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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.

Vehicle yaw stability control (YSC) can actively adjust the working state of the chassis actuator to generate a certain additional yaw moment for the vehicle, which effectively helps the vehicle maintain good driving quality under strong transient conditions such as high-speed turning and continuous lane change. However, the traditional YSC pursues too much driving stability after activation, ignoring the difference of multi-objective requirements of yaw maneuverability, actuator energy consumption and other requirements in different vehicle stability states, resulting in the decline of vehicle driving quality. Therefore, a vehicle yaw stability model predictive control strategy for dynamic and multi-objective requirements is proposed in this paper. Firstly, the unstable characteristics of vehicle motion are analyzed, and the nonlinear two-degree-of-freedom vehicle dynamics models are established respectively.

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.

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.

This paper presents a torque distribution strategy for four-wheel independent drive electric vehicles (4WIDEVs) to achieve both handling stability and energy efficiency. The strategy is based on the dynamic adjustment of two optimization objectives. Firstly, a 2DOF vehicle model is employed to define the stability control objective for Direct Yaw moment Control (DYC). The upper-layer controller, designed using Linear Quadratic Regulator (LQR), is responsible for tracking the target yaw rate and target sideslip angle. Secondly, the lower-layer torque distribution strategy is established by optimizing the tire load rate and motor energy consumption for dynamic adjustment. To regulate the weights of the optimization targets, stability and energy efficiency allocation coefficient is introduced. Simulation results of double lane change and split μ road conditions are used to demonstrate the effectiveness of the proposed DYC controller.

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 pursuit of maintaining a zero-sideslip angle has long driven the development of four-wheel-steering (4WS) technology, enhancing vehicle directional performance, as supported by extensive studies. However, strict adherence to this principle often leads to excessive understeer characteristics before tire saturation limits are reached, resulting in counter-intuitive and uncomfortable steering maneuvers during turns with variable speeds. This research delves into the phenomenon encountered when a 4WS-equipped vehicle enters a curved path while simultaneously decelerating, necessitating a reduction in steering input to adapt to the increasing road curvature. To address this challenge, this paper presents a novel method for dynamically regulating the steady-state yaw rate of 4WS vehicles. This regulation aims to decrease the vehicle's sideslip angle and provide controlled understeer within predetermined limits.

The tire cornering stiffness plays a vital role in the functionality of vehicle dynamics control systems, particularly when it comes to stability and path tracking controllers. This parameter relies on various external variables such as the tire/ambient temperature, tire wear condition, the road surface state, etc. Ensuring a reliable estimation of the cornering stiffness value is crucial for control systems. This ensures that these systems can accurately compute actuator requests in a wide range of driving conditions. In this paper, a novel estimation method is introduced that relies solely on standard vehicle sensor data, including data such as steering wheel angles, longitudinal acceleration, lateral acceleration, yaw rate, and vehicle speed, among others. Initially, the vehicle's handling characteristics are deduced by estimating the understeer gradient.

Multiple actuators equipped in electric vehicles, such as four- wheel steering (4WS) and four-wheel drive (4WD), provide more degrees of freedom for chassis motion control. However, developing independent control strategies for distinct actuator types could result in control conflicts, potentially degrading the vehicle's motion performance. To address this issue, a model predictive control (MPC) based steering-drive cooperated control strategy for enhanced agility and stability of electric vehicles with 4WD and 4WS is proposed in this paper. By designing the control constraints within the MPC framework, the strategy enables single-drive control, single-steering control, and steering-drive cooperative control. In the upper control layer, a linear time-varying MPC (LTV-MPC) is designed to generate optimal additional yaw moment and additional steering angles of front and rear wheels to enhance vehicle agility and lateral stability.

This paper proposes a thorough investigation of steady-state cornering equilibria for cars. Besides equilibria corresponding to normal driving behaviour - herein denoted as stable-normal turn, drifting is attracting increasing attention. When discussing drifting, it is typically assumed that yaw rate and steering angle have opposite signs, i.e. the driver is countersteering, and the rear axle is saturated. Interestingly, another unstable equilibrium is possible, herein referred to as unstable-normal turn. In this work, an attempt to give a comprehensive definition of drift is made. An inverse model is proposed to compute the driver inputs needed to perform a steady-state turn for a given radius and sideslip angle. The mathematical meaning of all equilibria is explored by linearizing the system and analyzing eigenvalues and eigenvectors of the resulting state matrices.

Complex chassis systems operate in various environments such as low-mu surfaces and highly dynamic maneuvers. The existing metrics for lateral motion hazard by Neukum [13] and Amberkar [17] have been developed and correlated to driver behavior against disturbances on straight line driving on a dry surface, but do not cover low-mu surfaces and dynamic driving scenarios which include both linear and nonlinear region of vehicle operation. As a result, an improved methodology for evaluating vehicle yaw dynamics is needed for safety analysis. Vehicle yaw dynamics safety analysis is a methodical evaluation of the overall vehicle controllability with respect to its yaw motion and change of handling characteristic.

The experimental control findings of increasing the handling performance so that the yaw motion of the vehicle is nimble and stable utilizing the upgraded rear wheel steering system equipped with dual-link actuators are shown in this work. In most automobiles, the steering axis is well defined in front suspension. However, unless the vehicle's rear suspension is a sort of double wishbone, the steering axis is not clearly defined in regular multi-link rear suspensions. As a result, most current automobiles have a suspension geometry feature in which the camber and toe angles change at the same time when the assist link is changed to steer the back wheels. To create lateral force from the rear tire while preserving maximum tire grip, the dual-link actuators control for modifying the strokes of suspension links must keep the camber angle constant and adjust only the toe angle.

The emergence of new electric vehicle (EV) corner concepts with in-wheel motors offers numerous opportunities to improve handling, comfort, and stability. This study investigates the potential of controlling the vehicle's corner positioning by changing wheel toe and camber angles. A high-fidelity simulation environment was used to evaluate the proposed solution. The effects of the placement of the corresponding actuators and the actuation point on the force required during cornering were investigated. The results demonstrate that the toe angle, compared to the camber angle, offers more effect for improving the vehicle dynamics. The developed direct yaw rate control with four toe actuators improves stability, has a positive effect on comfort, and contributes to the development of new active corner architectures for electric and automated vehicles.

In order to improve the trajectory tracking accuracy and yaw stability of vehicles under extreme conditions such as high speed and low adhesion, a coordinated control method of trajectory tracking and yaw stability is proposed based on four-wheel-independent-driving vehicles with four-wheel-steering. The hierarchical structure includes the trajectory tracking control layer, the lateral stability control decision layer, and the four-wheel angle and torque distribution layer. Firstly, the upper layer establishes a three-degree-of-freedom vehicle dynamics model as the controller prediction model, the front wheel steering controller is designed to realize the lateral path tracking based on adaptive model predictive control algorithm and the longitudinal speed controller is designed to realize the longitudinal speed tracking based on PID control algorithm.

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.

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).

The Brake Pull phenomena is the directional deviation when a strong deceleration is applied, this happens due to asymmetries in the vehicle with diverse origins: dimensional, stiffness, damping, friction and loading condition. This phenomenon creates the necessity of driver inputs on the steering wheel adjusting the vehicle direction to keep the straight line. Great part of asymmetries in the vehicle is avoidable due to building quality, correct maintenance, and others. However, an unequal loading condition on the transversal direction of the vehicle is very common: the vehicle occupied only by the driver is a usual condition. This circumstance creates a load asymmetry that can induces the brake pull phenomena. This study aims to create and validate a virtual toll capable of representing the brake pull phenomena caused by a loading asymmetry.

As an important way of energy saving and environmental protection, the lateral stability of straddle-type monorail vehicle (STMV) has attracted more and more attention. In order to solve this problem, a semi-active lateral control strategy of STMV dynamic model based on magnetorheological fluid damper is proposed. The inverse model of magnetorheological damper is constructed by neural network. An adaptive neural fuzzy algorithm for STMV dynamic model based on body acceleration and velocity feedback is designed, and its feasibility is verified by Kalman filter method. Through the simulation comparison of lateral acceleration and yaw angular acceleration, the control method has good measurement accuracy and can meet the needs of practical engineering measurement. It provides a method and basis for the stability and effectiveness of STMV swing semi-active control.

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.