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Due to coupling of in-wheel motor and wheel/tire, the electric wheel system of in-wheel motor driven vehicle is different from tire suspension system of internal combustion engine vehicle both in the excitation source and structural dynamics. Therefore emerging dynamic issues of electric wheel arouse attention. Longitudinal vibration problem of electric wheel system in starting condition is studied in this paper. Vector control system of permanent magnet synchronous hub motor considering dead-time effect of the inverter is primarily built. Then coupled longitudinal-torsional vibration model of electric wheel system is established based on rigid ring model and dynamic tire/road interface. Inherent characteristics of this model are further analyzed. The vibration responses of electric wheel system are simulated by combining electromagnetic torque and the vibration model. The results indicate that abrupt changes of driving torque will cause transient vibration of electric wheel system.

Real-time simulation of tracked vehicle dynamics demands very efficient modeling of the vehicle track. Multi-body dynamics models which model the response of each track pitch are complete, but require on the order of 100 degrees of freedom to capture lateral track dynamics and an additional 200 degrees of freedom to capture longitudinal (stretching) track dynamics. The sheer size of such models renders them difficult to use for rapid estimates of track response. This paper summarizes an efficient alternative for modeling vehicle tracks, as illustrated herein by a model for longitudinal track dynamics. The present model is a hybrid discrete/continuous model in which the track is modeled as a continuous uniform elastic rod which is kinematically coupled to discrete models for the sprocket, wheels, and rollers. Solution efficiency derives from transforming the dynamic track model to one employing modal coordinates.

Anti-lock braking systems are one of the most important safety systems for wheeled vehicles. They reduce the braking distance and, most importantly, help the user maintain controllability and steerability of the vehicle. This paper extends and adapts the concept of Anti-lock braking systems to tracked vehicles, specifically to snowmobiles. Snowmobiles are an interesting development platform for two main reasons: 1) track dynamics, despite being analogous to tire dynamics, present important differences that help understanding the features of the control algorithm and 2) snowmobiles are simple and rugged vehicles with a limited set of sensors, making the design of an effective control system challenging. The paper designs a track-deceleration based ABS algorithm and tests it both in straight riding and cornering.

The sugarcane industry holds the second largest share of production value in the Brazilian agricultural sector, with Brazil responsible for more than 20% of the world’s production. Therefore, the increase of efficiency in the production process of sugarcane is an object of interest for producers, with transportation playing an important role in the process, both economically and environmentally. Intending to improve the efficiency in the transportation of sugarcane between cultivation and processing facilities, this work uses simulations to analyze safety aspects of a vehicle combination with 11 axles and 91ton capacity, new to the Brazilian transportation system. Several procedures were performed in a virtual environment to evaluate the vehicle longitudinal and lateral dynamics, including weight distribution, overtaking performance, rollover threshold, rearward amplification, braking and gradeability.

Advanced Driver Assistance Systems (ADAS) is an essential aspect of the automotive technology in this era of technological revolution, where the goal is to make vehicles more convenient, safe, and energy efficient. Taking advantage of more degrees of freedom available within vehicle “energy management” allows more margin to maximize efficiency in the propulsion systems. It is envisioned by this research that future fuel economy regulations will consider the potential benefits of emerging connectivity and automation technologies of vehicle’s fuel consumption. The application focuses on reducing the energy consumption in vehicles by acquiring information about the road grade. Road elevation are obtained by use of Geographic Information System (GIS) maps in order to optimize the controller. The optimization is then reflected on the powertrain of the vehicle. The approach uses a Model Predictive Control (MPC) algorithm that allows the energy management strategy to leverage road grade.

With the advent of autonomous vehicles, the human driver’s attention will slowly be relinquished from the driving task. It will allow drivers to participate in more non-driving related activities, such as engaging with information and entertainment systems. However, the automated driving system would need to notify the driver of upcoming points-of-interest on the road when the driver’s attention is focused on their screen rather than on the road or driving display. In this paper, we investigated whether providing directional alerts for an upcoming point-of-interest (POI) in or around the user’s active screen can augment their ability in relocating their visual attention to the POI on the road when traveling in a vehicle with Conditional Driving Automation. A user study (N = 15) was conducted to compare solutions for alerts that presented themselves in the participants’ central and peripheral field of view.

The commercialization of methanol fuel cell vehicles will offer practical, affordable, long-range electric vehicles while retaining the convenience of a liquid fuel. Given the automotive industry's strong commitment to develop methanol fuel cell vehicles, we must address the need for fueling infrastructure to serve these vehicles. From past experience in building methanol fueling stations, we estimate the cost to add methanol fueling capability to an existing gasoline station is $50,000. Assuming retail stations are required to cover North America, Europe and Japan, it would cost $1.9 billion for 10% of the existing stations and $4.7 billion for 25% of the stations.

High-speed cine photography has been used to study the combustion process in a variety of diesel chambers. These chambers, used in engines of 12–1200 cu in. swept volume per cylinder, differ considerably in the level of air utilization achieved within the cylinder at acceptable exhaust color or temperature. These differences are attributed to the method of fuel/air mixing employed and the influence of fuel injection, air motion, and fuel quality are discussed. It is concluded that while there is an obvious correlation between air utilization and the level of air swirl or turbulence employed, from other points of view high gas velocities are undesirable. Further development will therefore depend largely on the evolution of the fuel injection equipment toward the achievement of good mixing and combustion control with reduced gas velocities.

To secure the reliability of bolted joints, high clamping force (axial tension) is required to prevent fatigue breakage or loosening failure, and so on. In this paper, at first, we observe the behavior of the initial clamping force decrease tendency (loosening phenomenon) obtained by tightening the bolt used in the actual machine (large forklift) during operation. Based on our previous research, there is a strong linear relationship on log-log paper of loosening phenomenon between decrease tendency of clamping force and distance travelled (or passage of time). By utilizing its properties, we show estimation method of residual clamping force such as "How much the clamping force is remaining after the tens of thousands of hours (kilometers)?" Also, a method for estimating loosening lifetime with respect to residual clamping force level is shown. Finally, we examine evaluation criteria such as "Is the residual clamping force sufficient for prevention of loosening failure?"

This paper presents air monitoring data and references which show the following: Los Angeles photochemical and auto-caused air pollution is by far the worst in the U.S. Due to the control programs, Los Angeles air is much cleaner. The improvements are dramatic in the last few years. Downwind stations, such as Riverside, never had such high air pollution levels as Pasadena, and Riverside now is showing decreased levels. Sulfur dioxide and sulfate levels are not likely to reach as high levels in the early 1980's as were reached in the early 1950's before sulfur was limited in fuel oil.

In the discussion on the reduction or complete avoidance of CO2-emissions and other pollutants in the transport sector, hydrogen as a carbon-free fuel, is an alternative to conventional fuels. The use of hydrogen in modern internal combustion engines offers a fast and cost-effective opportunity of decarbonisation of the transport sector. The utilisation of hydrogen as fuel in internal combustion engine systems is more challenging than using conventional fuels. Hydrogen is highly flammable, which affects the requirements of the ignition system and the design of the combustion chamber. In addition, due to the gaseous state of H2 the question, how the fuel should be delivered to the combustion chamber is of high importance by means of engine performance. There are two fundamentally different concepts for hydrogen injection. Hydrogen can be injected by a multi-point injection into intake manifold by external mixture-formation (MPI) or directly into the combustion chamber (DI).

Partially Premixed Combustion (PPC) has demonstrated substantially higher efficiency compared to conventional diesel combustion (CDC) and gasoline engines (SI). By combining experiments and modeling the presented work investigates the underlying reasons for the improved efficiency, and quantifies the loss terms. The results indicate that it is possible to operate a HD-PPC engine with a production two-stage boost system over the European Stationary Cycle while likely meeting Euro VI and US10 emissions with a peak brake efficiency above 48%. A majority of the ESC can be operated with brake efficiency above 44%. The loss analysis reveals that low in-cylinder heat transfer losses are the most important reason for the high efficiencies of PPC. In-cylinder heat losses are basically halved in PPC compared to CDC, as a consequence of substantially reduced combustion temperature gradients, especially close to the combustion chamber walls.

The wireless charging system of electric vehicles will be of high power. Due to environmental problems and the heat emission design of the machines, it is not easy to improve the efficiency of the power transmitting system. While improving the efficiency of the overall system is important, it is especially significant to improve the efficiency of the transmitting and receiving antennas. Improving the antennas is necessary as it accounts for a large part of the overall efficiency and it has strong relation to the transfer characteristics. In this paper, the importance of reducing the antenna loss for high power implementation is discussed. We showed that the antenna losses not only affecting the transfer efficiency but also the maximum power consumed by the load (the available power) by deriving an equation.

The insulated-gate bipolar transistor (IGBT) is the most important part of a power converter. The heat generated during operation will cause the junction temperature of the IGBT to rise above ambient temperature. The junction temperature must stay within its predefined limit to ensure reliable operation. A properly designed cooling system is crucial for the overall operation, and an accurate prediction of power loss is critical in the design of a good thermal system. In this paper, a pulse-width modulation (PWM) full-bridge converter is designed for free-piston engine generators (FPEGs), and a low-cost forced-air cooling system is used for heat dissipation. For the converter to choose the IGBT module or discrete IGBT as the switching device, loss and thermal analyses are carried out. The loss analysis model of the converter is established, which considers the influence of the IGBT parasitic capacitance and gate driver voltage on the switching losses.

During the early phase of vehicle development, one of the key design attributes to consider is the inner comfort for occupants. Internal spaciousness is the pillar that is responsible for user's comfort and make into customer comfort needs in engineer metrics. Therefore, it is one of the key requirements to be considered during the vehicle design. Certain internal vehicle characteristics such as the size of shoulder room and the knee clearance are engineer metrics that influence the perception of comfort for occupants. One specific characteristic influencing satisfaction is the headroom, which is the subject of this paper. The objective of this project is to analyze the relationship between the vehicle headroom with the driver satisfaction under real world driving conditions, based on research, statistical data analysis and dynamic clinics. Other influences, such as the position of the driver in the seat was also studied and captured in this paper.

In vehicle design, the H point is a theoretical relative location measured in relation to specific characteristics, for example, H point to vehicle floor (H30), H point to ground (H5) and others. Based on theoretical H point automakers concept their vehicle and have to make important decisions on vehicle architectural that could result in a bad product for the future customers and during the early phase of vehicle development, one of the key design attributes to consider is in relation to the comfort of the user, so that its design and its components enable a favorable interaction with the occupant. Accessibility is one of the pillars on which this concern can be observed. Certain features such as the size of door opening and the height of the vehicle from the ground, among others, may influence the level of satisfaction of the occupants’ access.

During the early phase of vehicle development, one of the key design attributes to consider are the interior storages for occupants. Internal storage is the pillar that is responsible for user’s comfort and make into customer comfort needs in engineer metrics. Therefore, it is one of the key requirements to be considered during the vehicle design. The vehicle has some interior storages, like storages on door trim, floor console and IP and to define the best solution for the customer, engineering team has certain internal vehicle characteristics such as the volume and size of storage are engineer metrics that influence the perception of comfort for occupants. One specific characteristic influencing satisfaction is the glove box volume, which is the subject of this paper.

During the early phase of vehicle development, one of the key design attributes to consider is the inner comfort for occupants. Internal spaciousness is the pillar that is responsible for user’s comfort and make into customer comfort needs in engineer metrics. Therefore, it is one of the key requirements to be considered during the vehicle design. Certain internal vehicle characteristics such as the size of shoulder room and the knee clearance are engineer metrics that influence the occupants’ perception for comfort. One specific characteristic influencing satisfaction is the headroom, which is the subject of this paper. The objective of this project is to analyze the relationship between the second row’s vehicle headroom with the occupant’s satisfaction under real world driving conditions, based on research, statistical data analysis and dynamic clinics.

India has one of the highest growth rates of individual mobility in the world, as well as one of the largest numbers of road casualties. Modern active safety systems are slowly becoming established in the Indian passenger car market. The intension of this study is to investigate the effectiveness of the car safety feature Electronic Stability Control (ESC) for India. The Indian accidents has to be analysed to identify the reliable root cause. For this purpose, passenger car Loss of Control accidents were investigated in more detail with the aim of estimating the safety potential of ESC for India. A methodology is developed to extrapolate the in-depth accident database of Road Accident Sampling System for India (RASSI) to the entire accident situation in India. Loss of Control accidents are analysed with regard to their root causes, crash consequences and contributing factors.

The loss of preload in bolted joints is the main cause of quality problems, reworks or even joint failures during work. Several measurement methods are presented in the literature, but the difference of precision between each one or even the right criteria to select the most appropriate method for each project is not clearly defined. This study evaluated the differences between two of the main losses of preload measurements methods currently used in the market: clamp load through elongation measurement by ultrasonic method and checking torque method. For this, a load cell was used to measure the clamp load after the tightening torque and joint relaxation. Since the checking torque method is one of the most frequently used method of the torque auditing, it is also presented a torque x angle curve analysis for different torque points that are normally displayed by the measuring equipment.