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In-Process Hole and Fastener Inspection Using a High-Accuracy Laser Sensor

Electroimpact Inc.-Zachary Luker, Erin Stansbury
  • Technical Paper
  • 2020-01-0015
To be published on 2020-03-10 by SAE International in United States
Electroimpact has produced a new in-process inspection system for use on drilling and fastening systems. The system uses a high-accuracy, non-contact, laser system to measure the flushness of installed fasteners. The system is also capable of measuring part normality and providing feedback to the machine for correction. One drawback to many automatic inspection systems is measurement error. Many sources of measurement error exist in a production environment, including drilling chips, lubrication, and fastener head markings. Electroimpact’s latest system can create a visualization of the measured fastener for the operator to interpret. This allows the operator to determine the cause of a failed measurement, thus reducing machine downtime due to false negatives. Electroimpact created a custom C# WPF application that queries the point-cloud data and analyzes the raw data. A custom “circle Hough transform” scoring algorithm is used to find the center of the nosepiece (pressure foot). A best fit plane is calculated from the point cloud data to find the panel surface. This plane is then used to output panel normality in the A and…
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Wire Fed Laser Directed Energy Deposition Additive Manufacturing Process (L-DED-wire)

AMS AM Additive Manufacturing Metals
  • Aerospace Material Specification
  • AMS7010
  • Current
Published 2020-01-14 by SAE International in United States

This specification establishes process controls for the repeatable production of preforms using the wire fed laser directed energy deposition (L-DED-wire) process for additive manufacturing. Preforms are intended to be used to manufacture aerospace parts, but usage is not limited to such applications.

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Influence of Component Proportion on Multi-Component Surrogate Fuel Spray Characteristics under Subcooled and Superheated Conditions

Nissan Motor CO., LTD. 560-2, Okatsukoku, Atsugi-shi, Kanaga-Ryo Uchida, Taisuke Shiraishi
School of Mechanical Engineering, Shanghai Jiao Tong Univers-Shangze Yang, Xuesong Li, Min Xu
  • Technical Paper
  • 2019-01-2250
Published 2019-12-19 by SAE International in United States
Good comprehension of multi-component fuel spray behavior is essential for the improved performance of GDI engines. In this study, the spray characteristics of three distinct multi-component surrogate fuels with various proportions of n-pentane, iso-octane, and n-decane were investigated using multiple diagnostics including macroscopic imaging, planar laser Mie-scattering, and phase doppler interferometry (PDI). These surrogate fuels were used to mimic different distillation characteristics of regular unleaded gasoline with different vaporization behaviors. Test measurements show that under subcooled test conditions, the spray geometry is mainly influenced by dynamic viscosity. On the contrary, under superheated test conditions, spray geometry is controlled by the specific component of fuel which has the highest vapor pressure. A triangular methodology is created to evaluate the influence of component proportion on spray characteristics. A hierarchical model is then developed to illustrate the macroscopic behavior of multi-component fuel spray which explains well the effect of each component's proportion on the overall spray characteristics.
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Effects of ratio and dwell of split injection on fuel spray and mixture formation process under evaporating, non-reacting condition

University of Hiroshima-Jaeheun Kim, Shinichi Kakami, Keiya Nishida, Yoichi Ogata
  • Technical Paper
  • 2019-01-2323
Published 2019-12-19 by SAE International in United States
The effects of split injections of a diesel spray was evaluated in a constant volume chamber under evaporating, non-reacting condition. Laser absorption scattering (LAS) technique was utilized for the mixture concentration measurement, using a diesel surrogate fuel consists of n-tridecane and 2.5% of 1-methylnaphthalene in volume basis. While fixing the total injected fuel mass of 5.0 mg/hole, the effects of split ratio in mass basis and the dwell time (or injection interval) were investigated. Among the split ratios conducted in the current study (3,7, 5:5 and 7:3), the split ratio of 7:3 was the optimum for lean mixture formation regarding the overall distribution of the equivalence ratio at end-of-injection (EOI) timing. The air entrainment wave at the EOI timing of the first injection allowed the fuel at the vicinity of the nozzle to become leaner at a faster rate. It was thought that, the split ratio of 7:3 provided an adequate amount of fuel quantity and vapor penetration to fit into the fuel-lean region formed from the first injection. The increase of the dwell time…
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Vaporization and Turbulence Characteristics of High Pressure Gasoline Sprays Impinging on a Wall

Mazda Motor Corporation-Wu Zhang, Ryosuke Hara, Tatsuya Fujikawa, Masahisa Yamakawa
University of Hiroshima-Tomohiro Watanabe, Yukihiko Ichikawa, Keiya Nishida, Yoichi Ogata
  • Technical Paper
  • 2019-01-2247
Published 2019-12-19 by SAE International in United States
To get a better understanding of the characteristics of the high pressure gasoline sprays impinging on a wall, a fundamental study was conducted in a high-temperature high-pressure constant volume vessel under the simulated engine conditions of in-cylinder pressures, temperatures, and wall temperatures. The injection pressure was varied from 20 to 120 MPa. The spray tip penetration, vapor mass distribution, and vaporization rate were quantitatively measured with the laser absorption-scattering (LAS) technique. The velocity fields of the wall-impinging sprays under vaporizing conditions were measured with the particle image velocimetry (PIV) technique using silicone oil droplets as tracers. The effects of injection pressure and spray/wall interactions on spray characteristics were investigated. The results showed that the increased injection pressure improved penetration, vaporization, and turbulence of the sprays.
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Effect of Injection Amount on Diesel Spray Characteristics of Multi-Hole Nozzle

Fukuoka Institute of Technology-Keisuke Komada
IRS Corporation-Manabu Saito
  • Technical Paper
  • 2019-01-2284
Published 2019-12-19 by SAE International in United States
A laser 2-focus velocimeter(L2F) has been utilized for the measurements of the velocity and size of droplets in diesel fuel sprays injected from a 6-hole nozzle. The fuel was stored once in a common rail and was injected intermittently to the atmosphere by using a solenoid injector. The diameter of the nozzle orifice was 0.165 mm. The injection pressure was 60 MPa. The injector solenoid was driven by the current having a waveform consisted of 3 stages; boot, pull, and hold. The injection amounts were set at 0.8, 2.9, 3.9 and 4.7mg by changing the durations of the pull stage and the hold stage. The L2F measurement was conducted at 10 mm downstream from the nozzle exit. The fluctuation intensity of the droplet velocity was found to be larger under the smaller injection amount. It was clearly shown that the arithmetic mean droplet size under the smaller injection amount was smaller than that under the larger injection amount during the hold current duration. There was a negative correlation between the droplet size and the droplet…
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Development of a Measuring System for the Visualization of the Oil Film between the Piston and Cylinder Liner of a Gasoline Engine

SAE International Journal of Engines

Technical University of Munich, Germany-Julian Schäffer, Claus Kirner, Martin Härtl, Georg Wachtmeister
  • Journal Article
  • 03-13-02-0013
Published 2019-11-14 by SAE International in United States
The design of cylinder liners, pistons, and piston rings is subject to different conflicting goals. In addition to a loss-free seal of the combustion chamber, sufficient oil must be present between the friction partners. Both the reduction of piston assembly friction and the minimization of oil consumption are crucial to achieve the strictly defined CO2 and emission standards. To master this challenge and find the best compromise requires a lot of system-specific know-how. The automobile and engine manufacturers focus mainly on friction-reducing measures, which are analyzed with different measuring methods such as the floating-liner method, the strip-down method, or the instantaneous indicated mean effective pressure (IMEP) method. However, the interpretation of the results and the development of realistic simulation models lacks information about the oil film behavior and the film thickness. In order to gain this missing knowledge, instruments for oil film visualization and oil film thickness measurement have to be developed. In this study, the two-dimensional laser-induced fluorescence method (2D-LIF) is used to visualize the lubricating oil film between the piston and the cylinder…
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Towards High Accuracy Parking Slot Detection for Automated Valet Parking System

Tongji University-Qinghua Yang, Hui Chen, Junzhe Su, Jie Li
Published 2019-11-04 by SAE International in United States
Highly accurate parking slot detection methods are crucial for Automated Valet Parking (AVP) systems, to meet their demanding safety and functional requirements. While previous efforts have mostly focused on the algorithms’ capabilities to detect different types of slots under varying conditions, i.e. the detection rate, their accuracy has received little attention at this time. This paper highlights the importance of trustworthy slot detection methods, which address both the detection rate and the detection accuracy. To achieve this goal, an accurate slot detection method and a reliable ground-truth slot measurement method have been proposed in this paper. First, based on a 2D laser range finder, datapoints of obstacle vehicles on both sides of a slot have been collected and preprocessed. Second, the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm has been improved to efficiently cluster these unevenly-distributed datapoints. After that, the Random Sample Consensus (RANSAC) algorithm has been improved to accurately fit the vehicles’ longitudinal contours. Finally, the candidate slot has been constructed and checked for its rationality. The final slot detection results have…
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Using Simulation to Evaluate Laser Treatment Methods for Eye Tumors

  • Magazine Article
  • TBMG-35496
Published 2019-11-01 by Tech Briefs Media Group in United States

Computational methods are not widely used in practical medicine, mainly because it is difficult to model specific medical procedures and their effects on the human organism and methods of treatment tend to be conservative. However, new methods to treat cancer using radiology and laser radiation are emerging at a rapid rate.

Bringing Precision Anamorphic Micro-Optics to Consumer-Level Laser Applications

  • Magazine Article
  • TBMG-35475
Published 2019-11-01 by Tech Briefs Media Group in United States

The use of laser light for precise illumination has been limited to high-end applications like optical lithography or small niche markets like measurement technologies. Now that such industries as automotive and consumer electronics are developing and ramping up the production of LIDAR and 3D sensors, laser illumination is scaling in a new direction. For imaging applications, optics made of polymers are already the first choice for such devices as smart cameras. But in order to deliver glass micro-optics with better performance and long-term stability, the cost structure of injection molded polymer optics needed to be addressed.