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Scope of the DRESS project is to research, develop and validate a distributed and redundant electrical steering system technology for an aircraft nose landing gear. The new system aims to: • reduce system weight at aircraft level, replacing the current hydraulic actuation system with an electric one. • improve aircraft safety, achieving higher system redundancy levels compared to the current technology capabilities. This paper presents an outline of different activities occurring in the DRESS project and also shows preliminary results of the new system performance.

Locked wheel protection is an important part of antiskid control for aircraft brake control system. Locked wheel protection compares the wheel speed of two or more wheels, if one of the wheels is too slow, locked wheel protection releases the brake pressure on the slow wheel. This work aims to study the control logic for locked wheel protection. Locked wheel protection control logic consists of 3 key factors: paired wheels, active threshold and inhibit velocity. Focus on comparison different options of these 3 factors, all aspects of control logic for locked wheel protection had been expounded in this study. Simulation and calculation analysis is applied for different locked wheel strategies to evaluate the effect. One conclusion is that the greatest wheel speed of the wheel under control shall be set as a reference speed for locked wheel protection. This study provide the basis to design a proper locked wheel protection function of aircraft brake control system.

Turbine blade fatigue failures began to occur on the Garrett Air Turbine Starter, Model ATS200-58, in commercial airline service. A comprehensive program including metallurgical analysis, finite-element analysis, and strain gage testing of instrumented turbine wheels resulted in large quantities of data on blade vibratory strain. The results of testing various configurations, including the addition of damping and the use of different numbers of stator vanes, are presented.

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.

Elastokinematic parameters of the axle stiffness are one of the important effects for vehicle dynamics, which are usually considered in full-vehicle real-time models. In order to integrate such effects into real-time models, a multibody axle model is placed on the suspension test rig and is clamped at mounting points. Statically defined load cases are applied on the wheel, and finally, lookup tables are generated, which represent the elastokinematics for the real-time environment. In this case, the Body-In-White (BIW) is considered to be ideally stiff. However, the elasticity of BIW significantly influences the elastokinematics behavior as well and should be integrated into real-time models. The present paper introduces an efficient approach to integrate the BIW compliance effects into lookup tables in addition to the suspension stiffness under consideration of the Elastokinematics By Inertia Force method (EBIF method).

The larger chassis space requirements of hybrid vehicles necessitates considerations of the suspension synthesis with limited lateral space, which may involve complex compromises among performance measures related to vehicle ride and handling. This study investigates the influences of suspension linkage geometry on the kinematic and dynamic responses of the vehicle including the wheel load in order to facilitate synthesis of suspension with constrained lateral space. A kineto-dynamic half-car model is formulated incorporating double wishbone suspensions with tire compliance, although the results are limited to kinematic responses alone. An optimal synthesis of the suspension is presented to attain a compromise among the different kinematic performance measures with considerations of lateral space constraints. In the kineto-dynamic model, the struts comprising linear springs and viscous dampers are introduced as force elements.

Targets for reducing emissions and improving energy efficiency present the automotive industry with many challenges. Passenger cars are by far the most common means of personal transport in the developed part of the world, and energy consumption related to personal transportation is predicted to increase significantly in the coming decades. Improved aerodynamic performance of passenger cars will be one of many important areas which will occupy engineers and researchers for the foreseeable future. The significance of wheels and wheel housings is well known today, but the relative importance of the different components has still not been fully investigated. A number of investigations highlighting the importance of proper ground simulation have been published, and recently a number of studies on improved aerodynamic design of the wheel have been presented as well. This study is an investigation of aerodynamic influences of different tires.

With an intense competitive automotive environment, it becomes imperative for any OEM to launch their products into the market in a short span of time & with a ‘First Time Right’ approach. Within the current scenario in the Automotive Industry, the selection of optimum set of hard points and wheel geometry often becomes an iterative or a trial-and-error process which is both time consuming and involves higher development cost as there may be instances where 2 to 3 sets of iterations are needed before specification is finalized for production. Through this paper, an attempt has been made to develop a methodology for deciding wheel geometry parameters (covered in the later section of this paper like Caster, Camber, Mechanical trail, etc.) [1, 2, 3, 4] for a three wheeled vehicle as a First Time Right (FTR) approach to cut down on conventional, expensive & time-consuming iterative approach.

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.

Based on a study of a Mobile Pressurized Laboratory (MPL) concept made during the European Mars Mission Architecture Study conducted for ESA, further design development of the laboratory and interior functional layout of the rover has been performed. This includes volume optimization, wheel system and geometry, interior layout and functional zoning, airlock placement and ergonomics, radiation protection, ergonomic detailing of habitation functions like sleep, kitchen, hygiene, ergonomics of work environment for driver, glove box, laboratory and storage systems and spatial flexibility and adaptability. The large wheel concept proposed in the ESA study to maximize habitable volume is further investigated. Additionally, omni-directional wheels have been introduced to the design to improve the vehicle's manoeuvrability. The inclusion of new design features led to a decision to rename the concept, MarsCruiserOne (MCO). The paper describes the design of the MCO.

This paper studies the design and selection of the reduction ratio to be used in the transmission of a solar powered vehicle. A single degree of freedom vehicle model is presented in which the equation of motion for the longitudinal direction is obtained. The equation may be expressed in the form given below: Where PTractive is the tractive force produced at the tire ground contact; ma is the inertial acceleration force; FR is the sum of all forces, of first order magnitude, contributing to rolling resistance and Fa is the aerodynamic resistance force. The equation may be expressed as a function of the reduction ratio, characteristics of the motor (rpm), available acceleration, wheel and tire used. This problem was solved by iterative methods using a spreadsheet. When the acceleration is zero the maximum velocity may be obtained. When the the velocity tends to zero the maximum torque is determined. This however, is constrained by the power characteristics of the motor.

An aircraft braking system thermal modeling approach which provides a high degree of temperature resolution has been developed. This finite element method (FEM) based approach has been successfully employed to model the transient, non-linear thermal response of a large aircraft wheel and carbon brake assembly during and after a braking event. Commercially available software was utilized for graphics based model pre and post processing and generation of the FEM analysis results. Temperature distributions were determined at a level of detail much greater than that available from existing system thermal models. Good agreement between the model predictions and measured temperature histories from a dynamometer test using full scale braking system hardware was obtained.

The pocket rocket definition is a small vehicle with a bigger engine. The result is a vehicle with better acceleration, top speed and speed recovery. This extra performance must be followed by improved lateral and longitudinal grip, faster steering response and also upgraded brakes. Based on a 1.0L popular vehicle, several changes were performed, transforming this family oriented vehicle in an enjoyable small sports car. The engine was changed to a production 1.8L, followed by upgrades in transmission, suspension, wheel & tires, brakes and powertrain integration.

Transportation aspects of commercial spaceflight in the opening decades of the Twenty-first Century are envisioned. A specific Spaceliner concept is described, one predicated on combined-cycle airbreathing/rocket (“Synerjet”) propulsion. Its technical literature recorded heritage is reviewed. NASA's long-term goals, and its ongoing program relevant to this class of transportation concepts are discussed. A key observation, one of potentially distant, but great significance to the future of aviation and the air carrier industry, is that Spaceliner class systems, once available, can -- in addition to providing orbital payload service -- fly transglobally, conducting point-to-point terrestrial transportation services, all at ‘highest speed.” Providing an aviation/air-carrier perspective on all of this, in an annex paper attached, the candid views of an esteemed former airlines executive, the late Willis Player, are highlighted.

The purpose of this research is to characterize the wear resistance of wheel treads made of polymeric woven and non-woven fabrics. Experimental research is used to characterize two wear mechanisms: (1) external wear due to large sliding between the tread and rocks, and (2) external wear due to small sliding between the tread and abrasive sand. Experimental setups include an abrasion tester and a small-scale merry-go-round where the tread is attached to a deformable rolling wheel. The wear resistance is characterized using various measures including, quantitatively, by the number of cycles to failure, and qualitatively, by micro-visual inspection of the fibers’ surface. This paper describes the issues related to each experiment and discusses the results obtained with different polymeric materials, fabric densities and sizes. The predominant wear mechanism is identified and should then be used as one of the criteria for further design of the tread.

This paper entails the design and development of a NASA testing system used to simulate wheel operation in a lunar environment under different loading conditions. The test system was developed to test the design of advanced nonpneumatic wheels to be used on the NASA All-Terrain Hex-Legged Extra-Terrestrial Explorer (ATHLETE). The ATHLETE, allowing for easy maneuverability around the lunar surface, provides the capability for many research and exploration opportunities on the lunar surface that were not previously possible. Each leg, having six degrees of freedom, allows the ATHLETE to accomplish many tasks not available on other extra-terrestrial exploration platforms. The robotic vehicle is expected to last longer than previous lunar rovers.

The moment at which a wheel of a landing aircraft touches the ground, the wheel meets great resistance to forward motion. As the undercarriage absorbs almost none of this longitudinal impact, the tire begins to smoke, while the oleo strut undergoes spin up and spring back. Most people are unaware that this phenomenon represents the technological limits of current suspensions. For the wheel to absorb forward impact, it must be given longitudinal stroke. We have created a new type of undercarriage, containing a crank element and adequately gives the longitudinal stroke (1),(2). We clarified the new undercarriage with basic dynamical analysis and computer simulations using an aircraft model with 1 degree of freedom. This simulation showed that when given specific freedom of circular motion, the wheel will accelerate in two stages after landing. Consequently, the sliding friction work on the tire is reduced by a maximum of about 47.4%.

An ergonomics study was conducted in a mock-up with a fixed steering wheel position. Drivers adjusted the seat and pedals to a comfortable position. A three-dimensional coordinate measurement machine (CMM) was used to measure the comfortable position of 21 participants. Proven test methods were used to collect the posture data. A model is described to assist in seat and pedal placement for cockpit design.

Sandstalker is a manned, unpressurized vehicle that is designed for first exploration of Mars. It is a design study to outline another point of view considering mars exploration vehicles. It is designed to transport two astronauts and special scientific equipment to destinations up to a radius of 25 miles. It is a foldable and lightweight construction, so the transport in an average NASA transportation box is possible. The ability to move easily and safely across the martian surface results from the new construction of the wheels, the wheel arrangement and the wheel suspension. The spider-like structure of the vehicle offers an extreme maneuverability and supports the concept of an all-terrain vehicle able to surcome many different surface obstacles. The reduction of weight, improvement of the wheels and the seats in particular represents the main tasks of M.A.T.V.

What was always referred to as pilot error or human error is now considered to be an error by the organization that trained (or failed to train) the operator or front-line person. Although mistakes due to human error will never be completely eradicated, every attempt must be made to reduce these errors to their lowest possible number. Unfortunately, changing human behavior is difficult at best. The typical aviation safety training program does not use all available strategies to make these needed changes in behavior. Even one small omission can dramatically reduce the effectiveness of a training program. Instead of cranking out hour after hour of traditional lecture-type training, changes must be made in methodology and techniques. The training wheel is continually cranked, but whether it does any good is usually “hoped for” and guessed at. Aviation safety training is, for so much time and effort, a failure in motion.