For each part, select all answers that apply

Part A) How does a Feedforward controller work?

a. The manipulated variable is measured, and disturbance is adjusted using a model to reduce its impact on the controlled variable. b. The disturbance is measured, and the manipulated variable is adjusted to reject the impact disturbance has on the controlled variable. c. A process model that related how Disturbance affects the process is used to adjust the manipulated variable. d. Set point changes are made to the inner loop to reduce the disturbance impact on the process variable in the outer loop.

Part B) What characteristic(s) of a Feedforward controller improves disturbance rejection?

a. The settling time for the manipulated variable is accelerated by the process model. b. The control element used to adjust the controlled variable responds aggressively. c. The model relating disturbance to controlled variable minimizes process dynamics and improves system stability. d. An inner loop provides advanced warning of how disturbance impacts the process.

Part C) If you use a Feedforward controller, what must be true about the process disturbance?

a. The control system must respond much faster to disturbance changes than changes to the set point. b. The control model must accurately relate how disturbance impacts the controlled variable. c. The process dead time must be shorter than the disturbance dead time.

Part D) Which control system is more expensive to implement (why)?

a. Cascade controller compared to a Feedback controller; b. Feedforward controller compared to PI Feedback controller; c. A Feedback controller compared to a Cascade controller; d. Feedforward with Feedback Trim compared to a Cascade Controller;

Part E) Why does a SOPDT model take more time to implement than a FOPDT model?