Virtual Environment-based real time intergrated control of heterogenous robots for dissimilar metal WAAM = 가상환경 기반 이기종 로봇 실시간 통합 제어 플랫폼 개발을 통한 이종금속 적층제조 구현

국문 초록 (Abstract)

와이어 아크 적층 제조(WAAM) 공정은 아크 플라즈마 열원을
기반으로 금속 와이어를 용융시키고, 이를 응고시키며 layer by layer로
적층하여 부품을 제작하는 기술이다. 이 기술은 특히 대형 부품을
제조하기에 유리하며, 항공우주, 원자력, 방산 분야 등에 적용 될 수 있다.
이러한 첨단 산업에 사용되는 부품은 고온 및 고압과 같은 극한 환경에
노출되므로 우수한 기계적 특성이 요구된다. 그러나 고성능 재료가 제품
전체에 일률적으로 적용될 경우, 부위별로 요구되는 성능의 차이가 있기
때문에 과도한 기계적 성능으로 인한 제조 효율의 저하와 생산 비용의
증가가 야기될 수 있으며 이에 대한 해결책으로 다중 로봇 제어를 통한
WAAM 기반 이종 금속 적층 제조 기술을 적용 시킬 수 있다. 다중
로봇을 사용하는 실제 산업 현장에는 다양한 제조사의 로봇이 사용되고
있기 때문에 이기종 로봇 간의 좌표계, 언어, 소프트웨어 등 제어 체계의
차이로 인한 충돌 발생 우려, 로봇 간 동기화 등의 문제가 존재한다.
본 연구에서는 상용 소프트웨어 RoboDK를 이용하여 가상환경 기반 이
기종 로봇 실시간 통합 제어 플랫폼을 개발하여 가상 환경의 로봇에서 로
봇의 동작을 실제 로봇에 실시간으로 적용 시키고 사전 충돌 감지를 적용
시켜 이기종 로봇 간 좌표계, 언어 등의 차이에 기인한 동기화 문제 및
충돌 발생의 문제를 해결하였다. 이를 바탕으로 Inconel 718과 STS 316L
금속 와이어를 사용하여 각 로봇이 송급하는 와이어 간 거리를 정밀하게
제어함으로써 이종 금속 비드를 구현하였다. 이종 금속 간 접합부에서 발
생하는 급격한 재료 변화는 잔류 응력과 변형 문제를 야기할 수 있기 때
문에, 주사전자현미경(SEM) 및 에너지 분산형 분광 분석(EDS)을 통해
와이어 간 거리에 따른 이종금속 접합부의 미세조직과 Nb 성분 분포 변
화를 관찰하였다.

목차 (Table of Contents)

• I. Introduction ··················································································································· 7
• Ⅱ. Virtual environment based heterogenous robot control platform setup ····12
• 2.1. Heterogeneous robot communication framework ········································12
• 2.2. Virtual-to-real robot control implementation ···············································17
• Ⅲ. Implementation of dissimilar metal beads ·························································20
• 3.1. Experimental setup ······························································································19
• 3.2. Experimental evaluation of dissimilar metal beads ····································24
• 3.3. EDS analysis of mixing behavior in dissimilar metal ······························30
• Ⅳ. Dissimilar metal WAAM process ········································································38
• 4.1. Structural analysis of dissimilar metals ························································38
• 4.2. Dissimilar metal WAAM for turbine blade fabrication ····························42
• Ⅴ. Result ··························································································································· 46
• ⅤI. Conclusion ················································································································· 49
• Reference ···························································································································· 50
• 국문 초록··························································································································· 52
• 감사의 글 ························································································································· 53