The assessment of brake friction materials extends beyond squeal noise and thermal roughness testing as it play crucial role in other brake noise phenomena such as creep groan and dynamic grunt. These low frequency noise types are significant as they directly affect passengers comfort levels. Creep groan noise defined as audible stick-slip noise at low vehicle speed during partial brake application, typically encountered in dense traffic conditions. Dynamic grunt is another form of stick-slip noise observed during high-speed braking and it is noticeable just prior to vehicle’s complete stop. This noise is indicative of frictional interaction between the brake pad and disc under deceleration scenario. Comparative analysis of two distinct brake friction materials was conducted utilizing both NVH dynamometer and real-world vehicle testing. The NVH dynamometer procedure was designed to evaluate the creep groan and dynamic grunt phenomena under controlled environmental conditions. For the

Barot, Ankit, Wang, Weicherng

Brake Heat Capacity Prediction Using a Machine-Learned Friction Coefficient Model and Virtual Wheel Brake

2024-01-3054

09/08/2024

Recently, the increasing complexity of systems and diverse customer demands have necessitated the development of highly efficient vehicles. The ability to accurately predict vehicle performance through simulation allows for the determination of design specifications before the construction of test vehicles, leading to reduced development schedules and costs. Therefore, detailed brake thermal performance predictions are required both for the front and rear brakes. Moreover, scenarios requiring validation, such as alpine conditions that apply braking severity to xEV with the regenerative braking system, have become increasingly diverse. To address this challenge, this study proposes a co-simulation method that incorporates a machine-learned brake pad friction coefficient prediction model to enhance the accuracy of brake thermal capacity predictions within the vehicle simulation environment. This innovative method allows for the simultaneous prediction of both front and rear-wheel brakes

Cho, Sunghyun, Baek, SangHeum, Kim, Min Soo, Hong, Incheol, Kim, Hyun Ki, Kim, Gwichul, Lee, Jounghee

CFD Methodology Development to Predict Lubrication Effectiveness in Electromechanical Actuators

2024-26-0466

06/01/2024

Electromechanical actuators (EMAs) play a crucial role in aircraft electrification, offering advantages in terms of aircraft-level weight, rigging and reliability compared to hydraulic actuators. For various functions within the actuator such as prevention of backdriving, torque limiting, damping, braking, etc., skewed roller devices are typically employed to provide braking torque. These technology components are continuing to be improved with analysis driven design innovations e.g., U.S. Pat. No. 8,393,568. The device has the rollers skewed around their own transverse axis that allow for a combination of rolling and sliding against the stator surfaces. This friction provides the necessary braking torque. By controlling the friction radius and analyzing the Hertzian contact stresses, the device can be sized for the desired duty cycle. While operating, the rollers require sufficient lubrication to ensure local temperatures do not exceed limits of the components or the lubricant itself

Bhardwaj, Divyanshu, Kumar, Anant, George, Jubin

Torque Vectoring for Lane-Changing Control during Steering Failures in Autonomous Commercial Vehicles

2024-01-2328

04/09/2024

Lane changing is an essential action in commercial vehicles to prevent collisions. However, steering system malfunctions significantly escalate the risk of head-on collisions. With the advancement of intelligent chassis control technologies, some autonomous commercial vehicles are now equipped with a four-wheel independent braking system. This article develops a lane-changing control strategy during steering failures using torque vectoring through brake allocation. The boundaries of lane-changing capabilities under different speeds via brake allocation are also investigated, offering valuable insights for driving safety during emergency evasions when the steering system fails. Firstly, a dual-track vehicle dynamics model is established, considering the non-linearity of the tires. A quintic polynomial approach is employed for lane-changing trajectory planning. Secondly, a hierarchical controller is designed. The upper layer employs a three-stage cascaded proportional integral controller

Lu, Ao, Li, Runfeng, Yinggang, Xu, Nie, Zexin, Li, Peilin, Tian, Guangyu

Innovative Zero-Emissions Braking System: Performance Analysis Through a Transient Braking Model

2024-01-2553

04/09/2024

This paper presents the analysis of an innovative braking system as an alternative and environmentally friendly solution to traditional automotive friction brakes. The idea arose from the need to eliminate emissions from the braking system of an electric vehicle: traditional brakes, in fact, produce dust emissions due to the wear of the pads. The innovative solution, called Zero-Emissions Driving System (ZEDS), is a system composed of an electric motor (in-wheel motor) and an innovative brake. The latter has a geometry such that it houses MagnetoRheological Fluid (MRF) inside it, which can change its viscous properties according to the magnetic field passing through it. It is thus an electro-actuated brake, capable of generating a magnetic field passing through the fluid and developing braking torque. A performance analysis obtained by a simulation model built on Matlab Simulink is proposed. The model is able to simulate the transient 1D motion of an electric vehicle equipped with four

Tempone, Giuseppe Pio, Imberti, Giovanni, de Carvalho Pinheiro, Henrique, Carello, Massimiliana

Experimental Comparison of Spark and Jet Ignition Engine Operation with Ammonia/Hydrogen Co-Fuelling

2024-01-2099

04/09/2024

Ammonia (NH3) is emerging as a potential fuel for longer range decarbonised heavy transport, predominantly due to favourable characteristics as an effective hydrogen carrier. This is despite generally unfavourable combustion and toxicity attributes, restricting end use to applications where robust health and safety protocols can always be upheld. In the currently reported work, a spark ignited thermodynamic single cylinder research engine was upgraded to include gaseous ammonia and hydrogen port injection fueling, with the aim of understanding maximum viable ammonia substitution ratios across the speed-load operating map. The work was conducted under stoichiometric conditions with the spark timing re-optimised for maximum brake torque at all stable logged sites. The experiments included industry standard measurements of combustion, performance and engine-out emissions. It was found possible to run the engine on pure ammonia at low engine speeds at low to moderate engine loads in a

Ambalakatte, Ajith, Cairns, Alasdair, Geng, Sikai, Varaei, Amirata, Hegab, Abdelrahman, Harrington, Anthony, Hall, Jonathan, Bassett, Michael

A Suspension Tuning Parameter Study for Brake Pulsation

2024-01-2319

04/09/2024

Brake pulsation is a low frequency vibration phenomenon in brake judder. In this study, a simulation approach has been developed to understand the physics behind brake pulsation employing a full vehicle dynamics CAE model. The full vehicle dynamic model was further studied to understand the impact of suspension tuning variation to brake pulsation performance. Brake torque variation (BTV) due to brake thickness variation from uneven rotor wear was represented mathematically in a sinusoidal form. The wheel assembly vibration from the brake torque variation is transmitted to driver interface points such as the seat track and the steering wheel. The steering wheel lateral acceleration at the 12 o’clock position, driver seat acceleration, and spindle fore-aft acceleration were reviewed to explore the physics of brake pulsation. It was found that the phase angle between the left and right brake torque generated a huge variation in brake pulsation performance. Multiple analyses have been run

Hong, Hyung-Joo, Lee, Changwook, Jun, Hyochan, Zhu, Dongzhe

Design, Modeling and Analysis of Customized Brake Caliper for SAE BAJA Vehicle

2023-01-5106

02/23/2024

All-terrain vehicles are gaining more popularity due to their off-roading nature. In this ATV one of the most important components which gives us a safe ride and control is the braking system. This study presents a detailed view of the design, modelling and analysis of brake caliper using Solidworks 2022 and Altair Hyperworks software for an all-terrain vehicle. A single piston floating caliper which is designed to fulfil conditions such as compact size to fit into wheel assembly, to provide adequate strength and great efficiency of about 80% during off-road conditions. This caliper is mainly designed to withstand a braking torque of 315645 Nm. The main aim of designing the caliper is to fit inside the wheel assembly of the ATV so that the interaction between the caliper is not with any other components. Furthermore, considerations are accounted as machinability are integrated into the design process, ensuring that the proposed brake caliper systems are performing well

Ravi Kumar, L., Prathiesh Lalan, R. A., Shriram Naibal, B., Chiranjeev Sanjay, P., Gananathji Naveen Kishore, S., Vasundharadevi, D.

Calibration of an Inertial Measurement Unit and Its Impact on Antilock Braking System Performance

2024-26-0014

01/16/2024

An Inertial Measurement Unit (IMU) provides vehicle acceleration that can be used in Active Vehicle Safety Systems (AVSSs). However, the signal output from an IMU is affected by changes in its position in the vehicle and alignment, which may lead to degradation in AVSS performance. Investigators have employed physics and data-based models for countering the impact of sensor misalignment, and the effects of gravity on acceleration measurements. While physics-based methods utilize parameters varying dynamically with vehicle motion, data-based methods require an extensive number of parameters making them computationally expensive. These factors make the above-explored methods practically challenging to implement on production vehicles. This study considers a 6-axis IMU and evaluates its impact on Antilock Braking System (ABS) performance by considering the IMU signal obtained with different mounting orientations, and positions on a Heavy Commercial Road Vehicle (HCRV). It then develops a

Dixit, Chitrartha, Gaurkar, Pavel, Ramakrishnan, Rajesh, Shankar Ram, C S, Vivekanandan, Gunasekaran, Sivaram, Sriram

Fault Compensation Control for Regenerative Braking of Distributed Drive Electric Vehicle Based on Hierarchical Control

2023-01-7061

12/20/2023

For distributed drive electric vehicles (DDEV) equipped with an electronic hydraulic braking system (EHB) and four-wheel hub motors, when one or more hub motors have regenerative braking failure, because the braking torque of the four wheels is inconsistent, additional yaw moment will be formed on the vehicle, resulting in the loss of directional stability of the vehicle during braking. If it occurs at high speeds, it will further threaten driving safety. To solve the above problems, a new hierarchical control architecture is established in this paper. Firstly, taking DDEV as the research object, the vehicle dynamics model and EHB braking system model are built. Then, a state observer based on an adaptive Kalman filter is designed in the upper layer to estimate the vehicle’s sideslip angle and yaw rate in real time. In the judgment decision-making layer, the phase plane is used to divide the stability domain boundary of the vehicle, and the quasi-stability tolerance band judges the

Fang, Ting, Zhao, Linfeng, Hu, Jinfang, Mei, Zhen, Wang, Muyun, Sun, Bin

Revolutionizing Electric Mobility: The Latest Breakthroughs in Tyre Design

2023-28-0056

11/10/2023

The increasing demand for electric mobility has brought about significant advancements in tyre design. This paper covers the latest developments in tyre design that cater specifically to the needs of electric vehicles (EVs). EVs have unique performance characteristics that place greater emphasis on tyre requirements like High traction, Wear resistance, Low Cavity & pattern noise, Low Rolling resistance and High load carrying capacity. Hence, the tyre manufacturers have been working relentlessly to create advanced designs that can meet these requirements. This paper will cover various aspects of tyre design, including tyre cavity, tread patterns, sidewall design, compound & reinforcement design, and various construction techniques. The tyre cavity and tread pattern play a crucial role in the overall performance of an EV. The new tyre cavity with flat tread and adaptive tread pattern are optimized to provide low rolling resistance, pattern noise reduction and enhanced dry and wet

Krishnakumar, Jeyakumar, Subbian, Jaiganesh, C S, Midhunkrishna

Brake Control Allocation Employing Vehicle Motion Feedback for Four-Wheel-Independent-Drive Vehicle

2023-01-1866

11/05/2023

This paper uses the brake control allocation method for Electric Vehicles (EVs) based on system-level vehicle Reference Point (RP) motion feedback. The RP motion control is an alternative to the standard brake torque allocation methods and results in improved vehicle stability in both longitudinal and lateral directions without requiring additional measurements beyond what is available in EVs with ABS and ESP. The proposed control law simplifies the brake torque allocation algorithm, reduces overall development time and effort, and merges most of the braking systems into one. Additionally, the measured or estimated signals required are reduced compared to the standard approach. The system-level RP measurements and references are transformed into individual wheel coordinate systems, where tracking is ensured by actuating both friction torques and electric motor regenerative torques using a proposed brake torque blending mechanism. The whole control system is validated in simulations

Vošahlík, David, Veselý, Tomáš, Hanis, Tomas, Pekar, Jaroslav

Applying Ferritic Nitrocarburizing (FNC) in Conjunction with Smart ONC® on GCI Brake Rotors: The New Generation of FNC Rotors to Meet the Euro 7 Standards

2023-01-1888

11/05/2023

As the regulations aiming to limit air pollution become stricter, the battle against non-exhaust emissions known to be harmful to human health and the environment is attracting more focus and extending worldwide. EVs are equipped with a hybrid braking system combining regenerative and hydraulic braking to provide the same performance as traditional vehicles. Whenever the regenerative braking torque is insufficient to give the necessary deceleration rate, the hydraulic and electromechanical braking torque is applied. Thus, the recuperative braking of EVs reduces the need for brakes. As the brakes are not used as often, dust and rust will accumulate and impede their performance, so brake problems can arise from not using them enough. Due to the extra weight of EVs compared to ICEVs, more particulates are released through increased corrosion and friction on the braking system. Grey cast iron brake rotors rust quickly, and excessive corrosion causes heavy damage to the rotor’s surface

Nousir, Saadia, Winter, Karl-Michael

TOC

99-05-04-0TOC

08/03/2023

TOC

Tobolski, Sue

A Mid-fidelity Model in the Loop Feasibility Study for Implementation of Regenerative Antilock Braking System in Electric Vehicles

10-07-03-0022

07/29/2023

The tailpipe zero-emission legislation has pushed the automotive industry toward more electrification. Regenerative braking is the capability of electric machines to provide brake torque. So far, the regenerative braking feature is primarily considered due to its effect on energy efficiency. However, using individual e-machines for each wheel makes it possible to apply the antilock braking function due to the fast torque-tracking characteristics of permanent magnet synchronous motors (PMSM). Due to its considerable cost reduction, in this article, a feasibility study is carried out to investigate if the ABS function can be done purely through regenerative braking using a mid-fidelity model-based approach. An uni-tire model of the vehicle with a surface-mount PMSM (SPMSM) model is used to verify the idea. The proposed ABS control system has a hierarchical structure containing a high-level longitudinal slip controller and a low-level SPMSM torque controller. Given the uncertainties of

Ghanami, Nastaran, Nikzadfar, Kamyar, Mohammadi Daniali, Hamid Reza

Inertia Calculation for Single-Ended Inertia-Dynamometer Testing

J2789_202304 (Current)

04/12/2023

This procedure provides methods to determine the appropriate inertia values for all passenger cars and light trucks up to 4540 kg of GVWR. For the same vehicle application and axle (front or rear), different tests sections or brake applications may use different inertia values to reflect the duty-cycle and loading conditions indicated on the specific test

Brake Dynamometer Standards Committee

Combined Path Following and Vehicle Stability Control using Model Predictive Control

2023-01-0645

04/11/2023

This paper presents an innovative combined control using Model Predictive Control (MPC) to enhance the stability of automated vehicles. It integrates path tracking and vehicle stability control into a single controller to satisfy both objectives. The stability enhancement is achieved by computing two expected yaw rates based on the steering wheel angle and on lateral acceleration into the MPC model. The vehicle's stability is determined by comparing the two reference yaw rates to the actual one. Thus, the MPC controller prioritises path tracking or vehicle stability by actively varying the cost function weights depending on the vehicle states. Using two industrial standard manoeuvres, i.e. moose test and double lane change, we demonstrate a significant improvement in path tracking and vehicle stability of the proposed MPC over eight benchmark controllers in the high-fidelity simulation environment. The numerous benchmark controllers use different path tracking and stability control

Lenssen, Daan, Bertipaglia, Alberto, Santafe, Felipe, Shyrokau, Barys

Mathematical formulation and Analysis of Brake Judder

2023-01-0148

04/11/2023

The Brake judder is a low-level vibration caused due to Disc Thickness Variation (DTV), Temperature, Brake Torque Variation (BTV), thermal degradation, hotspot etc. which is a major concern for the past decades in automobile manufacturers. To predict the judder performance, the modelling methods are proposed in terms of frequency and BTV respectively. In this study, a mathematical model is constructed by considering full brake assembly, tie rod, coupling rod, steering column, and steering wheel as a spring mass system for identifying judder frequency. Simulation is also performed to predict the occurrence of brake judder and those results are validated with theoretical results. Similarly, for calculating BTV a separate methodology is proposed in CAE and validated with experimental and theoretical results

S, Gurumoorthy, Bhumireddy, Yugandhar, Bourgeau, Alyssa, Bhimchand, Naresh

Compound Brake Control for Improved Ride Comfort for Dual-rotor In-wheel Motor Electric Vehicles

2023-01-0526

04/11/2023

Aiming at the problem of braking shock caused by the inconsistent response time of the inner motor (IM), the outer motor (OM) and the hydraulic brake when the regenerative braking mode of dual-rotor in-wheel motor (DRIWM) is switched, this paper proposes a U-shaped transition coordinated control strategy for the DRIWM. Ensure that the total braking torque can be smoothly transitioned when any one or more of the hydraulic braking torque, the braking torque of the IM and the braking torque of the OM enter/exit braking. The dynamic model of electric vehicle (EV) with DRIWMs is established, the division of braking mode is based on the principle of optimal DRIWM system efficiency, and the U-shaped transition coordinated controller of DRIWM is designed. Finally, two cases of switching the IM single braking mode to hydraulic braking mode and OM and hydraulic coordinated braking mode switching to compound braking mode are taken as examples to verify. The results show that, compared with the

leng, Fei, He, Ren

Research on Regenerative Braking Control Strategy of Commercial Vehicles Considering Battery Power Status

2023-01-0536

04/11/2023

Regenerative braking is an effective way to increase the cruising range of vehicles. In commercial vehicles with large vehicle mass, regenerative braking can be maintained in a high-power working state for a long time theoretically because of the large braking torque and long braking time. But in fact, it is often impossible to run at full power because of battery safety problems. In this paper, a control strategy is designed to maintain the maximum power operation of regenerative braking as much as possible. The maximum charging power of the battery is obtained through the battery model, and it is set as the battery limiting parameter. The regenerative braking torque and power are obtained by using the motor model. The eddy current retarder is used to absorb the excess power that the battery can't bear, and the braking torque of the eddy current retarder is calculated. Finally, mechanical braking is used to make up the insufficient braking torque. A set of algorithms is designed based

Xie, Beichen, Ding, Kangjie, Lin, Zhenmao

Driveline Control Influence when ABS Active

2023-01-0662

04/11/2023

The interaction between driveline control and anti-lock braking system (ABS) control in electric vehicles (EV) was investigated based on multi-body dynamics (MBD) model and control model co-simulation. Two primary driveline control algorithms, active damping control and wheel flare control, were integrated with ABS control in Simulink model and the influence on ABS control was studied. The event for high mu to low mu transition was simulated. When ABS control is active on low mu surface, the vehicle shows large wheel slip and long duration time before wheel speed returns to stable control. This performance could be improved with activating driveline control. Deceleration uniformity metric shows that active damping control has very small effect when ABS control becomes stable after passing through the high mu to low mu transition period. Driveline damping control can help to reduce vibration, but it is difficult to find satisfied tuning for wheel speed performance. Wheel flare control

Xing, Xing, Clark, Mark, Morris, Robert

Performance, Combustion and Emissions Evaluation of Liquid Phase Port-Injected LPG on a Single Cylinder Heavy-Duty Spark Ignited Engine

2023-01-0245

04/11/2023

Liquefied petroleum gas (LPG), like many other alternative fuels, has witnessed increased adoption in the last decade, and its use is projected to rise as stricter emissions regulations continue to be applied. However, much of its use is limited to dual fuel applications, gaseous phase injection, light-duty passenger vehicle applications, or scenarios that require conversion from gasoline engines. Therefore, to address these limitations and discover the most efficient means of harnessing its full potential, more research is required in the development of optimized fuel injection equipment for liquid port and direct injection, along with the implementation of advanced combustion strategies that will improve its thermal efficiency to the levels of conventional fuels. This paper focuses on the development of a liquid phase port-injection system for LPG, the design of a reference piston, and the baseline evaluation of the performance, combustion, and emissions characteristics of a single

Fosudo, Toluwalase, Kar, Tanmay, Windom, Bret, Schlagel, Jacob, Olsen, Daniel

Methodologic Assessment of Brake-by-Wire System Modelling with Regard to Accuracy, Model Complexity and Optimization Efforts

2023-01-0666

04/11/2023

Brake-by-wire systems are an innovative and important component of modern high-performance and also electrified vehicles. Due to their decoupled architecture, they enable driver-independent vehicle dynamics control (e.g., brake torque blending) and easy integration of assistance functionalities (e.g. Emergency Brake Assist (EBA)). On the other hand, the development of these functions can cause high costs and development effort, and testing can be critical in case of improper gain tuning. Therefore, already in the concept phase, a large part of the testing is shifted to virtual environments and simulations that allow safe and reproducible experiments without damage. Therefore, suitable and reliable models are needed to represent reality as accurately as possible. This paper deals with the modelling of a purely electrohydraulic brake-by-wire system and a hybrid system with electrohydraulic brakes on the front axle and electromechanical brakes on the rear axle. For comparison, both an

Heydrich, Marius, Kellner, Björn, Ivanov, Valentin

Effect of Standard Tuning Parameters on Mixture Homogeneity and Combustion Characteristics in a Hydrogen Direct Injection Engine

2023-01-0284

04/11/2023

Dihydrogen, as a zero CO2 fuel, is a strong candidate for internal combustion engine to limit global warming. This study shows the impact of standard tuning parameters on mixture homogeneity and combustion characteristics. A 2.2L Diesel engine on which the head was reworked to allow side mounted direct injector and central mounted spark plug was selected. The discussed tests were made at low engine speed and partial load. A spark advance sweep at different air-fuel ratios (λ) was conducted. The exponential relation between λ and NOx emissions is highly marked and extremely low NOx emissions up to 1.7 g/kWh at minimum spark advance for maximum brake torque can be measured. A λ sweep was performed at different starts of injection (SOI). The results show that, depending on the engine speed, a later SOI might lead to lower NOx emissions. For a λ setpoint of 1.8, at 1500 rpm, late SOI leads to 30% higher NOx emissions where at 2500 rpm these emissions are 26% lower. This assessment is

LOW-KAME, Jean, Oung, Richard, Meissonnier, Guillaume, Da Graca, Mathieu, Doradoux, Laurent, Foucher, Fabrice

Combined Physical and ANN-Based Engine Model of a Turbo-Charged DI Gasoline Engine with Variable Valve Timing

2023-01-0194

04/11/2023

High-efficient simulations are mandatory to manage the ever-increasing complexity of automotive powertrain system and reduce development time and costs. Integrating AI methods into the development process provides an ideal solution thanks to massive increase in computational power. Based on an 1D physical engine model of a turbo-charged direct injection gasoline engine with variable valve timing (VVT), a high-performance hybrid simulation model has been developed for increasing computing performance. The newly developed model is made of a physics-based low-pressure part including intake and exhaust peripheries and a neural-network-based high-pressure part for combustion chamber calculations. For the training and validation of the combustion chamber neural networks, a data set with 10.5 million operating points was generated in a short time thanks to the parallelizable combustion chamber simulations in stand-alone mode. The data set covers wide variation ranges of boundary and operating

Wei, Jingsi, Liu, Mingjia, Angerbauer, Michael, Yang, Qirui, Xu, Hanjun, Grill, Michael, Kulzer, André, Chen, Ceyuan

Applications of the Finite Element Analysis for Determination of Failure Safety Margins of the Design of the Honda CTX700 Motorcycle Front Braking System

05-16-03-0016

02/15/2023

The purpose of this article was to determine the failure safety margins of the front braking system of a Honda CTX700 motorcycle and to perform a substantive stress analysis on the system, as well as to verify the stresses using FEMAP. It should be noted that in this finite element analysis (FEA), the connections between components are modeled using linear-contact connections that exert forces on adjacent surfaces and are not trivially meshed as one solid with coincident grids with two different section material properties. The first part of the work involved accurately measuring the geometry of each part and three-dimensional (3D) modeling of all components. Measurements were taken via the trivial methods of using a ruler and caliper, and then the 3D model was generated in Solidworks by digitizing the geometric parameters. Some parts of the system were simplified in the 3D model to ensure proper meshing of the model. Cavities and complex geometries, like fillets and chamfers, were

Javidinejad, Amir, Orensztein, Hunter J., Ramirez, Marco, Berman, Jack

Brake Drum Qualification Recommended Practice

J2686_202212 (Current)

12/20/2022

This SAE Recommended Practice is intended for qualification testing for brake drums used on highway commercial vehicles with air brakes using an inertia-dynamometer procedure. This document consists of two distinct tests: Part A, durability and speed maintenance test, and Part B, heat check drag sequence test. Each test can be considered to be an independent evaluation of the brake drum which tests different properties

Truck and Bus Foundation Brake Committee

Aircraft Brake Quality Assurance Rejected Takeoff Test History and Considerations

AIR6417 (Current)

11/22/2022

This SAE Aerospace Information Report (AIR) provides information related to experience with carbon brake quality-assurance rejected takeoff tests, and considerations regarding test setup, test conditions, test frequency and cost considerations

A-5A Wheels, Brakes and Skid Controls Committee

Research on Regenerative Braking Control Strategy under High Charge State Using Prescribed Performance Prediction Control

2022-01-7041

10/28/2022

To reduce the energy consumption level of electric vehicles, the working range of the regenerative braking system will gradually expand to the high state of charge of the battery. The time delay in the control signal transmission path of the high state of charge regenerative braking control process will affect the regenerative braking. At the same time, regenerative braking under a high state of charge puts forward higher requirements for the control accuracy of regenerative current. In the research of this paper, the motor model, battery model, and vehicle dynamics model are firstly established by using MATLAB/Simulink, and the dynamic relationship between regenerative current and regenerative braking torque is analyzed at the same time. Considering the system time delay, this paper proposes a high-charge regenerative braking control strategy (SPPC) that combines Smith prediction and prescribed performance control. This control strategy can not only compensate for the system time

Sun, Dongsheng, Zhang, Junzhi, He, Chengkun, Ma, Ruihai

Drum and Disc Brake Static Performance Test Equivalency

J3192_202210 (Current)

10/13/2022

This SAE Recommended Practice is intended for measuring the static brake torque performance of a pnuematically actuated brake assembly, friction material, and drum/disc combination on an inertia brake dynamometer

Truck and Bus Brake Systems Committee

Brake Force Distribution Field Test Procedure for Truck and Bus

J225_202210 (Current)

10/07/2022

This SAE Recommended Practice provides a field test procedure and instructions for air braked single unit trucks, buses, and combination vehicles. Brake force distribution field testing with systems post-reduce stopping distance changes is still appropriate, however, vehicles with electronically controlled braking systems are not covered in this document and may need to be addressed in the future. It also provides recommendations for: a Instrumentation and equipment. b Vehicle preparation. c Test of air-braked single and combination vehicles. d Calculation of brake force distribution. e This test procedure is intended to be used as a field procedure. If a more refined method, utilizing laboratory equipment, is required, refer to SAE J1505

Truck and Bus Brake Systems Committee

Concept Design of a Parking Brake Module for Standstill Management and Wheel Individual Brake Torque Generation for EVs with Unconventional Service Brake Topology

2022-01-1186

09/19/2022

For electric vehicles the ability for regenerative braking reduces the use of friction brakes. Particularly on the rear axle of vehicles with reduced dynamic requirements such as urban vehicles, this can offer a potential for downsizing or, in extreme cases, even the elimination of the friction brakes on the rear axle. Due to the fact that the rear axle service brakes also represent the typical parking brake location in SoA (State-of-Art) vehicles, a rigorous rethinking of the parking brake concept is necessary to incorporate safe vehicle standstill management for such novel brake system topology. This research study introduces a novel parking brake design that covers SoA but also legal requirements while retaining potentials associated with the elimination of the rear service brakes such as cost and packaging. Also, the novel approach aims for a combination of traditional parking brake functionality and certain dynamic brake torques that are typically delivered by wheel individual

Loss, Tobias, Peter, Simon, Verhagen, Armin, Görges, Daniel

Enhancing Meta Model of the Brake Pad Friction Coefficient Using the Explainable Machine Learning

2022-01-1175

09/19/2022

Recently, increasing system complexity and various customer demands result in the need for highly efficient vehicle development processes. Once the brake torque is predicted accurately during the driving scenario in the earlier stage, it will be able to prevent the changing the vehicle or brake system design to satisfy the legal regulation and customer requirement. As brake torque performance target allocate brake pad friction coefficient level and characteristic, the accurate friction coefficient prediction should be preceded for accurate prediction for brake torque. Generally, the friction coefficient of the brake pad is known to vary nonlinearly depending on the physical properties of the disc and the pad, as well as the brake disc rotational speed, the disc temperature, and the hydraulic pressure. Furthermore, it varies depending on the driving scenario even when other conditions are the same. Therefore, it is necessary to apply new methods to solve these challenges. In this study

Cho, Sunghyun, Bang, Sunghoon, Jang, Jiwoo, Kim, Youngjae

Sizing Criteria for Stored Energy Systems Used for Emergency Braking

ARP6952 (Current)

05/24/2022

A-5A Wheels, Brakes and Skid Controls Committee

Research on Vehicle Rollover Warning and Braking Control System Based on Secondary Predictive Zero-Moment Point Position

2022-01-0916

03/29/2022

To solve the contradiction between model complexity and the warning accuracy of the algorithm of the vehicle rollover warning, a rollover state warning method based on the secondary predictive zero-moment point position for vehicles is proposed herein. Taking a sport utility vehicle(SUV) as the research object, a linear three-degrees-of-freedom vehicle rollover dynamics model is established. On the basis of the model, the lateral position of the zero-moment point and its primary and secondary rates of change are calculated. Then, the theoretical solution of time-to-rollover of the vehicles is deduced from the lateral position of the secondary predictive zero-moment point. When the rollover warning index, the lateral position of the zero-moment point, is greater than the set threshold, the active anti-rollover control system will be triggered. The active anti-rollover braking control system adopts a hierarchical control strategy. Taking the rollover warning index as the control target

Wang, Haiyang, Hou, Liming, Shangguan, Wen-Bin

Increasing the Effective AKI of Fuels Using Port Water Injection (Part II

2022-01-0434

03/29/2022

This is the second part of a study on using port water injection to quantifiably enhance the knock performance of fuels. In the United States, the metric used to quantify the anti-knock performance of fuels is Anti Knock Index (AKI), which is the average of Research Octane Number (RON) and Motor Octane Number (MON). Fuels with higher AKI are expected to have better knock mitigating properties, enabling the engine to run closer to Maximum Brake Torque (MBT) spark timing in the knock limited region. The work done in part I of the study related increased knock tolerance due to water injection to increased fuel AKI, thus establishing an ‘effective AKI’ due to water injection. This paper builds upon the work done in part I of the study by repeating a part of the test matrix with Primary Reference Fuels (PRFs), with iso-octane (PRF100) as the reference fuel and lower PRFs used to match its performance with the help of port water injection. Additionally, the unburned gas pressure-temperature

Gopujkar, Siddharth, Worm, Jeremy, Barros, Sam, Bonfochi Vinhaes, Vinicius, Hansley, William

Combustion Phasing Indicators for Optimized Spark Timing Settings for Methane-Hydrogen Powered Small Size Engines

2022-01-0603

03/29/2022

In the intermediate stage towards zero-emissions, use of methane-hydrogen blends in spark ignition (SI) engines could represent an attractive application. The present work investigated the relevance of empirical base rules for choosing maximum brake torque spark timing settings when using methane-hydrogen blends. A 0D/1D model was used for investigating the optimized ignition for maximizing engine output. Calibration was performed by using in-cylinder pressure data recorded on a methane fueled small size SI engine for two-wheel applications. After adaptations of the model such as valves timing, for rendering it more representative for power generation applications, the investigation was focused on how MBT spark advance was correlated to the 50% mass fraction burned mark (CA50) and peak pressure location. The fact that they were optimized for methane was found to be essential only for high concentrations of hydrogen. Engine speed instead was found to exert an important influence on the

Irimescu, Adrian, Cecere, Giovanni, Sementa, Paolo

Aircraft Tire History

AIR5487B (Current)

02/11/2022

This SAE Aerospace Information Report (AIR), is intended to provide a continuum on historical development of aircraft tires

A-5C Aircraft Tires Committee

Influence analysis of brake linings roughness on static friction coefficient between brake linings and shoes

2021-36-0428

02/10/2022

The static coefficient of friction between lining and shoe plays a fundamental role in the lining fixing project, which is the most important parameter for the riveted joint calculation. For the lining riveting, the rivet needs to ensure that friction material and shoe remain in contact through the normal force applied on the surfaces, but the rivet should not be exposed to shear forces. Thus, the brake torque transmission must occur through the static coefficient of friction between lining and shoe, not allowing relative slips or movements between the pair in contact. Therefore, the present study aims to understand the influence of the static friction coefficient between lining and shoe as a function of the lining internal superficial roughness, from the evaluation of different roughness conditions - contact area with shoe -. The static coefficient of friction between lining and shoe is a complex measurement to be performed, due to the cylindrical geometry of the drum brake system, so

Antunes, Diego Severo, Brezolin, André, Favero, Juliana, Wille, Norton Hernandez, Bastos, Saulo Renê Casarin, Luza, Thaysa

Influence of friction material and brake system strain on the brake air chamber total stroke

2021-36-0433

02/10/2022

The braking capacity of reducing the speed or even keeping the vehicle stoped is extremely important in the design of any brake system, as more than meeting legislation requirements; it directly affects the safe operation of the vehicle and its users. A fundamental component, which requires notable attention, is the friction material, which is designed to establish a compromise between mechanical properties, friction coefficient, noise propensity, deformation, wear, among others. However, braking capacity is a combined response for several of these friction material properties, along with the performance of other brake system components, such as the brake chamber, disc and caliper. This work aims to analyze firstly the influence of the friction material deformation and secondly the brake system deformation on the total stroke of the brake chamber. To the first one, three different formulations of friction material, applied to commercial vehicles, were selected. For these materials

Santos, Roger Lusa, Amaral, Everton P., Antunes, Diego S., Favero, Juliana, Garbuio, Mateus A., Lazzari, Mauricio, Luciano, M, Neis, Patric D., Ferreira, Ney

Comparison Of Performance In Vehicle Braking With Active And Inactive ABS System

2021-36-0072

02/04/2022

The invention of the wheel was an important milestone in the history of mankind. With it was possible to significantly reduce the friction between an object and the ground, requiring less force to move them and making it possible to transport items of interest. The use of the wheel in vehicles brought great advantages, however, it became necessary to control the speed, to avoid accidents with the environment around it. As a result, there was a need for the development of brake systems. The main function of the brake system is the transmission of the braking torque to the wheels, through the conversion of kinetic energy into heat. However, conventional brake systems had a serious problem with the car's ability to control while braking. The ability to control the vehicle, known as handling, is dependent on the adhesion between the tire and the ground. Driving loss occurs when the wheels lock during braking. To solve this problem, the Antilock Brake System (ABS) was created, an active

Fiorentin, Thiago Antonio, De Borba, Thiago

Combustion Performance of Methane Fermentation Gas with Hydrogen Addition under Various Ignition Timings

2022-32-0043

01/09/2022

Hydrogen (H2) addition is widely used for natural gas combustion to improve the engine efficiency. However, less attention was paid on the various ignition timings for the maximum brake torque (MBT) and brake thermal efficiency (BTE). In order to check the ignition timing effect, experiments were performed in a spark ignition engine with engine speed fixed on 1500 revolutions per minute (rpm). Firstly, CH4 was only used for combustion with excess air ratio (λ) changing from 0.8 to 1.4. Then, co-combustion of 50 vol% CH4 and 50 vol% CO2 was checked to simulate methane fermentation gas. Finally, H2 was added with volume percentage varying from 5% to 20%. Among these discussions, torque, brake mean effective pressure (BMEP), BTE and cylinder pressure were evaluated. Based on the results, high efficiency can be achieved by advancing the ignition timing with H2 addition at λ=1.4. However, with H2 addition, the ignition timing should be retarded to obtain higher BTE. At the lean-burn

Luo, Hongliang, Jin, Yu, An, Yanzhao, Matsumura, Yukihiko, Ichikawa, Takayuki, Kim, Wookyung, Nakashimada, Yutaka, Nishida, Keiya

Analysis of the Effect of the Wedged Type Brake Caliper Piston on Brake Drag

2021-01-1293

10/11/2021

Recently, there’s a massive flow of change in the automotive industry with the coming era of electric vehicles and self-driving (autonomous) vehicles. The automotive braking system field is not an exception for the change and there are not only lots of new systems being developed but also demands for researches for optimizations of conventional brake systems fitting to the newly appeared systems such as E-Booster and Electric Motor Brake (EMB) Caliper. Taking the Electric Motor Brake Caliper for example, it is considered as a very important and useful system for autonomous vehicles because the motor actuator of the caliper is much easier to control with ECUs compared to the conventional hydraulic pressure system. However, easy of control is not the only thing that excites brake system engineers. Since the whole actuating mechanism of the brake systems has been changed, engineers now can see some new ways to solve chronic problems in conventional brake systems such as brake residual

Kim, Yooho, Kwon, Taiksang, Lee, Soonwook

Systems of Automatic Brake Torque Reduction on the Wheels of One Axle of the Car

2021-01-126610/11/2021

Braking mechanisms have the most variation in performance of all of the elements of the braking system. Instability of braking torques on the wheels of one axle of the vehicle leads to the appearance of the braking forces unevenness, and then- to the vehicle skidding during braking. At one time, the appearance of open-type disc brakes made it possible to reduce the unevenness of the braking forces on the sides of the car due to their higher characteristics of energy intensity and stability. However, the lack of feedback between the left and right disc brakes mounted on the same axle of the vehicle does not allow reducing the unevenness of the braking forces to an acceptable minimum. The authors of the work studied and proposed several systems for automatic reduction of the braking torques unevenness for braking mechanisms mounted on the wheels of one axle

Podrigalo, Mikhail, Kholodov, Mykhailo, Stepanov, Victor, Soloviov, Oleh, Aleksandrov, Yevgeniy, Volontsevych, Dmytro, Morozov, Oleksandr

Potential and Challenges for Application-Specific Friction Characteristics of Race Brake Pads

2021-01-128210/11/2021

As a race driver hits the pedal to trigger the braking event, a dynamic load transfer takes place in the car. This is a similar kind of weight transfer experienced on the road while stopping any vehicle abruptly. Modern race cars such as FIA-regulated Grand Touring Car classes GT3 and LMGTE produce a significant aerodynamic downforce at a reasonably high efficiency level. In this type of high downforce race cars, load variations originated by aerodynamics are added onto the mass transfer. The combination of these effects provide a braking effect with this type of cars a highly transient character. At the same time, our customers are facing the challenge of strict technical regulations, usually forbidding brake control systems. In motorsport competition, car performance is of primary priority to help our customers win championships. For the pursue of maximum performance, it is essential to make use all available load on each tyre in order to stop later, by optimizing braking efficiency

Ugarte, Xabier, Voigt, Juergen

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