• 동력기계공학회지
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• 제19권3호
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• pp.42-47
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• 2015

This paper studies on the design of a servo controller for an antilock brake system(ABS) based on the car tire model. First, a nonlinear differential equation of the car tire is constructed and its linearization model is obtained by Taylor's series. Second, a servo controller based on the mathematical model is analytically designed to obtain the maximum brake force, where the tire velocity and the slip ratio of car tire are respectively controlled to the given command values. Third, it is theoretically shown that the proposed control algorithm has good usefulness in ABS.

• 제어로봇시스템학회논문지
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• 제4권6호
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• pp.722-728
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• 1998

In this paper real-time estimation methods for identifying the tire-road friction coefficient are presented. Taking advantage of the Magic Formula Tire Model, the similarity technique and the specific model for the vehicle dynamics, a reduced order observer/filtered-regressor-based method is proposed. The Proposed method is evaluated on simulations of a full-vehicle model with an eight state nonlinear vehicle/transmission model and nonlinear suspension model. It has been shown through simulations that it is possible to estimate the tire-road friction from measurements of engine rpm, transmission output speed and wheel speeds using the proposed identification method. The proposed method can be used as a useful option as a part of vehicle collision warning/avoidance systems and will be useful in the implementation of a warning algorithm since the tire-road friction can be estimated only using RPM sensors.

• 한국자동차공학회논문집
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• 제8권4호
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• pp.169-176
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• 2000

Longitudinal and lateral forces acting on tires are known to be closely related to the tract-ability braking characteristics handling stability and maneuverability of ground vehicles. In thie paper in order to develop tire force monitoring systems a monitoring model is proposed utilizing not only the vehicle dynamics but also the roll motion. Based on the monitoring model three monitoring systems are developed to estimate the tire force acting on each tire. Two monitoring systems are designed utilizing the conventional estimation techniques such as SMO(Sliding Mode Observer) and EKF(Extended Kalman Filter). An additional monitoring system is designed based on a new SKFMEC(Scaled Kalman Filter with Model Error Compensator) technique which is developed to improve the performance of EKF method. Tire force estimation performance of the three monitoring systems is compared in the Matlab simulations where true tire force data is generated from a 14 DOF vehicle model with the combined-slip Magic Formula tire model. The built in our Lab. simulation results show that the SKFMEC method gives the best performance when the driving and road conditions are perturbed.

• International Journal of Precision Engineering and Manufacturing
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• 제9권3호
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• pp.75-78
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• 2008

Tire molds are manufactured by aluminum casting, direct five-axis machining, and electric discharging machining. Master models made of chemical wood are necessary if aluminum casting is used. They are designed with a three-dimensional computer-aided design system and milled by a five-axis machine. In this paper, a method for generating and machining a tire surface model is proposed and demonstrated. The groove surfaces, which are the main feature of the tire model, are created using a parametric design concept. An automatically programmed tool-like descriptive language is presented to implement the parametric design. Various groove geometries can be created by changing variables. For convenience, groove surfaces and raw cutter location (CL) data are generated in two-dimensional drawing space. The CL data are mapped to the tread surface to obtain five-axis CL data to machine the master model. The proposed method was tested by actual milling using the five-axis control machine. The results demonstrate that the method is useful for manufacturing a tire mold.

• 한국자동차공학회논문집
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• 제24권5호
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• pp.581-587
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• 2016

Braking is a basic and an important safety feature for all vehicles, and the final braking performance of a vehicle is determined by the vehicle's ABS performance and tire performance. However, the combination of excellent ABS and tires will not always ensure good braking performance. This is due to the fact that tire performance has non-linearity and uncertainty in predicting the repeated increase and decrease of wheel slip when activating the ABS, thus increasing the uncertainty of tire performance prediction. Furthermore, existing studies predicted braking performance after using an ABS that used a wheel slip control as a controller, which was different from an actual vehicle's ABS that controlled angular acceleration, therefore causing a decrease in the prediction accuracy of the braking performance. This paper reverse-designed the ABS that controlled angular acceleration based on the information on brake pressure, etc., which were obtained from vehicle tests, and established a braking performance prediction analysis model by combining a multi-body dynamics(MBD) vehicle model and a magic formula(MF) tire model. The established analysis model was verified after comparing it with the results of the braking tests of an actual vehicle. Using this analysis model, this study analyzed the braking effect by vehicle factor, and finally designed a tire that had optimized braking performance. As a result of this study, it was possible to design the MF tire model whose braking performance improved by 9.2 %.

• 한국자동차공학회논문집
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• 제24권3호
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• pp.310-318
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• 2016

The demands for vehicle safety systems such as ABS and ESC have been increased. Accurate vehicle state estimation is required to realized the abovementioned systems and tire-friction coefficient is crucial information. Estimation of lateral tire-road friction coefficient using pneumatic trail information is mainly dealt in this paper. Pneumatic trail shows unique characteristics according to the wheel side slip angle and these property is highly sensitive to vehicle lateral motion. The proposed algorithm minimizes the use of conventional tire models such as magic formula, brushed tire model and Dugoff tire model. The pure side slip maneuver, which means no longitudinal dynamics, is assumed to achieve the ultimate goal of this paper. A simulation verification using Carsim and Simulink is performed and the results show the feasibility of the proposed algorithms.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1371-1375
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• 2005

The paper has analyzed the influence of tire design variable on the tire Force and Moment (F&M) characteristics, especially by the belt angle, the Plysteer Residual Aligning Torque (PRAT) which is considered as one of the causing factors for the vehicle pull. To validate the tire FE model, the tire stiffness and the PRAT which can be derived from the simulation data have been compared with the experimental data of test machine. In addition to PRAT characteristic, the tire stiffness and cornering characteristics due to the belt angle have been investigated. The effects of drum's curvature on the PRAT have been also investigated using the tire FE model and the usefulness of the current drum type F&M test machine can be confirmed.

• 한국자동차공학회논문집
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• 제14권2호
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• pp.76-83
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• 2006

Each tire has a critical speed at which a standing wave phenomenon occurs along the circumferential direction. If the standing waves are formed, the tire temperature is rapidly increased and it leads to tire failure eventually. As the formation of the standing waves is closely related to the tire stiffness, the effect of the tread pattern needs to be studied numerically. The standing wave phenomenon of a tire model with tread pattern is predicted by an explicit finite element method. The critical speed of the tire with tread pattern is in a good agreement with the experiment and is $15{\sim}20\;km/h$ lower than that of the tire without tread pattern. The effects of the inflation pressure and the vertical load on the critical speed are also investigated by using the tire model with tread pattern.

• Agricultural and Biosystems Engineering
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• 제1권1호
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• pp.1-6
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• 2000

Using the modified DEM (Distinct Element Model), which we proposed, the effect of cross section of tire lug on the tire performance was simulated. Though the DEM has an advantage over the FEM when it is applied to simulate the behavior of discrete assembly of particles such as soil, there was still a problem in the case of conventional DEM, that the simulated movement of particles was too free. We constructed a new mechanical model (modified DEM) which can take account of the effect of adhesion between particles. It is shown that the soil deformation is simulated by the modified DEM better than the conventional DEM. Comparing the simulated soil reaction to the tire lug with the experimental results, the adequate DEM parameters were found. It is also indicated possible to find the effect of lug cross section shape on the tractive performance of tire by the DEM simulation.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.539-544
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• 2004

This paper discusses the measurement of tire driving performance for 2 types of tire model. Tire is almost composed of rubber, and this is related with the bearing capacity of tire due to the external force. In this study, an explicit time integration method has been used to simulate steady state rolling along a straight path and over a cleat. And analysis for tire dynamic response rolling over a cleat is importnat to study automobile NVH properties. Besides, the evaluation of contact shear force is perfomed for steady state rolling and braking state. The results show that there are noticeable differences between 205/60R15 and 225/60R15 tire model.