Optical Design for Laser Diode Scanner Headlamp with Efficiently Distributed Optical Power for Adaptive Driving Beam System of Automobiles

The illumination optical system using a laser diode has advantages such as small size and high efficiency compared to an optical system using a conventional light source. In particular, its advantages can be maximized in high-resolution spatial light modulation. Based on these advantages, research to apply laser diode scanning to high-resolution adaptive driving beam (ADB) is currently being actively conducted. To construct a high-resolution illumination optical system for an ADB system using a single laser diode as a light source, the configuration of an optical scanning system is essential. In the general high-speed scanning method, the optical power at the center is relatively smaller compared with that at the edge because of the faster scanning speed when the center is illuminated. This causes large losses in automotive lighting optical system where the optical power in the center should be higher. Herein, we propose an optical system that can change the light power distribution of the center and the edge by applying a prism. In addition, by producing a prototype of an optical scanning system, the effect of efficiently distributing optical power by the designed optical scanning system was experimentally verified.

Vehicle Image Classifier for Bridge Displacement Correlation

Advanced computing brings opportunities for innovation in a broad gamma of applications. Traditional practices based on visual and manual methods tend to be replaced by cyber-physical systems to automate processes. The present work introduces an example of this, a machine vision system research based on deep learning to classify bridge load, to give support to an optical scanning system for structural health monitoring tasks. The optical scanning system monitors the health of structures, such as buildings, warehouses, water dams, etc. by the measurement of their coordinates to identify if a coordinate displacement befalls that could indicate an anomaly in the structure that can be related to structural damage. The use of this optical scanning system to monitor the structural health of bridges is a little more complicated due to the vehicle's transit over the bridge that causes a vehicle-bridge interaction which manifests as a bridge oscillation. Under this scheme, the bridge oscillation corresponds to their coordinate’s displacement due to the vehicle-bridge interaction, but not necessarily due to bridge damage. So, a bridge load classifier is required to correlate the bridge coordinates measurements behavior with the bridge oscillation due to vehicle-bridge interaction to discriminate the normal behavior of the structure to abnormal behavior or identify tendencies that could indicate bridge deformation or discover if the bridge behavior due to loads is changing through the time.

Accuracy of High Resolution 3D Optical Scanning of Crosstie Geometry for Assessment of Cross-Sectional Parameters and Long-Term Abrasion and Wear

Current research is attempting to develop a comprehensive understanding of the material and manufacturing characteristics that have caused splitting failures in prestressed concrete railroad ties, in contrast with those characteristics that have resulted in ties that have performed well after many years in track. As part of this effort, a three-dimensional (3D) Optical Scanning System is being used to accurately scan and quantify the surface geometry and volume (abrasion and wear) of a large sample of previously manufactured ties. A commercially-available 3D Laser-Based Optical Scanning System, having a maximum spatial resolution of approximately 0.1mm, is being used to perform the surface scanning operation. The scanning procedure ideally produces an accurate 3D CAD model of the tie geometry, which can then be analyzed to determine the desired geometrical features at any given cross-section. It can likewise yield a measure of the tie volume, the variation of which gives some direct indication of the extent of abrasion and wear. The feasibility of the scanning system has previously been demonstrated by extracting the detailed longitudinal variation of geometrical cross-section crosstie parameters of a typical CXT tie, including cross-sectional area, centroid, moment of inertia, and the eccentricity of the prestressing wires. These parameters are also known to be of importance to the accurate determination of transfer length from measured surface strain. The CXT tie geometry provides an excellent test case, and a challenge to the optical scanning system, since it has a complex scalloping along its length. While the basic feasibility of the system operation has been demonstrated, the repeatability of the geometrical information obtained from the overall scanning and subsequent post-processing of surface geometrical data has yet to be assessed. The main objective of this paper is to first demonstrate the volumetric measurement resolution experimentally by conducting repeated scans of the same tie by the same operator. The experimental scatter in scan results is presented for both cross-section parameter detail and tie volume assessment. The statistical variation in the measured tie volume ideally provides a reasonable measure of the expected volume resolution. In addition to assessing the statistics of these repeated scans, a CXT tie was subjected to induced abrasions of known (measurable) volume for direct comparison with the volume measurements obtained using the optical scanning procedure. This work represents an important next step toward identifying the accuracy of the assessment of abrasion and wear for the large number of ties currently being scanned after having been in long-term service.