Feedforward

textbooks

More often than not, textbooks on Control Theory are called "Modern Feedback Control" or some variant of that title. This means that they start at a late point in the game. The more obvious starting point would be feedforward control. As a professor at Cranfield University once told me :

"You use feedforward to get it right. And then you use feedback to mop up the fact that you got it wrong".

feedforward

When you drive a car, you turn the steering wheel, and the car turns more or less as expected. There is no feed­back in the car, in the sense that it would correct itself to give a better turn.

  The only feedback is provided by you. If the turn is not exactly what you hoped for, then you correct a little. At the same time, you monitor the road and traffic around you, and correct for that too. Of course, modern cars have a lot of internal feedback loops to control the engine and what have you. But as for steering, until recently ( with lane keeping systems and autonomous cars ) the car itself has no feedback. You yourself are the one closing the loop.

  The same holds for almost any other activity. When you chop wood, you estimate how hard you need to hit with the axe to split the block. When you cook dinner, you turn up the stove to the value you estimate is going to give the right temperature.

  All of this is feedforward control, and a very common way of control it is.