Search Results

In order to produce high-quality vehicles today, Management must find new approaches to effectively increase focus and follow-up on quality objectives. At the Westmoreland Assembly Plant, we have made structural organization changes, increased employe involvement, and upgraded quality information systems. These changes have been integrated into an existing operation over a period of several years with good results. Details of the new approaches as well as discussions of how the old supports the new are presented.

The purpose of this paper is to outline a management system which integrates proactive thinking and state-of-the-art statistical tools into the culture of an organization. Specifically, this paper defines a system for developing and manufacturing new products. Emphasis is put on product planning with respect to customer driven requirements of quality, reliability, cost and delivery.

This paper will discuss the issues associated with the creation of embedded software for automotive electronic control systems and show how these issues can be addressed using model-based methods to design, test and implement these systems. Model-based methods are already in use for many automotive applications, and there are potentially many more areas where they could be used, especially as the number and complexity of automotive embedded control systems increase. This paper will cite several examples of the successful use of model-based design.

Monte Carlo simulation is a popular tool for reliability assessment because of its robustness and ease of implementation. A major concern with this method is its computational cost; standard Monte Carlo simulation requires quadrupling the number of replications for halving the standard deviation of the estimated failure probability. Efforts to increase efficiency focus on intelligent sampling procedures and methods for efficient calculation of the performance function of a system. This paper proposes a new method to manage cost that views design as a decision among alternatives with uncertain reliabilities. Information from a simulation has value only if it enables the designer to make a better choice among the alternative options. Consequently, the value of information from the simulation is equal to the gain from using this information to improve the decision. A designer can determine the number of replications that are worth performing by using the method.

Importance Sampling is a popular method for reliability assessment. Although it is significantly more efficient than standard Monte Carlo simulation if a suitable sampling distribution is used, in many design problems it is too expensive. The authors have previously proposed a method to manage the computational cost in standard Monte Carlo simulation that views design as a choice among alternatives with uncertain reliabilities. Information from simulation has value only if it helps the designer make a better choice among the alternatives. This paper extends their method to Importance Sampling. First, the designer estimates the prior probability density functions of the reliabilities of the alternative designs and calculates the expected utility of the choice of the best design. Subsequently, the designer estimates the likelihood function of the probability of failure by performing an initial simulation with Importance Sampling.

Quality itself is no longer a differentiator among aerospace manufacturers. High quality is expected and achievable. With enough time and money, any manufacturer can turn around a high-quality product. Around the globe, the focus of manufacturing quality is shifting to a discussion about the cost of quality and how to manage it. The question being asked by manufacturers is no longer how to achieve quality, but how to achieve it within cost and time constraints. The aerospace manufacturer that can achieve quality with the least expense, while producing products the fastest, is the one that will win in today's tough, global market. This paper will describe the “closed-loop” approach to dimensional engineering, utilizing virtual simulations and tolerance analyses, and how such an approach can link cost factors with tolerance adjustments so that users have the data they need to make the most strategic business decisions regarding the balance between quality and cost.

Trucks are becoming home to more and more on-board-computers (OBCs). One key to managing the influx of new technology is to expand the truck’s current network architecture. Another key is to integrate features into a high performance, expandable truck oriented computer. Many new technologies will be reviewed, including USB, MOST, IEEE 1394, Bluetooth, IDB-M, speech recognition and a comparison of optical or copper networking. This session will discuss issues in selecting suitable network topologies, computing architectures, methods of technology integration, and the migration of new computer and communications technology to the truck environment.

This paper seeks to highlight some of the problems related to deregulation of the airline industry as seen by a major European airline. While deregulation hit the U.S. industry fast and hard, the European operators could enjoy a more slowly emerging relaxation of the traditional tight government control. Nevertheless, the increased competition encountered on the European arena the last ten years has called for decisive action and revised strategies in order to survive. On the basis of the U.S. experience and the general trend in Europe particularly, Scandinavian Airlines (SAS) set out to reorganize the structure of the company and adopt new strategies for the future. In order to anticipate the different markets emerging, SAS established clear quality priorities. Thereafter the company specified standards and goals for some defined strategic operational areas.

Studies in a jet passenger airliner to service shorter routes than those of the Boeing 707 evolved the concept of a rear mounted three engine jet, the 727. The development program had many facets, including extensive use of mockups, customer influence on design through liaison, cost control, and a considerable amount of work on the design of the tail and location and number of engines on the craft.

The ALS Element (Program) has established the ALS metric as its means of measuring project performance. Programmatic goals are to drive the metric upward by a factor of 3 by 2014, thereby reducing the cost of keeping people alive in space. To assess the feasibility of achieving the metric goal, the contributions to the metric of ISS life support items as required for a Mars mission have been identified and sorted by size. Options for dramatically reducing the larger contributions have been identified. In this way, significant improvements might be achieved,. Although the implementation of such achievements is not identified through this process, this approach does identify where development effort is needed, and the magnitude of improvement that could be achieved.

The use of statistical management techniques is being rediscovered by American business executives. These techniques, developed in the 1920’s, were introduced to Japanese managers in 1950 by an American statistician, Dr. W. Edwards Deming, and Japanese manufacturers credit Deming for much of their productivity and quality improvement success. The control chart is one of the most powerful statistical tools for control of processes. It provides a method of timely, direct communication with a process and allows an accurate assessment of process stability and capability to meet end product requirements. Businesses currently using control charts report direct productivity/quality improvements.

The National Highway Traffic Safety Administration (NHTSA) has twice mandated air bag warning labels. This paper reviews and analyzes NHTSA's activities in both the 1993 and 1996 rulemaking procedures against the framework of the available human factors engineering (HFE) and warning literature. It utilizes the full record of the rulemaking process including Federal Register notices and docket submissions to identify the analyses and decisions made by the agency in developing these rules. This analysis concludes that in both the 1993 and 1996 rulemaking procedures, NHTSA developed labeling requirements that appropriately addressed the respective injury prevention policies and strategies of those timeframes. In most regards, the agency properly identified and responded to HFE criteria although some methodological improvements could be obtained.

In a previous SAE paper (2001-01-0046), the authors reviewed the National Highway Traffic Safety Administration's (NHTSA) activities in the development of mandatory air bag warnings and analyzed those activities against the framework of the available human factors engineering (HFE) and warning literature. That analysis concluded that in both rulemaking procedures, NHTSA developed labeling requirements that appropriately addressed the respective injury prevention policies and strategies of those respective timeframes. In most regards, the agency properly identified and responded to HFE criteria although some methodological improvement could be obtained. Since the previous paper, the rulemaking process has continued and there have been significant changes to the mandatory air bag warnings. Some of these changes reflect the improvements in advanced air bag technologies.

As of January, 1986, 19 states have approved mandatory safety belt use laws (MUL). Significant controversy has accompanied these legislative activities regarding the safety benefits of MUL versus the imposition of governmental regulation on personal choice. The purpose of this paper is to present a description of operational experiences of MUL in the U.S. Emphasis is placed on quantitative evidence of the effectiveness of MUL and the potential benefit of such laws in the state of Arizona. It is recognized that the public and its legislative representatives must deal with a wide range of issues associated with MUL. However, operational experiences should be considered heavily in the decision-making process. MULs have been effective in increasing safety belt use. However, without enforcement and public education, declining use rates can be expected. Preliminary estimates indicate that significant reductions in fatalities and serious injuries can be attributed to seat belt laws.

Basilar skull fractures comprise a broad category of injuries that have been attributed to a variety of causal mechanisms including mandibular impacts. The objective of this work is to develop an understanding of the biomechanical mechanisms that result in basilar skull fractures when the head is subject to a mandibular impact. In the characterization of the injury mechanism, two experimental studies have been performed. The first study evaluated the tolerance of the mandible subject to midsymphysis loading on the mental protuberance (chin). Five dynamic impacts using a vertical drop track and one quasi-static test in a servo-hydraulic test frame have been performed. Impact surfaces were varied to assess the influence of loading rate. The mean mandibular fracture tolerance among the six tests was 5270 ± 930 N and appears insensitive to loading rate. In each test, clinically relevant mandibular fractures were produced. No basilar skull fractures were observed.

In two experiments, strategic conflict avoidance maneuvers of 32 licensed pilots were analyzed when they flew a series of missions in a low fidelity (Experiment 1) and a high fidelity (Experiment 2) flight simulator, rendering an outside view and a cockpit display of traffic information. On various legs of the mission, aircraft generating traffic conflicts intruded from above, below and at the same altitude as ownship at various azimuth orientations. Pilot maneuvers were categorized in terms of the dimension of maneuver (vertical, lateral, airspeed), and the direction of change within that maneuver. Decision analysis revealed a strong tendency of pilots to use simple one dimensional maneuvers, and of these, to prefer vertical over lateral and airspeed maneuvers. Airspeed maneuvers in particular were avoided.

The requirement of the start of the internal combustion engine (ICE) not only at vehicle standstill is new for full hybrid electric vehicles in comparison to conventional vehicles. However, the customer will not accept any deterioration with respect to dynamics and comfort. ICE-starting-systems and -strategies have to be designed to meet those demands. Within this research, a method was developed which allows a reproducible maneuver-based analysis of ICE-starts. In the first step, a maneuver catalogue including a customer-oriented maneuver program with appropriate analysis criteria was defined. Afterwards, the maneuvers were implemented and verified in a special test bench environment. Based on the method, two sample hybrid vehicles were benchmarked according to the maneuver catalogue. The benchmarking results demonstrate important dependencies between the criteria-based assessment of ICE-starts and the embedded ICE-starting-system and -strategy.

The increasing numbers of hybrid electric and full electric vehicle models currently in the market or in the pipeline of automotive OEMs require creative testing mechanisms to drive down development costs and optimize the efficiency of these vehicles. In this paper, such a testing mechanism that has been successfully implemented at the US Environmental Protection Agency National Vehicle and Fuel Emissions Laboratory (EPA NVFEL) is described. In this testing scheme, the units-under-test consist of a battery pack and its associated battery management system (BMS). The remaining subsystems, components, and environment of the vehicle are virtual and modeled in high fidelity.

Four-wheel drive vehicles have recently become widely used for their enhanced safety in a variety of road conditions on the highway and snowy, wet, and gravel-covered roads. It is well known that four-wheel drive vehicles are superior in maneuverability to two-wheel drive vehicles. We have attempted to explain this superiority by theoretical as well as experimental methods. This paper deals with the theoretical approach in determining the difference in movements between two-wheel and four-wheel drive vehicles during cornering with varying tire-to-road-surface friction coefficients and wheel loads. Experiments were carried out on paved and snowy roads using the two types of vehicles. As a result, it has been verified quantitatively that the four-wheel drive vehicle provides higher stability with greater variations in friction coefficients and wheel loads, though the difference is only marginal under a steady state.

This paper is concerned with an adjustable scale model capable of tracing maneuverability patterns of trailer trains. The transient kinematic paths of a multiple unit carrier of train configuration consisting of ten cargo units provided with conventional two wheel steering, conventional four wheel steering, and modified four wheel steering with a steering ratio and delayed steering action are investigated and discussed.