Search Results

Gradient magnetically assisted fluidized bed (G-MAFB) methods are under development for the decomposition of solid waste materials in microgravity and hypogravity environments. The G-MAFB has been demonstrated in both laboratory and microgravity flight experiments. In this paper we summarize the results of gasification reactions conducted under a variety of conditions, including: combustion, pyrolysis (thermal decomposition), and steam reforming with and without oxygen addition. Wheat straw, representing a typical inedible plant biomass fraction, was chosen for this study because it is significantly more difficult to gasify than many other typical forms of solid waste such as food scraps, feces, and paper. In these experiments, major gasification products were quantified, including: ash, char, tar, carbon monoxide, carbon dioxide, methane, oxygen, and hydrogen.

Soft magnetic cores of electric motors and generators are normally manufactured by stamping individual circular laminates from non-oriented electrical steel (NOES) sheets and stacking them layer by layer to reach the required height. The traditional lamination method can only achieve the average performance of the NOES since the magnetization is in all the directions of the sheet plane. Although NOES is ideal to have isotropic magnetic properties in all the directions of the sheet plane, commercially available electrical steel sheets always show apparent anisotropy in the rotating magnetization directions lying in the sheet plane. The anisotropy in magnetic properties not only causes fluctuations in the rotating magnetic field, but also leads to oscillations in electromagnetic torque, and thus needs to be minimized.

Magnetite and graphite are very common phases present on the surface of polymer-matrix composite (PMC) and cast iron disc/drum couples in run in automotive brakes. Considering that some manufacturers use magnetite as raw material in their products this work investigates the generation of magnetite found in the third body as a process of tribo-reaction. Simplified brake pad and brake linings compositions without magnetite were produced and tested using the Brake Lining Quality Control Test Procedure - SAE J661 . After testing the surfaces were observed with Glancing Incidence X-ray Diffraction (GIXRD), Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray spectrometry (EDX) and Micro-Raman spectroscopy. Results showed regions containing magnetite on the steel/glass fibers.

Anti-lock braking systems (ABS) are an accident evasion system (AES) that by incorporating relevant sensory systems (SS), for instance, such as magneto-optic (M-O) tachometers, accelerometers etc., can avoid wheel locking during hard braking in an emergency, especially when the road surface is slippery. Automotive vehicles (AV) lose steering when the front wheels (FW) lock. An ABS uses sensors at each wheel to monitor deceleration when the fluidomechanic (F-M) or electromechanic (E-M) drum, ring or disc brakes are applied. If any of the wheels begin to lock, the ABS will modulate the brake pressure or voltage, thus ‘pumping’ the fluidomechanic (F-M) or electromechanic (E-M) drum, ring or disc brakes, respectively, at the rate faster than the average human driver (HD) could. This will allow the wheel to continue rotating so avoiding locking, and the wheel will remain to react to the steering wheel (SW).

This paper describes a Magneto-Rheological coupling based Hydraulic Power Steering (MRHPS) system developed for improving fuel economy in conventional vehicles. The MRHPS system reduces the parasitic losses associated with the power steering pump and improves fuel economy in full-size trucks (and SUVs) by up to 3%, while maintaining the production hydraulic power steering system performance. The MRHPS is a low cost alternative to electric power steering and electro-hydraulic power steering systems and requires significantly less electric power while resulting in similar fuel economy gains. With the MR coupling the power steering pump is run at optimum speeds depending on the steering angle, angle rate and vehicle speed, and the pump is run in closed loop speed control mode so that factors like temperature, manufacturing tolerances, aging, etc. will not degrade the steering performance.

A Magneto-Rheological (MR) Fluid Semiactive Suspension System was tested on a Stryker vehicle, Infantry Carrier Variant (ICV), to determine the performance improvements compared to a standard ICV Stryker vehicle. In January 2005, the testing was conducted at the U.S. Army Yuma Proving Grounds located in Yuma, Arizona. The testing was conducted under the guidance of the U.S. Army Tank-Automotive Research, Development, and Engineering Center (TARDEC) of Warren, Michigan and MillenWorks of Tustin, California. The core of the system tested is comprised of 8 dampers and controllers using proprietary algorithms to modulate individual wheel forces in response to terrain inputs and body motion. Functionality of the Standard Stryker vehicle’s pressurized gas spring and ride height management system was fully retained while maintaining the physical envelope of the original damper.

A Magnetoelastic based Non-Contacting, Non-Compliant Torque Sensor is being developed by Siemens VDO for automotive transmission applications. Such a sensor would benefit the automotive industry by providing the feedback needed for precise computer control of transmission gear shifting under a wide range of road conditions and would also facilitate cross-platform usage of a common transmission unit. Siemens VDO has prototyped transmission torque sensors operating on the principle of Inverse-magnetostriction, also referred to as the Inverse-Joule Effect and the Villari Effect. Magnetostriction, first documented in the mid 1800's, is a structural property of matter that defines a material's dimensional changes as a result of exposure to a magnetic field. Magnetostriction is caused when the atoms that constitute a material reorient in order to align their magnetic moments with an external magnetic field.

For the measurement and control of angular position or rotational speed in automobiles, the environmental conditions have led manufacturers to mainly specify magnetic sensors. They are able to withstand high shock and vibration, the presence of oil, dust or salt spray, and can operate over a temperature range as wide as -40°C to +150°C. Magnetic sensors generally meet these goals better than optical devices. Increasingly, though, modern engine control requirements call for much higher resolutions, and this paper describes how the environmental conditions are accomplished in a high resolution magnetic device. Three different configurations that are applicable to automobiles are described: a stand-alone encoder mounting to a stub shaft, a stand-alone encoder mounting over a through shaft, and a modular encoder comprising independent encoder wheel and sensor components.

It has become the need of the day for the evolution of newer and better technologies for various applications. In this paper we introduce a new technique of recovering the kinetic energy which is wasted during the process of braking in Formula one cars. In previous techniques of kinetic energy recovery, the kinetic energy is converted to electrical energy which is stored and later utilized. In this paper we propose a new approach of recovering the energy wasted due to braking by using a flywheel mechanism coupled through magnetorheological(MR) fluid. During the process of braking, the energy is transferred from the wheel to the flywheel(recovery) and during the process of acceleration the energy is transferred from the flywheel to the wheel(reuse). Due to this recovery of energy there is an improved acceleration and a comparatively lesser fuel consumption.

Paper introduces a new type of small displacement sensor. It has the characteristics of high sensitivety, high pressure resistant, non-contact type etc. The sensor was used in measuring the displacement of the valve cone of a cartridge valve and the results were fairly satisfied.

The Magnetostrictive Dynamic Strain Sensor is a permanent-magnet constant-flux excitation sensor and thus requires no other electrical excitation or power source. It does not require any signal conditioning. Since it is a constant-flux dynamic sensor, it does not generate any offset voltage and it does not exhibit temperature or drift problems. Furthermore, the sensor is rugged, simple and inexpensive. The sensor's time-averaged output is constantly zero. The sensor detects only dynamic events such as impact, crash, firing (or misfiring) of an engine cylinder, piston slap, vibrations of a machine component, vehicles passing through a bridge, etc. Therefore, the sensor has many promising automotive applications including crash and misfire detection.

Intense worldwide activity is currently focused on development of magnetostrictive torque sensors. The sensors are both non-contact and provide high sensitivity in combination with robustness. They are therefore prime candidates for use in torque-feedback closed-loop controls of automotive engines and transmissions. Previously, both linear and nonlinear analyses of the branch-design of magnetostrictive torque sensors were given. This paper goes beyond prior work to include cross-design and solenoidal-design sensors (designs that are more commonly used). For each sensor design: general models are derived, equivalent electrical and magnetic circuits are developed, and equations governing signal outputs are given. A comparison is done of magnetic circuit operating behavior for sensors designed to fit into the same space on a shaft made of maraging steel.

It is shown that the measured materials property of magnetostriction affects sensor output signal in two fundamentally different ways. The dual influence of magnetostriction on sensor output signal has heretofore not been reported. Five different methods of torque measurement signal detection are identified. For each of these detection methods, equations governing signal output are derived and are discussed. It is found that certain signal detection methods have both superior signal-to-noise performance and minimum sensitivity to variation of air gap. These detection methods are identified in the paper. Six sensor design configurations are analyzed. In the limit of miniature-size sensor design; performances of all signal detection methods are shown to deteriorate as a consequence of effects due to increased cross-leakage of flux between poles.

Current worldwide development activity and potential markets for magnetostrictive, noncontact, torque sensors are reviewed first. Then, a general model for the sensor is derived, and equivalent electrical and magnetic circuits for the sensor are developed. The model is defined in terms of a basic single-branch magnetostrictive sensor element, combinations of which serve as models for multi-branch sensors. Key assumptions are made that permit simplification of model equations. Procedures for reliable evaluation of magnetic permeance parameters (essential for insuring accuracy of the model) are also given. Physical origins of the sensor output signal are described, and discussion of characteristic behavior of magnetostrictive sensing-member materials are given. It is shown that all practical sensors include some means of compensation to average out characteristic nonideal properties of magnetostrictive sensing materials.

A highly sensitive, non-contact torque sensor was developed using amorphous magnetic alloy. A thin strip of amorphous magnetic alloy was bonded onto the surface of the shaft, formed into a chevron shape, then the torque applied to the shaft was detected from the difference in the inductance of the detection coil wound around the strip. A highly sensitive torque sensor having outstanding linearity could be made by selecting a magnetic working point and stress working point to apply to the amorphous magnetic alloy and by optimum arrangement of the heat treatment and bonding processes. Temperature characteristics, twist resistivity, and noise resistivity were also evaluated to prove performance in practical use.

In electric motors the working torque results from the magnetic forces (due to the magnetic field). The magnetic forces are also a direct source of structural excitation; further, the magnetic field is an indirect source of structural excitation in the form of magnetostriction. In the last decade other sources of structural excitation (e.g. mechanical imbalance, natural dynamics of the electric motor) have been widely researched and are well understood. On the other hand, the excitation due to the magnetic forces and magnetostriction is gaining interest in the last period; especially in the field of auto-mobility. Due to the broadband properties of the magnetic field (e.g. Pulse-Width-Modulation(PWM), multi-harmonic excitation), the direct structural excitation in the form of magnetic forces is also broadband.

The study was aimed at designing a system for measuring the strength H of magnetic field surrounding a ferromagnetic specimen subjected to cyclic (or static) loading. A new type of camera for monitoring the magnetic picture of specimen was constructed. The measurement principle is based on the reverse magnetostriction effect (also called the Villari effect). No external magnetizing field is assumed; the entire magnetic effect is due sollely to cyclic mechanical loading. The measuring arrangement is best suted for examining plane stress cases. The measuring set—up is made up a precision computer controlled X–Y positioner and a basis unit whose main element is a single magnetoresistor or an array of magnetoresistors. A digital processing system yields a quasi-continuous magnetic image of an object.

Most mail moves by surface transportation modes. As materials handling systems and intermodal transportation capabilities improve, mail moving more than 600 miles should go by air. 1.4 billion ton-miles of traffic a year are waiting for an imaginative and economical air transportation proposal. The U. S. Postal Service has been pushing hard to get more mail in the air, despite strong opposition or lack of interest by airlines. The time for an intensive marketing approach to mail, by airlines, is overdue.

Currently The European Union has been considered the best example in pedestrian protection. Since the 70s, the European Parliament together with research institutes and the automotive industry have been studying and developing methods to improve adjusted road structure, have also conducted studies on biomechanics applied to the subject, medical structure and required modifications in the vehicles. Although it has been considered the best example, during 2004 in Europe (IRTAD)[1] about 39250 fatalities occurred in traffic situation. About 6900 (17,6%) of these were pedestrians and 2650 (6,7%) were bicyclists. During 2004 in Japan (IRTAD) about 8500 fatalities occurred in traffic. About 2600 (30,7%) of these were pedestrians and 1150 (13,5%) were bicyclists. The injury frequency of the pedestrian body segments has been investigated since the 60s and the head and the lower extremities have been found the most frequently injured.

The main classification of Electric Parking Brakes (EPB) can be made into cable puller and caliper integrated types. In this paper, the main design considerations that need to be made for each type of system will be examined. In terms of mechanical design, actuator design factors including target capacity, system size, and vehicle mounting will be briefly discussed. In terms of software, a unified software structure that can incorporate both types of EPBs will be introduced. This unified approach, made up of fixed and variable modules, allows for more efficient software development for both types of EPB systems. The fixed modules are related to the identical target functions regardless of EPB type, while the variable modules are made up of the different considerations that need to be made depending on the EPB type in order to meet such targets. Finally, some test results of target functions for both types of EPB systems will be given.