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This study introduces fBrake, a novel simulation method now designed for use in periodic technical inspections of M1 and N1 vehicle categories, addressing challenges posed by Directive 2014/45/EU. The directive mandates that braking efficiency must be measured relative to the vehicle's maximum mass, which often results in underperformance during inspections due to vehicles typically being unladen. This discrepancy arises because the maximum braking forces are proportional to the vertical load on the wheels, causing empty vehicles to lock their wheels prematurely compared to laden ones. fBrake simulates the braking forces of unladen vehicles to reflect a laden state by employing an optimal brake-force distribution curve that aligns with the vehicle's inherent braking behavior, whether through proportioning valves or through electronic brake distribution systems in anti-lock-braking-system-equipped vehicles. Our methodology, previously applied to heavy vehicles, involved extensive experimentation with a roller brake tester, comparing the actual braking performances of dozens of vehicles to those of their simulated counterparts using fBrake. The results demonstrate that fBrake reliably replicates the braking efficiency of laden vehicles, validating its use as an accurate and effective tool for braking system assessments in periodic inspections, irrespective of the vehicle's load condition during the test. This approach ensures compliance with regulatory requirements while enhancing the reliability and safety of vehicle inspections. [ABSTRACT FROM AUTHOR]

Vehicle mobility is an increasingly important issue today, even in the military field. Mobility depends on the condition of the vehicle, the route and, of course, the experience of the driver. Vehicle failures and damage are very common in military operations. It is therefore important to find out how these failures and damage can affect mobility. One of the essential parts of a vehicle is the braking system. The authors therefore decided to investigate what is the effect of a malfunctioning brake system on emergency braking behaviour of a special vehicle in a curvilinear movement. Simulation tests were performed based on an experimentally validated model. The tests were performed with a wheeled vehicle on three different surfaces: concrete, wet asphalt, and ice. The experimental conditions were given as follows - the braking process was considered for a braking system with ABS on and off and for two states of braking system sufficiency (8 braked wheels or 4 rear braked wheels). These tests allowed us to analyse the effect of the extent of the damage on safety, in this case the stopping of the vehicle on a specified curved route. The results of braking and stability on different surfaces and under given conditions are evaluated and described in this paper. On the basis of the results, it is possible to prepare training programmes (scenarios) for drivers of special vehicles for the purpose of driving techniques in critical situations. [ABSTRACT FROM AUTHOR]

In long-term operation, the gradual degradation process of automotive friction pads significantly affects the expected performance of mechanical equipment. In addition, the intrinsic correlations between friction properties and the multi-stage degradation process have been mostly ignored, leading to less accurate prediction of results under multifactorial influences on working conditions. In this paper, we propose a novel prediction method using the CNN-BiLSTM-Att model to overcome the problem. The model uses CNN to extract the friction features in the processed data, and combines with BiLSTM to evaluate the time series features hidden in the friction data. To improve the prediction accuracy, the attention mechanism is fed into the proposed model, which has the advantage of automatically assigning appropriate weights to the hidden layer states to distinguish the importance of different data features. Compared with other machine learning algorithms, the method has high prediction accuracy and can provide reference for braking. [ABSTRACT FROM AUTHOR]

Vehicle mobility is an increasingly important issue today, even in the military field. Mobility depends on the condition of the vehicle, the route and, of course, the experience of the driver. Vehicle failures and damage are very common in military operations. It is therefore important to find out how these failures and damage can affect mobility. One of the essential parts of a vehicle is the braking system. The authors therefore decided to investigate what is the effect of a malfunctioning brake system on emergency braking behaviour of a special vehicle in a curvilinear movement. Simulation tests were performed based on an experimentally validated model. The tests were performed with a wheeled vehicle on three different surfaces: concrete, wet asphalt, and ice. The experimental conditions were given as follows – the braking process was considered for a braking system with ABS on and off and for two states of braking system sufficiency (8 braked wheels or 4 rear braked wheels). These tests allowed us to analyse the effect of the extent of the damage on safety, in this case the stopping of the vehicle on a specified curved route. The results of braking and stability on different surfaces and under given conditions are evaluated and described in this paper. On the basis of the results, it is possible to prepare training programmes (scenarios) for drivers of special vehicles for the purpose of driving techniques in critical situations.

Due to their superior capabilities for manufacturing lightweight automotive components, aluminium metal matrix composites have gained a lot of attention in the last few years. Aluminium metal matrix composites are an exceptional class of metal matrix composites that can solve all the major problems related to the automobile industry. Aluminium matrix composites in the disc braking system have already been employed and studied by many scientists. However, the developed materials are not yet always sufficiently accurate and reliable. In this article, a new enhanced metal matrix composite material is used and studied to improve the efficiency of an ordinary car's braking system. To improve the accuracy of the designated braking system, an innovative hybrid aluminium matrix composite (Al6061/SiC/Gr)-based brake rotor has been developed, and its effectiveness has been determined by finite element analysis. From the simulation, the product performance confirmed that the hybrid aluminium matrix composite (Al6061/SiC/Gr)-based brake rotor has the potential to replace the standard cast iron brake disc. The new enhanced hybrid composite material used in this study can be used for the efficient design of various braking parts. [ABSTRACT FROM AUTHOR]

This study uses TruckSimTM to model disc brakes and drum brakes on a fully loaded truck semi-trailer to study the performance of each brake type as downgrades and speeds vary. The brake performance is measured based on braking distance. A simplified economic comparison based on life cycle cost analysis to determine which road and vehicle conditions give rise to the cost-effectiveness of disc brakes is performed. The studies suggest that disc brakes shorten braking distances by 10-20%. They also suggest that the percentage reduction in braking distance as speed increases and downgrade gets steeper is approximately 12-19%. Evidence is provided that trucking companies operating their vehicles in steep terrain and at high speeds with disc brakes could benefit from 12-80% in long-term cost savings. Finally, at the societal level, by preventing crashes arising from rear-end collisions and runaway truck incidents, disc brakes save at least $649 million annually. [ABSTRACT FROM AUTHOR]

This study uses TruckSimTM to model disc brakes and drum brakes on a fully loaded truck semi-trailer to study the performance of each brake type as downgrades and speeds vary. The brake performance is measured based on braking distance. A simplified economic comparison based on life cycle cost analysis to determine which road and vehicle conditions give rise to the cost-effectiveness of disc brakes is performed. The studies suggest that disc brakes shorten braking distances by 10-20%. They also suggest that the percentage reduction in braking distance as speed increases and downgrade gets steeper is approximately 12-19%. Evidence is provided that trucking companies operating their vehicles in steep terrain and at high speeds with disc brakes could benefit from 12-80% in long-term cost savings. Finally, at the societal level, by preventing crashes arising from rear-end collisions and runaway truck incidents, disc brakes save at least $649 million annually.

This paper presents some problems concerning the present trends in the field of aircraft braking systems. New solutions like electro-mechanical or electro-hydrostatic actuators are considered the future, but some big aircraft producers do not renounce yet to classical electro-hydraulic braking systems. New solutions are not generally accepted, they have to prove their reliability and that they bring considerable more advantages than penalties. [ABSTRACT FROM AUTHOR]

This paper is focused on the theoretical study of heat conduction in the multi-brake system of the automated guided vehicle (AGV). The study aims to compare the amount of heat generated during braking from 10 m/s until a stop in a brake system based on organic and ceramic friction material. The theoretical study of heat conduction is solved in Matlab computational software using a derived Fourier partial differential equation for nonstationary heat conduction. The results of the simulation of the heat conduction are shown in the diagrams and indicate not only the temperature dependence in the period during braking from a speed of 10 m/s to a stop but also the amount of heat accumulated in the steel disc during braking. The simulation results show that braking in both brake systems generates approximately the same amount of heat. The difference occurs in the period of thermal activity, which was influenced by the length of the braking distance. This is caused by a coefficient of friction that significantly affects the final braking result. Finally, it can be stated that the brake system based on organic material must be equipped with a steel disc with a minimum thickness of 8 mm. This is because the brake system based on organic friction material has a set temperature limit of 160 degrees Celsius. The results presented in this study will help an engineer constructor to choose the right procedures and parameters of geometry for designing the mentioned braking system for the considered AGV.

This paper is focused on the theoretical study of heat conduction in the multi-brake system of the automated guided vehicle (AGV). The study aims to compare the amount of heat generated during braking from 10 m/s until a stop in a brake system based on organic and ceramic friction material. The theoretical study of heat conduction is solved in Matlab computational software using a derived Fourier partial differential equation for nonstationary heat conduction. The results of the simulation of the heat conduction are shown in the diagrams and indicate not only the temperature dependence in the period during braking from a speed of 10 m/s to a stop but also the amount of heat accumulated in the steel disc during braking. The simulation results show that braking in both brake systems generates approximately the same amount of heat. The difference occurs in the period of thermal activity, which was influenced by the length of the braking distance. This is caused by a coefficient of friction that significantly affects the final braking result. Finally, it can be stated that the brake system based on organic material must be equipped with a steel disc with a minimum thickness of 8 mm. This is because the brake system based on organic friction material has a set temperature limit of 160 degrees Celsius. The results presented in this study will help an engineer constructor to choose the right procedures and parameters of geometry for designing the mentioned braking system for the considered AGV. [ABSTRACT FROM AUTHOR]

The paper presents a new methodology for calculating the optimal linear distribution of braking forces for a three-axle trailer with “walking beam” and “bogie” suspension of the rear axle assembly that will meet the requirements of the new European legislation, EU Directive 2015/68. On this basis, a computer program for selecting the linear distribution of braking forces between axles has been developed. The presented calculations and simulation results of the braking process can be used in the design process to select the parameters of the wheel braking mechanisms and then the characteristics of the pneumatic valves of the braking system. The adaptation of the braking system of agriculture trailers is a very important factor for improving the safety of the transportation systems.

Copyright of Maintenance & Reliability / Eksploatacja i Niezawodność is the property of Polish Scientific & Technical Society Consumables, Polish Maintenance Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Although the antilock braking system (ABS) has been commonly used in electric vehicles (EVs), most of the vehicles still use the traditional hydraulic‐based disc brake in which the driving and the braking systems are two individual modules. A novel integrated driving and braking control system with an ABS for EVs was developed, and an electric scooter was used as the experimental object. While braking, the motor acts as a generator. The autonomously generated inertial energy was used to generate a reverse magnetic braking torque and realise an antilock braking control with fast response. Compared with the existing regenerative and short‐circuit braking methods, the proposed method uses back electromotive force to yield a reverse magnetic braking torque in a sophisticated manner. In the proposed method, a capacitor‐aided regenerative braking strategy was used in an antilock braking controller. For the ABS control design, the slip ratio was maintained within an optimal range for obtaining the best tyre–road surface adhesion using a fuzzy slip ratio controller to prevent the wheel from skidding during emergency braking. For real‐world verification, the electric scooter was subjected to various on‐road tests to examine the performance of the proposed method. [ABSTRACT FROM AUTHOR]

Copyright of Computer Measurement & Control is the property of Magazine Agency of Computer Measurement & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cooperative braking control is a very important operation in vehicle platoon control for developing intelligent transportation systems, which can effectively increase road capacity, decrease safety hazard, and avoid serial rear-end collisions. This paper focuses on cooperative braking control of autonomous vehicles, the objectives of which are to ensure intervehicles keep within the safe spacing range and rapidly, smoothly, and accurately stop at the desired target stopping positions with zero velocity. To achieve these goals, a three-vehicle platoon framework is presented and the corresponding dynamic model is established based on only information about front-end and rear-end sensors of vehicles, so communication is not needed. The explicit solutions on the three-vehicle platoon are derived by rigorous convergent analysis and detailed proof, such that intrinsic characteristic of the interconnected vehicles is revealed. The resulting convergent conditions and convergent rate are obtained under three cases including: 1) considering internal virtual forces; 2) considering external braking forces; and 3) considering both the internal virtual forces and external braking forces simultaneously. Moreover, an example is further provided to verify that the derived convergence conditions are effective and sufficient under the different controller parameter selection. These results can provide a solution for a wide class of interconnected systems and a guide for controller design to select control parameters in real engineering applications. Simulation results demonstrate the validity of the proposed control approaches. [ABSTRACT FROM PUBLISHER]

Results of research on the hazard posed by polycyclic aromatic hydrocarbons contained in the dusts emitted from motor vehicle braking systems have been presented. The polycyclic aromatic hydrocarbons (PAHs) constitute a group of chemical compounds that pose a serious danger to the human health, chiefly because of their carcinogenic properties. Investigations into the issue of environmental pollution with polycyclic aromatic hydrocarbons generated by motor vehicle traffic were carried out in connection with the work being done at PIMOT on systems to reduce dust emission from motor vehicle braking systems. The investigations included determination of PAH contents of the dust emitted from vehicle braking systems as well as the PAH concentrations in the indoor air in a room with the stand for testing dust emissions from braking systems and in the duct to carry away gases from that room. Moreover, the PAH contents of soil were measured in the context of location of the soil sampling points in relation to traffic routes. The PAH contents were measured in Warsaw and in Zabrze. The investigation results confirmed that PAHs considered as being most harmful to the human health due to their carcinogenic properties were actually present in the dusts emitted from braking systems. The PAH contents of soil were found to be very sensitive to the location of the soil sampling points in relation to traffic routes and this is a confirmation of the thesis that motor traffic is an important source of environmental pollution with polycyclic aromatic hydrocarbons. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this paper is to report a study in which creative design concepts have been applied to automotive brake rotor design. Design/methodology/approach – The literature review on creative design concepts and braking system scenario has been carried out. By studying the existing brake rotors and applying creative design concepts, modified rotor designs have been developed. Findings – The experience gained out of the study indicated that braking efficiency and durability of the braking system can be significantly improved by the adoption of proposed designs. Research limitations/implications – The research has been carried out for an automotive passenger car. The findings of this research work could be extended to similar models of buses and trucks. Practical implications – The usage of the proposed designs reduces the driver’s effort in braking and adds significantly to the life of the rotors. Originality/value – A case study has been reported to indicate the application of creative design concepts for enhancing the efficiency of automotive braking system in cars. [ABSTRACT FROM AUTHOR]

Carbon/carbon–silicon carbide (C/C–SiC) composites, as a promising material for brake disks, have been widely concerned by researchers. In this work, the C/C–SiC composite that has potential applications in future advanced braking systems has been fabricated by combining low temperature compression molding (LTCM) and liquid silicon infiltration (LSI). The effects of the carbon fibers (C f ) dispersion and LSI on the properties of the C/C–SiC composite have been investigated. The results demonstrate that the as-prepared composite with a high density of 2.3 g cm −3 and low open porosity of 6% exhibits a high bending strength of 120 MPa and compressive strength of 153 MPa. Moreover, it displays a “False plasticity” phenomenon, indicating the excellent mechanical properties. Additionally, a stable friction coefficient of 0.33 has been also obtained, which demonstrates that the chattering phenomenon can be effectively controlled to obtain comfortable driving conditions during the brake process. [ABSTRACT FROM AUTHOR]

The paper deals with the modern braking systems of mineral substances hauling vehicles. A description of the technical and constructive characteristics of the braking systems as well as of the means of testing and checking their efficiency is also brought forward. Testing the braking systems is necessary to verify the braking performance of vehicles in order to ensure the driving safety. [ABSTRACT FROM AUTHOR]

As Crash Imminent Braking (CIB) systems have been introduced to the passenger vehicle market segment, there is an immediate need to develop a standardized performance scoring system which enables an objective comparison of similar CIB systems implemented across various vehicle platforms. It is desirable that this standard is adopted by the entire automotive industry to further advance CIB technologies. It is also a valuable reference for consumers to compare the safety of different vehicles. This paper describes an approach for the establishment of such a standard to evaluate and compare the performance of CIB systems. A set of testing scenarios is proposed for the performance evaluation of CIB systems. Subjective and arguable test scenarios are avoided as much as possible. The applicability of the proposed scoring system is demonstrated with the data collected from some proposed testing scenarios in the evaluation of a 2011 model-year passenger vehicle equipped with a CIB system. [ABSTRACT FROM PUBLISHER]

Purpose |!|#8211; The purpose of this paper is to describe some tribological experiments which were executed to find the influence of braking pressure on tribological performance of non-asbestos brake shoe used in mine hoister during its emergency braking. Design/methodology/approach |!|#8211; The WSM-3 non-asbestos brake shoe, which has been widely used in mine hoister, was selected as experimental material. Some tribological experiments of the brake shoe sliding on 16Mn steel were investigated on the X-DM friction tester by simulating of emergency braking conditions of mine hoister. Three kinds of tribological indexes: friction coefficient, stability coefficient of friction coefficient, and wear rate were considered to score the tribological performance and the morphology of worn surfaces were observed through the S-3000N scanning electron microscopy (SEM) to explore the tribological mechanisms. Findings |!|#8211; It was found first, that the instant friction coefficient is not constant during emergency braking. After a short climbing period, it rises gradually to steady value. Second, with the increasing of braking pressure, the mean friction coefficient rises first then falls, while its stability coefficient falls gradually. The wear rate rises continuously with the braking pressure increasing. Also, the rising velocity of wear rate at high pressure is higher than it is at low pressure. Third, the instant surface temperature rises first then falls during braking and the mean surface temperature rises continuously with the braking pressure increasing. Originality/value |!|#8211; It is found that the increasing of braking pressure within a certain range is helpful for achieving a high friction coefficient and a steady wear rate. But too high pressure will cause contrarily the falling of frictional performance and serious of wear performance. So it is not reliable to rise the braking pressure without limited during emergency braking. [ABSTRACT FROM AUTHOR]

A mathematical model of the trailer relay emergency valve used in the pneumatic braking systems of agricultural trailers has been presented. The differential equations of the model allow for the inertia of control elements, static and kinetic friction, and heat exchange in individual valve chambers. The developed mathematical valve model was used for simulation of the transient processes in the dual-line braking system of a single-axle agricultural trailer. The computer models for individual components of the braking system were made within the program MATLAB/Simulink in the form of S-function-type functional structural blocks based on original algorithms. The positive results of validation of the trailer braking system computer model show a potential for a wider use of dynamic computations in the computer-aided process of designing pneumatic vehicle braking systems. [ABSTRACT FROM AUTHOR]

Abstract: We show here the design and preliminary experimental evaluation steps of a fuzzy controller for the pressure loop of a proposed new Airbus A310/A320 modular braking system. The results indicated that two main requirements of this system could be achieved: [•] pressure control with high robustness in the case of hydraulic load fluctuations, and; [•] highly modular characteristics, since the same fuzzy controller can be used in both aircraft by doing only a simplified tuning of one of its gain parameters. [Copyright &y& Elsevier]

Abstract: Analytical model is developed in this Note to determine the 3D temperature distribution in a rotating disc subjected to multiple surface heat sources. The Fourier and Hankel integral transforms are used to perform the analytical calculations. The expression obtained by this way is explicit and allows one to compute the temperature without restriction on the rotating speed and the physical properties values. Some practice industrial applications are concerned by this calculation such the contact between pad and disc in braking systems, or the pin-on-disc tribological devices. To cite this article: A. Hocine et al., C. R. Mecanique 337 (2009). [Copyright &y& Elsevier]

Composite ceramic materials reinforced with carbon fibers are interesting materials because of their excellent mechanical and thermo-physical properties, which make them appropriate for many applications, including re-entry shields, rocket nozzles, disc brakes, and prosthetic devices. For all these purposes, many different types of such materials have been developed, for example, carbon/silicon-carbide or carbon/carbon-silicon-carbide composites that are commonly produced from carbon/carbon composites impregnated with liquid silicon by the liquid-silicon infiltration (LSI) process. In this work, a new ceramic matrix composite friction material for brake discs was developed that combines a high fracture toughness with good oxidation and abrasion resistance, good thermal conductivity, and the appropriate friction characteristics. For the production of such materials, the “dual-matrix” approach combined with reactive sintering was used. The materials have suitable mechanical properties and the braking discs have appropriate coefficient of friction and very low wear rate. [ABSTRACT FROM AUTHOR]