Browse Topic: Brake pedals

Items (197)

Model Based NVH Simulator for Virtual Development

2025-01-005905/05/2023

For mature virtual development, enlarging coverage of performances and driving conditions comparable with physical prototype is important. The subjective evaluation on various driving conditions to find abnormal or nonlinear phenomenon as well as objective evaluation becomes indispensable even in virtual development stage. From the previous research, the road noise had been successfully predicted and replayed from the synthesis of system models. In this study, model based NVH simulator dedicated to virtual development have been implemented. At first, in addition to road noise, motor noise was predicted from experimental models such as blocked force and transfer function of motor, mount and body according to various vehicle conditions such as speed and torque. Next, to convert driver’s inputs such as acceleration and brake pedal, mode selection button and steering wheel to vehicle condition, 1-D performance model was generated and calibrated. Finally, the audio and visual feedback

Park, Sangyoung, Dirickx, Tom, Kang, Yeon June, Nam, Jeong Min

Brake Line Repair: An Evaluation

2022-01-100103/29/2022

Brake line failures do occur, and it can happen to any vehicle. However, due to the FMVSS requirements, the brake line systems are also designed to maintain certain braking capability in the event of a brake line failure. This study was intended to further understand the effects of a brake line failure and examine the braking capability and controllability of the vehicle. A minivan was used as the test vehicle for this research. One of the brake lines of the minivan was cut and then reconnected with a compression fitting. When the compression fitting is not fully tightened, it will allow brake fluid leakage, and in the tests, the brake fluid was completely drained to simulate the empty brake fluid reservoir by repeatedly pushing the brake pedal. After the test vehicle lost all the brake fluid, braking tests were conducted. The stopping distance and the tire marks on the ground were documented. The test results show contrary to the unfounded myth that a brake line failure will result in

Arnett, Michael, Chen, H. Fred, Guenther, Dennis

DESIGN OF LOAD CELL OPERATED MAGNETIC BRAKING SYSTEM

2022-01-110603/29/2022

The traditional braking system uses hydraulic fluid with components such as master cylinder, floating calliper, brake pedal, and connecting rod. The disadvantage with this system is regular maintenance, changing of oil and leakage. To overcome these disadvantages and making it cost effective this work is proposing a Load-cell operated magnetic braking system. It is reliable and requires less maintenance. The braking process involves impressing load on the load cell installed upon the steering wheel of the car. The load is converted to electric signals and will be transferred to the amplifier, then this amplified signal is supplied to hub of the rotor which is magnetic operated and applies brake. This braking system has more safety and accuracy compared to traditional braking system. Brakes are disengaged magnetically and engaged electrically. This brake system is used for dynamic stopping and holding halt and has flexibility in controlling the braking force through voltage applied

Srivastava, Jay Prakash

Evaluating Simulation Driver Model Performance using Dynamometer Test Criteria

2022-01-063803/29/2022

The influence of driver modeling and drive cycle target speed trace modification on vehicle dynamics within energy consumption simulations is studied. EPA dynamometer speed error criteria and the SAE J2951 standard are applied to simulation outputs as proposed components of simulation validation, providing guidelines for acceptable vehicle speed outputs and allowing comparison of simulation results to reported EPA dynamometer test statistics. The combined effect of driver model tuning and drive cycle interpolation methods is investigated for the UDDS, HwFET and US06 drive cycles, with EPA-specified linearly interpolated speed trace and PI controller driver as a baseline result. Additional benefits of driver tuning are presented including a reduction in unnecessarily-aggressive simulated accelerator and brake pedal actuation, resulting in a 50% or greater drop in simulated vehicle RMS jerk and peak jerk in each analyzed case compared to baseline. For the simulated vehicle, a “lazy

Legg, Thomas, Nelson, Douglas

IMPROVEMENT IN THE BRAKE PEDAL FEEL COMFORT FOR LIGHT COMMERCIAL VEHICLES WITH HYDRAULIC BRAKE SYSTEM

2021-26-051509/22/2021

Being a safety critical aggregate, every aspect of brake system is considered significant in vehicles operations. Along with optimum performance of brake system in terms of deceleration generation, brake pedal feel or brake feel is considered as one of the key elements while evaluating brake system of vehicles. There are many factors such as liner and drum condition, road surface, friction between linkages which impress the pedal feel. Out of these, in this paper we will be discussing the factors which influence the brake pedal feel in relation to the driver comfort and confidence building. Under optimum braking condition, brake operation must be completed with pedal effort not very less or not very high, brake pedal feel must be firm throughout the operation, in such a way that it will not create fatigue and at the same time it will give enough confidence to the driver while operating with acceptable travel. These aspects are considered while evaluating the brake system performance in

Pujari, Sachin Subhashrao, Pandey, Prashant, Nagrikar, Ravi, Babel, Prashant, Charugundla, Sai Chaitanya

Service Maintenance of SAE J1703 and SAE J1704 Brake Fluids in Motor Vehicle Brake Systems

J1707_202106 (Current)

06/10/2021

This SAE Recommended Practice provides basic recommendations for dispensing and handling of SAE J1703 and SAE J1704 Brake Fluids by Service Maintenance Personnel to assure their safe and effective performance when installed in or added to motor vehicle hydraulic brake actuating systems. This document is concerned only with brake fluid and those system parts in contact with it. It describes general maintenance procedures that constitute good practice and that should be employed to help assure a properly functioning brake system. Recommendations that promote safety are emphasized. Specific step-by-step service instructions for brake maintenance on individual makes or models are neither intended nor implied. For these, one should consult the vehicle manufacturer’s service brake maintenance procedures for the particular vehicle. Vehicle manufacturer’s recommendations should always be followed.

Brake Fluids Standards Committee

Low Water Tolerant Brake Fluids

J1705_202105 (Current)

05/28/2021

This SAE Recommended Practice was prepared to provide engineers, designers, and manufacturers of motor vehicles with a set of minimum performance requirements in order to assess the suitability of silicone and other low water tolerant type brake fluids (LWTFs) for use in motor vehicle brake systems. These fluids are designed for use in braking systems fitted with rubber cups and seals made from styrene-butadiene rubber (SBR), or a terpolymer of ethylene, propylene, and a diene (EPDM). In the development of the recommended requirements and test procedures contained herein, it is concluded that the LWTFs must be functionally compatible with braking systems designed for SAE J1703 and SAE J1704 fluids. To utilize LWTFs to the fullest advantage, they should not be mixed with other brake fluids. Inadvertent mixtures of LWTFs with fluids meeting SAE J1703 are not known to have any adverse effects on performance, but not all combinations have been tested. Vehicle manufacturer’s recommendations

Brake Fluids Standards Committee

Low Water Tolerant Brake Fluids

J1705_202105-TEST-REC (Historical)05/28/2021

This SAE Recommended Practice was prepared to provide engineers, designers, and manufacturers of motor vehicles with a set of minimum performance requirements in order to assess the suitability of silicone and other low water tolerant type brake fluids (LWTFs) for use in motor vehicle brake systems. These fluids are designed for use in braking systems fitted with rubber cups and seals made from styrene-butadiene rubber (SBR), or a terpolymer of ethylene, propylene, and a diene (EPDM). In the development of the recommended requirements and test procedures contained herein, it is concluded that the LWTFs must be functionally compatible with braking systems designed for SAE J1703 and SAE J1704 fluids. To utilize LWTFs to the fullest advantage, they should not be mixed with other brake fluids. Inadvertent mixtures of LWTFs with fluids meeting SAE J1703 are not known to have any adverse effects on performance, but not all combinations have been tested. Vehicle manufacturer’s recommendations

Brake Fluids Standards Committee

Research on Compensation Redundancy Control for Basic Force Boosting Failure of Electro-Booster Brake System

2020-01-021604/14/2020

As a new brake-by-wire solution, the electro-booster (Ebooster) brake system can work with the electronic stability program (ESP) equipped in the real vehicle to realize various excellent functions such as basic force boosting (BFB), active braking and energy recovery, which is promoting the development of smart vehicles. Among them, the BFB is the function of Ebooster's servo force to assist the driver's brake pedal force establishing high-intensity braking pressure. After the BFB function failure of the Ebooster, it was not possible to provide sufficient brake pressure for the driver's normal braking, and eventually led to traffic accidents. In this paper, a compensation redundancy control strategy based on ESP is proposed for the BFB failure of the self-designed Ebooster. Firstly, introduced the working principle of Ebooster and ESP, and a suitable pressure-building circuit was selected for the dual brake actuator system; Secondly, after the BFB failure of Ebooster, the rule-based

Zhao, Jian, Chen, Zhicheng, Zhu, Bing, Wu, Jian

Vehicle accelerator and brake pedal on-off state judgment by using speed recognition

2020-01-137704/14/2020

The development of intelligent transportation improves road efficiency, reduces automobile energy consumption and improves driving safety. The core of intelligent transportation is the two-way information interaction between vehicles and road environment. At present, mainly the road environment information transmits to vehicles, while the information of vehicles rarely transmits to the outside. The electronic throttle and electronic braking systems of some vehicles using sensors to get the state of the accelerator and brake pedal, which can be transmitted to the outside through technologies such as the Internet of vehicles. But, Internet of vehicles technology has not been widely used, and it relies on signal sources, which is a passive way of information acquisition. In this paper, an active identification method is proposed to get vehicle pedal on-off state also driver operation behavior through existing traffic facilities. The research object is commercial vehicles driving on

Tian, Zhongpeng, Yang, Bo, linpeng, Cong, Zhou, Fangyu, Tan, Gangfeng

2020 Corvette Stingray: beautiful - and beautifully imperfect

20AUTP04_1204/01/2020

Grasping the true beauty of Chevy's new 2020 Corvette supercar demands a deep dig. You must venture beyond the exciting-to-a-fault sheetmetal and the lavish stitched-leather, buffed-metal, and carbon-fiber-embellished interior. You have to look past the revolutionary powertrain and chassis engineering. Nor will you discover the 2020 Corvette's place in the cosmos by summing up its performance stats. In fact, beyond the major improvement in acceleration from rest (0-60 mph [97 km/h] easily cracking the 3-sec. barrier), several indices - curb weight, Cg height, polar moment of inertia, drag coefficient and frontal area - have moved in the wrong direction. In the end, driving this car is the only means of gauging the leap the Corvette engineers have achieved with their rejuvenation of “America's sports car.”

Regressions of brake pads compressibility from experimental data

2019-36-001401/13/2020

One of the critical characteristics in a brake pad is its deformation when subjected to compressive loads. This deformation is called compressibility, which can be obtained quantitatively through compression cycles performed by a specific test bench. However, such testing is costly and long enough not to meet the demand of manufacturers of friction materials. To overcome this difficulty, this work presents regressions for the estimation of compressibility through the natural frequencies of the pads, since they can be obtained quickly and at low cost through a simple modal analysis. The theoretical basis for the correlation between compressibility and natural frequencies includes the theory of elasticity - which defines an inverse relationship between strain and stiffness - and the theory of vibrations, which defines the natural frequencies of a mechanical system as a function of its mass matrices and stiffness. Since the dependent variable (compressibility) and explanatory variable

Suetti, André Garcia Lima

Commercial vehicle pedal feeling comfort ranges definition

2019-36-001601/13/2020

The brake pedal is the brake system component that the driver fundamentally has contact and through its action wait the response of the whole system. Each OEM defines during vehicle conceptualization the behavior of brake pedal that characterizes the pedal feel that in general reflects not only the characteristic from that vehicle but also from the entire brand. Technically, the term known as Pedal Feel means the relation between the force applied on the pedal, the pedal travel and the deceleration achieved by the vehicle. Such relation curves are also analyzed in conjunction with objective analysis sheets where the vehicle brake behavior is analyzed in test track considering different deceleration conditions, force and pedal travel. On technical literature, it is possible to find some data and studies considering the hydraulic brakes behavior. However, for pneumatic brake systems, the pedal feel theoretical study is not usual, where is normally used for these developments, exclusively

Bolognesi Prado, Wesley, Faria Iombriller, Silvia, Rodrigues da Silva, Marco André, Renato Oliveira, Lázaro

Influence of Pads and Brake Disc wear on Brake Squeal Noise

2019-36-000501/13/2020

The present work aims to investigate the influence of wear of the pads and brake disc on the brake squeal behavior with the help of the Finite Element tool. Brake discs basically work by the pressure of the brake pads against a rotating disc. The friction between the pads and the disc causes the latter to decelerate, but it can also cause dynamic instabilities of the system giving rise to noises. Among the main noise in vehicle brake systems, there is the squeal noise, which is usually associated with the coupling of two neighboring natural modes. One possible way to identify unstable modes is by extracting complex eigenvalues from the system. An unstable mode can be identified when, in the result of the extraction of the complex eigenvalues, the real part of the eigenvalue is positive. In the present work, a brake system (disc and positioned pads and their respective materials and friction coefficients) was duly modeled and validated. The validation was done by means of a correlation

dos Anjos, Marco Túlio Batista, Gutiérrez, Juan Carlos Horta, Ferreto, Cláudio Junior, Silva, Felipe Dornellas, Donadon, Lázaro Valentin

Brake Pedal Feeling Comfort Analysis for Trucks with Pneumatic Brake System

2019-01-214009/15/2019

The brake pedal is the brake system component that the driver fundamentally has contact and through its action wait the response of the whole system. Each OEM defines during vehicle conceptualization the behavior of brake pedal that characterizes the pedal feel that in general reflects not only the characteristic from that vehicle but also from the entire brand. Technically, the term known as Pedal Feel means the relation between the force applied on the pedal, the pedal travel and the deceleration achieved by the vehicle. Such relation curves are also analyzed in conjunction with objective analysis sheets where the vehicle brake behavior is analyzed in test track considering different deceleration conditions, force and pedal travel. On technical literature, it is possible to find some data and studies considering the hydraulic brakes behavior. However, for pneumatic brake systems, the pedal feel theoretical study is not usual, where is normally used for these developments, exclusively

Bolognesi Prado, Wesley, Iombriller, Silvia Faria, Silva, Marco Andre, Oliveira, Lázaro Renato

EDITORIAL: There is no substitute for ‘Automotive Grade’

19AUTP09_0509/01/2019

When you get in a vehicle and push the ‘start’ button, you're betting that the machine will get you to your destination safely and reliably, regardless of the driving conditions. Lives are at stake the moment you lift off the brake pedal. A high level of reliability and a supremely robust useful life are what separate Automotive Grade products from mere consumer-grade stuff. The old “10 years and 100,000 miles” design bogey long used in vehicle development is now 15 years and 150,000 miles, and it's become the design-life baseline for everything from camshafts to cameras. Engineering new electrical, electronic, and mechanical components and systems to automotive-level thermal extremes (−40C to 125C) is second only to meeting military-grade (−55C to 125C) spec.

Brooke, Lindsay

Development of Parametrically Integrated Software Platform for Passenger Car Brake System

2019-01-123104/02/2019

The hydraulic servo brake system for passenger car plays a central role in occupant protection, which directly affects the automotive active safety and road handling. In this paper, an integrated parameterized software platform of hydraulic servo brake systems is proposed to realize fast and efficient braking system development. At first, according to the structure and working principle of the hydraulic servo brake system, the relationship among amount of fluid required for brake caliper, pedal feel and performance of the brake system is analyzed. Then, based on kinematics and dynamics of the hydraulic servo brake system, a simulation model for analyze pedal feel and amount of fluid required for brake caliper is built in AMESim, which is composed of brake pedal, vacuum booster, brake master cylinder, brake hoses and brake calipers, etc. In addition, the accuracy of the simulation model is verified by bench tests, and the significantly influential factors on the amount of fluid required

Pan, Jin, Guo, Xuexun, Zhou, Wei, Pei, Xiaofei, Pan, Hao, Zhang, Jie

Optimized Braking System Sizing by Means of a Parametric 1D Brake Model

2019-26-035501/09/2019

This paper presents a methodology that incorporates a 1D (non-geometric) brake model, together with conventional vehicle tests, into the solution of problems associated with the sizing of a braking system. The 1D tool is aimed at predicting the main braking attributes, such as pedal feel or thermal capacity under repeated snubs, and the fulfilment of the legislative requirements -service, emergency and parking brake performance. The model recreates a parametric brake system, and thus allows engineers to understand the impact a parameter (e.g. a specification) might have on the overall performance when it is altered. This calculation provides valuable assistance when sizing a braking system. The methodology presented succeeds in reducing the number of vehicle test iterations throughout the brake sizing stage, thus being more cost-effective and less time-consuming than the usual trial and error approach to select the off-the-shelf components available from suppliers.

Molina Montasell, Narcís, Santosh, Raunak

Reducing Brake Steer Which Causes Vehicle Drift during Braking

2019-26-007201/09/2019

Brake steer is an undesirable phenomenon where a vehicle deviates to one side of the road during braking. Vehicle deviation i.e. drift causes driver discomfort, where a driver has to constantly apply Steering Wheel corrections while braking in order to safely maintain the desired path. In a particular model of commercial vehicle segment, an issue of unacceptable right-side vehicle drift during braking was observed which was making the drive of the vehicle unsafe for the driver. Aim of this paper is to analyse the probable causes of such a vehicle drift, to objectively measure actual vehicle drift during braking using a unique methodology. In this paper, the root cause of the brake steer is discussed and an improvement on the vehicle is proposed by changing kinematic hard points of suspension and steering linkage to reduce the brake steer to the limit that vehicle drift is almost eliminated, and vehicle becomes completely safe for the driver to drive. Multibody Simulation (MBD) is

Gupta, Anshul, Ghosh, Brindaban, Balasubramanian, A, Patil, Sudhir, Raval, Chetan

High-Preload Deflection and Compressibility Test Procedures for Friction Materials

J2468_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

Compressible Brake Fluid Turbulent Flow Simulation and Experimental Verification on Brake Bleeding Performance Improvements of an EPB Caliper

2018-01-187610/05/2018

Brake bleeding is the process of removing air bubbles present on hydraulic brake systems from the master cylinder to the calipers of a vehicle, including the brake pipes and hoses. This is very important procedure affecting on brake performance, but still has been a key issue in automobile industry for last decades because reaching best bleeding performance has a limit that there is always remaining air in brake system. In this paper, it is reported on numerical and experimental investigations into the topic of bleeding performance improvements. Compressible brake fluid turbulent flow simulation with two-phase mixture model was performed to investigate the details of the bleeding performance drop during its cycles. The rig test of the hollow cylinder was carried out in order to secure the brake consumption amount curve whose results were used for the criterion of the parametric simulations using Tait equation to estimate the property of the brake fluid with the bulk modulus of 19,535

Design Optimization of the Disc Brake for Squeal Noise Reduction

2018-01-187410/05/2018

In this paper, squeal noise reduction method of the disc brake was proposed. And, its effectiveness was described. Pad motion was studied with pad abutment types comparison. The brake design was optimized by using the design of experiment method. The effectiveness of the optimum design was clarified by the noise tests with a dynamometer.

Correlation of Objective and Subjective Evaluation in Automotive Brake Pedal Feel

2018-01-188910/05/2018

In order to establish the correlation between objective and subjective evaluation of brake pedal feel for passenger cars, road tests of brake pedal feel were carried out and an evaluation method was proposed. In the road tests, subjective scores and objective measurements were obtained under the conditions of uniform and emergency braking. The objective measurements include pedal preload, low deceleration pedal force and travel, moderate deceleration pedal force and travel, brake response time and brake linearity. Using the theory of analytic hierarchy process (AHP), the design process of the evaluation method was established. Key setups including the hierarchical structure model, the judgement matrix and the score calculation method of objective measurements were described in detail. Then, the correlation between subjective and objective scores was analyzed. It can be concluded that the evaluation method is effective and it can be applied to brake pedal feel assessment and adjustment.

Zhang, Jingyi, Meng, Dejian, Liu, Jialin

Mass-cutting innovations bask in Altair recognition

18AUTP09_0609/01/2018

Employing a mixed-material strategy that includes the latest advanced high-strength steels (AHSS) and shedding 450 lb (205 kg) compared to its predecessor are major reasons why the 2019 Chevrolet Silverado was chosen as the Full Vehicle category winner of the 6th annual Altair Enlighten Awards, presented by Altair and the Center for Automotive Research (CAR) at the Management Briefing Seminars (MBS) in Traverse City, Mich. The Silverado was among six winners in four categories to be recognized for their mass-reduction achievements. In the Module category, BMW won with its 3D-printed metal convertible roof bracket used in the 2018 i8 roadster, a claimed industry first for a production series vehicle. The Enabling Technology category honored three innovations: Asahi Kasei's brake pedal bracket for the Mazda MX-5 that was designed using glass-fiber-reinforced polyamide 66 (GFRP); Sika Automotive's lightweight constrained layer material system for structure-borne noise damping; and United

Truck Brake Failure: Differences between Failure Modes for Drum and Disc Brakes

2018-01-052804/03/2018

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.

Combined Hill Descent Braking Strategy for Heavy Truck in the Featured-Slope

2017-01-253509/17/2017

The continuous braking for the brake drum will cause the brake thermal decay when the heavy truck is driving down the long slope in the mountain areas. It reduces the heavy truck’s braking performance and the braking safety. The engine braking and the hydraulic retarder braking both consume the kinetic energy of the heavy truck and can assist the truck driving in the mountain areas. This research proposes a combined hill descent braking strategy for heavy truck based on the recorded information of the slopes to ensure the braking safety of the heavy truck. The vehicle dynamic model and the brake drum temperature rising model are established to analyze the drum’s temperature variation during the downhill progress of the heavy truck. Then based on the slope information, the combined braking temperature variation is analyzed considering the characteristics of the engine braking, the drum braking and the hydraulic retarder braking. The research result shows that the brake drum’s

Xu, Yongbing, Mei, Binyu, Xiao, Longjie, XIA, Wanyang, Tan, Gangfeng

Estimation of Brake Friction Coefficient for Blending Function of Base Braking Control

2017-01-252009/17/2017

The brake architecture of hybrid and full electric vehicle includes the distinctive function of brake blending. Known approaches draw upon the maximum energy recuperation strategy and neglect the operation mode of friction brakes. Within this framework, an efficient control of the blending functions is demanded to compensate external disturbances induced by unpredictable variations of the pad disc friction coefficient. In addition, the control demand distribution between the conventional frictional brake system and the electric motors can incur failures that compromise the frictional braking performance and safety. However, deviation of friction coefficient value given in controller from actual one can induce undesirable deterioration of brake control functions. The main objective of the presented study is to propose a method to compensate disturbances induced by variations of brake linings friction coefficient through modifications of the brake torque demand for the enhancement of

Ricciardi, Vincenzo, Savitski, Dzmitry, Augsburg, Klaus, Ivanov, Valentin

Wear, Friction and NVH Characterization Using a Laboratory-Scale Tribometer

2017-36-000305/24/2017

The current study presents some testing procedures which have been designed for friction and noise measurements of brake friction materials using a laboratory-scale tribometer. The uncertainties (errors) and precision of the measurements are also described in this paper. Some case studies related to friction, wear and noise related issues in brake friction materials were chosen to show the respective testing procedures. Through the error study, it was shown that the uncertainties of the lab. test bench are mainly associated with 3 variables: torque, force and sliding radius. The combined uncertainty of the friction measurements is less than or equal to ±1%, considering the typical operating range of the machine. The possibility of using two samples from a single brake pad also contributes to the reliability of the machine test and procedures. Finally, the laboratory-scale tribometer and testing procedures discussed in the present paper proved to be adequate to characterize friction

Pavlak, Rafael Paini, Neis, Patric Daniel, Poletto, Jean Carlos, de Barros, Liu Yesukai, Ferreira, Ney Francisco

Modeling, Simulation and Experimental Analysis of Brake Pedal Feel for Passenger Car

2017-01-137103/28/2017

Brake pedal feel plays an important role in the driver's comprehensive subjective feeling when braking, which directly affects the active safety and riding comfort of passenger car. A systematical mathematical model of the vehicle brake system is built in according with the structure and system characteristics of hydraulic servo brake system. A complete hydraulic servo brake system simulation model composed of brake pedal, vacuum booster, brake master cylinder, brake pipe, brake wheel cylinders, brake calipers is established in AMESim. The effects of rubber reaction plate stiffness, rubber valve opening, brake master cylinder piston, brake caliper, brake pipe deformation and friction liner deformation on brake pedal feel are considered in this model. The accuracy of this model is verified by real road vehicle tests under static and dynamic two different conditions. The influence of six structural parameters of vacuum booster, brake pipe and brake caliper on brake pedal feel are

Pan, Hao, Guo, Xuexun, Pei, Xiaofei, Dong, Xingzhi

Use of Electric Driveline for a Cooperative Braking Strategy

2017-01-159503/28/2017

This paper presents a brake control strategy with a novel approach to the allocation of actuator effort in an electric vehicle. The proposed strategy relies on a combination of the conventional hydraulic braking system and the electric machine in order to improve braking performance. The higher response frequency of the electric machine is paired with the additional braking torque employed by the hydraulic brakes using an integrated control allocation strategy, which allows for a constant availability of a faster and more accurate modulation of both wheel torque and wheel speed. Therefore, the availability of an electric machine as a fast longitudinal actuator yields to an improved tracking of the desired wheel slip, especially when compared to the hydraulic actuators used in traditional braking applications. As a result, this strategy leads to a clear and considerable reduction of the braking distance, removes the need for a hydraulic modulator and thereby also removes the disturbing

Arat, Mustafa Ali, Duringhof, Hans-Martin, Hagnander, Johan, L. Simoes, Eduardo

Vibro-Impact Analysis of Manual Transmission Gear Rattle and Its Sound Quality Evaluation

2017-01-040303/28/2017

Experimental schemes, frequency characteristics, subjective and objective sound quality evaluation and sound quality prediction model establishment of a certain mass-production SUV (Sport Utility Vehicle, SUV) manual transmission gear rattle phenomenon were analyzed in this paper. Firstly, vehicle experiments, including experiment conditions, vibration acceleration sensor and microphone arrangements and especial considerations in experiments, were described in detail. Secondly, through time-frequency analysis, broadband characteristics of manual transmission gear rattle noise were identified and vibro-impact of gear rattle occurs in the frequency range of 450~4000Hz on the vehicle idle condition and the creeping condition. Thirdly, based on bandwidth filtering processing of gear rattle noise, subjective assessment experiments by a paired comparison method were carried out. Evaluation results passed triangular loop verification and Spearman correlation coefficient examination, and then

Wu, Guangqiang, Wu, Huwei

Development of Advanced Braking System for Hybrid Sports Cars

2016-01-192309/18/2016

An advanced braking system had to be developed for a next-generation hybrid sports car with Sport Hybrid Super Handling All-Wheel Drive to achieve an intuitive brake feeling in a variety of driving conditions, ultimate track performance and reduction of CO2 emissions per vehicle. This paper outlines the integration of brake-by-wire with traditional high-performance braking hardware and describes the technology needed to achieve these goals. Key focus areas to generate these results were: brake feeling control, corner hardware specification considerations and brake cooling.

Dyar, Lorne R., Akita, Yuichiro, Paul, Scott, Lepito, Joseph, Ishikawa, Yoshio, Watanabe, Tomohiro

Service Maintenance of SAE J1703 and J1704 Brake Fluids in Motor Vehicle Brake Systems

J1707_201609 (Historical)

09/13/2016

This SAE Recommended Practice provides basic recommendations for dispensing and handling of SAE J1703 and SAE J1704 Brake Fluids by Service Maintenance Personnel to assure their safe and effective performance when installed in or added to motor vehicle hydraulic brake actuating systems. This document is concerned only with brake fluid and those system parts in contact with it. It describes general maintenance procedures that constitute good practice and that should be employed to help assure a properly functioning brake system. Recommendations that promote safety are emphasized. Specific step-by-step service instructions for brake maintenance on individual makes or models are neither intended nor implied. For these, one should consult the vehicle manufacturer’s service brake maintenance procedures for the particular vehicle. Vehicle manufacturer’s recommendations should always be followed.

Brake Fluids Standards Committee

The Wagging Foot of Uncertainty: Data Collection and Reduction Methods for Examining Foot Pedal Behavior in Naturalistic Driving

2016-01-152604/05/2016

Pedal misapplications may be rare, but the outcomes can be tragic. A naturalistic driving study with 30 drivers was conducted to gain a better understanding of foot pedal behaviors. Foot movements were observed from the moment subjects entered and positioned themselves in their vehicle, and continued through starting the ignition, shifting into gear, accelerating to driving speed, and finally, resting their foot after parking the vehicle. A coding methodology was developed to categorize the various foot movements and behaviors. Over 3,300 startup and parking sequences were coded. This paper describes the unique challenges involved in classifying foot movements and behaviors when drivers’ intentions are not known. For example, hesitant or interrupted foot movements often occurred when a driver was transitioning from a gas pedal press to a brake pedal press. Such behaviors required definitions beyond what might be typically considered a “pedal error” (e.g., pressing the wrong pedal, or

Ng Boyle, Linda, Wu, Yuqing, Ebe, Kazutoshi, Foley, James, Angell, Linda, McGehee, Daniel V., Roe, Cheryl A.

Study of Muscle Activation of Driver’s Lower Extremity at the Collision Moment

2016-01-148704/05/2016

At the collision moment, a driver’s lower extremity will be in different foot position, which leads to the different posture of the lower extremity with various muscle activations. These will affect the driver’s injury during collision, so it is necessary to investigate further. A simulated collision scene was constructed, and 20 participants (10 male and 10 female) were recruited for the test in a driving simulator. The braking posture and muscle activation of eight major muscles of driver’s lower extremity (both legs) were measured. The muscle activations in different postures were then analyzed. At the collision moment, the right leg was possible to be on the brake (male, 40%; female, 45%), in the air (male, 27.5%; female, 37.5%) or even on the accelerator (male, 25%; female, 12.5%). The left leg was on the floor all along. Muscle activation of gastrocnemius, vastus medialis and vastus lateralis of right legs of male drivers in brake pedal region were significantly larger compared

Gao, Zhenhai, Li, Chuzhao, Hu, Hongyu, Chen, Chaoyang, Zhao, Hui, Yu, Helen

Development of an Electronically Controlled Brake System for Fuel-efficient Vehicles

2016-01-166404/05/2016

To solve various environmental problems, fuel-efficient vehicles that reduce CO2 emissions as well as exhaust gas emissions have been developed. In such vehicles, a regenerative brake is used to further reduce fuel consumption. Because the market size for such vehicles is expanding, a brake system is required that can be used in a wide range of vehicles extending from internal combustion engine vehicles (ICEVs) to electric vehicles (EVs). In addition, issues such as deceleration fluctuation and brake pedal fluctuation arise because the regenerative brake force is dependent on the vehicle speed. This paper presents a brake system configuration and its element technologies that can replace existing brake systems in different vehicles ranging from ICEVs to EVs. The proposed system can realize a regenerative cooperative brake not only by replacing the brake booster unit but also without replacing the modulator. The advantages of this system are the maximization of regenerative efficiency

Masuda, Yoshio, Yamasoe, Yosuke, Kuki, Yosuke, Okano, Takahiro, Uchida, Kiyoyuki

Investigation and Reduction of Brake Squeal and Groan Noise

2015-01-268709/27/2015

Brake noise is one of the common complaints and an irritant not just for the vehicle occupants but equally for the passers-by. Brake noise is actually vibration that is occurring at a frequency that is audible to the human ear. This occurrence of brake noise like brake squeal (>1 kHz) and groan (<1 kHz) is often very intense and can lead to vehicle complaints. During a brake noise event, vehicle basic structure and suspension system components are excited due to brake system vibration and result in a resonance that is perceived in the form of a noise. Proposed work discusses an experimental study that is carried out on a vehicle for addressing concern regarding disc brake squeal and groan noise. Based on the preliminary inputs, vehicle level study was carried out in order to simulate the problem and objectively capture its severity. During the process major influencing factors like hydraulic brake pressure, vehicle speed, brake temperature etc. have been monitored and varied across

Choudhary, Aditya Kant, Mense, Yogesh, Singh, Saurabh, Shridhare, Mahesh

Unpowered Exoskeleton Aids Walking

06/01/2015

Hardware-in-the-loop Simulation for an Integrated Braking System

2015-01-158204/14/2015

Comparing with traditional braking systems of automobiles, the brake-by-wire (BBW) system has a faster dynamic response and is more suitable for applications that facilitate regenerative braking. As the two main categories of BBW systems, the well-known electro-hydraulic braking system and electro- mechanical braking system are not compact enough and their fail-safe function has always been a worrying aspect. A new BBW system called integrated braking system (IBS) by employing the hydraulic multiplex method was proposed in recent years. The IBS implements power-assisted braking and active braking by means of just an integrated unit. It can certainly be used for ABS, ASR and ESC systems for building up and reducing brake pressure. Presented in the paper is a new structure of IBS, which is mainly composed of a motor, ball screw, master cylinder and four 2/2-way valves. The main parameters of the system and performance requirements of the motor are determined by means of simulation in

Yong, Jiawang, Gao, Feng, Ding, Nenggen, Wang, Wei, Hu, Xianrong

Ergonomic Guidelines for Carts and Dollies

USCAR41 (Current)03/13/2015

This document describes the assessment methods and physical requirements associated with the manual handling of carts and dollies, specific to material handling systems. All possible designs and applications could not be anticipated in creating these guidelines. Where there are questions of adherence to this document, such as use of an “off-the shelf” design, always consult the responsible Ergonomics Department. Force guidelines were primarily developed referencing the push/pull psychophysical Snook data contained in A Guide to Manual Materials Handling (second edition) by Mital, Nicholson and Ayoub (NY: Taylor & Francis, 1997). The force guidelines accommodate 75% of female capabilities and 99% of male capabilities. Factors that were included in the established guideline include: push / pull distances, vertical hand height, horizontal hand height, frequency and wheel / castor alignment and load rating. These factors were used to develop a conservative force guideline. The guidelines

The Brake Pads Compensation Control Algorithm for Brake Force Distribution

2014-01-228709/30/2014

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

ASURT Formula Student Brake Design

2014-01-248709/28/2014

The Braking System is the most crucial part of the racing vehicle. There is no doubt, that if only one minority failure in the braking system took place, this would be more than enough reason to cause the racing team disqualification from the competition. Time is the main and the most important criteria for any racing competition; on the other hand the formula student “FS UK SAE” competition care the most about developing the automotive engineering sense in the students by putting them under strict rules normally taken from the original version “formula 1” to encourage their creativity to reach the optimum performance under these strict rules. One of the most important rules is “No Braking by wire”, and the obvious consequences are more stopping distance and time. Braking distance is a critical facture in achieving racing success in a competitive domain. This report will cover using the bias bar, dynamic weight distribution “before and after braking” and carefully choosing the braking

Barakat, Mohamed Samy

The Influence of Vacuum Booster Design Parameters on Brake Pedal Feel

2014-01-249909/28/2014

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

Zhang, Lijun, Ruan, Cheng, Meng, Dejian

Innovative Concept of Front Disc Brake Module with Weight Reduction and Cost Optimisation

2014-01-250509/28/2014

The customer satisfaction index is higher for disc brake systems because of the advantages like less reaction time, shorter stopping distance and improved pedal feel compared to drum brake system. In current competitive market scenario and as per customer requirements, front disc brake module is becoming necessary. The brake system design is challenging task due to stringent performance meeting criteria and packaging constraints with weight optimization. Brake disc is very important component in the brake system which is expected to withstand high braking torque and dissipate heat during braking event. In existing car to replace front drum brake with disc brake module, vehicle needs to undergo legislative verifications and certifications with respect to pedal effort, stopping distance and circuit failed conditions etc. This paper explains development of disc brake system with novel brake disc during transition to switch from drum to disc brake with respect to packaging constraints

Shah, Ashesh, Patil, Sanjay, Abhyankar, Umesh

Evaluation of Creep Groan Phenomena of Brake Pad Materials Using Different Abrasive Particles

2014-01-251809/28/2014

Creep groan is a low-frequency (20-300Hz) self-excited brake vibration caused by stick-slip phenomena at the friction interface observed at very low vehicle speed. The creep groan propensity of friction materials is closely related with the difference (Δμ) between the static (μs) and the kinetic (μk) coefficients of friction. In this study, a NAO brake pad material was used as a base formulation and the abrasives tested were commercial grade of black iron oxide, chromite, zirconium oxide, magnesium oxide and aluminum oxide. Experimental results were obtained by testing seven different friction material formulations, in which the type of abrasives or its hardness or its particle size was changed in order to explore the impact of these variables on the stick-slip occurrence. A laboratory-scale tribometer was used to investigate the influence of different types of abrasives and their physical properties in the stick-slip. The results showed that abrasive particle size and hardness

Masotti, Diego, Ferreira, Ney, Neis, Patric, Menetrier, Ademir, Matozo, Luciano, Varante, Paulo

A Study on Modeling of Driver's Braking Action to Avoid Rear-End Collision with Time Delay Neural Network

2014-01-020104/01/2014

Collision avoidance systems for rear-end collisions have been researched and developed. It is necessary to activate collision warnings and automatic braking systems with appropriate timing determined by a monitoring system of a driver's braking action. Although there are various systems to monitor driving behavior, this study aims to create a monitoring system using a driver model. This study was intended to construct a model of a driver's braking action with the Time Delay Neural Network (TDNN). An experimental scenario focuses on rear-end collisions on a highway, such as the driver of a host vehicle controlling the brake to avoid a collision into a leading vehicle in a stationary condition caused by a traffic jam. In order to examine the accuracy of the TDNN model, this study used four parameters: the number of learning, the number of neurons in the hidden layer, the sampling time with 0.01 second as a minimum value, and the number of the delay time. In addition, this study made a

Hirose, Toshiya, Gokan, Masato, Kasuga, Nobuyo, Sawada, Toichi

Combination of Test with Simulation Analysis of Brake Groan Phenomenon

2014-01-086904/01/2014

During a car launch, the driving torque from driveline acts on brake disk, and may lead the pad to slip against the disk. Especially with slow brake pedal release, there is still brake torque applies on the disk, which will retard the rotation of disk, and under certain conditions, the disk and pad may stick again, so the reciprocated stick and slip can induce the noise and vibration, which can be transmitted to a passenger by both tactile and aural paths, this phenomenon is defined as brake groan. In this paper, we propose a nonlinear dynamics model of brake for bidirectional, and with 7 Degrees of Freedom (DOFs), and phase locus and Lyapunov Second Method are utilized to study the mechanism of groan. Time-frequency analysis method then is adopted to analyze the simulation results, meanwhile a test car is operated under corresponding conditions, and the test signals are sampled and then processed to acquire the features. Finally, the results of the simulation and those of the test are

Wu, Guangqiang, Jin, Shuyi

Modeling, Experimentation and Sensitivity Analysis of a Pneumatic Brake System in Commercial Vehicles

2014-01-029504/01/2014

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

Ma, Zeyu, Wu, Jinglai, Zhang, Yunqing, Jiang, Ming

Operator Controls on Industrial Equipment

J297_201307 (Current)07/09/2013

This SAE Standard is intended to improve operator efficiency and convenience by providing guidelines for the uniformity of location and direction of motion of operator controls used on industrial wheeled equipment. The controls covered are those centrally located at the operator's normal position.

HFTC1, Controls, Visibility, Anthropometrics, Accessibility

Determination of Brake Fluid Temperature

J291_201304 (Current)04/09/2013

This code provides a test procedure for obtaining and determining extremely high brake fluid temperature encountered in the brake system of a vehicle that is equipped with disc brakes. Vehicles in normal operation may or may not produce brake fluid temperatures that are obtained in this procedure.

Road Test Procedures Standards Committee

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