Determination of Routing and Sequencing in a Flexible Manufacturing System Based on Fuzzy Logic

AbstractThis paper is concerned with scheduling in Flexible Manufacturing Systems (FMS) using a Fuzzy Logic (FL) approach. Four fuzzy input variables; machine allocated processing time, machine priority, machine available time and transportationpriority are defined. The job priority is the fuzzy output variable, showing the priority status of a job to be selected for next operation on a machine. The model will first assign operation of parts to machines under the given production plan and then determine the input sequence of the assigned operations for each machine based on a multi-criteria scheduling scheme. A complete fuzzy scheduling algorithm is developed to solve the operation allocation and operation scheduling problems in FMS environments aiming to approach the objectives of minimizing mean flowtime, maximizing machine utilization and balancing machine usage. The test results demonstrate the superiority of the fuzzy logic approach in most performance measures.

Controllable Air-bubbles Size Generator Performance with Swirl Flow

Bubbles are widely used for various purposes such as products cleaning, medical treatments, food processing, fishery operations, etc. In a number of recent patents, micro/nano-bubbles generated by a swirl flow have been used in several applications because this method involves low cost and simple design. In addition, it provides high performance as well as the ability to generate very small bubbles. In this research, the controllable bubble size generator, which enables the bubble size to be changed according to the sequence of operations, was devised, and then the performance was investigated. This generator, which is operated with two fluids of air and water, makes bubbles that are divided into smaller bubbles by applying the shear stress with the swirl flow. The generating air bubbles which radiated a light sheet through slit, was taken a picture with the digital camera, and was measured. The relation between the swirl strength and the bubble size/numbers was investigated

Scheduling of flexible manufacturing systems using fuzzy logic

This paper presents a research project undertaken at Industrial Research Institute Swinburne (IRIS) in the area of fuzzy scheduling. The research commenced in March 2001 and the full project is expected to be completed in February 2004. The fuzzy based scheduling model, in this paper, will only deal with the part routing problem. The model will select the best alternative route with multi-criteria scheduling through an approach based on a fuzzy logic. This model is applicable to the scheduling of a flexible manufacturing cell (FMC) and also a multi-machine flexible manufacturing system (MMFMS)