Examples of Positive & Negative Feedback Loops in Everyday Life
On your bike!
When talking about processes, feedback means looking at the output, or result, evaluating it in some way, and applying some form of correction - either modifying the process or changing the input.
If you allow a process to continue but break the feedback loop, the input cannot ‘know' what the output is doing. The process is likely to go spurious.
Processes have different response times, so the lack of feedback might not show up immediately.
A complex process will contain loops within loops. For example, consider cycling from Ayr to Troon -
The balance mechanism is a short term feedback loop. Am I falling left? Steer left. Am I falling right? Steer right. Many operational skills are governed by similar ‘instinctive' feedback loops.
The road safety mechanism is a medium term (tactical) feedback loop. I am approaching traffic lights. Start to slow down. Here is a parked car. Signal and move out. Notice how the amount of anticipation must match the time required to manoeuvre. This is a fundamental principle of feedback loops.
The destination ‘mechanism' is a long term (strategic) feedback loop. Monitoring of progress is taking place but correction is withheld when, for a short time, the road is not pointing directly towards Troon. Nevertheless the loop exists because without it you would stay on the Ayr - Glasgow road and miss Troon altogether.
When anticipation and process delay are mismatched -
This is one explanation of the "boom and bust" cycle. The checks on the economy are mistimed allowing the whole thing to oscillate between extremes. On a much smaller scale the effect called "hunting" (when an engine's idling speed refuses to stabilise) is also caused by mistimed feedback.
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