PREDICTIVE GRADE OPTIMIZATION IN CRUISE CONTROL

A cruise control method includes: receiving, by a controller of the vehicle, a set speed, a maximum allowed speed, and a minimum allowed speed, wherein each of the maximum allowed speed and the minimum allowed speed is a speed boundary of an allowed speed range; commanding, by the controller, a propulsion system to produce a commanded axle torque to maintain the set speed; monitoring a current speed of the vehicle; monitoring an elevation of a terrain at predetermined-upcoming locations of the vehicle based on upcoming elevation data from a map database; generating an elevation look-ahead table using the elevation of the terrain at the predetermined-upcoming locations of the vehicle; and determining projected speeds of the vehicle at each of the predetermined-upcoming locations of the vehicle as a function of the current speed of the vehicle and the elevation of the terrain at the predetermined-upcoming locations.