Browse Topic: Anti-lock braking (ABS)

Items (347)

NASA’s Inspection Technology for Spacecraft Tests Quality of Seacraft Hulls

TBMG-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.

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

2024-26-001401/16/2024

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

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

Regulatory trends for enhancement of Road Safety

2024-26-016501/16/2024

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

SAE-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

Methodology and application on load monitoring using strain-gauged bolts in brake calipers

2022-01-112103/29/2022

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

Hardware-in-the-loop testing of a hybrid Brake-by-wire system for electric vehicle

2022-01-111603/29/2022

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

Modeling Rack Force for Steering Maneuvers in a Stationary Vehicle

2021-01-128710/11/2021

A steering system converts circular motion of the steering wheel into yaw motion of the road-wheels. In absence of a steering assist mechanism, the driver torque overcomes the tire-road friction forces, which is transmitted to the steering rack through tie rods attached to the road-wheels. The net force acting on the rack is then transmitted to the steering wheel through mechanical linkages which results in a natural haptic feedback, commonly referred to as the steering feel. In an electric/hydraulic power steering, an electro-mechanical actuator applies assist force, which reduces the torque required by the driver. In order to maintain stability of the power steering system while generating a desired steering feel, it is therefore crucial to accurately model steering rack force. We present a model for the rack force, which is generated while performing steering maneuvers in a stationary vehicle. In contrast to the well-known LuGre tire friction model, our rack force model is simpler

Kant, Nilay, Chitkara, Raunav, Pramod, Prerit

SAE J1698-1A Pedestrian Protection EDR Output Data Definition, Appendix to SAE J1698-1 Event Data Recorder - Output Data Definition

J1698/1A_202104 (Current)04/30/2021

SAE J1698-1A creates an appendix to SAE J1698-1. The appendix contains EDR Record parameters and definitions related to light duty passenger vehicle pedestrian protection systems.

Event Data Recorder Committee

Integrated Regenerative Braking System and Anti-Lock Braking System for Hybrid Electric Vehicles & Battery Electric Vehicles

2020-01-084604/14/2020

This paper describes development of an integrated regenerative braking system and anti-lock brake system (ABS) control during an ABS event for hybrid and electric vehicles with drivelines containing a single electric motor connected to the axle shaft through an open differential. The control objectives are to recuperate the maximum amount of kinetic energy during an ABS event, and to provide no degraded anti-lock control behavior as seen in vehicles with regenerative braking disabled. The paper first presents a detailed control system analysis to reveal the inherent property of non-zero regenerative braking torque control during ABS event and explain the reason why regenerative braking torque can increase the wheel slip during ABS event with existing regenerative braking control strategies. Then, the regenerative brake control problem during ABS events is formulated with a unified control system architecture where the regenerative braking torque is coordinated with the friction braking

Yao, Yixin, Zhao, Yanan, Yamazaki, Mark

A Novel Kalman Filter Based Road Grade Estimation Method

2020-01-056304/14/2020

Accurate, robust and real-time estimation of road grade is extremely important in vehicle control (battery management, transmission shift scheduling, distance-to-empty prediction, anti-lock braking system, collision avoidance, stability control, etc.) to improve safety, stability, efficiency and performance. This paper presents a novel Kalman filter based road grade estimation method using measurements from an accelerometer, gyroscope and tachometer. The accelerometer measures the components of the vehicle acceleration (including the components of the acceleration due to gravity), and the measurements provided by the accelerometer are almost drift free but heavily corrupted by measurement noises. The gyroscope measures the components of the angular velocity of the vehicle, and the measurements provided by the gyroscope are quite clean but disturbed by gyroscope biases. The tachometer measures the longitudinal vehicle velocity, and the measurement provided by the tachometer is also

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

2020-01-021604/14/2020

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

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

New Integrated Vehicle Dynamics Control System Based on the Coordination of AFS, DYC, and ED for Improvements in Vehicle Handling and Stability

10-04-02-000901/27/2020

An integrated vehicle dynamics control system aiming to improve vehicle handling and stability by coordinating active front steering (AFS), direct yaw control (DYC), and electric differential system is developed in this article. First, an electric differential system for electric vehicle, composed of two sets of bi-PMS, in-wheel motors connected in parallel and supplied by a single five-leg inverter, one on the front axle and one on the rear axle, is designed. However, each set is controlled by a proposed sliding mode backstepping control, which has replaced the hysteresis controllers in the conventional direct torque control (DTC), can obviously reduce the torque ripple, and provide better speed tracking performance using sliding mode speed controllers. Second, an integrated control system which coordinates AFS and DYC braking system is designed by using a stability index, based on stability domain in the phase plane portrait, and a gain scheduling parameter to improve vehicle

Aouadj, Norediene, Hartani, Kada, Fatiha, Mekri

More than a brake

2019-36-002001/13/2020

The automotive world is battling every day to provide innovation and product development without compromising the environment. The electrification of the engines can be a factor that divides eras into the market. The conventional brake system links the act of apply the brake pedal with the stop or deceleration of the vehicle. This is now possible thanks to the long-term use of the vacuum generated by the combustion engine or by auxiliary equipment (vacuum pump). New brake system technologies provides, without a vacuum source, more efficient and safer braking than the current power brake system. Embedded in technological developments, these systems interacts with other vehicle components (cameras, radars, ABS, ESC) bringing the driver advanced safety conditions.

Batagini, Emerson

Brake System Thermal Performance for Brazil Market Battery Electric Vehicles

2019-36-001901/13/2020

The discussion in the braking industry that has been ongoing for over a decade now on how to specify brake systems for regenerative-brake intensive vehicle applications has intensified considerably in the past few years as the automotive industry ponders a future where electric vehicles become predominant. Major automotive manufactures have announced plans to create dedicated electric-only vehicle architectures, from which to offer a full range of electric vehicle configurations. The time to really figure out the translation of Voice of the Electric Vehicle Customer to technical requirements and brake system content is approaching very rapidly. One of the major design decisions in the brake system is the sizing of foundation brake components for thermal performance. There is no question that regenerative brakes can significantly reduce the demand on the friction brakes in normal usage, sometimes by a full order of magnitude or more. Brakes no longer need to be sized for everyday use

Antanaitis, David

Regenerative Braking Cooperative Control of Hybrid Electric Vehicle Based on System Efficiency Optimization

2019-01-508911/19/2019

In order to improve the performance of electro-hydraulic composite braking system of hybrid electric vehicle (HEV), a new type of plug-in HEV with dual motor was taken as the research object. The model of motor loss was built to achieve maximum motor efficiency, and the hydraulic braking system model, which can dynamically control pressure, was built. Based on the optimization of a motor’s continuously variable transmission (CVT) joint efficiency, the real-time optimal allocation strategy based on threshold method and cooperative control strategy of the electro-hydraulic composite braking system were brought out to recover most of the regenerative energy under the premise of ensuring safety. The model was built to verify the performance by AMESim-Simulink. The results show that the control strategy can take the advantages of dual-motor braking recovery system, increase braking energy recovery rate, effectively improve the braking safety and ride comfort of the vehicle, and reduce

Yang, Yang, Chen, Jing, Luo, Chang, Tang, Qingsong

Braking Control Strategy Based on Electronically Controlled Braking System and Intelligent Network Technology

2019-01-503811/04/2019

In order to solve the coupling problems between braking safety, economical efficiency of braking and the comfort of drivers, a braking control strategy based on Electronically Controlled Braking System (EBS) and intelligent network technology under non-emergency braking conditions is proposed. The controller utilizes the intelligent network technology’s characteristics of the workshop communication to obtain the driving environment information of the current vehicle firstly, and then calculate the optimal braking deceleration of the vehicle based on optimal control method. The strategy will distribute the braking force according to the ideal braking force distribution condition based on the EBS according to the braking deceleration; the braking force will be converted to braking pressure according to brake characteristics. Computer co-simulations of the proposed strategy are performed, the strategy is verified under different initial speeds. The results show that the strategy enables

Zheng, Hongyu, Li, Rui

Information on Brake-By-Wire (BBW) Brake Control Systems

AIR5372A (Current)10/25/2019

This SAE Aerospace Information Report (AIR) describes the design approaches used for current applications of aircraft Brake-by-Wire (BBW) control systems. The document also discusses the experience gained during service, and covers system, ergonomic, hardware, and development aspects. The document includes the lessons that have been learned during application of the technology. Although there are a variety of approaches that have been used in the design of BBW systems, the main focus of this document is on the current state of the art systems.

A-5A Wheels, Brakes and Skid Controls Committee

Braking Requirements for Optimizing Autonomous Emergency Braking Performance

2019-01-212709/15/2019

Vehicle technology new developments have contributed to improve vehicle structural performance and therefore passive protection, but also the inclusion of electronic control units has provided new opportunities to expand active safety systems. This is the case for systems like anti-lock braking systems (ABS), electronic stability control (ESC) and brake assist (BA) among others. A more advanced generation of active systems includes sensorial units that monitor vehicle’s surrounding and detect potential hazards, such as an imminent collision, and performs an automatically and commanded emergency braking to lessen or mitigate the consequences of the impending accident. For this latest system, the so-called autonomous emergency braking (AEB), various consumer testing protocols, such as Euro NCAP protocols [1], propose and periodically update test catalogues in order to evaluate the performance of such systems and later to inform potential consumers. The aim of this study is to investigate

Esquer Molina, Álvaro, Bargallo, Jordi

Prediction and Control of Response Time of the Semitrailer Air Braking System

05/09/2019

The response time of the air braking system is the main parameter affecting the longitudinal braking distance of vehicles. In this article, in order to predict and control the response time of the braking system of semitrailers, an AMESim model of the semitrailer braking system involving the relay emergency valve (REV) and chambers was established on the basis of analyzing systematically the working characteristics of the braking system in different braking stages: feedback braking, relay braking, and emergency braking. A semitrailer braking test bench including the brake test circuit and data acquisition system was built to verify the model with typical maneuver. For further evaluating the semitrailer braking response time, an experiment under different control pressures was carried out. Experimental results revealed the necessity of controlling the response time. As a result, a braking pressure compensation system was designed through adding intake and exhaust solenoid valves to the

He, Ren, Xu, Chang

Influence Mechanism of Electromechanical Parameters on Transient Vibration of Electric Wheel System

2019-01-046204/02/2019

Electric wheel systems of in-wheel motor driven vehicles consist of the motor controller, in-wheel motor and tire-suspension assembly. The coupling between the electromagnetic excitation and elastic structure gives rise to electromechanical dynamic issues. As for the structural layout of the electric wheel system, the driving motor is directly connected to the wheel without torsion dampers or transmission in the driveline, thus making the electric wheel structure a weak damping system. Moreover, the driving torque of electric wheel can change rapidly in various conditions of vehicle. As a result, the transient vibration problem becomes one of the key electromechanical dynamic issues in the electric wheel system. To investigate this problem, the electromechanical coupling model of the electric wheel system is established first. Then the transient responses of the electric wheel under abrupt changes of the driving torque are simulated. The results indicate that the tire mainly suffers

Feng, Zhaoyang, Zuo, Shuguang, Mao, Yu

Development of Parametrically Integrated Software Platform for Passenger Car Brake System

2019-01-123104/02/2019

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

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

Regenerative Braking Pedal Decoupling Control for Hydraulic Brake System Equipped with an Electro-Mechanical Brake Booster

2019-01-110804/02/2019

Electrification and intelligence are the important development directions of vehicle techniques. The Electro-Mechanical Brake Booster (Ebooster) as a brake booster which is powered by a motor, can be used to replace the traditional vacuum booster. Ebooster not only improves the intelligence level of vehicle braking and significantly improves the braking performance, but also adapts to the application in new energy vehicles and facilitates coordinated regenerative braking. However, Ebooster cannot complete pedal decoupling independently. It needs to cooperate with other components to realize pedal decoupling. In this paper, a pedal decoupling control algorithm for regenerative brake, which is based on the coordination control of Ebooster and ESP, is proposed. First, regenerative braking strategy is designed to distribute the hydraulic brake force and regenerative braking force. Then, the coordinated control strategy of Ebooster and ESP is proposed, and the decoupling of brake pedal and

Zhao, Jian, Hu, Zhiqiang, Zhu, Bing

Development and Control of Four-Wheel Independent Driving and Modular Steering Electric Vehicles for Improved Maneuverability Limits

2019-01-045904/02/2019

Electric vehicles are capable of more flexible drivetrain configurations, such that driving dynamics of each wheel could be controlled independently to increase its stability and maneuverability bounds. We hereby propose a configuration consisting of four wheel independent driving and front and rear axle modular steering. The vehicle implements drive-by-wire technology, which means the control program running on vehicle control computer will have direct control authority of the vehicle under normal driving conditions, based on inputs of higher level systems such as human drivers and autonomous driving programs. Both the torque allocation on four wheels and the steering allocation on axles are completely independent on the mechanical hardware level, thus the vehicle is able to harness adverse contact conditions with confidence. A slip-aware model-free control method for torque allocation and steering is proposed and inspected in the paper, with digital model of a modified SUV simulated

Yang, Haoguang, Liu, Chen, Shi, Jiongming, Zheng, Gangtie

Information on Electric Brakes

AIR5937 (Current)02/15/2019

This SAE Aerospace Information Report (AIR) describes the design, operation, and attributes of electrical braking systems for both military and commercial aircraft. At this time, the document focuses only on brakes utilizing electromechanical actuators (EMAs), as that is the present state of the art. As such, the discussions herein assume that EMAs can simply replace the hydraulic actuation portion of typical brake system leaving things such as the wheel and heat sink unchanged. Furthermore, the document provides detail information from the perspective of brake system design and operation. The document also addresses failure modes, certification issues, and past development efforts. Details on the design and control of electric motors, gear train design, ball or roller screw selection are available in the reference documents and elsewhere, but are outside the scope of this document. Other all-electric technologies such as piezoelectric actuation or more exotic methods of applying drag

A-5A Wheels, Brakes and Skid Controls Committee

Challenges in High Current Measurements Using Magnetic Flux Concentrator and Hall Effect Current Sensor

2019-26-010601/09/2019

Accurate and safe current measurement in electric and hybrid electric vehicles impose several challenges in conventional shunt-based measurement technique due to presence of high voltages coupled with very high currents. In this paper, we have proposed a low cost and practical contactless current sensing method based upon Hall effect using magnetic flux concentrators and Hall effect sensor for DC current sensing. We aimed at developing a low power sensor having high sensitivity, and flexibility to accommodate in small size for DC currents ranging from ±100 amperes. In this paper, we have modelled the vital properties of the magnetic flux concentrator such as core dimension, air gap, core material and hysteresis. We achieved simulation results showing performance of sensor with respect to varying core material, air-gap, dimensions and temperature. Four different core materials with two geometries were created for benchmarking against simulations results. The modelling was performed in

Gambhir, Ameya, Newaskar, Abhishek, Desai, Tushar

Movement Prediction Hypotheses for Pedestrians and Trajectory Planning for Cooperative Driving Systems

12-02-01-000212/19/2018

It is a challenge to find a safe trajectory for automated vehicles in urban environments with pedestrians. The prediction of future movements with 100% certainty is impossible, if the intention is unknown. A Gaussian process approach is used to formulate future movement hypotheses of the pedestrian based on historical movements. A mixed integer linear programming (MILP) optimization approach is used for the trajectory planning of the vehicle. The collision probability between the ego-vehicle and pedestrian is used as constraints in the optimization. This approach is useful for cooperative vehicle systems, with historical movement data in a fixed urban environment (e.g., intersection) and the premise that pedestrians follow typical movement data.

Hartmann, Michael, Stolz, Michael, Watzenig, Daniel

Tire Side Force Characteristics with the Coupling Effect of Vertical Load and Inflation Pressure

10-03-01-000211/09/2018

The tire vertical load and inflation pressure have great influence on tire steady- and non-steady-state characteristics and, consequently, on the vehicle handling and stability. The objective of this article is to reveal the coupling effect of tire vertical load and inflation pressure on tire characteristics and then introduce an improved UniTire side force model including such coupling effect through experimental and theoretical analysis. First, the influence of the tire vertical load and inflation pressure on the tire characteristics is presented through experimental analysis. Second, the theoretical tire cornering stiffness and lateral relaxation length model are introduced to study the underlying mechanism of the coupling effect. Then, an improved UniTire side force model including the coupling effect of tire vertical load and inflation pressure is derived. Finally, the proposed improved UniTire side force model is validated through tire steady-state and transient data. The

Guo, Konghui, Chen, Ping, Xu, Nan, Yang, Chao, Li, Fei

Coordinated Control under Transitional Conditions in Hybrid Braking of Electric Vehicle

2018-01-186910/05/2018

In the hybrid brake system of electric vehicle, due to the limitation of the motor braking force when the motor is at high speed and the failure of the regenerative braking force when the motor is at low speed, there are three transitional conditions in hybrid braking: the hydraulic brake system intervenes the braking, the hydraulic brake system withdraws the braking and the regenerative braking force withdraws the braking. Due to the response speed of the hydraulic system is slower than that of the motor, there is a large braking impact (the derivative of braking deceleration) in the transitional conditions of hybrid braking, which deteriorates the smoothness and comfort in braking. Aiming at the impact caused by the poor cooperation between the hydraulic braking force and the motor braking force, a coordinated strategy of double closed-loop feedback and motor force correction is proposed in this paper. The double closed-loop feedback strategy relies on the motor force to compensate

Yu, Zhuoping, Shi, Biaofei, Xiong, Lu, Han, Wei

A Mathematical Model of the Braking Dynamics of a Car

2018-01-189310/05/2018

The braking efficiency of a vehicle is its most important operational property. However, in practice, researchers utilize simplistic physical-mathematical models for the process of vehicle braking that leads to accuracy reduction of these models predictions. The literature data show that the error in assessing braking efficiency can reach 30%. One of the main indicators of the efficiency of a braking system is deceleration. Most accurately, this value can be determined by experimental measurements. However, this is not always possible due to various technical reasons. The existing models typically ignore the impact of the car design and its speed on deceleration. They also either neglect air resistance completely or account only for its horizontal component. This paper presents an improved mathematical model written in the differential form that takes into account the impact of the lifting or downforce components of the aerodynamic forces. The proposed model accounts for the dependence

Saraiev, Olexii, Gorb, Yuliya

Inertia Calculation for Single-Ended Inertia-Dynamometer Testing

J2789_201809 (Historical)09/26/2018

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

Characterization of the brake system of a Formula SAE vehicle

2018-36-014809/03/2018

SAE Formula vehicles are required under extreme braking conditions during the race, where four-wheel braking is required. The brake assembly is composed of mechanical and hydraulic systems, which depending on the assembly of the components, can be subject to losses, causing a variation of the expected behavior. During braking situations, it is important to consider the load transfer in order to configure the braking distribution between the front and rear axles of the car with the best setup desired. The main objective of this work is to formulate a numerical model using the empirical data from the brake system of a SAE Formula vehicle to ensure that, after force is applied to the pedal, and the corresponding load is transferred to the front axle, the vehicle can lock the four wheels. Experimental data was acquired through static tests carried out on the bench and prototype vehicle, controlling the change of pressure and force between the front and rear axles through the balance bar

da Silva, Pedro Henrique Moraes, Idehara, Sérgio Junichi

A Nonlinear Slip Ratio Observer Based on ISS Method for Electric Vehicles

2018-01-055704/03/2018

Knowledge of the tire slip ratio can greatly improve vehicle longitudinal stability and its dynamic performance. Most conventional slip ratio observers were mainly designed based on input of non-driven wheel speed and estimated vehicle speed. However, they are not applicable for electric vehicles (EVs) with four in-wheel motors. Also conventional methods on speed estimation via integration of accelerometer signals can often lead to large offset by long-time integral calculation. Further, model uncertainties, including steady state error and unmodeled dynamics, are considered as additive disturbances, and may affect the stability of the system with estimated state error. This paper proposes a novel slip ratio observer based on input-to-state stability (ISS) method for electric vehicles with four-wheel independent driving motors. Instead of estimating vehicle speed, the proposed method employs the estimated error of motor torque as the correction output by taking the advantage of

Ren, Bingtao, Deng, Weiwen, Chen, Hong, Wang, Jinsong

Active Suspension Control of Electric Vehicle Driven by Switched Reluctance Motor Based on Vibration Absorbing Structure

2018-01-140104/03/2018

Active suspension control for in-wheel switched reluctance motor (SRM) driven electric vehicle with dynamic vibration absorber (DVA) based on robust H∞ control method is presented. The mounting of the electric drives on the wheels, known as in-wheel motor (IWM), results in an increase in the unsprung mass of the vehicle and a significant drop in the suspension ride performance and road holding stability. Structures with suspended shaftless direct drive motors have the potential to improve the road holding capability and ride performance. The quarter car active suspension model equipped with in-wheel SRM is established, in which the SRM stator serves as a dynamic vibration absorber. The in-wheel SRM is modelled using an analytical Fourier fitting method. The SRM airgap eccentricity is influenced by the road excitation and becomes time-varying such that a residual unbalanced radial force is induced. This is one of the major causes of SRM vibration. Current chopping control (CCC) and

Shao, Xinxin, Naghdy, Fazel, Du, Haiping

Pressure Control for Hydraulic Brake System Equipped with an Electro-Mechanical Brake Booster

2018-01-082904/03/2018

The Electro-Mechanical Brake Booster (Ebooster) is a critical component of the novel brake system for electric intelligent vehicles. It is independent of engine vacuum source, provides powerful active brake performance and can be combined with electric regenerative braking. In this paper, a brake control algorithm for hydraulic brake system equipped with an Ebooster is proposed. First, the configuration of the Ebooster is introduced and the system model including the permanent magnet synchronous motor (PMSM) and hydraulic brake system is established by Matlab/Simulink. Second, a Four-closed-loop algorithm is introduced for accurate active brake pressure control. Finally, according to the requirement of different brake force, series of simulations are carried out under active braking condition. The results show that the control algorithm introduced in this paper can ensure the brake hydraulic pressure tracking a target value precisely and show a good control performance.

Zhao, Jian, Hu, Zhiqiang, Zhu, Bing

The Influence of Autonomous Driving on Passive Vehicle Dynamics

2018-01-055104/03/2018

Traditional vehicles are designed to be inherently stable. This is typically obtained by imposing a large positive static margin (SM). The main drawbacks of this approach are the resulting understeering behavior of the vehicle and, often, a decrease in peak lateral grip due to oversized rear tire characteristics. On the other hand, a lower SM can cause a greater time delay in the vehicle’s response which hardens the control of a vehicle at limit handling for a human being. By introducing advanced autonomous driving features into future vehicles, the human factor can be excluded in limit handling manoeuvers (e.g., obstacle avoidance occurrences) and, consequently, the need for a high SM (i.e., high controllability for human drivers) can be avoided. Therefore, it could be possible to exploit the passive vehicle dynamics and enhance the performance, both in terms of peak grip and transient response. The goal of this article is to explore if a decrease in SM can lead to a performance

Liniger, Alex, Fainello, Marco, Danisi, Giacomo, Novi, Tommaso, Capitani, Renzo, Annicchiarico, Claudio

Analysis of Berla iVe Acquisitions of Vehicle Speed Data from Ford Sync Systems

2018-01-144204/03/2018

Many modern automobiles’ infotainment/navigation systems store vehicle telematics and user-supplied infotainment data. This data is useful in a wide variety of analyses but is not available through traditional OEM tools. The necessity to access the infotainment module data for forensic analysis can be satisfied by utilizing the Berla iVe system. Similar to CDR/EDR technology, Berla iVe is a hardware and software tool that is used to acquire and analyze stored automotive data. However, CDR/EDR systems are generally developed in partnership with manufacturers or OEM suppliers. Berla iVe is a privately developed forensic system analogous to traditional forensic tools used to interrogate computer hard drives and smartphones. The technology is privately developed and tested. The data is then parsed using recognized forensics practices. This research was focused on assessing the accuracy of speed data recorded in certain modules and the resulting translations reported by the Berla iVe system

Vandiver, Wesley, Anderson, Robert

Automotive Stability Enhancement Systems

J2564_201711 (Current)11/14/2017

The purpose of this SAE Information Report is to describe currently known automotive active stability enhancement systems, as well as identify common names which can be used to refer to the various systems and common features and functions of the various systems. The primary systems discussed are: a ABS - Antilock Brake Systems b TCS - Traction Control Systems c ESC - Electronic Stability Control The document is technical in nature and attempts to remain neutral regarding unique features that individual system or vehicle manufacturers may provide.

Vehicle Dynamics Standards Committee

Modeling and Optimization of Pneumatic Brake System for Commercial Vehicles by Model Based Design Approach

2017-01-249309/17/2017

Apart from being an active safety system the brake system represents an important aspect of the vehicle dynamics. The vehicle retardation and stopping distance completely depend upon the performance of brake system and the functionality of all components. However, the performance prediction of the entire system is a challenging task especially for a complex configuration such as multi-axial vehicle applications. Furthermore, due to its complexity most often the performance prediction by some methods is limited to static condition. Hence, it is very important to have equivalent mathematical models to predict all performance parameters for a given configuration in all different conditions This paper presents the adopted system modelling approach to model all the elements of the pneumatic brake system such as dual brake valve, relay valve, quick release valve, front and rear brake actuators, foundation brake etc. The results from these models such as transient pressure response during

Palanivelu, Sivakumar, Patil, Jeevan, Jindal, Ajit Kumar

Tuning of Brake Force Distribution for Pickup Truck Vehicle LSPV Brake System During Cornering Maneuver

2017-01-249109/17/2017

Automotive industry has led to constant production innovation among manufactures. This has resulted in the reduction of the life cycle of the design philosophies and design tools. One of the performance factors that have continues to challenge automotive designer is to design and fine tune the braking performance with low cost and short life cycle. Improvement in braking performance and vehicle stability can be achieved through the use of braking systems whosebrake force distribution is variable. Braking force distribution has an important and serious role in thevehicle stopping distance and stability. In this paper a new approach will be presented to achieve the braking forcedistribution strategy for articulated vehicles. For this purpose, the virtual optimization process has beenimplemented. This strategy, defined as an innovative braking force distribution strategy, is based on the wheel slips.The simulation results illustrate proposed strategy can significantly improve the vehicle

Anthonysamy, Baskar, Prasad, Arun Kumar, Shinde, Babasaheb

3D Printing Enables Customized Magnets

TBMG-2702206/01/2017

Polymer-bonded magnets are valuable for many sensor applications that require the production of unique and reproducible field profiles, not necessarily fields with the highest strength.

Active Safety Concept to Mitigate Slippery Road Conditions

2017-01-500205/30/2017

Antilock braking systems (ABS) are inherently limited by the static coefficient of friction (µ) between a vehicle’s tires and the road surface. This paper explores a unique active safety concept, Integrated Coefficient Enhancement (ICE), which works to improve ABS well beyond their present limits. The ICE concept was developed using a basic physics principle: to change µ between two surfaces, at least one of the surfaces must be altered in some way. By quickly deploying a specially designed tractive medium (TM) to aid in directional stability and braking, hazardous situations can be greatly mitigated. This paper describes the features and testing results of this TM and its aerodynamic-mechanical-electronic deployment apparatus. Under all slippery road conditions tested, the developed TM mitigated skidding, with improvements that ranged from 20% to several hundred percent, depending on conditions and deployment rates.

Skarie, James Bradley

Research on Vehicle Stability Control Strategy Based on Integrated-Electro-Hydraulic Brake System

2017-01-156503/28/2017

A vehicle dynamics stability control system based on integrated-electro-hydraulic brake (I-EHB) system with hierarchical control architecture and nonlinear control method is designed to improve the vehicle dynamics stability under extreme conditions in this paper. The I-EHB system is a novel brake-by-wire system, and is suitable to the development demands of intelligent vehicle technology and new energy vehicle technology. Four inlet valves and four outlet valves are added to the layout of a conventional four-channel hydraulic control unit. A permanent-magnet synchronous motor (PMSM) provides a stabilized high-pressure source in the master cylinder, and the four-channel hydraulic control unit ensures that the pressures in each wheel cylinder can be modulated separately at a high precision. Besides, the functions of Anti-lock Braking System, Traction Control System and Regenerative Braking System, Autonomous Emergency Braking can be integrated in this brake-by-wire system. A sliding

He, Xiangkun, Yang, Kaiming, Ji, Xuewu, Liu, Yahui, Deng, Weiwen

Longitudinal Vibration Analysis of Electric Wheel System in Starting Condition

2017-01-112603/28/2017

Due to coupling of in-wheel motor and wheel/tire, the electric wheel system of in-wheel motor driven vehicle is different from tire suspension system of internal combustion engine vehicle both in the excitation source and structural dynamics. Therefore emerging dynamic issues of electric wheel arouse attention. Longitudinal vibration problem of electric wheel system in starting condition is studied in this paper. Vector control system of permanent magnet synchronous hub motor considering dead-time effect of the inverter is primarily built. Then coupled longitudinal-torsional vibration model of electric wheel system is established based on rigid ring model and dynamic tire/road interface. Inherent characteristics of this model are further analyzed. The vibration responses of electric wheel system are simulated by combining electromagnetic torque and the vibration model. The results indicate that abrupt changes of driving torque will cause transient vibration of electric wheel system. To

Mao, Yu, Zuo, Shuguang, Wu, Xudong

Using Generic Tyre Parameters for Low Friction Surfaces in Full Vehicle Simulations

2017-01-150603/28/2017

An intervention of vehicle stability control systems is more likely on slippery surfaces, e.g. when the road is covered with snow or ice. Contrary to testing on dry asphalt, testing on such surfaces is restricted by weather and proving grounds. Another drawback in testing is the reproducibility of measurements, since the surface condition changes during the tests, and the vehicle reaction is more sensitive on slippery surface. For that, simulation enables a good pre-assessment of the control systems independent from testing conditions. Essential for this is a good knowledge about the contact between vehicle and road, meaning a good tyre model and a reasonable set of tyre model parameters. However, the low friction surface has a high variation in the friction coefficient. For instance, the available lateral acceleration on scraped ice could vary between 0.2 and 0.4 g within a day. These facts lead to the idea of using generic tyre parameters that vary in a certain range. Benefit would

Wiessalla, Johannes, Mao, Yiqin, Esser, Frank

Conversion of Drum Brake System to Disc Brake with CAE and CFD: Resulted in Optimized Brake Rotor Design and Improved Performance

2017-26-026101/10/2017

Paper explains conversion of existing drum brake system to disc brake system with complete digital validation at structural as well as thermal level to make sure First Time Right Design before physical part development. To provide leverage to quick design, modification and selection of brake system according to vehicle configuration, a virtual computational fluid dynamics (CFD) simulation process is developed and validated with test results. Temperature variation over brake drum and disc in internal standard braking cycle is measured virtually and correlated with test results. Also Fade testing criteria’s were considered during CFD analysis. This up gradation is must considering technology enhancement trend and safety in automotive segment. In current competitive market scenario and as per customer requirements, front disc brake module is becoming necessary not only for passenger segment but also for commercial segment vehicle. Brake system design is challenging task as it deals with

Anil Shah, Ashesh, Patidar, Ashok

Investigating the Parameterization of Dugoff Tire Model Using Experimental Tire-Ice Data

2016-01-803909/27/2016

Tire modeling plays an important role in the development of an Active Vehicle Safety System. As part of a larger project that aims at developing an integrated chassis control system, this study investigates the performance of a 19” all-season tire on ice for a sport utility vehicle. A design of experiment has been formulated to quantify the effect of operational parameters, specifically: wheel slip, normal load, and inflation pressure on the tire tractive performance. The experimental work was conducted on the Terramechanics Rig in the Advanced Vehicle Dynamics Laboratory at Virginia Tech. The paper investigates an approach for the parameterization of the Dugoff tire model based on the experimental data collected. Compared to other models, this model is attractive in terms of its simplicity, low number of parameters, and easy implementation for real-time applications. The relations correlating tire forces with slip ratios were identified by applying zero-phase filtering techniques to

He, Rui, Jimenez, Emilio, Sandu, Corina, Savitski, Dzmitry, Ivanov, Valentin, He, Rui, Jimenez, Emilio, Sandu, Corina

Novel Disc Brake System Leading towards Payload Increment and Maintenance Improvement

2016-01-193609/18/2016

Brake system for any vehicle plays an important role, as safety comes at highest level, also domestic and international safety norms for commercial vehicles are getting stringent. In current scenario of highly competitive commercial market, Payload advantage comes at peak level in customer demand list, also maintainability plays an important role to make sure least vehicle downtime, linked to customer profitability. Finally, if product has less complexity (reducing no. of parts), then it will provide add on benefit to any organization. Considering these customer oriented perspectives, mainly payload & maintenance, along with regulation compliance. We have proposed new Disc brake system for heavy duty commercial vehicle providing maximum payload benefit, along with enhancement in maintainability. It has also enhanced performance and meeting all legislative criteria at vehicle level.

Anil Shah, Ashesh, Raj, Kshitiz

Stop Lamps and Front- and Rear-Turn Signal Lamps for Use on Motor Vehicles 2032 mm or More in Overall Width

J2261_201607-TEST-REC (Current)07/20/2016

This SAE Standard provides test procedures, requirements, and guidelines for stop lamps and turn signal lamps intended for use on vehicles 2032 mm or more in overall width. Stop lamps and front- and rear-turn signal lamps conforming to the requirements of this document may be used on vehicles less than 2032 mm in overall width.

Stop Lamps and Front- and Rear-Turn Signal Lamps for Use on Motor Vehicles 2032 mm or More in Overall Width

J2261_201607 (Current)

07/20/2016

This SAE Standard provides test procedures, requirements, and guidelines for stop lamps and turn signal lamps intended for use on vehicles 2032 mm or more in overall width. Stop lamps and front- and rear-turn signal lamps conforming to the requirements of this document may be used on vehicles less than 2032 mm in overall width.

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