Fuzzy Control of Grain Drying Process

This paper presents the application of fuzzy logic controller (FLC) to a grain dryer plant. Grain dryer plant is very difficult to control due to long delay process and non-linear behaviour. The controller consists of two inputs; error between actual grain moisture content and set-point, and rate of change of error. There is one fuzzy output that is used to drive the grain flow rate. Simulation tests have been carried out using the process model developed by Liu and Bakker-Arkema (2001) for a cross flow grain dryer. The overall results from the tests are good and the fuzzy logic controller is stable and robust towards input disturbance. Although the design process of fuzzy logic controller is simple; however it provides very fast response to make the grain output moisture content close to the set-point and to reject disturbance exists during the grain drying process.