analogy

You hop into the shower. Eee, that’s cold! Your hand flips it up to hot. A few seconds (or minutes, depending on your geographical location and the power of your water heater) later and now it’s omg hot hot hot. Somewhere in there you manage to flip it back to a tolerable level and finish your shower. You are actually acting as a sophisticated controller/feedback system. Your skin is serving as a temperature sensor and feeding back information to your brain that tells you if it’s too hot or too cold. Your hand is serving as the motor that uses signals from your brain to tell you which direction to flip the nozzle in and by how much. Control systems are everywhere. They control everything from the total travel and position of a complicated robot arm in an automotive factory to the flap position of an aileron on an aircraft […]