The Application of State Variable Feedback Control to Fermentation Process

Abstract

The PID control technique uses open loop transfer function analysis and feedback compensator design. By using this technique, it is difficult to control non-linear and time varying systems, then a closed loop pole placement technique has been introduced in modern control process and it is widely used in the state variable feedback control.

The application of state variable feedback control to the fermentation process is proposed in this paper. A microprocessor based state variable feedback controller has been designed and constructed for controlling a baker yeast fermentation process system fed by molasses. The controller receives state variables from a sensor and the variables are provided in matrix form.This paper also includes state observer method for calculate the gain of the controller.

The experimental results show that this controller can control multivariable at the same time, ensure the accuracy of set point value, and transmit data to computer for analysis by serial port of controller. This design emphasizes on easy data entering. The results can be shown by LCD display or printer. This method also increases quality control for the process.