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.
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.
