chapter14

Chapter 13 FEEDBACK PERFORMANCE

Check Your Reading Study Questions Thought Questions

The questions will be categorized according to the key concepts in the Chapter.

PROCESS FACTORS	CONTROL SYSTEMS FACTORS
FREQUENCY RESPONSE	DYNAMIC SIMULATION

Check Your Reading

Solidify the Concepts

13.1
Which of the following are considered when evaluating control performance?

	Dynamic behavior of the controlled variable.
	Dynamic behavior of the manipulated variable.
	The sensitivity of the dynamic behavior to (reasonable) changes in the feedback dynamics.
	None of the above.

13.2
A dynamic simulation is limited to linear process models and controller calculations.

Dynamic Simulation

TRUE FALSE

13.3
We can perform a dynamic simulation of a control system for which of the following inputs?

Dynamic simulation

The input in the process shown in the sketch could be T_in.

13.4
Frequency response calculations are limited to linear process models and controllers.

Frequency response

TRUE FALSE

NOTE:

When we say "frequency response" here, we mean the simplified calculation by setting s = jw in the transfer function, for example,

13.5
The closed loop frequency response for a proportional only controller is given in the equation below. We conclude that as the controller gain (Kc) goes to infinity, the performance becomes very good,

|CV(jw)|goes to 0.0

Frequency Response

TRUE FALSE

Frequency response for closed-loop:

13.6
A Bode Plot below shows the amplitude of the output for a specific value of the input frequency.

Frequency Response

TRUE FALSE

13.7
Which of these control loop element dynamics affect control performance?

Loop Elements

Engineers must select the appropriate equipment for each element.

	Electrical Transmission			Signal Conversion
	Pneumatic Transmission			Process
	Sensor			Controller Calculation
	Final Element, Valve

	Step change.
	Sine.
	Ramp.
	Random variable.