One or more techniques are provided for the sharing of variable
trajectories between multiple controllers in a control system. In
general, the present technique is based upon the sharing of predicted
desired variable trajectories between multiple controllers requiring a
common input variable. In one embodiment, a common input variable is
shared between two controllers, wherein one controller is tuned to have
dominant control with regard to the shared variable. Each controller
determines and communicates their own desired trajectory for the shared
variable to the other controller and in doing so, the constraints
associated with each controller are shared and honored by the other
controller. Based on the communicated trajectories, the dominant
controller may exercise control over the shared variable, thus improving
overall process control.