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The University of Texas Center for Electro-mechanics (UT-CEM) has been developing active suspension technology for high-speed off-road applications since 1993. The UT-CEM system uses controlled electromechanical actuators to control vehicle dynamics with passive springs to support vehicle static weight. The program is currently in a full vehicle demonstration phase on a military high mobility multipurpose wheeled vehicle (HMMWV). This paper presents detailed test results for this demonstration vehicle, compared to the conventional passive HMMWV, in a series of tests conducted by the U.S. Army at Yuma Proving Grounds. Extensive data in plotted form are discussed, including accelerometer readings from 6 vehicle mounted accelerometers, corner displacement transducers, and current and power plots for the actuators.

The use of electromechanical actuators for an active suspension on a main battle tank is investigated. A novel approach to the development of the active suspension control algorithms is presented along with simulation results to evaluate the electromechanical design requirements. The optimal electromechanical actuator design is described along with simulated performance results for a one roadwheel station electromechanical active suspension. Follow-up plans for the laboratory testing of a single wheel station system are also included.

The combination of an inherently robust asynchronous (induction) electrical machine with the rapid control of energy provided by a high frequency resonant ac link enables the efficient management of higher power levels with greater versatility. This could have a variety of applications from launch vehicles to all-electric automobiles. These types of systems utilize a machine which is operated by independent control of both the voltage and frequency. This is made possible by using an indirect field-oriented control method which allows instantaneous torque control in all four operating quadrants. Incorporating the ac link allows the converter in these systems to switch at the zero crossing of every half cycle of the ac waveform. This “zero loss” switching of the link allows rapid energy variations to be achieved without the usual frequency proportional switching loss.

Power modules are used to operate three-phase alternating current motors in hybrid vehicles and electric vehicles. Good fuel efficiency and high power density are required in the field of hybrid vehicles. To achieve this goal, the miniaturization of the power module will be necessary. This trend may make a current density, which is created by insulated gate bipolar transistors (IGBTs) and free wheel diodes (FWDs), higher in power modules. Solder is often used as the joint material of power modules. It is known that a current density larger than 10 kA/cm2 causes solder electromigration. This phenomenon may cause delamination of the joint area. In addition, the ambient temperature has an influence on electromigration. The temperature of an engine compartment is high, so it is likely to cause electromigration. However, the current density of the double-sided cooling power modules in 2007 with solder joint is lower than 0.4 kA/cm2, and this value is lower than 10 kA/cm2.

Lateral head motions, torso motions, lateral neck bending angles, and electromyographic (EMG) activity patterns of five human volunteer passengers are compared to lateral motions of a Hybrid III ATD during right-left and left-right fishhook steering maneuvers leading to vehicular tip-up. While the ATD maintained relatively fixed lateral neck angles, live subjects leaned their heads slightly inward and actively utilized their neck musculature to stiffen their necks against the lateral inertial loads. Except for differences in neck lateral bending, the Hybrid III ATD reasonably reflects occupant kinematics during the pre-trip phase of on-road rollovers.

Tomorrow's vehicles will offer increased comfort and luxury features to drivers. These features will require the use of additional electrical circuits within the same space that is available in today's vehicles. In order to meet these requirements, a new, compact, high temperature wire design will be required. Insulation utilizing electron beam cured polyethylene offers the required product features, while also offering the processability required for this type of wire. This paper will address why this material is best suited for this task, describe how a product of this type can be evaluated, and provide a comparison between a compound of this type and the current industry standard.

In the frame of military programmes, AEROSPATIALE, developed, for ballistic missiles (motor cases wound structures), an original process of composites curing. This process, now utilized on an industrial basis is the Electron Beam Curing (EBC, sometimes called ionization, or irradiation curing). EBC is based on the composite's resin polymerization caused by its exposure under a powerful enough electron beam. Originally, this process was developed for costs saving reasons, as an economical alternative to the conventional thermal curing process. This objective having been achieved, an other incentive was found to the use of such a technology. As a matter of fact, this process offers the outstanding advantage of being a “room temperature” process. The electron beam acts directly on resins molecular structure to bring about its polymerization, no heating of the part is necessary.

Electron beam curing is a very fast, non-thermal curing method that uses high energy electrons and/or X-rays as ionizing radiation at controlled rates to cure polymer matrix composites, making them more affordable. A number of programs and initiatives are now actively evaluating the materials and processes for applications as varied as next generation aircraft, space transportation, military ground vehicles, and others. This technology offers a variety of potential benefits to the transportation industry.

This paper discusses electron beams and their generation, configuration of electron beams used for welding, sources for electron beam information and manufacturers of electron beam welding machines, tooling for electron beam welding, accomplishments with electron beams in joining aerospace materials, and the future of electron beams in welding technology.

The characteristics and advantages of electron beam welding using both vacuum and nonvacuum techniques are discussed and related to the use of this process in production. Specific applications of both techniques are selected and described in detail as a means of evaluating this process relative to quality, versatility, controllability, adaptability for automation, and economics.

Some of the characteristics of electron beam welding are presented which can be exploited by the design engineer, together with precautionary notes on limitations. Specific examples of electron beam welded aircraft components arecited.

The conversion from submerged arc welding to electron beam welding (EBW) of transmission components at Clark Equipment Co. is described. The latter system permits the consistent holding of close tolerances and the obtaining of controllable and repeatable metallurgical structures. In addition, control of the weld and distortions is increased, and weld joints are made feasible in otherwise inaccessible locations. A brief history is presented which touches on the selection of transmission products for EBW, choice of EBW equipment, preliminary evaluation, and acceptance of the process by personnel. Then, the application of EBW to production parts is discussed.

A new concept is described that permits the electron beam process to be used for final assembly welding of large production parts. With this concept, 70 ft long production joints are being welded by North American Aviation. Using a relatively small portable vacuum chamber that fits on top of the parts to be welded, just the area around the joint is evacuated. Specially designed seals allow the electron gun, mounted on a lid, to slide along the top of the chamber, making 5 ft long runs at speeds up to 60 in./minute.

An electron beam welding process, evolved from its primary use in research and development laboratories to a production method that now gives design and manufacturing engineers a proven means of fabricating large complex structural members of the type used in the aircraft and aerospace industries, is the subject of this paper. Using this method of fabrication, many large complex forgings can be replaced with simpler and less expensive fabricated sections. In a number of applications, these forgings can now be replaced by two or more smaller simpler forgings; smaller forging used in conjunction with standard rolled sections; or assemblies made completely of rolled sections. Large assemblies which are beyond the capability of most forging presses can also be fabricated by the electron beam welding process.

An electronic accelerator pedal has been designed for use on heavy trucks with on-board electronics requiring accelerator position input. The one-piece assembly is a floor mounted treadle design with all required electronics and wiring protected behind the instrument panel. The assembly also has been designed to operate, or be operated by, mechanical devices outside of the cab. It is these features, and others, which allow this assembly to satisfy the concerns and needs of all activities which must interface with the accelerator system.

During the past few years, a combination of political, economic, social, and technological factors have created a new interest in the diagnosis and repair of automobiles. The field received considerable publicity with the introduction by Volkswagen in 1972 of a limited diagnostic system. We find that most auto manufacturers today are either considering or planning to introduce similar systems. This presentation will review some of the systems that have been developed and discuss some possible approaches for the future.

The wide angle air core tachometer has been developed as an alternative to the D'Arsonval type tachometer. Differences between the air core mechanism and D'Arsonval meter movement have forced the design of new drive electronic circuitry which would transform a linear output voltage to two bi-directional output wave forms. Combination of the new circuit and existing gage assembly is built into a tachometer assembly and is being produced in high volume utilizing automated assembly and computerized laser test and adjust equipment. Expansion of the concept will allow application to pressure and temperature gages, pyrometers, speedometers, etc.

The isolation diode discussed in this paper has been developed to provide a simple and reliable switch between the output of the alternator and the storage battery of a car. Its function is to block any flow of current from the battery back to the alternator and at the same time to permit use of the popular charge indicator light. This alternator charging system successfully employs electronic principles in converting alternating current to direct current and in giving complete control of field current without the contact points found in the conventional vibrator type regulator.

It is presented here a specific Instrumentation System to determine the quality of materials. It is based in temperature, resistivity and permittivity inputs to determine the title and density of hydrated ethyl alcohol. It is described a physic modeling, development and experimentation. The presented results seen agree with the proposal. The resulted are integrating at computational unit, permitting application static and dynamic.

AIRPLANE hydraulic braking systems must be designed to have the highest standard of performance without sacrificing reliability. By the use of a multielement oscillograph the various characteristics of the braking system can be recorded simultaneously so that the value of design changes can easily be determined. Oscillograms for a typical aircraft braking system show that relatively minor changes result in a wide differential in performance and emphasize the conclusion that design changes in a hydraulic brake system should be evaluated with the oscillograph.