Tag Archives: close loop control

Feedforward control

Feedback control works on the principle of information from the outlet of a process being “fed back” to the input of that process for corrective action. A block diagram of feedback control looks like a loop: The reason any control system is necessary at all to maintain a process variable at some stable value is the existence… Read More »

Closed loop control system

If liquid flow-control valve is opened in a step-change fashion, flow through the pipe tends to selfstabilize at a new rate very quickly. The following illustration shows a typical liquid flow control installation, with a process trend showing the flow response following a manual step-change in valve position: The defining characteristic of a self-regulating process is its… Read More »