An automated modelling system was developed to use a directed energy deposition equipment (DED) easily without doing trial-and-error processes for determination of modelling parameters. In the development of the system, the stand-off distance (SOD) between the nozzle and the melt pool was measured in-process and modeling paths having the optimum SOD were automatically generated in real time. The SOD was measured in 0.3 s in the case of using a still image during a modeling process or in 0.1 s in the case of using a flame image of a continuous images after modeling a layer. The system realized automatic modeling with the optimum SOD. However, it caused a lack of modeling at edge parts. In order to solve the problem, a high accuracy modeling system was developed by re-modeling areas with lack of shape which were detected by recognizing the modeled shape of each layer using the measured discrete SODs. In addition, an automatic mold repair system was developed using the automated modelling system. The usefulness of the entire system was then verified through modelling experiments.

The present study shows the significant impact of the type and mass concentration of additives in sliding surface lubricating oil for machine tools on friction characteristics. The performance of different sliding surface lubricating oil for machine tools was evaluated using a drive table equipped with a linear motor and slide-guide way. Specifically, the response to command input and driving force at constant feed rate were investigated for each lubricant. Experimental results showed that the lubricant containing alkyl acid phosphate resulted in a lower friction force during sliding and a shorter settling time compared to the lubricant containing oleic acid. By incorporating a friction model based on the experimental results into a model of the feed drive system, the position and friction force during step positioning were simulated. Although the simulation could not perfectly reproduce the actual friction force, it was able to qualitatively reproduce the overshoot and undershoot caused by friction.