Virtual projective shape matching in targetless CAD-based close-range photogrammetry for efficient estimation of specific deviations

Bergström, Per; Fergusson, Michael; Sjödahl, Mikael

doi:10.1117/1.oe.57.5.053110

Cited by 13 publications

(6 citation statements)

References 33 publications

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“…After that, the CAD model is used to provide the initial position of the three dimensional (3D) hole, and then the parameters of the 3D hole are optimized by minimizing the distance between the projec tion of the 3D hole on images and the refined hole edge. Their method is also useful for online measurement [17]. However, the method sometimes fails when the boundary of the hole is very fuzzy, as shown in figure 2.…”

Section: Related Workmentioning

confidence: 99%

An accurate and robust method for the measurement of circular holes based on binocular vision

Xia

Zhao

et al. 2019

Meas. Sci. Technol.

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Circular holes in industrial parts are a very important feature which are often used as assembly references for other parts, so accurate measurement is required. Measurement of circular holes based on computer vision is a promising method but also very challenging, because it is tricky to find the edge of a hole accurately in an image. In this paper, an accurate and robust method for the measurement of circular holes is proposed. Firstly, highly trusted edge points of the hole are found based on pixel intensity information. Secondly, a new energy function model based on the epipolar geometry constraint is introduced to obtain the optimal edges of the hole. Finally, a spatial circular hole is accurately reconstructed by using the points on the optimized edges as input to a threedimensional reconstruction method. Our experimental result shows that the proposed method could measure various circular holes from different views with an error of around 0.05 mm.

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Section: Related Workmentioning

confidence: 99%

An accurate and robust method for the measurement of circular holes based on binocular vision

Xia

Zhao

et al. 2019

Meas. Sci. Technol.

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“…They further state that it is necessary to understand the process, quality thresholds, and which process parameters have certain effects on the final result of the output. This work is in line with the most recent contributions to ZDM from our research group, where we intend to integrate and combine a number of areas and disciplines from input to output in the production process, in order to reach zero defects; these are, e.g., [7,8,[24][25][26]. Our view on ZDM is that we do not consider it is possible to reach zero defects in the production process, but that the most important objective is that no outputs or products outside of specifications can reach the next step in a value chain or the customer.…”

mentioning

confidence: 71%

An Initial Model for Zero Defect Manufacturing

Lindström¹,

Kyösti

Birk

et al. 2020

Applied Sciences

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This paper investigates an initial model for Zero Defect Manufacturing (ZDM) using a cost function where the operation and condition of a production process are reflected, and the quality of the output/product and the production process (as well as safety aspects) can be considered. The outset of the study is based on empirical data collected from five manufacturing companies, and proposes an initial model for ZDM with an Industry 4.0 perspective. The initial ZDM model has a generic setup for a real-life system and its replication as a digital twin using system models based on a representation of a generic production process with its connected control system, and potential interconnections between unit processes. It is based on concepts from system theory of dynamic systems and principles from condition monitoring and fault detection. In that way the model is deemed as highly generalizable for manufacturing and process industry companies as well as for some critical infrastructures with production and distribution systems. The proposed model with its cost function setup is analyzed and discussed in the context of ZDM. It is concluded that production processes in the manufacturing and process industry can be made more intelligent and interoperable using this approach. Improved sustainability, competitiveness, efficiency and profitability of companies are foreseen welcomed secondary effects. Finally, the proposed ZDM model further develops the ZDM by adding to it a systematic approach based on a solid mathematical foundation.

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“…The main assumption in a smart assembly line is that this trend will continue and in a near future, scanning all produced parts can be done even faster and cheaper than now (Söderberg et al 2017). For instance, Bergström, Sjödahl, and Fergusson (2018) has developed an online shape inspection method that deviations of all produced parts from their nominal can be obtained just by taking some pictures from each part and analysing those pictures in a short time. Another assumption is that the assembly line will be robotised enough that the amount of time and workforce that will be added due to implementing selective assembly is reasonable.…”

Section: Selective Assemblymentioning

confidence: 99%

Developing a selective assembly technique for sheet metal assemblies

Aderiani

Wärmefjord

Söderberg

et al. 2019

International Journal of Production Research

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Applying the concept of Digital Twin in production processes supports the manufacturing of products of optimal geometry quality. This concept can be further supported by a strategy of finding the optimal combination of individual parts to maximise the geometrical quality of the final product, known as selective assembly technique. However, application of this technique has been limited to assemblies where the final dimensions are just function of the mating parts' dimensions and this is not applicable in sheet metal assemblies. This paper develops a selective assembly technique for sheet metal assemblies and investigates the effect of batch size on the improvements. The presented method utilises a variation simulation tool (Computer-Aided Tolerancing tool) and an optimisation algorithm to find the optimal combination of the mating parts. The approach presented is applied to three industrial cases of sheet metal assemblies. The results show that using this technique leads to a considerable reduction of the final geometrical variation and mean deviation for these kinds of assemblies. Moreover, increasing the batch size reduces the amount of achievable improvement in variation but increases the amount of achievable improvement in the mean deviation.

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Virtual projective shape matching in targetless CAD-based close-range photogrammetry for efficient estimation of specific deviations

Cited by 13 publications

References 33 publications

An accurate and robust method for the measurement of circular holes based on binocular vision

An accurate and robust method for the measurement of circular holes based on binocular vision

An Initial Model for Zero Defect Manufacturing

Developing a selective assembly technique for sheet metal assemblies

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