Industrial Control Student Guide Version 1.1 phần 7 pps

Experiment #6: Proportional – Integral – Derivative Control

Page 168 • Industrial Control Version 1.1

Figure 6.9a: Response with Gain = 2, 50% Band

With a gain of 2, note that the response time is slightly faster though there is greater hunting.

Experiment #6: Proportional – Integral – Derivative Control

Industrial Control Version 1.1 • Page 169

Figure 6.9b: Data File Plotted in Excel

Drive with Kp=2

-150

-100

-50

0

50

100

150

200

0.44

21.1

41.7

62.4

83.1

104

124

145

166

186

207

228

248

269

290

310

331

352

Seconds

%Drive

%Err

%P

%Drive

From Figure 6.9b note that at this gain setting the amount of proportional drive (%P) is twice as much as the

error (%Err).

Verify the drive amounts shown in the message window of Figure 6.7a at 96.7F:

Error = __________

%Error = __________

%DrivePROP = __________

%DriveTOTAL = __________

PID Control: 20% Proportional Band, Proportional Gain = 5

Too much gain can be unsuitable for control. Repeat the experiment for a proportional band of 20% at a gain

setting of 5. Kp = 50 in the control settings. Figure 6.10 is our SPL result.