Presentation is loading. Please wait.

Presentation is loading. Please wait.

FIGURE 12.1 Two variable process-control loops that interact. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson.

Similar presentations


Presentation on theme: "FIGURE 12.1 Two variable process-control loops that interact. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson."— Presentation transcript:

1 FIGURE 12.1 Two variable process-control loops that interact. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

2 FIGURE 12.2 A compound system for which the ratio of two flow rates is controlled. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

3 FIGURE 12.3 Circuit for Example Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

4 FIGURE 12.4 General features of a cascade process-control system. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

5 FIGURE 12.5 Cascade control often provides better control than direct methods. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

6 FIGURE 12.6 Flowchart for an interactive control problem. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

7 FIGURE 12.7 Loop disturbances can occur from intentional setpoint changes or changes in process load. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

8 FIGURE 12.8 Instability in a process-control loop refers to the uncontrolled growth of the controlled variable. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

9 FIGURE 12.9 Tuning determines the reaction of a controlled variable to changes. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

10 FIGURE In one type of cyclic response, the system is adjusted to make each peak down to one-quarter of the previous peak. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

11 FIGURE The minimum-area tuning response characteristics. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

12 FIGURE Error versus time for Example Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

13 FIGURE A transfer function changes the amplitude and phase of a sinusoidal input. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

14 FIGURE This control loop has been opened so that the effect of a disturbance on the loop can be traced. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

15 FIGURE This figure suggests how an initial transient oscillation can grow under the appropriate feedback conditions. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

16 FIGURE A Bode plot shows the open-loop gain and phase versus frequency of an applied sinusoid. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

17 FIGURE Process-reaction graph for loop tuning. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

18 FIGURE Process-reaction graph for Example Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

19 FIGURE Bode plot for Example Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

20 FIGURE Bode plots showing proportional, integral, and derivative mode contributions. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

21 FIGURE Bode plots for Example The proportional mode does not affect phase. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

22 FIGURE Circuit for Problem Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

23 FIGURE Process-reaction graph for Problem Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

24 FIGURE Bode plot for Problems and Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

25 FIGURE Bode plot for Problem Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

26 FIGURE Bode plot for Problem Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

27 FIGURE Process-reaction graph for Problem Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

28 FIGURE Bode plot for Problem Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

29 FIGURE Process-reaction graph for Problem S12.1. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.


Download ppt "FIGURE 12.1 Two variable process-control loops that interact. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson."

Similar presentations


Ads by Google