Browse Topic: Air brakes

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Test JSW2-6715 NewJSW26715_202501 (Current)1/17/2025
testing
Ground Vehicle European Prospect Committee
400Hz High Speed Static Transfer Switch2008-01-287711/11/2024
The objective of this project was to replace electromechanical power line contactors with a Static Transfer Switch (STS) to improve the transfer of electrical power between aircraft generators and decrease required maintenance. The switch requirements include high reliability, lightweight, and high speed (less than 15mS) power transfer. An STS can shorten the bus transfer time to less than the “ride-through” of aircraft electronic loads and therefore have the ability to control and transfer electrical power while maintaining critical mission requirements. The content of this paper and presentation will discuss the initial problem, the research and development approach, design, and initial testing of the STS.
Cooper, Ronald C., Cooper, Evan C.
Automotive Air Brake Line Couplers (Gladhands)J318_202106 (Current)6/10/2021
This SAE Recommended Practice is intended to provide design, interchangeable dimensions, testing procedures, performance requirements, and minimum identification for gladhand-type air line couplers used to connect the brake systems of trucks, truck-tractors, trailers, and dollies when these vehicles are joined to operate as a combination unit.
Truck and Bus Brake Supply and Control Components Committee
Thread SealantsJ1615_202101 (Current)1/27/2021
Male pipe threads, including male dryseal pipe threads, when made into assemblies or installed into ports, will generally leak if not covered with a sealant. This SAE Recommended Practice is intended as a guide to assist designers and/or users in the selection and application of various types of thread sealants. The designers and users must make a systematic review of each type and application and then select the sealant to fulfill the requirements of the application. The following are general guidelines and are not necessarily a complete list.
Air Brake Tubing and Tube Ftg Committee
Validation of Compressibility Test Systems for Friction MaterialsJ3079/1_202101 (Current)1/13/2021
This SAE Recommended Practice (RP) applies to the validation process for test systems used to measure deflection (compressibility, creep, or swell and growth) of friction materials and friction material assemblies. The materials or assemblies can fit passenger cars, light trucks, and commercial vehicles equipped with hydraulic or air brake systems, using disc or drum brakes.
Brake Linings Standards Committee
Air Brake Performance and Wear Test Code Commercial Vehicle Inertia DynamometerJ2115_202008 (Current)8/20/2020
This SAE Standard provides test procedures for air and air-over-hydraulic disc or drum brakes used for on-highway commercial vehicles over 4536 kg (10000 pounds) GVWR. This recommended practice includes the pass/fail criteria of Federal Motor Vehicle Safety Standard No. TP-121D-01.
Truck and Bus Foundation Brake Committee
Parking Brake Control Identification - Vehicles with Hydraulic Brake Systems and Automatic TransmissionsJ2688_202007 (Current)7/13/2020
The scope and purpose of the SAE Recommended Practice is to provide standards for the control and indication of parking brakes in hydraulic braked vehicles over 4540 kg (10000 lb) GVWR. This recommended practice pertains to automatic transmission applications and supplements the SAE J915 recommended practice. This recommended practice does not address parking brake system performance. Parking brake system performance, both static and dynamic conditions, is the responsibility of the OEM vehicle manufacturer or manufacturers that modify the vehicle by adding special vocational required equipment (such as but not limited to outriggers, cranes, etc.).
Truck and Bus Hydraulic Brake Committee
15 Pole Connector Between Towing Vehicles and Trailers with 12 Volt Nominal SupplyJ2691_202002 (Historical)2/25/2020
This SAE Standard establishes the minimum construction and performance requirements for a 15 pole connector between towing vehicles and trailers, for trucks, trailers, and dollies, for 12 VDC nominal applications in conjunction with SAE J2742. The connector accommodates both power and ISO 11992-1 signal circuits along with dual ground wires to accommodate grounding requirements within the constraints of the SAE J2691 terminal capacity.
Truck and Bus Electrical Systems Committee
Development challenges of hydraulic brakes for commercial vehicles2019-36-00131/13/2020
The automotive research and development environment is increasingly challenging and complex, full of new technologies, regulations and customized customer needs. In addition, the cargo transportation market is very dynamic and competitive, becoming complex the strategies for companies in this segment. According to Anfavea (2018), this trend, especially in large urban centers, has driven the intention to use light commercial vehicles to capillize deliveries in destinations with a high demographic concentration and traffic limited to medium and heavy vehicles. In this scenario, the demand for diversified products is increasing in order to overcome the main tradeoff: “minimizing the size of the trucks and maximize the load capacity”. It brings the number of complex projects. The brake system is greatly impacted in these developments mainly because light commercial vehicles are situated in a weight range that we can call "identity crisis" if on the one hand they need an upgrade compared to a conventional car and use the hydraulic brake on the other one need a downgrade of a medium or heavy truck that brings robustness and pneumatic brakes. The definition of the type of assistance is a determining factor, hydraulic brake; pneumatic brake or a hybrid brake (air over hydraulic). Each type has its advantages and disadvantages, which are directly related to the vehicle's application such as installation package, serviceability, service brake costs and performance and especially parking brake. This work shows the study and development of the brake system including the detailed presentation of a dry caliper, implemented as disruptive innovation technology. It also has a new concept applied to a commercial vehicle, developed in Brasil and used as footprint own knowledge for the specific needs of the market and provides a very cost-benefit commitment for the customer, yet brings the wished confidence of the parking brake function for drivers.
Vetter, Narã Vieira, Carlos de Oliveira, Antonio, Fontes, Eduardo Henrique Souza, Nogueira, Felipe, Fonseca, Guilherme Henrique, Nuss de Souza, Luis Fernando, Oliveira dos Reis, Rodrigo de, Manenti, Vangelo Cardoso
Automotive Air Brake Line Couplers (Gladhands)J318_201911 (Historical)11/20/2019
This SAE Recommended Practice is intended to provide design, interchangeable dimensions, testing procedures, performance requirements, and minimum identification for gladhand-type air line couplers used to connect the brake systems of trucks, truck-tractors, trailers, and dollies when these vehicles are joined to operate as a combination unit.
Truck and Bus Brake Supply and Control Components Committee
Braking Control Strategy Based on Electronically Controlled Braking System and Intelligent Network Technology2019-01-503811/4/2019
In order to solve the coupling problems between braking safety, economical efficiency of braking and the comfort of drivers, a braking control strategy based on Electronically Controlled Braking System (EBS) and intelligent network technology under non-emergency braking conditions is proposed. The controller utilizes the intelligent network technology’s characteristics of the workshop communication to obtain the driving environment information of the current vehicle firstly, and then calculate the optimal braking deceleration of the vehicle based on optimal control method. The strategy will distribute the braking force according to the ideal braking force distribution condition based on the EBS according to the braking deceleration; the braking force will be converted to braking pressure according to brake characteristics. Computer co-simulations of the proposed strategy are performed, the strategy is verified under different initial speeds. The results show that the strategy enables the vehicle to stop within a safe distance, keeps the brake deceleration as smooth as possible for better braking comfort while at the same time obtaining better braking economy by increasing braking efficiency under different initial speeds.
Zheng, Hongyu, Li, Rui
Research on Integrated Performance Design for the Braking System2019-01-21209/15/2019
Medium or higher commercial vehicles weight will be increased by 5 to 6 times compared to kerb weight depending on their load carrying capacity. Therefore, a pneumatic braking device is used that produces a greater braking force than hydraulic pressure. Pneumatic braking system is a device that performs mechanical braking using air pressure and shall be designed to an appropriate level, taking into account the multi-physics of air and mechanical phenomena. In addition, the dynamics of the vehicle during braking should be considered due to different vehicle behavior depending on the load carrying capacity. This study utilizes SIL(Software In the Loop) for a comprehensive review of the pneumatic braking performance of vehicles.
Han, Wookhyun, Yang, Kee-Young
Brake Block Effectiveness RatingJ1802_201906 (Current)6/6/2019
This SAE Recommended Practice provides the test procedure and methods to calculate the effectiveness of brake blocks, using an inertia dynamometer. To minimize testing variability, and to optimize standardization and correlation, a single, high volume size of brake block is specified (FMSI No. 4515E) and evaluated in a reference S-cam brake assembly of 419 mm x 178 mm (16.5 in x 7.0 in) size, using a specified brake drum.
Truck and Bus Foundation Brake Committee
Inertia Dynamometer Rotor Crack Test Procedure for Air Disc BrakesJ3080_201905 (Current)5/17/2019
This Recommended Practice applies to commercial vehicles equipped with air disc brakes and above 4536 kg of Gross Vehicle Weight Rating. Other assessments on the friction material or rotor related to wear, durability, correlation to product life, noise, judder, compliance to specific regulations, etc., are not part of this RP (Recommended Practice).
Truck and Bus Foundation Brake Committee
FMVSS 105 Inertia Brake Dynamometer Test Procedure for Vehicles Above 4540 kg GVWRJ2684_201812 (Current)12/5/2018
This Recommended Practice is derived from the FMVSS 105 vehicle test and applies to two-axle multipurpose passenger vehicles, trucks, and buses with a GVWR above 4540 kg (10000 pounds) equipped with hydraulic service brakes. There are two main test sequences: Development Test Sequence for generic test conditions when not all information is available or when an assessment of brake output at different inputs are required, and FMVSS Test Sequence when vehicle parameters for brake pressure as a function of brake pedal input force and vehicle-specific loading and brake distribution are available. The test sequences are derived from the Federal Motor Vehicle Safety Standard 105 (and 121 for optional sections) as single-ended inertia-dynamometer test procedures when using the appropriate brake hardware and test parameters. This recommended practice provides Original Equipment Manufacturers (OEMs), brake and component manufacturers, as well as aftermarket suppliers, results related to brake output, friction material effectiveness, and corner performance in a laboratory-controlled test environment. The test sequences include different dynamic conditions (braking speeds, temperature, and braking history as outlined in the FMVSS 105); inertia loads equivalent to the vehicle’s LLVW and GVWR; fully operational, partial failure, and failed system conditions. All applicable sections of the FMVSS 105 are included. Optional sections include: parking brake output, water recovery, TP-121D dynamometer retardation, and 32 km/h (20 mph) stops to simulate Federal Motor Carrier Safety Administration (FMCSA) requirements. This recommended practice does not evaluate or quantify other brake system characteristics such as wear, noise, judder, ABS performance, or braking under extreme temperatures or speeds. Minimum performance requirements are not part of this recommended practice. Consistency and margin of pass/fail of the minimum requirements related to stopping distance or equivalent deceleration levels of the FMVSS 105 vehicle test can be assessed as part of the project in coordination with the test requestor when using the appropriate vehicle information and vehicle dynamics modeling. Nevertheless, this procedure and its results do not replace the vehicle-level test to demonstrate compliance to FMVSS (105 for hydraulic brake systems, or 121 for air-over-hydraulic brake systems), or other mandatory regulations (like ECE R13 or equivalents).
Truck and Bus Hydraulic Brake Committee
High-Preload Deflection and Compressibility Test Procedures for Friction MaterialsJ2468_201811 (Current)11/12/2018
This standard specifies a method for testing and measuring the deflection of friction materials assemblies and compressibility of friction materials. This standard applies to disc brake pad assemblies and its coupons or segments, brake shoe lining and its coupons or segments, and brake blocks segments used in road vehicles. This SAE test method is consistent in intent with the ISO 6310 and the JIS 4413.
Brake Linings Standards Committee
Cartridge CavityJ2494/4_201810 (Historical)10/30/2018
This SAE Standard covers complete general and dimensional data for the manufacture of, T6061-T6 Aluminum cavities designed to receive Push To Connect threadless fittings known as “cartridges“, for air brake applications. This document is not intended to specify or recommend any style or manufacture of such cartridges but to establish uniform cavity dimensions for interchangeability purposes.
Air Brake Tubing and Tube Ftg Committee
Stability Analysis of Combined Braking System of Tractor-Semitrailer Based on Phase-Plane Method02-11-02-00126/4/2018
An analysis method for the stability of combined braking system of tractor-semitrailer based on phase-plane is investigated. Based on a 9 degree of freedom model, considering longitudinal load transfer, nonlinear model of tire and other factors, the braking stability of tractor-semitrailer is analyzed graphically on the phase plane. The stability of both tractor and semitrailer with different retarder gear is validated with the energy plane, β plane, yaw angle plane and hinged angle plane. The result indicates that in the long downhill with curve condition, both tractor and semitrailer show good stability when retarder is working at 1st and 2nd gear, and when it is at 3rd gear, the tractor is close to be unstable while semitrailer is unstable already. Besides, tractor and semitrailer both lose stability when retarder is working at the 4th gear.
He, Ren, Jing, Zhecheng, Shen, Xiaomin
Truck Brake Failure: Differences between Failure Modes for Drum and Disc Brakes2018-01-05284/3/2018
On-highway heavy trucks are fitted with air disc brakes with increasing frequency. Disc brakes and traditional air drum brakes have different adjustment and heat dissipation characteristics. These differences lead to different failure modes when overheated. This paper describes how adjustment and other in-use factors affect the general braking capability of on-highway trucks fitted with disc and drum brakes. Simulations of a loaded tractor-trailer on a long, down-hill grade are used to predict brake temperature increase over time, and how that temperature increase can result in a runaway condition. The tractor and trailer are modeled with both traditional drum brakes and new disc brakes to illustrate operational differences between the two brake types.
Day, Terry D.
Automotive Pipe FittingsJ530_201803 (Historical)3/18/2018
This SAE Standard includes complete general and dimensional specifications for those types of pipe fittings commonly used in the automotive and other mass production industries where the use of lubricants or sealers is objectionable. The automotive pipe fittings shown in Figures 1 to 17 and Tables 1 to 6 are intended for general automotive and similar applications involving low or medium pressures or in conjunction with automotive tube fittings in piping systems.
Air Brake Tubing and Tube Ftg Committee
Brake System Regulations and Standards Review and Comparison Focused on Europe, NA and SA Markets2017-01-25349/17/2017
Considering that the most part of commercial vehicles are equipped with air brakes it is very important assure specific technical requirements for air brake system and its components. In addition, the effects of brake system failure are more critical for commercial vehicles which require more attention on their requirements details. Historically, the development of air brakes technology started on North America and Europe and consequently two strong and distinct resolutions were structured: FMVSS 121 and ECE R.13, respectively. For passenger cars were developed the ECER.13H to harmonize North American and European resolutions. However, for commercial vehicles regional applications, culture and implementation time must be considered. These commercial vehicles peculiarities must be understood and their specific requirements harmonized to attend the global marketing growth. This article shows a review of the North American and European air brake requirements and also discusses their influence on the South America considering technical vision as well as strategies for introduction of global technology. Additionally were compared ISO, SAE and ABNT standards focusing in opportunities to improve South American requirements to have more safety vehicles.
Iombriller, Silvia Faria, Bolognesi Prado, Wesley
Brake Adjustment Limit for Air Brake ActuatorsJ2899_201706 (Historical)6/9/2017
This SAE Recommended Practice applies to S-CAM, Wedge, and Disc air brake actuators where the stroke can be measured without disassembly from the brake.
Truck and Bus Brake Actuator Committee
Dimensional Specifications for Non-Metallic Body Push-to-Connect Fittings Used On a Vehicular Air Brake SystemJ2494/2_201706 (Current)6/7/2017
This SAE Standard covers general dimensional specifications for non-metallic body reusable push to connect tube fittings for use in the piping of air brake systems on automotive vehicles. This type of fitting is intended for use with nylon tubing per SAE J844. It is not intended to restrict or preclude other designs of a tube fitting for use with SAE J844. Performance requirements for SAE J844 are covered in SAE J1131. See SAE J2494-3 for the performance requirements of Reusable (push-to-connect) fittings intended for use in Automotive Air Brake Systems and U.S. Department of Transportation FMVSS 571.106.
Air Brake Tubing and Tube Ftg Committee
Performance Comparison between ABS 4S/4M and ABS 4S/3M2017-36-00015/24/2017
After the anti-skid brake system (ABS) introduction, mandatory for all vehicles in the Brazilian market, manufacturers have given increasing attention to optimized systems which meet legal and safety requirements. For commercial vehicles, an alternative for the ABS, which presents feasibility, is the configuration 4S/3M (4 wheel-speed sensors and 3 modulator valves) in substitution to the configuration 4S/4M. In other words, application of just one modulator valve to control the brakes of the same axle, front or rear, instead of independent control per each brake of the vehicle. The aim of this paper is to present a performance comparison between a brake system fitted with ABS configuration 4S/3M and an ABS configuration 4S/4M. To this end, both configurations were tested on the same vehicle application in accordance with the Brazilian legislation, CONTRAN 519/15. In addition, a test on which the vehicle was prepared with an unusual load distribution was performed in order to verify if the proposed system would be capable to keep its performance. A discussion regarding feasibility of ABS 4S/3M on 6x2 or 6x4 trucks is also presented.
de Souza, Luís Fernando Nuss, de Oliveira, Antônio Carlos, Vetter, Narã Vieira
Identification and Installation of Air Brake System ComponentsJ2580_201611 (Historical)11/1/2016
This Recommended Practice covers air braked trucks, truck-tractors, trailers and buses. It enumerates the identification and installation of the air brake components not covered in other SAE recommended practices and standards.
Truck and Bus Brake Systems Committee
Thread SealantsJ1615_201608 (Historical)8/16/2016
Male pipe threads, including male dryseal pipe threads, when made into assemblies or installed into ports, will generally leak if not covered with a sealant. This SAE Recommended Practice is intended as a guide to assist designers and/or users in the selection and application of various types of thread sealants. The designers and users must make a systematic review of each type and application and then select the sealant to fulfill the requirements of the application. The following are general guidelines and are not necessarily a complete list.
Air Brake Tubing and Tube Ftg Committee
Parking Brake Control Identification - Vehicles with Hydraulic Brake Systems and Automatic TransmissionsJ2688_201602 (Historical)2/18/2016
The scope and purpose of the SAE Recommended Practice is to provide standards for the control and indication of parking brakes in hydraulic braked vehicles over 4540 kg (10000 lb) GVWR. This recommended practice pertains to automatic transmission applications and supplements the SAE J915 recommended practice. This recommended practice does not address parking brake system performance. Parking brake system performance, both static and dynamic conditions, is the responsibility of the OEM vehicle manufacturer or manufacturers that modify the vehicle by adding special vocational required equipment (such as but not limited to outriggers, cranes, etc.).
Truck and Bus Hydraulic Brake Committee
Metallic Air Brake System Tubing and PipeJ1149_201510 (Current)10/21/2015
This SAE Standard covers minimum requirements for two types of metallic tubing and pipe as used in automotive air brake systems. It includes material and performance specifications, corrosion precautions, and installation recommendations. Copper tubing is designated Type 1, and galvanized steel pipe Type 2.
Air Brake Tubing and Tube Ftg Committee
Service Brake Structural Integrity Test Procedure - Vehicles Over 4500 kg (10 000 lb) GVWRJ294_201506 (Historical)6/12/2015
This SAE Recommended Practice establishes a method of testing the structural integrity of the brake system of all new trucks, buses, and combination vehicles designed for roadway use and falling in the following classifications: a Truck and Bus—Over 4500 kg (10 000 lb) GVWR b Combination vehicle—Towing vehicle over 4500 kg (10 000 lb) GVWR The test consists of two distinct tests: a Structural Endurance Test followed by a Structural Ultimate Strength Test. NOTE—These two tests originated from separate procedures, and were combined in this Recommended Practice. Each test can be considered to be an independent evaluation of the service brake’s structure. Based on time available, cost limitations, and the desired evaluation and historical data available, either of these tests could be considered as a complete evaluation of the brake’s structure.
Truck and Bus Foundation Brake Committee
Brakes Standards Interface Analysis Considering Brazilian, European and North American Regulations Focusing on Technologies Introduction2015-36-00275/13/2015
It is very important and unquestionable that we need to have a clear technical requirement for Air Brake Systems and its components, since it is one of most important regarding safety. Looking to heavy commercial vehicles and possible air brake system failures, everything becomes clearly to pay total attention for these normative and regulatory requirements. Historically, the development of Brakes technology has started on EUA and Europe and consequently two strong and distinct requirements were structured: FMVSS 121 and ECE-R13. From decades people are trying to harmonize these requirements and for passenger cars, the evolution was faster. However, for commercial vehicles there are more peculiarities considering regional applications and some of them cultural and implementation time. As globally market is growing so fast as well new markets around the world, become fundamental the clearly understanding of these similarities, variants, peculiarities and correlated requirements. This article shows a bibliographic and the North America and Europe requirement history also discussing the influence on the Brazilian commercial vehicles considering technical view as well strategies for last level of global technology introduction. Other historically fundamental bases for the development and validation of the brake system, such as ISO and SAE standards will also be addressed, considering its interface with auditing standards published by ABNT. It will show Brazilian scenario for searching improvements and development for new requirements and standards updating to reinforce Brazilian regulation (CONTRAN) bases focusing at vehicles safety.
Iombriller, Silvia F., Prado, Wesley B., Herrero, Claudio R.
Air Compressor Duty Cycle Reduction in Passenger Bus Application2015-01-01394/14/2015
Today urban buses are equipped with more air consuming devices for an example pneumatic doors, exhaust brake, air suspension and in SCR system to name a few. This has resulted in higher air demand leading to high compressor duty cycles which cause conditions (such as higher compressor head temperatures) that may adversely affect air brake charging system performance. These conditions may require additional maintenance due to a higher amount of oil vapor droplets being passed along into the air brake system. Factors that add to the duty cycle are air suspension, additional air accessories, use of an undersized compressor, frequent stops, excessive air leakage from fittings, connections, lines, chambers or valves, etc. This paper discussed about methodology used to reduce air consumption of air consuming devices used in urban bus application. Performance assessment of air consuming devices with minimum available air pressure was conducted and found satisfactory. Overall results as reduction in air compressor duty cycle.
Gangwar, Harish Kumar, Sharma, Ankur, Dabhole, Dipak, Prasad, Ambekar
Mathematical Model to Evaluate and Optimize the Dynamic Performance of Pneumatic Brake System2015-26-00821/14/2015
Pneumatic brake system is widely used in heavy truck, medium and heavy buses for its great superiority and braking performance over other brake systems. Pneumatic brake system consists of various valves such as Dual Brake Valve (DBV), Quick release Valve (QRV), Relay Valve (RV), Brake chambers. Dynamics of each valve is playing a crucial role in overall dynamic performance of the braking system. However, it is very difficult to find the contribution of each valve and pipe diameters in overall braking performance. Hence, it is very difficult to arrive a best combination for targeted braking performance as it is not possible to evaluate all combination on the actual vehicle. Hence, it is very important to have a mathematical model to optimize and evaluate the overall braking performance in early design phase. The present study is focusing on the mathematical model of a pneumatic brake circuit. The present model can be used in the design stage to finalize and optimize the Pneumatic brake system specifications. The vehicle level mathematical model has been created after validating component level model of each valves and system level model of brake system. The objective was to minimize cost as well as maximize the braking performance requirement as per IS11852 subjected to constraint such as pipe diameter, and difference between rise rate of pressure in the front and rear brake chambers. The results predicted by mathematical model was in very good correlation with the experimental results. Hence, the present mathematical model is used to freeze the braking system specification in the design phase itself.
Patil, Jeevan N., Palanivelu, Sivakumar, Aswar, Vaibhav, Sharma, Vipin
Brake Block Effectiveness RatingJ1802_201410 (Historical)10/27/2014
This SAE Recommended Practice provides the test procedure and methods to calculate the effectiveness of brake blocks, using an inertia dynamometer. To minimize testing variability, and to optimize standardization and correlation, a single, high volume size of brake block is specified (FMSI No. 4515E) and evaluated in a reference S-cam brake assembly of 419 mm x 178 mm (16.5 in x 7.0 in) size, using a specified brake drum.
Truck and Bus Foundation Brake Committee
A Pneumatic Hybrid System with an Integrated Compressor/Expander Unit for Commercial Vehicles2014-01-23709/30/2014
Braking energy recovery can significantly contribute to fuel economy and emission reduction, particularly for commercial vehicles driving in urban environment. By using the compressed air storage, rather than expensive and vulnerable batteries, this paper proposes a pneumatic hybrid system with an integrated compressor/expander unit (CEU) for commercial vehicles, in order to achieve stop/start function and braking energy recovery. During braking, the compressed air is recovered by CEU working in compressor mode and is charged to the air tanks. When the vehicle starts from stop, the CEU works as an expander to crank the engine with compressed air. The compressed air can also be used to supply the air tank of brake boost system, thus reducing its energy consumption. The mathematical models of energy conversion units, including the two modes of CEU and the air brake system, are established and analyzed. A preliminary case study of an urban bus application shows that, in an urban driving cycle, the compressed air recovered from braking is sufficient both for engine cranking and air brake system. Together with the achieved stop/start function of the pneumatic hybrid concept, the total fuel consumption can be reduced by 5.3%, compared to the conventional vehicle case.
Li, Daofei, Wang, Lei, Xu, Huanxiang, Fan, Zhipeng, Yu, Xiaoli
The Brake Pads Compensation Control Algorithm for Brake Force Distribution2014-01-22879/30/2014
A brake pad wear control algorithm used under non-emergency braking conditions is proposed to reduce the difference in brake pad wear between the front and rear axles caused by the difference in brakes and braking force. According to the adhesion state of the pad wear, the control algorithm adjusted the braking force distribution ratio of front and rear wheel that balanced adhesion pad wear value. Computer co-simulations of braking with Trucksim and Matlab/Simulink using vehicle models with equal brake pad wear, greater wear on the front axle and greater wear on the rear axle respectively is performed. The computation simulation results show that meet the brake force distribution system regulatory requirements and total vehicle braking force unchanged.
Zheng, Hongyu, Wang, Linlin
A Slip-Rate-Based Braking Force Distribution Algorithm for the Electronic Braking System of Combination Vehicle2014-01-23859/30/2014
The paper focus on enhancing the braking safety and improving the braking performance of the tractor/trailer vehicle. A slip-rate-based braking force distribution algorithm is proposed for the electronic braking system of tractor/trailer combination vehicle. The algorithm controls the slip-rates of the tractor's rear wheels and the semi-trailer's wheels changing with the slip-rate of tractor's front wheels, making tractor's front wheels lock up ahead of the tractor's rear wheels and the semi-trailer's wheels. The algorithm protects the combination vehicle from jackknifing and swing, guaranteeing that the combination vehicle has better driving stability and steering capability. The algorithm can be tested by co-simulation with MATLAB/Simulink and TruckSim software both on high adhesion and low adhesion roads. The simulation results shows that the algorithm can control the wheels' slip-rate changing in the settled range and shorten the braking time, thus improves braking performance of tractor/trailer combination vehicle.
Wang, Linlin, Zheng, Hongyu
Cost effective and Sustainable Alternate Material for Air Brake Tubings (ABT) in Commercial Vehicles2014-01-24099/30/2014
The automotive industry is constantly looking for new alternate material and cost is one of the major driving factors for selecting the right material. ABT is a safety critical part and care has to be taken while selecting the appropriate material. Polyamide (PA12) [1] is the commonly available material which is currently used for ABT applications. Availability and material cost is always a major concern for commercial vehicle industries. This paper presents the development of ABT with an alternative material which has superior heat resistance. Thermoplastic Elastomer Ether Ester Block Copolymer (TEEE) [3] materials were tried in place Polyamide 12 for many good reasons. The newly employed material has better elastic memory and improved resistance to battery acid, paints and solvents. It doesn't require plasticizer for extrusion process because of which it has got excellent long term flexibility and superior kink resistance over a period of time. Also it has got better heat ageing properties and higher burst pressure at elevated temperature. The development involves testing and characterization of the materials, making of prototypes and validations. Tubings were tested as per DIN 73378, DIN 74324 and ISO 7628 standards and found to meet the performance requirements. Approx. 20% cost savings is achieved through TEEE. This is one of the cost effective and sustainable solutions taken by Ashok Leyland Ltd and first of its kind in India.
Venkatesan, C, DeepaLakshmi, R
The Influence of Vacuum Booster Design Parameters on Brake Pedal Feel2014-01-24999/28/2014
Brake pedal feel characteristic is determined by the structural and kinetic parameters of the components of the brake system. As the servo power component of the brake system, vacuum booster has a significant influence on the brake pedal feel. In this paper, a brake system model for brake pedal feel which has a detail vacuum booster mathematical description is established in the software MATLAB/Simulink. The structure gaps, spring preload, friction force and reaction disc characteristics of vacuum booster are considered in this model. A brake pedal feel bench test under different input velocity and vacuum pressure is completed in order to validate the prediction of the model. Finally, based on the assessment index in pedal travel, pedal force and master cylinder pressure three-quadrant diagram, the influence of vacuum booster design parameters such as structure gaps, spring preloads, press plate and press ring areas, diaphragm effective area and reaction disc stiffness on the brake pedal feel characteristics is analyzed and discussed. This study can serve as important reference for vacuum booster design and adjustment.
Zhang, Lijun, Ruan, Cheng, Meng, Dejian
Technological Changes and Competitive Advantage: The New Deal for Avionics Firms2014-01-21739/16/2014
Since 2000, avionics is facing several changes, mostly driven by technological improvements in the electronics industry and innovation requirements from aircraft manufacturers. First, it has progressively lost its technological leadership over innovation processes. Second, the explosion of the electronics consumer industry has contributed to shorten even more its technology life cycles, and promoted the use of COTS. Third, the increasing complexity of avionics systems, which integrate more and more functions, have encouraged new players to enter the market. The aim of this article is to analyze how technological changes can affect the competitiveness of avionics firms. We refer to criticality levels as a determinant of the market competitiveness. Certification processes and costs could stop new comers to bring innovations from the consumer electronics industry and protects traditional players. The study will compare three avionics systems regarding their patent dynamics since 1980: flight controls, Integrated Modular avionics and Head-Up Displays. We assume that differences in the market competitiveness may appear due to their differences in their related criticality level. Systems belonging to Design Assurance Level A or B required wide-range of capabilities and long-term experience. The opportunity for new comers to introduce a certified-version of their product could be constrained by certification requirements.
Beaugency, Aurelie, Gatti, Marc, Regis, Didier
Modeling, Experimentation and Sensitivity Analysis of a Pneumatic Brake System in Commercial Vehicles2014-01-02954/1/2014
The main purpose of this research is to investigate the optimal design of pipeline diameter in an air brake system in order to reduce the response time for driving safety using DOE (Design of Experiment) method. To achieve this purpose, this paper presents the development and validation of a computer-aided analytical dynamic model of a pneumatic brake system in commercial vehicles. The brake system includes the subsystems for brake pedal, treadle valve, quick release valve, load sensing proportional valve and brake chamber, and the simulation models for individual components of the brake system are established within the multi-domain physical modeling software- AMESim based on the logic structure. An experimental test bench was set up by connecting each component with the nylon pipelines based on the actual layout of the 4×2 commercial vehicle air brake system. The experimental data of the transient pressure in both secondary and primary brake circuits was measured to verify the simulation accuracy and the positive results of the validation show a potential for investigating the most suitable parameter configuration of the pipeline diameter based on the computer-aided analytical dynamic models. A DOE process is then performed to determine the main factors which could greatly decrease the response time of the brake system. A remarkable improvement can therefore be obtained through altering each pipe diameter according to its direction of trend for the responses it has impact on.
Ma, Zeyu, Wu, Jinglai, Zhang, Yunqing, Jiang, Ming
Braking Force Distribution and Coordinated Control Algorithm for Hybrid Electric Bus based on EBS2014-01-19084/1/2014
In order to improve the braking energy recovery and ensure the braking comfort, a new type of regenerative braking coordinated control algorithm is designed in this paper. The hierarchical control theory is used to the regenerative braking control algorithm. First, the front axle braking force and rear axle braking force are distributed. Then the rear axle motor braking force and mechanical braking force are distributed. Finally, the dynamic coordinated control strategy is designed to control pneumatic braking system and motor braking system. Aimed at keeping the fluctuation of the total braking force of friction and the regenerative braking force small during braking modes switch, a coordinated controller was designed to control the pneumatic braking system to compensate the error of the motor braking force. Based on Matlab/Simulink platform, a parallel hybrid electric bus simulation model with electric braking system (EBS) was established. Then the simulation in different operating conditions was used to analyze the braking energy utilization and the braking performance based on the simulation model. Simulation results show that the proposed coordination regenerative braking control algorithm can effectively reduce the vehicle braking force error and improve the vehicle braking comfort. At the same time, the breaking energy recovered by the coordination regenerative braking control algorithm is nearly identical with the energy recovered by the biggest energy recovery control strategy.
He, Rong, Zheng, Hongyu, Zong, Changfu
Brake Adjustment Limit for Air Brake ActuatorsJ2899_201312 (Historical)12/17/2013
This SAE Recommended Practice applies to S-CAM, Wedge, and Disc air brake actuators where the stroke can be measured without disassembly from the brake.
Truck and Bus Brake Actuator Committee
ABS Development on a Vehicle with Air-Over-Hydraulic Brake System2013-36-024510/7/2013
The anti-lock brake system, known as ABS, whose the main function is to ensure directional stability and, consequently, the handling of the vehicle in an emergency brake application. Acting on the brakes, prevents the wheels are locked in extreme situations as well as in various applications on low friction floors. The most common applications found in our market are vehicles whose brakes are fully hydraulic or pneumatic. The purpose of this paper is to present all ABS development phases on an “air over hydraulic” vehicle, in other words, the front brake is acted by a hydraulic system and the rear by a pneumatic.
Junior, Getúlio Soares, Silva, Jean Cory de Souza, Pizzi, Rafael Fortuna, Guarenghi, Vinícius Mendes, Santarosa, Ricardo
Truck Tractor Power Output for Trailer ABSJ2247_201309 (Historical)9/5/2013
This SAE Recommended Practice identifies the minimum truck tractor electrical power output of the stop lamp and ABS (antilock brake system) circuits measured at the primary SAE J560 tractor trailer interface connector(s).
Truck and Bus Electrical Systems Committee
Automotive Air Brake Line Couplers (Gladhands)J318_201305 (Historical)5/28/2013
This SAE Recommended Practice is intended to provide design, interchangeable dimensions, testing procedures, performance requirements, and minimum identification for gladhand-type air line couplers used to connect the brake systems of trucks, truck-tractors, trailers, and dollies when these vehicles are joined to operate as a combination unit.
Truck and Bus Brake Supply and Control Components Committee
Contaminants for Testing Air Brake Components and Auxiliary Pneumatic Devices—Truck and BusJ2024_201305 (Historical)5/23/2013
This SAE Information Report establishes a minimum level of uniform recipes for contaminants which may be used when durability testing pneumatic components to obtain additional information on how a device may perform under more true-to-life operating conditions. This type of contamination testing, however, is not meant to replace the type of performance testing described in SAE J1409 and SAE J1410. Durability testing in the presence of contamination, however, will yield results more reflective of actual in-service field conditions and provide an additional evaluation of pneumatic devices. While the contaminant supply rate and other test criteria of the device being tested must be set by the device manufacturer or user, the items covered in this document will be:
Truck and Bus Brake Supply and Control Components Committee
Study on Braking Force Distribution Algorithm for Hybrid Electric Bus Based on EBS2013-01-04114/8/2013
In order to improve the braking energy recovery, a parallel hybrid electric bus simulation model with electric braking system (EBS) was established by co-simulation platform for the TruckSim and Matlab/Simulink in this paper. EBS makes the front and rear shaft braking force arbitrarily distributed, which is more effective to improve the rate of energy recovery and the braking stability. A braking force distribution algorithm for hybrid electric bus based on EBS was designed in this paper. Under the premise to meet the driver's needs and the ECE regulations, this braking force distribution method focuses on making the braking force distribute to the drive shaft to a maximum extent, so as to obtain the maximum energy recovery rate by the utilization of the motor regenerative braking. At last, the simulation in different operating conditions was used to analyze the braking energy utilization and the braking performance based on the simulation model. The simulation results show that the braking force distribution algorithm designed in this paper can improve the driving mileage and the fuel consumption can be significantly decreased.
He, Rong, Zheng, Hongyu, Zong, Changfu
An Approach to Vehicle Brake-By-Wire Optimal Control Tracking Strategy2013-01-06864/8/2013
In this paper, an optimal control tracking strategy for a brake-by-wire system is developed and tested on a laboratory setup consisting of a driving motor, clutch and gearbox system, rotating inertia and an electro-mechanical brake actuator. The presented brake by wire system consists of a brake pedal sub-system connected to the electro-mechanical brake actuator through an electronic control module handling the optimal control logic. A mathematical model of the proposed brake-by-wire control system is presented. The presented mathematical model is simulated and validated against the experimental data. The good agreement between both simulation results and experimental validates the mathematical model. The validated mathematical model is then used to test the proposed optimal control tracking strategy against different levels of disturbances that are difficult to emulate in the laboratory. The developed control logic ensures optimal control effort of the electro-mechanical brake actuator and, at the same time, efficient tracking between the brake pedal command and the braking deceleration profile. Consequently, the introduced logic plays a major role in keeping the tracking between the braking system command and its output as high as possible while not sacrificing the power supply (i.e. high drained electric current) in case of emergency situations. This provides acceptable braking performance while maximizing the system battery life and protects the brake actuator driver against high current.
Haggag, Salem A., Abidou, Diaa
Swell, Growth, and Dimensional Stability of Friction Materials and Noise Insulators when Exposed to Elevated TemperaturesJ160_201302 (Current)2/13/2013
This performance standard specifies a universal method of measuring the dimensional change of friction materials to determine the effects of temperature. The test applies to both, disc and drum type linings commonly used in hydraulic and air brake systems for automotive or commercial vehicle applications. This standard describes two main test procedures. Method A, where the friction material is in contact with a heated surface to simulate the heat input to the pad that occurs during actual usage. Method B uses an oven to heat the freestanding material and is an approximate procedure requiring less instrumentation. Method A is recommended for disc brake pad assemblies, noise insulators, or flat coupons; while Method B is recommended for curved drum brake linings.
Brake Linings Standards Committee
Connection and Accessory Locations for Towing Multiple Trailers - Truck and BusJ849_201301 (Current)1/4/2013
This SAE Recommended Practice establishes the recommended locations for the air brake and electrical connections for towing multiple trailers. It applies to all commercial trailers except drop frame and car haul types.
Truck and Bus Brake Supply and Control Components Committee
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