Feedforward
The feedforward control refers to a member of the controller design that the manipulated variable applied to a value independent of the states of the controlled system and the resulting measurements. The feedforward control enables the control variable requirement that is to be expected based on the setpoint curve to be taken into account . Since it is a controller , it can improve leadership behavior without endangering stability.
Measured disturbance variables can also be applied in the same way. In this case one speaks of feedforward control .
Examples
Position control
With position control , a reference profile for speed and acceleration is usually generated for a setpoint jump for the position . A feedforward control is calculated based on the setpoint profile and a linearized system behavior, which would position the linearized system according to the reference profiles without further manipulated variables. The actual controller, i.e. the other manipulated variable components , then only have to compensate for non-linearities and unknown external influences.
Climate controllers in automobiles
Most automobile air conditioning systems take into account the external influence of outside temperature and solar radiation through a pre-control. Essentially, a value proportional to the difference between the outside and inside temperature is applied to the manipulated variable, as well as a further value proportional to the intensity of the solar radiation. So the heat transfer from the outside can be neutralized.
In some cases, other influences such as open windows ( convection ) and the number of people in the vehicle (internal heat sources ) are also taken into account in climate controllers .