TUNING A PH PID CONTROLLERJulia FletcherRenee ChuangAnthony YeomanJiayue Yu University of California, San DiegoJacobs School of Engineering

A batch system, with a strong acid and base was under investigation.

Transmits Signal

(http://ucsd-ceng-176.wikia.com)

The PBS solution was titrated to identify the buffer region.

0 20 40 60 80 100 120 140 160 1800

2

4

6

8

10

12Titration Curve

Time(s)

pH

Buffer Region = 6.5 - 7.8 pH

An open loop step change was used to determine Kp & of the

system.

KKp: .000954

: 24.17

The Direct synthesis method was used to derive equations for controller coefficients.

System Model

Controller Coefficients

The coefficients found via direct synthesis was observed to reach set point at 120 seconds.

0 20 40 60 80 100 120 140 1606.8

7

7.2

7.4

7.6

7.8

8

8.2

Time(s)

pH

24.17

Controller coefficients were doubled and compared to each other.

0 20 40 60 80 100 120 1406.8

7

7.2

7.4

7.6

7.8

8

8.2

Double KcDouble tau_deriDirect SynthesisSet point

Time(s)

pH

In summary, direct synthesis is a favorable tuning method when trying to control pH.

(www.setis-systems.com)

In summary, direct synthesis is a favorable tuning method when trying to control pH.

Questions?(www.setis-systems.com)