eXperiment: Multi-Input Multi-Output Control System
Primary Objective(s):

Control theory for multiple-input, multiple-output systems.

Secondary Objective(s):

Introduction to Labview programming and data acquisition.


The objective is simple—simultaneously control the water level and temperature in a tank.

Separate hot and cold water streams enter the tank. The flowrates of these incoming streams are each computer-controlled. The water temperatures are measured but not controlled nor available as a control input.

The tank has an outlet at the bottom with a flowrate that is neither controlled nor measured. The temperature of this outlet stream is measured. The tank also has an overflow near the top of the tank.

A pressure sensor is used to measure the water level in the tank.

Students must first test and calibrate two mass flow controllers, three thermocouples and one pressure sensor. They must then implement PI, PD or PID control schemes in Labview and select appropriate gains based on control objectives and system performance to external disturbances. On the last day of class, we test the robustness of the control scheme to severe disturbances.