25.8 PRACTICE PROBLEM SOLUTIONS

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1. Feedback control, more specifically negative feedback, can improve the stability and accuracy of a control system.

2. A PID controller will compare a setpoint and output variable. If there is a persistent error, the integral part of the controller will adjust the output to reduce long term errors.

3. A PI controller

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5. Logical control is more popular because the system is more controllable. This means either happen, or they don't happen. If a system requires a continuous control system then it will tend to be unstable, and even when controlled a precise values can be hard to obtain. The need for control also implies that the system requires some accuracy, thus the process will tend to vary, and be a source of quality control problems.

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