ROBOCUT Scheduling and Configurator

Abstract

This master thesis is a part of the ROBOCUT research project. The project’s vision is to develop a revolutionary new laser cutting technology, ROBOCUT, which relies on a multi-beam principle, where the cutting process is performed with a complex laser beam pattern rather than a traditional single round laser beam. The thesis focuses on two separate parts. Part I focuses on scheduling of the laser cutting process, while Part II defines a methodology for modularizing a production unit and preparing it for configuration. Scheduling of the laser cutting process The RLC problem is researched based on a roll formed part from Ib Andresen. A solution of the scheduling problem using the basic dispatching rules is attempted first, however as they are only able to construct a path in terms of a single objective they do not yield some feasible solutions. In an effort to improve the solutions, it is attempted to combine the basic dispatching rules into composite dispatching rules that are able to handle multiple objectives. Doing so does increase the performance of the obtained solutions, however the composite dispatching rules prove to be difficult to compose in a way that will yield consistent results across different problem instances. In addition these methods did not guarantee an optimal solution. In order to achieve optimal solutions, a combinatorial optimization scheduler is explored and implemented next. The implementation uses branch and bound to find the optimal solutions. This can be done for up to 25 nodes with a computation time around 6 minutes. The solutions obtained through combinatorial optimization is then analyzed in terms of the fastest obtainable on-the-fly cutting of the example part. From this it is concluded that an on-the-fly cutting of the example part using the remote laser cutting can be carried our at a speed of around 200 mm/s. To ease the use of the scheduler, an interface for the CAD application Autodesk Inventor 2011 is developed. This allows a user to easily define the cutting tasks for scheduling, then carry out the scheduling using the developed scheduler and then finally to get a visual presentation of the results. This demonstrates a possible solution to an integrated planning and scheduling system, using the existing applications that the users are accustomed to. Development of a ROBOCUT Configurator With the overall objective of developing a configurator for the remote laser cutting and welding production unit, the second part starts with the identification of a modular architecture. As the idea of developing a configurator for a production has seemingly not been done before, a method for the identification and design of modular products is adapted to fit the modularization of a production unit. By applying this method a modular architecture is identified based on five possible application scenarios of the remote laser cutting and welding technology. The modular architecture is however lacking in terms of fully defining and limiting the number of possible combinations of modules. Finally, the identified modular architecture is used as a basis for the development of an online configurator. The configurator allows a costumer to specify the requirements for the process, and based on this the configurator presents a number of suitable solutions. In the end, the developed configurator is assesed to function well and according to specifications, however it still needs a further development.

A master thesis from Aalborg University

ROBOCUT Scheduling and Configurator