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Conventional trajectory planning methods encounter various challenges: Inability to better distinguish different types of vehicles, and failure to consider the difference between perceived threats or risks during asymmetric and symmetric interactions for autonomous vehicles. To solve these issues, the insufficiency of the traditional risk-field model is analyzed, and an asymmetric aggressiveness model is investigated in this study, which quantifies the suffered aggressiveness of vehicles. Then, the asymmetric aggressiveness model and the static potential risk field describing the road structure are used as the control objectives of the optimal controller to avoid collisions. Furthermore, a three-degree-of-freedom vehicle dynamics model is constructed, and the optimal feasible trajectory is planned by using the model predictive control algorithm.

Electric technology has gradually changed the form of energy use in transportation. Electric vertical take-off and landing aircraft (eVTOL) will become an important means of transportation in the future, bringing significant changes to urban transportation and providing a more convenient and comfortable travel experience for people. eVTOLs are being extensively researched and developed by the global aviation industry as well as by many innovative technology companies. In this paper, we focus on the system design and testing of the four-axis and eight-propeller eVTOL. The overall parameters of the aircraft are defined, and the energy and power architecture design and analysis are carried out. Carry out the hybrid power supply design of lithium battery and fuel cell, and complete the parameter matching design of power system.

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 active suspension system has strong application potential in electric vehicles (EV) due to its superior controllability. However, the feedback delay of vehicle status information will degrade the control performance of active suspension. This paper investigates the multi-objective control of preview active suspension based on forward-looking information perception. An integrated model including the forward-looking system, vehicle dynamics system and control switching system is established. First, a multi-degree-of-freedom vehicle dynamics model including the input-output system is created, then, an LQR active suspension controller is designed, secondly, a pareto solution set with multiple different target solutions is obtained by calculation, finally, a forward-looking preview mode-switching controller that can select different control strategies according to the road conditions ahead is designed.

The aim of this research is to investigate the effect of cutting temperature on the post-machining performance of “carbon fiber-reinforced polymer” (CFRP), providing insights into how temperature variations during machining influence the material’s mechanical properties and structural integrity. First, cutting temperatures generated during machining were monitored and used to categorize specimens. These specimens were then subjected to control heating at various temperatures, simulating the range of cutting conditions. Subsequently, the heated specimens were left to cool naturally in ambient air. A comprehensive tensile experiment was conducted on these specimens to assess the impact on mechanical behavior. The tensile properties, including elastic modulus and maximum tensile stress, were analyzed and compared across the different temperature.

The study investigates the optimization of design parameters of riveted joints such as diameter of rivet, edge distance, and the amount of nanoclay filler in the modified GLARE laminate single lap riveted joints under pull-through test. Taguchi’s L9 orthogonal array was used to plan the experiments. The failure mechanism of riveted joints was observed to be elongation of rivet hole, followed by stress concentration, crack initiation, propagation in the interface, coalition of multiple cracks leading to delamination in the laminate. The failure of joint finally occurred by rivet pin fracture. The regression equations were developed for both failure load and maximum displacements with prominent level of confidence and the reliability of the equations were confirmed by experiments. The effect of individual and interaction of factors was evaluated using analysis of variance (ANOVA).

Automotive dampers are essential vehicle components regarding vehicle dynamics by keeping the road contact and reducing wheel load fluctuations. So damper degradation could not only significantly influence driving comfort but also the dynamics and therefore driving safety. The aim of this study is to expand knowledge about the behavior of passive automotive twin-tube dampers degraded by loss of oil and pressure. This serves to improve the understanding of inner processes of the damper and modeling the behavior of degraded dampers. To analyze the damper behavior, an intact damper has been modified and validated to allow adjusting the oil and pressure level. Using a dynamic hydraulic damper test rig a preconditioning routine for degraded dampers is developed. With this routine, a wide measurement program at various amplitudes, frequencies, oscillations, and damper configurations is carried out and the obtained results are discussed.

Electrical vertical takeoff and landing (eVTOL) vehicles for urban air mobility (UAM) are garnering increased attention from both the automotive and aerospace industries, with use cases ranging from individual transportation, public service, cargo delivery, and more. Distributed electric propulsion systems are their main technical feature; they determine vehicle size and propulsion efficiency and provide distributed thrust to achieve attitude control. Considering the intended role of eVTOL vehicles, ducted-fan systems are ideal choice for the propulsor, as the duct provides a physical barrier between the rotating blades and the human, especially during the take-off and landing phases. Key Technology Challenges of Electric Ducted Fan Propulsion Systems for eVTOL introduces the main bottlenecks and key enablers of ducted-fan propulsion systems for eVTOL applications.

Due to their various features, aluminum alloy can be used in various applications. These include aerospace, automotive, and electrical and thermal applications. Compared to structural steels, aluminum offers superior corrosion resistance and specific strength. Aluminum alloy known as AA 2014 exhibits various mechanical properties. These include its improved strength and weight ratio. It can also be used in military and aircraft applications. Aluminum alloy is commonly used in various engineering applications, such as the manufacturing of structures and aircraft components. Due to its corrosion resistance, it can be utilized in severe environmental environments. Different methods are used in unconventional ways to generate complicated forms of electrical components. One of these is wire electro-discharge machine (WEDM). This process involves making intricate shapes out of conductive materials.

Due to their inherent properties and superior performance over titanium-based materials, nickel-based superalloys are widely utilized in the manufacturing industry. Monel 400 is among them. This nickel-copper alloy possesses exceptional corrosion resistance and mechanical properties. Monel 400 is primarily utilized in the chemical industry, heat exchangers, and turbine component manufacturing. Due to the properties of Monel 400, it is deemed as hard to machine materials with the aid of conventional methods. For investigating the performance of this process, a three-level analysis was carried out. Pulse on duration and applied current at three levels are the independent parameters used for designing the experiments. In this present article, a single-response analysis technique is used which is known as Taguchi to investigate the impact of the various process parameters on the output variables.

Nickel-based superalloys are frequently adopted in various engineering applications, such as the production of food processing equipment, aerospace parts, and chemical processing equipment. Because of higher strength and thermal conductivity, they are often regarded as difficult-to-machine materials in certain processes. Various methods were evolved for machining the hard materials such as Nickel-based superalloys more effective. One of these is wire electrical discharge machining. In this paper, we will discuss the development of an artificial neural network model and an adaptive neuro-fuzzy inference system that can be used to predict the future performance of Wire Electrical Discharge Machining (WEDM). The paper uses the Taguchi and Analysis of Variance (ANOVA) design techniques to analyze the model’s variable input. It aims to simulate the various characteristics of the process and its predicted values.

Deadweight as payload is an important parameter, which affects the vehicle dynamics and durability of the vehicle. This paper presents a study performed to evaluate the effect of deadweight on dynamic input load, suspension operation, and fatigue life of frame in a two wheeler. Also, an optimization exercise was undertaken to correlate and optimize deadweight with a human payload in terms of equivalent damage to the frame. Strain, wheel acceleration, and suspension displacement data were acquired with pillion and multiple deadweights and compared. Relative damage spectrum (RDS) characterization and best-fit optimization methods were used for deadweight correlation. It was observed that with deadweight addition dynamic loads decreases on the front wheel while increases on the rear. Strain damage wise increasing deadweights have marginal effects on the front zone of the frame while on the middle and rear side, deadweights are detrimental.

Brake squeal is a common phenomenon across all types of vehicles. It becomes prominent in the absence of other noise sources, as in the case of electric vehicles. Earlier simulation attempts date back to late nineties and early 2000s. Identification of unstable modes of the coupled system of brake rotor and pads, and occasionally some caliper components, was the primary goal. Simulating the rotation of the rotor along with squeezing of the pads was attempted in a multi-body dynamics tools with flexible representation of rotor and pads. Though this gave some insights into the dynamics of stopping mechanism, squeal required capturing the nonlinearities of the contact in a more rigorous sense. Also, efforts were made to capture noise from vibrations using boundary- and finite- element methods [1].

The current braking system of a vehicle includes a parking braking system, which consists of a Motor on Caliper (MOC) that generates hydraulic main braking and electric parking braking through a caliper structure. When designing the MOC braking system, it is important to consider an analytical model that can predict the performance of the parking clamping force and the torque generated between the disk and caliper interactions. However, in previous designs, system predictions were often based on simplified structural calculations or incomplete Finite Element Method (FEM) analysis. In this paper, a study was conducted to predict the system performance using Multi-flexible Body Dynamics (MFBD) analysis. Firstly, a kinematic model (MBD) was developed for the Electric Parking Brake (EPB) system currently used in mass-produced vehicles. And the MBD model which based on kinematics was the initial model for this study.

The main purpose of the powertrain mounting system is to reduce excessive motion created by the powertrain system as well as to isolate vibration and noise from being transferred to the main system There are two fundamental requirements which needs to be fulfilled by mounting system, those are static requirement and dynamic requirement. Where the static requirements states that it should support the whole weight of the powertrain system under sever driving conditions and to avoid the metal-to-metal contact between oscillating parts of engine and structure. Dynamic requirement states that it should efficiently isolate the vibration and unbalanced forces, furthermore it should allow the sufficient movement of powertrain so as it will not damage the structure of the chassis. The mounting system also plays a significant role in vehicle ride and handling, as it controls the motion of largest mass of the vehicle i.e., powertrain.

An investigation into emissions differences and their correlations with differing combustion characteristics between F24 and Jet-A was conducted. Raw emissions data was taken from a single stage jet engine by a FTIR gas analyzer. Measurements of H2O, CO2, CO, NOx, and total hydrocarbon emissions (THC) were taken at 60K, 65K, and 70K RPM. At 70K RPM Jet-A and F-24 the emissions were similar at approx.: 4% H2O, 3% CO2, 970 PPM CO, 28 PPM NOx. Jet-A THC emissions were approx.: 1200 PPM THC, F24 THC emissions were lower by over 60%. The significantly lower amount of THC emissions for F24 suggests more complete combustion compared to Jet-A.

To many, a digital twin offers “functionality,” or the ability to virtually rerun events that have happened on the real system and the ability to simulate future performance. However, this requires models based on the physics of the system to be built into the digital twin, links to data from sensors on the real live system, and sophisticated algorithms incorporating artificial intelligence (AI) and machine learning (ML). All of this can be used for integrated vehicle health management (IVHM) decisions, such as determining future failure, root cause analysis, and optimized energy performance. All of these can be used to make decisions to optimize the operation of an aircraft—these may even extend into safety-based decisions.

A new simulation model for motorcycle motion is presented. The model was reproduced the equation of motion which called 10 degrees of freedom (10-DoF) motorcycle model using multi-body dynamics. There are some good reasons to reconstruct equation model by multi-body dynamics, because computer technology helped development of tools which is versatile to expand model. Straight line stability characteristics of motorcycle have been studied by using an equation of motion model for a long time. This model was originally developed by Sharp as a 4-DoF model, later Aoki developed 10-DoF model by adding 6-DoF to take frame stiffness into account. The eigenvalues of the Weave and Wobble mode showed some disagreement between the equation of motion model and the new multi-body dynamics model. The frame lateral bending is represented by the “equilibrium of lateral force” in the 10-DoF equation of motion. It turned out that “lateral force at bending Point” was not expressed in the equation.

In an engine system, the piston pin is subjected to high loading and severe lubrication conditions, and pin seizures still occur during new engine development. A better understanding of the lubricating oil behavior and the dynamics of the piston pin could lead to cost- effective solutions to mitigate these problems. However, research in this area is still limited due to the complexity of the lubrication and the pin dynamics. In this work, a numerical model that considers structure deformation and oil cavitation was developed to investigate the lubrication and dynamics of the piston pin. The model combines multi-body dynamics and elasto-hydrodynamic lubrication. A routine was established for generating and processing compliance matrices and further optimized to reduce computation time and improve the convergence of the equations. A simple built-in wear model was used to modify the pin bore and small end profiles based on the asperity contact pressures.

Advancements in electric vertical takeoff and landing (eVTOL) aircraft have generated significant interest within and beyond the traditional aviation industry. One particularly promising application involves on-demand, rapid-response use cases to broaden first responders, police, and medical transport mission capabilities. With the dynamic and varying public service operations, eVTOL aircraft can offer potentially cost-effective aerial mobility components to the overall solution, including significant lifesaving benefits.