Browse Topic: Braking systems

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Quantitative Analysis of a Hybrid Electric HMMWV for Fuel Economy Improvement2024-01-335604/23/2025
ABSTRACT This paper presents a quantitative analysis and comparison of fuel economy and performance of a series hybrid electric HMMWV (High Mobility Multi-purpose Wheeled Vehicle) military vehicle with a conventional HMMWV of equivalent size. Hybrid vehicle powertrains show improved fuel economy gains due to optimized engine operation and regenerative braking. In this paper, a methodology is presented by which the fuel economy gains due to optimized engine are isolated from the fuel economy gains due to regenerative braking. Validated vehicle models as well as data collected on test tracks are used in the quantitative analysis. The regenerative braking of the hybrid HMMWV is analyzed in terms of efficiency from the kinetic energy at the wheels to the portion of regenerative power which is retrievable by the battery. The engine operation of both the series hybrid and conventional HMMWV are analyzed using a 2-D bin analysis methodology. Finally, the vehicle model is used to make
Nedungadi, Ashok, Masrur, Abul, Khalil, Gus
Technical Paper
Test JSW2-6715 NewJSW26715_202501 (Current)01/17/2025
testing
Ground Vehicle European Prospect Committee
Technical Standard
NASA’s Inspection Technology for Spacecraft Tests Quality of Seacraft HullsTBMG-5222312/05/2024
Shipbuilders didn’t have the option of fiberglass when the nonprofit American Bureau of Shipping (ABS) was established 160 years ago to help safeguard life and property on the seas. Fortunately, technology to help better ensure the safety of ocean vessels has also come a long way in that time, in part because people have become a spacefaring species.
Magazine Article
Quantitative Analysis of a Hybrid Electric HMMWV for Fuel Economy Improvement2024-01-3356-TEST-REC11/15/2024
ABSTRACT This paper presents a quantitative analysis and comparison of fuel economy and performance of a series hybrid electric HMMWV (High Mobility Multi-purpose Wheeled Vehicle) military vehicle with a conventional HMMWV of equivalent size. Hybrid vehicle powertrains show improved fuel economy gains due to optimized engine operation and regenerative braking. In this paper, a methodology is presented by which the fuel economy gains due to optimized engine are isolated from the fuel economy gains due to regenerative braking. Validated vehicle models as well as data collected on test tracks are used in the quantitative analysis. The regenerative braking of the hybrid HMMWV is analyzed in terms of efficiency from the kinetic energy at the wheels to the portion of regenerative power which is retrievable by the battery. The engine operation of both the series hybrid and conventional HMMWV are analyzed using a 2-D bin analysis methodology. Finally, the vehicle model is used to make
Nedungadi, Ashok, Masrur, Abul, Khalil, Gus
Technical Paper
Experimental Study on Quality Control and Variable Valve Timing Strategy of Hydrogen Engine for High Efficiency and Low Emission at Low Load2024-01-509510/15/2024
In order to reduce the pumping loss of low loads and maximize the lean combustion advantage of hydrogen, the paper proposes a load control strategy based on hydrogen mass, called quality control, for improving thermal efficiency and emissions at low loads. The advantages of quality control and the effect of VVT on the combustion performance of hydrogen internal combustion engines under low loads were discussed. The results show that when the relative air–fuel ratio (λ) increases to more than 2.5, the NOx emissions are reduced to less than 3.5 g/kW · h at the brake mean effective pressure (BMEP) below 8 bar, especially when the BMEP is less than 5 bar, the NOx is within 0.2 g/kW · h. Compared to quantity control based on air mass, the quality control strategy based on hydrogen mass achieves over a 2.0% reduction in pumping loss at BMEP levels lower than 4.4 bar. Furthermore, it enhances thermal efficiency by up to 5% at low loads, while maintaining NOx emissions within 0.2 g/kW · h at
Li, Yong, Chen, Hong, Fu, Zhen, Du, Jiakun, Wu, Weilong
Technical Paper
Study of Parametric Variation on Braking Performance of a Tyre2024-26-037701/16/2024
Braking Performance of a vehicle is one of the most important parameters when it comes to the safety of a vehicle. With rapidly changing tyre & vehicle technology and driving surfaces, its critical to study and quantify the impact of various operational parameters on braking. This study focusses to determine the level of variability in braking performance of a tyre with respect to change in operational and tyre structural parameters. It would hence also assist in defining more accurate test methodology to conduct brake tests. Uncontrolled sources of variability included in study are variation of driver, surface temperature & vehicle, while controlled sources of variability included in study are applied brake force, tyre construction, inflation pressure & test load. The concerned parametric variations have been studied on stand-alone basis as well as combination of more than a single factor. It has been observed that braking in panic condition with higher brake force may not yield the
Tomer, Avinash, Moorthy, Vishnu A, Ghosh, Prasenjit, Mukhopadhyay, Rabindra
Technical Paper
A Study on Effect of Regenerative Braking on Vehicle Range and Axle Life.2024-26-024001/16/2024
During braking condition in EVs, the braking energy is split between the friction braking & regenerative braking. The friction brake fraction will be lost as heat & regenerative brake fraction is converted into electrical energy. In regeneration mode the amount of energy harnessed depends on the regenerative torque available & the rate at which that torque is achieved. If the regenerative torque is higher and if the rate of achieving that torque is higher, energy harnessed will be higher. But higher regenerative torque & higher rate of torque affect the life of the axle components like bevel gear, crown wheel pinion, spider gear & bearing etc & causes gear failure like gear pitting on coast side if proper regeneration torque maps are not defined. This paper gives an outline on effect of different regenerative braking torque values and their rate on the vehicle range and reliability, failure & life of the axle components. Initially an ideal situation with 100% regeneration torque
S, Srivatsa, Pethkar, Shivanand, Ghosh, Sandeep
Technical Paper
Brake Pad Life Monitoring System using Machine learning2024-26-003201/16/2024
In vehicles, Brake Pad is an important part for controlled driving and safety. Brake Pads are made up of friction materials which wear with use. Excessive pad wear may lead to increase the brake response time and NVH issues. Currently it is not feasible for customers to check the amount of brake pad wear without the support from experienced personnel as the unit is not visible from outside. In general no feature is provided by Indian OEMs for brake pad life estimation and indication. This paper proposes a hybrid machine learning approach to predict brake pad remaining useful life. It comprises of 3 modules namely weight, temperature and wear module. Weight module is based on mathematical formulation using longitudinal vehicle dynamics to estimate the weight of the vehicle which is essentially required to calculate kinetic energy dissipated during braking. Temperature and wear module are deep neural network based machine learning modules. The technology is developed in a simplified
Iqbal, Shoaib, BHAMBRI, MIHIR, lahase, Rahul
Technical Paper
Calibration of an Inertial Measurement Unit and its Impact on Antilock Braking System Performance2024-26-001401/16/2024
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
Technical Paper
Anti-Rollback Function for Electric Vehicles without ABS/HSA System.2024-26-009601/16/2024
In high-end commercial vehicles, technologies like Electronic Braking Systems (EBS) help pull away the vehicle from a standstill on steep gradients with no risk of rolling back. Tata Motors has developed an indigenous Anti-Roll Back (ARB) system that effectively minimizes this risk but without the use of EBS/HSA. The ARB delivers identical functionality to the HSA feature in the EBS but autonomously, and by purely electric means. In the proposed system the electric traction motor develops a high positive torque when the vehicle tries to roll back upon minimal accelerator pedal press. The system is autonomous in the sense that the driver does not need to press any HSA switch on the dashboard and the system works on relatively flatter road also which otherwise is not the case with HSA as it negatively affects the operation on flatter road by locking wheels and vehicle launches with a very high torque when brakes are automatically released by EBS upon threshold torque build-up. The launch
Ganguly, Sutanu, Amancharla, Naga Chaithanya, Sharma, Santosh, Shukla, Amisha, Singh, Upendra, Abhirag, Abhirag
Technical Paper
Regulatory trends for enhancement of Road Safety2024-26-016501/16/2024
Various Advanced Driver Assistance systems are being introduced to the Indian Market with the aim of reducing the road fatalities and injuries leading to severe trauma. India being one of the largest markets for the automobile sector always stands committed towards providing safe and sustainable transportation to its citizens. Advanced Driver Systems such as Anti-lock Braking Systems (ABS), Autonomous Emergency Braking systems (AEBS), Lane Departure Warning Systems, Auto Lane Correction Systems, Driver Drowsiness Monitoring Systems, Speed Limiting and Assisting Systems, Automated Crusing Control Systems, Automated Commanded Steering Functions, Traffic Jam assist systems etc., assist the driver during driving. They tend to reduce road accidents and related fatalities by their advanced and artificial intelligent fed programs. This paper will share an insight on the past, recent and the upcoming developments in the regulations with respect to driver assist systems, that are being enforced
Nayak, Pratik, Rawal, Vishal, Patil, Kamalesh, Tandon, Vikram, Badusha, Akbar
Technical Paper
Study on Range Improvement Controls and Method for Electric Vehicles2024-26-013201/16/2024
Electric Vehicles are rapidly growing in the market yet various failure incidents were noted all along the globe. On the other hand, range anxiety has greatly inspired manufacturers to explore new practices to improve. One of the most important components of an EV is the battery, which converts chemical energy to electrical energy thereby liberating heat energy as the loss. This heat loss when high, capability of system to deliver required energy to wheels is reduced significantly. With a higher heat loss in the battery, system is prone to failure or reduced mileage. Therefore, controlling/maintaining system temperature under safe usable zone even during harsh conditions is ideal. Simple reduction in energy consumption of electrical cooling/heating devices used with regenerative energy techniques can greatly help in range improvement. The intention of this paper is to explore easy methods to improve electric vehicle range in different ambient conditions. Few of the key benefactors here
MR, Vikram, Pattalwar, Ashutosh, Verma, Mrinal, Bawa, Vikas
Technical Paper
A novel approach for Combi Braking System design considering tire's nonlinear behavior2024-26-005801/16/2024
The standard usage of Combined Braking System (CBS) in lower cc/power 2-wheeler vehicles serves to reduce stopping distance and improve braking stability. The CBS system achieves this by engaging both the front and rear wheel brakes, taking advantage of the high load transfer characteristic during 2-wheeler braking. However, the current design of the CBS system relies on linear system analysis, based on vehicle geometry, load distribution, and tire-road friction. This approach overlooks the non-linearities inherent in braking dynamics, such as tire behavior and dynamic Center of Gravity (CoG) location. Consequently, the current CBS design methodology exhibits limitations, particularly in extreme scenarios where wheel lock-up may occur, such as on low friction surfaces or during panic braking. This paper proposes the incorporation of tire non-linearities into the design of CBS systems using Pacejka's tire model. Initially, calculations are performed to optimize the braking
Khandekar, Piyush, Badiger, Kartik, Gautam, Ashish, Soni, Lokesh
Technical Paper
Regeneration Calibration for optimum Range and effective brakes performances in eSUV2024-26-011001/16/2024
Regenerative braking is an effective approach for electric vehicles (EVs) to extend their driving range. To enhance the braking performances and regenerative energy, regenerative braking control strategy based on multi objective optimisation is explained in this paper. This technical paper would be focusing on extracting optimum Range with effective brake performances without affecting drivability and performances in different drives modes. An extensive research study on public road driving patterns is done to understand the percentage utilisation of brakes at various (low-mid-high) speeds as per the customer driving behavior. Multi-Objective optimisation function with three vital factors is defined where output generated power, torque smoothness and current smoothness are selected as optimisation objective to improve the driving range, braking comfort, and battery lifetime respectively. Braking regeneration maps are calibrated along with optimised foundation brake hardware’s to get
KUMAR, Prabhakar, K, Rajakumar, Krishnan, Nandhakumar, Suhail, Mohammed thamjeed
Technical Paper
Friction Performance Analysis of Mine Wet Multi-Disc Brake02-17-01-000110/28/2023
Abstract This article takes the wet multi-disc brake used in mining Isuzu 600P as the research object, establishes a simplified three-dimensional model of its key components through SOLIDWORKS and imports it into ANSYS Workbench to establish the flow field and structure field model of the wet brake. Based on the fluid–solid coupling, the finite element simulation of the temperature field and stress field of the friction pair of the wet brake under different braking pressures, braking initial speeds, and fluid viscosities was carried out, and then the position changes of the friction pairs at high temperature hot spots and high stress points were analyzed to determine the stability of its friction performance. Finally, by comparing the temperature change curves of the same point during the braking process under different braking conditions, the validity of the finite element analysis results is verified. The results show that the flow field pressure inside the wet brake is opposite to
Zhang, Chuanwei, Jin, Xiaohe, Zhao, Dawei, Liu, Jinpeng
Journal Article
Recurrent Neural Network Model for On-Board Estimation of the Side-Slip Angle in a Four-Wheel Drive and Steering Vehicle15-17-01-000309/23/2023
Abstract A valuable quantity for analyzing the lateral dynamics of road vehicles is the side-slip angle, that is, the angle between the vehicle’s longitudinal axis and its speed direction. A reliable real-time side-slip angle value enables several features, such as stability controls, identification of understeer and oversteer conditions, estimation of lateral forces during cornering, or tire grip and wear estimation. Since the direct measurement of this variable can only be done with complex and expensive devices, it is worth trying to estimate it through virtual sensors based on mathematical models. This article illustrates a methodology for real-time on-board estimation of the side-slip angle through a machine learning model (SSE—side-slip estimator). It exploits a recurrent neural network trained and tested via on-road experimental data acquisition. In particular, the machine learning model only uses input signals from a standard road car sensor configuration. The model
Giuliacci, Tiziano Alberto, Ballesio, Stefano, Fainello, Marco, Mair, Ulrich, King, Julian
Journal Article
Recurrent Neural Network Model for On-Board Estimation of the Side-Slip Angle in a Four-Wheel Drive and Steering Vehicle15-17-01-0003-TEST-REC09/23/2023
Abstract A valuable quantity for analyzing the lateral dynamics of road vehicles is the side-slip angle, that is, the angle between the vehicle’s longitudinal axis and its speed direction. A reliable real-time side-slip angle value enables several features, such as stability controls, identification of understeer and oversteer conditions, estimation of lateral forces during cornering, or tire grip and wear estimation. Since the direct measurement of this variable can only be done with complex and expensive devices, it is worth trying to estimate it through virtual sensors based on mathematical models. This article illustrates a methodology for real-time on-board estimation of the side-slip angle through a machine learning model (SSE—side-slip estimator). It exploits a recurrent neural network trained and tested via on-road experimental data acquisition. In particular, the machine learning model only uses input signals from a standard road car sensor configuration. The model
Giuliacci, Tiziano Alberto, Ballesio, Stefano, Fainello, Marco, Mair, Ulrich, King, Julian
Journal Article
Model Based NVH Simulator for Virtual Development2025-01-005905/05/2023
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
Technical Paper
Electric Bus NVH Challenges and Refinement Using Innovative Approach2025-01-008005/05/2023
The trend towards electrification propulsion in the automotive industry is highly in demand due to zero-emission and becoming more significant across the world. Battery electric vehicles have lower overall noise as compared to conventional I.C Engine counterparts due to the absence of combustion engine noise. However, other narrowband and tonal noises are becoming dominant and are strongly perceived inside the cabin. With the ongoing push towards electrification, there is likely to be increased focus on the noise impact of gearing required for the transmission of power from the electric motor to the road. Direct coupling of E-motors with Axle has resulted in severe tonal noises from the driveline due to instant e-motor torque ramp up from 0 rpm and reverse torque on driving axle during regenerative braking. The tonal noises from the rear axle during vehicle running become very critical for customer perception. For automotive NVH engineers, it has become a challenge to balance expected
Doshi, Sohin, Kalsule, Dhanaji, Sawangikar, Pradeep, Suresh, Vineeth, Sharma, Manish
Technical Paper
Brake Noise CAE Enhancement with the Synergy between Design of Experiments and Machine Learning2025-01-012405/05/2023
The digitalization of industrial systems has led to increased data availability. Machine learning (ML) methodologies are now commonly used for data analysis in industrial contexts. Not all contexts have abundant data; sometimes data collection can be scarce or expensive. DOE is a technique that provides an informative dataset for ML analysis when data are limited. It involves systematically designing experiments to collect relevant data points with regression models. Disc brake noise is a challenging problem in vehicle noise, vibration, and harshness (NVH). Different noise events occur under various operating conditions and across frequencies (1-16 kHz). To enhance computer-aided engineering (CAE) techniques for brake noise, ML is used to generate additional data. Sequential experimentation in DOE aligns well with ML’s ability to continuously learn and improve as more data become available. DOE is applied in CAE to collect data for training ML models. ML helps find patterns in high
Song, Gavin, Venugopal, Narayana, Vlademar, Michael
Technical Paper
Comparison of On-Road Highway Fuel Economy and All-Electric Range to Label Values: Are the Current Label Procedures Appropriate for Battery Electric Vehicles?2023-01-034904/11/2023
As consumers transition from internal combustion engine (ICE)-powered vehicles to battery electric vehicles (BEV), they will expect the same fuel economy label-to-on-road correlation. Current labeling procedures for BEVs allow a 0.7 or higher multiplier to be applied to the unadjusted fuel economy and range values. For ICE-powered vehicles, the adjustment factor decreases with increasing unadjusted fuel economy and can be lower than 0.7. To better inform consumers, starting in 2016, Car and Driver added an on-road highway fuel-economy test, conducted at 120 kph (75 mph), that augments the performance metrics that it's been measuring since the 1950s. For electric vehicles, testing includes an evaluation of the all-electric range.The on-road test results were aligned with the certification information for each vehicle model including unadjusted and label fuel economy and range, road load force coefficients, and labeling options. Tractive energy and kinetic energy available for
Pannone, Gregory, VanderWerp, Dave
Technical Paper
Comparative Numerical Study on Heat Dissipation Behaviour of Conventional Disk Brake Designs for High-Performance Requirements.2022-28-042211/09/2022
The braking system of a vehicle is one of the most crucial parts for proper and safe operation. It is required to slow down and/or stop the vehicle and work by converting the kinetic energy of the wheel to heat. It is essential to dissipate the generated heat for optimal working and the long life of the disc brakes. Most of the complications and failures with a brake disc are due to problems with heat distribution and heat level absorbed by the disc. The heat is generated due to friction between the brake pad and disc. Due to overheating of brakes due to prolonged braking and heavy braking, brake fade occurs which leads to boiling of the brake fluid, gassing, and glazing of brake pads and hence reducing braking performance. Therefore, in this project, our aim is to determine the best design that allows for the most heat dissipation by analyzing four different disc brakes using computer simulations i.e CFD to study the effect on airflow and convection and FEA for thermal analysis. This
Arora, Rishabh, Rao, Vikram, Sharma, Rishab, Chahal, Rujul, Singh, Manvesh
Technical Paper
Tutorial: Corrosion Phenomena in Brake Systems: From Basics to Future Challenges1334510/11/2022
Corrosion on braking systems is an important issue in the automotive sector. In particular, short term corrosion of the grey cast iron discs can lead to undesired corrosion attack at dealers, while long term corrosion might impair comfort and durability of the braking system. Moreover, corrosion attack of the grey cast iron might cause stiction phenomena between the breaking pad and disc leading to possible damage of the pad. Corrosion phenomena became more important for electrified power train vehicles. In this tutorial, will try to explain the basis of the electrochemical mechanism, some characterization techniques and the interaction on the stiction phenomena between the brake pad sample and the rotor (gray cast iron). Also, another aspect that will be considered is the rust removal conditions and simulations when we are considering Electric Vehicles. The goal is to give to the audience an overview from the basics of the electrochemistry to the experimental conditions test that will
Sin, Agusti
Video
The Validation of an Empirical Disc Brake Model with Full-Vehicle Brake Tests2022-01-508210/06/2022
The brake of a vehicle is of particular importance for vehicle safety. Brake inspection is an essential part of the periodic technical inspection and contributes to road safety. The current vehicle brake inspection methods are mostly tied to brake tester and check the vehicle brake in a workspace that does not have much practical relevance. Therefore, an attempt is made to develop dynamic inspection methods for automotive brakes, which are based on driving tests. To develop these dynamic inspection methods, a vehicle model is used, which includes an empirical brake model that takes into account the various dependencies of the coefficient of friction of the friction pairing of automotive disc brakes. The model is later validated with full-vehicle brake maneuvers from different velocities and under different conditions and shows good results.
Schramm, Tobias, König, Pascal, Kubenz, Jan, Prokop, Günther
Technical Paper
A Novel Approach for the Frequency Shift of a Single Component Eigenmode through Mass Addition in the Context of Brake Squeal Reduction15-16-01-000409/23/2022
Abstract Brake squeal reduces comfort for the vehicle occupants, damages the reputation of the respective manufacturer, and can lead to financial losses due to cost-intensive repair measures. Mode coupling is mainly held responsible for brake squeal today. Two adjacent eigenfrequencies converge and coalesce due to a changing bifurcation parameter. Several approaches have been developed to suppress brake squeal through structural changes. The main objective is to increase the distance of coupling eigenfrequencies. This work proposes a novel approach to structural modifications and sizing optimization aiming for a start at shifting a single component eigenfrequency. Locations suitable for structural changes are derived such that surrounding modes do not significantly change under the modifications. The positions of modifications are determined through a novel sensitivity calculation of the eigenmode to be shifted in frequency. In the present work, the structural changes are carried out
Deutzer, Marcel, Stender, Merten, Tüpker, Nicolas, Hoffmann, Norbert
Journal Article
Design of a Laboratory Sampling System for Brake Wear Particle Measurements2022-01-117909/19/2022
Brake wear is one of the dominant sources of traffic-related particulate matter emissions and is associated with various adverse environmental and health hazards. To address this issue, the UNECE mandated the Particle Measurement Program to develop a harmonized methodology for sampling and measuring brake wear particles with a full-flow dilution tunnel on a brake dynamometer. Here we present the design of a novel, fully PMP compliant sampling tunnel. The dimensions and general layout of the tunnel are based on minimization of super-micron particle losses and consideration of space limitations in brake-dynamometer setups as well as the need for efficient utilization of the test facilities (reduced testing times). Numerical calculations suggested that the critical section of the system is the sampling train from the sample probes to the instrumentation inlet/filter holder. An optimal sampling train flow of ~10 l/min was identified and formed the basis for the design of a dedicated PM
Mamakos, Athanasios, Huber, Michael Peter, Arndt, Michael, Reingruber, Herbert, Steiner, Gerald, Weidinger, Christoph
Technical Paper
Kinetics of Moisture Adsorption and Its Impact on Brake Pad Compression Modulus and Compressibility: Compression Modulus vs. Dynamic Modulus and Friction Variation2022-01-116509/19/2022
The kinetics of moisture adsorption is studied for copper-free brake pads. The pad weight gain is found to increase linearly with the square root of exposure time to humidity at a given temperature – the higher the humidity, the higher the weight gain. As the moisture content in the pad increases, the tangent modulus increases while the secant modulus decreases, resulting in decreasing compressibility associated with the tangent modulus of compression and increasing compressibility associated with the secant modulus of compression – compressibility defined as a reciprocal of compression modulus. Compression modulus and dynamic modulus are compared, and implications for friction coefficient variation are discussed. A rate constant of adsorption is proposed to define and compare moisture sensitivity of friction materials.
Rhee, Seong Kwan, Rathee, Aman, Singh, Shiv Raj, Sharma, Devendra
Technical Paper
The Effects Of Corrosion On Particle Emissions From A Grey Cast-Iron Brake Disc2022-01-117809/19/2022
Reducing exhaust emissions has been a major focus of research for a number of years since internal combustion engines (ICE) contribute to a large number of harmful particles into the environment. As a way of reducing emissions and helping to tackle climate change, many countries are announcing that they will ban the sale of new ICE vehicles soon. Electrical vehicles (EVs) represent a popular alternative vehicle propulsion system. However, although they produce zero exhausted emissions, there is still a concern of the non-exhausted emission, such as brake dust, which can still cause harm to human health and the environment. Despite EVs primarily using regenerative braking, they still require friction brakes to supplement as and when required. Moreover, EV’s will likely continue to use the traditional grey cast iron brake rotor, which is heavy and prone to corrosion which may exacerbate the brake wear emissions. This study concentrates on emissions from a conventional grey cast iron
Ghouri, Ishmaeel, Barker, Richard, Kosarieh, Shahriar, Brooks, Peter, Barton, David
Technical Paper
Brake Pad Wear Monitor using MOC(Motor On Caliper) EPB ECU2022-01-116709/19/2022
With the spread of new trends such as autonomous driving and vehicle subscription service, drivers may pay less attention to the maintenance of the vehicle. Brake pads being safety critical components, a wear indicator is required by the regulation. Current application of the wear indicator in the market uses whether sound generating metal strip or wire harness based pad wear sensor. The former is not effective in generating clear alarm to the driver, and the latter is now cost effective, and there is a need for more effective and low cost solution. In this paper, a pad wear monitoring system using MOC(Motor On Caliper) EPB(Electric Parking Brake) ECU is proposed. An MOC EPB is equipped with a motor, geartrain and an ECU. The motor current when applying the parking brake is influenced by the mechanical load at the brake pad side of the system. So, by analyzing the time history of the current it is possible to measure the clearance between brake pad and disc induced by the pad wear
Lee, Soohyuk
Technical Paper
Effect of Humidity Levels on the Compressibility of Automotive Brake Friction Materials2022-01-116409/19/2022
The load-deflection relationship of automotive brake friction materials (also known as “compressibility”) is a characteristic which may both influence and advise as to brake performance, including driver experience, noise and vibration behavior, and manufacturer quality control. It has been reported that changes in environmental humidity may significantly alter friction material compressibility in a formulation-dependent fashion – effects which are important considerations for testing protocols and real-world applicability. Greening’s presentation includes a rigorous investigation of humidity-dependent properties across differing friction materials and manufacturers, taking advantage of the high resolution and excellent repeatability of the Greening Model 1140 Compressibility Test Machine. Sets of brake pads from (at least) two different manufacturers and of varied material type (non-asbestos organic, semi-metallic, low-metallic, etc.) will be weighed to assess changes to moisture
Sendler, Edward, Greening, Brent, Greening, Chuck
Technical Paper
Enhancing Meta Model of the Brake Pad Friction Coefficient using the Explainable Machine Learning2022-01-117509/19/2022
As 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 rotational speed of the brake disc, the disc temperature, and the hydraulic pressure. Furthermore, it varies depending on the driving scenario even the same condition. Therefore, there was a need for a new method : machine learning to solve this problem. A Mixed Effect
Cho, Sunghyun, Bang, Sunghoon, Jang, Jiwoo, Kim, Youngjae
Technical Paper
Improving Functionalities of Existing Electronic Stability Controller by adding Sensor Detection Based Algorithm for Collision Avoidance using CarSim.2022-01-116809/19/2022
With the advent of autonomous driving into mobility industry, passenger safety is of paramount importance. Electronic Stability Control (ESC) has been widely employed as an active safety feature in most of the modern cars, ESC is majorly based on differential braking, steer by wire or active torque distribution to prevent the vehicle from going off-course. However, ESC is limited to the discretion of the driver. Thus, the objective of this paper is to improve functionalities of existing electronic stability control by adding sensor detection-based algorithm for collision avoidance. The subject vehicle is installed with an existing default ESC & ABS system along with two range tracking sensors at front and rear and two blind spot detection sensors. The algorithm for collision avoidance has been tested in CarSim 2021.1. The procedure is tuned on different complex highway driving scenarios where a crate falls off from a traffic vehicle moving ahead of the subject vehicle along with
Shaikh, Parvez, Debnath, Sarnab, Kamble, Vijay, Mallikarjunaiah, Umesh
Technical Paper
Investigation and Analysis of Brake Factor variation and its relation with Brake Pulling.2022-01-117109/19/2022
Vehicles pull during braking can be defined as the deviation of vehicle travel from intended path of the vehicle by a margin of half a wheel track or more. It is a dynamic phenomenon with very complex inter-dependencies among the combined functioning of various aggregates such as steering system, suspension system, axles, brakes. The problem is aggravated with shorter wheelbase & higher CG (Centre of Gravity) height, where the instantaneous load transfers are sudden and of relatively high magnitude which can lead to a combination of forces that are responsible for vehicle drifting or pulling to anyone side of center-line travel. Vehicle with shorter wheelbases, high GVW and high CG heights are more prone to this unstable behavior due to sudden change in dynamic forces acting on the tires while turning and braking. Although these vehicles have some disadvantages, they are required for important applications such as stage and intercity operations and hence cannot be stopped producing due
Pandey, Prashant, Pujari, Sachin, Nagrikar, Ravi
Technical Paper
Re-imagining Brake Rotor Thermal Fatigue Testing to Relate to Field Use2022-01-116309/19/2022
The validation of brake rotors has remained, to this day, heavily reliant on “Thermal Abuse” or “Thermal Cracking” type testing, with many procedures so dated that most engineers active in the industry today cannot even recall the origin of the test. These procedures - of which there are many variants - all share the trait of greatly accelerating durability testing by performing repeated high power (high speed and high deceleration) brake applies to drive huge temperature gradients and internal stress, and often allowing the rotor to get very hot, to where the strength of the material from which the rotor is constructed is significantly degraded. There is little debate about whether these procedures work; by and large rotor durability issues in the field are extremely rare. However, without the connection to the duty cycle in the field, it is extremely difficult to interpret results (especially since many standards allow significant cracking before a failure is declared), and this can
Antanaitis, David, Langhardt, Jerry
Journal Article
Estimating Brake Pad Life in Regenerative Braking Intensive Vehicle Applications2022-01-116109/19/2022
Regenerative braking without question greatly impacts brake pad service life in the field, in most cases extending it significantly. Estimating its impact precisely has not been an overriding concern - yet – due in part to the extensive sharing of brake components between regen-intensive battery-electric and hybrid vehicles, and their more friction-brake intensive internal combustion engine powered sibling. However, a multitude of factors are elevating the need for a more accurate estimation, including the emerging of dedicated electric vehicle architectures with opportunities for optimizing the friction brake design, a sharp focus on brake particulate emissions and the role of regenerative braking, a need to make design decisions for features such as corrosion protection for brake pad and pad slide components, and the emergence of driver-facing features such as Brake Pad Life Monitoring. Tackling this question raises questions such as “is the proven braking energy and temperature
Antanaitis, David, Robere, Matthew
Journal Article
Onboard Sensor and Actuator Calibration of a Tripod Electric Vehicle Using Circular, Linear, and Cornering Motion Tests02-16-01-000608/09/2022
This article aims at the calibration of an onboard sensor and actuator parameters as well as the identification of the open-loop transfer function of the steering and traction control systems of tripod electric vehicles (EVs). Tripod EVs are commonly used as forklifts and automatic guided vehicles in a factory or wheelchairs in a hospital. A test procedure called the circular, linear, and cornering motions (CLCM) test is introduced in this article for making the corrections which are caused by many factors including the potentiometer of the steering angle error, hall sensor error of the traction speed, the backlash of the steering system, and the tire slip angle that can lead the tripod EV to deviate from the path. The CLCM test is subdivided into circular, linear, and cornering motion subtasks for each individual identification and calibration purposes. The effect of the CLCM test has been verified by both simulation and experiment via an 8-shape navigation path consisting of all
Ismail, Hasan, Chiang, Chien-Hsun, Chieng, Wei-Hua
Journal Article
Design, Simulation and Topology Optimization of Rotor Disc2022-26-118805/26/2022
Brake systems are one of the most critical components of any mobile vehicle. They play a vital role in providing safety to the passengers, vehicle and surroundings. It works on basic principle of Pascals Law by applying forced frictional resistance to the rotating members of the vehicle to slow down the speed. Generally, cast iron is used as a primary material for the rotor in different applications. The current study involves the modelling of the Brake disc according to general specifications of All Terrain Vehicle and performing FEA Analysis on brake disc to study different results. The FEA analysis include the static structural to test the rigidity and ruggedness of disc, Steady and Transient Thermal Analysis to study the behavior of disc under varying thermal loads. It includes study of various parameters such as Von Mises Stress, Total Deformation, Thermal Gradient and Total Heat flux across the brake disc to evaluate the performance under extreme conditions. Different types of
Ruparelia, Rudra, Patel, Aarya, Baxi, Neel
Technical Paper
V4-002 FK testSAE-PP-0095504/26/2022
Heavy vehicles are essential for the modern economy, delivering critical food, supplies, and freight throughout the world. Connected heavy vehicles are also driven by embedded computers that utilize internal communication using common standards. However, some implementations of the standards leave an opening for a malicious actor to abuse the system. One such abuse case is a cyber-attack known as the “Address Claim Attack.” Proposed in 2018, this attack uses a single network message to disable all communication to and from a target electronic control unit, which may have a detrimental effect on operating the vehicle. This article demonstrates the viability of the attack and then describes the implementation of a solution to prevent this attack in real time without requiring any intervention from the manufacturer of the target devices. The defense technique uses a bit-banged Controller Area Network (CAN) filter to detect the attack. Once an attack is discovered, the defender induces a
Mutagaana, Festo
Pre-Print Article
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
Technical Paper
Methodology and application on load monitoring using strain-gauged bolts in brake calipers2022-01-112103/29/2022
As technology evolves, the number of sensors and available data on vehicles grow exponentially. In this context, it is essential to use sensors for monitoring key components, increasing safety and reliability, and gathering data useful for mechanical dimensioning and control systems. This paper presents an application of strain-gauged bolts brake calipers fixation of two electric vehicles. With this approach it was possible to obtain the loads applied to the brake pads and correlate them with braking behavior, therefore gaining insights on braking conditions and system state. The goal of the study is analyzing the strengths and limitations of the method and proposing developments to deploy it in real applications. This topic is particularly important and novel for electric vehicles, where powertrains can create positive and negative torques and generate complex interactions with braking system. Strain-gauges are a long-known technology applied in many fields, and its usage in bolts and
de Carvalho Pinheiro, Henrique, Sisca, Lorenzo, Carello, Massimiliana, Ferraris, Alessandro, Airale, Andrea Giancarlo, Falossi, Marco, Carlevaris, Alberto
Technical Paper
Hardware-in-the-loop testing of a hybrid Brake-by-wire system for electric vehicle2022-01-111603/29/2022
Recent trends in automotive engineering, such as electrification and automation, are opening chances as well as challenges due to the need of new chassis components (e.g., drivetrain, brakes, steering, suspension etc.) and control methods. Mechatronic components, so called X-by-wire systems, seem to become game-changers since they allow more efficient vehicle control with a higher operational speed for improving active safety, efficiency and driving comfort. Especially brake-by-wire (BBW) applications step into foreground, since they affect the bespoken aspects but have a limited use on serial vehicles yet due to the current maturity and the high impact of the systems on vehicle architecture. On the other hand, those systems have many advantages e.g., adjustable pedal feel, continuous wheel slip control and more effective recuperation of brake energy. Electromechanical brakes (EMBs) do not need brake fluid which make them easier to integrate (no pipes, no bleeding) and increase
Heydrich, Marius, Ivanov, Valentin, Büchner, Florian, Bertagna, Alessandro, Rossi, Alessandro, Mazzoni, Matteo
Technical Paper
Novel Nanocrystalline Silver Alloy Coatings to Boost Performance of EV High Voltage Interconnects and Charging Interfaces2022-01-087403/29/2022
Electric vehicle performance needs challenge connector designers and powertrain engineers with new paradigms for performance under more rigorous operational conditions. Traditional connector design protocols direct the engineer to silver plating for the contact interface, but these coatings have a maximum interface temperature of 170 C (ambient temperature plus T-rise). To avoid thermal runaway, engineers have to derate the ampacity of powertrain connections, which reduces available energy delivery as the temperature increases. This is especially true during transient power events like regenerative braking and acceleration. The soft nature of silver coatings make them well suited for power delivery and low contact resistance, but requires an engineering trade-off for wear durability. This is especially problematic for charging connectors which require tens of thousands of mating cycles before failure. In this work, we demonstrate the performance enhancements that can be achieved using
Griffiths, Peteris, HILTY, Robert, Chan, Lisa, Cahalen, John
Technical Paper
Off-Road Rover Mobility Simulation Using a Continuum Representation of Deformable Terrains 2022-01-041803/29/2022
We seek to develop control policies for optimized rover mobility on deformable granular material terrains using a co-simulation framework implemented in an open-source simulation platform. An elasto-plastic continuum model is employed for the purpose of increasing the simulation speed in capturing the dynamics of the deformable granular material terrain. The solution of the continuum problem is obtained using the smoothed particle hydrodynamics (SPH) method; the rover is handled as a multibody system with constraints. Both the rover body and wheels are defined via geometries specified through triangular meshes. The two-way coupling between each wheel and the deformable terrain is implemented using so-called boundary conditions enforcing (BCE) particles attached to the rover wheel. A traction control algorithm is proposed to reduce wheel slip and hence power/energy usage in a hill-climbing scenario. The study is carried out in an in-house developed open source code called Chrono. The
Hu, Wei, Zhou, Zhenhao, Serban, Radu, Negrut, Dan
Technical Paper
Hybrid Drivetrain Design Using a Power Curve Heuristic Method2022-01-079403/29/2022
Emerging electrified powertrains benefit from efficient conversion and regenerative braking by storing energy in batteries rather than liquid or gaseous fuels. The downside of batteries, however, is that they're heavy and expensive compared to Diesel or Hydrogen fuel. A hybrid drivetrain, compared to a purely electric vehicle, can provide many of the same benefits with a much smaller battery. A heuristic is proposed to design hybrid vehicle architectures which achieve high energy efficiency while minimizing the mass and cost of onboard components. The heuristic uses vehicle power-energy curves to size motor, battery, engine, fuel cell, and hydrogen storage components to meet the required peak power and total energy storage requirements for various commercial vehicles configured as parallel, series, or powersplit hybrids. Commercial vehicles have distinct duty cycles to which a hybrid system must be closely tailored. The heuristic design method is verified using a vehicle drivetrain
Miller, Eric
Technical Paper
Research on Brake Pads Particle Emissions and Temperature Reduction of a Brake Disc in Air Controlling System.2022-01-039003/29/2022
This paper addresses the brake pad particles emitted during the braking process of a vehicle in motion. The frictional-constant contact between the disc brake and brake pads generates thermal energy as a result of increased temperature within the brake disc causing wear of the brake pads. Emission of brake pad particles into the atmosphere leads to an increase in air pollution in the environment and hence becomes hazardous to the human body. In this paper, the wheel brake disc is installed in a ventilated system where the specific airflow encompassing the disc brake accounts for thermal performance and pad particle emission from the brake pads. The mathematical model of the fundamental parameters of the brake disc and ventilation is established and the behavior of heat transfer coefficient, heat generation, heat flux, temperature rise, airflow rates, brake disc cooling time, inlet and outlet speed on the ventilation system with the brake disc are carried using computational fluid
sarvar, Yovkachov, Fayzullayevich, Jamshid Valiev
Technical Paper
Hierarchical Vehicle Stability Control Strategy Based on Unscented Kalman Filter Estimation2022-01-034303/29/2022
High-speed vehicle is prone to instability under bad road conditions, causing many safety accidents such as tail-flicking and overturning. Stability control could assist vehicle to drive safely and stably by adjusting the additional yaw moment. However, most of the existing stability control strategies directly invoke the information of the sideslip angle of the centroid that is difficult to obtain on the vehicle, and carry out complex controller design, which deviates from the actual application. In order to achieve a complete set of stability control architecture oriented to practical applications, this paper designs a hierarchical vehicle stability control strategy based on differential braking and state estimation technology. Firstly, a model oriented to state estimation and controller design is built according to the vehicle's motion state; Secondly, the sideslip angle of the centroid is accurately estimated through the unscented Kalman filter algorithm; Subsequently, the sliding
Zhang, Jian, Jiang, Hongwei, Li, Linrun, Liu, Qiuzheng, Wang, Yu, Liu, Jinbo, Gao, Yuan, Chen, Zhicheng
Technical Paper
Active brake wheel cylinder pressure control based on integrated electro-hydraulic brake system2022-01-034203/29/2022
With the development of automobile industry, the requirements of quick response, high performance are put forward for the braking system. Since the traditional braking system cannot achieve these, the international brake parts manufacturers put forward an integrated electronic braking system -the 1-Box. It can realize active braking through the servo motor. In addition, by controlling the pressure of servo cylinder and working with solenoid valves, the wheel cylinder pressure can be controlled. However, it has some problems, such as hydraulic hysteresis disturbance and complex friction obstruction, which cause obstacles to the accurate control of wheel cylinder pressure. In this paper, the active brake pressure control strategy of wheel cylinders is designed based on 1-Box. First, introduce the configuration and the working principle of wheel cylinder pressure control; Next, design the servo cylinder active brake pressure control strategy composed of servo ring and pressure ring. Servo
Zhang, Jian, Li, Linrun, Jiang, Hongwei, Liu, Qiuzheng, Wang, Yu, Yuan, Wenjian, Wu, Jian, Zhang, Xuhan
Technical Paper
Visual System Analysis of High Speed on-off Valve Based on Multi-physics Simulation 2022-01-046503/29/2022
High speed on-off valves(HSV) are widely used in advanced hydraulic braking actuators, including the regenerative braking system and the active safety system, which take crucial part in improving the energy efficiency and safety performance of vehicles. As a component involving multiple physical fields, the HSV is affected by interaction of fluid, electromagnetic, mechanical, and even the temperature. Since the opening of the HSV is small and the flow speed is high, cavitation and vortex are inevitably brought out so that increase the valve’s noise and instability. However, it is costly and complex to observe the flow status by visual fluid experiments. Hence a visual multi-physics system simulation model of HSVs is explored in this paper, in which the flow field model of the HSV built by the computational fluid dynamic (CFD) is co-simulated with the model of hydraulic control actuator established by AMESim. Accordingly, the pressure and the opening of the HSV are variable with actual
Meng, Aihong
Technical Paper
Measurement and evaluation of the conversion of thermal energy generated on the contact surface of the brake disc into electrical energy using a thermoelectric generator2022-01-021303/29/2022
The heat generated by the friction between the brake discs and the brake pad, causes the disc’s temperature to rise which affects braking performance. This generated heat flux from the contact surface of the vehicle’s brake disc does not only affect braking performance but also tend be wasted and pollute the environment. However, an accurate system is needed to make efficient use of this generated heat flux, that is usually wasted. Thermoelectric generators (TEGs) are solid-state gadgets utilized in the conversion of heat to electricity. Hence, the aim of this study is to convert the heat flux generated at the disc contact surface into electrical energy by employing a thermoelectric generator. Additionally, to store the harvested energy to power the battery which in turn charges the temperature monitoring systems. Thermoelectric generators were positioned at different geometrical points of the brake discs to achieve optimal efficiency and energy storage possibilities. A static model is
Fayzullayevich, Jamshid Valiev, Agyeman, Philip, Frimpong, Justice
Technical Paper
Design and Hardware in the Loop testing of AEB controllers2022-01-010603/29/2022
Current ADAS systems can improve vehicle safety directly influencing its dynamics, reducing the impact of human error while driving. These functionalities have a high impact on the complexity of each unit installed on the car, potentially increasing the development time. In this work, a Hardware in the Loop testing methodology for Autonomous Emergency Braking system is presented, aiming to enable a faster system development process. A commercial production brake by wire unit has been installed on a real-time driving simulator. The AEB functionality of the unit is activable in real-time during the simulation, by the means of a customizable control strategy. Three different AEB controllers have been implemented: the first one reproduces the unit stock functionality, while the two remaining compute the requested deceleration using a PID and a Fuzzy control strategy. The three controllers have been tested in standardized EuroNCAP Car-to-Car Rear (CCR) collision scenarios, implemented on
Alfatti, Federico, Garinei, Michele, Annicchiarico, Claudio, Capitani, Renzo
Technical Paper
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