Abstract:In Industrie 4.0, machines are expected to become autonomous, self-aware and self-correcting. One important step in the area of manufacturing is feature recognition that aims to detect all the machining features from a 3D model. In this research area, recognising and locating a wide variety of highly intersecting features are extremely challenging as the topology information of features is substantially damaged because of the feature intersection. Motivated by the single shot multibox detector (SSD), this pape… Show more
“…Many works approached AFR from a 2D perspective, such as multiple sectional view network (MsvNet) and single shot multibox detector network (SsdNet) proposed by Refs. 28,29 , which used 2D CNNs to learn 2D views of the 3D part models from different angles. However, 2D-view based methods lost the geometric and topological information of 3D part models and even had difficulty accurately locating the machined surfaces.…”
The integration of computer-aided design (CAD), computer-aided process planning (CAPP), and computer-aided manufacturing (CAM) systems is significantly enhanced by employing deep learning-based automatic feature recognition (AFR) methods. These methods outperform traditional, rule-based approaches, particularly in handling the complexities of intersecting features. However, existing deep learning-based AFR methods face two major challenges. The initial challenge stems from the frequent utilization of voxelized or point-cloud representations of CAD models, resulting in the unfortunate loss of valuable geometric and topological information inherent in original Boundary representation (B-Rep) models. The second challenge involves the limitation of supervised deep learning methods in identifying machining features that are not present in the predefined dataset. This constraint renders them suboptimal for the continually evolving datasets of real industrial scenarios. To address the first challenge, this study introduces a graph-structured language, Multidimensional Attributed Face-Edge Graph (maFEG), crafted to encapsulate the intricate geometric and topological details of CAD models. Furthermore, a graph neural network, Sheet-metalNet, is proposed for the efficient learning and interpretation of maFEGs. To tackle the second challenge, a three-component incremental learning strategy is proposed: an initial phase of pre-training and fine-tuning, a prototype sampling-based replay, and a stage employing knowledge distillation for parameter regularization. The effectiveness of Sheet-metalNet and its complementary incremental learning strategy is evaluated using the open-source MFCAD++ dataset and the newly created SMCAD dataset. Experimental results show that Sheet-metalNet surpasses state-of-the-art AFR methods in machining feature recognition accuracy. Moreover, Sheet-metalNet demonstrates adaptability to dynamic dataset changes, maintaining high performance when encountering newly introduced features, thanks to its innovative incremental learning strategy.
“…Many works approached AFR from a 2D perspective, such as multiple sectional view network (MsvNet) and single shot multibox detector network (SsdNet) proposed by Refs. 28,29 , which used 2D CNNs to learn 2D views of the 3D part models from different angles. However, 2D-view based methods lost the geometric and topological information of 3D part models and even had difficulty accurately locating the machined surfaces.…”
The integration of computer-aided design (CAD), computer-aided process planning (CAPP), and computer-aided manufacturing (CAM) systems is significantly enhanced by employing deep learning-based automatic feature recognition (AFR) methods. These methods outperform traditional, rule-based approaches, particularly in handling the complexities of intersecting features. However, existing deep learning-based AFR methods face two major challenges. The initial challenge stems from the frequent utilization of voxelized or point-cloud representations of CAD models, resulting in the unfortunate loss of valuable geometric and topological information inherent in original Boundary representation (B-Rep) models. The second challenge involves the limitation of supervised deep learning methods in identifying machining features that are not present in the predefined dataset. This constraint renders them suboptimal for the continually evolving datasets of real industrial scenarios. To address the first challenge, this study introduces a graph-structured language, Multidimensional Attributed Face-Edge Graph (maFEG), crafted to encapsulate the intricate geometric and topological details of CAD models. Furthermore, a graph neural network, Sheet-metalNet, is proposed for the efficient learning and interpretation of maFEGs. To tackle the second challenge, a three-component incremental learning strategy is proposed: an initial phase of pre-training and fine-tuning, a prototype sampling-based replay, and a stage employing knowledge distillation for parameter regularization. The effectiveness of Sheet-metalNet and its complementary incremental learning strategy is evaluated using the open-source MFCAD++ dataset and the newly created SMCAD dataset. Experimental results show that Sheet-metalNet surpasses state-of-the-art AFR methods in machining feature recognition accuracy. Moreover, Sheet-metalNet demonstrates adaptability to dynamic dataset changes, maintaining high performance when encountering newly introduced features, thanks to its innovative incremental learning strategy.
“…However, the performance of learning-based methods highly relies on the accuracy of feature segmentation. It is rather difficult to accurately segmenting intersecting features according to the shape information, since the topology information of the features might be destroyed because of feature intersection [32]. Moreover, when a new feature is introduced to the system, the model must be entirely retrained using all training features.…”
Automatic manufacturing feature recognition (AFR) is a critical technology for realizing CAD/CAPP/CAM integration in the era of intelligent manufacturing. Despite the numerous feature recognition approaches that have been proposed, the recognition of intersecting features remains a challenge. The most important reason is that the boundaries of features and their geometric topological information are altered or destroyed when interacting with other features. To address this problem, this paper proposes a manufacturing feature recognition method based on graph and minimum nonintersection feature volume suppression. Firstly, the geometric and topological information of a part is extracted and represented as an attributed adjacency graph. Then, a subgraph isomorphism algorithm is designed to recognize the features corresponding to each subgraph. After that, a method to construct and suppress the minimum non-intersection volume of the recognized features is introduced to repair the boundaries of intersecting features. On this basis, the intersecting features on the solid model are separated and recognized at different stages. The experimental results indicate that the proposed approach is effective in recognizing intersection features. Moreover, the recognition result of the proposed method incorporates the surface and volume of a feature, providing enriched feature information for engineering applications.
“…The 2D images produced are segmented to isolate individual features using the selective search algorithm, then individual feature representations are used as the input to a 2D CNN which performs feature recognition. This architecture was improved on in [13], which presented SsdNet, in which segmentation and feature recognition are combined into a single process based on the single shot multibox detector (SSD) [14]. In [15], PointNet++ [10], a hierarchical network which makes use of point cloud data, is used to perform both single-feature classification and multi-feature recognition.…”
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