An Analysis Model for Structural Optimization of Polygon Ranging-Based Space Coordinate Measurement Network

2012 ◽  
Vol 239-240 ◽  
pp. 760-768
Author(s):  
Jia Wen Hu ◽  
Xiao Fen Yu ◽  
Jun Tong Miu ◽  
Ming Zhu
Keyword(s):  
Structural Optimization ◽  
Large Scale ◽  
Measurement Accuracy ◽  
Structural Parameters ◽  
Base Stations ◽  
Analysis Model ◽  
Coordinate Measurement ◽  
Local Accuracy ◽  
High Measurement ◽  
Space Coordinate

Polygon ranging-based space coordinate measurement network, which has high measurement accuracy and simple structure, is suitable for large-scale metrology. In practice, the measurement network should be constructed flexibly according to coverage and shape and measurement accuracy of different measurand. Based on this, a universal analysis model of structural optimization is proposed. The relation between structural parameters (amount and layout of measurement base stations) and distribution of measurement accuracy of the measurement network are researched on the model. The model can provide theoretic basis for optimized and flexible design of the measurement network. A case is used to illustrate this model. The results verify that the module can be used for scientifically establishing measurement system of ultra-large size, and also preliminarily simulating and optimally designing the being adopted measurement network and measurement method for meeting requirements of size and measurement accuracy (including global and local accuracy) of different work pieces.

scholarly journals Structural optimization considering the probabilistic system response

2004 ◽  
Vol 31 (3-4) ◽  
pp. 361-394 ◽  
Author(s):  
M. Papadrakakis ◽  
N.D. Lagaros ◽  
V. Plevris
Keyword(s):  
Structural Optimization ◽  
Design Optimization ◽  
Robust Design ◽  
Large Scale ◽  
Optimization Problem ◽  
Structural Parameters ◽  
Dominant Role ◽  
Robust Design Optimization ◽  
Design Parameters ◽  
System Response

In engineering problems, the randomness and uncertainties are inherent and the scatter of structural parameters from their nominal ideal values is unavoidable. In Reliability Based Design Optimization (RBDO) and Robust Design Optimization (RDO) the uncertainties play a dominant role in the formulation of the structural optimization problem. In an RBDO problem additional non deterministic constraint functions are considered while an RDO formulation leads to designs with a state of robustness, so that their performance is the least sensitive to the variability of the uncertain variables. In the first part of this study a metamodel assisted RBDO methodology is examined for large scale structural systems. In the second part an RDO structural problem is considered. The task of robust design optimization of structures is formulated as a multi-criteria optimization problem, in which the design variables of the optimization problem, together with other design parameters such as the modulus of elasticity and the yield stress are considered as random variables with a mean value equal to their nominal value. .

Research on Measure Method of Common Normal Length Variation of Bilateral Modification Gear

2012 ◽  
Vol 569 ◽  
pp. 568-571
Author(s):  
Yu Lan Wei ◽  
Qi Bo Yan ◽  
Bing Li ◽  
Hao Xu ◽  
Ying Ying Fan
Keyword(s):  
Measurement Accuracy ◽  
Length Variation ◽  
Human Intervention ◽  
Normal Length ◽  
Coordinate Measurement ◽  
Coordinate Measurement Machine ◽  
High Measurement ◽  
Tooth Number ◽  
The Common ◽  
High Measurement Accuracy

In the conditions of rationally selecting of the measure tooth number, this paper puts forward a new method to calculate the common normal length variation, which is based on coordinate measurement machine to collect the data of bilateral modification gear's outline. Firstly, the addendum modification coefficient and tangential modification coefficient are used to determine the optimum measure tooth number, and then the common normal length variation is determined according to the definition. The experiment has shown that this way has a lot of advantages, such as the intensive data of sample points, less human intervention and high measurement accuracy.

scholarly journals Method of improving large-scale measurement accuracy of laser tracker based on photogrammetry

2019 ◽  
Vol 52 (9-10) ◽  
pp. 1220-1227 ◽  
Author(s):  
Chengyang Zhang ◽  
Xishuang Jing ◽  
Siyu Chen ◽  
Xuanzhe Ling ◽  
Jiarong Zou ◽  
...  
Keyword(s):  
Large Scale ◽  
Measurement Accuracy ◽  
Measurement Data ◽  
Correction Method ◽  
Laser Tracker ◽  
Digital Measurement ◽  
Long Distance ◽  
Measurement Results ◽  
High Measurement ◽  
Coordinate Correction

Background: When performing the spatial large-scale measurements, the measurement accuracy of laser tracker would decreased with the increase of the measurement distances due to the refraction difference of most optical digital measurement devices. Therefore, this paper proposed a method based on photogrammetry system to improve the large-scale measurement accuracy of the laser tracker. Purpose: The purpose of this method is to improve the large-scale measurement accuracy of the laser tracker by considering the advantages of photogrammetry system such as high measurement accuracy and good portability. Methods: The measurement data from the photogrammetry system would be used as a reference to do correction on measurement results from laser tracker. The coordinate correction method based on Rodrigues’ rotation formula has been discussed. The measurement accuracy of the long-distance point of laser tracker can be significantly improved through the coordinate correction method. Conclusion: Based on the advantages of using photogrammetry system, the proposed method can achieve higher accuracy when measuring the common points at a closer distance than the laser tracker can do when measuring objects far away from instrument. The feasibility of the proposed method has been demonstrated by experiment.

Measurement of Spacecraft Simulator Motion Parameters Based on Multi-Vision System

2012 ◽  
Vol 605-607 ◽  
pp. 1080-1084
Author(s):  
Yu Bo Guo ◽  
Hui Ping Ma ◽  
Qi Xia ◽  
Gang Chen ◽  
Feng Yuan
Keyword(s):  
Measurement Accuracy ◽  
Large Range ◽  
Vision System ◽  
Time Measurement ◽  
Coordinate Measurement ◽  
Real Time Measurement ◽  
High Measurement ◽  
Motion Parameters ◽  
Simulator Motion ◽  
Rotation Motion

A real-time measurement method based on multi-vision system is presented for measuring the motion parameters of three-DOF spacecraft simulator. Four cameras are arranged around the motion space of the simulator. When the simulator makes large range translation and rotation motion, 3D coordinate measurement can be realized for any marker provided that such marker is identified by 2 or more cameras. And the motion parameters of simulator can be measured when more than 3 markers are identified in each measurement. The experiment results verify this method and show it can achieve high measurement accuracy.

scholarly journals Comparative Analysis of the Life-Cycle Cost of Robot Substitution: A Case of Automobile Welding Production in China

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 226
Author(s):  
Xuyang Zhao ◽  
Cisheng Wu ◽  
Duanyong Liu
Keyword(s):  
Life Cycle ◽  
Systems Engineering ◽  
Life Cycle Cost ◽  
Manufacturing Systems ◽  
Large Scale ◽  
Cost Allocation ◽  
Industrial Robot ◽  
Case Analysis ◽  
Industrial Robots ◽  
Analysis Model

Within the context of the large-scale application of industrial robots, methods of analyzing the life-cycle cost (LCC) of industrial robot production have shown considerable developments, but there remains a lack of methods that allow for the examination of robot substitution. Taking inspiration from the symmetry philosophy in manufacturing systems engineering, this article further establishes a comparative LCC analysis model to compare the LCC of the industrial robot production with traditional production at the same time. This model introduces intangible costs (covering idle loss, efficiency loss and defect loss) to supplement the actual costs and comprehensively uses various methods for cost allocation and variable estimation to conduct total cost and the cost efficiency analysis, together with hierarchical decomposition and dynamic comparison. To demonstrate the model, an investigation of a Chinese automobile manufacturer is provided to compare the LCC of welding robot production with that of manual welding production; methods of case analysis and simulation are combined, and a thorough comparison is done with related existing works to show the validity of this framework. In accordance with this study, a simple template is developed to support the decision-making analysis of the application and cost management of industrial robots. In addition, the case analysis and simulations can provide references for enterprises in emerging markets in relation to robot substitution.

Design of Ultrasonic Ranging Circuit Based on STC Microcontroller

2013 ◽  
Vol 722 ◽  
pp. 59-63
Author(s):  
Rui Luo ◽  
Zi Hong Zhang
Keyword(s):  
System Performance ◽  
Temperature Compensation ◽  
Measurement Accuracy ◽  
Environmental Temperature ◽  
Detection Distance ◽  
Compensation Circuit ◽  
High Measurement ◽  
Ultrasonic Ranging ◽  
Allowable Range ◽  
Market Promotion

In this paper, based on the 18B20 temperature compensation circuit for ultrasonic ranging circuit, can eliminate the influence of environmental temperature on ultrasonic velocity, this paper introduced the ultrasonic ranging system, the system includes ultrasonic transmitting circuit, receiving circuit and display circuit, the results of the experiment show that, the system detection distance can be up to 12M, the error is in the allowable range, the range finder the system performance is stable, high measurement accuracy, distance, has a certain practicality and market promotion value.

Performance Analysis and Validation of Precision Multisatellite RF Measurement Scheme for Microsatellite Formations

2021 ◽  
Author(s):  
Chen Lin ◽  
Xiaojun Jin ◽  
Shiming Mo ◽  
Cong Hou ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Multiple Access ◽  
High Performance ◽  
Large Scale ◽  
Measurement Accuracy ◽  
Media Access Control ◽  
Satellite Measurement ◽  
Measurement Scheme ◽  
Rf Measurement ◽  
Code Division Multiple ◽  
Time Division

Abstract Almost all existing studies on inter-satellite radio frequency (RF) measurement have focused on two-satellite formations. Although some frequency division multiple access and code division multiple access multisatellite RF measurement schemes have been proposed, their poor scalability does not satisfy the inter-satellite measurement requirements of multisatellite formations, especially large-scale formations. Two-way ranging (TWR), which is based on a time division mechanism, is an effective solution that has been used for inter-satellite links in the global positioning system and Beidou navigation constellations. However, the high measurement accuracy achieved with TWR in these navigation constellations is heavily reliant on high-performance atomic clocks and the assistance of navigation ephemeris, which are not available on microsatellite platforms. This work focuses on a scalable multisatellite measurement scheme that adopts a distributed broadcast-based time division multiple access mechanism as the media access control layer and uses an asymmetric double-side TWR method as the physical layer. The measurement performance of the proposed scheme is evaluated through in-depth theoretical modeling, simulation verification, and experimental validation, along with a comprehensive comparison with the conventional TWR method. The experimental results show that centimeter-level measurement accuracy can be achieved with the proposed scheme when only a common miniaturized frequency source is used. This accuracy level is two orders of magnitude better than that of the TWR method, and thus satisfies the application requirements of general large-scale microsatellite formations.

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