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Environmental sustainability is morphing Automotive technical development strategies and driving the evolution of vehicles with a speed and a strength hardly foreseeable a decade ago. The entire vehicle architecture is impacted, and energy efficiency becomes one of the most important parameters to reach goals, which are now not only market demands, but also based on regulatory standards with penalty consequences. Therefore, rolling drag from all bearings in multiple rotating parts of the vehicle needs to be reduced; wheel bearings are among the biggest in size regardless of the powertrain architecture (ICE, Hybrid, BEV) and have a significant impact. The design of wheel bearings is a complex balance between features influencing durability, robustness, vehicle dynamics, and, of course, energy efficiency.

Consideration for the damaging effects to aircraft from the failure of wheels and tires should be evaluated. This document discusses the types of problems in-service aircraft have experienced and methodology in place to assist the designers when evaluating threats for new aircraft design. The purpose of this document is to provide a history of in-service problems, provide a historical summary of the design improvements made to wheels and tires during the past 40 years, and to offer methodology which has been used to help designers assess the threat to ensure the functionality of systems and equipment located in and around the landing gear and in wheel wells.

The author proposes a new principle of suspension system. First, a new shock isolation method prevents sudden sharp jolts and enables a body to continue in motion as before, by transforming linear motion into circular motion. This method reduces abrupt deceleration and impact force. Next, we examined the gravity spring action of a pendulum as a new vibration isolation method. Because the pendulum generates longitudinal vibration, it has isolation effect against the longitudinal vibration input. Application of this new principle to aircrafts, automobiles, motorcycles, and even to bicycles and wheelchairs, overcomes the limitations of current technology. This study focused on two as-yet-unresolved safety problems of aircraft undercarriages. One is acceleration impact on the wheels; the other is collision with an obstacle on the runway.

Although autonomous driving technology has become an emerging research focus, safety is still the most crucial concern when autonomous vehicles leave research laboratory and enter public traffic. Direct yaw moment control (DYC), which differentially brakes the wheels to produce a yaw moment, is an important system to ensure the driving stability of vehicle under extreme conditions. Traditional DYC system must need to take into account driver’s intention and vehicle dynamics. However, for autonomous vehicle, no human is involved in driving process, and enforcing traditional DYC system may conflict with the demands of the desired path. Therefore, in this paper, a novel DYC system for autonomous vehicle is proposed to simultaneously suppress lateral path tracking deviation while maintaining autonomous vehicle stability at or close to the driving limits. In the hardware aspect, an integrated-electro-hydraulic brake (IEHB) actuator scheme is adopted.

This paper describes a project to build a practical flying car called Starcar 4. The vehicle actually is more like a flying motorcycle, since it uses three wheels on the road. It has a single seat and weighs a little less than 1200 lbs, so it could be certified as a primary class airplane. The vehicle is practical in the sense that it is about as light and simple as its mission allows. A single engine is used to propel the vehicle on the road and in the air. When not in use, the wings hang on the sides, and the driver plugs them into the fuselage when he wants to fly. Most functions serve in both road and sky modes. The driver can do an aerodynamic wheelie on the ground, and he will shift into fourth gear when he reaches cruise altitude.

In power-split configuration, the input power is split into two parts, one of which is transmitted from the internal combustion engine through one or more planetary gear(s) to the wheels. The other part is generated as electricity and passes through an electrical variator to assist the driving torque. The latter has the characteristic of poor efficiency. In this simulation study, a comparison among the input power-split, compound power-split, and two mode power-split are discussed. Output power-split is not mentioned in this paper due to its limited applicability in specific vehicles. The idea of selection of the electrical machines is explained: the speed and torque of electrical machines was taken into consideration for the required transmission ratios spread.

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.

This paper summarizes the main considerations in applying a Twin Gyro Controller and the problems in implementing such a controller. Several Twin Gyro Controllers have been built for the purpose of measuring disturbances on a space vehicle, and the construction problems encountered are reported. The main problem areas encountered involved alignment torquing provisions and mechanical tolerances. The three-axis Twin Gyro Controller was spun up to synchronous speed before launch and, as a result, the spinning of the spin stabilized vehicle introduced additional loads on the gyro wheels and torquers. These loads resulted in the use of a spiroid gear drive in the gyro torquer closed loop. Considerations in applying the Twin Gyro Controller as an attitude controller and as a measurement device are covered in terms of sensitivity, accuracy, and limitations.

The intent of this SAE Aerospace Information Report (AIR) is to inform the aerospace industry about various systems available to monitor the inflation pressure or temperature of an aircraft tire. The tire pressure indicating system (TPIS), with cockpit display, is the most widely used of all aircraft tire monitoring systems, and is detailed in this document more than other systems.

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