Search

Automated solutions for manufacturing composite products based on prepreg often imply Automatic Fiber Placement or Automatic Tape Laying. These systems are generally associated with huge investments. For certain manufacturing applications it is interesting to investigate alternatives to find simpler and less costly automation. One example of an automated system could be the use of a standard industrial robot to pick single prepreg plies from an automated cutting machine and stack them to form a plane laminate. This paper is based on a case illustrating a product from the aircraft manufacturing industry. The case will demonstrate a pick and place concept on a general level and illustrate challenges that must be solved. The challenge selected to be the main focus for this paper is an automated process for backing paper removal. A literature review of different gripping technologies reveals several interesting technologies, and the most promising are tested for backing paper removal. The tests show that an automated removal process can be designed by using standard vacuum grippers in combination with mechanical clamping grippers. In order to lift the backing paper with a vacuum gripper an initial separation between the backing paper and prepreg is needed. This separation is most easily mechanically induced by bending the material. The proposed solution for automatic backing paper removal can be integrated in a manufacturing cell for manufacturing of the studied product. SAE Technical Paper 2013-01-2289

The Advanced Extra-vehicular Activity (EVA) team of the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) Crew and Thermal Systems Division (CTSD) participated in the Desert Research and Technology Study (RATS) in September 2003, at Meteor Crater, AZ. The Desert RATS is an integrated remote field site te t with team members from several NASA centers (Johnson Space Center; Glenn and Ames Research Centers) and universities (Bowling Green State University, University of Cincinnati, Massachusetts Institute of Technology) participating. Each week of the two-week field test had a primary focus. The primary test hardware for the first week was the I-Gravity Lunar Rover Training Vehicle, or Grover, which was on loan to NASA from the United States Geological Survey (USGS) Astrogeology Research Program. The 2003 Grover driving test results serve as a rover performance characterization baseline for the Science, Crew, Operation and Utility Testbed (SCOUT) project team, which will be designing and fabricating a next generation roving vehicle prototype in Fiscal Year (FY) 2004. The second week of testing focused on EVA geologic traverses that utilized a geologic sample field analysis science trailer and also focused on human-robotic interaction between the suited subjects and the EVA Robotic Assistant (ERA). This paper will review the Advanced EVA team's role in the context of the overall Desert RATS, as well as the EVA team results and lessons learned. For information regarding other test participants' results, the authors can refer interested parties to the test reports produced by those Desert RATS teams.

Progres dans la conception et la fabrication de materiaux de friction en papier pour lourdes charges

Recently introduced sulfur caps on marine fuels in so-called sulfur emission control areas (SECAs) are forcing shipping companies to sail on more or less automotive grade diesel in lieu of the considerably less expensive, but sulfur-laden heavy fuel oil (HFO) to which they were accustomed. This development is an opportunity for a bio-based substitute, given that most biomass is sulfur free by default. Moreover, given that biomass is typically solid to start with, cracking it to an HFO grade, which is highly viscous in nature, will involve fewer and/or less harsh process steps than would be the case if an automotive grade fuel were to be targeted. In this study, a renewable low sulfur heavy fuel oil (LSHFO) has been produced by means of subcritical water assisted lignin depolymerization in the presence of a short length surfactant, ethylene glycol monobutyl ether (EGBE). The resulting oil contains a lignin derived content of 75 wt.-%, with the remainder consisting of EGBE and water (reusable). The derived LSHFO has a 20% higher heating value than the lignin feedstock. It is still roughly 20% and 30% lower when compared to the HFO and low sulfur marine gas oil (LSMGO) benchmarks, respectively. The lower heating value can be attributed to the fuel bond oxygen (10%) and water present in the LSHFO. Viscosity and sulfur levels, however, are within the HFO and LSMGO range and target respectively. Future work will examine what impact lignin particle size and surfactant type/concentration will have on the results.Graphical abstract

This paper clarifies aggressivity reduction approach for MPV, Multi-Purpose Vehicles, derived from large passenger vehicles toward small passenger vehicles. The effects of aggressivity-reducing approach were measured through full-frontal rigid barrier crash simulations with TRL aluminum honeycomb by Finite Element Method. The front-end structures of large vehicles studied in this paper based on this aggressivity reduction approach show good front-end homogeneity and low average height of force. The structures were also found to effectively reduce aggressivity toward small vehicles by car-to-car simulation. However, there are some cases where the effect was influenced by overlap ratios. From this result, overlap ratio is considered to be one of the important factors to improve compatibility performance.

Increased environmental awareness and depletion of fossil fuel resources are driving industry to develop alternative fuels that are environmentally more acceptable. Vegetable oils are potential alternative fuels. Vegetable oils in India are produced from numerous oilseed crops. While all vegetable oils have high energy content, most require some processing to ensure safe usage in internal combustion engines. Most detrimental properties of oils are its high viscosity, low volatility and polyunsaturated character. The most widely used method is to convert vegetable oils into biodiesel. Biodiesel fuels are primary esters, which are produced by transesterifcation of vegetable oils. Several vegetable oil esters have been investigated so far in different parts of the world and found suitable to be used in diesel engines. In present investigation, methyl esters of some non-edible vegetable oils of Indian origin (castor, linseed and ricebran) are prepared and their properties have been evaluated. The effect of temperature on the viscosity of vegetable oils and their esters was studied. Viscosity of vegetable oils drastically decreases after transesterification. Flash point and specific gravity of neat ricebran and linseed oil and their esters were also evaluated in this investigation. Introduction Increased environmental concerns, tougher clean air standards, increasing prices and uncertainties concerning petroleum availability necessitate the search for a viable alternative fuel, which is more environment friendly, hence vegetable fuel studies have become prominent among various potential alternatives. The idea of using vegetable oils as fuel for diesel engine is not new. When Rudolf diesel first invented t he diesel engine, he demonstrated it at the 1900 world exhibition in Paris, employing peanut oil and said “The use of vegetable oils for engine fuels may seem insignificant today, but such oils may become in course of time as important as petroleum and the coal tar products of the present time” [1]. In the 1930’s and 1940’s, vegetable oils were used as diesel fuels from time to time, but usually only in emergency situations. Recently, because of increase in crude oil prices, limited resources of fossil fuels and environmental concerns, there has been a renewed focus on vegetable oils and animal fats to make biodiesel fuels. Biodiesel is biodegradable, non-toxic and essentially free from sulphur. It is renewable and can be produced from agriculture & plant resources. While short-term tests are positive, long-term usage of neat vegetable oils or their blends with diesel leads to various engine problems such as injector coking, ring sticking, injector deposits etc. [2,3]. High viscosity, low volatility and a tendency to polymerize within the cylinder are the root cause of many problems associated with direct usage of these oils as fuels [2]. The process of transesterification yields vegetable oil esters, which have shown promise as alternative diesel fuel as a result of improved viscosity & volatility characteristics. Several researchers investigate the different vegetable oil esters [3-7] and found esters comparable to diesel fuel. Muniyappa et. al., optimized the transesterification process for Soyabean oil, [3] . Freedman et. al. investigated the effect of various parameters on vegetable oil yield [4]. Several researchers transesterified the vegetable oils and found that properties are quite comparable to mineral diesel and performance and emission characteristics of CI engines using biodiesel in different proportion as a blend with mineral diesel improves [5-10]. Agarwal et.al. developed linseed oil methyl esters and found it comparable to diesel with improved emission characteristics compared to diesel [5,6]. Physical wear of various vital parts, injector coking, carbon deposits etc. were found to be substantially lower in case of 20% biodiesel fuelled engines [11]. The objective of this study is to investigate the effect of transesterifcation on the viscosity and other properties of non-edible vegetable oils of Indian origin and to evaluate the effect of temperature on the viscosity of neat vegetable oil and their methyl esters. Detailed results on the viscosity and other properties of oils and their esters are presented in this paper. Composition of Vegetable Oils Petroleum diesel fuel is a complex mixture of hydrocarbons with carbon atoms ranging between 12-18, whereas vegetable oils are mixture of organic compounds ranging from simple straight chain compound to complex structure of proteins and fat-soluble vitamins and are commonly referred as triglycerides. Vegetable oils are usually triglycerides, generally with number of branched chains of different length, and have structural notation as shown.

This paper describes the simultaneous reduction of nitrogen oxides (NOx) and particulate matter (PM) in a modern light-duty diesel engine under high exhaust gas recirculation (EGR) levels. Simultaneous reduction of NOx and PM emissions was observed under lean conditions at several low to moderate load conditions using two different approaches. The first approach utilizes a throttle to increase EGR rate beyond the maximum rate possible with sole use of the EGR valve for a particular engine condition. The second approach does not use a throttle, but rather uses a combination of EGR and manipulation of injection parameters. A significant reduction in particulate matter size and concentration was observed corresponding to the reduction in particulate mass. This PM reduction was accompanied by a significant shift in the heat release profile. In addition, there were significant cylinder-to-cylinder variations in particulate matter characteristics, gaseous emissions, and heat release. A fuel penalty is associated with operating in the low NOx and low PM regime when there are no modifications to the injection strategy. Preliminary experiments indicate that the penalty can be eliminated or reduced to a few percent while still maintaining a significant reduction in NOx and PM. An improved understanding of this combustion regime will lead to improved EGR utilization for lowering the performance requirements of post-combustion emissions controls.

A comparison of the NHTSA advanced dummy and the Hybrid III is presented in this paper based on their performance in repeated sled tests under 3 different restraint systems. The restraint systems considered are: the airbag alone, the 3-point belt alone, and a combined use of the airbag and the 3-point belt. Various time-histories pertaining to accelerations, angular velocities, deflections and forces have been compared between the two dummies in order to study their repeatability. The Hybrid III appears to be more repeatable than the NHTSA advanced dummy in its response in one case, that of restraint with the 3-point belt alone. The response of the NHTSA advanced dummy in two other restraint modes, the airbag alone and the combination of 3-point belt and airbag, appears to be no less repeatable than that of Hybrid III in this series of tests. The variability in the sled pulse appears to mask the differences, if any, in the variability of response between the two dummies in two later cases. Under some restraint configurations, for some body segments, the NHTSA advanced dummy appears to show better repeatability. In addition, it appears that the read-out of the chest-deflection measurement system in the NHTSA advanced dummy is not well defined because it is influenced by the rotation of the upper spine relative to the lower spine. (A) For the covering abstract see ITRD E106439.

Exhaust gas recirculation (EGR) cooler fouling has emerged as an important issue in diesel engine development. Uncertainty about the level of impact that fuel chemistry may have upon this issue has resulted in a need to investigate the cooler fouling process with emerging non-traditional fuel sources to gage their impact on the process. This study reports experiments using both ultra-low sulfur diesel (ULSD) and 20% biodiesel (B20) at elevated exhaust hydrocarbon conditions to investigate the EGR cooler fouling process. The results show that there is little difference between the degradation in cooler effectiveness for ULSD and B20 at identical conditions. At lower coolant temperatures, B20 exhibits elevated organic fractions in the deposits compared with ULSD, but this does not appear to lead to incremental performance degradation under the conditions studied. Comparisons with a previous study conducted at low HC levels shows that the presence of increased volatiles in the deposit does not impact the degradation in effectiveness significantly. Moreover, the effectiveness loss divided by the deposit mass gain for both low- and high-HC conditions seems to indicate that the HC fraction in the deposit does not significantly alter the overall thermal properties of the deposit layer.

Wheat is a candidate crop for the Advanced Life Support (ALS) system, and cereal grains and their products will be included on long-term space missions beyond low earth orbit. While the exact supply scenario has yet to be determined, some type of post-processing of these grains must occur if they are shipped as bulk ingredients or grown on site for use in foods. Understanding the requirements for processing grains in space is essential for incorporating the process into the ALS food system. The ESM metric developed by NASA describes and compares individual system impact on a closed system in terms of a single parameter, mass. The objective of this study was to compare the impact of grain mill type on the ESM of producing yeast and flat breads. Hard red spring wheat berries were ground using a Brabender Quadrumat Jr. or the Kitchen-Aid grain mill attachment (both are proposed post-harvest technologies for the ALS system) to produce white and whole wheat flour, respectively. Yeast bread was made using three methods (hand+oven, bread machine, mixer with dough hook attachment + oven). Flat bread was made using four methods (hand+oven, hand+griddle, mixer+oven, mixer+griddle). Data on all inputs (active time, passive time, mass and volume of ingredients and equipment, power) were measured and used to calculate ESM. Assumptions were based on data in NASA documents. Data were analyzed using PC-SAS with significance at P < 0.05. Grain mill type significantly (P < 0.05) influenced the ESM of making both bread types; and the Brabender Quadrumat Jr. contributed significantly (P < 0.05) more mass than the Kitchen-Aid grain mill to the ESM for producing both types of bread. Results can be used by systems analysts to define energy and volume requirements for the food system and by researchers to select and modify food production scenarios.

Carbon fiber composite use in automobiles and light trucks could dramatically reduce energy use and engineout emissions. However, worldwide capacity of 28,000 tonnes per year of carbon fiber from polyacrylonitrile (PAN) and petroleum pitch could support limited automotive use. Production of high-volume, industrialgrade fiber from renewable and recycled polymers (lignin, recycled plastics, regenerated cellulosics) could meet automotive demand. Profiles of material volumes, carbon content, and melting points indicate several attractive candidates for production melt-spun carbon fiber feedstocks. Effects on the carbon fiber production cycle and its integration into automotive production are discussed.

This paper presents a high-fidelity electro-thermal model of a half-bridge that consists of IGBTs and anti-parallel diodes. The model calculates and estimates the half-bridge voltages, currents, switching and conduction losses considering the operating temperature and current conditions. Moreover, this model is suitable for varying switching frequency operation. The electro-thermal model can be used as an evaluation tool to analyze the performance of control strategies for traction inverter from efficiency, temperature and component stress point of view. In this paper performance of Direct Torque Model Predictive Control (DTMPC) of an Interior Permanent Magnet Synchronous Motor (IPMSM) is evaluated in comparison with Indirect Field Oriented Control (IFOC) with sinusoidal pulse width modulation (PWM). The inverter model and the MPC are both implemented in C-Mex for rapid execution. The MPC algorithm implemented in this research tracks torque reference while using Maximum-Torque-Per-Ampere (MTPA) strategy and minimizing switching losses. Both control systems are able to follow the speed reference. The MPC shows a decrease in losses compared to IFOC when tested with low-speed and high-speed parts of the WLTC profile.

Modern automotive heating, ventilation, and airconditioning (HVAC) systems have multiple and often redundant actuators. Design of a control system that optimally synthesizes multiple control actions while satisfying control set points and system hardwarerelated constraints is necessary to maximize HVAC efficiency. To this end, an optimization approach to control system design is proposed in this paper and demonstrated for a generic air-conditioning (A/C) system. The paper first outlines a nonlinear 12th-order A/C dynamics model based on the moving-boundary method. Then, the A/C control system is defined, which combines feedback controllers commanding the compressor speed and expansion valve opening, and open-loop actions of condenser and blower fans. Next, a three-stage, multi-objective genetic algorithm-based approach of control system optimization is proposed. The first-stage is aimed at finding a rough estimate of all control inputs, which maximizes the A/C system efficiency while satisfying relaxed control set point constraints. In the second stage, the closed-loop controller parameters are optimized for the operating point obtained in the first stage with the aim to provide a favorable trade-off between the control error suppression and control effort. The third stage includes refined optimization of fans open-loop actions to maximize efficiency, where firmer thermal comfort and safety-related constraints are provided by feedback controllers. Finally, the optimization procedure is carried out for multiple control set points to provide control parameter maps, which are aimed to be used in the form of a gain-scheduling algorithm. Analysis of optimization computational efficiency shows that a substantial improvement is achieved with the proposed, comprehensive three-stage approach when compared to using only the first stage one.

The deterioration of automotive diesel oil (ado) in storage has been investigated. The quality of the fuel produced by the refinery was shown to be the major factor determining the amount of chemical degradation which will occur. Ado containing only distillate from the primary distillation unit is a stable fuel. Blending unhydrogenated catalytically cracked or thermally cracked refinery light cycle oil (lco) with the fuel substantially decreased the storage stability. The amount of organic particulate matter formed on storage is dependent upon both the chemical constitution of the lco and the fuel with which it was blended. Chemical additives which are used to reduce soluble gum formation in gasoline were found to be ineffective in ado. Particulate formation in ado was reduced by additives which inhibited acid catalysed processes in the fuel (a).