THE PALLET CONVEYOR SYSTEM APPLICATION IN THE INDUSTRIAL LINES - A NEW DESIGN SYSTEM WITH IMPROVEMENT OF PRODUCTIVITY

The design and operation of a high volume conveyor sortation system are important due to its high cost, large footprint and critical role in the system. In this thesis, we study the characteristics of the conveyor sortation system from performance evaluation and design perspectives employing continuous modelling approaches. We present two continuous conveyor models (“Delay and Stock Model” and “Batch on Conveyor Model”) with different representation accuracy in a unified mathematical framework. Based on the Batch on Conveyor Model, we develop a fast fluid simulation methodology. We focus on the feasibility of implementing fluid simulation from modelling capabilities, algorithm design and simulation performance in terms of accuracy and simulation time. First, we model the performance evaluation problem as a class of dynamic network flow problems by using Delay and Stock Model. Not only does this model give us the performance metric, but it also provides us with an analytical form of the sub gradient of the performance metric with respect to the design parameters. Second, we adopt the Batch on Conveyor Model and employ fluid simulation as a performance evaluation tool. We investigate the approach on a two-segment tandem conveyor system which is the building block of more complex systems. For this system, we derive a sensitivity estimator by applying infinitesimal perturbation analysis (IPA) and study the performance of this estimator through numerical experiments.