A Simulation Model for Opportunistic Electrode Replacement in a Robotic Manufacturing Process

摘要

This paper addresses the electrode replacement problem for a common robotic manufacturing process (for reasons of confidentiality, all application specific information has been replaced using generic terms) consisting of k non-identical robots and the general maintenance optimization problem. The electrode tip wear compensation methodology is introduced. Three kinds of replacement: correction replacement, preventive replacement and opportunistic replacement policies are described. Polynomial models have been used to predict future tip behavior by modeling the tip wear from field data. Manufacturing process order and time analysis results show that most tips last about 9-11 hours and each operation sequence takes approximately 20 seconds in this product line. Based on this, a tip wear trend as well as high and low limits for tip usage were established. Subsequently, the recommended and maximum number left on a given tip and the corresponding remaining lifetime for a specific tip can be obtained. The expected failure time or replacement time can also be predicted. Through a careful cost investigation, a simulation model for electrode tip opportunistic replacement on a 6-robot manufacturing system has been developed. Based on some assumptions made, an optimum opportunistic electrode replacement policy, based on minimum cost, is acquired. The total expected cost, tip replacement number, production line stoppage times and next replacement time can also be obtained.