Publication Date

2007

Document Type

Thesis

Committee Members

Kuldip Rattan (Advisor)

Degree Name

Master of Science in Engineering (MSEgr)

Abstract

Using Intelligent Control Methodology Home coffee machines have improved over time with the addition of features such as self-activating timers and crude temperature controlled heating elements. However, home coffee brewer development has stagnated and has yet to achieve full automation status. Present coffee machines leave the user burdened with the mundane and messy task of preparing the coffee maker every time. Also, should the user decide to prepare less than an entire pot, he/she must estimate the correct amount of water and coffee to add. This can lead to a weak or strong brew, giving undesirable results. In order to make another pot, the user is then forced to clean the used coffee grounds and remove any unused coffee. The objective of this thesis is to design and construct a functional, fully automated coffee maker. The coffee maker, with its need for user input, varying grounds and water volume necessity, and sequential method of operation, is a prime candidate for fuzzy control implementation. The main focus of this project is a controller, which is implemented on a standard 486 computer running Linux Red Hat 7. The system is included in this project, but only as a means to test the functionality and efficiency of the controller. User input includes the amount of coffee desired, the strength of that coffee, and the ratio of regular to decaffeinated. These input variables can be effectively and easily defined by fuzzy membership functions. Also, when the coffee maker is not making coffee, the processor monitors water temperature for the next time it is needed and performs any necessary cleaning. Results demonstrate that the water and coffee temperatures can be kept within a tolerance of three degrees Fahrenheit. The open-loop coffee-dispensing controller is validated by expert evaluation since taste is the deciding factor. The efficiency of the water controller is determined by the accuracy of the volume of water obtained. Overshoot and steady-state-error are kept within strict tolerances for this specific application.

Page Count

132

Department or Program

Department of Electrical Engineering

Year Degree Awarded

2007

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