Free-form contour packing based on material grid approximation and lowest-gravity-center methods

Peng

et al. 2019

IEEE Access

Self Cite

Dental restoration is a complex process to recover patients' teeth using artificial materials. It is important to improve the utilization of the expensive material for cost saving. The tooth side surface is projected as a two-dimensional (2D) contour in the actual processing, which forms a packing problem of irregular contours. The 2D irregular packing has received a lot of attention in research to solve this NP-hard problem. Contours of the dental restoration are more complicated than those in traditional 2D irregular packing problems. The existing packing methods cannot obtain good results for these complex contours. In order to solve the contour packing problem of restoration models using the NC machining technology, a dental restoration contour packing algorithm is proposed based on the contour similar feature matching and collision. The algorithm uses dynamic programming for the longest common subsequence to search the solution of 2D free contour packing. Comparing with the existing packing methods, our proposed method can significantly reduce the processing time and improve the filling rate.INDEX TERMS Computer-aided prosthodontics, similar feature matching, nesting, free-form contour packing, freeman chain code, geometric invariant description.

Section: Resultsmentioning

confidence: 99%

Section: Encoding Contours With Freeman Chain Code (Fcc) and Expound Geometric Invariant Modelmentioning

confidence: 99%

Dental Restorations Packing Based on the Contour Similar Features Matching and Collision Strategy

Peng

et al. 2019

IEEE Access

Self Cite

“…In earlier times, three scholars (Segenreich and Faria Braga, 1986;Oliveira and Ferreira, 1993;Ramesh Babu and Ramesh Babu, 2001) gave different interpretations of the raster method. In recent years, the raster method has been widely used in 2D irregular layout packing problems (Guo, Peng, Cheng, Dai;Sato et al, 2016;Mundim et al, 2017). Computer vision was also used in 2D irregular packing problems (Bouganis and Shanahan, 2007).…”

Section: Geometric Approachmentioning

confidence: 99%

Two-dimensional irregular packing problems: A review

et al. 2022

Front. Mech. Eng.

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Two-dimensional (2D) irregular packing problems are widespread in manufacturing industries such as shipbuilding, metalworking, automotive production, aerospace, clothing and furniture manufacturing. Research on 2D irregular packing problems is essential for improving material utilization and industrial automation. Much research has been conducted on this problem with significant research results and certain algorithms. The work has made important contributions to solving practical problems. This paper reviews recent advances in the domain of 2D irregular packing problems based on a variety of research papers. We first introduce the basic concept and research background of 2D irregular packing problems and then summarize algorithms and strategies that have been proposed for the problems in recent years. Conclusion summarize development trends and research hotspots of typical 2D irregular shape packing problems. We hope that this review could provide guidance for researchers in the field of 2D irregular packing.

“…Different algorithms have been proposed for positioning problems but none of them can provide an optimal layout solution. Guo et al [13] proposed a contour packing algorithm for free-form contour machining, which discretizes the packing area of materials based on the bottom-left and the lowest gravity center stray. This algorithm finds the position by collided the contour after rotating it, thus it belongs to the trial solution method (TSA) and takes a lot of time to obtain a satisfied result.…”

Section: Related Researchmentioning

confidence: 99%

Efficient Free-Form Contour Packing Based on Code Matching Strategy

et al. 2019

IEEE Access

Self Cite

Freeform surfaces exist widely in the stock cutting process of clinical prosthesis preparation, aviation, ship, and other manufacturing industries. The free-form contours of surfaces need to be packed before they are machined from raw materials. The existing methods search a contour position by rotating the contour and translating it to connect other contours for packing. The relative position between two contours will be changed after the rotation as the contour description is lack of geometric invariance. These methods easily miss the best layout position resulting in interspaces in the raw material. Moreover, this result seriously reduces the performance and efficiency of an automatic packing system. Therefore, a new packing algorithm is proposed in this paper by combining the geometric invariant description and coding matching for contours to solve the contour rotating and position connecting problems. The optimal position of a contour can be found directly and then connected by the extracted similar complement features of the contour. The experimental results show that the proposed method can greatly improve quality and efficiency of the layout, especially in the material utilization. INDEX TERMS Computer graphics, code matching, shape, free-form contour packing, freeman chain code, geometric invariant description, layout.