Browse Topic: Anti-lock braking (ABS)

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Research on Electro-Hydraulic Composite Braking Control Strategy for Four-Axle Electric-Drive Special Vehicles02-20-01-00059/22/2026
Four-axle electric-drive special vehicles are often deployed to execute complex tasks under extreme operating conditions. Their harsh working environments, stringent dynamic-response requirements, and high energy demand for mobility impose higher requirements on both the energy-regeneration efficiency and braking safety of the braking system. To address these issues, this article proposes an electro-hydraulic composite braking control strategy for four-axle electric-drive special vehicles. First, a braking axle-load transfer model for the four-axle electric-drive special vehicle is established, enabling axle-to-axle braking force distribution based on axle loads. Second, considering the motor torque characteristics and battery charging characteristics and by establishing an anti-lock braking prediction model, an electro-hydraulic composite braking torque allocation strategy with safety-range constraints on motor braking torque is designed. Then, to enhance vehicle safety during emergency braking, an adaptive super-twisting sliding-mode variable-structure anti-lock braking system (ABS) controller is proposed, and based on this ABS controller, an emergency braking control strategy is developed in which the motor braking torque is pre-reduced to within a safe range, with motor-dominant and hydraulic auxiliary modulation. Finally, simulation and real-vehicle tests demonstrate that the proposed electro-hydraulic composite braking control strategy improves the motor braking energy recovery rate under service braking conditions, reduces the braking distance, and enhances braking safety under emergency braking conditions.
Jin, Liqiang, Peng, Jinxin, Ke, Yuan, Peng, Silun, Li, Jianhua, Xiao, Feng
Electro-Hydraulic Brake-by-Wire and Off-the-Shelf ABS Integration: Control Design and Hardware in the Loop Validation2026-01-07959/14/2026
This work presents the design of a control logic for an electro-hydraulic brake-by-wire in series with an off-the-shelf ABS unit for motorsport applications. Validation is performed through hardware-in-the-loop testing with a complete hydraulic layout, including the brake-by-wire actuator, the ABS module, and brake calipers. State of the art electro hydraulic brake-by-wire systems are increasingly adopted in top level motorsport and are now transitioning to high performance road vehicles, in combination with ABS and ESC. However, due to motorsport regulations, racing brake-by-wire systems do not incorporate ABS functionality. To combine the performance of motorsport grade actuators with the ease of use required for non professional drivers, a series configuration between brake-by-wire and ABS represents a natural solution. This architecture is also relevant for future road vehicle applications, offering additional redundancy for autonomous driving ready systems. A dedicated hardware-in-the-loop test rig has been developed to perform experimental testing of the complete brake system. Wheel dynamics are simulated in real-time using a single-axle vehicle model, and wheel speed signals are reproduced via a sensor emulator. Preliminary tests show that the original pressure-based brake-by-wire control strategy exhibits poor performance during ABS activation, as ABS operation significantly alters system behavior. To address this issue, an improved control strategy is proposed, introducing a dedicated control mode activated during ABS operation, with a smooth transition back to nominal control once ABS activity ceases. Experimental results demonstrate that the proposed strategy maintains closed-loop stability, avoids excessive pressure oscillations and piston end stop conditions, and, most important, does not interfere with ABS operation. Overall braking performance is fully preserved.
Milivinti, Massimiliano, Gimondi, Alex, Gobbi, Massimiliano, Cantoni, Carlo
Modeling Brake Torque Hysteresis for Chassis Controls Hardware in the Loop Simulation2026-01-08249/14/2026
It is hardly a new trend for on road, vehicle intensive tuning and testing of chassis control features such as Anti-Lock Brakes, Traction Control, and Electronic Stability Control to move away from vehicle testing and towards non-vehicle test platforms such as Hardware-In the Loop (HIL) simulations and even further into pure math-based simulations. However, a significant acceleration of these activities has been occurring recently in the automotive industry, reducing or eliminating calibration time on vehicles and amplifying the demand for highly representative, non-vehicle test platforms to validate and even calibrate chassis controls features. In current state of the art HIL simulation, the input (brake pressure) to output (brake torque) of each wheel brake in a vehicle’s brake system is modeled relatively simplistically, including at most pressure and brake temperature sensitivities, usually in lookup table form. Each brake corner contains over 20 different friction interfaces, which in turn can cause hysteretic behavior (a difference in the output for a given input, depending on whether the brake is applying or releasing against the hysteretic friction). This hysteresis is neglected in most state of the art HIL simulations. Past studies by General Motors have shown that the importance of brake corner hysteresis in vehicle level, customer facing performance of chassis controls features can range from inconsequential to significant. With the crescendo-ing demand for high quality non-vehicle based methods for assessing chassis controls function, the effect of hysteresis is no longer academic. The present study starts with HIL based simulations, establishing the effect of brake corner hysteresis on one of the most visible chassis controls behaviors. An inertia dynamometer-based test was developed to exercises the subject brake corners through apply and release cycles, thus enabling any hysteretic behavior to be observed and characterized. Machine Learning models were trained with these data to represent brake corner hysteretic behavior and then deployed into an HIL simulation rig. The impact of these models – representing brake corner hysteretic behavior – was characterized for straight line stopping distance on low, medium, and high coefficient road surfaces.
Antanaitis, David, Ridenour, Nick, Miller, Bryan, Karnjate, Timothy
Application of a Novel Noise-Reduction Material to Reduce Squeak Noise in Automotive Instrument Panels2026-01-50657/31/2026
In recent years, driven by increasing consumer demands for vehicle aesthetics and perceived quality, automotive instrument panels (IPs) have extensively adopted materials with poor friction compatibility, such as chrome-plated strips and synthetic leather. Concurrently, the engineering requirement for tighter matching gaps between components has significantly escalated the risk of friction noise. Traditional mitigation strategies—such as material substitution, increasing gap clearances, or applying physical isolation—are often difficult to implement due to design constraints, rendering the IP a critical high-risk zone for abnormal noise. This paper proposes a methodology to mitigate squeak noise between polycarbonate/acrylonitrile butadiene styrene (PC/ABS) and its mating counterparts by modifying the viscoelastic characteristics of the PC/ABS base material through the addition of a specialized polymer. Furthermore, a neural network model was established to objectively determine the noise compatibility of these materials. Evaluations of the material compatibility before and after modification demonstrate that adding a specific proportion of the special polymer to PC/ABS significantly improves its friction compatibility with materials such as polyvinyl chloride (PVC) skin. The efficacy of this solution was confirmed through application and verification in a mass-production vehicle.
Liu, Zubin, Cao, Chunyu, Hou, Hangsheng
Factors that Influence the Determination of Adhesion Utilization of the ABS in Commercial Vehicles: A Case Study2026-36-03077/30/2026
The anti-lock braking system (ABS) plays a fundamental role in preventing wheel lockup and preserving vehicle steerability and stability during braking. In Brazil, ABS is mandatory for commercial vehicles since 2014, following CONTRAN Resolution 380/11, with the objective of improving traffic safety and reducing road accidents. The performance of an ABS is directly influenced by the characteristics of the vehicle’s braking system, including its pneumatic architecture and mechanical component sizing, which determine brake-force distribution and the frequency of ABS intervention. Regardless of these characteristics, developers must ensure that ABS efficiency complies with applicable regulatory requirements. For performance assessment, NBR 10966 Part 6 establishes procedures for measuring and calculating the adhesion utilization of ABS. Represented by the letter epsilon (ε), adhesion utilization quantifies the relationship between the braking performance achieved with ABS active and that corresponding to the vehicle’s maximum braking capacity without wheel slip. This metric provides an indirect evaluation of system efficiency. This work presents a case study conducted during the development of the ABS for a medium-heavy truck equipped with more than two axles. The study consisted of the analysis of results obtained following the adhesion utilization determination methodology defined in NBR 10966 Part 6, and of the evaluation of its applicability to multi-axle vehicles. Despite the braking system and vehicle configuration meeting all minimum static and dynamic performance requirements, the measured adhesion utilization fell below expectations. This outcome prompted a detailed investigation of both the measurement approach used for this vehicle category and the factors affecting the tire–road friction coefficient, which are independent of the braking system itself. The analysis indicated potential improvements in the test methodology for vehicles with more than two axles and highlighted the significant influence of test-track surface conditions on the results obtained.
Dias, Eduardo Miranda, Rudek, Claudemir, Travaglia, Carlos Abílio Passos
Development and Validation of a Braking Simulation Model Applied to a 6x2 Vehicle in Compliance with NBR 10966-22026-36-03187/30/2026
This study presents a comparative analysis of the braking performance of a heavy commercial vehicle under in-gear and out-of- gear conditions, combining experimental tests conducted at 60 km/h with high-fidelity computational simulation. The numerical model incorporates real engine torque, power, and motoring/braking curves, full brake system parameters, dynamic load transfer, tire–road friction characteristics, and ABS actuation. Simulation results were validated against experimental MFDD and stopping distance measurements. The simulation demonstrated a high correlation with the experimental MFDD values (5.3 vs. 5.36 m/s2 in the in-gear condition and 5.6 vs. 5.37 m/s2 in the out-of-gear condition), confirming the robustness of the model. Differences in stopping distance were attributed primarily to the real-world behavior of the ABS and to variability in the road surface friction coefficient. The study concludes that braking with the vehicle in gear provides improved longitudinal stability due to the resistive contribution of engine drag torque, which also reduces the thermal load on the service brakes. Overall, the results reinforce the essential role of simulation as a development, optimization, and certification tool for brake systems.
Junior, Getulio Soares, Canale, Antônio Carlos, de Oliveira, Sergio Henrique Fidelis, Pizzi, Rafael Fortuna
Impacts of Automation and Electrification Trends on Pneumatic Braking Systems of Commercial Vehicles2026-36-03417/30/2026
Historically, the demand for advanced technology, efficiency, and safety has been a primary driving force in the evolution of commercial vehicles, particularly with respect to braking systems. More recently, the increasing levels of vehicle autonomy and electrification have emerged as irreversible trends, significantly accelerating the development of new functionalities and innovative electrical/electronic [E/E] architectures. These advancements are essentially focused on performance optimization, risk mitigation, and enhanced system reliability through the application of functional safety and cybersecurity standards, thereby shaping the current landscape of braking system design. From an efficiency standpoint, braking systems with higher levels of electronic content, functional integration – included with regenerative braking systems - and harmonization have been developed to improve energy efficiency and support global scalability. Concurrently, new system configurations are continuously being introduced to enhance vehicle safety and advanced driver assistance capabilities, in alignment with evolving regulatory requirements and market expectations. This paper evaluates the impacts of automation and electrification on commercial vehicle pneumatic braking systems, focusing on Anti-lock Braking Systems [ABS], Electronic Braking Systems [EBS] and air management platforms. It provides a technical overview of both architectures, assessing their capabilities to meet modern requirements such as integration with advanced vehicle architecture, regenerative braking for electrified applications, and Advanced Driver-Assistance Systems [ADAS] support. The study details the evolution of air management systems, with emphasis on electrified vehicles, including key functions such as air compressor charge control, Air Processing Unit [APU] desiccant regeneration, and electronic control strategies. Additionally, it examines key drivers of braking system evolution, braking system selection considering ADAS regulatory developments, Net Zero strategies, and automation trends. The paper further evaluates compliance with functional safety and cybersecurity standards and assesses the readiness of both platforms for emerging mobility concepts. Finally, it highlights the risks of deploying higher levels of autonomy in heavy-duty towing vehicles when operating with non- ABS semi-trailers, identifying this as a critical area for further investigation.
Guarenghi, Vinícius Mendes, Nicora, Fabio, Pizzi, Rafael Fortuna, Resende, Angelo Roberto Rodrigues, Pinto, Gustavo Laranjeira
A Study of Federal Motor Vehicle Safety Standard 126 and 136 Test Procedures on a Class 5 Vehicle2026-01-06164/7/2026
Federal Motor Vehicle Safety Standards (FMVSS) 126 and 136 are standards imposed on four of the eight recognized road vehicle classes in The United States. These standards make it mandatory for Electronic Stability Control modules (ESC) to be mounted to Class 1,2,7, and 8 vehicles. These modules strategically activate the vehicle brakes via the Antilock Brake System (ABS) to limit the recorded yaw rate and lateral displacement of a vehicle during an extreme cornering maneuver such as a sudden swerve to avoid an obstacle on the road. The two aforementioned FMVSS mandates also specify three different driving maneuvers that are conducted to profile and analyze ESC module performance. There is now an interest in creating a new FMVSS that makes ESC modules mandatory for Class 5 vehicles. The purpose of this paper is to analyze how one specific Class 5 vehicle’s ESC module performed when subjected to the two test procedures that correspond to FMVSS 126 and 136. As will be seen, the vehicle’s ESC performed quite well for the FMVSS 126 testing criteria and not as well with the FMVSS 136 testing criteria. The details of these results should both be considered if and when a new FMVSS ESC mandate is to be produced. To aide in the creation of such a mandate, additional experimental and simulation data will be necessary from other Class 5 vehicles. Simulated driving maneuvers with an accurate vehicle model will prove valuable in this pursuit. The results of such simulations will be discussed and the value that they bring will help to expedite the formation of the proposed FMVSS that covers these vehicles.
Cazares, Richard Isaac, Guenther, Dennis, Heydinger, Gary
Vehicle Deceleration Levels during Wet-to-Dry Transitions on an Asphalt Surface with a High Proportion of Aggregate2026-01-05424/7/2026
The braking performance of a vehicle at varying levels of road wetness is an important factor in collision reconstruction. Here we quantify the deceleration levels of two modern vehicles equipped with antilock brake systems (ABS) on a wetted asphalt surface with a high proportion of exposed, large-sized aggregates as the road naturally dried over time. We also compare our current results to prior tests on asphalt with a small proportion of small-sized aggregate. Two ABS-equipped vehicles were maximally braked on an asphalt road surface as the road naturally transitioned from a saturated wet state to a completely dry state. Road wetness was visually categorized from photographs taken during testing. Overall, we found that deceleration levels on wet asphalt were significantly less than deceleration levels on dry asphalt (average dry: 0.902g and 0.962g; average wet: 0.787g and 0.818g for the two vehicles). Within the wetness categories we used, there was either no significant difference or only a small significant difference between the three wettest categories (road surface >75% wet, 100% wet with a matte surface, and saturated with a glossy surface). Similarly, there were no significant differences between the two driest conditions (road surface <25% wet and completely dry). This pattern of findings is similar to our prior tests, although the absolute deceleration levels in the current study were 0.028g lower on dry asphalt and 0.076g lower on wet asphalt than in our prior study on asphalt with a lower proportion of smaller-sized aggregate but a similar mean texture depth. These findings provide two important insights: first, the current data support our prior proposition of a readily identifiable boundary in ABS deceleration levels between dry and wet road surfaces, and second, ABS deceleration levels measured using the current test methods may be more sensitive to changes in road surface friction than the standardized measure of road surface macrotexture we used here.
Ahrens, Matthew, Arnold, Nikolas, Miller, Ian, Siegmund, Gunter P.
The Effect of Tire Tread Depth on Antilock-Brake System (ABS) Decelerations on Dry and Wet Asphalt and Concrete Road Surfaces2026-01-05494/7/2026
The effect of tire tread depth on the deceleration performance of anti-lock brake systems (ABS) in newer vehicles is not well studied. A single sport-utility vehicle (SUV) was used to perform a series of 216 ABS-engaged braking tests on dry and wet asphalt and concrete surfaces using six sets of four tires with tread depths varying from 0.8 mm (1/32″) to 7.1 mm (9/32″). Vehicle speed and deceleration as a function of time were calculated from 5th-wheel displacement data sampled at 200 Hz. Braking tests were initially conducted on a dry surface, after which a water truck distributed water onto the road to create a wet condition and additional tests of each tire set were conducted. Overall, average deceleration levels did not vary significantly across the tires sets with tread depths from 7.1 mm (9/32″) down to 2.4 mm (3/32″) for both road surfaces in both dry and wet conditions. Compared to the deceleration levels at these larger tread depths, dry deceleration levels were greater for tread depths of 0.8 mm (1/32″) and 1.8 mm (2/32″) on both asphalt and concrete, and wet deceleration levels were lower for tread depths of 0.8 mm (1/32″) on both asphalt and concrete. These findings provide a source for analysts to estimate how tread depth affects deceleration for ABS-equipped vehicles.
Miller, Ian, King, David, Siegmund, Gunter P.
Benchmark of Conventional and By-Wire Brake System Layouts for Electric Vehicle Applications by Numerical Simulations2026-01-50082/3/2026
The recently increasing global concern about sustainability and greenhouse gas emission reduction has boosted the diffusion of electric vehicles. Research on this topic mainly focuses on either re-designing or adapting most conventional vehicle subsystems, especially the propulsion motor and the braking components. In this context, the present work aims to model, analyze, and compare three-braking system layouts design alternatives focusing on their contribution to vehicle performance and efficiency: a commercial vacuum-boosted hydraulic braking system, a commercial integrated electrohydraulic braking system, and a concept distributed electrohydraulic brake system. Braking systems performance are evaluated by simulating key maneuvers adopting a full model of a battery electric vehicle (BEV), which includes all relevant components like tires, and powertrain dynamics, which is validated against real-world data. Implementation and integration of the first two systems are discussed, followed by the design and detailed modeling of the third, which includes a control strategy for pressure modulation, including antilock braking system (ABS) and electronic stability control (ESC) functionalities. Once the simulation environment is set, simulations are performed and KPIs are defined to compare the three braking systems from both the performance and the energy consumption point of view. The results show that the distributed electrohydraulic system reduces the time to lock by 30.8%, the stopping distance by 5.89%, and the energy consumption by more than 50% in specific test cases compared to the analyzed vacuum-boosted system due to its distributed hardware and control architecture and power-on-demand operation.
Savi, Lorenzo, Garosio, Damiano, Floros, Dimosthenis, Vignati, Michele, Travagliati, Alessandro, Braghin, Francesco
Coordinated Control of DYC/ABS for Cornering Braking Based on Driver Intention2025-01-734012/31/2025
This paper proposes a DYC/ABS coordinated control strategy for cornering and braking based on driver intention. A hierarchical control structure is established, where the upper-level controller uses a vehicle dynamics model to calculate the additional yaw moment required by the DYC controller to track the desired yaw rate and sideslip angle, as well as the driver’s intended braking intensity. Taking multiple constraints into account, a quadratic programming algorithm is employed to optimize the distribution of braking forces among the four wheels. The lower-level ABS controller is designed with multiple thresholds and corresponding control phases to precisely regulate the hydraulic pressure of individual wheel cylinders. In emergency braking scenarios where ABS intervention may conflict with the upper-layer braking force allocation, a rule-based, stepwise diagonal pressure reduction compensation strategy is proposed. This strategy fully considers the influence of longitudinal and lateral forces of each wheel on the vehicle's yaw moment. By selectively reducing brake pressure, it generates an additional yaw moment to compensate for the negative impact of ABS on vehicle steerability, while ensuring a smooth pressure transition. The proposed strategy is validated on a Driver-in-the-Loop (DIL) simulation platform built using NI PXI, DSPACE, and external driver inputs such as the steering wheel and brake pedal. Under various driver braking intentions and cornering scenarios with high and low road adhesion, the strategy shows significant improvements in fulfilling driver braking demands and enhancing vehicle yaw stability compared to the non-optimized strategy.
Zou, Yan, Ma, Yao, Kong, Yan, Pei, Xiaofei
Wheel Speed Control for Corner Module ABS with Full Brake-By-Wire System2025-01-732212/31/2025
The electro-mechanical brake (EMB), with its continuous torque control characteristic, can enhance the performance of anti-lock braking control in intelligent chassis system. Therefore, in this study, a corner module anti-lock braking system (ABS) using EMB is proposed for intelligent chassis driven by in-wheel motors (IWMs). The corner module design can directly utilize the high-bandwidth speed signal of the IWM. This transforms traditional ABS wheel slip rate control into low-latency, high-bandwidth wheel speed tracking control under strong transient conditions. As a result, the control loop is simplified and signal transmission delay is reduced, which allows EMB to fully exploit its performance advantages. Additionally, this study proposes an Improved Higher-order Sliding Mode Control strategy with Super-Twisting Algorithm (IHSMC-STA) for wheel speed tracking control. The proposed strategy enhances the traditional first-order sliding mode exponential reaching law and integrates the Super-Twisting Algorithm to achieve high-precision and robust ABS control. Finally, experimental validation is conducted through both single-wheel ABS test bench and real vehicle testing. The results demonstrate that the proposed corner module ABS system achieves faster response and enhanced stability in anti-lock braking control under various road surface conditions, thereby confirming the effectiveness of the developed approach.
Chang, Cheng, Chu, Liang, Zhao, Di
Research on Wheel Slip Ratio Control for Electro-Mechanical Brake System: From PI to High-Order Sliding Mode Control2025-01-733212/31/2025
The electro-mechanical brake (EMB) system is a novel dry-type brake-by-wire system that features superior control performance and a compact structural design, effectively meeting the development demands of intelligent and electrified vehicles. However, current research on anti-lock braking system (ABS) primarily focuses on hydraulic brake system and mostly remains at the simulation and hardware-in-the-loop testing stages. Therefore, this paper validates the feasibility of slip ratio control based on EMB actuators through both simulation and real-vehicle experiments. First, this paper establishes an equivalent second-order response model for the closed-loop EMB control system through theoretical derivation and identifies the dynamic response characteristics of the EMB actuator via sinusoidal frequency sweep testing. Next, it compares two control strategies: one that uses the reference slip ratio as the direct control target, and another that uses reference wheel speed as the direct control target to indirectly regulate slip ratio. The latter effectively avoids the nonlinearities in slip ratio control caused by variations in vehicle speed. Based on reference wheel speed control, three types of slip ratio controllers were designed and derived: proportional-integral control (PI), integral sliding mode control (ISM), and super-twisting integral sliding mode control (STISM). Finally, simulation and real-vehicle tests on high-adhesion road surfaces verified that sliding mode slip ratio control based on reference wheel speed offers robustness, avoids the risks associated with overestimated controller gains, and improves the overall stability of the control system. In particular, the STISM, as a representative of high-order sliding mode control, effectively addresses the chattering issue present in traditional first-order sliding mode methods, offering enhanced braking safety and comfort.
Cheng, Yulin, Qiao, Le, Wang, Chenyu, Li, Congcong, Zhuo, Guirong, Wei, Wei
Predictive Control Applied to Antilock Braking Systems of Heavy Vehicles on Deformable Terrain2025-36-000412/18/2025
Antilock braking systems (ABS) are critical to ensuring vehicle safety, particularly in challenging off-road environments where the braking dynamics is highly complex. This study focuses on the development of an advanced ABS controller for heavy off-road vehicles to improve operational safety and reliability. For this purpose, a Model-based Predictive Control (MPC) is proposed. The predictive capabilities of MPC, which optimize control actions based on system dynamics and constraints, are highlighted as a key aspect of this approach. The controlled system is modeled and simulated using a quarter-car model and a deformable ground model, providing a realistic representation of off-road conditions. Comparative simulations are conducted to evaluate the performance of both controllers, focusing on their effectiveness in maintaining stability and improving braking efficiency.
Sawada, Fernando Satoshi, Santos, Luís Guilherme Cavalcante, Rodrigues, Gustavo Simão, Rossi Lopes, Elias Dias
Identification of Runway Friction Coefficient Using Extended Kalman Filter09-13-02-001212/11/2025
Aircraft operations during landing or takeoff depend strongly on runway surface conditions. Safe runway operations depend on the tire-to-runway frictional force and the drag offered by the aircraft. In the present research article, a methodology is developed to estimate the braking friction coefficient for varied runway conditions accurately in real-time. To this end, the extended Kalman filtering technique (EKF) is applied to sensor-measured data using the on-ground mathematical model of aircraft and wheel dynamics. The aircraft velocity and wheel angular velocity are formulated as system states, and the friction coefficient is estimated as an augmented state. The relation between the friction coefficient and wheel slip ratio is established using both simulated and actual ground roll data. Also, the technique is evaluated with the simulated data as well as real aircraft taxi data. The accuracy of friction estimation, with and without the measurement of normal reaction force on the landing gear, is analyzed using the simulated data. The friction coefficient vs slip ratio curve, derived from the empirical “Magic formula”, compares well with the estimated maximum tire-to-ground braking friction, and a shift in optimal slip is observed in actuality compared to the predictions. The brake disc friction coefficient is also estimated during the process since the brake torque measurements are not available in the actual data. The estimated friction coefficient, which represents the real characteristics of the runway, can be used to tune the control algorithms of the aircraft’s anti-skid brake management system for various runway conditions. While improvements in anti-skid efficiency alone may not directly prevent all runway excursions, accurate real-time friction estimation enhances the predictability and reliability of braking action, supporting safer operations under degraded or uncertain runway conditions. Moreover, the real-time estimation of tire-to-ground friction coefficient vs slip ratio curves can be used to develop adaptive control algorithms for the brake management system.
T.K., Khadeeja Nusrath, Singh, Jatinder
Measurement of Road Friction Coefficient with Strain at Tire Sidewall: Verification by Actual Vehicle Driving Experiments10-10-01-000511/20/2025
If road friction coefficient can be measured in a car driving, the performance of advanced driver-assistance systems (ADAS) such as antilock braking system (ABS) and automatic braking systems can be improved. Generally, ADAS uses information obtained from wheel speed sensors, acceleration sensors, and the like. However, it is difficult to measure accurately road friction coefficients with these sensors. Therefore, many studies measured road friction coefficients from strain or deformation in the bottom of a tire (tread), which is the only place to contact with a road surface. However, a sensor installed on the bottom of a tire is easy to peel or damage because greater deformation occurs locally on the bottom of a tire. Therefore, this study develops a method of measuring the road friction coefficient from the strain induced in a tire sidewall. If the tire sidewall can be used, stable measurement can be expected because the sidewall is harder to deform locally than the bottom of a tire. It has be previously confirmed that the triaxial direction loads acting on a ground contact surface of a tire and the strain induced in the tire sidewall have almost a linear relationship. By determining the experimental formulas about the relationship, we can measure road friction coefficient during car driving. This article describes the method to determine appropriate formulas with determining the optimal measurement condition of the strains induced in the tire sidewall and confirms the availability with actual driving experiments.
Higuchi, Masahiro, Tachiya, Hiroshi
Optimizing the Structural Finite Element Method based Process to Evaluate the Sustainable Human Accidental Sliding Load of Automobile Airvent Knob Design Made with Thermoplastic PC - ABS2025-28-028911/6/2025
The research work elaborated the structural integrity of airvent by skipping the assembly level snap fit finite element analysis of knob to reduce computational complexity of air vent knob sliding test post stopper. During assembly, the strain based mechanical breakage prediction of airvent sliding knob snaps is investigated in non-prestressed condition. The research work proposes a FEM based analysis approach to evaluate the mechanical breakage load of airvent knob assembly for accidental sliding load. This process skips the assembly level snap insertion load case along with silicone rubber pad compression which could serve as the prerequisite simulation. This prerequisite simulation is computationally expensive and complex to solve due to polymer plasticity and silicone rubber elastomer hyper-elasticity and moving frictional contacts between parts. If the accidental sliding load case without considering pre-tension on snaps is simulated, the load causing mechanical failure in the FEM based analysis is not correlating with experimental prototype samples breakage force values. The strain at break for composite, polycarbonate (PC) with acrylonitrile-butadiene-styrene (ABS) material used for knobs, is 100%. By considering the lower strain criteria of 5%, the analysis results and experimental testing results in terms of load causing mechanical breakage and breakage zones are co-related. To validate the established breakage strain criteria of 5%, another airvent knob design with same material of knob is considered for study. A good correlation is established between FEM approach and experimental testing. It is concluded from the outcomes of the FEM based analysis that the 5% strain as breakage criteria set for capturing knob strength for accidental sliding load case is efficient. The same process set can be utilized for developing more airvent knobs.
Shah, Viren, Miraje, Jitendra
Bolstering Driver Braking Confidence – Considerations for “Deceleration Adder” Technologies2025-01-03539/15/2025
Over the life of a typical vehicle (often estimated as 15 years or 300,00 km), an average driver can be expected to apply the brakes about 1.6 million times – almost 9 times per mile and over 290 times per day, and an “exuberant” driver can be expected to do this over 2.2 million times. Without question, the driver becomes accustomed to how the vehicle responds to braking control (and all of the normal variation around it), and even develops expectations for how it will respond the next time the brakes are employed. In the rare event of a failure or malfunction in the brake system resulting in an appreciably different vehicle response to the brake input, this can be surprising and even alarming to the driver, sometimes to the extent of causing hesitation in braking. Fortunately, with the rise of mechatronic braking actuators in the 1980’s and 1990’s paved the way for features such as “Driver Brake Assist” (which provides additional pressure beyond what the primary brake actuator can at the time) and “Panic Brake Assist” (which provides additional pressure beyond what the driver is requesting, when the brake apply rate is above a calibratable threshold) to be developed. These features used the new (at the time) brake actuator, the hydraulic pump in the anti-lock brake unit, to provide additional assist to the driver if needed. Vehicles of today will often have multiple actuators capable of providing deceleration, including a mechatronic (or vacuum) brake booster, regenerative braking, electric parking brake actuators, and in some cases a secondary brake module. With these added degrees of freedom, comes added opportunity to improve performance and therefore the driver’s confidence in the vehicle’s braking capability, but also added complexity. With actuators able to increase - depending on their installation - braking on the front axle, the rear axle, or both, and with the ability to suppress hydraulics via valve control to reduce pedal travel, important considerations for brake balance and vehicle stability arise, which must be balanced with straight line performance and brake feel. The present work briefly examines the history of “deceleration adders” (supplemental brake actuators used to improve performance in certain operating conditions such as system failures), draws from published information to establish a framework for the performance necessary to maintain the driver’s confidence, and discusses different actuator types and control strategies along with considerations for integrating them into the brake system.
Antanaitis, David
Research on Anti-Slip Traction Control for Aircraft Engine-off Towing System2025-01-82924/1/2025
When the aircraft towbarless towing vehicle (TLTV) drives on road surfaces that are wet, icy, oily, or covered with debris, as well as under conditions such as overloaded towing, uneven distribution of aircraft weight, sudden acceleration and sharp turns, brake system failures, or severe tire wear, it may slip due to a mismatch between traction force and ground adhesion. As a key piece of ground support equipment at airports, the anti-slip performance of TLTV is crucial for ensuring safe and efficient ground movement of aircraft. With continuous advancements in control technology, extensive research has been conducted on anti-slip control strategies for TLTV. This paper reviews relevant literature in the field of anti-slip control for TLTV in recent years, focusing on the current status of anti-slip control technology development, control strategies, and the application of co-simulation technology in anti-slip control. Based on co-simulation using Matlab and Adams software, this paper employs a fuzzy PI control algorithm to optimize the traditional PI control algorithm for dual closed-loop control and analysis of the rotational speed and current of the Permanent Magnet Synchronous Motor (PMSM) in the TLTV. The results indicate that the control algorithm is a primary factor affecting stability. A comparative analysis of stability data before and after optimization reveals that the optimized control system exhibits stronger anti-interference capability, thereby enhancing the stability of the TLTV system. The control strategy demonstrates significant effects in improving the anti-slip performance of TLTV. The use of Matlab and Adams co-simulation technology provides effective means for analyzing and verifying anti-slip control strategies. The future development trend of anti-slip control technology for TLTV will emphasize intelligence, precision, and integration to adapt to diverse airport operating environments and improve the safety and efficiency of traction operations.
Yao, Yanan, Xu, Yitong, Zhu, Hengjia
Decelerations for Vehicles with Anti-Lock Brake Systems (ABS) during Wet-to-Dry Transitions on Asphalt and Concrete Road Surfaces2025-01-87034/1/2025
The braking performance of newer anti-lock braking system (ABS) equipped vehicles on roads with varying wetness levels is not well studied. Two late-model ABS-equipped vehicles were used to perform ABS-engaged braking tests on dry and wet asphalt and concrete surfaces from which vehicle speed and deceleration as a function of time were calculated. Tests were initially conducted on a dry surface before a water truck distributed water onto the road to create a wet road condition. A continuous series of tests were then performed until the road dried and the cycle was repeated multiple times. Across all tests of both vehicles on both road surfaces, deceleration levels generally decreased when the road was wet and returned to dry levels only when less than 25% of the road surface remained wet. Also, wet deceleration levels were high compared to the historical values used for wet roads. These findings provide a useful and readily identifiable boundary between what can be considered a dry and wet road from the perspective of choosing a maximum deceleration level when reconstructing collisions involving ABS-equipped vehicles during ABS-enabled braking.
Miller, Ian, King, David, Siegmund, Gunter
NASA’s Inspection Technology for Spacecraft Tests Quality of Seacraft HullsTBMG-5222312/5/2024
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.
Komatsu employs ‘slick’ battery swapping for underground LHD machine24TOFHP12_1012/1/2024
Komatsu introduced its first battery-electric load-haul-dump (LHD) machine, the WX04B, at the MINExpo tradeshow in September. The WX04B is designed specifically for narrow vein mines in underground hard rock mining operations. Komatsu is pairing the electric LHD with its new OEM-agnostic 150-kW battery charger that was also revealed in Las Vegas. The 4-tonne WX04B LHD features what Komatsu claims is best-in-class energy density, offering up to four hours of runtime on a single charge. The Li-ion NMC (nickel-manganese-cobalt) battery from Proterra has a capacity of 165 kWh and nominal voltage of 660 V. Fewer charge cycles are needed compared to competitors, the company claims, which helps to maximize operational efficiency and minimize downtime. Proterra and Komatsu began their collaboration on the LHD's H Series battery system in 2021, long before Komatsu's acquisition of American Battery Solutions (ABS) in December 2023.
Gehm, Ryan
Antilock Brake Systems Energy Consumption Test Procedure for Air-Brake-Equipped Truck Tractors, Buses, Trailers, and DolliesJ2255_202411 (Current)11/22/2024
This SAE Recommended Practice provides instructions and test procedures for measuring air consumption of air braked vehicles equipped with Antilock Brake Systems (ABS) used on highways.
Truck and Bus Brake Systems Committee
Analysis of road safety implementation strategies to support the easiest introduction of autonomous braking products for complex vehicle combinations2024-36-03198/9/2024
In contrast to passenger cars, whose regulation allowed only a simple trailer combination, the autonomous technologies implementation of Electronic Stability Control (ESC) and Advanced Emergency Braking System (AEBS) for commercial vehicles demands more application and calibration efforts. At this case, the focus is on dynamic control of towing vehicles when applying the service brakes of trailer, in special when complex combination as bi-train and road-train, allowed in North and South America. However, the major risk is present occurrence when an ESC or AEBS equipped towing vehicles is connected to a double or triple trailer combination with a conventional braking system, it means: a system that is not equipped with Anti-lock Braking System (ABS). For instance, if during autonomous control, trailers wheels lock, a jackknifing phenomenon can easily occur. Therefore, in case longer and heavier vehicles (LHV) or megatrucks as called in Europe, the strategy for safety assistance systems application should consider trailer configuration maturity level of public reading fleet. In this context, the article aims to propose strategies of implementation and product development that can support the easiest introduction of road safety technologies based on autonomous braking products, in special when it is applied in markets where towed vehicles fleet are greater participation of vehicles equipped with conventional braking system, as occur in Brazil. In order to deliver this, a bibliographic research was carried out looking the available regulation and polities from markets where ESC and AEBS were already implemented, like EU and US. In addition, it was studied an Argentine government program that introduce at same time: road safety technologies, technological fleet renewal policies, periodic vehicle inspection, however offsetting the increased costs with logistical benefits for transport business.
Guarenghi, Vinicius Mendes, Pizzi, Rafael Fortuna, Depetris, Alessandro, Pinto, Gustavo Laranjeira Nunes, Collobialli, Germano
Design and Testing of Antiskid Brake Control Systems for Total Aircraft CompatibilityARP1070E (Current)5/14/2024
This document outlines the development process and makes recommendations for total antiskid/aircraft systems compatibility. These recommendations encompass all aircraft systems that may affect antiskid brake control and performance. It focuses on recommended practices specific to antiskid and its integration with the aircraft, as opposed to more generic practices recommended for all aircraft systems and components. It defers to the documents listed in Section 2 for generic aerospace best practices and requirements. The documents listed below are the major drivers in antiskid/aircraft integration: 1 ARP4754 2 ARP4761 3 RTCA DO-178 4 RTCA DO-254 5 RTCA DO-160 6 ARP490 7 ARP1383 8 ARP1598 In addition, it covers design and operational goals, general theory, and functions, which should be considered by the aircraft brake system engineer to attain the most effective skid control performance, as well as methods of determining and evaluating antiskid system performance. For definitions of terms used herein, see Section 7.
A-5A Wheels, Brakes and Skid Controls Committee
Enhancing Regenerative Energy Capture in Electric Vehicles: Braking Performance through Integral Sliding Mode Control10-08-02-00124/18/2024
This article focuses on the development of an active braking control system tailored for electric vehicles. The essence of this system lies in its ability to regulate the slip coefficient to optimize traction during braking, thereby maximizing energy recuperation. In the context of the simulation on enhancing regenerative energy capture in electric vehicles, the use of integral sliding mode control (ISMC) as an alternative for regulating braking performance can be understood through a comparison of two key output variables in braking control systems: wheel deceleration and wheel slip. Traditionally, wheel deceleration has been a controlled variable in braking systems, and it is still utilized in some anti-lock braking systems (ABS). It can be easily measured using a basic wheel encoder. However, the dynamic performance of wheel deceleration control may suffer when there are rapid changes in the road surface. On the contrary, regulating wheel slip offers high robustness from a dynamic perspective. Despite its robustness, accurately measuring wheel slip poses a challenge as it necessitates estimating the vehicle speed. Nonetheless, despite this challenge, controlling wheel slip remains the most suitable option for designing braking controllers that can adapt to variations in road surface conditions. Therefore, integrating ISMC into the braking system as an alternative enables more effective regulation of wheel slip, enhancing the overall performance and resilience of the braking system, which is particularly crucial in electric vehicles where optimizing regenerative braking is a significant concern. The article explores the theoretical dynamics of electric vehicle braking maneuvers and introduces the concept of an ISMC for managing the slip coefficient. Utilizing a robust control law in conjunction with this controller guarantees the exponential convergence of slip error. Afterward, we explore the visualization and simulation of the braking process performed by the ISMC, as well as the storage of the recovered energy in a supercapacitor system using MATLAB/Simulink.
Direm, Chaima, Hartani, Kada
An advanced tire modeling methodology considering road roughness for chassis control system development2024-01-23174/9/2024
As the automotive industry accelerates its virtual engineering capabilities, there is a growing requirement for increased accuracy across a broad range of vehicle simulations. Regarding control system development, utilizing vehicle simulations to conduct ‘pre-tuning’ activities can significantly reduce time and costs. However, achieving an accurate prediction of, e.g., stopping distance, requires accurate tire modeling. The Magic Formula tire model is often used to effectively model the tire response within vehicle dynamics simulations. However, such models often: i) represent the tire driving on sandpaper; and ii) do not accurately capture the transient response over a wide slip range. In this paper, a novel methodology is developed using the MF-Tyre/MF-Swift tire model to enhance the accuracy of ABS braking simulations. The methodology – developed between Hyundai Motor Company and Siemens Digital Industries Software – is validated on a full-vehicle level by comparing ABS braking simulations of ‘sandpaper’, ‘asphalt’, and ‘translated asphalt’ tire models against full-vehicle measurements, where friction modeling provided a way to translate sandpaper tire models to represent tires on asphalt. Results show a much-improved correlation of the asphalt-based simulations with vehicle measurements compared with flat-trac-based simulations. Thus, the methodology provides a suitable tire model for ABS braking simulations in the early stages of vehicle development without requiring physical vehicle tests.
Kim, Changsu, O'Neill, Alexander, Lugaro, Carlo
An Improved AEB Control System Based on Risk Factors with Consideration of Vehicle Stability2024-01-23314/9/2024
Intelligent vehicle-to-everything connectivity is an important development trend in the automotive industry. Among various active safety systems, Autonomous Emergency Braking (AEB) has garnered widespread attention due to its outstanding performance in reducing traffic accidents. AEB effectively avoids or mitigates vehicle collisions through automatic braking, making it a crucial technology in autonomous driving. However, the majority of current AEB safety models exhibit limitations in braking modes and fail to fully consider the overall vehicle stability during braking. To address these issues, this paper proposes an improved AEB control system based on a risk factor (AERF). The upper-level controller introduces the risk factor (RF) and proposes a multi-stage warning/braking control strategy based on preceding vehicle dynamic characteristics, while also calculating the desired acceleration. Furthermore, a lower-level PID-based controller is designed to track the desired acceleration and compute the corresponding brake master cylinder pressure and throttle opening using an established inverse longitudinal dynamics model. Furthermore, to address vehicle stability during braking, an Anti-lock Braking System (ABS) controller is integrated with the proposed AERF. The effectiveness of the AERF is validated through software co-simulation and hardware-in-the-loop testing (HIL). The results demonstrate that the AERF can maintain a safe braking distance within 2 meters under Euro NCAP standard conditions, with excellent tracking performance of the actual braking deceleration and an error rate below 5%, ensuring a high level of system safety.
Guo, Shaozhong, Guo, Jun, Zhang, Yunqing, Wu, Jinglai
Experimental Analysis of the Influence of Damper Degradation by Loss of Oil on the Straight Braking Performance of Passenger Cars with ABS2024-01-50363/19/2024
The aim of this study is to determine if the degradation of one or more dampers of a passenger car with ABS leads to a statistically significant reduction of vehicle safety. Therefore, a compact and a mid-size car are tested on a flat test track and on an uneven test track by straight braking maneuvers at different levels of damper degradation. Both test tracks are scanned using a 3D laser scanner. For every level of damper degradation (on each test track) a new set of tires is used, a preconditioning routine is applied and 30 successful measurements are conducted to allow using statistical methods to evaluate the results. The results show that any level of damper degradation with each type of car and test track leads to a significant increase in braking distance and, therefore, to a significant reduction of vehicle safety. The braking distance extension varies heavily with the level of damper degradation and the road properties. The observed extensions range from a little more than 2% to more than 30% of the braking distance of the intact state. However, the vehicle’s behavior does not deteriorate linearly as the oil volume goes down. The longest braking distance (when one damper is degraded) can already be at higher oil volumes, as this study suggests. As one possible cause, the reduced functionality of the ABS at asymmetrical levels of degradation is examined. This is the first study that applies statistical methods to straight braking distance measurements investigating damper degradation and offers the comparison of 11 different configurations with 30 measurements each. Additionally, the quality of the results is improved by the analysis of the properties of the two used test tracks and the transparent preconditioning routines.
Zwosta, Tobias, Kubenz, Jan, Prokop, Günther
Numerical Modelling and Simulation of Anti-lock Braking System for Two-wheeler Electric bike using Scilab Xcos2023-01-51392/23/2024
Disc brakes are the most popular type of brakes used in the two-wheeler segment and are easily available in the market. The improper brakes result in serious problems in vehicles. The main idea of this paper is to design a braking system for a two-wheeler application. The paper discusses the design, analysis, and simulation of disc brakes. The disc is first selected using the standard brake disc calculation. To verify the selection of disk, torque at wheel and torque at the disc are compared. Thermomechanical (Transient) analysis is done on ANSYS 2021 to check for the effect of braking force applied by the disc on the rotor disc. The mathematical model of the ABS model is done on Scilab Xcos. The main aim of studying the system using a mathematical model is to verify if the selected disc brakes are safe enough to be installed on a two-wheeler. The mathematical model also has stopping distance and the stopping time as the output which validates the selection of the disc. Hence best-suited brakes are selected based on the performance and the analysis.
Muthiya, Solomon Jenoris, Sudeep, V., Rohit, B.R., Aakash, K.P., Venkatesh, Gowda B.S., Naveena, B.E., Nandakumar, M.B., Mahesh, B.R.
Regulatory Trends for Enhancement of Road Safety2024-26-01651/16/2024
India is one of the largest markets for the automobile sector and considering the trends of road fatalities and injuries related to road accidents, it is pertinent to continuously review the safety regulations and introduce standards which promise enhanced safety. With this objective, various Advanced Driver Assistance Systems (ADAS) regulations are proposed to be introduced in the Indian market. ADAS such as, Anti-lock Braking Systems, Advanced Emergency Braking systems, Lane Departure Warning Systems, Auto Lane Correction Systems, Driver Drowsiness Monitoring 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 trends and the upcoming developments in the regulation domain with respect to safety.
Nayak, Pratik, Rawal, Vishal, Patil, Kamalesh, Tandon, Vikram, Badusha, Akbar
Calibration of an Inertial Measurement Unit and Its Impact on Antilock Braking System Performance2024-26-00141/16/2024
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 computationally effective transformation that requires only two parameters for compensating the IMU sensor mis-orientation and extracting vehicle acceleration from the IMU signal. This transformation also provides physical intuition on the sensor mis-orientation for gauging the vehicle’s dynamic characteristics. Subsequently, a Kalman filter is utilized to estimate the unresolved offset in longitudinal acceleration. The IMU calibration combined with an ABS algorithm was evaluated in a Hardware-in-Loop experimental setup using IPG TruckMaker®. Improvements in longitudinal acceleration estimates by 94-98% were achieved with the calibration algorithm, when compared to the unprocessed IMU data. Moreover, the processed longitudinal acceleration estimates significantly enhanced wheel slip estimation performance by over 60% for a majority of the test cases, avoiding critical problems of wheel lock, and zero brake torque before the vehicle reaches its crawling speed. The outcomes of this study are expected to contribute as a critical block in the development of an indigenous ABS solution for HCRVs.
Dixit, Chitrartha, Gaurkar, Pavel, Ramakrishnan, Rajesh, Shankar Ram, C S, Vivekanandan, Gunasekaran, Sivaram, Sriram
Truck Tractor Power Outlet for Trailer ABSJ2247_202401 (Current)1/10/2024
This SAE Recommended Practice identifies the minimum truck tractor electrical power output of the stop lamp and ABS (antilock brake system) circuits measured at the primary SAE J560 tractor trailer interface connector(s).
Truck and Bus Electrical Systems Committee
Automotive Stability Enhancement SystemsJ2564_202312 (Current)12/7/2023
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
IMU Based Velocity Estimation Impact on Stopping Distance for Heavy-Duty Class 8 Truck Air Brake Systems with ABS2023-01-187311/5/2023
An accurate estimate of vehicle speed is essential for optimal anti-lock braking system (ABS) calculations. Currently, most vehicles including heavy-duty class 8 trucks mainly rely on wheel speed sensors (WSS) to estimate velocity. However, as soon as braking is applied, WSS become inaccurate for determining the velocity due to the longitudinal slip developed in the tires. Using the inertial measurement unit (IMU) to estimate vehicle speed allows for its use in conjunction with the WSS to accurately calculate the slip ratio at each tire. These slip ratio values can then be used as the main control variable in the ABS algorithm to utilize the grip available more fully at each tire, to improve stopping distance and controllability. A steady state braking analysis model is developed and validated against Federal Motor Vehicle Safety Standards (FMVSS) 121 60-0 mph stopping distance data for a loaded class 8 tractor semi-trailer combination. Once the model is validated to show good correlation to measured deceleration data, it is used to estimate the theoretical peak steady state deceleration with the ideal slip ratio at each tire. Then a semi-empirical approach is used to consider current air brake system and ABS algorithm capabilities in the analysis. Lastly, the initial transient phase of 60-0 mph stop is accounted for to get a realistic stopping distance improvement estimate for a loaded heavy-duty truck.
Erdos, Tamas
ABS Exciter Ring Location StandardizationJ1730_202310 (Current)10/2/2023
This SAE Recommended Practice establishes the antilock brake system (ABS) sensor interface and envelope dimensions for standardizing the location of the ABS rings mounted on or integral to the inboard end of spoke wheels, hubs, rotors, and hub-rotor assemblies on the following axle designations as defined in SAE J1842. a FF b FL c FC d FH e L f R g U h W j N k P
Truck and Bus Wheel Committee
A Mid-fidelity Model in the Loop Feasibility Study for Implementation of Regenerative Antilock Braking System in Electric Vehicles10-07-03-00227/29/2023
The tailpipe zero-emission legislation has pushed the automotive industry toward more electrification. Regenerative braking is the capability of electric machines to provide brake torque. So far, the regenerative braking feature is primarily considered due to its effect on energy efficiency. However, using individual e-machines for each wheel makes it possible to apply the antilock braking function due to the fast torque-tracking characteristics of permanent magnet synchronous motors (PMSM). Due to its considerable cost reduction, in this article, a feasibility study is carried out to investigate if the ABS function can be done purely through regenerative braking using a mid-fidelity model-based approach. An uni-tire model of the vehicle with a surface-mount PMSM (SPMSM) model is used to verify the idea. The proposed ABS control system has a hierarchical structure containing a high-level longitudinal slip controller and a low-level SPMSM torque controller. Given the uncertainties of the tire–road dynamics, a sliding mode control method is designed and employed as a high-level slip controller. Also, a PID vector control method is used to keep the SPMSM braking torque at the optimal value requested by the high-level controller. Moreover, in order to estimate the tire longitudinal slip and vehicle velocity, an extended Kalman filter (EKF) is developed that estimates both parameters at the same time. The results show that the proposed hierarchical control and estimators can keep the tire longitudinal slip at the optimal value and prevent the wheel from locking in a variety of road conditions.
Ghanami, Nastaran, Nikzadfar, Kamyar, Mohammadi Daniali, Hamid Reza
A Multiple-Input Multiple-Output Radar-Based Rider Assistance System for Personal Light Electric Vehicles2023-01-50407/6/2023
The use of personal light electric vehicles (PLEVs), such as electric scooters, has rapidly increased in recent years. However, their widespread use has raised concerns about rider safety due to their vulnerability in shared traffic spaces. To address this issue, this paper presents a radar-based rider assistance system aimed at enhancing the safety of PLEV riders. The system consists of an adaptive feedback system and a single-channel anti-lock braking system (ABS). The adaptive feedback system uses multiple-input multiple-output (MIMO) radar sensors to detect nearby objects and provide real-time warnings to the rider through haptic, visual, and acoustic signals. The system takes into account traffic density and uses online data to warn about obscured objects, thereby improving the rider’s situational awareness. Results from testing the feedback system show that it effectively detects potential collisions and provides warning signals, reducing the risk of accidents. The ABS is designed to prevent dangerous braking scenarios in single-track vehicles, such as rear-wheel lift-off and front-wheel locking. A virtual model was created to simulate critical riding situations and determine suitable control parameters. Testing of the MiniMAB ABS in real road tests using these parameters showed that it effectively prevented rear-wheel lift-off on high-grip roads and front-wheel locking on low-friction surfaces during emergency braking, improving riding stability and steerability. In conclusion, the results of this study indicate that the use of the proposed rider assistance system has the potential to greatly contribute to the safe and conflict-free shared use of traffic spaces. The system provides real-time warnings to the rider, thereby reducing the risk of accidents. The implementation of the ABS improves riding stability and steerability, providing a safer and more pleasant riding experience. The system offers a new and improved solution to the growing concerns surrounding the safety of PLEV riders.
Pyschny, Jan, Berger, Felix, Rothen, Samuel, Denker, Joachim, Frantzen, Michael, Roder, Felix, Kneiphof, Simon
Model-Free Intelligent Control for Antilock Braking Systems on Rough Roads10-07-03-00175/26/2023
Advances made in advanced driver assistance systems such as antilock braking systems (ABS) have significantly improved the safety of road vehicles. ABS enhances the braking and steerability of a vehicle under severe braking conditions. However, ABS performance degrades on rough roads. This is largely due to noisy measurements, the type of ABS control algorithm used, and the excitation of complex dynamics such as higher-order tire mode shapes that are neglected in the control strategy. This study proposes a model-free intelligent control technique with no modelling constraints that can overcome these unmodelled dynamics and parametric uncertainties. The double deep Q-learning network (DDQN) algorithm with the temporal convolutional network is presented as the intelligent control algorithm. The model is initially trained with a simplified single-wheel model. The initial training data are transferred to and then enhanced using a validated full-vehicle model including a physics-based tire model, and a three-dimensional (3D) rough road profile with added stochasticity. The performance of the newly developed ABS controller is compared to a baseline algorithm tuned for rough road use. Simulation results show a generalizable and robust control algorithm that can prevent wheel lockup over rough roads without significantly deteriorating the vehicle stopping distance on smooth roads.
Abreu, Ricardo, Botha, Theunis R., Hamersma, Herman A.
Anti-Lock Brake System (ABS) Road Test Evaluation Procedure for Trucks, Truck-Tractors, and BusesJ2536_202304 (Current)4/12/2023
Test procedure for anti-lock brake system (ABS/anti-lock) performance for trucks, truck-tractors, and buses over 4536 kg (10000 pounds).
Truck and Bus Brake Systems Committee
Inertia Calculation for Single-Ended Inertia-Dynamometer TestingJ2789_202304 (Current)4/12/2023
This procedure provides methods to determine the appropriate inertia values for all passenger cars and light trucks up to 4540 kg of GVWR. For the same vehicle application and axle (front or rear), different tests sections or brake applications may use different inertia values to reflect the duty-cycle and loading conditions indicated on the specific test.
Brake Dynamometer Standards Committee
Electronically Controlled Brake System with Two-Channel Pressure Control for Electric Vehicles2023-01-06634/11/2023
In this study, we introduce an electronically controlled brake system (ECB) that can be applied to electric vehicles (EVs) and internal combustion engine vehicles (ICEVs). The main features of the ECB include maximizing the regenerative energy while maintaining vehicle stability and ensuring redundancy in automatic braking. The brake system consists of upper and lower units. The newly developed upper unit has a brake-by-wire configuration and can control the front and rear wheel pressures separately. Hereinafter, controlling the front and rear wheel pressures separately is referred to as two-channel pressure control. The regenerated energy can be maximized while appropriately maintaining the distribution of the front and rear braking forces based on the two-channel pressure control during regenerative cooperation. The lower unit is a conventional hydraulic unit for executing anti-lock brake control, electronic stability control and so on. Each of the upper and lower units has a pressure source and is connected via a communication bus. Thus, even if one of the pressure sources malfunctions during automatic braking, sufficient brake forces can be ensured by another brake system.
Watanabe, Shunya, Yamamoto, Takayuki, Masuda, Yoshio, Yamakita, Hiroki
Development and Test of ABS/TCS Controller with Dual-Axis Dynamometer HIL Platform2023-01-08244/11/2023
This paper describes a Hardware-In-the-Loop (HIL) platform based on the dual-axis dynamometer for development and validation of ABS/TCS controllers. Antilock Braking System (ABS) and Traction Control System (TCS) are standard equipment for passenger vehicles. The ABS, an anti-skid braking assistance system, promotes safety by preventing the locking of wheels during braking. TCS is a control system that prevents the wheels from slipping by moderating driving power to the one that is losing its grip on the road. The real-time platform is based on a dSPACE vehicle model and the simulation environment, and it consists of an actual drive motor, hydraulic braking system and Chroma dual-axis dynamometer test bench, which provide more realistic and complicated conditions than the one-axis platform. With dual-axis architecture, it could effectively perform simulation results of model on two axes. In addition, this HIL system could evaluate the different control logics and performance of developed controllers on the real drive and brake control unit.
Liu, Shu-Ting, Chang, ChihWei, Huang, Yen-Hsiang, Lin, Ting-He, Chiu, Joseph, Lee, Jian-Lin
Driveline Control Influence when ABS Active2023-01-06624/11/2023
The interaction between driveline control and anti-lock braking system (ABS) control in electric vehicles (EV) was investigated based on multi-body dynamics (MBD) model and control model co-simulation. Two primary driveline control algorithms, active damping control and wheel flare control, were integrated with ABS control in Simulink model and the influence on ABS control was studied. The event for high mu to low mu transition was simulated. When ABS control is active on low mu surface, the vehicle shows large wheel slip and long duration time before wheel speed returns to stable control. This performance could be improved with activating driveline control. Deceleration uniformity metric shows that active damping control has very small effect when ABS control becomes stable after passing through the high mu to low mu transition period. Driveline damping control can help to reduce vibration, but it is difficult to find satisfied tuning for wheel speed performance. Wheel flare control can help to reduce the large wheel slip more effectively than ABS control. With proper tuning in ABS control, it can achieve smooth transition between wheel flare control and ABS control. Variation study on different brake torque level and different mu surface shows the performance is robust.
Xing, Xing, Clark, Mark, Morris, Robert
Decelerations for Vehicles with Anti-lock Brake Systems (ABS) on Dry Asphalt and Concrete Road Surfaces2023-01-06164/11/2023
Anti-lock brake systems (ABS) produce high levels of vehicle deceleration under emergency braking conditions by modulating tire slip. Currently there are limited data available to quantify the mean, variance, and distribution of vehicle deceleration levels for modern ABS-equipped vehicles. We conducted braking tests using twenty (20) late-model vehicles on contiguous dry asphalt and concrete road surfaces. All vehicles were equipped with a 5th wheel sampled at 200 Hz, from which vehicle speed and deceleration as a function of time were calculated. Eighteen (18) tests were conducted for each vehicle and all tests were conducted from a targeted initial speed of 65 km/h (40 mph). Overall, we found that late-model ABS-equipped vehicles can decelerate at average levels that vary from about 0.871g to 1.081g across both surfaces, and that deceleration levels were on average about 0.042g higher on asphalt than on concrete. We also found that the passenger cars decelerated about 0.087g higher than the vans and SUVs. Data from these tests provide a technical foundation for estimating the mean, variance, and distribution of ABS braking levels.
Miller, Ian, King, David, Wilkinson, Craig, Siegmund, Gunter P.
A Comparison Study on Control Strategies for Optimization of an Anti-Lock Brake System Algorithm Based on Tire Force Measurement in Pure and Combined Slip Conditions of an Automobile2023-01-06944/11/2023
The Anti-Lock Braking System (ABS) is a safety critical feature primarily used to control slipping of wheels, to maximize available traction and minimize stopping distance. Regulatory authorities of many countries have mandated implementation of an ABS as a compulsory safety feature to be present in all road legal automobiles. Hence, apart from avoiding wheel lock-up, an ABS must also ensure that the vehicle maintains its handling stability and steerability while braking. Thus, it is important that the ABS controller modulate and apply adequate amount of brake cylinder pressure. This paper suggests the use of a Tire Force based algorithm to analyze vehicle behavior and accordingly a control law is employed to modulate the wheel brake pressure. A comparison study has been performed among control methods such as Step Gain Reduced Order Model (SGROM) developed using Machine Learning techniques and Linear Quadratic Regulator (LQR) to determine an optimal control law for brake pressure modulation under pure and combined slip condition. The SGROM control technique implements a wheel cylinder pressure gain that is a function of vehicle state variables such as input brake pressure, normalized tire force and vehicle speed. The optimum output pressure gain is estimated by using a machine learning technique that is further elaborated in the paper. The LQR control technique regulates wheel cylinder pressure gains by minimizing cost function based on desired braking characteristics. The control algorithms are evaluated based on standard brake performance tests such as stopping distance, split mu, and brake in turn. Accordingly, an optimal control strategy is selected based on evaluation criteria defined in the standards.
Shaikh, Parvez Shagir, Mehta, Harshal Piyush, Mallikarjunaiah, Umesh, Kamble, Vijay, Maurya, Mithilesh
Optimized PID Controller Using Genetic Algorithm for Anti-lock Brake System2023-01-06964/11/2023
The anti-lock brake system (ABS) is a vital system in modern vehicles that prevents automotive wheels from locking during an emergency brake. This paper aims to introduce an efficient, optimized proportional integral derivative (PID) controller tuned using a genetic algorithm (GA) to enhance the performance of ABS. The PID control method is a very famous control algorithm employed in numerous engineering applications. The GA is used to solve the nonlinear optimization problem and search for the optimum PID controller gains by identifying the solution to the problem. A mathematical model of ABS is derived and simulated using Matlab and Simulink software. The proposed optimized PID-controlled ABS is compared to the conventional ABS controlled using a Bang-Bang controller. System performance criteria are evaluated and assessed under different road adhesion coefficient values to judge the success of the proposed PID controller tuned using GA. The simulated results indicate that the proposed PID controller can offer a significant improvement of ABS performance under any value of road adhesion coefficient.
Mohammed, Omnia, Metered, Hassan, Abdelaziz, Taha
Recommended Practice for Measuring the Exhaust Emissions and Fuel Economy of Hybrid-Electric Vehicles, Including Plug-in Hybrid VehiclesJ1711_202302 (Current)2/14/2023
This SAE Recommended Practice establishes uniform chassis dynamometer test procedures for hybrid-electric vehicles (HEVs) and plug-in hybrid-electric vehicles (PHEVs) designed for public roads. This recommended practice provides instructions for measuring and calculating the exhaust emissions and fuel economy of such vehicles over the following standard test cycles: the Urban Dynamometer Driving Schedule (UDDS), the Highway Fuel Economy Driving Schedule (HFEDS), the US06 Driving Schedule (US06), the SC03 Driving Schedule (SC03), and the cold-start Federal Test Procedure (cold FTP), which is based on the UDDS. However, the procedures are structured so that other driving schedules may be substituted, provided that the corresponding preparatory procedures, test lengths, and weighting factors are modified accordingly. This document does not specify which emissions constituents to measure (e.g., HC, CO, NOx, CO2); instead, that decision will depend on the objectives of the tester. The emissions calculations for PHEV operation are provided as inventory results, weighted in the same manner as fuel and electrical energy consumption. Decisions for on-board versus off-board emissions, relative benefits of emissions-free driving, and how best to weight a cold-start cycle in charge-depleting (CD) mode must first be made before a certification methodology can be determined. Thus, calculations or test methodology intended to certify a PHEV for compliance of emissions standards is beyond the scope of this document. For purposes of this test procedure, an HEV is defined as a road vehicle that can draw propulsion energy from both of the following sources of stored energy: (1) a consumable fuel, and (2) a rechargeable energy storage system (RESS) that is recharged by the on-board hybrid propulsion system, an external electric energy source, or both. Consumable fuels covered by this document are limited to petroleum-based liquid fuels (e.g., gasoline and diesel fuel), alcohol-based liquid fuels (e.g., methanol and ethanol), and hydrocarbon-based gaseous fuels (e.g., compressed natural gas). The RESS is assumed to be an electrochemical battery pack because testing HEVs with capacitors or electromechanical flywheels requires a different approach to tracking energy in and out of the energy storage system. Procedures are included to test CD operating modes of PHEVs, which are designed to be routinely charged off-board, and calculations are provided that combine the CD and CS behavior according to in-use driving statistics. This document does not include test procedures for recharge-dependent (RD) operating modes or vehicles. See Section 3 for the definition of recharge-dependent. This document does not address the methods or equations necessary for calculating the adjusted U.S. Environmental Protection Agency (EPA) miles per gallon (mpg) labels (sometimes referred to as “EPA Five-Cycle” calculations).
Light Duty Vehicle Performance and Economy Measure Committee
On-Board System Requirements for V2V Safety Communications by Non-Light-Duty Vehicles and MotorcyclesJ2945/1B_202212 (Historical)12/21/2022
This SAE Standard specifies the system requirements for vehicle-to-vehicle (V2V) safety system for FHWA vehicle classes 1 (motorcycles and 4 through 13 (non-light-duty), including functional requirements and performance requirements. The system can transmit and receive the SAE J2735-defined BSM over a wireless communications interface; the communications interface itself is outside the scope of this document. This document provides the specifications necessary to build interoperable systems that support V2V safety applications for non-lightweight vehicles, as well as motorcycles which rely on the exchange of BSMs. The document covers vehicle classes not addressed in SAE J2945/1 and SAE J3161/1.
V2X Core Technical Committee
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