Tire Test Data Research Articles

Trajectory Planning and Tracking for Four-Wheel Independent Drive Intelligent Vehicle Based on Model Predictive Control

<div class="section abstract"><div class="htmlview paragraph">This paper proposes a dynamic obstacle avoidance system to help autonomous vehicles drive on high-speed structured roads. The system is mainly composed of trajectory planning and tracking controllers. The potential field (PF) model is introduced to establish a three-dimensional potential field for structured roads and obstacle vehicles. The trajectory planning problem that considers the vehicle’s and tires’ dynamics constraints is transformed into an optimization problem with muti-constraints by combining the model predictive control (MPC) algorithms. The trajectory tracking controller used in this paper is based on the 7 degrees of freedom (DOF) vehicle model and the UniTire tire model, which was discussed in detail in previous work [<span class="xref">25</span>, <span class="xref">26</span>]. The controller maintains good trajectory tracking performance even under extreme driving conditions, such as roads with poor adhesion conditions, where the car’s tires enter the nonlinear region easily. The innovation of this paper lies in introducing a high-fidelity vehicle model and a muti-conditions UniTire tire model with high precision obtained after parameter identification through tire test data. In addition, the nonlinear relationship between tire lateral force and slip angle is expressed as a linear function. This method updates the equivalent cornering stiffness in the linear function by solving the slope of the secant of the tire cornering characteristic curve at the current moment online, which solves the problem of high computational complexity caused by applying complex tire models in the control system. The co-simulation results of Simulink and CarSim show that the designed system has good dynamic obstacle avoidance and driving stability performance under driving conditions with high speed and poor road adhesion.</div></div>

Application of Fatigue Simulation Analysis Based on CDTire

In order to verify the fatigue-durability performance of chassis components, the simulation and analysis process is established in this paper based on CDTire model. High-accuracy tire model is constructed by CDTire modeling software according to the tire test data. The multi-body dynamics simulation is completed by combining the CDTire model with the vehicle model. The load of chassis components is extracted and imported into fatigue software. The swing arm is taken as an example for calculation. This analysis process can guide the analysis of chassis components and shorten the development cycle.

Multi-sensor Fusion Road Friction Coefficient Estimation During Steering with Lyapunov Method.

The road friction coefficient is a key parameter for autonomous vehicles and vehicle dynamic control. With the development of autonomous vehicles, increasingly, more environmental perception sensors are being installed on vehicles, which means that more information can be used to estimate the road friction coefficient. In this paper, a nonlinear observer aided by vehicle lateral displacement information for estimating the road friction coefficient is proposed. First, the tire brush model is modified to describe the tire characteristics more precisely in high friction conditions using tire test data. Then, on the basis of vehicle dynamics and a kinematic model, a nonlinear observer is designed, and the self-aligning torque of the wheel, lateral acceleration, and vehicle lateral displacement are used to estimate the road friction coefficient during steering. Finally, slalom tests and DLC (Double Line Change) tests in high friction conditions are conducted to verify the proposed estimation algorithm. Test results showed that the proposed method performs well during steering and the estimated road friction coefficient converges to the reference value rapidly.

A brush-based thermo-physical tyre model and its effectiveness in handling simulation of a Formula SAE vehicle

The ability to model tyre dynamics precisely is often one of the most critical elements for realistic vehicle dynamics control and handling investigations. The industry-standard empirical models are able to predict the important tyre forces accurately over a short range of vehicle operating conditions, which is often restricted to the operating conditions experienced during the tyre testing process. In this paper, an alternative and practical method to model Formula SAE tyres has been proposed and studied in a series of possible running scenarios. A simple, analytically solved brush-type tyre model is considered for the physical part with the introduction of a novel approach for defining the contact length formulation that incorporates the influence of inflation pressure, camber angle and velocity, while a set of ordinary differential equations are employed to predict the thermal behaviour of the tyre model, which are mostly based on an already-existing method that has not been experimentally validated before. The resulting tyre models provide realistic and informative behaviour of the tyre, which has the ability to consider the majority of the typical operating conditions experienced on a Formula SAE vehicle. The performance of the proposed tyre models is compared against experimental tyre test data, which shows good agreement and indicates that the tyre models have the ability to give realistic predictions of the tyre forces and thermal behaviour in the case of thermal tyre model. Furthermore, the temperature-dependent tyre model has been incorporated into a two-track model of Oxford Brookes Racing’s Formula SAE vehicle to study the effectiveness of the tyre model during transient handling simulation. The resulting simulations suggest that the proposed tyre model has the ability to represent realistic operating conditions of tyres, and also that tyre temperatures influence the vehicle dynamic behaviour significantly during on-limit scenarios.

Simulation Analysis of Tire Dynamic Model

The tire dynamics simulation was done for the different speeds on the dry and wet roads with Magic Formula tire model. The coefficients of Magic Formula tire model under different conditions were obtained by means of the tire test data based on the nonlinear least squares method. The Magic Formula has a good ability to fit the test data for the longitudinal, lateral force and align moment. The tire dynamics simulation results show that at 30mph the wet tire peak longitudinal and lateral forces are only slightly less than the dry peak forces. The wet tire peak longitudinal and lateral forces decreases as the tire speed increases. This shows that the speed has a larger impact on the tire force. The align moment is relatively small. So it can be ignored in the vehicle dynamics analysis.

Improving Genetic Algorithm Based Parameter Optimizing LSSVM Model for Tyre Regression

According to the requirement of vehicle dynamics' accurate simulation and control, the paper studies the tyre regression algorithm based on the tyre bench test data. Due to the tyre test's characters of few data and big discreteness, the method of least squares support vector regression (LSSVM), which has the superiority of structural risk minimization, was selected to find the nonlinear mapping between input and output variables of tyre test data. Removing data gross error and improving the sparsification measures were taken to increase the calculation real time of standard LSSVM algorithm. An adaptive genetic algorithm (AGA) with global searching ability was chosen to determine the kernel function and regularization parameters of LSSVM. Test data set’s regression root mean square error (RMSE) was taken as the fitness function of AGA. Finally, the tyre test data under steady state sideslip condition was provided to simulate and verify the effectiveness of tyre regression algorithm, according to the precision and real time requirements of vehicle dynamic simulation and control.

A low parameter tyre model for aircraft ground dynamic simulation

The work presented in this paper describes a new low parameter mathematical model representing the force and moment components generated in an aircraft tyre for use in the computer simulation of takeoff, landing and taxiing manoeuvres of an aircraft. As such the problems addressed fall in the area of ground vehicle dynamics and the modelling of the tyre presents similar challenges to those involved in modelling automotive tyres, albeit on a much larger scale in terms of the size and the loads on the tyre.The model has been implemented in the Matlab/Simulink environment and designed to run initially with aircraft models defined by the industry standard multi-body systems program MSC.ADAMSTM.An overview is provided of current automotive and aircraft tyre models along with a critique of the application and capabilities of these existing models for aircraft simulation. The need for a model which can be used to fit the limited range of data available for aircraft tyres, compared with automotive tyres, is also discussed.The proposed low parameter tyre model (LPTM) uses a small set of model parameters that can be obtained without recourse to special software and can be easily manipulated to fit the model to available tyre test data. The model has been exercised and compared with two existing tyre models, using a multi-body computer model of a tyre test machine and has been shown to produce improved predictions of the important forces and moments generated in a tyre contact patch when validated against test data. The evaluation at this stage is related to the tyre characteristics needed to simulate vehicle braking and cornering manoeuvres and the validation is against available test data for the lateral force and aligning moment arising due to slip angle.

A coevolutionary algorithm for tyre model parameters identification

The problem of tyre model coefficients identification using minimum test data is studied in this work. To obtain these tyre model parameters, an intense research effort by the automotive community has been made and there are different methods to fit the values of these parameters. This problem is addressed in this work through a coevolutionary algorithm that interactively searches the optimum tyre model parameters and new test data in disagreement with the tyre model. The algorithm is composed of two stages: the estimation phase, which finds out the tyre model parameters which can predict actual tyre test data, and the exploration phase, which finds out new test data which have the most disagreement with the response of the current model. The feasibility of the methodology is demonstrated comparing the obtained results with other known techniques.

Intermediate tyre model for vehicle handling simulation

The work presented in this article describes a new mathematical model of the force and moment components generated in a tyre to road surface contact patch. The model has been implemented with the industry standard multi-body systems program MSC.ADAMS™ and is intended for use in computer simulations of proving ground-test manoeuvres used to evaluate vehicle handling performance. The proposed model uses a small set of model parameters that can be obtained without recourse to special software and can be easily manipulated to fit the model to tyre test data. The model has been exercised and compared with two existing tyre models using a multibody computer model of a tyre test machine and has been shown to produce reliable predictions of the important forces and moments generated in a tyre contact patch. The tyre test data and model parameters used are provided here. The evaluation at this stage is related to the tyre characteristics needed to simulate vehicle braking and cornering manoeuvres.

Modelling of tire overturning moment and loaded radius

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 [Pacejka, H.B., 2002, Tyre and Vehicle Dynamics. Butterworth-Heinemann, an imprint of Elsevier Science, ISBN 0-7506-5141-5]. However, there are few studies for the tire overturning moment (TOM), especially under large slip angle and camber angle. For the simulation of vehicle rollover, the expression accuracy of TOM is rather important. In addition, the difference of the loaded radius of left and right tires yields tire roll angle and that also affects vehicle roll behavior. In this paper, the modeling of TOM and loaded radius are presented first, and then the modeling results are compared with tire test data.

A TIRE MODEL FOR USE WITH VEHICLE DYNAMICS SIMULATIONS ON PAVEMENT AND OFF-ROAD SURFACES

ABSTRACT STIREMOD is an expanded version of an earlier vehicle simulation tire model designed for the full range of operating conditions (slip, camber, normal load) on both paved and off-road surfaces. Within a vehicle dynamics simulation tire model parameter sets can be changed dynamically to reflect the local operating condition of each tire. This paper summarizes the general tire model structure, data sources, parameter identification and model fits to tire test data.

Road Surface Correction o f Tire Test Data

SUMMARY Most tire data used for vehicle simulations is measured on laboratory test facilities. An investigation showed that the frictional properties of these laboratory machines can be quite different from actual road conditions. This paper describes a method to correct laboratory tire test data to be more like road data in order to achieve a higher degree of correlation between instrumented test- and simulation results.

A TIRE MODEL FOR USE WITH VEHICLE DYNAMICS SIMULATIONS ON PAVEMENT AND OFF-ROAD SURFACES

ABSTRACT STIREMOD is an expanded version of an earlier vehicle simulation tire model designed for the full range of operating conditions (slip, camber, normal load) on both paved and off-road surfaces. Within a vehicle dynamics simulation tire model parameter sets can be changed dynamically to reflect the local operating condition of each tire. This paper summarizes the general tire model structure, data sources, parameter identification and model fits to tire test data.

Characteristics of Tire Force and Moment Data

Abstract Tire force and moment data are fundamental inputs to vehicle handling simulations. Tire asymetries and tire and test variability must be considered in force and moment testing. This article provides a discussion of asymmetries in tire force and moment behavior and of variation in their data. The asymmetry discussion is thoroughly general. The variability discussion is philosophically general, but the data are specific to the test specifications and tests used. Variability data are presented for the range from −14 to +14 degrees slip angle. The data and concepts concerning tire asymmetries and test data variability presented are especially important now because work to produce up-to-date force and moment testing standards is beginning under the auspices of the Society of Automotive Engineers (SAE).

Pneumatic tire model for aircraft simulation

The development of a tire model for the prediction of vertical and drag loads in response to large discrete surface obstacles shorter than the tire footprint length is presented. The tire is modeled as a toroidal membrane with the objective of characterizin g the enveloping properties of the tire. An explicit set of equations is used to calculate the tire footprint in contact with a user specified surface profile, the tire volume, the pneumatic pressure, and the resultant vertical and drag loads at the wheel axle. Tire carcass and bottoming loads are also predicted. The model is designed to be computationally efficient for use with aircraft digital taxi simulations. Model predictions are compared with tire test data for low-speed fixed axle excursions over short rectangular bumps and dips. Excellent quantitative correlation is demonstrated.

A Tire Runway Interface Friction Prediction Model Concept

A thorough literature survey was conducted to establish the range of aircraft tires in use, types of runway surfaces in use, and a list of factors affecting tire-runway interface phenomenon. Both commercial and military aircraft tires and runways were studied. Subsequently, a prediction model has been developed that correlates with existing tire test data to within ±5%. The model consists of a prediction equation expressing the relationships between seven dimensionless groups (pi .terms) needed to define the tire-runway interface friction. Due to lack of availability of uniform test data, a tire test program has been recommended to validate the said model.