Browsing by Author "Havenga, Pieter-Jan"

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    Pallet routing strategies for a reconfigurable conveyor.
    (Stellenbosch : Stellenbosch University, 2017-03) Havenga, Pieter-Jan; Basson, A. H.; Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering.
    ENGLISH ABSTRACT: A reconfigurable manufacturing system is characterized by high customizability and a high throughput rate. The research presented in this thesis considers a reconfigurable approach to the path planning of a palletized conveyor. Reconfigurability here implies minimizing pallet transportation time by selection of the quickest routes. Previous research by the Mechatronics, Automation and Design Research Group of Stellenbosch University developed a holonic controller for a palletized, modular conveyor. The focus in this thesis was to adapt this controller to include the functionality of path optimization. Simulation software was used to simulate the palletized conveyor and construct a path optimization tool. Simio was the simulation software used. The virtual conveyor setup was constructed in Simio and, together with the Simio application programming interface (API), enabled predicting the travelling times of pallets on the conveyor. For the virtual conveyor the PLCs operating the conveyor were substituted by DLLs which were written in C#. This substitution of the hardware was to ensure that with only minor changes, the existing controller could also control the virtual conveyor. The predicted travelling times for the different routes were recorded, from which the quickest path was selected. Experiments were conducted on an experimental setup of a reconfigurable assembly system to verify that reconfigurability was rapid and reliable. A traffic junction was set up to compare performances of the controller without path optimization with the controller which has the path optimization installed. The results confirmed that simulation can be considered as a way to add reconfigurability to the path planning of a conveyor in a manufacturing system. Latency, however, proved to be a concerning factor when utilizing a holonic controller in running simulations. The holonic controller integrated with the simulations, was substituted with a controller that was developed in the simulation software itself. This approach alleviated the problem of latency found in the previous approach, and lent credibility to having a simulation controller as an optimizing tool to the path planning of a reconfigurable conveyor.