Browse Topic: Anti-lock braking (ABS)

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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.
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
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 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
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
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
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
Designing a Next Generation Trailer Braking System2021-01-126810/11/2021
Passenger vehicles have made astounding technological leaps in recent years. Unfortunately, little of that progress has trickled down to other segments of the transportation industry leaving opportunities for massive gains in safety and performance. In particular, the electric drum brakes on most consumer trailers differ little from those on trailers over 70 years ago. Careful examination of current production passenger vehicle hardware and trailering provided the opportunity to produce a design and test vehicle for a plausible, practical, and performant trailer braking system for the future. This study equips the trailer with high control frequency antilock braking and dynamic torque distribution through use of passenger vehicle grade apply hardware. Combining an electrically boosted one-box brake actuator with a complement of sensors allows one to leverage existing brake and chassis controls to produce high performance with minimal controls changes and off the shelf hardware in the
Reini, Steven, Spry, Douglas, Marmara, Stacey, Brinkman, Todd
Modeling Rack Force for Steering Maneuvers in a Stationary Vehicle2021-01-128710/11/2021
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 DefinitionJ1698/1A_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
Variability Analysis of FMVSS-121 Air Brake Systems: 60-mi/hr Service Brake System Performance Data for Truck Tractors2020-01-164010/05/2020
In support of the Federal Motor Carrier Safety Administration’s (FMCSA’s) ongoing interest in connected and automated commercial vehicles, this report summarizes analyses conducted to quantify variability in stopping distance tests conducted on commercial truck tractors. The data used were retrieved from tests performed under the controlled conditions specified for FMVSS-121 air brake system compliance testing. The report explores factors affecting the variability of the service brake stopping distance as defined by 49 CFR 571.121, S5.3.1 Stopping Distance—trucks and buses stopping distance. Variables examined in this analysis include brake type, weight, wheelbase, and tractor antilock braking system (ABS). This analysis uses existing test data collected between 2010 and 2019. Several of the examined parameters affected both tractor stopping distance and stopping distance variability. First, the average stopping distance for disc/disc brakes was shorter than either drum/drum or disc
Lascurain, Mary Beth, Franzese, Oscar, Siekmann, Adam
Research on Compensation Redundancy Control for Basic Force Boosting Failure of Electro-Booster Brake System2020-01-021604/14/2020
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
Integrated Regenerative Braking System and Anti-Lock Braking System for Hybrid Electric Vehicles & Battery Electric Vehicles2020-01-084604/14/2020
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 Method2020-01-056304/14/2020
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
Gokcek, Cevat
New Integrated Vehicle Dynamics Control System Based on the Coordination of AFS, DYC, and ED for Improvements in Vehicle Handling and Stability10-04-02-000901/27/2020
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 brake2019-36-002001/13/2020
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 Vehicles2019-36-001901/13/2020
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 Optimization2019-01-508911/19/2019
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 Technology2019-01-503811/04/2019
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 SystemsAIR5372A (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 Performance2019-01-212709/15/2019
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 System02-12-02-001105/09/2019
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
Reconstructing Vehicle Dynamics from On-Board Event Data2019-01-063204/02/2019
Modern vehicles record dynamic data from a number of on-board sensors for events that could precede a crash. These data can be used to reconstruct the behavior of a vehicle, although the accuracy of these reconstructions has not yet been quantified. Here, we evaluated various methods of reconstructing the vehicle kinematics of a 2017 and a 2018 Toyota Corolla based on Vehicle Control History (VCH) data from overlapping events generated by the pre-collision system (PCS), sudden braking (SB) and anti-lock brake (ABS) activation. The vehicles were driven towards a stationary target at 32-64 km/h (20-40 mph) and then after the pre-collision alarm sounded the vehicle was steered sharply right or left and braked rapidly to rest. VCH data for PCS event were recorded at 2 Hz and for the sudden braking and ABS activation events at 6.7 Hz. The steering wheel angle and the vehicle’s longitudinal acceleration, lateral acceleration, and angular rate data were extracted and used to predict the
Tsuge, Brandon, Yang, Mike, Flynn, Thomas, Xing, Peter, Lawrence, Jonathan, Heinrichs, Bradley, Siegmund, Gunter
Influence Mechanism of Electromechanical Parameters on Transient Vibration of Electric Wheel System2019-01-046204/02/2019
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 System2019-01-123104/02/2019
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 Booster2019-01-110804/02/2019
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 Limits2019-01-045904/02/2019
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 BrakesAIR5937 (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 Sensor2019-26-010601/09/2019
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 Systems12-02-01-000212/19/2018
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 Pressure10-03-01-000211/09/2018
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
Open-Loop Characteristics Analysis and Control of High Speed On-Off Valve2018-01-186810/05/2018
In the process of ABS control, the Anti-lock braking system (ABS) of the vehicle adjusts the wheel cylinder brake pressure through the hydraulic actuator so as to control the movement of the wheel. The high-speed on-off valve (HSV) is the key components of the Anti-lock braking system. HSV affects the performance of the hydraulic actuator and the valve response characteristics affects the Anti-lock braking system pressure response as well as braking effect. In this paper, the electromagnetic field theory and flow field theory of HSV are analyzed, and simulation analysis of electromagnetic field characteristics of HSV is done by ANSYS. Combined with the ANSYS analysis results, a precise physical model of HSV is constructed in AMESim. Meanwhile, the valve response characteristics are analyzed. Moreover, the influence of different wheel cylinder diameter and PWM carrier frequency on hydraulic braking force characteristics are analyzed. The open-loop control methods of hydraulic braking
Zhuo, Guirong, Shen, Huadong, Xue, Ruonan, Wu, Shenchen
Coordinated Control under Transitional Conditions in Hybrid Braking of Electric Vehicle2018-01-186910/05/2018
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 Car2018-01-189310/05/2018
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 TestingJ2789_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 vehicle2018-36-014809/03/2018
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
The Influence of Autonomous Driving on Passive Vehicle Dynamics2018-01-055104/03/2018
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
Novi, Tommaso, Liniger, Alex, Capitani, Renzo, Fainello, Marco, Danisi, Giacomo, Annicchiarico, Claudio
Analysis of Berla iVe Acquisitions of Vehicle Speed Data from Ford Sync Systems2018-01-144204/03/2018
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
Travelling Resistance Estimation and Sandy Road Identification for SUVs2018-01-057804/03/2018
The mechanical properties of sandy road are quite different from those of hard surface road. For vehicle control systems such as EMS (engine management system), TCU (transmission control unit) and ABS (antilock brake system), the strategies and parameters set for solid surface road are not optimal for driving on sandy road. It is an effective way to improve the mobility of all-terrain vehicles by identifying sandy road online and shifting the control strategies and parameters of control systems to sandy sets. In this paper, a sandy road identification algorithm for SUVs is proposed. Firstly, the vehicle signals, such as engine torque and speed, gear position, wheel and vehicle speed, are acquired from EMS, TCU and ESP (electronic stability program) through CAN (controller area network) bus respectively. Based on the information and longitudinal force equilibrium equation, the travelling resistance of vehicle is estimated. The hydraulic torque converter is divided into several parts to
Wu, Weixiang, Zhang, Jian, Zhao, Jian, Zhu, Bing
A Nonlinear Slip Ratio Observer Based on ISS Method for Electric Vehicles2018-01-055704/03/2018
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
A Comparison of Motorcycle Braking Performance with and without Anti-Lock Braking on Dry Surfaces2018-01-052004/03/2018
This paper analyzes motorcycle braking characteristics during stops at various speeds on a dry, asphalt surface with and without the use of the anti-lock brake system (ABS). To characterize the braking performance of the motorcycle, threshold brake stops were performed on a motorcycle of the superbike category at various speed increments. Motorcycle and brake system outputs consisting of brake pressures, wheel speeds, accelerations and yaw rates were measured and analyzed to highlight the different characteristics between a motorcycle with an integrated anti-lock brake system and multiple anti-lock brake system rider modes. Three different brake input strategies were used to brake the motorcycle; a front only brake application, a front and rear brake application, and a rear only brake application. The anti-lock brake system rider modes consist of a sport setting, a race setting and a setting that deactivates the anti-lock brake system. Each of the rider modes are tailored to the road
Dinges, Jeffrey, Hoover, Todd
Active Suspension Control of Electric Vehicle Driven by Switched Reluctance Motor Based on Vibration Absorbing Structure2018-01-140104/03/2018
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 Booster2018-01-082904/03/2018
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
Automotive Stability Enhancement SystemsJ2564_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
Performance Improvement of Regulator Rectifier for 2-Wheeler Engine with Respect to Upcoming Stringent Regulations in Emerging Market2017-01-242510/08/2017
On two wheelers, magneto/alternator generates either single/three phase AC power and Regulator Rectifier Unit (RRU) does regulated rectification to charge the battery. In order to face the requirements of 2-wheeler engine with respect to upcoming stringent regulations like electronic fuel injection (EFI), anti-lock braking system (ABS), automatic headlamp on (AHO) in emerging markets like India; vehicles demand more electrical power from batteries. This demands higher power from alternator and consequently from RRU. Requirement of higher output power presents challenges on regulator rectifier unit in terms of size, power dissipation management and reliability. In this paper, improved performance of MOSFET based RRU is discussed in comparison to Silicon Controlled Rectifier (SCR) based RRU. The motivation/benefits of MOSFET based design is described along with the thermal behavior and temperature coefficient performance of RRU with test results. The second topic discussed is how the
Verma, Ramit, R Ugale, Ramdas
Pressure Following Strategy for Conventional Braking Control Applied to a HIL Test Bench2017-01-249609/17/2017
Brake systems represent important components for passenger cars since they are strictly related to vehicle safety: Anti-lock Braking Systems (ABS) and Electronic Stability Control (ESC) are the most well-known examples. The paper is focused on the characterization of the braking hydraulic plant and on the design of a pressure following control strategy. This strategy is aimed at pursuing performances and/or comfort objectives beyond the typical safety task. The low-level logic (focus of the paper) consists of a Feedforward and Proportional Integral controller. A Hardware In the Loop (HIL) braking test bench is adopted for pressure controller validation by providing some realistic reference pressure histories evaluated by a high-level controller. Results prove that innovative control strategies can be applied to conventional braking systems for achieving targets not limited to braking issues, i.e., comfort or NVH tasks.
Galvagno, Enrico, Tota, Antonio, Vigliani, Alessandro, Velardocchia, Mauro
Longitudinal and Lateral Dynamics Evaluation of an Anti-Lock Braking System for Trail Snowmobiles2017-01-251209/17/2017
Anti-lock braking systems are one of the most important safety systems for wheeled vehicles. They reduce the braking distance and, most importantly, help the user maintain controllability and steerability of the vehicle. This paper extends and adapts the concept of Anti-lock braking systems to tracked vehicles, specifically to snowmobiles. Snowmobiles are an interesting development platform for two main reasons: 1) track dynamics, despite being analogous to tire dynamics, present important differences that help understanding the features of the control algorithm and 2) snowmobiles are simple and rugged vehicles with a limited set of sensors, making the design of an effective control system challenging. The paper designs a track-deceleration based ABS algorithm and tests it both in straight riding and cornering. The analysis shows that, on snowmobiles, Anti-lock braking systems have negligible advantages in term of stopping distance, but are beneficial in terms of steerability and
Corno, Matteo, Roselli, Federico, Onesto, Luca, Savaresi, Sergio, Molinaro, Frank, Graves, Eric, Doubek, Andrew
Tuning of Brake Force Distribution for Pickup Truck Vehicle LSPV Brake System During Cornering Maneuver2017-01-249109/17/2017
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
Modeling and Optimization of Pneumatic Brake System for Commercial Vehicles by Model Based Design Approach2017-01-249309/17/2017
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
3D Printing Enables Customized MagnetsTBMG-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.
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