Designing PID Controller using LabVIEW for Controlling Fluid Level of Vessel

摘要

The primary aim of our project is to replace the PID instrument with virtual PID that has equal controlling capabilities as that of instrument. This designing is possible on software called LabVIEW developed by National Instruments. We also intend to use a DAQ card for interfacing with the hardware. This DAQ card is product of the same company National Instruments. The hardware is a Multiloop Trainer Kit mounted with a tank whose level has to be controlled using a feedback control loop. The flow of project execution is: The designed PID will be generating the necessary controlling electronic signal. This signal will be acquired by DAQ card. The DAQ card transfers it to the I to P converter which will convert the electrical pulses 4-20mA into pneumatic signal 3-15psig to actuate the control valve. This conversion take place as the control valve acts on pneumatic signals only. The control valve controls the fluid flow to maintain the fluid level in tank. The tank is fitted with a capacitive level sensor and a transmitter. This assembly takes the level readings from tank and transmits it to the DAQ card. These values are called process values and are further processed into the designed PID. This way a closed loop system is formed