Liner CCD for a Single Point of Bridge Vertical Displacement of Non-contact Measurement Technology

2009 ◽  
Author(s):  
Xiangwei Wang ◽  
Xuehua Dong
Keyword(s):  
Single Point ◽  
Vertical Displacement ◽  
Measurement Technology ◽  
Contact Measurement

scholarly journals Application of 3D laser scanning technology in engineering field

2021 ◽  
Vol 233 ◽  
pp. 04014
Author(s):  
Chang’an Hu ◽  
Linghui Kong ◽  
Fei Lv
Keyword(s):  
Laser Scanning ◽  
New Technology ◽  
Single Point ◽  
3D Models ◽  
The Body ◽  
Surface Measurement ◽  
Measurement Technology ◽  
3D Laser Scanning ◽  
High Definition ◽  
Contact Measurement

With the continuous progress of computer and laser measurement technology, non-contact measurement based on laser scanning technology has been more and more applied in the industrial production process. Since the 1990s, 3D laser scanning technology used as a new technology has been developed rapidly. The 3D laser scanning technology, also known as High Definition Surveying (HDS), was based on the principle of laser ranging. The technology on the surface of a measured object can record some features of large dense points, including 3d coordinates, reflectance and texture information, so as to rapidly reconstruct 3D models of a measured target and various map data such as the line, the surface and the body. Meanwhile, it is a revolutionary leap that the technology improves the traditional single point measurement to the surface measurement, and realizes the digital reconstruction of the objects. Especially, for some conditions such as contact measurement and complex component detection that cannot be measured, 3D laser scanning technology has a natural advantage in the field of industrial design and measurement .

Method for localisation of sound sources and aggregation to an acoustic centre

2021 ◽  
Vol 263 (6) ◽  
pp. 894-906
Author(s):  
Yannik Weber ◽  
Matthias Behrendt ◽  
Tobias Gohlke ◽  
Albert Albers
Keyword(s):  
Sound Source ◽  
Single Point ◽  
Construction Cost ◽  
Measurement Technology ◽  
Front Part ◽  
Sound Sources ◽  
Preliminary Work ◽  
Product Engineering ◽  
Driving Conditions

Preliminary work by the IPEK - Institute of Product Engineering at KIT has shown that the simulated pass-by measurement for exterior noise homologation of vehicles has relevant optimization potential: the measurement can be carried out in smaller halls and with a smaller measurement setup than required by the norm and thus with less construction cost and effort. A prerequisite for this however is the scaling of the entire setup. For the scaling in turn, the sound sources of the vehicle must be combined to a single point sound source - the acoustic centre. Previous approaches for conventional drives assume a static centre in the front part of the vehicle. For complex drive topologies, e.g. hybrid drives, and unsteady driving conditions, however, this assumption is not valid anymore. Therefore, with the help of an acoustic camera, a method for localizing the dominant sound sources of the vehicle and a software-based application for summarizing them to an acoustic centre were developed. The method is able to take into account stationary, unsteady and sudden events in the calculation of the acoustic centre, which is moved as a result. Using substitute sound sources and two vehicles, the method and the used measurement technology were examined and verified for their applicability.

scholarly journals Power Transmission Tower Monitoring with Hydrostatic Leveling System: Measurement Refinement and Performance Evaluation

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Xingfu Zhang ◽  
Yongyi Zhang ◽  
Lei Zhang ◽  
Guangxin Qiu ◽  
Dehong Wei
Keyword(s):  
Power Transmission ◽  
Vertical Displacement ◽  
Effect Of Temperature ◽  
Measurement Technology ◽  
Transmission Tower ◽  
Processing Scheme ◽  
Accuracy Measurement ◽  
And Performance ◽  
The Impact ◽  
Day By Day

A hydrostatic leveling system (HLS) is an automated high-accuracy measurement technology widely used for vertical displacement monitoring. This paper focuses on evaluating the performance of HLS for monitoring the deformation of a power transmission tower base together with a slope sensor and displacement meter. The monitoring results show that HLS measurements are strongly affected by the environmental temperature. Therefore, to obtain the actual deformation of a monitoring target, the measurements should be further processed to reduce the effect of temperature on the result. To this end, four data processing schemes are proposed, which are based on the frequency of processing (i.e., day by day, monthly, quarterly, or annually). The results demonstrate that the quarterly processing scheme effectively reduces the impact of temperature on deformation measurements and therefore provides the most accurate results among the four schemes considered. Since after correction, the HLS measurements are consistent with the independent monitoring results obtained from the slope sensor and displacement meter, the proposed correction strategy is workable and might be considered for similar monitoring scenarios in future.

scholarly journals Prototype Experimental Investigation of the Failure Mechanism and Crack Propagation of Segment Lining for Staggered Jointed Assembly

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Songyu Cao ◽  
Kun Feng ◽  
Xun Liu ◽  
Mingqing Xiao ◽  
Chuan He ◽  
...  
Keyword(s):  
Single Point ◽  
Failure Process ◽  
Safety Evaluation ◽  
Vertical Displacement ◽  
Railway Tunnel ◽  
Slow Increase ◽  
Prototype Test ◽  
Longitudinal Joint ◽  
Control Section ◽  
Three Stages

In order to ascertain the failure characteristics of a segment structure with distributed mortises and tenons, one should be aware of the rules of key parameters and the development of cracks during the failure process. In this paper, based on the Foguan-Guangcheng Intercity Railway Tunnel Project, a prototype test of the structure of a segment with a staggered joint assembly was performed to study the local mechanical characteristics of the segment lining of the vault. The main conclusions were as follows: (1) The failure process in the test was classified as large eccentric compression failure, and the bearing capacity limit was M = 1993 kN m. (2) The overall displacement distribution of the segment structure was funnel-shaped, and the failure process was divided into three stages, that is, the elastic stage, the elastoplastic stage, and the plastic stage. Thus, it is recommended that the index of the single-point displacement limit of this tunnel be reduced appropriately to be between 1.5 and 1.8%. (3) The change rule of the longitudinal joint opening of the segment can be divided into three stages, that is, slow increase, accelerated increase, and sharp increase. For normal use, the limit of the opening of the longitudinal joint is set at 3 mm. (4) The width of the structural crack and the vertical displacement of the control section can be used as the safety evaluation index of this project. When either a large increase in the width of the crack occurs or the displacement specified above is reached, it can be considered that the structure is about to fail, and immediate protective measures must be taken.

scholarly journals Three-Dimensional Morphology and Size Measurement of High-Temperature Metal Components Based on Machine Vision Technology: A Review

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4680
Author(s):  
Xin Wen ◽  
Jingpeng Wang ◽  
Guangyu Zhang ◽  
Lianqiang Niu
Keyword(s):  
High Temperature ◽  
Machine Vision ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Measurement Technology ◽  
Metal Component ◽  
Contact Measurement ◽  
Size And Morphology ◽  
Close Distance ◽  
Very High

The three-dimensional (3D) size and morphology of high-temperature metal components need to be measured in real time during manufacturing processes, such as forging and rolling. Since the surface temperature of a metal component is very high during the forming and manufacturing process, manually measuring the size of a metal component at a close distance is difficult; hence, a non-contact measurement technology is required to complete the measurement. Recently, machine vision technology has been developed, which is a non-contact measurement technology that only needs to capture multiple images of a measured object to obtain the 3D size and morphology information, and this technology can be used in some extreme conditions. Machine vision technology has been widely used in industrial, agricultural, military and other fields, especially fields involving various high-temperature metal components. This paper provides a comprehensive review of the application of machine vision technology in measuring the 3D size and morphology of high-temperature metal components. Furthermore, according to the principle and method of measuring equipment structures, this review highlights two aspects in detail: laser scanning measurement and multi-view stereo vision technology. Special attention is paid to each method through comparisons and analyses to provide essential technical references for subsequent researchers.

scholarly journals Dynamic Response of Railway Bogie Due to Change in Vertical Primary Suspension Stiffness Parameters

2011 ◽  
Vol 5 (1) ◽  
pp. 19
Author(s):  
Karim H. Ali Abood ◽  
R. A. Khan
Keyword(s):  
Mathematical Model ◽  
Dynamic Response ◽  
Lateral Displacement ◽  
Single Point ◽  
Vertical Displacement ◽  
Roll Angle ◽  
Dynamic Responses ◽  
Model Combination ◽  
Suspension Stiffness ◽  
Yaw Angle

A mathematical model of a railway carriage moving on tangent tracks is constructed by deriving the equations of motion concerning the model in which single-point and two-point wheel-rail contact is considered. The presented railway carriage model comprises of carbody and front and rear simple conventional bogie with two leading and trailing wheelets attached to each bogie. The railway carriage is modeled by 31 degrees of freedom which govern vertical displacement, lateral displacement, roll angle and yaw angle dynamic response of wheelset whereas vertical displacement, lateral displacement, roll angle, pitch angle and yaw angle dynamic response of carbody and each of the two bogies. Linear stiffness and damping parameters of longitudinal, lateral and vertical primary and secondary suspensions are provided to the railway carriage model. Combination of linear Kalker's theory and nonlinear Heuristic model is adopted to calculate the creep forces in which introduced at wheel and rail contact patch area. Computer aided-simulation is constructed to solve the governing differential equations of the mathematical model using Runge-Kutta fourth order method. Principle of limit cycle and phase plane approach is applied to realize the stability and to evaluate the concerning critical hunting velocity at which railway carriage starts to hunt. Numerical simulation model is used to study the dynamic responses of a railway carriage bogie subjected to specific parameters of wheel conicity and primary suspension characteristics. A comparison to study the sensitivity of railway carriage bogie to dynamic responses is also presented at different vertical primary suspension stiffness parameters.

scholarly journals Design and Analysis of High-Accuracy Telecentric Surface Reconstruction System Based on Line Laser

2021 ◽  
Vol 11 (2) ◽  
pp. 488
Author(s):  
Linshen Yao ◽  
Haibo Liu
Keyword(s):  
Computer Vision ◽  
Surface Reconstruction ◽  
High Accuracy ◽  
Measurement Technology ◽  
Single Camera ◽  
One Dimensional ◽  
Contact Measurement ◽  
Laser Plane ◽  
On Line ◽  
Telecentric Lens

Non-contact measurement technology based on triangulation with cameras is extensively applied to the development of computer vision. However, the accuracy of the technology is generally not satisfactory enough. The application of telecentric lenses can significantly improve the accuracy, but the view of telecentric lenses is limited due to their structure. To address these challenges, a telecentric surface reconstruction system is designed for surface detection, which consists of a single camera with a telecentric lens, line laser generator and one-dimensional displacement platform. The designed system can reconstruct the surface with high accuracy. The measured region is expanded with the used of the displacement platform. To achieve high-accuracy surface reconstruction, we propose a method based on a checkerboard to calibrate the designed system, including line laser plane and motor direction of the displacement platform. Based on the calibrated system, the object under the line laser is measured, and the results of lines are assembled to make the final surface reconstruction. The results show that the designed system can reconstruct a region of 20×40 mm2, up to the accuracy of micron order.

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