Study Questions

Apply Your Knowledge
11.7  
The digital PID has an approximation of the integral mode that is not exactly the same as the continuous mode.

 

 

The statement is not true, the digital gives exactly the same integral

The digital controller does not give zero steady-state offset

 

The digital controller gives zero steady-state offset with the approximate integral calculation

± Zero steady-state offset is not required with the digital controller

 

 

 

 

 

 

 

 

 

 

 

 

 

 

11.8   
The full position digital PID gives a more accurate calculation of the MV than the velocity digital PID.

 

True

 False

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

11.9  
When we tune a digital PID controller, we obtain tuning that ...

 

Is the same as for a continuous PID

Has a smaller controller gain, Kc.

 

Has a larger integral time, TI.

Is less aggressive.

 

 

 

 

 

 

 

 

 

 

 

 

 

11.10   
To rigorously determine the stability of a system with digital PID, we evaluate the roots of the characteristic equation; if a real part is positive, the system is unstable.

 

True

 False