A study of car control and assignment problem in MCE systems using hybrid method

As the height of buildings grows, the demand of enhancing transportation capacity in buildings has been increasing. One of the solutions could be increasing the number of elevator shafts. A dilemma, however, exists that most of the floor space is occupied by the elevator shafts if a lot of elevator shafts were installed. Therefore, multi-car elevator (MCE) systems, which have several elevator cars in a shaft, attracts people´s attention. Optimization of car control and call assignment is necessary to control MCE systems safety and transport passengers rapidly. We have been studying the optimization problem, which is called a car control and assignment problem (CCAP) in MCE systems, and proposed Integer Program (IP) and Mixed Integer Program (MIP). They, however, have a problem that it takes long time to solve. In this paper, we propose a new method, which is called a Hybrid solving Method for Mce systems (HMM), solving the CCAP using Mixed Integer Program (MIP) and Constraint Program (CP), and evaluate it through computational experiments.