Journal of the Korea Society for Simulation (한국시뮬레이션학회논문지)

The Korea Society for Simulation (한국시뮬레이션학회)
권호 표지
DOI QR코드

DOI QR Code

An Online Forklift Dispatching Algorithm Based on Minimal Cost Assignment Approach

최소 비용할당 기반 온라인 지게차 운영 알고리즘

  • Received : 2018.03.14
  • Accepted : 2018.04.16
  • Published : 2018.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

Forklifts in a shipyard lift and transport heavy objects. Tasks occur dynamically and the rate of the task occurrence changes over time. Especially, the rate of the task occurrence is high immediately after morning and afternoon business hours. The weight of objects varies according to task characteristic, and a forklift also has the workable or allowable weight limit. In this study, we propose an online forklift dispatching algorithm based on nearest-neighbor dispatching rule using minimal cost assignment approach in order to attain the efficient operations. The proposed algorithm considers various types of forklift and multiple jobs at the same time to determine the dispatch plan. We generate dummy forklifts and dummy tasks to handle unbalance in the numbers of forklifts and tasks by taking their capacity limits and weights. In addition, a method of systematic forklift selection is also devised considering the condition of the forklift. The performance indicator is the total travel distance and the average task waiting time. We validate our approach against the priority rule-based method of the previous study by discrete-event simulation.

조선소의 지게차는 작업 특성상 무거운 물건을 상/하차하거나 이송하는 작업이 빈번하다. 작업은 동적이며 시간대별로 생성 비율이 다르다. 특히 오전과 오후 업무시간 직후에 작업 발생 비율이 높은 경향을 보인다. 이러한 상/하차 작업과 이송작업의 무게는 매번 다르며, 활용되는 지게차 역시 작업 가능한 허용무게의 제약이 있다. 본 연구에서는 지게차의 원활한 운영을 위해 최소 비용할당을 사용한 최근린 배차 규칙 알고리즘을 제안한다. 제시된 알고리즘은 다양한 종류의 지게차와 다수의 작업을 동시에 고려하여 배차를 결정하며, 지게차 종류에 따른 작업 불가능을 고려하기 위해 가상 지게차와 가상 작업을 생성하는 방법을 제안한다. 그리고 차량의 상태를 고려하여 체계적으로 지게차를 선택하는 방법도 함께 제시한다. 성능지표는 평균 공차이동거리와 평균 작업대기시간으로 한다. 성능비교를 위해 조선소의 지게차 운영방식을 모델링한 우선순위 규칙을 비교 대상으로 한다. 시뮬레이션을 통해 제시한 알고리즘의 우수성을 확인한다.

Keywords

References

  1. Bilge, U., Esenduran, G., Varol, N., Ozturk, Z., Aydin, B. and Alp, A., "Multi-attribute responsive dispatching strategies for automated guided vehicles", International Journal of Production Economics, Vol. 100, No. 1, pp. 65-75, 2006. https://doi.org/10.1016/j.ijpe.2004.10.004
  2. Cho, K.K., Chung, K.H., Park, C., Park, J.C. and Kim, H.S., "A spatial scheduling system for block painting process in shipbuilding", CIRP Annals-Manufacturing Technology, Vol. 50, No. 1, pp. 339-342, 2001. https://doi.org/10.1016/S0007-8506(07)62135-0
  3. Confessore, G., Fabiano, F. and Liotta, G., "A network flow based heuristic approach for optimising AGV movements", Journal of Intelligent Manufacturing, Vol. 24, No. 2, pp. 405-419, 2013. https://doi.org/10.1007/s10845-011-0612-7
  4. Dean, S.F., "Why the closest ambulance cannot be dispatched in an urban emergency medical services system", Prehospital and Disaster Medicine, Vol. 23, No. 2, pp. 161-165, 2008. https://doi.org/10.1017/S1049023X00005793
  5. Hayes, J., Moore, A., Benwell, G. and Wong, B., "Ambulance dispatch complexity and dispatcher decision strategies: implications for interface design", Asia-Pacific Conference on Computer Human Interaction, pp. 589-593, 2004.
  6. Han, C.K., Kwon, B.B., Kim, B.H., Jeong, R.G., Lee, H. and Ha, B.H., "An online personal rapid transit dispatching algorithm based on nearest neighbor dispatching rule", Journal of the Korea Society for Simulation, Vol. 23, No. 4, pp. 97-109, 2014. https://doi.org/10.9709/JKSS.2014.23.4.097
  7. Han, C.K., Kim, B.H., Jeong, R.G. and Ha, B.H., "A dispatching and routing algorithm for personal rapid transit by considering congestion", The Transactions of The Korean Institute of Electrical Engineers, Vol. 64, No. 11, pp. 1578-1586, 2015. https://doi.org/10.5370/KIEE.2015.64.11.1578
  8. Ho, Y.C. and Liu, H.C., "A simulation study on the performance of pickup-dispatching rules for multiple-load AGVs", Computers & Industrial Engineering, Vol. 51, No. 3, pp. 445-463, 2006. https://doi.org/10.1016/j.cie.2006.08.007
  9. Ingmar, A., "Reallocation of empty PRT vehicles en route," Transportation Research Record: Journal of the Transportation Research Board, Vol. 1838, 2003.
  10. Joo, C.M. and Kim, B.S., "Block transportation scheduling under delivery restriction in shipyard using meta- heuristic algorithms", Expert Systems with Applications, Vol. 41, No. 6, pp. 2851-2858, 2014. https://doi.org/10.1016/j.eswa.2013.10.020
  11. Koh, S.G., Park, J.C., Choi, Y.S. and Joo, C.M., "Development of a block assembly scheduling system for shipbuilding company", IE Interfaces, Vol. 12, No. 4, pp. 586-594, 1999.
  12. Koh, S.G., Jang, J.H., Choi, D.W. and Woo, S.B., "Spatial scheduling for mega-block assembly yard in shipbuilding company", IE interfaces, Vol. 24, No. 1, pp. 78-86, 2011. https://doi.org/10.7232/IEIF.2011.24.1.078
  13. Kwon, B.B., Han, C.K., Son, J.R. and Ha, B.H., "A simulation model for evaluating forklift dispatching policies in shipyard", The 1st East Asia Workshop on Industrial Engineering, 2014.
  14. Lee, W.S., Lim, W.I. and Koo, P.H., "Transporter scheduling based on a network flow model under a dynamic block transportation environment", Computers & Industrial Engineering, 2009. CIE 2009. International Conference on, pp. 311-316, 2009.
  15. Lees-Miller, J.D., "Empty vehicle redistribution for personal rapid transit", Ph.D Thesis, Bristol University, 2011.
  16. Lee, S., "The role of centrality in ambulance dispatching", Decision Support Systems, Vol. 54, No. 1, pp. 282- 291, 2012. https://doi.org/10.1016/j.dss.2012.05.036
  17. Park, C. and Seo, J.A., "GRASP approach to transporter scheduling and routing at a shipyard", Computers & Industrial Engineering, Vol. 63, No. 2, pp. 390-399, 2012. https://doi.org/10.1016/j.cie.2012.04.010
  18. Roh, M.I. and Cha, J.H.A., "block transportation scheduling system considering a minimization of travel distance without loading of and interference between multiple transporters", International journal of production research, Vol. 49, No. 11, pp. 3231-3250, 2011. https://doi.org/10.1080/00207543.2010.484427
  19. Savelsbergh, M.W.P., "Local Search in Routing Problems with Time Windows", Annals of Operations research Vol. 4, No. 1, pp. 285-305, 1985. https://doi.org/10.1007/BF02022044
  20. Zhicheng, B., Weijian, M., Xiaoming, Y., Ning, Z. and Chao, M., "Modified Hungarian algorithm for real- time ALV dispatching problem in huge container terminals", Journal of Networks, Vol. 9, No. 1, pp. 123-130, 2014.