To improve the performance and reduce weight of new-generation transparent windshields in aircraft, composite structures are commonly used. The thickness each layer a windshield has significant impact on its optical properties load-bearing capacity. However, existing measurement methods for either cannot meet requirements terms range efficiency, or measure windshield. In this paper, large-range spectral-domain low-coherence method is proposed. Specifically, two-dimensional dispersion...

In level set method, initialization mode not only influences evidently the implementation efficiency but also relates directly to final results. The paper presents an new scheme for improving segmentation performance of Chan-Vese model. proposed consists two stages. first stage computes rough edges by using canny edge detection operator. second removes noise and redundant a morphological filter, generates closed contours iteratively connecting points according local cost function. comparison...

Airport runway recognition technology would play an important role in developing intelligent weapon systems the future. In this letter, a method of automatically finding runways forward looking infrared (FLIR) images is proposed based on knowledge vision. First, line segments are extracted by fast segment detector (LSD) and improved linking method. Then, regions interest (ROI) detected using some constraint rules direction, gradient, width pairs. Afterward, ROI length backtracking technique...

This paper presents a new feature matching algorithm for nonrigid multimodal image registration. The proposed first constructs phase congruency representations (PCR) of images to be registered. Then scale invariant transform (SIFT) method is applied capture significant points from PCR. Subsequently, the putative obtained by nearest neighbour in SIFT descriptor space. then integrated into Coherent Point Drift (CPD) so that appropriate two point sets solved combining appearance with distance...

This paper focuses on developing an algorithm that can generate toolpaths in NURBS form for smooth, high speed and accurate machining. The initial are obtained by tool radius compensation method which is based the workpiece boundary offsetting. According to different lengths continuous short block (CSB) criterion, these offset linear segments be regarded as CSBs or long straight segments. Junctions located where curvature value greater than preset threshold it changes abruptly, at two end...

High-precision measurement of sizes and key parameters industrial parts is crucial to ensure manufacturing accuracy assembly reliability. Low coherence methods, offer advantages including high-precision, relatively large measuring range, nondestructive nature. These methods have shown great potential for applications in the field measurement. However, most current low assume that surface reflectance constant or has little variability, resulting poor adaptability limited application range...

The measurement accuracy of a phase-shifting system is adversely affected by phase errors. This paper presents theoretical analysis errors caused nonuniform surface reflectivity, such as varying reflectivity and sharp change in reflectivity. Based on the analysis, method to adaptively adjust maximum input gray level each pixel projected fringe patterns local was proposed reduce Experimental results for planar checkerboard show that error can be reduced 56.6% using method.

Abstract 3D scanning is a crucial step to ensuring the machining quality of workpiece and an essential part intelligent manufacturing. However, existing systems usually have only one profiler, which must be combined with dynamic tracking system achieve complete scan workpiece. This method has low efficiency complicated path planning for ring-shaped workpieces. Therefore, in this article, efficient high-accuracy composed linear translation stage four uniformly distributed laser profilers...

Multi-camera systems have important applications in industrial online measurement, attracting wide interest due to their encouraging performance. However, how develop a convenient and high-accuracy multi-camera calibration model is big challenge. Traditional methods based on 2D object require the preparation of high-precision large-scale object, poor adaptability spatial distribution cameras. To address these issues, accurate method proposed imperfect spherical object. Specifically, special...

In this paper, we proposed an improved version of the Marching Cube algorithm which gives topologically correct triangular approximation isosurface for any cube configuration. First, classification and characterization critical points on trilinear functions is studied in detail. Then, unlike past work algorithm, a robust triangulation strategy without using conventional look-up table complementary rotation operations presented. Our adaptive to small changes data or threshold, obtains more...

The initialization is an important step in the level set method. However, it a computational time-consuming step. In order to speed up evolution procedures, we first introduce new algorithm based on vector distance transform, which propagates with position of nearest object pixel instead scalar distance. A sign map labeling method, flood fill, proposed distinguish inside and outside 2D closed active contour. contour model by Chan Vese (Chan Vese, 2001) can detect whose boundaries are not...

In this paper, we propose a new robust algorithm for the detection of maximum inscribed circles (MIC) in images. We first use vector distance transformation (VDT) strategy to create field. Then, globally search maximal value field extract medial axes. Finally, give procedure determine center and radius MIC. Our experimental results show indeed that is capable detecting MIC with excellent accuracy high efficiency under various image conditions.

Due to the problem that camera model is only effective for a fixed depth of field view because lacking information traditional model, we propose an improved based on in binocular visual system. This depth-based improves stability camera's measurement accuracy when changes.

Abstract Control point detection in industrial pipelines, characterized by flanges and multiple passes, is critical for accurate virtual simulations quality assessments manufacturing. This paper introduces an innovative method detecting control points complex pipelines using incomplete clouds, significantly streamlining the process. Our approach uniquely requires only straight sections end-plane localizations as inputs, markedly reducing both data acquisition processing times. We develop a...

Camera calibration is one of critical steps in computer vision, also an exhaustive process because substantial human interactions are frequently required to deal with the matching problem. In this paper, automatic method markers for camera presented based on local architecture characteristics a new planar circle pattern, which can be applied wide range spoiled images including those distortion, noise, and blur. Firstly, robust ellipse detector developed extract ellipses from image. After...

This paper introduces some key technologies in laser path generation including contour scanning and internal for stereolithography. To generate the cross-sectional contours must be offset a distance inward solid area course of machining parts because size light spot. A simple calculating method modified algorithm detecting self-intersection points are presented. an sub-regional is The divides complex sectional into non-hole sub-region, every sub-region continuous sub-regions scanned turn. At...

Rapid prototyping is a technology of layered manufacturing; therefore, the scanning path certain layer quite important. An algorithm sub-regional generation presented in paper. The divides complex sectional contours into some simple non-hole sub-region, every sub-region continuous and sub-regions are scanned turn. At same while, optimized two ways. first one that joining between regions optimized, which effective on decreasing vacant path. second out place at extreme points optimized....

The accuracy of binocular visual system calibration using the traditional method is poor in depth direction. To enlarge high-accuracy field view (FOV) a system, 3D spatial distortion model (3DSDM) based on Lagrange difference proposed to minimize space distortion. In addition, global (GBVM) that contains 3DSDM and system. GBVM reconstruction are Levenberg-Marquardt method. Experiments were carried out verify our by measuring length gauge space. show compared methods can improve Our has lower...