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Experimental Investigation of the Influence of Tire Design Parameters on Anti-lock Braking System (ABS) Performance
Abstract and Figures
Anti-lock Braking System (ABS) is a critical safety component and its performance is crucial for every vehicle manufacturer. The tire plays an important role during an ABS braking maneuver as it is the component that connects the vehicle to the ground and is responsible for generating braking force. The steady-state and transient properties of the tire affect the operation of the vehicle's ABS system and consequently affects its performance/ operational efficiency. The main objective of this study is to investigate how tire design changes influence its interaction with the ABS and its eventual effect on stopping distance. This was conducted through an experimental study where tires were built with three levels of variation in carcass stiffness, tread stiffness and tread compound. Following this, ABS braking maneuvers were performed on two instrumented vehicles including a mid-tier sedan and a high-performance sports car. The steady-state properties of the tire were calculated from experimental data measured both on the vehicle and from the braking skid trailer and thereafter the sensitivity of a given ABS system to such changes in tire properties were analyzed. Lastly, the feasibility of adding intelligence in ABS controllers is investigated through an on-line tire identification routine to determine the tire slip set point value for the ABS controller to maximize the tire braking force.
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... Reduction of the stopping distance often comes as a consequence, since the ABS controller (if correctly tuned) makes the tire work in the neighborhood of the peak of the l-slip curve [1][2][3][4]. Figure 1 represents the working principle of the acceleration-based ABS control cycle provided by Bosch and others [1][2][3][4][5][6][7][8] (The detailed description of the ABS control algorithm is omitted in the present paper. The reader is referred to the literature for details [1][2][3][4][5][6][7][8]). The ABS control algorithm modulates the braking pressure (as shown in the lower part of Fig. 1) at each wheel mainly based on its peripheral acceleration (central part of Fig. 1) and secondarily its slip ratio (upper part of Fig. 1). ...
... Figure 1 represents the working principle of the acceleration-based ABS control cycle provided by Bosch and others [1][2][3][4][5][6][7][8] (The detailed description of the ABS control algorithm is omitted in the present paper. The reader is referred to the literature for details [1][2][3][4][5][6][7][8]). The ABS control algorithm modulates the braking pressure (as shown in the lower part of Fig. 1) at each wheel mainly based on its peripheral acceleration (central part of Fig. 1) and secondarily its slip ratio (upper part of Fig. 1). ...
... The aim of the present paper is to evaluate the effect of main tire parameters on the stopping distance in the frame of an ABS algorithm. In this regard, the following tire parameters (see Appendix A) are referred in the technical literature as the most relevant [5][6][7][8][9][10]: ...
The antilock braking system (ABS) is an active control system, which prevents the wheels from locking-up during severe braking. The ABS control cycle rapidly modulates braking pressure at each wheel mainly based on tire peripheral acceleration. Significant wheel speed oscillations and consequent fast variations of tire longitudinal slip are a consequence, which, in turn, produce a corresponding variation of tire longitudinal force according to the ABS control cycle. Clearly, tire characteristics, namely, tire peak friction (regulating maximum vehicle deceleration), longitudinal stiffness, optimal slip ratio, curvature factor (regulating the position of the peak of µ-slip curve and the subsequent drop), and relaxation length (accounting for tire dynamic response) may significantly influence ABS performance. The aim of the present paper is to evaluate the effect of the main tire parameters on ABS performance. This task is, however, very challenging, since tire characteristics are intrinsically related, and the analysis involves interaction between tires, vehicle, and ABS control logic. A methodology based on the hardware-in-the-loop (HiL) technique is used. This approach was selected to overcome limitations of numerical simulations or difficulties related to the execution of onroad experimental tests (repeatability, costs, etc.). The developed HiL test bench includes all the physical elements of the braking system of a vehicle (comprising the ABS control unit) and a 14 degrees of freedom (dofs) vehicle model, which are synchronized by a real-time board. With the developed HiL test bench, a sensitivity analysis was carried out to assess the influence of tire peak friction, longitudinal stiffness, and relaxation length on ABS performance, evaluated in terms of braking distance, mean longitudinal acceleration, and energy distribution.
... a. as a function of cap compound and tread depth) and the contact patch length (as a function of load and inflation pressure), the carcass stiffness is mainly a function of the tire construction. The relative contri- bution of each component to the total longitudinal slip stiff- ness depends on the tire construction [25,26]. Since the infla- tion pressure has a counteracting effect on these two compo- nents, it can be expected that the slip stiffness first increases when increasing the tire inflation pressure (at low inflation pressures), and at higher inflation pressure decreases with increasing inflation pressure [27]. ...
... Friction Coefficient at High Slip Several publications (see [25,26,29]) point out that the shape (at peak friction) of the tire characteristic curve and the drop after the peak influence the ABS performance, respectively the stopping distance, of a vehicle. In this study the ratio between the maximum friction force coefficient and the friction force coefficient at 30% brake slip was found appropriate to describe the drop after the peak of the tire characteristic. ...
Since the tire inflation pressure has a significant influence on safety, comfort and environmental behavior of a vehicle, the choice of the optimal inflation pressure is always a conflict of aims. The development of a highly dynamic Tire Pressure Control System (TPCS) can reduce the conflict of minimal rolling resistance and maximal traction. To study the influence of the tire inflation pressure on longitudinal tire characteristics under laboratory conditions, an experimental sensitivity analysis is performed using a multivalent usable Corner Module Test Rig (CMTR) developed by the Automotive Engineering Group at Technische Universität Ilmenau. The test rig is designed to analyze suspension system and tire characteristics on a roller of the recently installed 4 chassis roller dynamometer. Camber angle, toe angle and wheel load can be adjusted continuously. In addition, it is possible to control the temperature of the test environment between −20 °C and +45 °C. The results of the experimental study that covers a wide range of different wheel loads and inflation pressures for three different tire variations show a significant influence of the inflation pressure on longitudinal tire characteristics as slip stiffness or maximum traction force. To simulate the influence of a TCPS on vehicle dynamics with a numerical simulation tool, it is essential to describe the influence of the inflation pressure on tire characteristics correctly with a tire model. Consequently, the well-known semi-empirical Magic Formula tire model adapted from Pacejka is extended for large inflation pressure changes. The parameters of the tire model are identified with a method of least squares which is implemented in an automatic MATLAB analysis tool. A comparison of the standard and respectively the enhanced tire model show an obvious improvement of the model accuracy.
... The sliding mode controller provides robust performance, although instability of the road coefficient [54]. The producing braking forces rely on tire surface contact [55]. The Takagi-Sugeno hierarchical fuzzy-neural mode can be used to decrease the processing time of the controller as well as the control rules [56]. ...
Anti-lock braking systems are widely used in modern vehicles and provide safe driving for many different road conditions. Tire skidding occurs unexpectedly as a result of non-linearity in the system. The system behavior can be modelled and simulated using simulation software, which would help to visualize the system behavior. It would lead to obtaining optimum brake performance as well as safe driving. Modelling and simulation methods that can be used with every component of the system are presented. A variety of simulation software has been discussed.
... Xia et al. [35] present the effect of tire cornering stiffness pa ra meters on veh icle ha nd l i ng per for ma nce. Sivaramakrishnan et al. [36] describe how tire design affects ABS and its stopping distance. In their work, they tested tires with different treads and carcass stiffnesses. ...
Understanding the behavior of the contact patch can help to identify various parameters like pressure distribution, contact patch dimension, and tire forces, which play a crucial role in vehicle handling performance. In current work, the Stereo-Digital Image Correlation (DIC) application in measuring the contact patch dimension in the static and dynamic condition of standing or rolling tire is developed. Under the static measurement of a standing tire, Stereo DIC is used to plot the three-dimensional (3D) view of the contact patch aiming to extract contact patch dimension information. Under the dynamic condition of a rolling tire, tire carcass deflection in the radial direction can help to obtain contact patch dimensions using curvature information as presented. Also, a novel method to measure the contact patch dimension is proposed. The technique uses a white strip pasted onto the drum of the tire test rig available. A pair of action cameras is applied on the tire test rig to capture videos of tire rolling behavior over the drum. Captured videos are then processed in MATLAB to track the position of the white strip pasted on the drum using color intensity information. Based on the video images, the contact patch length (CPL) is calculated in combination with a scale factor. The lateral deformation of a tire plays a vital role in lateral force and moment generation, and it is essential to understand the relationship between deformation and force. The study also shows how the contact patch displacement is measured and integrated to calculate the forces generated by the tire. Stereo-DIC is applied to measure displacement distribution. Separate testing is performed of a rubber sample from the tire tread area to evaluate tire tread material property, which is then used in combination with strain to calculate forces. Test rig measurements have confirmed the estimated tire forces.
... By increasing the apex length and the carcass width, the vibration energy can be decreased, whereas by increasing the sidewall gauge and the apex hardness, the vibrational energy can be decreased (Lee and Kim, 2008). Sivaramakrishnan et al. (2015) performed an experimental study of the influence of tyre design parameters such as carcass stiffness, tread compound and tread stiffness on the performance of ABS, highlighting that the peak grip, braking stiffness, optimal slip ratio and the shape factor are the main contributing characteristics The braking stiffness is expressed as a combination of carcass stiffness and tread stiffness, where the latter is a dominant factor during the initial braking cycles in the pressure build up phase. The first cycle of braking can cause the most loss in the stopping distance and thus the braking stiffness is a significant parameter in ABS performance. ...
The performance of Anti-lock Brake Systems (ABS) for vehicles deteriorate on rough terrains, due to fluctuations in the angular wheel speeds and in the vertical loading conditions of the tyre caused by the terrain inputs.
In this paper, ABS braking performance on non-deformable rough terrain is investigated by performing experiments and simulations using a testing trailer and a validated multi-body dynamics model. The trailer was constructed using a Land Rover Defender chassis and installed with standard Land Rover braking components including an ABS modulator. It was found in the ABS tests performed, while using a standard Bosch ABS algorithm, that the ABS algorithm failed to perform optimally due to oscillations and irregularities that were present in the measurement of angular wheel speeds. Good correlation is found between the tyre forces measured and the forces simulated using an FTire model in MSC ADAMS software. A powerful platform was created for future off-road ABS investigation and development using both experiments and a simulation platform.
The changes in tire pressure will cause braking force to significantly vary due to the change in the tire-to-road contact during hard braking. The most important reason of this issue is the changes in road contact because of the changes in the vertical stiffness and slip stiffness of tire, as tire pressure varies. Therefore, in this study, it was aimed to investigate the effects of the tire pressure on anti-lock brake system (ABS) control performance through vertical and slip stiffness of tire. For this, first, the friction coefficient extended to tire pressure was integrated into the braking dynamics equations using the magic tire model. In this way, the effects of tire pressure were analytically revealed on braking performance. Then, taking into account the theoretical results, ABS braking tests were carried out with three different tire pressures: higher (38 psi) and lower (25 psi) tire pressure than the nominal (33 psi) tire pressure. In experimental studies, tests were carried out for braking initial speeds 30 and 60 km/h with the same tire pressures in µ-jump road conditions. In this way, the effects of the tire pressure were experimentally investigated on control performance of ABS under critical road conditions. At 33 psi tire pressure, the highest brake pressure was observed when switching to wet roads. At 25 psi tire pressure, the brake pressure did not build up in time. This showed that low tire pressure causes brake pressure to increase with a delay. On the slippery part, the lock-up limit is closer at 38 psi tire pressure. Therefore, it was seen that the decrease and increase in tire pressure have great effect on control performance of ABS under µ-jump road conditions.
Tires play an important role in the performance of vehicular safety systems. Antilock braking system is one of the most important active safety systems that interacts with the tires. Unlike a variety of existing algorithms which are tuned to a specific tire, this research proposes a model-free reinforcement learning-based control algorithm which can adapt to changing tire characteristics and there by effectively utilising the available grip at tire–road interface. The simulation model, consisting of brake actuator dynamics, transportation delays, tire relaxation behaviour, vehicular longitudinal and pitch dynamics, is trained using more than 350,000 random tires. To reduce training time, a parallelisation architecture has been proposed which distributes learning and simulation tasks to different CPU cores. Finally, a conditional variance-based sensitivity analysis with over twelve thousand tires indicate improved grip utilisation at tire–road interface and decreased sensitivity of stopping distance on tire nonlinearity compared to literature version of Bosch algorithm.
Braking performance is a key requirement for tires, significantly affecting the braking distance of vehicles. Considering longitudinal tire dynamics, tire characteristics and parameters, as well as influences from vehicle and ambient conditions have to be identified for an integrated evaluation of tire performance. Various testing methods for identification of tire characteristics are available, yet most of them lack the ability to measure directly at the tire/road contact. Tire sensors have been a popular research topic, which may allow for identification of tire properties during test maneuvers in the contact region. This article features the analysis of longitudinal tire dynamics at full (ABS) braking by means of three 3-axis accelerometers fixed to the inner liner of four different sets of front and rear summer tires. Considering both steady-state and dynamic tire braking properties, skid trailer measurements of force–slip characteristics as well as brake tests with the tire accelerometers are presented for the different tires and compared with each other. Characteristics, affecting the overall braking performance, measured by the tire accelerometers at the contact patch indicate a meaningful correlation to the measured steady-state force–slip characteristics. A basic model-based analysis, utilizing the tire brush model, completes the evaluation of longitudinal tire characteristics with respect to braking performance.
This study aims to provide quantitative insight into the sensitivity of tyre parameters on the performance of the anti-lock braking system (ABS) control algorithms. Unlike conventional sensitivity analysis methods, which depend on a few test cases, in this study, Magic Formula (MF) 6.1 tyre model is used to generate a comprehensive set of thousands of virtual tyres that encompasses all possible combinations of the four main longitudinal parameters. To broaden the scope of impact of this study, two ABS controllers – one based on wheel spin acceleration (literature version of Bosch ABS) and the other based on sliding mode control (SMC) are designed in MATALB-Simulink ® and integrated with IPG Carmaker ® to perform complete vehicle dynamics simulations. Straight-line ABS simulations are performed on dry asphalt road using both the controllers and each test-run is performed for five different set-point longitudinal slip ratios ( λ r e f ). The results of the conditional variance-based sensitivity analysis consisting of 211,250 simulation tests indicate that the tyre peak friction coefficient and shape factor have significant contributions to ABS stopping distance. The sensitivity for stopping distance to tyre parameters varies amongst the controllers. While with Bosch algorithm parameter D almost completely controls the stopping distance, the sliding mode ABS is sensitive to parameters λ r e f , C and D. Tyre parameter interactions indicated by the factor K = B ∗ C ∗ D , though hard to visually interpret, is expounded using global sensitivity analysis metrics.
This paper presents a study - by experimental methods - on the behavior of different classes of passenger cars in the braking process. In the experimental determinations, the parameter values were chosen to characterize the real studies case, commonly encountered, of the passenger cars use in the braking process. Thus, it is considered the experimental determination of the braking ability parameters of the studied passenger cars depending on tire pressure, loading on axles, nature and condition of the rolling surface, tire type (summer or winter) and type of braking system. The way in which behave the passenger cars equipped with winter tires in a situation where the weather requires summer tires at different inflation pressures, also show interest. For the frequency assessment of the brake using in urban areas at different traffic densities it has been used Android applications. The results were represented graphically in order to facilitate theirs comparison.
Tread depth, inflation pressure, tire temperature, and road surface condition are among the most notable factors that have a noticeable effect on the tire force and moment characteristics. They can vary significantly during the operation of a tire and can effectively modify tire (and thus vehicle) performance. This study presents details of an adaptive magic formula (MF) tire model capable of coping with changes to the tire operating condition. More specifically, extensions have been made to the magic formula expressions for tire cornering stiffness and peak grip level, to account for variations in the tire inflation pressure, load, tread-depth and temperature. As a next step, the benefits of using an adaptive tire model for vehicle control system applications is demonstrated through simulation studies for enhanced vehicle control systems using an adaptive tire model in comparison to traditional control systems based on a non-adaptive tire model with fixed model parameters. In particular, this paper investigates the improvements an adaptive tire model would bring into the following vehicle control system strategies: Electronic Stability Control (ESC) system, Brake Torque Vectoring (BTV) system, and Rear Wheel Steer (RWS) system.
In this article, we propose a linear parameterization (LP) for representing the friction in the tire-road interface, suitable for on-line identification. This model was obtained by employing function approximation techniques, which results in an optimization problem to minimize the fitting error between the LP and the nonlinear Burckhardt model. Compared with others LPs proposed in the literature, the optimal LP features a reduced number of parameters and good approximation capabilities. Moreover, the proposed model can be identified though linear identification techniques, simplifying the on-line peak friction estimation. Simulation results obtained with a vehicle simulator demonstrates the effectiveness of the proposed parameterization.
The definitive book on tire mechanics by the acknowledged world expert. © 2012 Hans Pacejka Published by Elsevier Ltd All rights reserved.
In this article, we propose a linear parameterization (LP) for representing the friction in the tire-road interface, suitable for on-line identification. This model was obtained by employing function approximation techniques, which results in an optimization problem to minimize the fitting error between the LP and the nonlinear Burckhardt model. Compared with others LPs proposed in the literature, the optimal LP features a reduced number of parameters and good approximation capabilities. Moreover, the proposed model can be identified though linear identification techniques, simplifying the on-line peak friction estimation. Simulation results obtained with a vehicle simulator demonstrates the effectiveness of the proposed parameterization.
In this new paperback edition of Tyre and Vehicle Dynamics, theory is supported by practical and experimental evidence. Pacejka provides both basic and advanced explanations of the pneumatic tyre and its impact on vehicle dynamic performance. The book shows the way in which tyre models are incorporated in vehicle models and how important tyre influence is on overall vehicle behaviour. Those working in any industry involving equipment with tyres will continue to find this book both extremely relevant and useful. * Written by a world expert in tyre dynamics * Covers both basic and advanced tyre modelling and simulation, including case studies of application examples and chapter exercises * Indispensable for any engineer working in vehicle system dynamics and for any industry involving equipment with tyres.
A tire's torsional dynamics couple the responses of wheel/hub inertia to that of the ring/belt inertia. Depending on the effective stiffness, damping, and mass distribution of the tire, the ensuing deflections between the wheel and the ring can cause significant errors in the estimation of the tire's longitudinal slip from wheel speed measurements. However, this remains the established approach for constructing anti-lock braking system (ABS) control algorithms. Under aggressive braking events, the errors introduced by torsional dynamics may significantly affect the ABS algorithm and result in less than optimal braking performance. This article investigates the interaction of tire torsional dynamics and ABS control using a comprehensive system model that incorporates sidewall flexibility, transient and hysteretic tread-ground friction effects, and the dominant dynamics of a hydraulic braking system. It considers a wheel/hub acceleration-based ABS controller that mimics the working steps of a commercial ABS algorithm. Results from multiple sensitivity studies show a strong correlation of stopping distances and ABS control activity with design parameters governing tire/wheel torsional response and the filter cutoff frequency of the wheel acceleration signals used by the controller.
Easy-to-use tire models for vehicle dynamics have been persistently studied for such applications as control design and model-based on-line estimation. This paper proposes a modified combined-slip tire model based on Dugoff tire. The proposed model takes emphasis on less time consumption for calculation and uses a minimum set of parameters to express tire forces. Modification of Dugoff tire model is made on two aspects: one is taking different tire/road friction coefficients for different magnitudes of slip and the other is employing the concept of friction ellipse. The proposed model is evaluated by comparison with the LuGre tire model. Although there are some discrepancies between the two models, the proposed combined-slip model is generally acceptable due to its simplicity and easiness to use. Extracting parameters from the coefficients of a Magic Formula tire model based on measured tire data, the proposed model is further evaluated by conducting a double lane change maneuver, and simulation results show that the trajectory using the proposed tire model is closer to that using the Magic Formula tire model than Dugoff tire model.
The designs of commercial Anti-Lock Braking Systems often rely on assumptions of torsionally rigid tire-wheel assemblies. However, some recent tire/wheel technologies often involve lower torsional stiffnesses that cannot be captured well using these rigid wheel assumptions. This paper presents both simulation and experimental analysis of the interaction between a typical ABS controller and tire torsional dynamics. The simulation work includes a comprehensive model that incorporated sidewall flexibility, transient and hysteretic tread-ground friction effects, and the dominant dynamics of a hydraulic braking system. The experimental tests were conducted on a quarter-vehicle ABS test fixture built around a chassis dynamometer. Sensitivity studies are completed through changes in the tire/wheel properties such as wheel inertia, torsional stiffness and ABS controller properties such as the controller’s filter cutoff frequency applied to the wheel speed signals. The results showed strong interactions between the tire’s torsional natural frequency and the filter cutoff frequency of the controller.
In this paper, an overview of the TNO MF-SWIFT model is given. After an historical overview of the model development and the intended range of application, the model is described briefly. Next, the implementation in multibody and other simulation software is discussed, including also the available road models. After that, the parameterization of the tire model is described and the available identification tool is discussed. Finally, comments are given on the TMPT from the TNO point of view.