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Electromechanical actuators (EMAs) play a crucial role in aircraft electrification, offering advantages in terms of aircraft-level weight, rigging and reliability compared to hydraulic actuators. To prevent backdriving, skewed roller braking devices called "no-backs" are employed to provide braking torque. These technology components are continuing to be improved with analysis driven design innovations eg. U.S. Pat. No. 8,393,568. The no-back mechanism has the rollers skewed around their own transverse axis that allow for a combination of rolling and sliding against the stator surfaces. This friction provides the necessary braking torque that prevents the backdriving. By controlling the friction radius and analyzing the Hertzian contact stresses, the brake can be sized for the desired duty cycle. No-backs can be configured to provide braking torque for both tensile and compressive backdriving loads.

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

Abrasion of the Electromechanical brake (EMB) brake pad during the braking process leads to an increase in brake gap, which adversely affects braking performance. Therefore, it is imperative to promptly detect brake pad abrasion and adjust the brake gap accordingly. However, the addition of extra gap adjustment or sensor detection devices will bring extra size and cost to the brake system. In this study, we propose an innovative EMB gap active adjustment strategy by employing modeling and analysis of the braking process. This strategy involves identifying the contact and separation points of the braking process based on the differential current signal. Theoretical analysis and simulation results demonstrate that this gap adjustment strategy can effectively regulate the brake gap, mitigate the adverse effects of brake disk abrasion, and notably reduce the response time of the braking force output. Monitoring is critical to accurately control EMB clamping force.

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.

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

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.

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

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

The 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.

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.

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

The braking system is a major part of dealing with Go-karts, where speed and control combine to create an enthusiastic experience. This research article discusses the design and analysis of the braking system of a go-kart vehicle. In this case, constraints are based on rulebooks, and optimisation is performed depending on the requirements. The process flow also carries material selection for components and an analysis to determine their structural and thermal properties. This study also includes a comparison of brake rotors and their specifications to meet the higher performance. The design combines mechanical and hydraulic principle-based components to balance efficiency, cost, and maintenance requirements. In this investigation into the braking system, various design and analysis softwares are used. This study offers a concept for an optimized braking system with enough information to construct the go-kart vehicle's braking system.

An ever-increasing need for effective transportation requires improved safety and maintenance systems. The braking component in an automobile is one of the most important safety features that manufacturers can provide. One of the key factors that influence the performance of the brakes is heat dissipation. For Brake, cooling is the most important factor governing the brake’s performance and longevity. Moreover, poor thermal performance unequivocally leads to blurring of brakes, fast wear, thermal splits and variation of thickness in the disc. To understand the design-oriented factors that affect the brake cooling, a model was developed in Solid Works and imported to CFD modeling to analyze the aerodynamic thermal flow behavior of a ventilated disc brake rotor. Here a complex design is studied and incorporated in the brake rotor to alter the aerothermal flow behavior of the brake rotor. The design is the combination of various existing brake rotors available.

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.

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).

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

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

Despite efforts to reduce disc brake noise occurrence, it remains a significant concern in the automotive industry, particularly in the current era of electric vehicles, where it can be an intermittent issue. There is no standard solution available for every noise frequency, as it depends on various conditions and parameters that need to be experimentally identified and addressed. This paper specifically focuses on addressing low-frequency noise. During dynamic conditions, the contact pressure becomes uneven, leading to uneven pad wear and making the disc brake system susceptible to noise. In noise rigs, the paper selects the most suitable shim and pad geometry based on trials that analyze the interaction between the shim and pad. In conventional practice, shim modification was performed using computer-aided engineering, but obtaining accurate pressure patterns in dynamic conditions with CAE is challenging due to certain assumptions.

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.

Brake wear emissions gained significant relevance with the upcoming Euro7 type approval within the European Union for brake emission measurement on the test bed. While the controlled brake test bed approach provides consistent results, real-driving emission (RDE) measurements are needed to better understand actual emission behavior due to varying vehicle and environmental conditions. The EU has already announced its interest in RDE testing. Here we present the results of an RDE brake wear sampling system with minimal thermal impact, where particles are only sampled from one side of the brake disc, characterized on a laboratory sampling system. The investigations aim to validate symmetric particle release and to confirm that doubling the measured RDE results effectively represents the reference emissions on the test bed.