CNC Machine Toolauxiliary Maintenance Technology Based On Augumented Reality

The efficiency and quality of CNC machine tool fault maintenance is an important guarantee to improve its economy and reliability.The traditional way of maintenance is that maintenance personnel consult the paper or electronic technical manual and rely on experience to complete the complex maintenance process,resulting in low maintenance efficiency and difficult quality assurance.In this paper,augmented reality(AR)technology and maintenance case knowledge modeling technology are used to provide a new technical means for the maintenance process of CNC machine tools.The main work is as follows:(1)The composition and characteristics of the information elements of maintenance cases of CNC machine tools is analyzed,and the ontology method is used to build the knowledge model of maintenance cases and constructs the ontology database of maintenance cases.(2)A two-layer maintenance case knowledge retrieval framework based on ontology semantic similarity and case-based reasoning(CBR)is adopted: in the first layer,the fault location and fault mode are used as keywords,and the distance based semantic similarity algorithm is used to preliminarily select the maintenance cases to obtain the primary case set.In the second layer,CBR method is used to match the primary case set according to the state characteristic data when the fault occurs,and the most similar maintenance cases are retrieved.(3)The maintenance guidance tool under AR environment is constructed: using identification method to achieve high-precision 3D tracking registration;integrating three human-computer interaction methods including gesture,voice and eye tracking to achieve information guidance in the maintenance process;using audio / video communication and image annotation method to achieve remote experts’ online guidance.(4)Development and verification of the prototype system: through the integration of the above results,a CNC machine tool maintenance guidance system based on Holo Lens glasses was developed,and the effectiveness of the prototype system was verified through the chain tool library "tool base origin loss fault".Aiming at the problems of low efficiency and difficult quality control of traditional CNC machine maintenance,this paper uses ontology method to build a knowledge-based maintenance case model,and designs a maintenance case retrieval technology based on ontology and CBR according to this model.The maintenance process information model was established,and the maintenance knowledge management system was established based on the model,which was used to manage the maintenance case knowledge ontology and its AR guided visual elements.The maintenance guidance tools under AR environment are designed,including remote expert guidance,human-computer interaction and 3D tracking registration.Finally,the prototype system is developed and verified.