Feed forward (control)

The feedforward control refers to a member of the controller design, which is applied, the manipulated variable having a value that is independent of the states of the controlled system and the resulting measurements. The feedforward control permits the consideration of the basis of the setpoint characteristic of anticipated manipulated variable demand. Since it is a control, it can jeopardize improve the control response without stability. Analog also measured disturbance can be switched. In this case one speaks of feedforward control.

Examples

Position control

In the position control, a reference profile for velocity and acceleration is generated when a setpoint step for the position usually. According to the setpoint curve and a linearized distance behavior will be charged a feedforward control that would position the linearized distance corresponding to the reference profiles without further manipulated variable proportions. The actual controller, so the other manipulated variable proportions, then only have to compensate nonlinearities and unknown external influences.

Climate controls in automobiles

Most air conditioning systems of automobiles into account the external influence of the outside temperature and sunlight by a feedforward control. Here, a value proportional to the difference of outdoor temperature and indoor temperature and a further proportion is applied to the intensity of sunlight, the manipulated variable in essence. The heat transfer from the outside can be neutralized. To some extent, other influences such as open windows (convection) and the number of persons in the vehicle ( internal heat sources ) are considered in climate regulation through learning pilot controls.