I have a model of car, my aim is to make a simple model of adaptive cruise control. The only input to this model is a user set distance (range 2 to 50 meters), this is the distance that our vehicle should maintain between itself and the leading vehicle. I plan to control this using throttle and brakes, presently I am controlling only throttle using PI controller, and hence I am able to follow a car which moves with a fixed velocity and does not slow down in middle ( the leading car should not slow down because the following car does not have brakes, so its not possible to slow the following car). Now I want to introduce brake controller, and I need some suggestions or guidance with respect to how can I have two controller in parallel i.e one for throttle and one for brakes. Note: I am doing all this using Simulink.