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Technical Paper

3D Countersink Measurement

Accurate measurement of countersinks in curved parts has always been a challenge. The countersink reference is defined relative to the panel surface which includes some degree of curvature. This curvature thus makes accurate measurements very difficult using both contact and 2D non-contact measurements. By utilizing structured light 3D vision technologies, the ability to very accurately measure a countersink to small tolerances can be achieved. By knowing the pose of the camera and projector, triangulation can be used to calculate the distance to thousands of points on the panel and countersink surface. The plane of the panel is then calculated using Random Sample Consensus (RANSAC) method from the dataset of points which can be adjusted to account for panel curvatures. The countersink is then found using a similar RANSAC method.
Technical Paper

3D Image Metrology for Lean Manufacturing

The need to improve quality while reducing cost in aerospace manufacturing is requiring new manufacturing methods and processes. Advanced technologies, such as 3D Image Metrology, offer great potential to lean manufacturing, if properly integrated into the production process. Over the last years 3D Image Metrology has developed a level of performance, which make it ideally suited for this purpose. These capabilities include the automatic in-process inspection of tools and parts before machining, machine control for highly accurate positioning during the machining operation, and in-process inspection during machining. This offers jig-less assembly, lower inventory, faster part throughput, and many more advantages.
Technical Paper

A Bus Fleet - Maintenance Routines and Controls

A broad look at the Cleveland Transit System inspection program is given, showing the types of inspections performed and the forms that are used with those inspections. The major reports and records of the system are also covered and their use by several echelons of management described. Of special interest is the method used in collecting mileage.
Technical Paper

A CFD Approach via Large Eddy Simulation to the Flow Field with Complex Geometrical Configurations: A Study Case of Vehicle Underbody Flows

CFD is becoming an inevitable modern engineering tool in the vehicle aerodynamics. A LES based CFD approach is proposed for analysis for flows with complex geometrical configurations to which detailed experiments, high grid-density LES or DNS cannot be applicable. How CFD results should be evaluated for cases in which the related experiments are not available. The procedure proposed consists of four stages, i.e., inspections of solutions with coarse and fine meshes, reconfirmation of energy spectrum, references to the similar experiments, explanations of results obtained. The procedures are applied to the underbody flows with a semi-complex underbody configuration.
Technical Paper

A Comparison of Fourier Transform Infrared Spectroscopy with Traditional Analyzers for Enhanced Inspection and Maintenance Testing

The IM240[1] inspection and maintenance test is being implemented in a number of cities throughout the country. This test, which requires the vehicle to be run on a chassis dynamometer, is designed to detect excessive exhaust emissions during different types of driving conditions. The present IM240 test procedure requires the use of four separate analyzers to provide modal information for CO, NOx, CO2 and total hydrocarbon from “in-use” vehicles. There are significant concerns about the calibration and complexity of this instrumentation for the level of use that is expected. A single FT-IR analyzer is capable of rapidly measuring the concentrations of many of the species found in tailpipe emissions. In this paper we will describe the results of a series of evaluation tests that we performed to compare the precision and accuracy of an FT-IR analyzer with the four analyzers presently used for the IM240 test.
Technical Paper

A Comparison of Private Garage and Centralized I&M Programs

A fundamental decision to be made in developing a motor vehicle Inspection and Maintenance (I&M) program is whether a “centralized” or “private garage” program will be used. Under the centralized approach, the state or a state contractor operates a network of single purpose “Inspection Centers” to inspect motor vehicles before the completion of the annual registration renewal process. After any repairs necessary to correct vehicles with excessive emissions are made at a facility of the owner's choosing, the vehicle must pass a reinspection at the Inspection Center. Under the private garage (decentralized) approach, both inspections and repairs are conducted by private repair facilities licensed by the state. A comparison of a centralized I&M program and a private garage I&M program currently operating in California indicates that the centralized program is providing over ten times greater emissions reductions.
Technical Paper

A Correlation of the TEMPERATURE-V/L CHARACTERISTICS of Motor Gasolines with Inspection Test Data

THE results of an investigation of the vapor-forming characteristics of gasoline are here presented in the form of a correlation whereby vapor-forming characteristics can be estimated from the customary gasoline inspection test data. These results are applicable in considering vapor-lock test data when it is important to know the vapor-forming characteristics of the gasolines employed in the test and, in particular, when it is necessary to apply vapor-lock test results to fuels other than those directly employed in testing.
Technical Paper

A Faster Hole Inspection System for Automated Drilling and Fastening Equipment

An automated drilling and fastening system is under development at the GEMCOR Engineering Corporation for wing manufacture on a new commercial airframe program. It is the first time that cold-working and hole inspection have been integrated into an automated fastener installation system. Numerical control and monitoring of all process parameters have been integrated in the system to achieve the greatest degree of accuracy and repeatability in fastener installation and to provide real-time, in-process statistical quality control. An integral component of the system is a capacitance probe used to measure the diameter and profile of drilled holes. Measurement information obtained with the hole probe is used to monitor the drilling process and predict tooling wear. This paper briefly discusses fastener hole requirements and the effects of hole quality on fatigue life. An overview of the capacitance measurement technique is also presented.
Technical Paper

A Five-Point Program Designed to Eliminate Contamination and Corrosion of Fuel Tanks on Aircraft Using Jet Turbine Fuel

A general discussion of the problems resulting from the introduction of contaminated jet turbine fuel into integral fuel tanks and a five-point program designed to eliminate the contamination problem are presented. Some areas covered are: inspection of fuel sources for contamination to prevent contaminants from entering the aircraft fuel system; decontamination of fuel sources; inspection and decontamination of the aircraft fuel system; use of additives for the control of microorganisms; materials and methods, including a simple system for introducing the additives. The good and bad points of all fuel tank sealing and finishing systems presently in use are discussed, and a new finish system completely resistant to degradation by microorganisms is introduced. Simple means of controlling fuel quality entering the aircraft from uncontrolled sources are outlined.
Technical Paper

A Framework of DFSS Application in Flexible Inspection System (FIS)

Design for Six Sigma (DFSS) is a product improvement process based on statistical problem solving capabilities which is typically followed IDDOV approach - Identify, Define, Develop, Optimize, and Verify the design. Flexible inspection system (FIS) is defined as one where the inspection routines are not fixed but are determined just prior to performing the inspection [1]. In FIS the inspection stations have the capacity of performing different inspection routines according to a global inspection strategy. In this paper, the IDDOV steps, as well as some DFSS variation analysis techniques, are applied with the FIS to provide an analytical framework for an optimized strategy of real time inspection allocations.
Technical Paper

A General Aviation Operator Views His Equipment

Each new model change usually brings improvements over earlier models. From the point of view of increasing window area and designing more pleasing appointments, there have been significant advances. With regard to engine reliability and time between overhauls, significant advances have also been made. Solutions to some of the other problems, however, have made little gains. Examples are pilot sitting position and ease of seeing outside the cockpit area; noise level for effective verbal communications between instructor and student; and shoulder space for instructor and student in trainers. An area where major strides are yet to be made is in panel, cockpit, instrument, and control layout and function. A continuing concern expressed by pilots is the transition time from one aircraft to another or the problems of regularly operating in two or more aircraft. This suggests that there is a need to provide more commonality between airplane layouts.
Journal Article

A Heuristic Approach for Offboard-Diagnostics in Advanced Automotive Systems

As the complexity of current automobiles increases, new and innovative diagnostic methods for car maintenance and diagnostic inspection are greatly needed. This paper introduces a new diagnostic approach, which learns from previous repair cases with the help of neural networks in order to assist future diagnostic inspections. Practical experiments have shown that this approach is able to provide promising results even with the data that is already available today.
Technical Paper

A Knowledge Representation Scheme for Nondestructive Testing of Composite Components

This paper presents our efforts to formalize the knowledge domain of nondestructive quality control of automotive composite components with organic (resin) matrices and to develop a prototype knowledge-based system, called NICC for Nondestructive Inspection of Composite Components, to help in the quality assurance of individual components. Geometric and bonding characteristics of parts and assemblies are taken into account, as opposed to the better understood evaluation of test specimens. The reasoning process was divided in two stages: in the first stage all flaws that might be present in the given part are characterized; in the second stage appropriate nondestructive testing procedures are specified to detect each of the possible flaws. The use of nondestructive techniques in the inspection of composites is fairly recent and hence, the knowledge required to develop an expert system is still very scattered and not fully covered in the literature.
Technical Paper


The Standard Oil Development Company has developed a new test for evaluating the sludge handling ability of lubricants. Oil Sludging Test measures the sludge handling ability of lubricants in terms of the time required to reach 50% oil screen plugging in cyclic laboratory engine operation. The manner in which sludge builds up in this test is similar to the way it builds up in field engines. Results correlate very well with those obtained in low temperature, stop-and-go field service. The test conditions were chosen after studying the conditions found to be conducive to sludge formation in the field. A six cylinder, overhead valve engine is modified by enlarging the piston ring gaps to increase blow-by. It is then run in 4 hour cycles. Each cycle includes 1-1/2 hours of idle with 115°F. oil temperature and 2 hours of loaded operation with 180°F. oil temperature. This is followed by a 1/2 hour shutdown under cold conditions.
Technical Paper

A Neuro-Fuzzy Approach to a Machine Vision-based Parts Inspection Problem

This paper describes a research project whose objective is to improve the parts inspection component of the automotive manufacturing process through the application of neuro-fuzzy systems. The basic methodology is to circulate case studies of industrial inspection problems among 5 universities and challenge the researchers to find more robust analysis algorithms. This paper presents initial work on one of the case studies whose subject is the application of a machine vision-based system to identify missing fasteners in a cross-car beam.
Technical Paper

A Nondestructive Inspection System for the Inspection of Wear Surfaces in Tank Track Shoes

In this paper we present a unique nondestructive inspection (NDI) system for inspection of al/sic metal matrix composite (MMC) inserts in cast aluminum tank track shoes (TTS). The system is based on two different nondestructive inspection methods, ultrasonics (UT) and eddy current (EC), which are capable of detecting and identifying defects in MMC, such as porosity, debonding, and cracking. This paper also discusses results obtained during inspections of Al/SiC MMC samples with different levels of porosity, and debonds using UT and EC inspection. The prototype version of the system is designed to perform an acceptance inspection after TTS manufacturing and before deployment. Other potential applications of this system are in the evaluation of complex MMC parts in the automotive industry.
Technical Paper

A Novel Couplant Free Mediator Ultrasonic Rayleigh Wave Technique for Detecting Surface Cracks in Green Parts

Surface cracks initiated by handling and production issues in green parts affect the final integrity of a sintered part. The subject of crack detection in green parts has been of significant interest for decades with no real solution being available until recently. Despite the abundance of applicable techniques for inspecting sintered parts, green part inspection techniques are restricted. Some promise has been recently demonstrated with visual and resonance techniques; however the success of these methods is limited. Presented here is a novel surface wave approach based on the use of a couplant free mediator. Surface wave techniques are presented as an economical and reliable alternative to current nondestructive inspection methods. Design of a test setup for analyzing the applicability of surface wave techniques to detect cracks in specific orientations in green parts is provided.
Technical Paper

A Portable Hybrid Ultrasound-Eddy Current NDI System for Metal Matrix Composite Track Shoes

Track shoes made of Metal Matrix Composite (MMC) are light in weight, and can resist high temperature and wear. Defects such as disbond, cracks and porosity can be introduced during the manufacturing process and while in service. Presented in this paper is a portable nondestructive inspection (NDI) system to automatically inspect the tank track shoes for disbond, cracks and porosity defects. The work focuses on the inspection of the track shoe center spline where MMC inserts are attached to the aluminum substrate. A hybrid approach has been developed where an array of broadband high frequency ultrasonic transducers operating in a pulse/echo mode are utilized to detect disbond, and a scanning eddy current probe array is used to detect cracks and porosity. The Inspection results agree quite well with immersion ultrasonic C-scan images and destructive tests.
Technical Paper

A Practical Approach to the Reduction of Vehicular Carbon Monoxide Fatalities

The cause of accidental carbon monoxide (CO) poisonings often involves an interaction of poor vehicular design, flimsy vehicular construction, poor vehicular maintenance, faulty repair work, and careless use of the vehicle. An approach to the reduction of these accidents must therefore concentrate on practical ways to prevent, detect, and eliminate vehicular defects leading to the introduction of exhaust gases into passenger compartments. Examples of such methods include redesign of exhaust systems, implementation of sturdier construction materials, more comprehensive motor vehicle inspection systems, and the education of vehicle owners and vehicle repairmen on the prevention and detection of defects in vehicular exhaust systems and components of vehicle bodies adjacent to the exhaust system. Case studies are presented representing common modes of CO poisoning in vehicular settings, and for each case a cause is determined and discussed in terms of preventive action needed.
Technical Paper

A Prototype Computer Based Test System to Test Commercial Vehicle Air Brake Systems: Application and Test Results

This paper describes a practical and efficient approach for determining complete transient, as well as steady state response of tractor-trailer air brake systems by recording pushrod displacement and air brake service line pressure as a function to time. The test hardware utilizes easy to fabricate “clip on” transducers to measure pushrod stroke length. Data acquisition is via LABVIEW‚. All transducers are easy to temporarily affix to any tractor- trailer and require no alteration to the vehicle. A complete system check takes less time than manually measuring pushrod stroke as required under FMCSA. This system with one treadle application and release gives digital timing and displacement history of all brakes. Useful information includes: application and release profiles (pushrod velocity), shoe compliance upon seating and crack pressure release points for both tractor and trailer relay valves.