Abstract: A method for detecting abnormal direct current voltage measurement in a modular multilevel converter high voltage direct current transmission system is provided. In the method, a valve group voltage at a detection pole is obtained, voltages at voltage measurement points at the detection pole are collected, and comparison and determination are performed based on the actual arrangement of the voltage measurement points, and then whether an abnormal measurement occurs at each of the voltage measurement points is determined.

Abstract: A laser cutting method for irregular parts based on machine vision includes: (A) obtaining and numbering vertices of all parts on the layout diagram; (B) planning a part vertex set and an empty cutting path vertex set; (C) obtaining a shortest empty cutting path and the empty cutting path vertex set with the shortest empty cutting path; (D) cutting the parts one by one according to an order obtained by the CPLEX algorithm. This application further provides a laser cutting system.

Abstract: A laser cutting method for irregular parts based on machine vision includes: (A) obtaining and numbering vertices of all parts on the layout diagram; (B) planning a part vertex set and an empty cutting path vertex set; (C) obtaining a shortest empty cutting path and the empty cutting path vertex set with the shortest empty cutting path; (D) cutting the parts one by one according to an order obtained by the CPLEX algorithm. This application further provides a laser cutting system.

Abstract: A method for creating a knowledge representation model for a product includes: systematically capturing and representing knowledge and experience generated in product design and production processes, classifying the knowledge into five aspects, namely requirement, function, behavior, structure and evolution, and transforming unstructured tacit knowledge into structured knowledge in terms of know-what, know-how and know-why. Based on the knowledge representation model and knowledge bases, the present invention can be used to guide the construction of corresponding geometric model libraries, material libraries and process libraries, etc., and then to create design big data. The present invention can also be combined with an intelligent recommendation algorithm to intelligently recommend relevant data, information and knowledge based on the design engineers' working context and tasks undertaken.