Date on Master's Thesis/Doctoral Dissertation
Heragu, Sunderesh S.
Parking garages--Automation; Parking garages--Design and construction
Automated vehicle storage/retrieval system (AVS/RS) technology is relatively new. It has been applied successfully in several European facilities in 1990s. AVS/RS is a flexible system that is a viable alternative to automated storage/retrieval systems (AS/RS), a traditional material handling technology that has been in existence for more than fifty years. There are very few papers in the literature that focus on the use of analytical models for estimating performance measures of AVS/RS. In this thesis, queuing network theory is used to model an AVS/BS system to analyze its performance. The manufacturing system performance analyzer (MPA) is an open queuing network (OQN) analyzer based on the parametric decomposition method. This thesis models the AVS/RS and uses MPA to analyze the performance of an AVS/RS configuration. A simulation model based on discrete events is also generated by Promodel to allow comparison of MPA results with those of simulation. A web interface for conceptualizing AVS/RS and AS/RS designs is presented in this thesis. This on-line tool provides a convenient and friendly interface between warehouse designers and time analytical model tool. Pour case studies of algorithms embedded in the web interface are presented in the thesis. An initial warehouse design is first analyzed by MPA. After this, several improvements of this initial design are evaluated. Experimental results are provided to show that the OQN methodology can he applied effectively to analyze an AVS/RS when vehicle utilization is between 60% and 85%. MPA is a better choice than simulation to quickly evaluate alterilate configuration of the AVS/RS. Additionally, two more experiments are conducted to compare MPA with another AVS/RS system performance analyzer. MPA models AVS/RS under the tier-captive configuration, whereas the other model assumes the tier-to-tier configuration.
Cai, Xiao, "Analytical modeling of an autonomous vehicle storage/retrieval system." (2007). Electronic Theses and Dissertations. Paper 196.