This Assessment Instrument is made to show your strengths and abilities in this subject.

Show all your work. Open book & notes. Do as much as you can.

 

 

1

Engineers Cat and Ron have the idea that a controller that is Proportional Integral would be a good idea. They tell Ken that the block diagram would look like this:

 

Ken wants to determine the CLTF, the transfer function , for this closed-loop feedback control system.

The system transfer function is

The controller transfer function is

Which term is the Proportional term? Which term is the Integral term?

Find the closed loop transfer function (CLTF) for this system.

Engineer Ken wants to find the steady-state response to a step change in the Set Point, R(s), for this closed loop system. Do that for him.

Also, find the characteristic equation (CE) for this system.

Finally, comment on the stability of the closed loop feedback system.

Solution:

2

Customers and Control Engineers have different viewpoints. Just like babies and parents with Barney. Customers don't know or care about roots and equations and such stuff. They just want these things--

Stable operation

System output = to Set Point

Fast settling down when they change Set Point

You do some experiments and find that the system is FOPDT with

K = 0.15 cm/%, t = 0.31 min and to = 0.13 min. Recommend a value of Kc. Describe the reasons for your recommendation in words that the customer can understand.
Solution:

 

 

 

 

3

Summarize what important things you can learn from a Bode Plot

 

 

 
Solution:

4

Summarize what important things you can learn from a Root Locus

 

 

 

 
Solution:

5

The graph below is for a system on a closed-loop feedback controller. For this response graph, the Set Point is changed from 440 to 840

Address the questions on page 31 in The Amazing Smith and Corripio

Describe what you observe.

Describe what you can deduce about the controller tuning parameters.

Describe what is helpful about the control system as shown in the response.

Describe what is scary about the control system as shown in the response.

Make suggestions as to what you would change to improve the response.
Solution: