the vehicle rollover prediction and stability control.

Scissor seat suspension has been applied widely to attenuate the cab vibrations of commercial vehicles, while its design generally needs a trade-off between the seat acceleration and suspension travel, which creates a typical optimisation issue. A complexity for this issue is that the optimal dynamics parameters are not easy to approach solutions fast and unequivocally. Hence, the hierarchical optimisation on scissor seat suspension characteristic and structure is proposed, providing a top-down methodology with the globally optimal and fast convergent solutions to compromise these design contradictions. In details, a characteristic-oriented non-parametric dynamics model of the scissor seat suspension is formulated firstly via databases, describing its vertical dynamics accurately. Then, the ideal vertical stiffness-damping characteristic is cascaded via the characteristic-oriented model, and the structure parameters are optimised in accordance with a structure-oriented multi-body dynamics model of...

This paper designs a membranous dual-cavity based amplitude sensitive damper (shorted as MASD) for road vehicle suspension to better compromise ride comfort and driving safety. A specially designed sleeve, separated into two cavities by a rubber membrane, is centrally placed along the main piston of conventional twin-tube damper. The volume change of dual-cavity caused by membrane deformation accommodates partial oil flow in the condition of small piston displacement, which results in a reduced damping ratio. Due to the attached rubber embossments on both sides of rubber membrane, this MASD can switch smoothly between low and high damping forces at the final stage of membrane deformation. This design prevents the damper from additional impact when switching between higher damping ratio to lower one. After elaborating the working principle of MASD, its dynamic model is derived by combining first-principle modeling of hydraulic components and empirical modeling of membranous valve. A prototyping MASD is finally developed and tested on a damper test rig to demonstrate its effectiveness.

This paper devotes analytical effort in developing the 2M equivalent approach to analyse both the effect of vehicle body roll and n-axle handling on vehicle dynamics. The 1M equivalent vehicle 2DOF equation including an equivalent roll effect was derived from the conventional two-axle 3DOF vehicle model. And the 1M equivalent dynamics concepts were calculated to evaluate the steady-state steering, frequency characteristics, and root locus of the two-axle vehicle with only the effect of body roll. This 1M equivalent approach is extended to a three-axle 3DOF model to derive similar 1M equivalent mathematical identities including an equivalent roll effect. The 1M equivalent wheelbases and stability factor with the effect of the third axle or body roll, and 2M equivalent wheelbase and stability factor including both the effect of body roll and the third-axle handling were derived to evaluate the steady-state steering, frequency characteristics, and root locus of the three-axle vehicle. By using the re...

Under the background of intelligent manufacturing, the application of industrial big data is the key to improve the utilization efficiency of manufacturing resources. Starting from the purpose of big data application and how to replace the efficiency of enterprise resource utilization, aiming at the construction of intelligent and transparent big data system in automobile factory, this paper combed the concept of big data system construction, discussed the construction ideas of big data system, constructed the big data system framework suitable for discrete manufacturing enterprises, and gave the methods of data acquisition, transmission, storage, processing and Analysis of the specific program. For big data applications, taking the enterprise intelligent operation cockpit, intelligent electronic process system and enterprise epidemic prevention and health cloud system as examples, the scene and application effect of big data application are demonstrated. The construction and application of big data system in intelligent and transparent automobile factory provides a reference model for further promoting intelligent manufacturing driven by big data.

Trajectory planning plays an important role in autonomous driving technology. This paper presents an improved Hybrid A* algorithm by considering vehicle dynamics in planning. First, a vehicle dynamic model with three degrees of freedom and a nonlinear UniTire tyre model are developed to describe the vehicle dynamics. Then, in order to generate curvature-continuous trajectory, the method of expanding nodes based on the rotation speed of steering wheel is introduced. Then, heuristic functions are designed for trajectory searching. In addition, the feasibility of the planning result is verified in the driver-vehicle-road closed loop system. Simulation results show the proposed trajectory planning method performs well under a variety of working conditions and the planned trajectory is trackable even at extreme conditions, e.g., high speed and low-adhesion road surfaces. Specifically, on the icy road, the planned results are good and the maximum lateral tracking error of this trajectory is limited to 0.24 m.

The current work is concerned with modelling and analysis for a pilot relief valve, thus successfully bringing a systematic method for designing and analyzing similar valves. The essence of the work is to solve two important problems, one for positions of the pilot valve influenced by flow force and the other is for the opening of the relief valve governed by a thin annular plate. The computational fluid dynamics (CFD) method is used to present the flow force. Using a series of experiments, the flow rate versus pressure drop shows the rationality of the CFD results. In order to obtain the opening of relief valve with higher accuracy, the large deflection theory of thin plates is adopted. An equivalent method for replacing the concentrated force is innovatively proposed so that all of the loads of the plates can be given by a unified expression, which reduces the number of the governing equations and intermediate boundary conditions. For presenting a very simple and reliable method for solving the governing equation, an unconstrained nonlinear optimization is innovatively introduced to solve the deflection of the thin annular plate. Being verified by finite-element method (FEM) of the relief valve, the equivalent method and optimization can solve deflection of thin plates rapidly and accurately. Reflected through a complete model for the pilot relief valve, the theoretical flow rate of the pilot relief valve is consistent with experimental conclusion. Once again, the comparisons bring us insight into the accuracy of the method adopted in the current work.

In order to improve the vehicle fuel economy, ride comfort and handling, this paper presents the design, modeling, and performance study of a novel hydraulic pumping regenerative suspension based on an energy recovery unit and a hydraulic actuator. It can harvest energy from suspension vibration and lessen damping oil temperature rising. In addition, variable damping force can be achieved by controlling the electrical load of the energy recovery unit, and proper asymmetric ratio of compression/extension damping force needed by traditional vehicles can be obtained via the special layout of this suspension. It shows that an optimal regenerative power 33.4 W can be obtained from each regenerative suspension via the GA optimization. The physical based model and parameter study in this paper can be used in the regenerative suspension semi-active controller design and the development of this novel hydraulic pumping regenerative suspension in the future.

In this paper, a reduced-order sliding mode observer (RO-SMO) is developed for vehicle state estimation. Several improvements are achieved in this paper. First, the reference model accuracy is improved by considering vehicle load transfers and using a precise nonlinear tyre model ‘UniTire’. Second, without the reference model accuracy degraded, the computing burden of the state observer is decreased by a reduced-order approach. Third, nonlinear system damping is integrated into the SMO to speed convergence and reduce chattering. The proposed RO-SMO is evaluated through simulation and experiments based on an in-wheel motor electric vehicle. The results show that the proposed observer accurately predicts the vehicle states.

A novel direct yaw moment controller is developed in this paper. A hierarchical control architecture is adopted in the controller design. In the upper controller, a driver model and a vehicle model are used to obtain the driver's intention and the vehicle states, respectively. The upper controller determines the desired yaw moment by means of sliding mode control. The lower controller distributes differential longitudinal forces according to the desired yaw moment. A nonlinear tyre model, ‘UniTire’, is utilised to develop the novel distribution strategy and the control boundary.

In this paper, an axisymmetric finite element (FE) model of an air spring was carried out with the software ABAQUS to design its target vertical stiffness. The bellows was simulated by the reinforced surface element. The compressed gas in the cavity of the air spring was represented by the hydrostatic fluid element. The target stiffness is obtained by modifying the valid area of the cross section. At last, the results of experiment coincided well with the simulation data. The study shows that the static stiffness of air spring is sensitive to the effective area of the cross section. The conclusion has certain practical significance for the design and the optimization of the same kind of air spring.

Based on the preview optimal simple artificial neural network driver model (POSANN), a new driver model, considering jerky dynamics and the tracing error between the real track and the planned path, is established. In this paper, the modeling for the driver-vehicle system is firstly described, and the relationship between weighting coefficients of driver model and system parameters is examined through test data. Secondly, the corresponding road test results are presented in order to verify the vehicle model and obtain the information on drive model and vehicle parameters. Finally, the simulations are carried out via CarSim. Simulation results indicate that the jerky dynamics need to be considered and the proposed new driver model can achieve a better path-following performance compared with the POSANN driver model.

This paper introduces a new pneumatic spring for vehicle suspension systems, allowing independent tuning of stiffness and ride height according to different vehicle operating conditions and driver preferences. The proposed pneumatic spring comprises a double-acting pneumatic cylinder, two accumulators and a tuning subsystem. This paper presents a detailed description of the pneumatic spring and its working principle. The mathematical model is established based on principles of thermo and fluid dynamics. An experimental setup has been designed and fabricated for testing and evaluating the proposed pneumatic spring. The analytical and experimental results confirm the capability of the new pneumatic spring system for independent tuning of stiffness and ride height. The mathematical model is verified and the capabilities of the pneumatic spring are further proved. It is concluded that this new pneumatic spring provides a more flexible suspension design alternative for meeting various conflicting suspension requirements for ride comfort and performance.

MR fluid squeeze mode investigations at CVeSS have shown that MR fluids show large force capabilities in squeeze mode. It was found that MR fluids in squeeze mode may be used in a wide range of applications such as engine mounts and impact dampers. In these applications, MR fluid is flowing in a dynamic environment due to the transient nature of inputs and system characteristics. The research presented in this article undertakes the problem of dynamic testing and modeling of MR fluid squeeze mounts. Dynamic tests of an MR mount are studied for different applied currents, initial gaps, frequencies, and excitation amplitudes. An effective mathematical model of the MR squeeze mount for steady-state testing was built which includes the effect of the inertia of the fluid. The results show that the compression force and the area of the hysteresis loop increase with the increase of excitation amplitude or applied current and it will decrease with the increase of frequency or initial gap. Also, the inertia effect becomes more significant for higher displacement frequencies. The mathematical model agrees with the test data very well during the compression process and it can be used for the dynamics analysis and the real-time control.

UniTire is a unified non-linear and non-steady tire model for vehicle dynamic simulation and control under complex wheel motion inputs, involving large lateral slip, longitudinal slip, turn-slip, and camber. The model is now installed in an ADSL driving simulator at Jilin University for studying vehicle dynamics and their control systems. In this paper, first, a brief history of UniTire development is introduced; then the application scope of UniTire and available interfaces to MBS software are presented; thirdly, a more detailed description of UniTire is given; fourthly, a tool aiming at parameterization of UniTire is also demonstrated; and finally, some comments on TMPT are made.

For evaluation of vehicle handling, subjective assessment is currently almost the only criterion. For the purpose of reducing cycle time and avoiding error of subjective assessment, the close-loop objective evaluation system through computer simulations has become an inevitable choice [Gwanghun, G.I.M. and Yongchul, C.H.O.I., 2001, Role of tire modeling on the design process of a tire and vehicle system. ITEC ASIA 2001, Busan, Korea, September 18–20; Guo, K., Ding, H., Zhang, J., Lu, J. and Wang, R., 2003, Development of longitudinal and lateral driver model for autonomous vehicle control. International Journal of Vehicle Design, 36(1), 50–65]. For this reason, the more accurate models of vehicle, tire and driver are necessary. Since structure and operating conditions of tires are very complicated, many researchers have paid more attention to the modeling of tire properties and varieties of tire model have been done to describe the tire behaviour of longitudinal, lateral forces and aligning moment [Pacejk...

Vehicle behaviors under extreme cornering are complex events that might result in rollover accidents. Simulations have been extensively used in the auto industry to protect vehicles from such accidents. Predictive capability of simulation relies on how accurate the math-based model represents the vehicle and its operating condition. Camber effects of tire are studied in this paper to promote the accuracy of simulation. First, a tire model with simplified camber effect is introduced, and the comparison between the model results and test data is shown. Then, a more precise model that includes camber effects on cornering stiffness are friction coefficient is presented. The comparison between these model results and test data is also given. In addition, the camber effects on tire overturning moment and loaded radius are studied. Finally, vehicle fishhook simulation with different tire models is conducted to further investigate the effect of tire camber on vehicle dynamics.

The UniTire model is a nonlinear and non-steady-state tyre model for vehicle dynamics simulation and control under complex wheel motion inputs involving large lateral slip, longitudinal slip, turn slip and camber. The model is now installed in the driving simulator in the Automobile Dynamic Simulation Laboratory at Jilin University for studying vehicle dynamics and their control systems. Firstly, the nonlinear semiphysical steady-state tyre model, which complies with analytical boundary conditions up to the third order of the simplified physical model, is presented. Special attention has been paid to the expression for the dynamic friction coefficient between the tyre and the road surface and to the modification of the direction of the resultant force under combined-slip conditions. Based on the analytical non-steady-state tyre model, the effective slip ratios and quasi-steady-state concept are introduced to represent the non-steady-state nonlinear dynamic tyre properties in transient and large-slip-ratio...

Hybrid powertrain has become the standard configuration of some automobile models. The test system of hybrid vehicle powertrain was developed based on virtual instrument, using electric dynamometer to simulate the work of engines, to test the motor and control unit of the powertrain. The test conditions include starting, acceleration, and deceleration. The results show that the test system can simulate the working conditions of the hybrid electric vehicle powertrain under various conditions.

A predictive current control scheme is adopted in this paper to improve the current tracking performance of Permanent Magnet Synchronous Motor in the Electric power steering system. But the motor parameters variation can lead to a steady-state error and reduce the stability margin of the current tracking system, even destabilize the system. So this paper presents an adaptive predictive current controller for Electric power steering system with Permanent Magnet Synchronous Motor, The controller is mainly composed of a cross-coupling compensator, a predictive current controller and an adaptive parameter estimator. The coupling compensator decouples the Permanent Magnet Synchronous Motor into two parallel SISO linear systems, the predictive current controller combined a two-sample deadbeat controller with a current predictor provides robustness against the control delay, and the adaptive identifier estimate the motor parameters and update the parameters in the cross-coupling compensator and current controller. The resulting controller maintains the typical fast response of the predictive current control and a better adaptability to the parameters variation. The simulation results show the validity of the analytic approach and the efficiency of the proposed method.

Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2014/397538 The tire mechanical characteristics under combined cornering and braking/driving situations have significant effects on vehicle directional controls. The objective of this paper is to present an analytical tire model with flexible carcass for combined slip situations, which can describe tire behavior well and can also be used for studying vehicle dynamics. The tire forces and moments come mainly from the shear stress and sliding friction at the tread-road interface. In order to describe complicated tire characteristics and tire-road friction, some key factors are considered in this model: arbitrary pressure distribution; translational, bending, and twisting compliance of the carcass; dynamic friction coefficient; anisotropic stiffness properties. The analytical tire model can describe tire forces and moments accurately under combined slip conditions. Some important properties induced by flexible carcass can also be reflected. The structural parameters of a tire can be identified from tire measurements and the computational results using the analytical model show good agreement with test data. © 2014 Nan Xu et al.

This study is to describe the transient force and moment characteristics of tyres involving large lateral slip, longitudinal slip, turn-slip and camber, and to develop a dynamic tyre model applicable to vehicle dynamic simulation and control for extreme operating conditions. Based on the steady state USES tire model [4,6], the effective slip ratios and quasi-steady concept are introduced to represent the non-linear dynamic tire properties in large slip cases. A high-order non-steady tyre model is presented. Special attention has been paid on the relationship between turn-slip and camber. Various kinds of experiments are performed to verify the tire model.

The response simulation is studied and the handling safety is evaluated using finer integration method for driver-vehicle closed-loop system with stationary random road input. This algorithm is not only precise, but can also shorten the evaluation period of handling safety and reduce the tremendous cost for real vehicle testing. The response simulation and the vehicle handling safety evaluation are also studied for the closed-loop system with evolutionary random road input. The study can more truly simulate vehicle handling quality for including the varying of vehicle velocity with time.

This paper proposes the integrated controller of the yaw and rollover stability controls based on the prediction model. A nonlinear 3-DoF vehicle model with a piecewise linearization tire model is built up as the rollover predictive model, and its accuracy is verified by vehicle tests. A yaw stability controller and a rollover stability controller are proposed, respectively. Then coordinated control strategy is investigated for the integration of vehicle yaw and roll stability controls. The additional yaw torque and braking torque of each wheel are calculated. The unified command of valves is sent combined with ABS control algorithm. Virtual tests in CarSim are carried out, including slalom condition and double-lane change condition. Results indicate that the coordinated control algorithm improves vehicle yaw and roll stability effectively.

Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/986584 Open access The road surface roughness is the main source of kinematic excitation of a moving vehicle, which has an important influence on vehicle performance. In recent decades, random road models have been widely studied, and a four-wheel random road time domain model is usually generated based on the correlation of the four-wheel input, in which a coherence function is used to describe the coherence of the road input between the left and right wheels usually. However, during our research, there are some conditions that show that the road PSD (power spectral density) of one wheel is smaller than the other one on the same axle. Actually, it is caused by the uncorrelation between the left- and right-wheel road surface roughness. Hence, a frequency compensation algorithm is proposed to correct the deviation of the PSD of the road input between two wheels on the same axle, and it is installed in a 7-DOF vehicle dynamic study. The simulation result demonstrates the applicability of the proposed algorithm such that two-wheel road input deviation compensation has an important influence on vehicle performances, and it can be used for a control system installed in the vehicle to compensate road roughness for damper tuning in the future.

Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http:/dx.doi.org/10.1155/2013/283528 Open Access Vehicle dynamics are directly dependent on tire-road contact forces and torques which are themselves dependent on the wheels' load and tire-road friction characteristics. An acquisition of the road disturbance property is essential for the enhancement of vehicle suspension control systems. This paper focuses on designing an adaptive real-time road profile estimation observer considering load variation via vehicle vertical dynamics. Firstly, a road profile estimator based on a linear Kalman filter is proposed, which has great advantages on vehicle online control. Secondly, to minimize the estimation errors, an online identification system based on the Recursive Least-Squares Estimation is applied to estimate sprung mass, which is used to refresh the system matrix of the adaptive observer to improve the road estimation efficiency. Last, for mining road category from the estimated various road profile sequencse, a road categorizer considering road frequency and amplitude simultaneously is approached and its efficiency is validated via numerical simulations, in which the road condition is categorized into six special ranges, and this road detection strategy can provide the suspension control system with a better compromise for the vehicle ride comfort, handling, and safety performance.

SUMMARY Theoretically a unified tire model with non-isotropy of friction is presented as a foundation for studying the key features of a reasonable expression of tire shear force and alignment torque under combined slip conditions. The effects of longitudinal force and pressure distributionon tire cornering stiffness are analyzed. A unified semi-empirical tire model with high accuracy and convenience in vehicle dynamics simulation is proposed. Some experimental validations are shown.

This paper sets the hydraulic engine mount (HEM) of a car as its research object and established the strong fluid–solid interaction finite element model for its property analysis by adopting the INTESIM strong fluid–solid finite element method. A stimulation analysis of the model’s static and translation dynamic stiffness characteristics was conducted,compared with the experimental result and the effectiveness of the simulation research findings was verified. The research demonstrates that the translation dynamic characteristics of the HEM can be effectively simulated by the INTESIM strong fluid–solid finite element method; on the basis of which, a preliminary discussion on its torsion dynamic stiffness characteristics was carried out also.

In this paper, a simulation model of flexible virtual proving ground (VPG) for a car was created in view of the shortcomings of long test cycle and high cost of traditional enhancement test for suspension durability at car development stage, with a variety of durability enhanced roads in the Nong’an Proving Ground as inputs. It solved a string of key technological problems regarding VPG applications. In addition, the time-history dynamic stress response of a car suspension system was analyzed, compared with the real vehicle durability test results obtained under the same conditions. The results of the simulation test and the real test are basically identical in terms of the trend of time and frequency domains. Furthermore, it demonstrates the effectiveness of the simulated suspension system’s dynamic stress response for the flexible VPG technology, and realized the effective prediction for the suspension system durability in the development process.

The Electronic Stability Control (ESC) system is analyzed to provide available information for side-slip angle estimation. According to analysis of research on side-slip angle estimation, a sliding mode observer of side-slip angle is designed based on ESC sensor system and seven-freedom vehicle model, the stability of observer is also discussed. The verification of sliding mode observer is carried out under veDYNA vehicle dynamic simulation environment, the result indicates that the side-slip angle estimation of sliding mode observer holds certain accuracy and meets the requirement of ESC logic.

In this paper, a mathematical model of electric power steering (EPS) system is set up through the dynamic analysis of EPS system. H infinity controller is designed using robust control theory to aim at the disturbance and sensor noise which exist in the system. A simulation using MATALAB/SIMULINK is performed. The results show that the electric power steering system with H infinity controller has a good performance.

Firstly, a hydraulic model was carried out based on the structure of a certain hydro-pneumatic spring. Furthermore, with the distortion being involved, the dynamics model with the consideration of the distortion was built in Matlab/Simulink. Finally, the validity and accuracy of the model was evaluated through the comparison between the simulation output and the experiment data. The result shows this dynamics model has very high accuracy and could precisely express the characteristics of the hydro-pneumatic spring. It can also offer a reference and basis for the hydro-pneumatic spring analysis.

Based on the Preview-Follower theory and PID control of stability, an efficient driver model for nonlinear motorcycle is established. The driver's correction parameters are derived directly from the theory. The procedure of parameters' achievement is introduced. A motorcycle multi-body model is built with Adams/view for closed-loop simulation. The results show that the driver model can effectively follow the target road.

Based on the UniTire model in low frequency and the characters of tire vibration in high frequency, an in-plane dynamic tire model is built, which is appropriate for studying on the advanced chassis control. The theory and procedure of modeling are introduced. The parameters of the model are received from the identification of test data. The model is validated by tire dynamic test data, which is got by the tire passing through the classic uneven road at various speeds.

Suspension modeling has great influence on the accuracy of whole vehicle simulation. In this paper, a new method is presented to build the suspension model based on its K&C characteristics. And a 14DOF vehicle model is developed to validate this method. The simulation results are compared with that got from commercial software CarSim, and have showed good agreement.

Tire force and moment properties are the function of rolling distance and always show non-steady state behaviors with varying slip angle and vertical load. In this paper, considering flexible carcass, a tire side slip rolling model is presented and some simulations are demonstrated. Such model can serve as benchmark for developing pragmatic semi-physical model and analysis tool for understanding tire stress phenomena in contact patch.

Empirical tire models provide a reasonably good representation of experimental data for tire lateral force and aligning moment properties. However, empirical models would become quite complicated while increasing input dimensions without theoretical support. This paper deals with a theoretical model taking flexible carcass lateral deformation characteristics into account. Three tire carcass structure parameters are presented to describe flexible carcass deformation characteristics during tire rolling, and based on these parameters tire non-steady state cornering behaviors are investigated.

This paper discusses relationships and differences between a tire under braking and driving conditions, and the processes utilized to predict the tire's driving force characteristics. In the current paper, dynamic normal load distribution and dynamic friction are included into the analytical tire model which is validated by comparing simulated results to experimental data. The physical parameters of tire and friction are extracted from experimental data using UniTire. Finally the driving force characteristics are predicted and compared to those obtained from tire test equipment.

In this paper, a comprehensive evaluation method for vehicle handling based on the driver’s subjective evaluation to different vehicle configurations has been studied by using development driving simulator tests. An objective evaluation index is developed which consists of several individual evaluation indices affecting vehicle handling. A series of weighting factors corresponding to individual evaluation indexes are found by using the Genetic Algorithm to reach the best agreement between the objective evaluation and the average of subjective evaluation of the drivers. Simulator test scheme has been designed and carried out with 14 vehicle configurations, and subjective evaluation has been made for easy handling of vehicle by a group of drivers. A driver/vehicle close-loop system model has been established which can predict the vehicle motion of handling and stability. Vehicle design parameters and control parameters of its control system have been optimized by using the driver/vehicle close-loop system model and objective evaluation index.Copyright © 2005 by ASME

In this paper, on the basis of the extant semi-empirical tire models of non-steady state with pure yaw angle input and pure side slip angle input, two empirical tire models of non-steady state side slip properties are established, one is pure yaw angle input, the other is pure side slip angle input, and both of them have been verified by test data. These two models can be used to approximately express tire force within low frequency. They have their own advantages, and make up for the disadvantages of existing tire models. They provide more choice for the simulation of vehicle dynamics.

This paper gives an outline of the JUT-ADSL driving simulator. Some modeling problems of the driving simulator, such as simulation delay, tire model, expression of steering hysteresis, rolling resistance and braking torque are discussed. Some examples of application of the driving simulator for research and development (R&D) activities, such as virtual design and testing for vehicle handling, studies of active vehicle control, the study of objective evaluation technology and driver behavior and modeling are described.

The behavior of driver course decision making is analyzed with the theory of system fuzzy decision making, and some factors that influence this behavior are studied also. Based on these, a fuzzy decision making model of driver dynamically determining vehicle preview course is given. This model can simulate the driver's control behavior of deciding the vehicle preview course in the process of driver handling the vehicle, based on the feasible region of front road. Taking advantage of fuzzy decision making theory's character, the model can describe many decision criteria such as driving safety, driving handiness and driving legality. The simulation results show that the model can be directly applied into the simulation of driver-vehicle-road closed-loop system and the research of intelligent vehicle. For the covering abstract see ITRD E108169.